WorldWideScience

Sample records for fast-growing tree species

  1. Chemical composition and fuel wood characteristics of fast growing tree species in India

    Science.gov (United States)

    Chauhan, S. K.; Soni, R.

    2012-04-01

    India is one of the growing economy in the world and energy is a critical input to sustain the growth of development. Country aims at security and efficiency of energy. Though fossil fuel will continue to play a dominant role in energy scenario but country is committed to global environmental well being thus stressing on environment friendly technologies. Concerns of energy security in this changing climatic situation have led to increasing support for the development of new renewable source of energy. Government though is determined to facilitate bio-energy and many projects have been established but initial after-affects more specifically on the domestic fuelwood are evident. Even the biomass power generating units are facing biomass crisis and accordingly the prices are going up. The CDM projects are supporting the viability of these units resultantly the Indian basket has a large number of biomass projects (144 out of total 506 with 28 per cent CERs). The use for fuelwood as a primary source of energy for domestic purpose by the poor people (approx. 80 per cent) and establishment of bio-energy plants may lead to deforestation to a great extent and only solution to this dilemma is to shift the wood harvest from the natural forests to energy plantations. However, there is conspicuous lack of knowledge with regards to the fuelwood characteristics of fast growing tree species for their selection for energy plantations. The calorific value of the species is important criteria for selection for fuel but it is affected by the proportions of biochemical constituents present in them. The aim of the present work was to study the biomass production, calorific value and chemical composition of different short rotation tree species. The study was done from the perspective of using the fast growing tree species for energy production at short rotation and the study concluded that short rotation tree species like Gmelina arborea, Eucalyptus tereticornis, Pongamia pinnata

  2. Hydroponic Screening of Fast-growing Tree Species for Lead Phytoremediation Potential.

    Science.gov (United States)

    Yongpisanphop, Jiraporn; Babel, Sandhya; Kruatrachue, Maleeya; Pokethitiyook, Prayad

    2017-10-01

    Using trees as phytoremediators has become a powerful tool to remediate lead from contaminated environments. This study aims to identify potential candidates among fast-growing trees by comparing their ability to tolerate and accumulate Pb. Cuttings from Acacia mangium, Azadirachta indica, Eucalyptus camaldulensis, and Senna siamea were cultured in 25% modified Hoagland's solutions supplemented with 10, 30, and 50 mg/L Pb for 15 days. Lead concentrations were determined by a flame atomic absorption spectrophotometer. All species showed high Pb tolerance (over 78%) and low translocation factor (40000 mg/kg) was recorded in A. mangium and E. camaldulensis grown in 50 mg/L Pb solution. Based on high biomass, tolerance index, and Pb content in plants, A. mangium and E. camaldulensis are good candidates for phytoremediation.

  3. Understory vegetation in fast-growing tree plantations on savanna soils in Congo

    OpenAIRE

    Loumeto, J.J.; Huttel, Charles

    1997-01-01

    The hypothesis that tree plantations may catalyze the regeneration of natural forest biodiversity was tested through studies of floristic diversity and structure in fast-growing tree plantations in the Congo. Study sites included experimental and industrial plantations on poor sandy coastal soils near Pointe-Noire, and experimental plantations on clay soils near Loudima. The effects of plantations species, plantation age (in 6- to 20-year-old eucalypt stands), disturbance due to herbicide use...

  4. INITIAL SCREENING OF FAST-GROWING TREE SPECIES BEING TOLERANT OF DRY TROPICAL PEATLANDS IN CENTRAL KALIMANTAN, INDONESIA

    Directory of Open Access Journals (Sweden)

    Hideyuki Saito

    2005-07-01

    Full Text Available An investigation of the recruit, survivorship and growth of naturally regenerating tree species on canal bank was conducted to  select tree species which are suitable for preceding planting in drained and burnt peat swamp lands in  Central Kalimantan, Indonesia.  Top of  the canal bank were open, with greater soil moisture  deficit and higher soil temperatures than on the next intact forest floor. The abundant  trees were asam-asam (Ploiarium alternifolium,garunggang (Cratoxylon arborescens and tumih (Combretocarpus rotundatus. New regeneration of these trees on the canal bank was confirmed during this investigation and mortality was very low. These results indicated that P. alternifolium,C. arborescens and C. rotundatuswere tolerant of intensive radiation, soil drought and high soil temperatures during germination. The annual height increments  were 189-232  cm y-1 (P. alternifolium,118-289  cm y-1  (C. arborescensand 27-255 cm y-1   (C. rotundatus; thus, these three species could be classified as fast-growing with tolerance to open and dry conditions.  Such characteristics were important to avoid competition with herbs, ferns,and/ or climbers. The results·suggest that P.alternifolium,C. arborescens and C. rotundatusare suitable for preceding planting for the rehabilitation of the disturbed peat swamp forests of Central Kalimantan.

  5. Water regime of mechanical-biological pretreated waste materials under fast-growing trees.

    Science.gov (United States)

    Rüth, Björn; Lennartz, Bernd; Kahle, Petra

    2007-10-01

    In this study mechanical-biological pre-treated waste material (MBP) was tested for suitability to serve as an alternative surface layer in combination with fast-growing and water-consumptive trees for final covers at landfill sites. The aim was to quantify evapotranspiration and seepage losses by numerical model simulations for two sites in Germany. In addition, the leaf area index (LAI) of six tree species over the growing season as the driving parameter for transpiration calculations was determined experimentally. The maximum LAI varied between 3.8 and 6.1 m2 m(-2) for poplar and willow clones, respectively. The evapotranspiration calculations revealed that the use of MBP waste material for re-cultivation enhanced evapotranspiration by 40 mm year(-1) (10%) over an 11 year calculation period compared to a standard mineral soil. Between 82% (for LAI(max) = 3.8) and 87% (for LAI(max) = 6.1) of the average annual precipitation (506 mm) could be retained from the surface layer assuming eastern German climate conditions, compared with a retention efficiency between 79 and 82% for a mineral soil. Although a MBP layer in conjunction with water-consumptive trees can reduce vertical water losses as compared to mineral substrates, the effect is not sufficient to meet legal regulations.

  6. Wood-plastic composites utilizing wood flours derived from fast- growing trees common to the midwest

    Science.gov (United States)

    There are several non- or under-utilized hardwood trees common to the Midwestern states. Wood flour (WF) derived from fast-growing Midwest trees (Osage orange, Black Locust and Red Mulberry) were evaluated as a source of bio-based fiber reinforcements. Wood plastic composites (WPC) of high density p...

  7. Do persistently fast-growing juveniles contribute disproportionately to population growth? A new analysis tool for matrix models and its application to rainforest trees.

    Science.gov (United States)

    Zuidema, Pieter A; Brienen, Roel J W; During, Heinjo J; Güneralp, Burak

    2009-11-01

    Plants and animals often exhibit strong and persistent growth variation among individuals within a species. Persistently fast-growing individuals have a higher chance of reaching reproductive size, do so at a younger age, and therefore contribute disproportionately to population growth (lambda). Here we introduce a new approach to quantify this "fast-growth effect." We propose using age-size-structured matrix models in which persistently fast and slow growers are distinguished as they occur in relatively young and old age classes for a given size category. Life-cycle pathways involving fast growth can then be identified, and their contribution to lambda is quantified through loop analysis. We applied this approach to an example species, the tropical rainforest tree Cedrela odorata, that shows persistent growth variation among individuals. Loop analysis showed that juvenile trees reaching the 10-cm diameter class at below-median age contributed twice as much to lambda as slow juvenile growers. Fast growth to larger-diameter categories also contributed disproportionately to lambda. The results were robust to changes in parameter values and life-history trade-offs. These results show that the fast-growth effect can be strong in long-lived species. Persistent growth differences among individuals should therefore be accommodated for in demographic models and life-history studies.

  8. Fast Tree: Computing Large Minimum-Evolution Trees with Profiles instead of a Distance Matrix

    OpenAIRE

    N. Price, Morgan

    2009-01-01

    Gene families are growing rapidly, but standard methods for inferring phylogenies do not scale to alignments with over 10,000 sequences. We present FastTree, a method for constructing large phylogenies and for estimating their reliability. Instead of storing a distance matrix, FastTree stores sequence profiles of internal nodes in the tree. FastTree uses these profiles to implement neighbor-joining and uses heuristics to quickly identify candidate joins. FastTree then uses nearest-neighbor i...

  9. FastTree: Computing Large Minimum Evolution Trees with Profiles instead of a Distance Matrix

    OpenAIRE

    Price, Morgan N.; Dehal, Paramvir S.; Arkin, Adam P.

    2009-01-01

    Gene families are growing rapidly, but standard methods for inferring phylogenies do not scale to alignments with over 10,000 sequences. We present FastTree, a method for constructing large phylogenies and for estimating their reliability. Instead of storing a distance matrix, FastTree stores sequence profiles of internal nodes in the tree. FastTree uses these profiles to implement Neighbor-Joining and uses heuristics to quickly identify candidate joins. FastTree then uses nearest neighbor in...

  10. Nitrogen fixation in four dryland tree species in central Chile

    International Nuclear Information System (INIS)

    Ovalle, C.; Arredondo, S.; Aronson, J.; Longeri, L.; Avendano, J.

    1998-01-01

    Results are presented from a 5-year experiment using 15 N-enriched fertilizer to determine N 2 fixation in four tree species on degraded soils in a Mediterranean-climate region of central Chile in which there are 5 months of drought. Species tested included three slow-growing but long-lived savannah trees native to southers South America, (acacia caven, Prosopic alba and P. chilensis; Mimosoideae), and Tagasaste (Chamaecytisus proliferus ssp. palmensis; Papilonoideae), a fast-growing but medium-lived tree from the Canary Islands. Tagasaste produced four- to twenty-fold more biomass than the other species, but showed declining N 2 fixation and biomass accumulation during the 5th year, corresponding to the juvenile-to-adult developmental transition. Nitrogen content was significantly higher in Tagasaste and Acacia caven than in the other species. The data revealed inter-specific differences in resource allocation and phenology of N 2 fixation rarely detailed for woody plants in dryland regions. (author)

  11. Plant diversity and energy potency of community forest in East Kalimantan, Indonesia: Searching for fast growing wood species for energy production

    Directory of Open Access Journals (Sweden)

    RUDIANTO AMIRTA

    2016-05-01

    Full Text Available Abstract. Amirta R, Yuliansyah, Angi EM, Ananto BR, Setiyono B, Haqiqi MT, Septiana HA, Lodong M, Oktavianto RN. 2016. Plant diversity and energy potency of community forest in East Kalimantan, Indonesia: Searching for fast growing wood species for energy production. Nusantara Bioscience 8: 22-30. Nowadays, there is an increasing interest in intensifying the production and use of biomass to replace fossil fuels for the production of heat and electricity, especially for a remote area that generally abundance with the wood biomass resources including in East Kalimantan, Indonesia. In this work, diversity of plant species that commonly growth in community forest area of East Kutai District, East Kalimantan, Indonesia had been studied to point out their energy potency to be used as biomass feedstock for the electricity generated. Diversity of plant species in the community forest was evaluated by making 13 sampling plots with 20mx20m size approximately. Concurently, the energy properties of plant biomass such as proximate and ultimate compositions were also analyzed using ASTM methods. Results showed that more than 30 species of tropical trees and wood shrubs were grown in the community forest. The presence of them was classified into two different growth of origins: natural and artificial plantation, and also three different categories of plant resources: tree species from logged over forest, commercial fast growing plant tree species for the fiber production and woody shrubs. The highest dominancy and productivity was found in Paraserianthes falcataria (L. Nielsen since the wood biomass was artificially planted for the commercial purposes. Among the 31 plant species analyzed we found the highest energy potency was obtained from Cratoxylum cochinchinense (Lour. Blume that produced 3.17 MWh/ton, and the lowest was from Trema orientalis (L. Blume 0.97 MWh/ton. The woody shrubs species such as Vernonia amigdalina Delile., Piper aduncum L., Gliricidia

  12. Carbonization of some fast-growing species in Sudan

    Energy Technology Data Exchange (ETDEWEB)

    Khristova, P.; Khalifa, A.W. (Khartoum Univ. (Sudan). Forestry Dept.)

    1993-01-01

    Four wood species, indigenous Acacia seyal (talh) and exotic fast-growing Conocarpus lancifolius (damas), Eucalyptus microtheca (kafur) and Prosopis chilensis (mesquite) grown in Sudan, were assessed and compared as raw materials for charcoal making. The effects of production method (traditional earth mound and improved metal kiln) and the physical and chemical properties of the wood and bark on the yield and quality of charcoal produced were assessed. Regression analyses of wood properties and heat value data indicated high negative correlations of the wood heat value with halocellulose and ash, and high positive correlations with wood density, lignin, and alcohol-benzene and hot-water solubles. Carbonization with the Tropical Products Institute metal kiln produced higher yields (33%) than the traditional earth mound (27%), although the difference in energy transformation yields was found to be insignificant both between appliances and species. (author)

  13. Fast Tree: Computing Large Minimum-Evolution Trees with Profiles instead of a Distance Matrix

    Energy Technology Data Exchange (ETDEWEB)

    N. Price, Morgan; S. Dehal, Paramvir; P. Arkin, Adam

    2009-07-31

    Gene families are growing rapidly, but standard methods for inferring phylogenies do not scale to alignments with over 10,000 sequences. We present FastTree, a method for constructing large phylogenies and for estimating their reliability. Instead of storing a distance matrix, FastTree stores sequence profiles of internal nodes in the tree. FastTree uses these profiles to implement neighbor-joining and uses heuristics to quickly identify candidate joins. FastTree then uses nearest-neighbor interchanges to reduce the length of the tree. For an alignment with N sequences, L sites, and a different characters, a distance matrix requires O(N^2) space and O(N^2 L) time, but FastTree requires just O( NLa + N sqrt(N) ) memory and O( N sqrt(N) log(N) L a ) time. To estimate the tree's reliability, FastTree uses local bootstrapping, which gives another 100-fold speedup over a distance matrix. For example, FastTree computed a tree and support values for 158,022 distinct 16S ribosomal RNAs in 17 hours and 2.4 gigabytes of memory. Just computing pairwise Jukes-Cantor distances and storing them, without inferring a tree or bootstrapping, would require 17 hours and 50 gigabytes of memory. In simulations, FastTree was slightly more accurate than neighbor joining, BIONJ, or FastME; on genuine alignments, FastTree's topologies had higher likelihoods. FastTree is available at http://microbesonline.org/fasttree.

  14. QuickJoin—Fast Neighbour-Joining Tree Reconstruction

    DEFF Research Database (Denmark)

    Mailund; Pedersen, Christian N. Storm

    2004-01-01

    We have built a tool for fast construction of very large phylogenetic trees. The tool uses heuristics for speeding up the neighbour-joining algorithm—while still constructing the same tree as the original neighbour-joining algorithm—making it possible to construct trees for ~8000 species in less...

  15. The variation of methane flux rates from boreal tree species at the beginning of the growing season

    Science.gov (United States)

    Haikarainen, Iikka; Halmeenmäki, Elisa; Machacova, Katerina; Pihlatie, Mari

    2016-04-01

    Boreal forests are considered as net sink for atmospheric methane (CH4) because of the CH4 oxidizing bacteria in the aerobic soil layer. However, within the last decades it has become more evident that trees play an important role in the global CH4 budget by offering pathways for anaerobically produced CH4 from deeper soil layers to the atmosphere. Furthermore, trees may also act as independent sources of CH4. To confirm magnitude, variability and the origin of the tree mediated CH4 emissions more research is needed, especially in boreal forests which have been in a minority in such investigation. We measured tree stem and shoot CH4 exchange of three boreal tree species at the beginning of the growing season (13.4.-13.6.2015) at SMEAR II station in Hyytiälä, located in southern Finland (61° 51'N, 24° 17'E, 181 asl). The fluxes were measured from silver birch (Betula pendula), downy birch (B. pubescens) and Norway spruce (Picea abies) on two sites with differing soil type and characteristics (paludified and mineral soil), vegetation and forest structure by using the static chamber technique. Scaffold towers were used for measurements at multiple stem heights and shoots. The aim was to study the vertical profile of CH4 fluxes at stem and shoot level and compare these fluxes among the studied species, and to observe temporal changes in CH4 flux over the beginning of the growing season. We found that all the trees emitted CH4 from their stems and shoots. Overall, the birches showed higher emissions compared to the spruces. The emission rates were considerably larger in the lower parts of the birch stems than upper parts, and these emissions increased during the growing season. The spruces had more variation in the stem CH4 flux, but the emission rates of the upper parts of the stem exceeded the birch emissions at the same height. The shoot fluxes of all the studied trees indicated variable CH4 emissions without a clear pattern regarding the vertical profile and

  16. Growth and elemental content of two tree species growing on abandoned coal fly ash basins

    International Nuclear Information System (INIS)

    Carlson, C.L.; Adriano, D.C.

    1991-01-01

    Differences in aboveground tissue concentrations of trace elements were assessed for sweetgum (Liquidambar styraciflua L.) and sycamore (Plantanus occidentalis L.) growing on two abandoned coal fly ash basins and a control soil. The wet basin (pH = 5.58) had originally received precipitator ash in an ash-water slurry, while the dry basin (pH = 8.26) had received both precipitator and bottom ash in dry form. In general, trees from the wet basin exhibited elevated trace element concentrations in comparison to the controls, while the dry basin trees exhibited reduced concentrations. On eof the most striking differenced in elemental concentrations among the ash basin and control trees was observed for Mn, with the control trees exhibiting concentrations orders of magnitude greater than the ash basin trees. Differences in foliar trace element concentrations among the sites can generally be explained by differences in substrate trace element concentrations and/or substrate pH. While trees from the wet ash basin generally had the highest trace element concentrations, these trees also attained the greatest height and diameter growth, suggesting that the elevated trace element concentrations in the wet basin substrate are not limiting the establishment of these two species. The greater height and diameter growth of the wet basin trees is presumably a result of the greater water-holding capacity of the substrate on this site. Differences in growth and tissue concentrations between sweetgum and sycamore highlight the importance of using more than one species when assessing metal toxicity or deficiency on a given substrate

  17. CENTRAL KALIMANTAN’S FAST GROWING SPECIES: SUITABILITY FOR PULP AND PAPER

    Directory of Open Access Journals (Sweden)

    Danang Sudarwoko Adi

    2015-04-01

    Full Text Available Recent studies of fast growing species grown in PT. Sari Bumi Kusuma, Central Kalimantan, show that based on their fiber dimensions there are five species, namely Endospermum diadenum, Dillenia spp., Adinandra dumosa, Adiandra sp., and Nauclea junghuhnii with good potential for pulp and paper production. The fiber length of those five wood species are was more than 2,200 µm on average. This paper studies the physical properties, fiber dimensions and their chemical contents to predict the paper and pulp quality. The result shows that all of the species were classified in the medium to high density category. All species were classified into the first class quality for pulp and paper. Based on chemical contents, Dillenia sp. is the most suitable species due to its high value of holocellulose and a-cellulose, low lignin content, and its fiber length is about 3,119 µm on average. A. dumosa also has good opportunities because it had the longest fiber lengths (3,137 µm on average and high value of holocellulose, even though it has the highest lignin content. While Nuclea junghuhnii is less suitable due to low values of holocellulose and a-cellulose.

  18. Socio-economic determinants of growing trees on farms in the middle hills of Nepal

    DEFF Research Database (Denmark)

    Oli, B.N.; Treue, Thorsten; Larsen, Helle Overgaard

    2015-01-01

    were found. The Shannon–Wiener index was 2.46 and Simpson’s Dominance index was 0.15. Trees on farmland contributed on average 43 % of households’ firewood and fodder consumption. Apparent determinants of tree growing were identified through OLS regression; they included size of land and livestock......On-farm tree growing is potentially important for livelihood strategies and forest conservation, and varies greatly according to local contexts. A detailed knowledge base is therefore needed, requiring, inter alia, the documentation of factors associated with growing trees on farms. The present...... study surveyed 304 randomly sampled households in ten community forestry user groups in Nepal, eliciting data on demographics, income and consumption of tree products. All trees on households’ farm land were registered by species. Farmers had on average 65 trees per hectare and a total of 92 species...

  19. Ecological Impact on Nitrogen and Phosphorus Cycling of a Widespread Fast-growing Leguminous Tropical Forest Plantation Tree Species, Acacia mangium

    Directory of Open Access Journals (Sweden)

    Shigehiro Ishizuka

    2011-11-01

    Full Text Available Symbiotic nitrogen fixation is one of the major pathways of N input to forest ecosystems, enriching N availability, particularly in lowland tropics. Recently there is growing concern regarding the wide areas of fast-growing leguminous plantations that could alter global N2O emissions. Here, we highlight substantially different N and phosphorus utilization and cycling at a plantation of Acacia mangium, which is N2-fixing and one of the major plantation species in tropical/subtropical Asia. The litterfall, fresh leaf quality and fine-root ingrowth of A. mangium were compared to those of non-N2-fixing Swietenia macrophylla and coniferous Araucaria cunninghamii in wet tropical climates in Borneo, Malaysia. The N and P concentrations of the A. mangium fresh leaves were higher than those of the other two species, whereas the P concentration in the leaf-litterfall of A. mangium was less than half that of the others; in contrast the N concentration was higher. The N:P ratio in the A. mangium leaf was markedly increased from fresh-leaf (29 to leaf-litterfall (81. Although the N flux in the total litterfall at the A. mangium plantation was large, the fine-root ingrowth of A. mangium significantly increased by applying both N and P. In conclusion, large quantities of N were accumulated and returned to the forest floor in A. mangium plantation, while its P resorption capacity was efficient. Such large N cycling and restricted P cycling in wide areas of monoculture A. mangium plantations may alter N and P cycling and their balance in the organic layer and soil on a stand level.

  20. Differential Macrophage Response to Slow- and Fast-Growing Pathogenic Mycobacteria

    Directory of Open Access Journals (Sweden)

    A. Cecilia Helguera-Repetto

    2014-01-01

    Full Text Available Nontuberculous mycobacteria (NTM have recently been recognized as important species that cause disease even in immunocompetent individuals. The mechanisms that these species use to infect and persist inside macrophages are not well characterised. To gain insight concerning this process we used THP-1 macrophages infected with M. abscessus, M. fortuitum, M. celatum, and M. tuberculosis. Our results showed that slow-growing mycobacteria gained entrance into these cells with more efficiency than fast-growing mycobacteria. We have also demonstrated that viable slow-growing M. celatum persisted inside macrophages without causing cell damage and without inducing reactive oxygen species (ROS, as M. tuberculosis caused. In contrast, fast-growing mycobacteria destroyed the cells and induced high levels of ROS. Additionally, the macrophage cytokine pattern induced by M. celatum was different from the one induced by either M. tuberculosis or fast-growing mycobacteria. Our results also suggest that, in some cases, the intracellular survival of mycobacteria and the immune response that they induce in macrophages could be related to their growth rate. In addition, the modulation of macrophage cytokine production, caused by M. celatum, might be a novel immune-evasion strategy used to survive inside macrophages that is different from the one reported for M. tuberculosis.

  1. Single-tree water use and water-use efficiencies of selected indigenous and introduced species in the Southern Cape region of South Africa

    CSIR Research Space (South Africa)

    Mapeto, P

    2017-03-01

    Full Text Available In South Africa, the development of a plantation tree industry using fast-growing introduced species was accelerated by the limited extent of indigenous forests. However, concerns about the impacts of plantations on the country’s limited water...

  2. Tree species migration studies in the White Mountains of New Hampshire

    Science.gov (United States)

    William B. Leak; Mariko. Yamasaki

    2012-01-01

    The movement of tree species in either latitude or elevation has attracted increased recent attention due to growing national/international concerns over climate change. However, studies on tree species movements began in the early 1970s in the White Mountains of New Hampshire, mostly due to ecological interests in the episodic behavior of upper-elevation tree species...

  3. [Responses of sap flow to natural rainfall and continuous drought of tree species growing on bedrock outcrops].

    Science.gov (United States)

    Zhang, Hui Ling; Ding, Ya Li; Chen, Hong Song; Wang, Ke Lin; Nie, Yun Peng

    2018-04-01

    This study focused on bedrock outcrops, a very common habitat in karst region of southwest China. To reveal the responses of plant transpiration to natural rainfall and continuous drought, two tree species typical to this habitat, Radermachera sinica and Triadica rotundifolia, were selected as test materials. A rainout shelter was used to simulate continuous drought. The sap flow dynamics were monitored using the method of Granier's thermal dissipation probe (TDP). Our results showed that sap flow density increased to different degrees after rain in different stages of the growing season. Sap flow density of the deciduous species T. rotundifolia was always higher than that of the semi-deciduous species R. sinica. After two months without rainfall input, both species exhibited no obvious decrease in sap flow density, indicating that rainfall was not the dominant source for their water uptake, at least in the short-term. Based on the regression relationships between sap flow density and meteorological factors before and after rainfall, as well as at different stages of continuous drought, we found that the dynamics of meteorological factors contributed little to plant transpiration. The basic transpiration characteristics of both species were not changed in the circumstance of natural rainfall and short-term continuous drought, which would be closely related to the special water storage environments of bedrock outcrops and the reliance on deep water sources by tree species.

  4. Phytoextraction of potentially toxic elements by six tree species growing on hazardous mining sludge.

    Science.gov (United States)

    Mleczek, Mirosław; Goliński, Piotr; Krzesłowska, Magdalena; Gąsecka, Monika; Magdziak, Zuzanna; Rutkowski, Paweł; Budzyńska, Sylwia; Waliszewska, Bogusława; Kozubik, Tomisław; Karolewski, Zbigniew; Niedzielski, Przemysław

    2017-10-01

    The aim of the study was to compare the phytoextraction abilities of six tree species (Acer platanoides L., Acer pseudoplatanus L., Betula pendula Roth, Quercus robur L., Tilia cordata Miller, Ulmus laevis Pall.), cultivated on mining sludge contaminated with arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), thallium (Tl), and zinc (Zn). All six tree species were able to survive on such an unpromising substrate. However, A. platanoides and T. cordata seedlings grown on the polluted substrate showed significantly lower biomass than control plants (55.5 and 45.6%, respectively). As, Cd, Cu, Pb, and Tl predominantly accumulated in the roots of all the analyzed tree species with the following highest contents: 1616, 268, 2432, 547, and 856 mg kg -1 , respectively. Zn was predominantly localized in shoots with the highest content of 5801 and 5732 mg kg -1 for U. laevis and A. platanoides, respectively. A. platanoides was the most effective in Zn phytoextaction, with a bioconcentration factor (BCF) of 8.99 and a translocation factor (TF) of 1.5. Furthermore, with the exception of A. pseudoplatanus, the analyzed tree species showed a BCF > 1 for Tl, with the highest value for A. platanoides (1.41). However, the TF for this metal was lower than 1 in all the analyzed tree species. A. platanoides showed the highest BCF and a low TF and could, therefore, be a promising species for Tl phytostabilization. In the case of the other analyzed tree species, their potential for effective phytoextraction was markedly lower. Further studies on the use of A. platanoides in phytoremediation would be worth conducting.

  5. Inferences from growing trees backwards

    Science.gov (United States)

    David W. Green; Kent A. McDonald

    1997-01-01

    The objective of this paper is to illustrate how longitudinal stress wave techniques can be useful in tracking the future quality of a growing tree. Monitoring the quality of selected trees in a plantation forest could provide early input to decisions on the effectiveness of management practices, or future utilization options, for trees in a plantation. There will...

  6. Inferring species trees from incongruent multi-copy gene trees using the Robinson-Foulds distance

    Science.gov (United States)

    2013-01-01

    Background Constructing species trees from multi-copy gene trees remains a challenging problem in phylogenetics. One difficulty is that the underlying genes can be incongruent due to evolutionary processes such as gene duplication and loss, deep coalescence, or lateral gene transfer. Gene tree estimation errors may further exacerbate the difficulties of species tree estimation. Results We present a new approach for inferring species trees from incongruent multi-copy gene trees that is based on a generalization of the Robinson-Foulds (RF) distance measure to multi-labeled trees (mul-trees). We prove that it is NP-hard to compute the RF distance between two mul-trees; however, it is easy to calculate this distance between a mul-tree and a singly-labeled species tree. Motivated by this, we formulate the RF problem for mul-trees (MulRF) as follows: Given a collection of multi-copy gene trees, find a singly-labeled species tree that minimizes the total RF distance from the input mul-trees. We develop and implement a fast SPR-based heuristic algorithm for the NP-hard MulRF problem. We compare the performance of the MulRF method (available at http://genome.cs.iastate.edu/CBL/MulRF/) with several gene tree parsimony approaches using gene tree simulations that incorporate gene tree error, gene duplications and losses, and/or lateral transfer. The MulRF method produces more accurate species trees than gene tree parsimony approaches. We also demonstrate that the MulRF method infers in minutes a credible plant species tree from a collection of nearly 2,000 gene trees. Conclusions Our new phylogenetic inference method, based on a generalized RF distance, makes it possible to quickly estimate species trees from large genomic data sets. Since the MulRF method, unlike gene tree parsimony, is based on a generic tree distance measure, it is appealing for analyses of genomic data sets, in which many processes such as deep coalescence, recombination, gene duplication and losses as

  7. Isoprene emission from tropical tree species

    International Nuclear Information System (INIS)

    Padhy, P.K.; Varshney, C.K.

    2005-01-01

    Foliar emission of isoprene was measured in nine commonly growing tree species of Delhi, India. Dynamic flow enclosure technique was used and gas samples were collected onto Tenax-GC/Carboseive cartridges, which were then attached to the sample injection system in the gas chromatograph (GC). Eluting compounds were analysed using a flame ionisation detector (FID). Out of the nine tree species, isoprene emission was found in six species (Eucalyptus sp., Ficus benghalensis, Ficus religiosa, Mangifera indica, Melia azedarach, and Syzygium jambolanum), whereas, in the remaining three tree species (Alstonia scholaris, Azadirachta indica, and Cassia fistula) no isoprene emission was detected or the levels of emission were negligible or below the detection limit (BDL). Among six tree species, the highest hourly emission (10.2±6.8 μg g -1 leaf dry weight, average of five seasons) was observed in Ficus religiosa, while minimum emission was from Melia azedarach (2.2±4.9 μg g -1 leaf dry weight, average of five seasons). Isoprene emission (average of six species), over five seasons, was found to vary between 3.9 and 8.5 μg g -1 leaf dry weight during the rainy season. In addition, significant diurnal variation in isoprene emission was observed in each species. The preliminary estimate made in this study on the annual biogenic VOC emission from India may probably be the first of its kind from this part of the world. - Isoprene flux (diurnal and seasonal) from some tropical tree species was estimated and a regional comparison was made

  8. Isoprene emission from tropical tree species

    Energy Technology Data Exchange (ETDEWEB)

    Padhy, P.K. [School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)]. E-mail: padhypk2003@yahoo.com; Varshney, C.K. [School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)

    2005-05-01

    Foliar emission of isoprene was measured in nine commonly growing tree species of Delhi, India. Dynamic flow enclosure technique was used and gas samples were collected onto Tenax-GC/Carboseive cartridges, which were then attached to the sample injection system in the gas chromatograph (GC). Eluting compounds were analysed using a flame ionisation detector (FID). Out of the nine tree species, isoprene emission was found in six species (Eucalyptus sp., Ficus benghalensis, Ficus religiosa, Mangifera indica, Melia azedarach, and Syzygium jambolanum), whereas, in the remaining three tree species (Alstonia scholaris, Azadirachta indica, and Cassia fistula) no isoprene emission was detected or the levels of emission were negligible or below the detection limit (BDL). Among six tree species, the highest hourly emission (10.2{+-}6.8 {mu}g g{sup -1} leaf dry weight, average of five seasons) was observed in Ficus religiosa, while minimum emission was from Melia azedarach (2.2{+-}4.9 {mu}g g{sup -1} leaf dry weight, average of five seasons). Isoprene emission (average of six species), over five seasons, was found to vary between 3.9 and 8.5 {mu}g g{sup -1} leaf dry weight during the rainy season. In addition, significant diurnal variation in isoprene emission was observed in each species. The preliminary estimate made in this study on the annual biogenic VOC emission from India may probably be the first of its kind from this part of the world. - Isoprene flux (diurnal and seasonal) from some tropical tree species was estimated and a regional comparison was made.

  9. Development of a gene cloning system in a fast-growing and moderately thermophilic Streptomyces species and heterologous expression of Streptomyces antibiotic biosynthetic gene clusters

    Science.gov (United States)

    2011-01-01

    Background Streptomyces species are a major source of antibiotics. They usually grow slowly at their optimal temperature and fermentation of industrial strains in a large scale often takes a long time, consuming more energy and materials than some other bacterial industrial strains (e.g., E. coli and Bacillus). Most thermophilic Streptomyces species grow fast, but no gene cloning systems have been developed in such strains. Results We report here the isolation of 41 fast-growing (about twice the rate of S. coelicolor), moderately thermophilic (growing at both 30°C and 50°C) Streptomyces strains, detection of one linear and three circular plasmids in them, and sequencing of a 6996-bp plasmid, pTSC1, from one of them. pTSC1-derived pCWH1 could replicate in both thermophilic and mesophilic Streptomyces strains. On the other hand, several Streptomyces replicons function in thermophilic Streptomyces species. By examining ten well-sporulating strains, we found two promising cloning hosts, 2C and 4F. A gene cloning system was established by using the two strains. The actinorhodin and anthramycin biosynthetic gene clusters from mesophilic S. coelicolor A3(2) and thermophilic S. refuineus were heterologously expressed in one of the hosts. Conclusions We have developed a gene cloning and expression system in a fast-growing and moderately thermophilic Streptomyces species. Although just a few plasmids and one antibiotic biosynthetic gene cluster from mesophilic Streptomyces were successfully expressed in thermophilic Streptomyces species, we expect that by utilizing thermophilic Streptomyces-specific promoters, more genes and especially antibiotic genes clusters of mesophilic Streptomyces should be heterologously expressed. PMID:22032628

  10. STRIDE: Species Tree Root Inference from Gene Duplication Events.

    Science.gov (United States)

    Emms, David M; Kelly, Steven

    2017-12-01

    The correct interpretation of any phylogenetic tree is dependent on that tree being correctly rooted. We present STRIDE, a fast, effective, and outgroup-free method for identification of gene duplication events and species tree root inference in large-scale molecular phylogenetic analyses. STRIDE identifies sets of well-supported in-group gene duplication events from a set of unrooted gene trees, and analyses these events to infer a probability distribution over an unrooted species tree for the location of its root. We show that STRIDE correctly identifies the root of the species tree in multiple large-scale molecular phylogenetic data sets spanning a wide range of timescales and taxonomic groups. We demonstrate that the novel probability model implemented in STRIDE can accurately represent the ambiguity in species tree root assignment for data sets where information is limited. Furthermore, application of STRIDE to outgroup-free inference of the origin of the eukaryotic tree resulted in a root probability distribution that provides additional support for leading hypotheses for the origin of the eukaryotes. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  11. Wood anatomy and physical and chemical properties of fast growing Athel tamarisk (Tamarix aphylla L.

    Directory of Open Access Journals (Sweden)

    Reza oladi

    2017-02-01

    Full Text Available Athel tamarisk (Tamarix aphylla is a fast growing, evergreen tree succeeding in the most soils and can tolerate the saline conditions. Despite its ecological importance and wide distribution in central and southern parts of Iran, wood properties of this species has little been concerned. However, the potential of this species in cellulosic industries of Middle East dry countries has recently been focused. Hence, to study wood anatomy and physical and chemical properties of Athel tamarisk, 3 stands were selected and felled from the Zabol region (Sistan and Baluchestan province. Wood anatomical features of this species were studied and listed according to the list of microscopic features for hardwood identification by IAWA Committee. In addition, lignin distribution in xylem was studied using fluorescence microscopy. Calculating fiber biometry features assessed that although fiber quality is not perfect but meets the standards of paper production, comparing other commercially used hardwoods in this industry. According to chemical composition analysis, cellulose content of this wood is rather low (39% which could be a result of large amount of thin-walled paranchyma cells in xylem. Lignin content is a bit higher than average hardwoods and this component is concentrated in vessels and fibers. Physical properties of studied wood samples (specific gravity and shrinkage values were in the range of other light-weight and fast growing hardwoods and thus this wood is expected to have similar end-use quality.

  12. Dust retaining properties of leaves of some tree species

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, M I

    1960-05-01

    A study was made in Tashkent, Russia of the dust-retaining power of leaves of several tree species. Investigations were made in a park where these tree species were growing in close proximity, exposed to the effects of dust from the main city street and from the highway passing through the park. Observations on the dust-retaining power of leaves were made mostly during the summer and fall months. The dust-retaining power of leaves of different tree species varied with the dust concentration in the air. In the summer and fall when rains are scarce a steady accumulation of dust was observed on the surface of the leaves. 1 table.

  13. Fast-growing Acer rubrum differs from slow-growing Quercus alba in leaf, xylem and hydraulic trait coordination responses to simulated acid rain.

    Science.gov (United States)

    Medeiros, Juliana S; Tomeo, Nicholas J; Hewins, Charlotte R; Rosenthal, David M

    2016-08-01

    We investigated the effects of historic soil chemistry changes associated with acid rain, i.e., reduced soil pH and a shift from nitrogen (N)- to phosphorus (P)-limitation, on the coordination of leaf water demand and xylem hydraulic supply traits in two co-occurring temperate tree species differing in growth rate. Using a full-factorial design (N × P × pH), we measured leaf nutrient content, water relations, leaf-level and canopy-level gas exchange, total biomass and allocation, as well as stem xylem anatomy and hydraulic function for greenhouse-grown saplings of fast-growing Acer rubrum (L.) and slow-growing Quercus alba (L.). We used principle component analysis to characterize trait coordination. We found that N-limitation, but not P-limitation, had a significant impact on plant water relations and hydraulic coordination of both species. Fast-growing A. rubrum made hydraulic adjustments in response to N-limitation, but trait coordination was variable within treatments and did not fully compensate for changing allocation across N-availability. For slow-growing Q. alba, N-limitation engendered more strict coordination of leaf and xylem traits, resulting in similar leaf water content and hydraulic function across all treatments. Finally, low pH reduced the propensity of both species to adjust leaf water relations and xylem anatomical traits in response to nutrient manipulations. Our data suggest that a shift from N- to P-limitation has had a negative impact on the water relations and hydraulic function of A. rubrum to a greater extent than for Q. alba We suggest that current expansion of A. rubrum populations could be tempered by acidic N-deposition, which may restrict it to more mesic microsites. The disruption of hydraulic acclimation and coordination at low pH is emphasized as an interesting area of future study. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Inverse modeling and animation of growing single-stemmed trees at interactive rates

    Science.gov (United States)

    S. Rudnick; L. Linsen; E.G. McPherson

    2007-01-01

    For city planning purposes, animations of growing trees of several species can be used to deduce which species may best fit a particular environment. The models used for the animation must conform to real measured data. We present an approach for inverse modeling to fit global growth parameters. The model comprises local production rules, which are iteratively and...

  15. Tree species effect on the redistribution of soil metals

    International Nuclear Information System (INIS)

    Mertens, Jan; Van Nevel, Lotte; De Schrijver, An; Piesschaert, Frederic; Oosterbaan, Anne; Tack, Filip M.G.; Verheyen, Kris

    2007-01-01

    Phytostabilization of metals using trees is often promoted although the influence of different tree species on the mobilization of metals is not yet clear. Soil and biomass were sampled 33 years after planting four tree species (Quercus robur, Fraxinus excelsior, Acer pseudoplatanus, Populus 'Robusta') in a plot experiment on dredged sediment. Poplar took up high amounts of Cd and Zn and this was associated with increased Cd and Zn concentrations in the upper soil layer. The other species contained normal concentrations of Cd, Cu, Cr, Pb and Zn in their tissues. Oak acidified the soil more than the other species and caused a decrease in the concentration of metals in the upper soil layer. The pH under poplar was lower than expected and associated with high carbon concentrations in the top soil. This might be assigned to retardation of the litter decomposition due to elevated Cd and Zn concentrations in the litter. - Trees (33-year-old) growing on polluted dredged sediment have influenced the metal concentration in the upper soil layer and there was a significant tree species effect

  16. Insight into the genetic components of community genetics: QTL mapping of insect association in a fast-growing forest tree.

    Directory of Open Access Journals (Sweden)

    Jennifer DeWoody

    Full Text Available Identifying genetic sequences underlying insect associations on forest trees will improve the understanding of community genetics on a broad scale. We tested for genomic regions associated with insects in hybrid poplar using quantitative trait loci (QTL analyses conducted on data from a common garden experiment. The F2 offspring of a hybrid poplar (Populus trichocarpa x P. deltoides cross were assessed for seven categories of insect leaf damage at two time points, June and August. Positive and negative correlations were detected among damage categories and between sampling times. For example, sap suckers on leaves in June were positively correlated with sap suckers on leaves (P<0.001 but negatively correlated with skeletonizer damage (P<0.01 in August. The seven forms of leaf damage were used as a proxy for seven functional groups of insect species. Significant variation in insect association occurred among the hybrid offspring, including transgressive segregation of susceptibility to damage. NMDS analyses revealed significant variation and modest broad-sense heritability in insect community structure among genets. QTL analyses identified 14 genomic regions across 9 linkage groups that correlated with insect association. We used three genomics tools to test for putative mechanisms underlying the QTL. First, shikimate-phenylpropanoid pathway genes co-located to 9 of the 13 QTL tested, consistent with the role of phenolic glycosides as defensive compounds. Second, two insect association QTL corresponded to genomic hotspots for leaf trait QTL as identified in previous studies, indicating that, in addition to biochemical attributes, leaf morphology may influence insect preference. Third, network analyses identified categories of gene models over-represented in QTL for certain damage types, providing direction for future functional studies. These results provide insight into the genetic components involved in insect community structure in a fast-growing

  17. Drivers of Tree Species Effects on Phosphorus and Cation Cycling in Plantations at La Selva Biological Station, Costa Rica

    Science.gov (United States)

    Russell, A. E.

    2014-12-01

    Fast-growing trees in secondary forests and plantations in the humid tropics play an important role in the atmospheric CO2 balance owing to their high rates of carbon sequestration. Because plants require nutrients to sustain high CO2 uptake, differences among tree species in traits related to nutrient uptake, retention and recycling could influence ecosystem-scale carbon cycling. A better understanding of the relationships among plant traits, nutrient and carbon cycling will thus improve ecosystem- to global scale modeling of effects of vegetation change on carbon cycling. In an experimental setting in which state factors were similar among four species of tropical trees situated on an Oxisol in replicated, 25-yr-old, mono-dominant plantations, I evaluated various drivers of aboveground storage of phosphorus (P) and cations, measuring nutrient fluxes in litterfall and fine-root growth and storage in biomass and soil to 1-m depth. Because fine roots increase the capacity to scavenge nutrients already on exchange sites within the soil environment, I hypothesized that P and cation uptake would be correlated directly with fine-root growth. The four tree species in this experiment, Hieronyma alchorneoides, Pentaclethra macroloba, Virola koschnyi, and Vochysia guatemalensis differed significantly in net cation uptake over the first 25 years of growth (P = 0.013, Ca; P >0.0001, Mg, Mn, K, Al, Fe, and Sr). For all cations, aboveground tree biomass was highly correlated with fine-root ingrowth length, with P values >0.0001 for all cations except Ca (P = 0.013). In contrast for P, differences among species were only marginally significant (P = 0.062). Similarly, P in aboveground tree biomass was marginally correlated with fine-root ingrowth (P = 0.068). Neither cation nor P uptake was correlated with measures of available P and cations, organic or total P in surface soil. For P, the less significant correlation with fine-root growth suggests that some other mechanism, such

  18. Glulam Properties of Fast-growing Species Using Mahogany Tannin Adhesive

    Directory of Open Access Journals (Sweden)

    Andi Sri Rahayu Diza Lestari

    2015-09-01

    Full Text Available Manufacturing glued laminated timber (glulam can help overcome the limited availability of large-sized timber, and the use of bio-adhesives may resolve environmental problems associated with synthetic adhesives containing high formaldehyde contents. Tannin adhesive is a bio-adhesive that can be used as alternative glue in the manufacture of glulam. The purpose of this study was to determine the physical and mechanical properties of glulam made with mahogany (Swietenia sp. tannin adhesive and wood from three fast-growing species, namely pine (Pinus merkusii, jabon (Anthocephalus cadamba, and sengon (Falcataria moluccana. Glulam (3 cm × 6 cm × 120 cm in thickness, width, and length, respectively was manufactured with three layers of lamina. The physical and mechanical properties of the glulams were tested based on relevant standards. The results showed that pine glulam fulfilled the standard for the modulus of rupture and modulus of elasticity, while sengon glulam met the standard for shear strength. In the delamination test, sengon glulam was resistant to immersion in cold water and hot water. All glulams had low formaldehyde emission levels and therefore fulfilled the standard requirements. The results showed that the tannin adhesive from mahogany bark was equal in quality to methylene diphenyl di-isocyanate for glulam manufacturing.

  19. Growth strategies of tropical tree species: disentangling light and size effects.

    Directory of Open Access Journals (Sweden)

    Nadja Rüger

    Full Text Available An understanding of the drivers of tree growth at the species level is required to predict likely changes of carbon stocks and biodiversity when environmental conditions change. Especially in species-rich tropical forests, it is largely unknown how species differ in their response of growth to resource availability and individual size. We use a hierarchical bayesian approach to quantify the impact of light availability and tree diameter on growth of 274 woody species in a 50-ha long-term forest census plot in Barro Colorado Island, Panama. Light reaching each individual tree was estimated from yearly vertical censuses of canopy density. The hierarchical bayesian approach allowed accounting for different sources of error, such as negative growth observations, and including rare species correctly weighted by their abundance. All species grew faster at higher light. Exponents of a power function relating growth to light were mostly between 0 and 1. This indicates that nearly all species exhibit a decelerating increase of growth with light. In contrast, estimated growth rates at standardized conditions (5 cm dbh, 5% light varied over a 9-fold range and reflect strong growth-strategy differentiation between the species. As a consequence, growth rankings of the species at low (2% and high light (20% were highly correlated. Rare species tended to grow faster and showed a greater sensitivity to light than abundant species. Overall, tree size was less important for growth than light and about half the species were predicted to grow faster in diameter when bigger or smaller, respectively. Together light availability and tree diameter only explained on average 12% of the variation in growth rates. Thus, other factors such as soil characteristics, herbivory, or pathogens may contribute considerably to shaping tree growth in the tropics.

  20. A Bayesian Supertree Model for Genome-Wide Species Tree Reconstruction

    Science.gov (United States)

    De Oliveira Martins, Leonardo; Mallo, Diego; Posada, David

    2016-01-01

    Current phylogenomic data sets highlight the need for species tree methods able to deal with several sources of gene tree/species tree incongruence. At the same time, we need to make most use of all available data. Most species tree methods deal with single processes of phylogenetic discordance, namely, gene duplication and loss, incomplete lineage sorting (ILS) or horizontal gene transfer. In this manuscript, we address the problem of species tree inference from multilocus, genome-wide data sets regardless of the presence of gene duplication and loss and ILS therefore without the need to identify orthologs or to use a single individual per species. We do this by extending the idea of Maximum Likelihood (ML) supertrees to a hierarchical Bayesian model where several sources of gene tree/species tree disagreement can be accounted for in a modular manner. We implemented this model in a computer program called guenomu whose inputs are posterior distributions of unrooted gene tree topologies for multiple gene families, and whose output is the posterior distribution of rooted species tree topologies. We conducted extensive simulations to evaluate the performance of our approach in comparison with other species tree approaches able to deal with more than one leaf from the same species. Our method ranked best under simulated data sets, in spite of ignoring branch lengths, and performed well on empirical data, as well as being fast enough to analyze relatively large data sets. Our Bayesian supertree method was also very successful in obtaining better estimates of gene trees, by reducing the uncertainty in their distributions. In addition, our results show that under complex simulation scenarios, gene tree parsimony is also a competitive approach once we consider its speed, in contrast to more sophisticated models. PMID:25281847

  1. A Bayesian Supertree Model for Genome-Wide Species Tree Reconstruction.

    Science.gov (United States)

    De Oliveira Martins, Leonardo; Mallo, Diego; Posada, David

    2016-05-01

    Current phylogenomic data sets highlight the need for species tree methods able to deal with several sources of gene tree/species tree incongruence. At the same time, we need to make most use of all available data. Most species tree methods deal with single processes of phylogenetic discordance, namely, gene duplication and loss, incomplete lineage sorting (ILS) or horizontal gene transfer. In this manuscript, we address the problem of species tree inference from multilocus, genome-wide data sets regardless of the presence of gene duplication and loss and ILS therefore without the need to identify orthologs or to use a single individual per species. We do this by extending the idea of Maximum Likelihood (ML) supertrees to a hierarchical Bayesian model where several sources of gene tree/species tree disagreement can be accounted for in a modular manner. We implemented this model in a computer program called guenomu whose inputs are posterior distributions of unrooted gene tree topologies for multiple gene families, and whose output is the posterior distribution of rooted species tree topologies. We conducted extensive simulations to evaluate the performance of our approach in comparison with other species tree approaches able to deal with more than one leaf from the same species. Our method ranked best under simulated data sets, in spite of ignoring branch lengths, and performed well on empirical data, as well as being fast enough to analyze relatively large data sets. Our Bayesian supertree method was also very successful in obtaining better estimates of gene trees, by reducing the uncertainty in their distributions. In addition, our results show that under complex simulation scenarios, gene tree parsimony is also a competitive approach once we consider its speed, in contrast to more sophisticated models. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society of Systematic Biologists.

  2. A Robust Productivity Model for Grapple Yarding in Fast-Growing Tree Plantations

    Directory of Open Access Journals (Sweden)

    Riaan Engelbrecht

    2017-10-01

    Full Text Available New techniques have recently appeared that can extend the advantages of grapple yarding to fast-growing plantations. The most promising technique consists of an excavator-base un-guyed yarder equipped with new radio-controlled grapple carriages, fed by another excavator stationed on the cut-over. This system is very productive, avoids in-stand traffic, and removes operators from positions of high risk. This paper presents the results of a long-term study conducted on 12 different teams equipped with the new technology, operating in the fast-growing black wattle (Acacia mangium Willd plantations of Sarawak, Malaysia. Data were collected continuously for almost 8 months and represented 555 shifts, or over 55,000 cycles—each recorded individually. Production, utilization, and machine availability were estimated, respectively at: 63 m3 per productive machine hour (excluding all delays, 63% and 93%. Regression analysis of experimental data yielded a strong productivity forecast model that was highly significant, accounted for 50% of the total variability in the dataset and was validated with a non-significant error estimated at less than 1%. The figures reported in this study are especially robust, because they were obtained from a long-term study that covered multiple teams and accumulated an exceptionally large number of observations.

  3. Phosphorus dynamics and limitation of fast- and slow-growing temperate seaweeds in Oslofjord, Norway

    DEFF Research Database (Denmark)

    Pedersen, Morten Foldager; Borum, Jens; Fotel, Frank Leck

    2010-01-01

    During coastal eutrophication, fast-growing, ephemeral macroalgae bloom at the expense of slow-growing, perennial macroalgae. This change in community composition has been explained by a differential ability to exploit and utilize inorganic nitrogen among macroalgae with different growth strategies......-growing algae (Ulva and Ceramium) took up dissolved inorganic P (DIP) much faster than thicker, slower growing species (belonging to Fucus, Ascophyllum and Laminaria) but also had much higher P-demands per unit biomass and time. DIP concentrations in the Oslofjord were low from April through August, and fast......-growing species were unable to meet their P-demand from uptake for several months during summer. Hence, Ceramium and Ulva were potentially P-limited during summer, whereas Ascophyllum and Laminaria were able to acquire sufficient external DIP to remain P-replete throughout the year. Storage of P prevented Fucus...

  4. Seasonal variation in radiocesium concentrations in three tree species

    International Nuclear Information System (INIS)

    Garten, C.R. Jr.; Briese, L.A.; Sharitz, R.R.; Gentry, J.B.

    1975-01-01

    Radiocesium concentrations in leaves and stems of black willow (Salix nigra), wax myrtle (Myrica cerifera), and tag alder (Alnus serrulata) trees inhabiting a floodplain contaminated by production-reactor effluents were measured over 1 year. In willow and myrtle trees, leaf radiocesium levels were highest in the spring and declined during the growing season; stem levels remained relatively unchanged or exhibited a slight increase. Seasonal changes in alder tree parts depended on the site examined. The relationship among component parts was essentially consistent across species and collecting sites in the summer. The radiocesium concentrations in order of rank were: roots greater than or equal to leaves greater than stems. Species differences in component-part radiocesium levels were dependent on the part sampled and the collecting site examined. Mean soil to plant-part concentration factors in summer ranged from 0.9 to 7.6, and species means across leaves, stems, and roots averaged 2.1, 3.8, and 6.2 for alder, willow, and myrtle trees, respectively

  5. Effects of tree species on soil properties in a forest of the Northeastern United States

    NARCIS (Netherlands)

    Dijkstra, F.A.

    2001-01-01

    Large differences in soil pH and available Ca in the surface soil exist among tree species growing in a mixed hardwood forest in northwestern Connecticut. The observed association between tree species and specific soil chemical properties within mixed-species stands implies that changes in

  6. Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis.

    Science.gov (United States)

    Brienen, Roel J W; Zuidema, Pieter A

    2005-11-01

    Many tropical regions show one distinct dry season. Often, this seasonality induces cambial dormancy of trees, particularly if these belong to deciduous species. This will often lead to the formation of annual rings. The aim of this study was to determine whether tree species in the Bolivian Amazon region form annual rings and to study the influence of the total amount and seasonal distribution of rainfall on diameter growth. Ring widths were measured on stem discs of a total of 154 trees belonging to six rain forest species. By correlating ring width and monthly rainfall data we proved the annual character of the tree rings for four of our study species. For two other species the annual character was proved by counting rings on trees of known age and by radiocarbon dating. The results of the climate-growth analysis show a positive relationship between tree growth and rainfall in certain periods of the year, indicating that rainfall plays a major role in tree growth. Three species showed a strong relationship with rainfall at the beginning of the rainy season, while one species is most sensitive to the rainfall at the end of the previous growing season. These results clearly demonstrate that tree ring analysis can be successfully applied in the tropics and that it is a promising method for various research disciplines.

  7. Different Patterns of Changes in the Dry Season Diameter at Breast Height of Dominant and Evergreen Tree Species in a Mature Subtropical Forest in South China

    Institute of Scientific and Technical Information of China (English)

    Jun-Hua Yan; Guo-Yi Zhou; De-Qiang Zhang; Xu-Li Tang; Xu Wang

    2006-01-01

    Information on changes in diameter at breast height (DBH) is important for net primary production (NPP)estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species,different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning (around 05:00 h) that decreases to a minimum by about 14:00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis (Hance) Hemsl. exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.

  8. The role of selected tree species in industrial sewage sludge/flotation tailing management.

    Science.gov (United States)

    Mleczek, Mirosław; Rutkowski, Paweł; Niedzielski, Przemysław; Goliński, Piotr; Gąsecka, Monika; Kozubik, Tomisław; Dąbrowski, Jędrzej; Budzyńska, Sylwia; Pakuła, Jarosław

    2016-11-01

    The aim of the study was to estimate the ability of ten tree and bush species to tolerate and accumulate Cd, Cu, Pb, Zn, and As species [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg(-1)) in a pot experiment. The premise being that it will then be possible to select the most promising tree/bush species, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested tree species were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg(-1) DW), where the dominant As species was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected tree species that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters.

  9. The invasive alien tree Falcataria moluccana: its impacts and management

    Science.gov (United States)

    Flint Hughes; Tracy Johnson; Amanda Uowolo

    2013-01-01

    Falcataria moluccana (Miq.) Barneby and Grimes is a large tree that has become invasive in forests and developed landscapes across many Pacific islands. A fast-growing nitrogenfixing species, it transforms invaded ecosystems by dramatically increasing nutrient inputs, suppressing native species and facilitating invasion by other weeds. Individuals rapidly reach heights...

  10. An overview of industrial tree plantation conflicts in the global South: conflicts, trends, and resistance struggles

    NARCIS (Netherlands)

    W. Overbeek (Wilfridus); M. Kröger (Markus); J. Gerber (Julien-François)

    2012-01-01

    markdownabstractOver the past two decades, industrial tree plantations (ITPs), typically large-scale, intensively managed, even-age monoculture plantations, mostly exotic trees like fast-growing eucalyptus, pine and acacia species, but also rubber and oil palm, all destined for industrial processe s

  11. A maximum pseudo-likelihood approach for estimating species trees under the coalescent model

    Directory of Open Access Journals (Sweden)

    Edwards Scott V

    2010-10-01

    Full Text Available Abstract Background Several phylogenetic approaches have been developed to estimate species trees from collections of gene trees. However, maximum likelihood approaches for estimating species trees under the coalescent model are limited. Although the likelihood of a species tree under the multispecies coalescent model has already been derived by Rannala and Yang, it can be shown that the maximum likelihood estimate (MLE of the species tree (topology, branch lengths, and population sizes from gene trees under this formula does not exist. In this paper, we develop a pseudo-likelihood function of the species tree to obtain maximum pseudo-likelihood estimates (MPE of species trees, with branch lengths of the species tree in coalescent units. Results We show that the MPE of the species tree is statistically consistent as the number M of genes goes to infinity. In addition, the probability that the MPE of the species tree matches the true species tree converges to 1 at rate O(M -1. The simulation results confirm that the maximum pseudo-likelihood approach is statistically consistent even when the species tree is in the anomaly zone. We applied our method, Maximum Pseudo-likelihood for Estimating Species Trees (MP-EST to a mammal dataset. The four major clades found in the MP-EST tree are consistent with those in the Bayesian concatenation tree. The bootstrap supports for the species tree estimated by the MP-EST method are more reasonable than the posterior probability supports given by the Bayesian concatenation method in reflecting the level of uncertainty in gene trees and controversies over the relationship of four major groups of placental mammals. Conclusions MP-EST can consistently estimate the topology and branch lengths (in coalescent units of the species tree. Although the pseudo-likelihood is derived from coalescent theory, and assumes no gene flow or horizontal gene transfer (HGT, the MP-EST method is robust to a small amount of HGT in the

  12. Genetic selection and improvement of hard wood tree species for fuelwood production on sodic soil with particular reference to Prosopis juliflora

    Energy Technology Data Exchange (ETDEWEB)

    Goel, V.L.; Behl, H.M. [National Botanical Research Inst., Lucknow (India). Dept. of Tree Biology

    2001-07-01

    This study is part of a research programme on selection and improvement of fast growing tree species suitable for wood fuel production on sodic wastelands (pH 8.6-10.5). Field trials of nine legumes (Acacia auriculiformis, A. nilotica, Albizia lebbeck, A. procera, Dalbergia sissoo, Leucaena leucocephala, Pongamia pinnata, Prosopis juliflora, Pithecellobium dulce) and three other tree species (Azadirachta indica, Eucalyptus tereticornis and Terminalai arjuna) were selected for this study. Prosopis juliflora was the most promising species in terms of its biomass productivity (68.7 t ha{sup -1}) and fuel value index (148.8) after 8-yr of growth. Acacia nilotica ranked second. Intra-specific variations were screened at provenance and individual tree level in order to improve fuelwood production potential of P. juliflora through selection and breeding. Successful populations (gene pools) and individuals (genotypes) were closed and conserved in clonal gardens to produce quality germplasm for plantations on sodic wastelands. Genetic testing, selection and multiplication of selected material are under progress. This will optimise gains in future afforestation programmes on sodic soils. (Author)

  13. Growth rates of important East African montane forest trees, with ...

    African Journals Online (AJOL)

    These trees showed growth rates at least twice as high as those of the primary species. Juniperus procera was found to be the fastest growing species in the cedar forest, underlining its success in forming dense stands after a fire. Only young Podocarpus latifolius showed a similar fast growth. Olea europaea ssp. cuspidata, ...

  14. Capturing characteristics of beryllium-7 in selected tree species

    International Nuclear Information System (INIS)

    Narazaki, Yukinori; Karube, Yoshiharu.

    1997-01-01

    With regard to 7 Be, a natural radioactive nuclide, the botanical capturing characteristics were compared between eight species of those trees which grow in a local district. The mechanism of such botanical capture by their leaves was discussed. The amounts of captured 7 Be were different by tree species. Higher radioactivities were found in the coniferous trees than in the broadleaf trees. The seasonal change of 7 Be radioactivity in leaves was significantly higher in winter and spring and lower in summer. Since airborne or fallout 7 Be particles stay on the upper face of leaves, the deposited amount depended on the surface area per weight of leaves particularly for evergreen trees. Because the 7 Be amount in leaves depended on the fallout capturing ability of leafs superficial skin as well as the cleaning effect of rain and the like, the radioactivity on the surface can change depending on the surface condition of leaves even in the case the levels of 7 Be fallout stayed the same. (author)

  15. "Growing trees backwards": Description of a stand reconstruction model

    Science.gov (United States)

    Jonathan D. Bakker; Andrew J. Sanchez Meador; Peter Z. Fule; David W. Huffman; Margaret M. Moore

    2008-01-01

    We describe an individual-tree model that uses contemporary measurements to "grow trees backward" and reconstruct past tree diameters and stand structure in ponderosa pine dominated stands of the Southwest. Model inputs are contemporary structural measurements of all snags, logs, stumps, and living trees, and radial growth measurements, if available. Key...

  16. Urban tree species show the same hydraulic response to vapor pressure deficit across varying tree size and environmental conditions.

    Directory of Open Access Journals (Sweden)

    Lixin Chen

    Full Text Available The functional convergence of tree transpiration has rarely been tested for tree species growing under urban conditions even though it is of significance to elucidate the relationship between functional convergence and species differences of urban trees for establishing sustainable urban forests in the context of forest water relations.We measured sap flux of four urban tree species including Cedrus deodara, Zelkova schneideriana, Euonymus bungeanus and Metasequoia glyptostroboides in an urban park by using thermal dissipation probes (TDP. The concurrent microclimate conditions and soil moisture content were also measured. Our objectives were to examine 1 the influence of tree species and size on transpiration, and 2 the hydraulic control of urban trees under different environmental conditions over the transpiration in response to VPD as represented by canopy conductance. The results showed that the functional convergence between tree diameter at breast height (DBH and tree canopy transpiration amount (E(c was not reliable to predict stand transpiration and there were species differences within same DBH class. Species differed in transpiration patterns to seasonal weather progression and soil water stress as a result of varied sensitivity to water availability. Species differences were also found in their potential maximum transpiration rate and reaction to light. However, a same theoretical hydraulic relationship between G(c at VPD = 1 kPa (G(cref and the G(c sensitivity to VPD (-dG(c/dlnVPD across studied species as well as under contrasting soil water and R(s conditions in the urban area.We concluded that urban trees show the same hydraulic regulation over response to VPD across varying tree size and environmental conditions and thus tree transpiration could be predicted with appropriate assessment of G(cref.

  17. Urban tree species show the same hydraulic response to vapor pressure deficit across varying tree size and environmental conditions.

    Science.gov (United States)

    Chen, Lixin; Zhang, Zhiqiang; Ewers, Brent E

    2012-01-01

    The functional convergence of tree transpiration has rarely been tested for tree species growing under urban conditions even though it is of significance to elucidate the relationship between functional convergence and species differences of urban trees for establishing sustainable urban forests in the context of forest water relations. We measured sap flux of four urban tree species including Cedrus deodara, Zelkova schneideriana, Euonymus bungeanus and Metasequoia glyptostroboides in an urban park by using thermal dissipation probes (TDP). The concurrent microclimate conditions and soil moisture content were also measured. Our objectives were to examine 1) the influence of tree species and size on transpiration, and 2) the hydraulic control of urban trees under different environmental conditions over the transpiration in response to VPD as represented by canopy conductance. The results showed that the functional convergence between tree diameter at breast height (DBH) and tree canopy transpiration amount (E(c)) was not reliable to predict stand transpiration and there were species differences within same DBH class. Species differed in transpiration patterns to seasonal weather progression and soil water stress as a result of varied sensitivity to water availability. Species differences were also found in their potential maximum transpiration rate and reaction to light. However, a same theoretical hydraulic relationship between G(c) at VPD = 1 kPa (G(cref)) and the G(c) sensitivity to VPD (-dG(c)/dlnVPD) across studied species as well as under contrasting soil water and R(s) conditions in the urban area. We concluded that urban trees show the same hydraulic regulation over response to VPD across varying tree size and environmental conditions and thus tree transpiration could be predicted with appropriate assessment of G(cref).

  18. New Insights on Wood Dimensional Stability Influenced by Secondary Metabolites: The Case of a Fast-Growing Tropical Species Bagassa guianensis Aubl.

    Directory of Open Access Journals (Sweden)

    Julie Bossu

    Full Text Available Challenging evaluation of tropical forest biodiversity requires the reporting of taxonomic diversity but also the systematic characterization of wood properties in order to discover new promising species for timber industry. Among wood properties, the dimensional stability is regarded as a major technological characteristic to validate whether a wood species is adapted to commercial uses. Cell structure and organization are known to influence the drying shrinkage making wood density and microfibrils angle markers of choice to predict wood dimensional stability. On the contrary the role of wood extractive content remains unclear. This work focuses on the fast-growing tropical species Bagassa guianensis and we report herein a correlation between heartwood drying shrinkage and extractive content. Chemical extractions and shrinkage experiments were performed on separate wood twin samples to better evaluate correctly how secondary metabolites influence the wood shrinkage behaviour. Extractive content were qualitatively and quantitatively analysed using HPLC and NMR spectroscopy. We found that B guianensis heartwood has a homogeneous low shrinkage along its radius that could not be explained only by its basic density. In fact the low drying shrinkage is correlated to the high extractive content and a corrected model to improve the prediction of wood dimensional stability is presented. Additionally NMR experiments conducted on sapwood and heartwood extracts demonstrate that secondary metabolites biosynthesis occurs in sapwood thus revealing B. guianensis as a Juglans-Type heartwood formation. This work demonstrates that B. guianensis, a fast-growing species associated with high durability and high dimensional stability, is a good candidate for lumber production and commercial purposes.

  19. Tree root intrusion in sewer systems: A review of extent and costs

    Science.gov (United States)

    T.B. Randrup; E.G. McPherson; L.R. Costello

    2001-01-01

    Interference between trees and sewer systems is likely to occur in old systems and in cracked pipes. Factors that contribute to damage include old pipes with joints, shallow pipes, small-dimension pipes, and fast-growing tree species. Because roots are reported to cause >50% of all sewer blockages, costs associated with root removal from sewers is substantial. In...

  20. Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species.

    Science.gov (United States)

    Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P

    2016-03-16

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. © 2016 The Author(s).

  1. Selective logging in tropical forests decreases the robustness of liana–tree interaction networks to the loss of host tree species

    Science.gov (United States)

    Magrach, Ainhoa; Senior, Rebecca A.; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F.; Santamaria, Luis; Edwards, David P.

    2016-01-01

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the ‘health’ and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana–tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of ‘extinction debt’. PMID:26936241

  2. N-fertilization has different effects on the growth, carbon and nitrogen physiology, and wood properties of slow- and fast-growing Populus species.

    Science.gov (United States)

    Li, Hong; Li, Mengchun; Luo, Jie; Cao, Xu; Qu, Long; Gai, Ying; Jiang, Xiangning; Liu, Tongxian; Bai, Hua; Janz, Dennis; Polle, Andrea; Peng, Changhui; Luo, Zhi-Bin

    2012-10-01

    To investigate how N-fertilization affects the growth, carbon and nitrogen (N) physiology, and wood properties of poplars with contrasting growth characteristics, slow-growing (Populus popularis, Pp) and fast-growing (P. alba×P. glandulosa, Pg) poplar saplings were exposed to different N levels. Above-ground biomass, leaf area, photosynthetic rates (A), instantaneous photosynthetic nitrogen use efficiency (PNUE (i)), chlorophyll and foliar sugar concentrations were higher in Pg than in Pp. Foliar nitrate reductase (NR) activities and root glutamate synthase (GOGAT) activities were higher in Pg than in Pp as were the N amount and NUE of new shoots. Lignin contents and calorific values of Pg wood were less than that of Pp wood. N-fertilization reduced root biomass of Pg more than of Pp, but increased leaf biomass, leaf area, A, and PNUE(i) of Pg more than of Pp. Among 13 genes involved in the transport of ammonium or nitrate or in N assimilation, transcripts showed more pronounced changes to N-fertilization in Pg than in Pp. Increases in NR activities and N contents due to N-fertilization were larger in Pg than in Pp. In both species, N-fertilization resulted in lower calorific values as well as shorter and wider vessel elements/fibres. These results suggest that growth, carbon and N physiology, and wood properties are more sensitive to increasing N availability in fast-growing poplars than in slow-growing ones, which is probably due to prioritized resource allocation to the leaves and accelerated N physiological processes in fast-growing poplars under higher N levels.

  3. Tree species Diversity in the Department of Forest Resources ...

    African Journals Online (AJOL)

    An inventory of trees (>10cm diameter at breast height (dbh)) growing within the premises (~1.2ha) of the Department of Forest Resources Management (DFRM), University of Ibadan, Nigeria, was conducted as a case study of the species quality (richness and diversity) and quantity (volume) found on the University campus.

  4. Effect of Tree-Fall Gaps on Fruit-Feeding Nymphalidae Assemblages in a Peruvian Rainforest

    OpenAIRE

    Pardonnet, Sylvia

    2010-01-01

    Tropical rainforests are among the most complex and diverse ecosystems, composed of a mosaic of shady understory under the closed canopy and tree-fall gaps of varying sizes and age. The light reaching the forest floor favors the recruitment of fast growing plant species and provide food resources for other animal species including butterflies. The Nymphalidae are the most species rich butterfly family in the tropics, and are ideal bioindicators. We investigated the effect of the tree-fall gap...

  5. Tree-growth analyses to estimate tree species' drought tolerance.

    Science.gov (United States)

    Eilmann, Britta; Rigling, Andreas

    2012-02-01

    Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.

  6. A Maze Game on Android Using Growing Tree Method

    Science.gov (United States)

    Hendrawan, Y. F.

    2018-01-01

    A maze is a type of puzzle games where a player moves in complex and branched passages to find a particular target or location. One method to create a maze is the Growing Tree method. The method creates a tree that has branches which are the paths of a maze. This research explored three types of Growing Tree method implementations for maze generation on Android mobile devices. The layouts produced could be played in first and third-person perspectives. The experiment results showed that it took 17.3 seconds on average to generate 20 cells x 20 cells dynamic maze layouts.

  7. Slow growth rates of Amazonian trees: Consequences for carbon cycling

    Science.gov (United States)

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B.; Selhorst, Diogo; Chambers, Jeffrey Q.; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-01-01

    Quantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only ≈1mm/year diameter increment, grow half as fast as those from areas with more seasonal rainfall to the east and west. Slow growth rates mean that trees can attain great ages; across our sites we estimate 17-50% of trees with diameter >10 cm have ages exceeding 300 years. Whereas a few emergent trees that make up a large portion of the biomass grow faster, small trees that are more abundant grow slowly and attain ages of hundreds of years. The mean age of carbon in living trees (60-110 years) is within the range of or slightly longer than the mean residence time calculated from C inventory divided by annual C allocation to wood growth (40-100 years). Faster C turnover is observed in stands with overall higher rates of diameter increment and a larger fraction of the biomass in large, fast-growing trees. As a consequence, forests can recover biomass relatively quickly after disturbance, whereas recovering species composition may take many centuries. Carbon cycle models that apply a single turnover time for carbon in forest biomass do not account for variations in life strategy and therefore may overestimate the carbon sequestration potential of Amazon forests. PMID:16339903

  8. Estimation of the yield of poplars in plantations of fast-growing species within current results

    Directory of Open Access Journals (Sweden)

    Martin Fajman

    2009-01-01

    Full Text Available Current results are presented of allometric yield estimates of the poplar short rotation coppice. According to a literature review it is obvious that yield estimates, based on measurable quantities of a growing stand, depend not only on the selected tree specie or its clone, but also on the site location. The Jap-105 poplar clone (P. nigra x P. maximowiczii allometric relations were analyzed by regression methods aimed at the creation of the yield estimation methodology at a testing site in Domanínek. Altogether, the twelve polynomial dependences of particular measured quantities approved the high empirical data conformity with the tested regression model (correlation index from 0.9033 to 0.9967. Within the forward stepwise regression, factors were selected, which explain best examined estimates of the total biomass DM; i.e. d.b.h. and stem height. Furthermore, the KESTEMONT’s (1971 mo­del was verified with a satisfying conformity as well. Approving presented yield estimation methods, the presented models will be checked in a large-scale field trial.

  9. Antimicrobial Screening of Some Exotic Tree Species of Rajasthan Desert

    OpenAIRE

    B.B.S. Kapoor* and Shelja Pandita

    2013-01-01

    Antimicrobial screening of ethyl ether and alcoholic extracts of leaves of four selected exotic tree species growing inRajasthan Desert was carried out. Colophospermum mopane, Holoptelea integrifolia, Kigelia pinnata andPutranjiva roxburghii showed positive reactions against bacterial pathogens i.e. Staphylococcus aureus, Escherichiacoli and a fungal pathogen Candida albicans.

  10. STANDING HERBAGE BIOMASS UNDER DIFFERENT TREE SPECIES DISPERSED IN PASTURES OF CATTLE FARMS

    Directory of Open Access Journals (Sweden)

    Humberto Esquivel-Mimenza

    2013-08-01

    Full Text Available The study conducted in a tropical dry ecosystem at Cañas, Guanacaste, Costa Rica (10o 11´ N and 84o15´W measure the standing herbage biomass (SHB availability and quality under six isolated tree species of different canopy architecture dispersed in active Brachiaria brizantha pastures and compare it to that growing at full sun light. Standing herbage biomass (HB harvesting and Photosynthetic active radiation (PAR readings were taken at three different periods in a paired sample scheme. Of the six tree species studied, Enterolobium cyclocarpum had the largest mean crown cover while Acrocomia aculeata had the smallest. Significant differences were observed between species (P = 0.0002 and seasons (P<0.008 for the percentage of PAR transmitted under the canopy but PAR levels obtained under all species were consistent throughout seasons since the interaction between species and season was not significantly different (P=0.98. Lower PAR readings (<50% were taken under the canopies E. cyclocarpum and Guazuma ulmifolia (21.7 and 33.7 % respectively. Standing herbage biomass (SHB harvested under the crown of isolated mature individual tree species was significantly lower (P<0.001 than in open pasture areas for all tree species except that of A. aculeate but SHB crude protein content, was higher underneath all tree canopies. It can conclude that light reduction caused by tree canopies reduces SHB availability and increases the quality underneath tree canopies compared to areas of full sun but these varies accordingly to tree species and seasons.

  11. Can tree species diversity be assessed with Landsat data in a temperate forest?

    Science.gov (United States)

    Arekhi, Maliheh; Yılmaz, Osman Yalçın; Yılmaz, Hatice; Akyüz, Yaşar Feyza

    2017-10-28

    investigated beta diversity were strongly related to the development stage of a number of sampling plots in the tree species basal area method. To obtain beta diversity, the tree basal area method indicates better result than the tree species number method at representing similarity of regions which are located close together. In conclusion, NDVI is helpful for estimating the alpha diversity of trees over large areas when the vegetation is at the maximum growing season. Beta diversity could be obtained with the spectral heterogeneity of Landsat data. Future tree diversity studies using remote sensing data should select data sets when vegetation is at the maximum growing season. Also, forest tree diversity investigations can be identified by using higher-resolution remote sensing data such as ESA Sentinel 2 data which is freely available since June 2015.

  12. Reconciliation with non-binary species trees.

    Science.gov (United States)

    Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton; Durand, Dannie

    2008-10-01

    Reconciliation extracts information from the topological incongruence between gene and species trees to infer duplications and losses in the history of a gene family. The inferred duplication-loss histories provide valuable information for a broad range of biological applications, including ortholog identification, estimating gene duplication times, and rooting and correcting gene trees. While reconciliation for binary trees is a tractable and well studied problem, there are no algorithms for reconciliation with non-binary species trees. Yet a striking proportion of species trees are non-binary. For example, 64% of branch points in the NCBI taxonomy have three or more children. When applied to non-binary species trees, current algorithms overestimate the number of duplications because they cannot distinguish between duplication and incomplete lineage sorting. We present the first algorithms for reconciling binary gene trees with non-binary species trees under a duplication-loss parsimony model. Our algorithms utilize an efficient mapping from gene to species trees to infer the minimum number of duplications in O(|V(G) | x (k(S) + h(S))) time, where |V(G)| is the number of nodes in the gene tree, h(S) is the height of the species tree and k(S) is the size of its largest polytomy. We present a dynamic programming algorithm which also minimizes the total number of losses. Although this algorithm is exponential in the size of the largest polytomy, it performs well in practice for polytomies with outdegree of 12 or less. We also present a heuristic which estimates the minimal number of losses in polynomial time. In empirical tests, this algorithm finds an optimal loss history 99% of the time. Our algorithms have been implemented in NOTUNG, a robust, production quality, tree-fitting program, which provides a graphical user interface for exploratory analysis and also supports automated, high-throughput analysis of large data sets.

  13. Rhizosphere soil microbial index of tree species in a coal mining ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, S.; Masto, R.E.; Ram, L.C.; Selvi, V.A.; Srivastava, N.K.; Tripathi, R.C.; George, J. [Central Institute of Mining & Fuel Research, Dhanbad (India)

    2009-09-15

    Microbial characterization of the tree rhizosphere provides important information relating to the screening of tree species for re-vegetation of degraded land. Rhizosphere soil samples collected from a few predominant tree species growing in the coal mining ecosystem of Dhanbad, India, were analyzed for soil organic carbon (SOC), mineralizable N, microbial biomass carbon (MBC), active microbial biomass carbon (AMBC), basal soil respiration (BSR), and soil enzyme activities (dehydrogenase, urease, catalase, phenol oxidase, and peroxidase). Principal component analysis was employed to derive a rhizosphere soil microbial index (RSMI) and accordingly, dehydrogenase, BSR/MBC, MBC/SOC, EC, phenol oxidase and AMBC were found to be the most critical properties. The observed values for the above properties were converted into a unitless score (0-1.00) and the scores were integrated into RSMI. The tree species could be arranged in decreasing order of the RSMI as: A. marmelos (0.718), A. indica (0.715), Bauhinia bauhinia (0.693), B. monosperma (0.611), E. jambolana (0.601), Moringa oleifera (0.565), Dalbergia sissoo (0.498), T indica (0.488), Morus alba (0.415), F religiosa (0.291), Eucalyptus sp. (0.232) and T grandis (0.181). It was concluded that tree species in coal mining areas had diverse effects on their respective rhizosphere microbial processes, which could directly or indirectly determine the survival and performance of the planted tree species in degraded coal mining areas. Tree species with higher RSMI values could be recommended for re-vegetation of degraded coal mining area.

  14. Modeling the effects of tree species and incubation temperature on soil's extracellular enzyme activity in 78-year-old tree plantations

    Science.gov (United States)

    Zhou, Xiaoqi; Wang, Shen S. J.; Chen, Chengrong

    2017-12-01

    Forest plantations have been widely used as an effective measure for increasing soil carbon (C), and nitrogen (N) stocks and soil enzyme activities play a key role in soil C and N losses during decomposition of soil organic matter. However, few studies have been carried out to elucidate the mechanisms behind the differences in soil C and N cycling by different tree species in response to climate warming. Here, we measured the responses of soil's extracellular enzyme activity (EEA) to a gradient of temperatures using incubation methods in 78-year-old forest plantations with different tree species. Based on a soil enzyme kinetics model, we established a new statistical model to investigate the effects of temperature and tree species on soil EEA. In addition, we established a tree species-enzyme-C/N model to investigate how temperature and tree species influence soil C/N contents over time without considering plant C inputs. These extracellular enzymes included C acquisition enzymes (β-glucosidase, BG), N acquisition enzymes (N-acetylglucosaminidase, NAG; leucine aminopeptidase, LAP) and phosphorus acquisition enzymes (acid phosphatases). The results showed that incubation temperature and tree species significantly influenced all soil EEA and Eucalyptus had 1.01-2.86 times higher soil EEA than coniferous tree species. Modeling showed that Eucalyptus had larger soil C losses but had 0.99-2.38 times longer soil C residence time than the coniferous tree species over time. The differences in the residual soil C and N contents between Eucalyptus and coniferous tree species, as well as between slash pine (Pinus elliottii Engelm. var. elliottii) and hoop pine (Araucaria cunninghamii Ait.), increase with time. On the other hand, the modeling results help explain why exotic slash pine can grow faster, as it has 1.22-1.38 times longer residual soil N residence time for LAP, which mediate soil N cycling in the long term, than native coniferous tree species like hoop pine and

  15. Ecology and Conservation of the Critically Endangered Tree Species Gymnocladus assamicus in Arunachal Pradesh, India

    International Nuclear Information System (INIS)

    Choudhury, B.I.; Khan, M.L.; Arunachalam, A.; Das, A.K.

    2007-01-01

    Gymnocladus assamicus is a critically endangered leguminous tree species endemic to Northeast India. Mature pods of the trees yield soap material and are collected by local people for domestic purposes and religious activities. G. assamicus grows on hill slopes and along banks of streams. Male and hermaphrodite flowers are borne by separate individual trees. Altogether 28 mature trees were documented from nine populations. Of these, very few regenerating trees were found. This species regenerates only through seeds. The major constraints to natural regeneration are over harvesting of mature fruits, habitat destruction, grazing, predation of seeds by scatter-hoarding animals, poor percentage of seed germination due to their hard-waxy seed coats, and the lack of seed dispersal. Effective conservation initiatives should emphasize sustainable harvesting of mature pods, awareness among local people, and preservation of surviving individuals of the species. Nonetheless, reintroduction of the species to suitable ecological habitats is also recommended.

  16. Modeling the effects of tree species and incubation temperature on soil's extracellular enzyme activity in 78-year-old tree plantations

    Directory of Open Access Journals (Sweden)

    X. Zhou

    2017-12-01

    Full Text Available Forest plantations have been widely used as an effective measure for increasing soil carbon (C, and nitrogen (N stocks and soil enzyme activities play a key role in soil C and N losses during decomposition of soil organic matter. However, few studies have been carried out to elucidate the mechanisms behind the differences in soil C and N cycling by different tree species in response to climate warming. Here, we measured the responses of soil's extracellular enzyme activity (EEA to a gradient of temperatures using incubation methods in 78-year-old forest plantations with different tree species. Based on a soil enzyme kinetics model, we established a new statistical model to investigate the effects of temperature and tree species on soil EEA. In addition, we established a tree species–enzyme–C∕N model to investigate how temperature and tree species influence soil C∕N contents over time without considering plant C inputs. These extracellular enzymes included C acquisition enzymes (β-glucosidase, BG, N acquisition enzymes (N-acetylglucosaminidase, NAG; leucine aminopeptidase, LAP and phosphorus acquisition enzymes (acid phosphatases. The results showed that incubation temperature and tree species significantly influenced all soil EEA and Eucalyptus had 1.01–2.86 times higher soil EEA than coniferous tree species. Modeling showed that Eucalyptus had larger soil C losses but had 0.99–2.38 times longer soil C residence time than the coniferous tree species over time. The differences in the residual soil C and N contents between Eucalyptus and coniferous tree species, as well as between slash pine (Pinus elliottii Engelm. var. elliottii and hoop pine (Araucaria cunninghamii Ait., increase with time. On the other hand, the modeling results help explain why exotic slash pine can grow faster, as it has 1.22–1.38 times longer residual soil N residence time for LAP, which mediate soil N cycling in the long term, than native

  17. Evaluation of some tree species for heavy metal biomonitoring and ...

    African Journals Online (AJOL)

    ajl yemi

    It is well established that trees help to reduce air pollution, and there is a growing impetus for green ... with the expansion of cities, increasing demand of energy ... In this study, four plant species were selected in Isfahan city. Leaves samples were collected in July 2009. Leaf samples were dried at 70°C to constant weight.

  18. Tree-growth analyses to estimate tree species' drought tolerance

    NARCIS (Netherlands)

    Eilmann, B.; Rigling, A.

    2012-01-01

    Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree

  19. Reconciliation of Gene and Species Trees

    Directory of Open Access Journals (Sweden)

    L. Y. Rusin

    2014-01-01

    Full Text Available The first part of the paper briefly overviews the problem of gene and species trees reconciliation with the focus on defining and algorithmic construction of the evolutionary scenario. Basic ideas are discussed for the aspects of mapping definitions, costs of the mapping and evolutionary scenario, imposing time scales on a scenario, incorporating horizontal gene transfers, binarization and reconciliation of polytomous trees, and construction of species trees and scenarios. The review does not intend to cover the vast diversity of literature published on these subjects. Instead, the authors strived to overview the problem of the evolutionary scenario as a central concept in many areas of evolutionary research. The second part provides detailed mathematical proofs for the solutions of two problems: (i inferring a gene evolution along a species tree accounting for various types of evolutionary events and (ii trees reconciliation into a single species tree when only gene duplications and losses are allowed. All proposed algorithms have a cubic time complexity and are mathematically proved to find exact solutions. Solving algorithms for problem (ii can be naturally extended to incorporate horizontal transfers, other evolutionary events, and time scales on the species tree.

  20. Long-term impacts of selective logging on two Amazonian tree species with contrasting ecological and reproductive characteristics: inferences from Eco-gene model simulations.

    Science.gov (United States)

    Vinson, C C; Kanashiro, M; Sebbenn, A M; Williams, T C R; Harris, S A; Boshier, D H

    2015-08-01

    The impact of logging and subsequent recovery after logging is predicted to vary depending on specific life history traits of the logged species. The Eco-gene simulation model was used to evaluate the long-term impacts of selective logging over 300 years on two contrasting Brazilian Amazon tree species, Dipteryx odorata and Jacaranda copaia. D. odorata (Leguminosae), a slow growing climax tree, occurs at very low densities, whereas J. copaia (Bignoniaceae) is a fast growing pioneer tree that occurs at high densities. Microsatellite multilocus genotypes of the pre-logging populations were used as data inputs for the Eco-gene model and post-logging genetic data was used to verify the output from the simulations. Overall, under current Brazilian forest management regulations, there were neither short nor long-term impacts on J. copaia. By contrast, D. odorata cannot be sustainably logged under current regulations, a sustainable scenario was achieved by increasing the minimum cutting diameter at breast height from 50 to 100 cm over 30-year logging cycles. Genetic parameters were only slightly affected by selective logging, with reductions in the numbers of alleles and single genotypes. In the short term, the loss of alleles seen in J. copaia simulations was the same as in real data, whereas fewer alleles were lost in D. odorata simulations than in the field. The different impacts and periods of recovery for each species support the idea that ecological and genetic information are essential at species, ecological guild or reproductive group levels to help derive sustainable management scenarios for tropical forests.

  1. Identifying the rooted species tree from the distribution of unrooted gene trees under the coalescent.

    Science.gov (United States)

    Allman, Elizabeth S; Degnan, James H; Rhodes, John A

    2011-06-01

    Gene trees are evolutionary trees representing the ancestry of genes sampled from multiple populations. Species trees represent populations of individuals-each with many genes-splitting into new populations or species. The coalescent process, which models ancestry of gene copies within populations, is often used to model the probability distribution of gene trees given a fixed species tree. This multispecies coalescent model provides a framework for phylogeneticists to infer species trees from gene trees using maximum likelihood or Bayesian approaches. Because the coalescent models a branching process over time, all trees are typically assumed to be rooted in this setting. Often, however, gene trees inferred by traditional phylogenetic methods are unrooted. We investigate probabilities of unrooted gene trees under the multispecies coalescent model. We show that when there are four species with one gene sampled per species, the distribution of unrooted gene tree topologies identifies the unrooted species tree topology and some, but not all, information in the species tree edges (branch lengths). The location of the root on the species tree is not identifiable in this situation. However, for 5 or more species with one gene sampled per species, we show that the distribution of unrooted gene tree topologies identifies the rooted species tree topology and all its internal branch lengths. The length of any pendant branch leading to a leaf of the species tree is also identifiable for any species from which more than one gene is sampled.

  2. "Growing trees backwards": Description of a stand reconstruction model (P-53)

    Science.gov (United States)

    Jonathan D. Bakker; Andrew J. Sanchez Meador; Peter Z. Fule; David W. Huffman; Margaret M. Moore

    2008-01-01

    We describe an individual-tree model that uses contemporary measurements to "grow trees backward" and reconstruct past tree diameters and stand structure in ponderosa pine dominated stands of the Southwest. Model inputs are contemporary structural measurements of all snags, logs, stumps, and living trees, and radial growth measurements, if available. Key...

  3. Methanol and isoprene emissions from the fast growing tropical pioneer species Vismia guianensis (Aubl. Pers. (Hypericaceae in the central Amazon forest

    Directory of Open Access Journals (Sweden)

    K. J. Jardine

    2016-05-01

    Full Text Available Isoprene (Is emissions by plants represent a loss of carbon and energy resources leading to the initial hypothesis that fast growing pioneer species in secondary tropical forests allocate carbon primarily to growth at the expense of isoprenoid defenses. In this study, we quantified leaf isoprene and methanol emissions from the abundant pantropical pioneer tree species Vismia guianensis and ambient isoprene concentrations above a diverse secondary forest in the central Amazon. As photosynthetically active radiation (PAR was varied (0 to 3000 µmol m−2 s−1 under standard leaf temperature (30 °C, isoprene emissions from V. guianensis increased without saturation up to 80 nmol m−2 s−1. A nonlinear increase in isoprene emissions with respect to net photosynthesis (Pn resulted in the fraction of Pn dedicated to isoprene emissions increasing with light intensity (up to 2 % of Pn. Emission responses to temperature under standard light conditions (PAR of 1000 µmol m−2 s−1 resulted in the classic uncoupling of isoprene emissions (Topt, iso > 40 °C from net photosynthesis (Topt, Pn = 30.0–32.5 °C with up to 7 % of Pn emitted as isoprene at 40 °C. Under standard environmental conditions of PAR and leaf temperature, young V. guianensis leaves showed high methanol emissions, low Pn, and low isoprene emissions. In contrast, mature leaves showed high Pn, high isoprene emissions, and low methanol emissions, highlighting the differential control of leaf phenology over methanol and isoprene emissions. High daytime ambient isoprene concentrations (11 ppbv were observed above a secondary Amazon rainforest, suggesting that isoprene emissions are common among neotropical pioneer species. The results are not consistent with the initial hypothesis and support a functional role of methanol during leaf expansion and the establishment of photosynthetic machinery and a protective role of isoprene for

  4. Are temperate canopy spiders tree-species specific?

    Science.gov (United States)

    Mupepele, Anne-Christine; Müller, Tobias; Dittrich, Marcus; Floren, Andreas

    2014-01-01

    Arboreal spiders in deciduous and coniferous trees were investigated on their distribution and diversity. Insecticidal knock-down was used to comprehensively sample spiders from 175 trees from 2001 to 2003 in the Białowieża forest and three remote forests in Poland. We identified 140 species from 9273 adult spiders. Spider communities were distinguished between deciduous and coniferous trees. The richest fauna was collected from Quercus where beta diversity was also highest. A tree-species-specific pattern was clearly observed for Alnus, Carpinus, Picea and Pinus trees and also for those tree species that were fogged in only four or three replicates, namely Betula and Populus. This hitherto unrecognised association was mainly due to the community composition of common species identified in a Dufrene-Legendre indicator species analysis. It was not caused by spatial or temporal autocorrelation. Explaining tree-species specificity for generalist predators like spiders is difficult and has to involve physical and ecological tree parameters like linkage with the abundance of prey species. However, neither did we find a consistent correlation of prey group abundances with spiders nor could differences in spider guild composition explain the observed pattern. Our results hint towards the importance of deterministic mechanisms structuring communities of generalist canopy spiders although the casual relationship is not yet understood.

  5. Complementary models of tree species-soil relationships in old-growth temperate forests

    Science.gov (United States)

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    context-dependent tree species-soil relationships occur simultaneouslyinold-grow the temperate forests, with context-dependent relationships strongest for organically cycled elements, and site-independent relationships strongest for weather able elements with in organic cycling phases. These models provide complementary explanations for patterns of nutrient accumulation and cycling in mixed species old-growth temperate forests.

  6. A new fast method for inferring multiple consensus trees using k-medoids.

    Science.gov (United States)

    Tahiri, Nadia; Willems, Matthieu; Makarenkov, Vladimir

    2018-04-05

    Gene trees carry important information about specific evolutionary patterns which characterize the evolution of the corresponding gene families. However, a reliable species consensus tree cannot be inferred from a multiple sequence alignment of a single gene family or from the concatenation of alignments corresponding to gene families having different evolutionary histories. These evolutionary histories can be quite different due to horizontal transfer events or to ancient gene duplications which cause the emergence of paralogs within a genome. Many methods have been proposed to infer a single consensus tree from a collection of gene trees. Still, the application of these tree merging methods can lead to the loss of specific evolutionary patterns which characterize some gene families or some groups of gene families. Thus, the problem of inferring multiple consensus trees from a given set of gene trees becomes relevant. We describe a new fast method for inferring multiple consensus trees from a given set of phylogenetic trees (i.e. additive trees or X-trees) defined on the same set of species (i.e. objects or taxa). The traditional consensus approach yields a single consensus tree. We use the popular k-medoids partitioning algorithm to divide a given set of trees into several clusters of trees. We propose novel versions of the well-known Silhouette and Caliński-Harabasz cluster validity indices that are adapted for tree clustering with k-medoids. The efficiency of the new method was assessed using both synthetic and real data, such as a well-known phylogenetic dataset consisting of 47 gene trees inferred for 14 archaeal organisms. The method described here allows inference of multiple consensus trees from a given set of gene trees. It can be used to identify groups of gene trees having similar intragroup and different intergroup evolutionary histories. The main advantage of our method is that it is much faster than the existing tree clustering approaches, while

  7. Long-term temporal changes in central European tree phenology (1946-2010) confirm the recent extension of growing seasons

    Science.gov (United States)

    Kolářová, Eva; Nekovář, Jiří; Adamík, Peter

    2014-10-01

    One of the ways to assess the impacts of climate change on plants is analysing their long-term phenological data. We studied phenological records of 18 common tree species and their 8 phenological phases, spanning 65 years (1946-2010) and covering the area of the Czech Republic. For each species and phenophase, we assessed the changes in its annual means (for detecting shifts in the timing of the event) and standard deviations (for detecting changes in duration of the phenophases). The prevailing pattern across tree species was that since around the year 1976, there has been a consistent advancement of the onset of spring phenophases (leaf unfolding and flowering) and subsequent acceleration of fruit ripening, and a delay of autumn phenophases (leaf colouring and leaf falling). The most considerable shifts in the timing of spring phenophases were displayed by early-successional short-lived tree species. The most pronounced temporal shifts were found for the beginning of seed ripening in conifers with an advancement in this phenophase of up to 2.2 days year-1 in Scots Pine ( Pinus sylvestris). With regards to the change in duration of the phenophases, no consistent patterns were revealed. The growing season has extended on average by 23.8 days during the last 35 years. The most considerable prolongation was found in Pedunculate Oak ( Quercus robur): 31.6 days (1976-2010). Extended growing season lengths do have the potential to increase growth and seed productivity, but unequal shifts among species might alter competitive relationships within ecosystems.

  8. Response of seedlings of different tree species to elevated C02 in Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    DAILi-min; JILan-zhu; WANGMiao; LIQiu-rong

    2003-01-01

    Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Lanx olgensis,Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 pmol· mol-1) and ambient CO2 (400μmol· mol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species.The broad-leaf tree species were more sensitive to the elevated CO2than conifer tree species. All seedlings showed a photo-synthetic acclimation to Iong-term elevated CO2.

  9. Object-based methods for individual tree identification and tree species classification from high-spatial resolution imagery

    Science.gov (United States)

    Wang, Le

    2003-10-01

    textures occurring due to branches and twigs. As a result from the inverse wavelet transform, the tree crown boundary is enhanced while the unwanted textures are suppressed. Based on the enhanced image, an improvement is achieved when applying the two-stage methods to a high resolution aerial photograph. To improve tree species classification, we develop a new method to choose the optimal scale parameter with the aid of Bhattacharya Distance (BD), a well-known index of class separability in traditional pixel-based classification. The optimal scale parameter is then fed in the process of a region-growing-based segmentation as a break-off value. Our object classification achieves a better accuracy in separating tree species when compared to the conventional Maximum Likelihood Classification (MLC). In summary, we develop two object-based methods for identifying individual trees and classifying tree species from high-spatial resolution imagery. Both methods achieve promising results and will promote integration of Remote Sensing and GIS in forest applications.

  10. Evaluation of Some Tree Species to Absorb Air Pollutants in Three Industrial Locations of South Bengaluru, India

    Directory of Open Access Journals (Sweden)

    Abida Begum

    2010-01-01

    Full Text Available With the fast growing and excessive increase in industrial projects in Bengaluru, the level of pollution is also increasing. Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. The study examined the air pollution tolerance indices (APTI of plant species around three industrial areas of south Bengaluru. The physiological and biochemical parameters, which are relative to leaf's water content (RWC, ascorbic acid content (AA, total leaf chlorophyll (TCh and leaf extract pH were used to compute the APTI values and three heavy metals were selected (cadmium, lead and zinc for analysis. The result shows that the most tolerant tree species with respect to ATPI and heavy metal concentration were Ficus religiosa, Azadirachta indica and Pongamia pinnata (L.. These plants can be considered as tolerant species in the industrial areas. The APTI values for remaining species are reported lower and are considered as sensitive species. Further studies on air pollution tolerance index with respect to three industrial areas of south Bengaluru indicated that the air pollution was maximum in Jigani industrial area and minimum in Electronic city.

  11. Tree species diversity mitigates disturbance impacts on the forest carbon cycle.

    Science.gov (United States)

    Silva Pedro, Mariana; Rammer, Werner; Seidl, Rupert

    2015-03-01

    Biodiversity fosters the functioning and stability of forest ecosystems and, consequently, the provision of crucial ecosystem services that support human well-being and quality of life. In particular, it has been suggested that tree species diversity buffers ecosystems against the impacts of disturbances, a relationship known as the "insurance hypothesis". Natural disturbances have increased across Europe in recent decades and climate change is expected to amplify the frequency and severity of disturbance events. In this context, mitigating disturbance impacts and increasing the resilience of forest ecosystems is of growing importance. We have tested how tree species diversity modulates the impact of disturbance on net primary production and the total carbon stored in living biomass for a temperate forest landscape in Central Europe. Using the simulation model iLand to study the effect of different disturbance regimes on landscapes with varying levels of tree species richness, we found that increasing diversity generally reduces the disturbance impact on carbon storage and uptake, but that this effect weakens or even reverses with successional development. Our simulations indicate a clear positive relationship between diversity and resilience, with more diverse systems experiencing lower disturbance-induced variability in their trajectories of ecosystem functioning. We found that positive effects of tree species diversity are mainly driven by an increase in functional diversity and a modulation of traits related to recolonization and resource usage. The results of our study suggest that increasing tree species diversity could mitigate the effects of intensifying disturbance regimes on ecosystem functioning and improve the robustness of forest carbon storage and the role of forests in climate change mitigation.

  12. A Pine Is a Pine and a Spruce Is a Spruce--The Effect of Tree Species and Stand Age on Epiphytic Lichen Communities.

    Science.gov (United States)

    Bäcklund, Sofia; Jönsson, Mari; Strengbom, Joachim; Frisch, Andreas; Thor, Göran

    2016-01-01

    With an increasing demand for forest-based products, there is a growing interest in introducing fast-growing non-native tree species in forest management. Such introductions often have unknown consequences for native forest biodiversity. In this study, we examine epiphytic lichen species richness and species composition on the trunks of non-native Pinus contorta and compare these to the native Pinus sylvestris and Picea abies in managed boreal forests in northern Sweden across a chronosequence of age classes. Overall, we recorded a total of 66,209 lichen occurrences belonging to 57 species in the 96 studied forest stands. We found no difference in species richness of lichens between stands of P. contorta and P. sylvestris, but stands of P. abies had higher total species richness. However, species richness of lichens in stands of P. abies decreased with increasing stand age, while no such age effect was detected for P. contorta and P. sylvestris. Lichen species composition progressively diverged with increasing stand age, and in 30-year-old stands all three tree species showed species-specific assemblages. Epiphytic lichen assemblages in stands of 30-year-old P. contorta were influenced by greater basal area, canopy closure, and average diameter at breast height, P. abies stands by higher branch density and canopy closure, and stands of P. sylvestris by greater bark crevice depth. Differences in lichen species richness and composition were mainly explained by canopy closure and habitat availability, and the greater canopy closure in mature P. abies stands promoted the colonization and growth of calicioid lichen species. Our results indicate that the non-native P. contorta have similar species richness as the native P. sylvestris. The main difference in lichen species richness and composition is between P. abies and Pinus spp. in managed forests of boreal Sweden.

  13. A Pine Is a Pine and a Spruce Is a Spruce--The Effect of Tree Species and Stand Age on Epiphytic Lichen Communities.

    Directory of Open Access Journals (Sweden)

    Sofia Bäcklund

    Full Text Available With an increasing demand for forest-based products, there is a growing interest in introducing fast-growing non-native tree species in forest management. Such introductions often have unknown consequences for native forest biodiversity. In this study, we examine epiphytic lichen species richness and species composition on the trunks of non-native Pinus contorta and compare these to the native Pinus sylvestris and Picea abies in managed boreal forests in northern Sweden across a chronosequence of age classes. Overall, we recorded a total of 66,209 lichen occurrences belonging to 57 species in the 96 studied forest stands. We found no difference in species richness of lichens between stands of P. contorta and P. sylvestris, but stands of P. abies had higher total species richness. However, species richness of lichens in stands of P. abies decreased with increasing stand age, while no such age effect was detected for P. contorta and P. sylvestris. Lichen species composition progressively diverged with increasing stand age, and in 30-year-old stands all three tree species showed species-specific assemblages. Epiphytic lichen assemblages in stands of 30-year-old P. contorta were influenced by greater basal area, canopy closure, and average diameter at breast height, P. abies stands by higher branch density and canopy closure, and stands of P. sylvestris by greater bark crevice depth. Differences in lichen species richness and composition were mainly explained by canopy closure and habitat availability, and the greater canopy closure in mature P. abies stands promoted the colonization and growth of calicioid lichen species. Our results indicate that the non-native P. contorta have similar species richness as the native P. sylvestris. The main difference in lichen species richness and composition is between P. abies and Pinus spp. in managed forests of boreal Sweden.

  14. Tree structural and species diversities in Okwangwo Forest, Cross ...

    African Journals Online (AJOL)

    Tree species were grouped into abundance classes. A total of 125 tree species belonging to 36 families and 96 genera were recorded in the area with Margaleffs index of species richness of 2.2754. Most (99) of the tree species encountered were threatened/endangered, 23 species were rare with only 3 tree species ...

  15. An estimate of the number of tropical tree species

    Science.gov (United States)

    Slik, J. W. Ferry; Arroyo-Rodríguez, Víctor; Aiba, Shin-Ichiro; Alvarez-Loayza, Patricia; Alves, Luciana F.; Ashton, Peter; Balvanera, Patricia; Bastian, Meredith L.; Bellingham, Peter J.; van den Berg, Eduardo; Bernacci, Luis; da Conceição Bispo, Polyanna; Blanc, Lilian; Böhning-Gaese, Katrin; Boeckx, Pascal; Bongers, Frans; Boyle, Brad; Bradford, Matt; Brearley, Francis Q.; Breuer-Ndoundou Hockemba, Mireille; Bunyavejchewin, Sarayudh; Calderado Leal Matos, Darley; Castillo-Santiago, Miguel; Catharino, Eduardo L. M.; Chai, Shauna-Lee; Chen, Yukai; Colwell, Robert K.; Chazdon, Robin L.; Clark, Connie; Clark, David B.; Clark, Deborah A.; Culmsee, Heike; Damas, Kipiro; Dattaraja, Handanakere S.; Dauby, Gilles; Davidar, Priya; DeWalt, Saara J.; Doucet, Jean-Louis; Duque, Alvaro; Durigan, Giselda; Eichhorn, Karl A. O.; Eisenlohr, Pedro V.; Eler, Eduardo; Ewango, Corneille; Farwig, Nina; Feeley, Kenneth J.; Ferreira, Leandro; Field, Richard; de Oliveira Filho, Ary T.; Fletcher, Christine; Forshed, Olle; Franco, Geraldo; Fredriksson, Gabriella; Gillespie, Thomas; Gillet, Jean-François; Amarnath, Giriraj; Griffith, Daniel M.; Grogan, James; Gunatilleke, Nimal; Harris, David; Harrison, Rhett; Hector, Andy; Homeier, Jürgen; Imai, Nobuo; Itoh, Akira; Jansen, Patrick A.; Joly, Carlos A.; de Jong, Bernardus H. J.; Kartawinata, Kuswata; Kearsley, Elizabeth; Kelly, Daniel L.; Kenfack, David; Kessler, Michael; Kitayama, Kanehiro; Kooyman, Robert; Larney, Eileen; Laumonier, Yves; Laurance, Susan; Laurance, William F.; Lawes, Michael J.; do Amaral, Ieda Leao; Letcher, Susan G.; Lindsell, Jeremy; Lu, Xinghui; Mansor, Asyraf; Marjokorpi, Antti; Martin, Emanuel H.; Meilby, Henrik; Melo, Felipe P. L.; Metcalfe, Daniel J.; Medjibe, Vincent P.; Metzger, Jean Paul; Millet, Jerome; Mohandass, D.; Montero, Juan C.; de Morisson Valeriano, Márcio; Mugerwa, Badru; Nagamasu, Hidetoshi; Nilus, Reuben; Ochoa-Gaona, Susana; Onrizal; Page, Navendu; Parolin, Pia; Parren, Marc; Parthasarathy, Narayanaswamy; Paudel, Ekananda; Permana, Andrea; Piedade, Maria T. F.; Pitman, Nigel C. A.; Poorter, Lourens; Poulsen, Axel D.; Poulsen, John; Powers, Jennifer; Prasad, Rama C.; Puyravaud, Jean-Philippe; Razafimahaimodison, Jean-Claude; Reitsma, Jan; dos Santos, João Roberto; Roberto Spironello, Wilson; Romero-Saltos, Hugo; Rovero, Francesco; Rozak, Andes Hamuraby; Ruokolainen, Kalle; Rutishauser, Ervan; Saiter, Felipe; Saner, Philippe; Santos, Braulio A.; Santos, Fernanda; Sarker, Swapan K.; Satdichanh, Manichanh; Schmitt, Christine B.; Schöngart, Jochen; Schulze, Mark; Suganuma, Marcio S.; Sheil, Douglas; da Silva Pinheiro, Eduardo; Sist, Plinio; Stevart, Tariq; Sukumar, Raman; Sun, I.-Fang; Sunderland, Terry; Suresh, H. S.; Suzuki, Eizi; Tabarelli, Marcelo; Tang, Jangwei; Targhetta, Natália; Theilade, Ida; Thomas, Duncan W.; Tchouto, Peguy; Hurtado, Johanna; Valencia, Renato; van Valkenburg, Johan L. C. H.; Van Do, Tran; Vasquez, Rodolfo; Verbeeck, Hans; Adekunle, Victor; Vieira, Simone A.; Webb, Campbell O.; Whitfeld, Timothy; Wich, Serge A.; Williams, John; Wittmann, Florian; Wöll, Hannsjoerg; Yang, Xiaobo; Adou Yao, C. Yves; Yap, Sandra L.; Yoneda, Tsuyoshi; Zahawi, Rakan A.; Zakaria, Rahmad; Zang, Runguo; de Assis, Rafael L.; Garcia Luize, Bruno; Venticinque, Eduardo M.

    2015-01-01

    The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼40,000 and ∼53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼19,000–25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼4,500–6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa. PMID:26034279

  16. STBase: one million species trees for comparative biology.

    Science.gov (United States)

    McMahon, Michelle M; Deepak, Akshay; Fernández-Baca, David; Boss, Darren; Sanderson, Michael J

    2015-01-01

    Comprehensively sampled phylogenetic trees provide the most compelling foundations for strong inferences in comparative evolutionary biology. Mismatches are common, however, between the taxa for which comparative data are available and the taxa sampled by published phylogenetic analyses. Moreover, many published phylogenies are gene trees, which cannot always be adapted immediately for species level comparisons because of discordance, gene duplication, and other confounding biological processes. A new database, STBase, lets comparative biologists quickly retrieve species level phylogenetic hypotheses in response to a query list of species names. The database consists of 1 million single- and multi-locus data sets, each with a confidence set of 1000 putative species trees, computed from GenBank sequence data for 413,000 eukaryotic taxa. Two bodies of theoretical work are leveraged to aid in the assembly of multi-locus concatenated data sets for species tree construction. First, multiply labeled gene trees are pruned to conflict-free singly-labeled species-level trees that can be combined between loci. Second, impacts of missing data in multi-locus data sets are ameliorated by assembling only decisive data sets. Data sets overlapping with the user's query are ranked using a scheme that depends on user-provided weights for tree quality and for taxonomic overlap of the tree with the query. Retrieval times are independent of the size of the database, typically a few seconds. Tree quality is assessed by a real-time evaluation of bootstrap support on just the overlapping subtree. Associated sequence alignments, tree files and metadata can be downloaded for subsequent analysis. STBase provides a tool for comparative biologists interested in exploiting the most relevant sequence data available for the taxa of interest. It may also serve as a prototype for future species tree oriented databases and as a resource for assembly of larger species phylogenies from precomputed

  17. STBase: one million species trees for comparative biology.

    Directory of Open Access Journals (Sweden)

    Michelle M McMahon

    Full Text Available Comprehensively sampled phylogenetic trees provide the most compelling foundations for strong inferences in comparative evolutionary biology. Mismatches are common, however, between the taxa for which comparative data are available and the taxa sampled by published phylogenetic analyses. Moreover, many published phylogenies are gene trees, which cannot always be adapted immediately for species level comparisons because of discordance, gene duplication, and other confounding biological processes. A new database, STBase, lets comparative biologists quickly retrieve species level phylogenetic hypotheses in response to a query list of species names. The database consists of 1 million single- and multi-locus data sets, each with a confidence set of 1000 putative species trees, computed from GenBank sequence data for 413,000 eukaryotic taxa. Two bodies of theoretical work are leveraged to aid in the assembly of multi-locus concatenated data sets for species tree construction. First, multiply labeled gene trees are pruned to conflict-free singly-labeled species-level trees that can be combined between loci. Second, impacts of missing data in multi-locus data sets are ameliorated by assembling only decisive data sets. Data sets overlapping with the user's query are ranked using a scheme that depends on user-provided weights for tree quality and for taxonomic overlap of the tree with the query. Retrieval times are independent of the size of the database, typically a few seconds. Tree quality is assessed by a real-time evaluation of bootstrap support on just the overlapping subtree. Associated sequence alignments, tree files and metadata can be downloaded for subsequent analysis. STBase provides a tool for comparative biologists interested in exploiting the most relevant sequence data available for the taxa of interest. It may also serve as a prototype for future species tree oriented databases and as a resource for assembly of larger species phylogenies

  18. A Pine Is a Pine and a Spruce Is a Spruce – The Effect of Tree Species and Stand Age on Epiphytic Lichen Communities

    Science.gov (United States)

    Bäcklund, Sofia; Jönsson, Mari; Strengbom, Joachim; Frisch, Andreas; Thor, Göran

    2016-01-01

    With an increasing demand for forest-based products, there is a growing interest in introducing fast-growing non-native tree species in forest management. Such introductions often have unknown consequences for native forest biodiversity. In this study, we examine epiphytic lichen species richness and species composition on the trunks of non-native Pinus contorta and compare these to the native Pinus sylvestris and Picea abies in managed boreal forests in northern Sweden across a chronosequence of age classes. Overall, we recorded a total of 66,209 lichen occurrences belonging to 57 species in the 96 studied forest stands. We found no difference in species richness of lichens between stands of P. contorta and P. sylvestris, but stands of P. abies had higher total species richness. However, species richness of lichens in stands of P. abies decreased with increasing stand age, while no such age effect was detected for P. contorta and P. sylvestris. Lichen species composition progressively diverged with increasing stand age, and in 30-year-old stands all three tree species showed species-specific assemblages. Epiphytic lichen assemblages in stands of 30-year-old P. contorta were influenced by greater basal area, canopy closure, and average diameter at breast height, P. abies stands by higher branch density and canopy closure, and stands of P. sylvestris by greater bark crevice depth. Differences in lichen species richness and composition were mainly explained by canopy closure and habitat availability, and the greater canopy closure in mature P. abies stands promoted the colonization and growth of calicioid lichen species. Our results indicate that the non-native P. contorta have similar species richness as the native P. sylvestris. The main difference in lichen species richness and composition is between P. abies and Pinus spp. in managed forests of boreal Sweden. PMID:26799558

  19. Photosynthetic temperature responses of tree species in Rwanda: evidence of pronounced negative effects of high temperature in montane rainforest climax species

    Science.gov (United States)

    Vårhammar, Angelica; Wallin, Göran; McLean, Christopher M.; Dusenge, Mirindi Eric; Medlyn, Belinda E.; Hasper, Thomas B.; Nsabimana, Donat; Uddling, Johan

    2015-04-01

    The sensitivity of photosynthetic metabolism to temperature has been identified as a key uncertainty for projecting the magnitude of the terrestrial feedback on future climate change. While temperature responses of photosynthetic capacities have been comparatively well investigated in temperate species, the responses of tropical tree species remain unexplored. We compared the responses of seedlings of native cold-adapted tropical montane rainforest tree species to exotic warm-adapted plantation species, all growing in an intermediate temperature common garden in Rwanda. Leaf gas exchange responses to CO2 at different temperatures (20 - 40 C) were used to assess the temperature responses of biochemical photosynthetic capacities. Analyses revealed a lower optimum temperature for photosynthetic electron transport rates than for Rubisco carboxylation rates, along with lower electron transport optima in the native cold-adapted than in the exotic warm-adapted species. The photosynthetic optimum temperatures were generally exceeded by daytime peak leaf temperatures, in particular in the native montane rainforest climax species. This study thus provides evidence of pronounced negative effects of high temperature in tropical trees and indicates high susceptibility of montane rainforest climax species to future global warming. (Reference: New Phytologist, in press)

  20. Rhizobia symbiosis of seven leguminous species growing along Xindian riverbank of Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Cheng-Tai Huang

    2018-01-01

    Full Text Available Legume-rhizobia symbioses of seven leguminous species growing along Xindian riverbank of Northern Taiwan were investigated in this study. These legumes form either determinate or indeterminate types of root nodules. The determinate nodules of Alysicarpus vaginalis, Desmodium. triflorum, D. heterophyllum, Sesbania cannabina and the indeterminate nodules of Mimosa pudica harbored bacteroids of morphological uniformity (length of 1-3 μm, while the indeterminate nodules of Crotalaria zanzibarica and Trifolium repens contained bacteroids of highly pleomorphism (size varying from 1 to 5 μm. The enclosed bacteria were isolated from respective nodules, and twenty slow-growing and nine fast-growing rhizobial isolates were recovered. The slow-growing isolates were classified to the genus Bradyrhizobium based on the 16S rRNA sequences, whereas the fast-growing rhizobia comprise four genera, Neorhizobium, Rhizobium, Cupriavidus and Paraburkholderia. Results of stable isotope analyses revealed that the seven leguminous species had similar and consistently negative δ15N values in leaves (mean of -1.2 ‰, whereas the values were positive (varying from 3.7 to 7.3 ‰ in the nodules. These values were significantly higher in the indeterminate nodules than those in the determinate ones. In addition, variations in the values of leaf δ13C (varying from -29 to -34‰ among the seven legumes were measured, indicating their photosynthetic water use efficiencies were different. This is the first field survey to report the rhizobial diversity and the nutrient relationships of sympatric legume in Taiwan.

  1. APPLICATION OF SOMACLONAL VARIABILITY TO PRODUCTION OF FAST-GROWING TREES AS A RAW MATERIAL FOR BIOFUEL

    Directory of Open Access Journals (Sweden)

    Voinikov V.K.

    2012-08-01

    Full Text Available Wood is one of the most widespread materials on the Earth. Wood raw materials may be used either to generate energy directly or to produce biofuel. The demand for sufficient amount of wood for these purposes necessitated establishment of arboreal plantations. Poplar тополь (Populus sp. is the most promising object to produce wood from plantations. In the last few years the Institute has been involved in the studies of potential of somaclonal variability in tissue cultivars to select plants with high growth indices. Berlin polar (P. × berolinensis, has been selected for this purpose, as its pyramid-shaped crown allows to place more plants on a plantation square area unit. It easily propagates by grafts and coppice shoots and is fairly resistant to leaf rust. Fast-growing trees may be acquired due to somaclonal variability and genetic transformation. In both cases an indispensable preliminary condition is a well-tested protocol of acquiring regenerates and their propagation in the cultivar of isolated tissues. Such a protocol has been worked out by now. It comprises the following phases: 1 isolation of stem tops in the first half of summer ant their sterilization; 2 cutting of explantates and their cultivation on the medium to induce regeneration; 3 propagation of regenerates on propagation medium; 4 elongation of regenerants; 5 rooting of regenerants; 6 acclimation and transfer of plants to the field for growth. At phases 3, 4 and 5 plants with desirable somaclonal changes are selected. Somaclonal varieties are selected on the basis of a large number of regenerants. For their further growth prior to planting on the Institute test site hydroponic units installed at the artificial climate station are used. This ensures equal conditions of nutrition and moisturizing for all the regenerants planted. Little plants cultivated in vitro, which are acquired at this stage of the work, will be further used for genetic transformation. A gene

  2. VISION AND STRATEGIC THINKING IN THE ROMANIAN FAST GROWING FIRMS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Nicolae BIBU

    2016-07-01

    Full Text Available The purpose of this paper is to present preliminary specific issues concerning the vision and the strategic thinking of the managers of Romanian fast growing firms in the years of rapid growth. This paper clarifies two research questions. (1 The first research question is what is the message of the manager's vision of the Romanian fast growing firms? Therefore, we must first verify if the managers of the Romanian fast growing firms have a concrete vision about the business they run and if so, what is the vision of the managers about the companies that they lead? (2 The second research question is what findings can be drawn about the role of strategic thinking of the managers in the management of the Romanian fast growing firms? The research that we have conducted is a qualitative research. The research method that we used is the interview. The interview is specific to qualitative research. Regarding the method of analysis that we used it is the content analysis. The research was conducted on a total of 17 Romanian fast growing firms that are located in Timiș County. The firms were identified based on a specific selection criteria set after a thorough review of the literature in the field. The 17 companies that we have analysed represent the foundation of 17 in-depth case studies, which we believe helped us to better understand what it means in the Romanian context to grow fast, through the entrepreneurs managers vision and strategic thinking. The results presented in this paper come to strengthen the results reached by other researchers in this field. The results present an image of the current Romanian context – about the role of strategic thinking of the entrepreneur manager in the management of Romanian fast growing firms. The paper presents a detailed analysis of managers' vision of the Romanian fast growing firms. The paper also presents findings about the role of strategic thinking in helping managers achieve rapid growth in the

  3. The Role of Native Tree Species on Leaf Breakdown Dynamics of the Invasive Tree of Heaven ( Ailanthus altissima) in an Urban Stream

    Science.gov (United States)

    Swan, C.; Healey, B.

    2005-05-01

    Anthropogenic disturbance of ecosystem processes is increasingly being explored in urban settings. One profound impact is the striking increase in the distribution of invasive plant species. For example, Tree of Heaven (Ailanthus altissima, TOH), introduced into the U.S. from Asia in 1784, is a successful colonist of recently deforested habitats. As a result, remnant patches in urban ecosystems have become overrun with this tree species, excluding native species via fast growth and allelopathy. While suffering from human-induced degradation, urban streams still support food webs that function to process riparian-derived organic matter (e.g., leaves, wood). The purpose of this study was to (1) estimate leaf litter breakdown of native tree leaves and those of TOH in an urban stream, (2) study the detritivore feeding rate of the same leaf species, and (3) determine if increasing native species richness of leaf litter can alter breakdown of TOH leaves. Field manipulations of leaf pack composition were done in a highly urbanized stream (>30% upstream urban land use) in Baltimore County, Maryland, USA. This was complimented by a series of laboratory feeding experiments employing similar leaf treatments and local shredding invertebrate taxa. Breakdown of TOH alone was extremely rapid, significantly exceeding that of all native tree species employed. Furthermore, mixing TOH with native tree species, red maple and white oak, substantially reduced TOH decay compared to decay of TOH alone. However, supporting laboratory studies showed that TOH was a preferred resource by shredding invertebrates over all native species. Subsequent analysis of the structural integrity of all leaf species revealed that TOH was the least resistant to force, possibly explaining the counterintuitive decrease of TOH decay in mixtures. We interpret this as meaning the stream invertebrates, while preferring to consume TOH, appeared not to influence TOH decay in mixtures with native species. Instead

  4. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    Science.gov (United States)

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment.

  5. Big data of tree species distributions

    DEFF Research Database (Denmark)

    Serra-Diaz, Josep M.; Enquist, Brian J.; Maitner, Brian

    2018-01-01

    are currently available in big databases, several challenges hamper their use, notably geolocation problems and taxonomic uncertainty. Further, we lack a complete picture of the data coverage and quality assessment for open/public databases of tree occurrences. Methods: We combined data from five major...... and data aggregation, especially from national forest inventory programs, to improve the current publicly available data.......Background: Trees play crucial roles in the biosphere and societies worldwide, with a total of 60,065 tree species currently identified. Increasingly, a large amount of data on tree species occurrences is being generated worldwide: from inventories to pressed plants. While many of these data...

  6. Coalescent-based species tree inference from gene tree topologies under incomplete lineage sorting by maximum likelihood.

    Science.gov (United States)

    Wu, Yufeng

    2012-03-01

    Incomplete lineage sorting can cause incongruence between the phylogenetic history of genes (the gene tree) and that of the species (the species tree), which can complicate the inference of phylogenies. In this article, I present a new coalescent-based algorithm for species tree inference with maximum likelihood. I first describe an improved method for computing the probability of a gene tree topology given a species tree, which is much faster than an existing algorithm by Degnan and Salter (2005). Based on this method, I develop a practical algorithm that takes a set of gene tree topologies and infers species trees with maximum likelihood. This algorithm searches for the best species tree by starting from initial species trees and performing heuristic search to obtain better trees with higher likelihood. This algorithm, called STELLS (which stands for Species Tree InfErence with Likelihood for Lineage Sorting), has been implemented in a program that is downloadable from the author's web page. The simulation results show that the STELLS algorithm is more accurate than an existing maximum likelihood method for many datasets, especially when there is noise in gene trees. I also show that the STELLS algorithm is efficient and can be applied to real biological datasets. © 2011 The Author. Evolution© 2011 The Society for the Study of Evolution.

  7. Effects of nurse trees, spacing, and tree species on biomass production in mixed forest plantations

    DEFF Research Database (Denmark)

    Nord-Larsen, Thomas; Meilby, Henrik

    2016-01-01

    Growing concern about increasing concentrations of greenhouse gases in the atmosphere, and resulting global climate change, has spurred a growing demand for renewable energy. In this study, we hypothesized that a nurse tree crop may provide additional early yields of biomass for fuel, while...... was in most cases reduced due to competition. However, provided timely thinning of nurse trees, the qualitative development of the trees will allow for long-term timber production....

  8. Minimum variance rooting of phylogenetic trees and implications for species tree reconstruction.

    Science.gov (United States)

    Mai, Uyen; Sayyari, Erfan; Mirarab, Siavash

    2017-01-01

    Phylogenetic trees inferred using commonly-used models of sequence evolution are unrooted, but the root position matters both for interpretation and downstream applications. This issue has been long recognized; however, whether the potential for discordance between the species tree and gene trees impacts methods of rooting a phylogenetic tree has not been extensively studied. In this paper, we introduce a new method of rooting a tree based on its branch length distribution; our method, which minimizes the variance of root to tip distances, is inspired by the traditional midpoint rerooting and is justified when deviations from the strict molecular clock are random. Like midpoint rerooting, the method can be implemented in a linear time algorithm. In extensive simulations that consider discordance between gene trees and the species tree, we show that the new method is more accurate than midpoint rerooting, but its relative accuracy compared to using outgroups to root gene trees depends on the size of the dataset and levels of deviations from the strict clock. We show high levels of error for all methods of rooting estimated gene trees due to factors that include effects of gene tree discordance, deviations from the clock, and gene tree estimation error. Our simulations, however, did not reveal significant differences between two equivalent methods for species tree estimation that use rooted and unrooted input, namely, STAR and NJst. Nevertheless, our results point to limitations of existing scalable rooting methods.

  9. Estimating phylogenetic relationships despite discordant gene trees across loci: the species tree of a diverse species group of feather mites (Acari: Proctophyllodidae).

    Science.gov (United States)

    Knowles, Lacey L; Klimov, Pavel B

    2011-11-01

    With the increased availability of multilocus sequence data, the lack of concordance of gene trees estimated for independent loci has focused attention on both the biological processes producing the discord and the methodologies used to estimate phylogenetic relationships. What has emerged is a suite of new analytical tools for phylogenetic inference--species tree approaches. In contrast to traditional phylogenetic methods that are stymied by the idiosyncrasies of gene trees, approaches for estimating species trees explicitly take into account the cause of discord among loci and, in the process, provides a direct estimate of phylogenetic history (i.e. the history of species divergence, not divergence of specific loci). We illustrate the utility of species tree estimates with an analysis of a diverse group of feather mites, the pinnatus species group (genus Proctophyllodes). Discord among four sequenced nuclear loci is consistent with theoretical expectations, given the short time separating speciation events (as evident by short internodes relative to terminal branch lengths in the trees). Nevertheless, many of the relationships are well resolved in a Bayesian estimate of the species tree; the analysis also highlights ambiguous aspects of the phylogeny that require additional loci. The broad utility of species tree approaches is discussed, and specifically, their application to groups with high speciation rates--a history of diversification with particular prevalence in host/parasite systems where species interactions can drive rapid diversification.

  10. Reliance on deep soil water in the tree species Argania spinosa.

    Science.gov (United States)

    Zunzunegui, M; Boutaleb, S; Díaz Barradas, M C; Esquivias, M P; Valera, J; Jáuregui, J; Tagma, T; Ain-Lhout, F

    2017-12-07

    In South-western Morocco, water scarcity and high temperature are the main factors determining species survival. Argania spinosa (L.) Skeels is a tree species, endemic to Morocco, which is suffering from ongoing habitat shrinkage. Argan trees play essential local ecological and economic roles: protecting soils from erosion, shading different types of crops, helping maintain soil fertility and, even more importantly, its seeds are used by the local population for oil production, with valuable nutritional, medicinal and cosmetic purposes. The main objective of this study was to identify the sources of water used by this species and to assess the effect of water availability on the photosynthetic rate and stem water potential in two populations: one growing on the coast and a second one 10 km inland. Stem water potential, photosynthetic rate and xylem water isotopic composition (δ18O) were seasonally monitored during 2 years. Trees from both populations showed a similar strategy in the use of the available water sources, which was strongly dependent on deep soil water throughout the year. Nevertheless, during the wet season or under low precipitation a more complex water uptake pattern was found with a mixture of water sources, including precipitation and soil at different depths. No evidence was found of the use of either groundwater or atmospheric water in this species. Despite the similar water-use strategy, the results indicate that Argania trees from the inland population explored deeper layers than coastal ones as suggested by more depleted δ18O values recorded in the inland trees and better photosynthetic performance, hence suggesting that the coastal population of A. spinosa could be subjected to higher stress. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Photosynthetic temperature responses of tree species in Rwanda: evidence of pronounced negative effects of high temperature in montane rainforest climax species.

    Science.gov (United States)

    Vårhammar, Angelica; Wallin, Göran; McLean, Christopher M; Dusenge, Mirindi Eric; Medlyn, Belinda E; Hasper, Thomas B; Nsabimana, Donat; Uddling, Johan

    2015-05-01

    The sensitivity of photosynthetic metabolism to temperature has been identified as a key uncertainty for projecting the magnitude of the terrestrial feedback on future climate change. While temperature responses of photosynthetic capacities have been comparatively well investigated in temperate species, the responses of tropical tree species remain unexplored. We compared the responses of seedlings of native cold-adapted tropical montane rainforest tree species with those of exotic warm-adapted plantation species, all growing in an intermediate temperature common garden in Rwanda. Leaf gas exchange responses to carbon dioxide (CO2 ) at different temperatures (20-40°C) were used to assess the temperature responses of biochemical photosynthetic capacities. Analyses revealed a lower optimum temperature for photosynthetic electron transport rates than for Rubisco carboxylation rates, along with lower electron transport optima in the native cold-adapted than in the exotic warm-adapted species. The photosynthetic optimum temperatures were generally exceeded by daytime peak leaf temperatures, in particular in the native montane rainforest climax species. This study thus provides evidence of pronounced negative effects of high temperature in tropical trees and indicates high susceptibility of montane rainforest climax species to future global warming. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  12. An aid in choosing the right tree to leave

    Science.gov (United States)

    C. Allen Bickford

    1953-01-01

    The successful forest manager has a number of well-stocked stands containing trees that are sound, useful, and fast-growing. Each stand and each tree is increasing in value fast enough that its rate of earning equals or exceeds the earnings from comparable investments.

  13. Species collapse via hybridization in Darwin's tree finches.

    Science.gov (United States)

    Kleindorfer, Sonia; O'Connor, Jody A; Dudaniec, Rachael Y; Myers, Steven A; Robertson, Jeremy; Sulloway, Frank J

    2014-03-01

    Species hybridization can lead to fitness costs, species collapse, and novel evolutionary trajectories in changing environments. Hybridization is predicted to be more common when environmental conditions change rapidly. Here, we test patterns of hybridization in three sympatric tree finch species (small tree finch Camarhynchus parvulus, medium tree finch Camarhynchus pauper, and large tree finch: Camarhynchus psittacula) that are currently recognized on Floreana Island, Galápagos Archipelago. Genetic analysis of microsatellite data from contemporary samples showed two genetic populations and one hybrid cluster in both 2005 and 2010; hybrid individuals were derived from genetic population 1 (small morph) and genetic population 2 (large morph). Females of the large and rare species were more likely to pair with males of the small common species. Finch populations differed in morphology in 1852-1906 compared with 2005/2010. An unsupervised clustering method showed (a) support for three morphological clusters in the historical tree finch sample (1852-1906), which is consistent with current species recognition; (b) support for two or three morphological clusters in 2005 with some (19%) hybridization; and (c) support for just two morphological clusters in 2010 with frequent (41%) hybridization. We discuss these findings in relation to species demarcations of Camarhynchus tree finches on Floreana Island.

  14. Pushing the pace of tree species migration.

    Directory of Open Access Journals (Sweden)

    Eli D Lazarus

    Full Text Available Plants and animals have responded to past climate changes by migrating with habitable environments, sometimes shifting the boundaries of their geographic ranges by tens of kilometers per year or more. Species migrating in response to present climate conditions, however, must contend with landscapes fragmented by anthropogenic disturbance. We consider this problem in the context of wind-dispersed tree species. Mechanisms of long-distance seed dispersal make these species capable of rapid migration rates. Models of species-front migration suggest that even tree species with the capacity for long-distance dispersal will be unable to keep pace with future spatial changes in temperature gradients, exclusive of habitat fragmentation effects. Here we present a numerical model that captures the salient dynamics of migration by long-distance dispersal for a generic tree species. We then use the model to explore the possible effects of assisted colonization within a fragmented landscape under a simulated tree-planting scheme. Our results suggest that an assisted-colonization program could accelerate species-front migration rates enough to match the speed of climate change, but such a program would involve an environmental-sustainability intervention at a massive scale.

  15. Mass Mortality Events in the NW Adriatic Sea: Phase Shift from Slow- to Fast-Growing Organisms.

    Directory of Open Access Journals (Sweden)

    Cristina Gioia Di Camillo

    Full Text Available Massive outbreaks are increasing all over the world, which are likely related to climate change. The North Adriatic Sea, a sub-basin of the Mediterranean Sea, is a shallow semi-closed sea receiving high nutrients inputs from important rivers. These inputs sustain the highest productive basin of the Mediterranean Sea. Moreover, this area shows a high number of endemisms probably due to the high diversity of environmental conditions and the conspicuous food availability. Here, we documented two massive mortalities (2009 and 2011 and the pattern of recovery of the affected biocoenoses in the next two years. Results show an impressive and fast shift of the benthic assemblage from a biocoenosis mainly composed of slow-growing and long-lived species to a biocoenosis dominated by fast-growing and short-lived species. The sponge Chondrosia reniformis, one of the key species of this assemblage, which had never been involved in previous massive mortality events in the Mediterranean Sea, reduced its coverage by 70%, and only few small specimens survived. All the damaged sponges, together with many associated organisms, were detached by rough-sea conditions, leaving large bare areas on the rocky wall. Almost three years after the disease, the survived specimens of C. reniformis did not increase significantly in size, while the bare areas were colonized by fast-growing species such as stoloniferans, hydrozoans, mussels, algae, serpulids and bryozoans. Cnidarians were more resilient than massive sponges since they quickly recovered in less than one month. In the study area, the last two outbreaks caused a reduction in the filtration efficiency of the local benthic assemblage by over 60%. The analysis of the times series of wave heights and temperature revealed that the conditions in summer 2011 were not so extreme as to justify severe mass mortality, suggesting the occurrence of other factors which triggered the disease. The long-term observations of a

  16. FAST-GROWING COMPANIES FROM TIMIS COUNTRY: DOES THE AGE MATTER?

    Directory of Open Access Journals (Sweden)

    ALB MARIA

    2015-03-01

    Full Text Available This paper examines the relation between the company’s age and its growth and analyses the influence of age on growth by studying a specific group of companies, namely fast-growing companies from the Timis County, Romania. We have studied the performance of the fast-growing companies in the period of 2010-2013 using the STATA IC 12 software application. A linear regression analysis model with two variables was used. The dependent variable used was the rapid growth of the company, measured by the growth rate of the turnover and the independent variable used was the age of the company, measured by the number of years. The model was tested using the number of employees as a control variable. This paper’s conclusion is in agreement with many other findings from the literature in this subject. The presented results show that the turnover growth rates in the Romanian fast-growing companies tend to drop from one year to another, as the companies grow older.

  17. An estimate of the number of tropical tree species

    DEFF Research Database (Denmark)

    Slik, J. W Ferry; Arroyo-Rodríguez, Víctor; Aiba, Shin Ichiro

    2015-01-01

    The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, ...

  18. An Estimate Of The Number Of Tropical Tree Species.

    OpenAIRE

    Slik, J W Ferry; Arroyo-Rodríguez, Víctor; Aiba, Shin-Ichiro; Alvarez-Loayza, Patricia; Alves, Luciana F; Ashton, Peter; Balvanera, Patricia; Bastian, Meredith L; Bellingham, Peter J; van den Berg, Eduardo; Bernacci, Luis; da Conceição Bispo, Polyanna; Blanc, Lilian; Böhning-Gaese, Katrin; Boeckx, Pascal

    2016-01-01

    The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between similar to 40,000 and similar to 53,000...

  19. Three-year study of fast-growing trees in degraded soils amended with composts: Effects on soil fertility and productivity.

    Science.gov (United States)

    Madejón, Paula; Alaejos, Joaquin; García-Álbala, José; Fernández, Manuel; Madejón, Engracia

    2016-03-15

    Currently, worries about the effects of intensive plantations on long-term nutrient supply and a loss of productivity have risen. In this study two composts were added to degraded soils where this type of intensive crops were growing, to avoid the soil fertility decrease and try to increase biomass production. For the experiment, two degraded soils in terms of low organic carbon content and low pH were selected in South-West Spain: La Rábida (RA) and Villablanca (VI) sites. Both study sites were divided into 24 plots. In RA, half of the plots were planted with Populus x canadensis "I-214"; the other half was planted with Eucalyptus globulus. At the VI site, half of the plots were planted with Paulownia fortunei, and the other plots were planted with Eucalyptus globulus. For each tree and site, three treatments were established (two organic composts and a control without compost), with four replications per treatment. The organic amendments were "alperujo" compost, AC, a solid by-product from the extraction of olive oil, and BC, biosolid compost. During the three years of experimentation, samples of soils and plants were analyzed for studying chemical and biochemical properties of soil, plant growth and plant nutritional status and biomass production. The composts increased total organic carbon, water-soluble carbon, nutrients and pH of soil only in the most acidic soil. Soil biochemical quality was calculated with the geometric mean of the enzymatic activities (Dehydrogenase, β-glucosidase, Phosphatase and Urease activities) determined in soils. The results showed a beneficial improvement in comparison with soils without compost. However, the best results were found in the growth and biomass production of the studied trees, especially in Eucalyptus. Nutritional levels of leaves of the trees were, in general, in the normal established range for each species, although no clear effect of the composts was observed. The results of this study justify the addition of

  20. Asymptotic Properties of the Number of Matching Coalescent Histories for Caterpillar-Like Families of Species Trees.

    Science.gov (United States)

    Disanto, Filippo; Rosenberg, Noah A

    2016-01-01

    Coalescent histories provide lists of species tree branches on which gene tree coalescences can take place, and their enumerative properties assist in understanding the computational complexity of calculations central in the study of gene trees and species trees. Here, we solve an enumerative problem left open by Rosenberg (IEEE/ACM Transactions on Computational Biology and Bioinformatics 10: 1253-1262, 2013) concerning the number of coalescent histories for gene trees and species trees with a matching labeled topology that belongs to a generic caterpillar-like family. By bringing a generating function approach to the study of coalescent histories, we prove that for any caterpillar-like family with seed tree t , the sequence (h n ) n ≥ 0 describing the number of matching coalescent histories of the n th tree of the family grows asymptotically as a constant multiple of the Catalan numbers. Thus, h n  ∼ β t c n , where the asymptotic constant β t > 0 depends on the shape of the seed tree t. The result extends a claim demonstrated only for seed trees with at most eight taxa to arbitrary seed trees, expanding the set of cases for which detailed enumerative properties of coalescent histories can be determined. We introduce a procedure that computes from t the constant β t as well as the algebraic expression for the generating function of the sequence (h n ) n ≥ 0 .

  1. DLRS: gene tree evolution in light of a species tree.

    Science.gov (United States)

    Sjöstrand, Joel; Sennblad, Bengt; Arvestad, Lars; Lagergren, Jens

    2012-11-15

    PrIME-DLRS (or colloquially: 'Delirious') is a phylogenetic software tool to simultaneously infer and reconcile a gene tree given a species tree. It accounts for duplication and loss events, a relaxed molecular clock and is intended for the study of homologous gene families, for example in a comparative genomics setting involving multiple species. PrIME-DLRS uses a Bayesian MCMC framework, where the input is a known species tree with divergence times and a multiple sequence alignment, and the output is a posterior distribution over gene trees and model parameters. PrIME-DLRS is available for Java SE 6+ under the New BSD License, and JAR files and source code can be downloaded from http://code.google.com/p/jprime/. There is also a slightly older C++ version available as a binary package for Ubuntu, with download instructions at http://prime.sbc.su.se. The C++ source code is available upon request. joel.sjostrand@scilifelab.se or jens.lagergren@scilifelab.se. PrIME-DLRS is based on a sound probabilistic model (Åkerborg et al., 2009) and has been thoroughly validated on synthetic and biological datasets (Supplementary Material online).

  2. Tree Species Identity Shapes Earthworm Communities

    DEFF Research Database (Denmark)

    Schelfhout, Stephanie; Mertens, Jan; Verheyen, Kris

    2017-01-01

    Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden...... of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer...

  3. Multiple-purpose trees for pastoral farming in New Zealand: with emphasis on tree legumes. [Lucerne Tree: Medick Tree

    Energy Technology Data Exchange (ETDEWEB)

    Davies, D J.G.; Macfarlane, R P

    1979-01-01

    The potential for soil conservation and agroforestry of several native and exotic legumes is discussed. Flowering period, chemical composition of leaves/pods, hardiness to frost and drought, timber value, forage potential for livestock and bees, ornamental value and other products are tabulated with information on up to 38 species. Two low-growing species that have proved useful for slope stabilization as well as forage are tree lucerne (Cytisus palmensis) and tree medick (Medicago arborea), the latter being shrubby and more suitable for cold districts. Gleditsia triacanthos is recommended as a shade and fodder tree for farm pasture.

  4. Tree Species Richness Promotes Invertebrate Herbivory on Congeneric Native and Exotic Tree Saplings in a Young Diversity Experiment.

    Directory of Open Access Journals (Sweden)

    Annika Wein

    Full Text Available Tree diversity in forests is an important driver of ecological processes including herbivory. Empirical evidence suggests both negative and positive effects of tree diversity on herbivory, which can be, respectively, attributed to associational resistance or associational susceptibility. Tree diversity experiments allow testing for associational effects, but evidence regarding which pattern predominates is mixed. Furthermore, it is unknown if herbivory on tree species of native vs. exotic origin is influenced by changing tree diversity in a similar way, or if exotic tree species escape natural enemies, resulting in lower damage that is unrelated to tree diversity. To address these questions, we established a young tree diversity experiment in temperate southwestern Germany that uses high planting density (49 trees per plot; plot size 13 m2. The species pool consists of six congeneric species pairs of European and North American origin (12 species in total planted in monocultures and mixtures (1, 2, 4, 6 species. We assessed leaf damage by leaf-chewing insects on more than 5,000 saplings of six broadleaved tree species. Plot-level tree species richness increased leaf damage, which more than doubled from monocultures to six-species mixtures, strongly supporting associational susceptibility. However, leaf damage among congeneric native and exotic species pairs was similar. There were marked differences in patterns of leaf damage across tree genera, and only the genera likely having a predominately generalist herbivore community showed associational susceptibility, irrespective of the geographical origin of a tree species. In conclusion, an increase in tree species richness in young temperate forests may result in associational susceptibility to feeding by generalist herbivores.

  5. Characterizing the growth responses of three co-occurring northern conifer tree species to climate variation across a range of conditions

    Energy Technology Data Exchange (ETDEWEB)

    Green, S.; Miyamoto, Y. [Northern British Columbia Univ., Prince George, BC (Canada). Ecosystem Science and Management Program

    2006-07-01

    Climate is the key factor affecting tree growth. Trees regularly adapt to changing environmental conditions. Adjusting forest policies and practices under changing environments necessitates an understanding of species-specific tree responses to climate change. This paper discussed a study that examined the responses of 3 northern conifer tree species, notably the lodgepole pine, subalpine fir, and interior spruce. The purpose of the study was to characterize the climate sensitivities of each species growing under various environmental conditions, represented by mean annual temperatures and mean annual precipitations. The paper provided background information on climate change and tree species and discussed the objectives and implications of the study. Study methods were presented in detail and a geographical map showing the eight sampling sites located in central British Columbia and Yukon was also provided. Last, the paper provided the preliminary results and conclusions. It was found that the impacts of changing seasonal climates on tree growth will be species and site-specific. However, the magnitude of these differences were not completely analysed so that the impacts may be similar or significantly different among species or sites. 15 refs., 4 figs.

  6. Occurrence of leguminous trees

    Energy Technology Data Exchange (ETDEWEB)

    Kirkbride, J.H.; Arkcoll, D.B.A.; Turnbull, J.W.; Magalhaes, L.M.S.; Fernandes, N.P.

    1984-01-01

    Five papers from the symposium are presented. Kirkbride, J.H. Jr.; Legumes of the cerrado. pp 23-46 (Refs. 55) A review is given. Some 548 legume species in 59 genera are listed that have been reported from cerrado vegetation. Felker, P.; Legume trees in semi-arid and arid areas. pp 47-59 (Refs. 41) A review is given of worldwide research activities. Arkcoll, D.B.; A comparison of some fast growing species suitable for woodlots in the wet tropics. pp 61-68 (Refs. 9) Studies are described near Manaus on intensive silviculture (for fuelwood production) of Eucalyptus deglupta, Cedrelinga catanaeformis (catenaeformis), Jacaranda copaia, and Inga edulis. Turnbull, J.W.; Six phyllodinous Acacia species for planting in the humid tropical lowlands. pp 69-73 (Refs. 14) Distribution, ecology, growth, and utilization are described for A. auriculiformis, A. mangium, A. aulacocarpa, A. crassicarpa, A. cincinnata, and A. polystachya. Magalhaes, L.M.S., Fernandes, N.P.; Experimental stands of leguminous trees in the Manaus region. pp 75-79 (Refs. 8) Performance up to age 20 yr of Cedrelinga catenaeformis, Dalbergia nigra, Dinizia excelsa, Dipteryx odorata, Dipteryx sp., Diplotropis sp., Eperua bijuga, Pithecellobium racemosum, Vouacapoua pallidior, and Hymenaea sp. is described.

  7. Are Mixed Tropical Tree Plantations More Resistant to Drought than Monocultures?

    Directory of Open Access Journals (Sweden)

    Norbert Kunert

    2015-06-01

    Full Text Available Tropical tree plantations usually consist of a single exotic fast growing species, but recent research describes positive effects on ecosystem functions from mixed tropical tree plantations. In this review, we present the current knowledge of drought resistance of tropical mixed species plantations and summarize preliminary evidence from a tree biodiversity experiment in Panama. Converting mono-specific stands into mixed ones may improve stand stability and might reduce increasing abiotic and biotic disturbances due to climate change. However, little is known about the extent to which tropical tree species or tropical tree communities can resist increasing disturbances in the short term, e.g., water limitations due to increasing dry season intensity or length, or about their resilience after such disturbances and their capacity to adapt to changing conditions in the long term. Studies relating drought resistance and resilience to community diversity are missing. Further, we highlight the urgent need for a multifactorial manipulative throughfall reduction experiment in tropical environments. The outcome of such studies would greatly assist the forestry sector in tropical regions to maintain highly productive and ecologically sound forest plantations in a changing climate.

  8. CO2 enrichment alters diurnal stem radius fluctuations of 36-yr-old Larix decidua growing at the alpine tree line.

    Science.gov (United States)

    Dawes, Melissa A; Zweifel, Roman; Dawes, Nicholas; Rixen, Christian; Hagedorn, Frank

    2014-06-01

    To understand how trees at high elevations might use water differently in the future, we investigated the effects of CO2 enrichment and soil warming (separately and combined) on the water relations of Larix decidua growing at the tree line in the Swiss Alps. We assessed diurnal stem radius fluctuations using point dendrometers and applied a hydraulic plant model using microclimate and soil water potential data as inputs. Trees exposed to CO2 enrichment for 9 yr showed smaller diurnal stem radius contractions (by 46 ± 16%) and expansions (42 ± 16%) compared with trees exposed to ambient CO2 . Additionally, there was a delay in the timing of daily maximum (40 ± 12 min) and minimum (63 ± 14 min) radius values for trees growing under elevated CO2 . Parameters optimized with the hydraulic model suggested that CO2 -enriched trees had an increased flow resistance between the xylem and bark, representing a more buffered water supply system. Soil warming did not alter diurnal fluctuation dynamics or the CO2 response. Elevated CO2 altered the hydraulic water flow and storage system within L. decidua trees, which might have contributed to enhanced growth during 9 yr of CO2 enrichment and could ultimately influence the future competitive ability of this key tree-line species. © 2014 WSL Institute for Snow and Avalanche Research - SLF. New Phytologist © 2014 New Phytologist Trust.

  9. An innovative apparatus provided with a cutting auger for producing short logs for biomass energy from fast-growing tree species

    Energy Technology Data Exchange (ETDEWEB)

    Colorio, G.; Tomasone, R.; Cedrola, C.; Pagano, M.; Pochi, D.; Fanigliulo, R.; Sperandio, G. [Council for Research in Agriculture, Agricultural Engineering Research Unit, Rome (Italy)

    2010-07-01

    This paper reported on a new cutting mechanism that cuts fresh wood into small pieces instead of wood chips in order to avoid the problem of fermentation that occurs in storage. The prototype cutting device performs a gradual and oblique cut. It consists of a large auger in which a knife is inserted on the outer edge of the helicoid. Tree trunks up to 20 cm in diameter are fed perpendicularly into the machine and are pushed along the axis where slices are cut off against a fixed sharp-edged counter blade. The cylinder enclosing the auger is the main frame of the machine, and is closed at one end, where a heavy flywheel delivers the energy coming from the tractor's power take-off (PTO). The wood pieces ranging in length from 4 to 19 cm exit through the opposite end. The auger is 700 mm in diameter with a 300 mm pitch spacing. The logs are pushed into the machine by counter-rotating rollers placed in the feed funnel. Tests were conducted to determine the operative performance and power requirements of the machine. The cutting method requires less power compared to wood chipping machines. Work capacity is greater when producing slices instead of chips and the system produces less noise and fewer vibrations. The auger reaches a constant velocity of 200 RPM and can easily cut fresh wood of different species.

  10. Determining the annual periodicity of growth rings in seven tree species of a tropical moist forest in Santa Cruz, Bolivia

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, L.; Villalba, R.; Pena-Claros, M.

    2012-07-01

    To determine the annual periodicity of growth rings in seven tree species from a tropical moist forest in Santa Cruz, Bolivia, a fire scar was used as a marker point to verify the annual nature of tree rings. The number of tree rings formed between the 1995 fire scar and the collection of the cross sections in 2002 was visually identified. The seven species showed annual growth rings. In most cases, boundaries between rings were marked by the presence of marginal parenchyma and wall-thick ed fibers formed at the end of the growing season. Growth lenses and false rings were recorded in some species. Tree rings can be carefully used in Santa Cruz forests to determine rates of growth. This information is crucial for defining forest management practices in tropical regions. (Author) 21 refs.

  11. Integration of biotechnology, visualisation technology and robot technology for automated mass propagation af elite trees

    DEFF Research Database (Denmark)

    Find, Jens

    for the production of Christmas trees and Sitka spruce has gained renewed interest as a fast growing species for the production biofuels. These species are used as model systems for the development of automated plant production based on robot and visualisation technology. The commercial aspect of the project aims at......: 1) the market for cloned elite plants in the forestry sector and 2) the market for robot technology in the production of plants for the forestry sector....

  12. Fast-slow continuum and reproductive strategies structure plant life-history variation worldwide.

    Science.gov (United States)

    Salguero-Gómez, Roberto; Jones, Owen R; Jongejans, Eelke; Blomberg, Simon P; Hodgson, David J; Mbeau-Ache, Cyril; Zuidema, Pieter A; de Kroon, Hans; Buckley, Yvonne M

    2016-01-05

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous variation in life history are poorly understood. We use demographic data from 418 plant species in the wild, from annual herbs to supercentennial trees, to examine how growth form, habitat, and phylogenetic relationships structure plant life histories and to develop a framework to predict population performance. We show that 55% of the variation in plant life-history strategies is adequately characterized using two independent axes: the fast-slow continuum, including fast-growing, short-lived plant species at one end and slow-growing, long-lived species at the other, and a reproductive strategy axis, with highly reproductive, iteroparous species at one extreme and poorly reproductive, semelparous plants with frequent shrinkage at the other. Our findings remain consistent across major habitats and are minimally affected by plant growth form and phylogenetic ancestry, suggesting that the relative independence of the fast-slow and reproduction strategy axes is general in the plant kingdom. Our findings have similarities with how life-history strategies are structured in mammals, birds, and reptiles. The position of plant species populations in the 2D space produced by both axes predicts their rate of recovery from disturbances and population growth rate. This life-history framework may complement trait-based frameworks on leaf and wood economics; together these frameworks may allow prediction of responses of plants to anthropogenic disturbances and changing environments.

  13. Photosynthetic responses to understory shade and elevated carbon dioxide concentration in 4 northern hardwood tree species

    International Nuclear Information System (INIS)

    Sefcik, L.T.; Zak, D.R.; Ellsworth, D.S.

    2006-01-01

    Stimulation of photosynthesis in response to elevated carbon dioxide (CO 2 ) varies among tree species and species groups. In this study, seedling responses to elevated atmospheric carbon dioxide (CO 2 ) concentrations and solar irradiance over 2 growing seasons were investigated for shade tolerant Acer saccharum Marsh.; Fagus grandifolia J.F. Ehrh; and shade-intolerant Prunus serotina. Seedlings were exposed to a combination of elevated and ambient concentrations of CO 2 and understory shade in open-top chambers placed in a forest understory. It was observed that the elevated CO 2 treatment increased mean light-saturated net photosynthetic rates by 63 per cent in the shade-tolerant species and 67 per cent in the shade-intolerant species. When measured at the elevated CO 2 , long-term enhancement of photosynthesis was 10 per cent lower than the instantaneous enhancement observed in ambient-CO 2 -grown plants. As the growth irradiance increased, proportional enhancement due to elevated CO 2 decreased from 97 per cent for plants grown in deep shade to 47 per cent for plants grown in moderate shade. Results indicated that in nitrogen (N) limited northern temperate forests, trees grown in deep shade may display greater photosynthetic gains from a CO 2 enriched atmosphere than trees growing in more moderate shade, due to greater down-regulation. It was concluded that if elevated CO 2 levels promote the survival of shade-intolerant species in dim understory light, the future composition and dynamics of successional forest communities may be altered. 70 refs., 2 tabs., 3 figs

  14. Tree species effect on the redistribution of soil metals

    NARCIS (Netherlands)

    Mertens, J.; Nevel, Van L.; Schrijver, De A.; Piesschaert, F.; Oosterbaan, A.; Tack, F.M.G.; Verheyen, K.

    2007-01-01

    Phytostabilization of metals using trees is often promoted although the influence of different tree species on the mobilization of metals is not yet clear. Soil and biomass were sampled 33 years after planting four tree species (Quercus robur, Fraxinus excelsior, Acer pseudoplatanus, Populus

  15. Flavonoid supplementation affects the expression of genes involved in cell wall formation and lignification metabolism and increases sugar content and saccharification in the fast-growing eucalyptus hybrid E. urophylla x E. grandis.

    Science.gov (United States)

    Lepikson-Neto, Jorge; Nascimento, Leandro C; Salazar, Marcela M; Camargo, Eduardo L O; Cairo, João P F; Teixeira, Paulo J; Marques, Wesley L; Squina, Fabio M; Mieczkowski, Piotr; Deckmann, Ana C; Pereira, Gonçalo A G

    2014-11-19

    Eucalyptus species are the most widely planted hardwood species in the world and are renowned for their rapid growth and adaptability. In Brazil, one of the most widely grown Eucalyptus cultivars is the fast-growing Eucalyptus urophylla x Eucalyptus grandis hybrid. In a previous study, we described a chemical characterization of these hybrids when subjected to flavonoid supplementation on 2 distinct timetables, and our results revealed marked differences between the wood composition of the treated and untreated trees. In this work, we report the transcriptional responses occurring in these trees that may be related to the observed chemical differences. Gene expression was analysed through mRNA-sequencing, and notably, compared to control trees, the treated trees display differential down-regulation of cell wall formation pathways such as phenylpropanoid metabolism as well as differential expression of genes involved in sucrose, starch and minor CHO metabolism and genes that play a role in several stress and environmental responses. We also performed enzymatic hydrolysis of wood samples from the different treatments, and the results indicated higher sugar contents and glucose yields in the flavonoid-treated plants. Our results further illustrate the potential use of flavonoids as a nutritional complement for modifying Eucalyptus wood, since, supplementation with flavonoids alters its chemical composition, gene expression and increases saccharification probably as part of a stress response.

  16. Intraseasonal carbon sequestration and allocation in larch trees growing on permafrost in Siberia after 13C labeling (two seasons of 2013-2014 observation).

    Science.gov (United States)

    Masyagina, Oxana; Prokushkin, Anatoly; Kirdyanov, Alexander; Artyukhov, Aleksey; Udalova, Tatiana; Senchenkov, Sergey; Rublev, Aleksey

    2016-12-01

    This research is an attempt to study seasonal translocation patterns of photoassimilated carbon within trees of one of the high latitudes widespread deciduous conifer species Larix gmelinii (Rupr. Rupr). For this purpose, we applied whole-tree labeling by 13 CO 2 , which is a powerful and effective tool for tracing newly developed assimilates translocation to tissues and organs of a tree. Experimental plot has been established in a mature 105-year-old larch stand located within the continuous permafrost area near Tura settlement (Central Siberia, 64°17'13″N, 100°11'55″E, 148 m a.s.l.). Measurements of seasonal photosynthetic activity and foliage parameters (i.e., leaf length, area, biomass, etc.), and sampling were arranged from early growing season (June 8, 2013; May 14, 2014) until yellowing and senescence of needles (September 17, 2013; September 14, 2014). Labeling by 13 C of the tree branch (June 2013, for 3 branch replicates in 3 different trees) and the whole tree was conducted at early (June 2014), middle (July 2014), and late (August 2013) phase of growing season (for different trees in 3 replicates each time) by three pulses [(CO 2 )max = 3000-4000 ppmv, 13 CO 2 (30 % v/v)]. We found at least two different patterns of carbon translocation associated with larch CO 2 assimilation depending on needle phenology. In early period of growing season (June), 13 C appearing in newly developed needles is a result of remobilized storage material use for growth purposes. Then approximately at the end of June, growth processes is switching to storage processes lasting to the end of growing season.

  17. Section-Based Tree Species Identification Using Airborne LIDAR Point Cloud

    Science.gov (United States)

    Yao, C.; Zhang, X.; Liu, H.

    2017-09-01

    The application of LiDAR data in forestry initially focused on mapping forest community, particularly and primarily intended for largescale forest management and planning. Then with the smaller footprint and higher sampling density LiDAR data available, detecting individual tree overstory, estimating crowns parameters and identifying tree species are demonstrated practicable. This paper proposes a section-based protocol of tree species identification taking palm tree as an example. Section-based method is to detect objects through certain profile among different direction, basically along X-axis or Y-axis. And this method improve the utilization of spatial information to generate accurate results. Firstly, separate the tree points from manmade-object points by decision-tree-based rules, and create Crown Height Mode (CHM) by subtracting the Digital Terrain Model (DTM) from the digital surface model (DSM). Then calculate and extract key points to locate individual trees, thus estimate specific tree parameters related to species information, such as crown height, crown radius, and cross point etc. Finally, with parameters we are able to identify certain tree species. Comparing to species information measured on ground, the portion correctly identified trees on all plots could reach up to 90.65 %. The identification result in this research demonstrate the ability to distinguish palm tree using LiDAR point cloud. Furthermore, with more prior knowledge, section-based method enable the process to classify trees into different classes.

  18. Phylogenetic affinity of tree shrews to Glires is attributed to fast evolution rate.

    Science.gov (United States)

    Lin, Jiannan; Chen, Guangfeng; Gu, Liang; Shen, Yuefeng; Zheng, Meizhu; Zheng, Weisheng; Hu, Xinjie; Zhang, Xiaobai; Qiu, Yu; Liu, Xiaoqing; Jiang, Cizhong

    2014-02-01

    Previous phylogenetic analyses have led to incongruent evolutionary relationships between tree shrews and other suborders of Euarchontoglires. What caused the incongruence remains elusive. In this study, we identified 6845 orthologous genes between seventeen placental mammals. Tree shrews and Primates were monophyletic in the phylogenetic trees derived from the first or/and second codon positions whereas tree shrews and Glires formed a monophyly in the trees derived from the third or all codon positions. The same topology was obtained in the phylogeny inference using the slowly and fast evolving genes, respectively. This incongruence was likely attributed to the fast substitution rate in tree shrews and Glires. Notably, sequence GC content only was not informative to resolve the controversial phylogenetic relationships between tree shrews, Glires, and Primates. Finally, estimation in the confidence of the tree selection strongly supported the phylogenetic affiliation of tree shrews to Primates as a monophyly. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Tree Species Identity Shapes Earthworm Communities

    Directory of Open Access Journals (Sweden)

    Stephanie Schelfhout

    2017-03-01

    Full Text Available Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden experiment, replicated six times over Denmark, six tree species were planted in blocks: sycamore maple (Acer pseudoplatanus, beech (Fagus sylvatica, ash (Fraxinus excelsior, Norway spruce (Picea abies, pedunculate oak (Quercus robur and lime (Tilia cordata. We studied the chemical characteristics of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer and Tilia, which is related to calcium-rich litter and low soil acidification. Epigeic earthworms were indifferent to calcium content in leaf litter and were shown to be mainly related to soil moisture content and litter C:P ratios. Almost no earthworms were found in Picea stands, likely because of the combined effects of recalcitrant litter, low pH and low soil moisture content.

  20. Cheap heat grows in fields

    International Nuclear Information System (INIS)

    Haluza, I.

    2006-01-01

    Slovak farmers resemble the peasants from the film T he Magnificent Seven . They keep complaining about their fate but consider any innovation as an interference. And that is why they still have not started growing fast-growing wood although the number of heating plants processing bio-mass from forests and fields is growing. Natural gas is expensive and coal creates pollution. Energy from biomass is becoming a good business and also creates new business opportunities - growing the raw material it needs. Such heating plants usually use waste from wood processing companies and Slovak Forests (Lesy SR) has also started deliveries of chip wood from old forests. There are plantations of fast growing wood suitable for heat production of over 500-thousand hectares throughout the EU. This is about 10% of Slovakian's area where the first plantations are also already being set up. The first promising plantation project was launched this spring. And this is not a project launched and backed by a big company but a starting up businessman, Miroslav Forgac from Kosice. He founded his company, Forgim, last winter. Without big money involved and thank to a new business idea he managed to persuade farmers to set up the first plantations. He supplied the seedlings and the business has started with 75 ha of plantations around Trnava, Sala, Komarno, Lucenec, Poprad and Kosice. He is gradually signing contracts with other landowners and next year the area of plantations is set to grow by 1500 ha. Plantations of fast growing trees such as willow, poplar and acacia regenerate by new trees growing out of the roots of the old and from cut trees so from one seedling and one investment there can be several harvests. Swedish willows from Forgim regenerate 20 to 25 years after the first planting. And only then new seedlings have to be purchased. Using special machines that even cut the wood to wood chips the plantations can be 'harvested' every three years. Unlike crops, the fields do not

  1. Understanding recruitment failure in tropical tree species: Insights from a tree ring study

    NARCIS (Netherlands)

    Vlam, M.; Baker, P.J.; Bunyavejchewin, S.; Mohren, G.M.J.; Zuidema, P.A.

    2014-01-01

    Many tropical tree species have population structures that exhibit strong recruitment failure. While the presence of adult trees indicates that appropriate regeneration conditions occurred in the past, it is often unclear why small individuals are absent. Knowing how, when and where these tree

  2. The abundance and diversity of legume-nodulating rhizobia in 28-year-old plantations of tropical, subtropical, and exotic tree species: a case study from the Forest Reserve of Bandia, Senegal.

    Science.gov (United States)

    Sene, Godar; Thiao, Mansour; Samba-Mbaye, Ramatoulaye; Khasa, Damase; Kane, Aboubacry; Mbaye, Mame Samba; Beaulieu, Marie-Ève; Manga, Anicet; Sylla, Samba Ndao

    2013-01-01

    Several fast-growing and multipurpose tree species have been widely used in West Africa to both reverse the tendency of land degradation and restore soil productivity. Although beneficial effects have been reported on soil stabilization, there still remains a lack of information about their impact on soil microorganisms. Our investigation has been carried out in exotic and native tree plantations of 28 years and aimed to survey and compare the abundance and genetic diversity of natural legume-nodulating rhizobia (LNR). The study of LNR is supported by the phylogenetic analysis which clustered the isolates into three genera: Bradyrhizobium, Mesorhizobium, and Sinorhizobium. The results showed close positive correlations between the sizes of LNR populations estimated both in the dry and rainy seasons and the presence of legume tree hosts. There were significant increases in Rhizobium spp. population densities in response to planting with Acacia spp., and high genetic diversities and richness of genotypes were fittest in these tree plantations. This suggests that enrichment of soil Rhizobium spp. populations is host specific. The results indicated also that species of genera Mesorhizobium and Sinorhizobium were lacking in plantations of non-host species. By contrast, there was a widespread distribution of Bradyrhizobium spp. strains across the tree plantations, with no evident specialization in regard to plantation type. Finally, the study provides information about the LNR communities associated with a range of old tree plantations and some aspects of their relationships to soil factors, which may facilitate the management of man-made forest systems that target ecosystem rehabilitation and preservation of soil biota.

  3. Testing for Polytomies in Phylogenetic Species Trees Using Quartet Frequencies.

    Science.gov (United States)

    Sayyari, Erfan; Mirarab, Siavash

    2018-02-28

    Phylogenetic species trees typically represent the speciation history as a bifurcating tree. Speciation events that simultaneously create more than two descendants, thereby creating polytomies in the phylogeny, are possible. Moreover, the inability to resolve relationships is often shown as a (soft) polytomy. Both types of polytomies have been traditionally studied in the context of gene tree reconstruction from sequence data. However, polytomies in the species tree cannot be detected or ruled out without considering gene tree discordance. In this paper, we describe a statistical test based on properties of the multi-species coalescent model to test the null hypothesis that a branch in an estimated species tree should be replaced by a polytomy. On both simulated and biological datasets, we show that the null hypothesis is rejected for all but the shortest branches, and in most cases, it is retained for true polytomies. The test, available as part of the Accurate Species TRee ALgorithm (ASTRAL) package, can help systematists decide whether their datasets are sufficient to resolve specific relationships of interest.

  4. Testing for Polytomies in Phylogenetic Species Trees Using Quartet Frequencies

    Science.gov (United States)

    Sayyari, Erfan

    2018-01-01

    Phylogenetic species trees typically represent the speciation history as a bifurcating tree. Speciation events that simultaneously create more than two descendants, thereby creating polytomies in the phylogeny, are possible. Moreover, the inability to resolve relationships is often shown as a (soft) polytomy. Both types of polytomies have been traditionally studied in the context of gene tree reconstruction from sequence data. However, polytomies in the species tree cannot be detected or ruled out without considering gene tree discordance. In this paper, we describe a statistical test based on properties of the multi-species coalescent model to test the null hypothesis that a branch in an estimated species tree should be replaced by a polytomy. On both simulated and biological datasets, we show that the null hypothesis is rejected for all but the shortest branches, and in most cases, it is retained for true polytomies. The test, available as part of the Accurate Species TRee ALgorithm (ASTRAL) package, can help systematists decide whether their datasets are sufficient to resolve specific relationships of interest. PMID:29495636

  5. Comparison of Rooting Strategies to Explore Rock Fractures for Shallow Soil-Adapted Tree Species with Contrasting Aboveground Growth Rates: A Greenhouse Microcosm Experiment.

    Science.gov (United States)

    Nie, Yunpeng; Chen, Hongsong; Ding, Yali; Yang, Jing; Wang, Kelin

    2017-01-01

    For tree species adapted to shallow soil environments, rooting strategies that efficiently explore rock fractures are important because soil water depletion occurs frequently. However, two questions: (a) to what extent shallow soil-adapted species rely on exploring rock fractures and (b) what outcomes result from drought stress, have rarely been tested. Therefore, based on the expectation that early development of roots into deep soil layers is at the cost of aboveground growth, seedlings of three tree species ( Cyclobalanopsis glauca, Delavaya toxocarpa , and Acer cinnamomifolium ) with distinct aboveground growth rates were selected from a typical shallow soil region. In a greenhouse experiment that mimics the basic features of shallow soil environments, 1-year-old seedlings were transplanted into simulated microcosms of shallow soil overlaying fractured bedrock. Root biomass allocation and leaf physiological activities, as well as leaf δ 13 C values were investigated and compared for two treatments: regular irrigation and repeated cycles of drought stress. Our results show that the three species differed in their rooting strategies in the context of encountering rock fractures, however, these strategies were not closely related to the aboveground growth rate. For the slowest-growing seedling, C. glauca , percentages of root mass in the fractures, as well as in the soil layer between soil and bedrock increased significantly under both treatments, indicating a specialized rooting strategy that facilitated the exploration of rock fractures. Early investment in deep root growth was likely critical to the establishment of this drought-vulnerable species. For the intermediate-growing, A. cinnamomifolium , percentages of root mass in the bedrock and interface soil layers were relatively low and exhibited no obvious change under either treatment. This limited need to explore rock fractures was compensated by a conservative water use strategy. For the fast-growing, D

  6. Comparison of Rooting Strategies to Explore Rock Fractures for Shallow Soil-Adapted Tree Species with Contrasting Aboveground Growth Rates: A Greenhouse Microcosm Experiment

    Directory of Open Access Journals (Sweden)

    Yunpeng Nie

    2017-09-01

    Full Text Available For tree species adapted to shallow soil environments, rooting strategies that efficiently explore rock fractures are important because soil water depletion occurs frequently. However, two questions: (a to what extent shallow soil-adapted species rely on exploring rock fractures and (b what outcomes result from drought stress, have rarely been tested. Therefore, based on the expectation that early development of roots into deep soil layers is at the cost of aboveground growth, seedlings of three tree species (Cyclobalanopsis glauca, Delavaya toxocarpa, and Acer cinnamomifolium with distinct aboveground growth rates were selected from a typical shallow soil region. In a greenhouse experiment that mimics the basic features of shallow soil environments, 1-year-old seedlings were transplanted into simulated microcosms of shallow soil overlaying fractured bedrock. Root biomass allocation and leaf physiological activities, as well as leaf δ13C values were investigated and compared for two treatments: regular irrigation and repeated cycles of drought stress. Our results show that the three species differed in their rooting strategies in the context of encountering rock fractures, however, these strategies were not closely related to the aboveground growth rate. For the slowest-growing seedling, C. glauca, percentages of root mass in the fractures, as well as in the soil layer between soil and bedrock increased significantly under both treatments, indicating a specialized rooting strategy that facilitated the exploration of rock fractures. Early investment in deep root growth was likely critical to the establishment of this drought-vulnerable species. For the intermediate-growing, A. cinnamomifolium, percentages of root mass in the bedrock and interface soil layers were relatively low and exhibited no obvious change under either treatment. This limited need to explore rock fractures was compensated by a conservative water use strategy. For the fast-growing

  7. Evaluation of efficient glucose release using sodium hydroxide and phosphoric acid as pretreating agents from the biomass of Sesbania grandiflora (L.) Pers.: A fast growing tree legume.

    Science.gov (United States)

    Mund, Nitesh K; Dash, Debabrata; Barik, Chitta R; Goud, Vaibhav V; Sahoo, Lingaraj; Mishra, Prasannajit; Nayak, Nihar R

    2017-07-01

    Sesbania grandiflora (L.) Pers. is one of the fast growing tree legumes having the efficiency to produce around 50tha -1 above ground dry matters in a year. In this study, biomass of 2years old S. grandiflora was selected for the chemical composition, pretreatments and enzymatic hydrolysis studies. The stem biomass with a wood density of 3.89±0.01gmcm -3 contains about 38% cellulose, 12% hemicellulose and 28% lignin. Enzymatic hydrolysis of pretreated biomass revealed that phosphoric acid (H 3 PO 4 ) pretreated samples even at lower cellulase loadings [1 Filter Paper Units (FPU)], could efficiently convert about 86% glucose, while, even at higher cellulase loadings (60FPU) alkali pretreated biomass could convert only about 58% glucose. The effectiveness of phosphoric acid pretreatment was also supported by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Tree architecture and life-history strategies across 200 co-occurring tropical tree species

    NARCIS (Netherlands)

    Iida, Y.; Kohyama, T.S.; Kubo, T.; Kassim, A.R.; Poorter, L.; Sterck, F.J.; Potts, M.D.

    2011-01-01

    1. Tree architecture is thought to allow species to partition horizontal and vertical light gradients in the forest canopy. Tree architecture is closely related to light capture, carbon gain and the efficiency with which trees reach the canopy. Previous studies that investigated how light gradients

  9. Mycorrhizal association of some agroforestry tree species in two ...

    African Journals Online (AJOL)

    Mycorrhizal colonization of different agroforestry tree species in two social forestry nurseries was investigated. Percentage of Arbuscular mycorrhizal (AM) infection, number of resting spores and AM fungi species varies both in tree species as well as in two different nurseries. This variation is attributed to various factors such ...

  10. Wood density variation and tree ring distinctness in Gmelina arborea trees by x-ray densitometry

    Directory of Open Access Journals (Sweden)

    Roger Moya

    2009-03-01

    Full Text Available Due to its relationship with other properties, wood density is the main wood quality parameter. Modern, accuratemethods such as X-ray densitometry - are applied to determine the spatial distribution of density in wood sections and to evaluatewood quality. The objectives of this study were to determinate the influence of growing conditions on wood density variation andtree ring demarcation of gmelina trees from fast growing plantations in Costa Rica. The wood density was determined by X-raydensitometry method. Wood samples were cut from gmelina trees and were exposed to low X-rays. The radiographic films weredeveloped and scanned using a 256 gray scale with 1000 dpi resolution and the wood density was determined by CRAD and CERDsoftware. The results showed tree-ring boundaries were distinctly delimited in trees growing in site with rainfall lower than 2510 mm/year. It was demonstrated that tree age, climatic conditions and management of plantation affects wood density and its variability. Thespecific effect of variables on wood density was quantified by for multiple regression method. It was determined that tree yearexplained 25.8% of the total variation of density and 19.9% were caused by climatic condition where the tree growing. Wood densitywas less affected by the intensity of forest management with 5.9% of total variation.

  11. Flexural properties of four fast-growing eucalypts woods deteriorated by three different field tests

    Directory of Open Access Journals (Sweden)

    Rafael de Avila Delucis

    2017-02-01

    Full Text Available Durability is a wood characteristic determined by several factors, making it difficult to investigate the service life of pieces designated for outdoor use. In this study, the decaying of juvenile and adult woods of four fast-growing eucalypts from southern Brazil subjected to three different exposure environments was monitored through mechanical properties (flexural test. The study material was obtained from adult trees of Eucalyptus botryoides, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus tereticornis. Field tests were conducted in the city of Piratini, southern Brazil, and samplings were carried out during 540 days of experiment. Comparing the four eucalypts, the decreasing order of biological resistance was: Eucalyptus tereticornis, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus botryoides. The mature wood showed greater and more stable physical-mechanical properties than juvenile wood.

  12. Wood nitrogen concentrations in tropical trees: phylogenetic patterns and ecological correlates.

    Science.gov (United States)

    Martin, Adam R; Erickson, David L; Kress, W John; Thomas, Sean C

    2014-11-01

    In tropical and temperate trees, wood chemical traits are hypothesized to covary with species' life-history strategy along a 'wood economics spectrum' (WES), but evidence supporting these expected patterns remains scarce. Due to its role in nutrient storage, we hypothesize that wood nitrogen (N) concentration will covary along the WES, being higher in slow-growing species with high wood density (WD), and lower in fast-growing species with low WD. In order to test this hypothesis we quantified wood N concentrations in 59 Panamanian hardwood species, and used this dataset to examine ecological correlates and phylogenetic patterns of wood N. Wood N varied > 14-fold among species between 0.04 and 0.59%; closely related species were more similar in wood N than expected by chance. Wood N was positively correlated with WD, and negatively correlated with log-transformed relative growth rates, although these relationships were relatively weak. We found evidence for co-evolution between wood N and both WD and log-transformed mortality rates. Our study provides evidence that wood N covaries with tree life-history parameters, and that these patterns consistently co-evolve in tropical hardwoods. These results provide some support for the hypothesized WES, and suggest that wood is an increasingly important N pool through tropical forest succession. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  13. tropiTree: An NGS-Based EST-SSR Resource for 24 Tropical Tree Species

    Science.gov (United States)

    Russell, Joanne R.; Hedley, Peter E.; Cardle, Linda; Dancey, Siobhan; Morris, Jenny; Booth, Allan; Odee, David; Mwaura, Lucy; Omondi, William; Angaine, Peter; Machua, Joseph; Muchugi, Alice; Milne, Iain; Kindt, Roeland; Jamnadass, Ramni; Dawson, Ian K.

    2014-01-01

    The development of genetic tools for non-model organisms has been hampered by cost, but advances in next-generation sequencing (NGS) have created new opportunities. In ecological research, this raises the prospect for developing molecular markers to simultaneously study important genetic processes such as gene flow in multiple non-model plant species within complex natural and anthropogenic landscapes. Here, we report the use of bar-coded multiplexed paired-end Illumina NGS for the de novo development of expressed sequence tag-derived simple sequence repeat (EST-SSR) markers at low cost for a range of 24 tree species. Each chosen tree species is important in complex tropical agroforestry systems where little is currently known about many genetic processes. An average of more than 5,000 EST-SSRs was identified for each of the 24 sequenced species, whereas prior to analysis 20 of the species had fewer than 100 nucleotide sequence citations. To make results available to potential users in a suitable format, we have developed an open-access, interactive online database, tropiTree (http://bioinf.hutton.ac.uk/tropiTree), which has a range of visualisation and search facilities, and which is a model for the efficient presentation and application of NGS data. PMID:25025376

  14. A multi-species synthesis of physiological mechanisms in drought-induced tree mortality

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Henry D.; Zeppel, Melanie J. B.; Anderegg, William R. L.; Hartmann, Henrik; Landhäusser, Simon M.; Tissue, David T.; Huxman, Travis E.; Hudson, Patrick J.; Franz, Trenton E.; Allen, Craig D.; Anderegg, Leander D. L.; Barron-Gafford, Greg A.; Beerling, David J.; Breshears, David D.; Brodribb, Timothy J.; Bugmann, Harald; Cobb, Richard C.; Collins, Adam D.; Dickman, L. Turin; Duan, Honglang; Ewers, Brent E.; Galiano, Lucía; Galvez, David A.; Garcia-Forner, Núria; Gaylord, Monica L.; Germino, Matthew J.; Gessler, Arthur; Hacke, Uwe G.; Hakamada, Rodrigo; Hector, Andy; Jenkins, Michael W.; Kane, Jeffrey M.; Kolb, Thomas E.; Law, Darin J.; Lewis, James D.; Limousin, Jean-Marc; Love, David M.; Macalady, Alison K.; Martínez-Vilalta, Jordi; Mencuccini, Maurizio; Mitchell, Patrick J.; Muss, Jordan D.; O’Brien, Michael J.; O’Grady, Anthony P.; Pangle, Robert E.; Pinkard, Elizabeth A.; Piper, Frida I.; Plaut, Jennifer A.; Pockman, William T.; Quirk, Joe; Reinhardt, Keith; Ripullone, Francesco; Ryan, Michael G.; Sala, Anna; Sevanto, Sanna; Sperry, John S.; Vargas, Rodrigo; Vennetier, Michel; Way, Danielle A.; Xu, Chonggang; Yepez, Enrico A.; McDowell, Nate G.

    2017-08-07

    Widespread tree mortality associated with drought has been observed on all forested continents, and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water, and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analyzed across species and biomes using a standardized physiological framework. Here we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or greater loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrates at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in hydraulic deterioration. The consistent Our finding that across species of hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.

  15. Distribution characteristics of mineral elements in tree Species from ...

    African Journals Online (AJOL)

    Tree species populations were 44 in Akyaakrom (AS), 29 in Dopiri (DS), and families were 18 in AS and 16 in DS. Tree densities were 121 and 99 in AS and DS, respectively, in 0.57 ha. In terms of tree species population, diversity and density, AS was superior to DS. The distribution of major mineral elements in the leaves ...

  16. Modeling Ecosystem Services for Park Trees: Sensitivity of i-Tree Eco Simulations to Light Exposure and Tree Species Classification

    Directory of Open Access Journals (Sweden)

    Rocco Pace

    2018-02-01

    Full Text Available Ecosystem modeling can help decision making regarding planting of urban trees for climate change mitigation and air pollution reduction. Algorithms and models that link the properties of plant functional types, species groups, or single species to their impact on specific ecosystem services have been developed. However, these models require a considerable effort for initialization that is inherently related to uncertainties originating from the high diversity of plant species in urban areas. We therefore suggest a new automated method to be used with the i-Tree Eco model to derive light competition for individual trees and investigate the importance of this property. Since competition depends also on the species, which is difficult to determine from increasingly used remote sensing methodologies, we also investigate the impact of uncertain tree species classification on the ecosystem services by comparing a species-specific inventory determined by field observation with a genus-specific categorization and a model initialization for the dominant deciduous and evergreen species only. Our results show how the simulation of competition affects the determination of carbon sequestration, leaf area, and related ecosystem services and that the proposed method provides a tool for improving estimations. Misclassifications of tree species can lead to large deviations in estimates of ecosystem impacts, particularly concerning biogenic volatile compound emissions. In our test case, monoterpene emissions almost doubled and isoprene emissions decreased to less than 10% when species were estimated to belong only to either two groups instead of being determined by species or genus. It is discussed that this uncertainty of emission estimates propagates further uncertainty in the estimation of potential ozone formation. Overall, we show the importance of using an individual light competition approach and explicitly parameterizing all ecosystem functions at the

  17. Lichens of fruit trees in the selected locations in Podlaskie Voivodeship [North-Eastern Poland

    Directory of Open Access Journals (Sweden)

    Matwiejuk Anna

    2017-12-01

    Full Text Available The aim of this paper is to present the diversity of the lichen species on fruit trees (Malus sp., Pyrus sp., Prunus sp. and Cerasus sp. growing in orchards in selected villages and towns in the Podlaskie Voivodeship. Fifty-six species of lichens were found. These were dominated by common lichens found on the bark of trees growing in built-up areas with prevailing heliophilous and nitrophilous species of the genera Physcia and Phaeophyscia. A richer lichen biota is characteristic of apple trees (52 species and pear trees (36. Lichens of the apple trees constitute 78% of the biota of this phorophyte growing in the fruit orchards in Poland. Of the recorded species, only two (Ramalina farinacea, Usnea hirta are covered by partial protection in Poland.

  18. Effects of tree species, water and nitrogen on mycorrhizal C flux

    Science.gov (United States)

    Menyailo, O.; Matvienko, A.

    2012-12-01

    Mycorrhiza plays an important role in global carbon cycle, especially, in forest soils, yet the effect of tree species on the amount and timing of C transfer through roots to myccorhiza is largely unknown. We studied the C transport to mycorrhiza under 6 most commonly dominant in boreal forests tree species using the mesh collars installed at the Siberian afforestation experiment. The CO2 flux from mycorrhizal and non-mycorrhizal mesh collars indicated the mycorrhizal C flux. Tree species strongly differed in C flux to mycorrhiza: more C was transferred by deciduous species than by conifers. The mycorrhizal CO2 flux was not linked to soil temperature but rather to trees phenology and to photosynthetic activity. All tree species transfered more carbon to mycorrhiza during the second half of summer and in September, this is because all the carbon photosynthesized earlier is used for building the tree biomass. Seasonal variation in C transfer to mycorrhiza was much larger than hourly variation (within a day). Nitrogen application (50 kg/ha) increased mycorrhizal C flux only under Scots pine, but not under larch, thus the effect of N application is tree species dependent. We found under most tree species that more C was transferred by trees to mycorrhiza in root-free collars, where the soil moisture was higher than in collars with roots. This suggests that trees preferentially support those parts of mycorrhiza, which can gain extra-resources.

  19. Transpiration and water-use efficiency in mixed-species forests versus monocultures: effects of tree size, stand density and season.

    Science.gov (United States)

    Forrester, David I

    2015-03-01

    Mixtures can be more productive than monocultures and may therefore use more water, which may make them more susceptible to droughts. The species interactions that influence growth, transpiration and water-use efficiency (WUE, tree growth per unit transpiration) within a given mixture vary with intra- and inter-annual climatic variability, stand density and tree size, but these effects remain poorly quantified. These relationships were examined in mixtures and monocultures of Eucalyptus globulus Labill. and Acacia mearnsii de Wildeman. Growth and transpiration were measured between ages 14 and 15 years. All E. globulus trees in mixture that were growing faster than similar sized trees in monocultures had higher WUE, while trees with similar growth rates had similar WUE. By the age of 14 years A. mearnsii trees were beginning to senesce and there were no longer any relationships between tree size and growth or WUE. The relationship between transpiration and tree size did not differ between treatments for either species, so stand-level increases in transpiration simply reflected the larger mean tree size in mixtures. Increasing neighbourhood basal area increased the complementarity effect on E. globulus growth and transpiration. The complementarity effect also varied throughout the year, but this was not related to the climatic seasonality. This study shows that stand-level responses can be the net effect of a much wider range of individual tree-level responses, but at both levels, if growth has not increased for a given species, it appears unlikely that there will be differences in transpiration or WUE for that species. Growth data may provide a useful initial indication of whether mixtures have higher transpiration or WUE, and which species and tree sizes contribute to this effect. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Species trees for the tree swallows (Genus Tachycineta): an alternative phylogenetic hypothesis to the mitochondrial gene tree.

    Science.gov (United States)

    Dor, Roi; Carling, Matthew D; Lovette, Irby J; Sheldon, Frederick H; Winkler, David W

    2012-10-01

    The New World swallow genus Tachycineta comprises nine species that collectively have a wide geographic distribution and remarkable variation both within- and among-species in ecologically important traits. Existing phylogenetic hypotheses for Tachycineta are based on mitochondrial DNA sequences, thus they provide estimates of a single gene tree. In this study we sequenced multiple individuals from each species at 16 nuclear intron loci. We used gene concatenated approaches (Bayesian and maximum likelihood) as well as coalescent-based species tree inference to reconstruct phylogenetic relationships of the genus. We examined the concordance and conflict between the nuclear and mitochondrial trees and between concatenated and coalescent-based inferences. Our results provide an alternative phylogenetic hypothesis to the existing mitochondrial DNA estimate of phylogeny. This new hypothesis provides a more accurate framework in which to explore trait evolution and examine the evolution of the mitochondrial genome in this group. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Engineering a wild fast-growing Mycoplasma bacterium to generate ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-01-12

    Jan 12, 2018 ... The CCPP bacterium causes sick animals to experience severe symptoms ... because antibiotic treatment does not eliminate the responsible bacterium. ... To develop a fast growing CCPP vaccine for cheaper production and ...

  2. Fostering and sustaining innovation in a Fast Growing Agile Company

    OpenAIRE

    Moe, NilsBrede; Barney, Sebastian; Aurum, Aybüe; Khurum, Mahvish; Wohlin, Claes; Barney, Hamish; Gorschek, Tony; Winata, Martha

    2012-01-01

    Sustaining innovation in a fast growing software development company is difficult. As organisations grow, peoples' focus often changes from the big picture of the product being developed to the specific role they fill. This paper presents two complementary approaches that were successfully used to support continued developer-driven innovation in a rapidly growing Australian agile software development company. The method "FedEx TM Day" gives developers one day to showcase a proof of concept th...

  3. Rapid and accurate species tree estimation for phylogeographic investigations using replicated subsampling.

    Science.gov (United States)

    Hird, Sarah; Kubatko, Laura; Carstens, Bryan

    2010-11-01

    We describe a method for estimating species trees that relies on replicated subsampling of large data matrices. One application of this method is phylogeographic research, which has long depended on large datasets that sample intensively from the geographic range of the focal species; these datasets allow systematicists to identify cryptic diversity and understand how contemporary and historical landscape forces influence genetic diversity. However, analyzing any large dataset can be computationally difficult, particularly when newly developed methods for species tree estimation are used. Here we explore the use of replicated subsampling, a potential solution to the problem posed by large datasets, with both a simulation study and an empirical analysis. In the simulations, we sample different numbers of alleles and loci, estimate species trees using STEM, and compare the estimated to the actual species tree. Our results indicate that subsampling three alleles per species for eight loci nearly always results in an accurate species tree topology, even in cases where the species tree was characterized by extremely rapid divergence. Even more modest subsampling effort, for example one allele per species and two loci, was more likely than not (>50%) to identify the correct species tree topology, indicating that in nearly all cases, computing the majority-rule consensus tree from replicated subsampling provides a good estimate of topology. These results were supported by estimating the correct species tree topology and reasonable branch lengths for an empirical 10-locus great ape dataset. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Low host-tree preferences among saproxylic beetles : acomparison of four deciduous species

    OpenAIRE

    Milberg, Per; Bergman, Karl-Olof; Johansson, Helena; Jansson, Nicklas

    2014-01-01

    Many wood-dwelling beetles rely on old hollow trees. In Europe, oaks are known to harbour a species-rich saproxylic beetle fauna, while less is known regarding other broad-leaved tree species. Furthermore, the extent to which saproxylic insect species have specialised on different tree species remains unknown. In this study, we sampled beetles through pitfall traps and window traps in four different tree species in a landscape with many old oaks. We recorded 242 saproxylic beetle species of w...

  5. Age class, longevity and growth rate relationships: protracted growth increases in old trees in the eastern United States.

    Science.gov (United States)

    Johnson, Sarah E; Abrams, Marc D

    2009-11-01

    This study uses data from the International Tree-Ring Data Bank website and tree cores collected in the field to explore growth rate (basal area increment, BAI) relationships across age classes (from young to old) for eight tree species in the eastern US. These species represent a variety of ecological traits and include those in the genera Populus, Quercus, Pinus, Tsuga and Nyssa. We found that most trees in all age classes and species exhibit an increasing BAI throughout their lives. This is particularly unusual for trees in the older age classes that we expected to have declining growth in the later years, as predicted by physiological growth models. There exists an inverse relationship between growth rate and increasing age class. The oldest trees within each species have consistently slow growth throughout their lives, implying an inverse relationship between growth rate and longevity. Younger trees (trees when they are of the same age resulting from a higher proportion of fast-growing trees in these young age classes. Slow, but increasing, BAI in the oldest trees in recent decades is a continuation of their growth pattern established in previous centuries. The fact that they have not shown a decreasing growth rate in their old age contradicts physiological growth models and may be related to the stimulatory effects of global change phenomenon (climate and land-use history).

  6. Effects of acid rain and surfactant pollution on the foliar structure of some tree species

    International Nuclear Information System (INIS)

    Raddi, P.; Moricca, S.; Paoletti, E.

    1994-01-01

    For 10 years we have been studying the effects of acid rain and ABS (a surfactant always found in sea aerosols) on several tree species. Alterations of the leaf structure were considered as damage index. We tried to quantify the damage to the wax structure by scoring in accordance with a damage scale given by SEM observations and by computing a damage index that allowed for a comparison among tree provenances and within individuals of the same provenance or clone. We tested the response of several species: Norway spruce, silver fir, cypress, London plane, chestnut, walnut, Italian alder, tree of heaven, common maple, European white elm, manna ash, holm oak, European beech. The different species exhibited different levels of damage in relation to the type of treatment: when ABS was present, the damage was always more severe. In the broadleaved trees, the most frequent disturbances noted were: erosion of the epicuticular wax, alterations in the stomata, lesions, abscission and/or alternation of hairs. Damage from ABS treatments was compared to damge observed in coastal vegetation after strong sea winds. By comparing natural and induced damage, we were able to demonstrate that ABS is one of the possible causes of coastal vegetation decline and that ABS may also impact significantly on vegetation growing far away from the sea. (orig.)

  7. Early and late seasonal carbon sequestration and allocation in larch trees growing on permafrost in Central Siberia

    Science.gov (United States)

    Masyagina, Oxana; Prokushkin, Anatoly; Kirdyanov, Alexander; Artyukhov, Aleksey; Udalova, Tatiana; Senchenkov, Sergey; Rublev, Aleksey

    2014-05-01

    Despite large geographic extent of deciduous conifer species Larix gmelinii, its seasonal photosynthetic activity and translocation of photoassimilated carbon within a tree remain poorly studied. To get better insight into productivity of larch trees growing on permafrost soils in Siberian larch biome we aimed to analyze dynamics of foliage parameters (i.e. leaf area, biomass, %N, %P etc.), seasonal dynamics of photosynthetic activity and apply whole tree labeling by 13CO2, which is powerful and effective tool for tracing newly developed assimilates translocation to tissues and organs of a tree (Kagawa et al., 2006; Keel et al., 2012). Experimental plot has been established in mature 105 year-old larch stand located within the continuous permafrost area near Tura settlement (Central Siberia, 64o17'13" N, 100o11'55" E, 148 m a.s.l.). Trees selected for experiments represented mean tree of the stand. Measurements of seasonal photosynthetic activity and foliar biomass sampling were arranged from early growing season (June 8, 2013) until yellowing and senescence of needles on September 17, 2013. Labeling by 13C in whole tree chamber was conducted by three pulses ([CO2]max ≤ 2,500 ppmv, 13CO2 (30% v/v)) at the early (June) and late (August) phase of growing season for different trees in 3 replicates each time. Both early season and late season labeling experiments demonstrated high rate of 13CO2 assimilation and respective enrichment of needle tissues by 13C: δ13C increased from -28.7 up to +670‰ just after labeling. However, there was distinct post-labeling dynamics of needle δ13C among two seasonal experiments. At the early season 13C depletion in labeled needles was slower, and δ13C approached after 40 days ca. +110 ‰ and remained constant till senescence. In the late season (August) needles were losing labeled C with much faster rate and approached only +1.5 ‰ upon senescence (28 days exposition). These findings suggest that in early season ca. 20% of

  8. VHDL Implementation of a Fast Adder Tree

    OpenAIRE

    Dacheng, Chen

    2005-01-01

    This thesis discusses the design and implementation of a VHDL generator for Wallace tree with (3:2) counter modules and (2:2) counter modules to solve fast addition problem. The basic research has been carried out by MATLAB programming environment and automatic generation of VHDL file based on the result obtained from MATLAB simulation. MODELSIM has been used for compilation and simulation of the VHDL file.

  9. Tree diversity and canopy cover in cocoa systems in Ghana

    DEFF Research Database (Denmark)

    Asare, Richard; Ræbild, Anders

    2016-01-01

    Cocoa (Theobroma cacao L.) growing systems in Ghana and West Africa consist of diverse tree species and densities.This study was conducted to determine factors that influence tree species configurations and how tree characteristics affect canopy cover in cocoa farms. Eighty-six farmers...

  10. Time Series of Images to Improve Tree Species Classification

    Science.gov (United States)

    Miyoshi, G. T.; Imai, N. N.; de Moraes, M. V. A.; Tommaselli, A. M. G.; Näsi, R.

    2017-10-01

    Tree species classification provides valuable information to forest monitoring and management. The high floristic variation of the tree species appears as a challenging issue in the tree species classification because the vegetation characteristics changes according to the season. To help to monitor this complex environment, the imaging spectroscopy has been largely applied since the development of miniaturized sensors attached to Unmanned Aerial Vehicles (UAV). Considering the seasonal changes in forests and the higher spectral and spatial resolution acquired with sensors attached to UAV, we present the use of time series of images to classify four tree species. The study area is an Atlantic Forest area located in the western part of São Paulo State. Images were acquired in August 2015 and August 2016, generating three data sets of images: only with the image spectra of 2015; only with the image spectra of 2016; with the layer stacking of images from 2015 and 2016. Four tree species were classified using Spectral angle mapper (SAM), Spectral information divergence (SID) and Random Forest (RF). The results showed that SAM and SID caused an overfitting of the data whereas RF showed better results and the use of the layer stacking improved the classification achieving a kappa coefficient of 18.26 %.

  11. Drought stress limits the geographic ranges of two tree species via different physiological mechanisms.

    Science.gov (United States)

    Anderegg, Leander D L; HilleRisLambers, Janneke

    2016-03-01

    Range shifts are among the most ubiquitous ecological responses to anthropogenic climate change and have large consequences for ecosystems. Unfortunately, the ecophysiological forces that constrain range boundaries are poorly understood, making it difficult to mechanistically project range shifts. To explore the physiological mechanisms by which drought stress controls dry range boundaries in trees, we quantified elevational variation in drought tolerance and in drought avoidance-related functional traits of a widespread gymnosperm (ponderosa pine - Pinus ponderosa) and angiosperm (trembling aspen - Populus tremuloides) tree species in the southwestern USA. Specifically, we quantified tree-to-tree variation in growth, water stress (predawn and midday xylem tension), drought avoidance traits (branch conductivity, leaf/needle size, tree height, leaf area-to-sapwood area ratio), and drought tolerance traits (xylem resistance to embolism, hydraulic safety margin, wood density) at the range margins and range center of each species. Although water stress increased and growth declined strongly at lower range margins of both species, ponderosa pine and aspen showed contrasting patterns of clinal trait variation. Trembling aspen increased its drought tolerance at its dry range edge by growing stronger but more carbon dense branch and leaf tissues, implying an increased cost of growth at its range boundary. By contrast, ponderosa pine showed little elevational variation in drought-related traits but avoided drought stress at low elevations by limiting transpiration through stomatal closure, such that its dry range boundary is associated with limited carbon assimilation even in average climatic conditions. Thus, the same climatic factor (drought) may drive range boundaries through different physiological mechanisms - a result that has important implications for process-based modeling approaches to tree biogeography. Further, we show that comparing intraspecific patterns of

  12. Global variation in woodpecker species richness shaped by tree availability

    DEFF Research Database (Denmark)

    Ilsoe, Sigrid Kistrup; Kissling, W. Daniel; Fjeldsa, Jon

    2017-01-01

    . Location: Global. Methods: We used spatial and non-spatial regressions to test for relationships between broad-scale woodpecker species richness and predictor variables describing current and deep-time availability of trees, current climate, Quaternary climate change, human impact, topographical...... a negative indirect effect on woodpecker species richness. Main conclusions: Global species richness of woodpeckers is primarily shaped by current tree cover and precipitation, reflecting a strong biotic association between woodpeckers and trees. Human influence can have a negative effect on woodpecker....... As an example, woodpeckers (Picidae) are closely associated with trees and woody habitats because of multiple morphological and ecological specializations. In this study, we test whether this strong biotic association causes woodpecker diversity to be closely linked to tree availability at a global scale...

  13. Pervasive phosphorus limitation of tree species but not communities in tropical forests

    Science.gov (United States)

    Turner, Benjamin L.; Brenes-Arguedas, Tania; Condit, Richard

    2018-03-01

    Phosphorus availability is widely assumed to limit primary productivity in tropical forests, but support for this paradigm is equivocal. Although biogeochemical theory predicts that phosphorus limitation should be prevalent on old, strongly weathered soils, experimental manipulations have failed to detect a consistent response to phosphorus addition in species-rich lowland tropical forests. Here we show, by quantifying the growth of 541 tropical tree species across a steep natural phosphorus gradient in Panama, that phosphorus limitation is widespread at the level of individual species and strengthens markedly below a threshold of two parts per million exchangeable soil phosphate. However, this pervasive species-specific phosphorus limitation does not translate into a community-wide response, because some species grow rapidly on infertile soils despite extremely low phosphorus availability. These results redefine our understanding of nutrient limitation in diverse plant communities and have important implications for attempts to predict the response of tropical forests to environmental change.

  14. The relationship between species diversity and genetic structure in the rare Picea chihuahuana tree species community, Mexico.

    Science.gov (United States)

    Simental-Rodríguez, Sergio Leonel; Quiñones-Pérez, Carmen Zulema; Moya, Daniel; Hernández-Tecles, Enrique; López-Sánchez, Carlos Antonio; Wehenkel, Christian

    2014-01-01

    Species diversity and genetic diversity, the most basic elements of biodiversity, have long been treated as separate topics, although populations evolve within a community context. Recent studies on community genetics and ecology have suggested that genetic diversity is not completely independent of species diversity. The Mexican Picea chihuahuana Martínez is an endemic species listed as "Endangered" on the Red List. Forty populations of Chihuahua spruce have been identified. This species is often associated with tree species of eight genera in gallery forests. This rare Picea chihuahuana tree community covers an area no more than 300 ha and has been subject of several studies involving different topics such as ecology, genetic structure and climate change. The overall aim of these studies was to obtain a dataset for developing management tools to help decision makers implement preservation and conservation strategies. However, this unique forest tree community may also represent an excellent subject for helping us to understand the interplay between ecological and evolutionary processes in determining community structure and dynamics. The AFLP technique and species composition data were used together to test the hypothesis that species diversity is related to the adaptive genetic structure of some dominant tree species (Picea chihuahuana, Pinus strobiformis, Pseudotsuga menziesii and Populus tremuloides) of the Picea chihuahuana tree community at fourteen locations. The Hill numbers were used as a diversity measure. The results revealed a significant correlation between tree species diversity and genetic structure in Populus tremuloides. Because the relationship between the two levels of diversity was found to be positive for the putative adaptive AFLP detected, genetic and species structures of the tree community were possibly simultaneously adapted to a combination of ecological or environmental factors. The present findings indicate that interactions between

  15. Timber tree-based contour hedgerow system on sloping acid upland soils: the use of 15N in quantifying tree-crop interaction in agroforestry system

    International Nuclear Information System (INIS)

    Rosales, Crispina M.; Pailagao, Charmaine; Grafia, Alfonso O.; Rivera, Faye G.; Mercado, Agustin R. Jr.

    2004-01-01

    As the population pressures in the upland increase, agroforestry is inevitably the most appropriate technology to enhance the productive and protective functions of farming systems to benefit both the people living inside and outside the watersheds in a suitable manner. Contour hedgerow is one of the agroforestry systems suitable for sloping uplands where farmers grow tree crops as hedgerows and food crops as alleycrops. Smallholder farmers in Southeast Asia have begun farming timber trees in association with food crops on infertile soils as the dominant enterprise using their own capital resources. A collaborative study between the International Centre for Research in Agroforestry (ICRAF) and Philippine Nuclear Research Institute (PNRI) was established to evaluate the performance of fast growing timber trees as hedgerows on subsistence cereal based farming systems, and the role of N-fixing trees as interplant in enhancing the growth of the trees as well as the cereal crops. There were 4 fast growing timber trees being compared: Acacia mangium (N-fixing), Gmelina arborea (non-N-fixing), Euclyptus deglupta (non-N-fixing), and Swietenia macrophylla (non-N-fixing). A mangium was also used as interplant to determine its influence on the growth of the non-N-fixing trees as well as to the cereal crops. Ammonium sulfate enriched with 10.12 15 N atom percent was applied in solution to the upland rice, as alleycrop, at the rate of 69 kgN/ha in the isotope subplot in 2 splits: 30 days after emergence and at panicle initiation stage. This study was conducted in acid upland soil in Claveria, Misamis Oriental. Acacia mangium grew faster compared with G. arborea, E. deglupta, while S. macrophylla grew lower. The growth of E. deglupta and G. arborea was positively affected by N-fixing interplant in low soil fertility environment. G. arborea and A. mangium produced the highest lateral pruning biomass supplying organic nutrients to the associated annual crops. The amount of

  16. Italian alder (Alnus cordata/Loisel./Desf. - new species for Allochtonous dendroflora of Serbia

    Directory of Open Access Journals (Sweden)

    Bobinac Martin

    2015-01-01

    Full Text Available The foreign tree species, Alnus cordata/Loisel./Desf. (Italian alder, (Betulaceae/Loisel./Duby, not previously recorded in the dendroflora of Serbia, is described in this paper. Italian alder trees in an experimental plot in the area of Erdevik, aged 11 years, show good vitality and fast growth, and bear fruits since their 10th year. Tree heights are in range from 10.4 to 16.2 m, and diameters at the breast height range from14.6 to 34.9 cm. The morphological properties of leaves, fruiting organs (“cones” and male catkins are in concordance with the values in literature sources, although they show great variability. Since the time of plantation establishment, the absolute minimum air temperature in the nearby meteorological station of Sremska Mitrovica was -26.50C, so it can be assumed that the species is frost hardy. On the basis of the researched properties of Italian alder, it can be concluded that this species can be cultivated in Serbia as an ornamental in urban areas and as a fast growing species in forest plantations for biomass production. [Projekat Ministarstva nauke Republike Srbije, br. 31041: Šumski zasadi u funkciji povećanja pošumljenosti Srbije

  17. Region effects influence local tree species diversity.

    Science.gov (United States)

    Ricklefs, Robert E; He, Fangliang

    2016-01-19

    Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure to distinguish regional influences from local effects has been due, in part, to sampling limitations at small scales, environmental heterogeneity within local or regional samples, and incomplete geographic sampling of species. Here, we use a global dataset comprising 47 forest plots to demonstrate significant region effects on diversity, beyond the influence of local climate, which together explain more than 92% of the global variation in local forest tree species richness. Significant region effects imply that large-scale processes shaping the regional diversity of forest trees exert influence down to the local scale, where they interact with local processes to determine the number of coexisting species.

  18. A multi-species synthesis of physiological mechanisms in drought-induced tree mortality.

    Science.gov (United States)

    Adams, Henry D; Zeppel, Melanie J B; Anderegg, William R L; Hartmann, Henrik; Landhäusser, Simon M; Tissue, David T; Huxman, Travis E; Hudson, Patrick J; Franz, Trenton E; Allen, Craig D; Anderegg, Leander D L; Barron-Gafford, Greg A; Beerling, David J; Breshears, David D; Brodribb, Timothy J; Bugmann, Harald; Cobb, Richard C; Collins, Adam D; Dickman, L Turin; Duan, Honglang; Ewers, Brent E; Galiano, Lucía; Galvez, David A; Garcia-Forner, Núria; Gaylord, Monica L; Germino, Matthew J; Gessler, Arthur; Hacke, Uwe G; Hakamada, Rodrigo; Hector, Andy; Jenkins, Michael W; Kane, Jeffrey M; Kolb, Thomas E; Law, Darin J; Lewis, James D; Limousin, Jean-Marc; Love, David M; Macalady, Alison K; Martínez-Vilalta, Jordi; Mencuccini, Maurizio; Mitchell, Patrick J; Muss, Jordan D; O'Brien, Michael J; O'Grady, Anthony P; Pangle, Robert E; Pinkard, Elizabeth A; Piper, Frida I; Plaut, Jennifer A; Pockman, William T; Quirk, Joe; Reinhardt, Keith; Ripullone, Francesco; Ryan, Michael G; Sala, Anna; Sevanto, Sanna; Sperry, John S; Vargas, Rodrigo; Vennetier, Michel; Way, Danielle A; Xu, Chonggang; Yepez, Enrico A; McDowell, Nate G

    2017-09-01

    Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.

  19. A multi-species synthesis of physiological mechanisms in drought-induced tree mortality

    Science.gov (United States)

    Adams, Henry D.; Zeppel, Melanie; Anderegg, William R.L.; Hartmann, Henrik; Landhäusser, Simon M.; Tissue, David T.; Huxman, Travis E.; Hudson, Patrick J.; Franz, Trenton E.; Allen, Craig D.; Anderegg, Leander D. L.; Barron-Gafford, Greg A.; Beerling, David; Breshears, David D.; Brodribb, Timothy J.; Bugmann, Harald; Cobb, Richard C.; Collins, Adam D.; Dickman, L. Turin; Duan, Honglang; Ewers, Brent E.; Galiano, Lucia; Galvez, David A.; Garcia-Forner, Núria; Gaylord, Monica L.; Germino, Matthew J.; Gessler, Arthur; Hacke, Uwe G.; Hakamada, Rodrigo; Hector, Andy; Jenkins, Michael W.; Kane, Jeffrey M.; Kolb, Thomas E.; Law, Darin J.; Lewis, James D.; Limousin, Jean-Marc; Love, David; Macalady, Alison K.; Martinez-Vilalta, Jordi; Mencuccini, Maurizio; Mitchell, Patrick J.; Muss, Jordan D.; O'Brien, Michael J.; O'Grady, Anthony P.; Pangle, Robert E.; Pinkard, Elizabeth A.; Piper, Frida I.; Plaut, Jennifer; Pockman, William T.; Quirk, Joe; Reinhardt, Keith; Ripullone, Francesco; Ryan, Michael G.; Sala, Anna; Sevanto, Sanna; Sperry, John S.; Vargas, Rodrigo; Vennetier, Michel; Way, Danielle A.; Wu, Chonggang; Yepez, Enrico A.; McDowell, Nate G.

    2017-01-01

    Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere–atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.

  20. Gene expression profiling of fast- and slow- growing gonadotroph non-functioning pituitary adenomas

    DEFF Research Database (Denmark)

    Falch, Camilla Maria; Sundaram, Arvind Y M; Øystese, Kristin Astrid

    2018-01-01

    Objective Reliable biomarkers associated with aggressiveness of non-functioning gonadotroph adenomas (GAs) are lacking. As the growth of tumor remnants is highly variable, molecular markers for growth potential prediction are necessary. We hypothesized that fast- and slow - growing GAs present......, GPM6A and six EMT-related genes (SPAG9, SKIL, MTDH, HOOK1, CNOT6L and PRKACB). MTDH, but not EMCN, demonstrated involvement in cell migration and association with EMT-markers. Conclusions Fast- and slow- growing GAs present different gene expression profiles and genes related to EMT have higher...... expression in fast-growing tumors. In addition to MTDH, identified as an important contributor to aggressiveness, the other genes might represent markers for tumor growth potential and possible targets for drug therapy. ....

  1. Prospect of Milicia excelsa (Welw. C. Berg for Multi-Tree Species Agroforestry

    Directory of Open Access Journals (Sweden)

    Alfred Ossai Onefeli

    2015-11-01

    Full Text Available Background and Purpose: The population of most of our economically indigenous tree species in Nigeria is declining. Human activities and agricultural practices have been the ultimate contributors to this decrease. In order to ameliorate the conflict between agriculture and forestry, agroforestry was introduced. However, most of the practiced agroforestry is based on single tree species. Agroforestry practiced using single tree species have been reported to be ecologically staggered and therefore it is pertinent that phytosociology of trees with agroforestry potential is studied in order to improve the sustainability of human livelihood. Materials and Methods: This study was carried out in the University of Ibadan’s campus forest. The data were collected on Milicia excelsa (Welw. C. Berg by enumerating the tree species and also by identifying and enumerating the tree species associated with the subject tree (Milicia excelsa. Statistical analysis was done using percentages, Chi-square and charts. Results: A total of 49 individual Milicia excelsa were encountered in the study area. The results show 31 woody tree species associated with Milicia excelsa. Of all the associates Azadirachta indica A.Juss. happened to be the best one, having an average distance of 5.4 m to the subject tree. The sex ratio of Milicia excelsa was discovered to be approximately 1:1. Conclusions: Based on the obtained results of this research it may be concluded that Milicia excelsa has the prospect of being used in agroforestry in multi-tree species systems.

  2. A Very Fast and Angular Momentum Conserving Tree Code

    International Nuclear Information System (INIS)

    Marcello, Dominic C.

    2017-01-01

    There are many methods used to compute the classical gravitational field in astrophysical simulation codes. With the exception of the typically impractical method of direct computation, none ensure conservation of angular momentum to machine precision. Under uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the very fast tree code) conserves linear momentum to machine precision. We show that it is possible to modify this method in a way that conserves both angular and linear momenta.

  3. A Very Fast and Angular Momentum Conserving Tree Code

    Energy Technology Data Exchange (ETDEWEB)

    Marcello, Dominic C., E-mail: dmarce504@gmail.com [Department of Physics and Astronomy, and Center for Computation and Technology Louisiana State University, Baton Rouge, LA 70803 (United States)

    2017-09-01

    There are many methods used to compute the classical gravitational field in astrophysical simulation codes. With the exception of the typically impractical method of direct computation, none ensure conservation of angular momentum to machine precision. Under uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the very fast tree code) conserves linear momentum to machine precision. We show that it is possible to modify this method in a way that conserves both angular and linear momenta.

  4. Remnant trees affect species composition but not structure of tropical second-growth forest.

    Science.gov (United States)

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.

  5. Tree species composition within Kano State University of science ...

    African Journals Online (AJOL)

    The study accessed the tree species composition within the Kano State University of Science and Technology Wudil, Kano State, Nigeria with the view of providing information that will help in the management and conservation of tree species within the campus. The study area was stratified into four (4) sections from which ...

  6. Ethnobotanical survey of tree species used for wound healing in ...

    African Journals Online (AJOL)

    Seventy-one plants out of which sixty-five were tree species belonging to thirty angiosperm families were identified as plant species used for the treatment of wound and related skin disorders. Some of the most frequently used tree species mentioned by the respondents are: Khaya grandifoliola C. D. C., Vitellaria paradoxa ...

  7. Differences between height- and light-dependent changes in shoot traits in five deciduous tree species.

    Science.gov (United States)

    Osada, Noriyuki; Okabe, Yoshihiko; Hayashi, Daisuke; Katsuyama, Tomonori; Tokuchi, Naoko

    2014-01-01

    The effects of tree height on shoot traits may in some cases differ in magnitude and direction from the effects of light. Nevertheless, general patterns of change in shoot traits in relation to variations in height and light have not so far been revealed. A comprehensive analysis of the differences between the effects of height and light on a range of leaf and shoot traits is important for the scaling of these traits to individual trees. We investigated the biomass allocation and structure of current-year shoots at the top of the crowns of five deciduous tree species in Japan. Height effect was investigated by comparing shoot traits among trees of different heights growing under a high light environment. The effects of light were examined by comparing saplings growing in high- and low-light environments. The effects of light were significant for most traits, while those of height were not significant for some traits. The magnitudes of the effects of light were larger than those of height for most traits related to biomass allocation. There was an extreme difference between the effects of height and light in the direction of change in the length of current-year shoots and in the number of standing leaves. The measures of both parameters increased with the increase in light, but decreased with the increase in tree height. Thus, the effects of height and light on diverse traits at the level of current-year shoots were not always similar. These results suggest that great care must be taken when scaling shoot traits from small trees to tall trees because the effects of height and light can be complex.

  8. Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives.

    Science.gov (United States)

    Blair, Jaime E; Coffey, Michael D; Martin, Frank N

    2012-01-01

    To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based "supergene" approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred.

  9. Seedling Growth Strategies in Bauhinia Species: Comparing Lianas and Trees

    Science.gov (United States)

    Cai, Zhi-Quan; Poorter, Lourens; Cao, Kun-Fang; Bongers, Frans

    2007-01-01

    Background and Aims Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass allocation and leaf traits in five closely related liana and tree species of the genus Bauhinia. Methods Seedlings of two light-demanding lianas (Bauhinia tenuiflora and B. claviflora), one shade-tolerant liana (B. aurea), and two light-demanding trees (B. purpurea and B. monandra) were grown in a shadehouse at 25 % of full sunlight. A range of physiological, morphological and biomass parameters at the leaf and whole plant level were compared among these five species. Key Results The two light-demanding liana species had higher relative growth rate (RGR), allocated more biomass to leaf production [higher leaf mass fraction (LMF) and higher leaf area ratio (LAR)] and stem mass fraction (SMF), and less biomass to the roots [root mass fraction (RMF)] than the two tree species. The shade-tolerant liana had the lowest RGR of all five species, and had a higher RMF, lower SMF and similar LMF than the two light-demanding liana species. The two light-demanding lianas had lower photosynthetic rates per unit area (Aarea) and similar photosynthetic rates per unit mass (Amass) than the trees. Across species, RGR was positively related to SLA, but not to LAR and Aarea. Conclusions It is concluded that the faster growth of light-demanding lianas compared with light-demanding trees is based on morphological parameters (SLA, LMF and LAR), and cannot be attributed to higher photosynthetic rates at the leaf level. The shade-tolerant liana exhibited a slow-growth strategy, compared with the light-demanding species. PMID:17720978

  10. Species-level para- and polyphyly in DNA barcode gene trees

    DEFF Research Database (Denmark)

    Mutanen, Marko; Kivelä, Sami M.; Vos, Rutger A.

    2016-01-01

    was paid to accurate species identification to ensure data integrity. We investigated the effects of tree-building method, sampling effort, and other methodological issues, all of which can influence estimates of non-monophyly. We found a 12% incidence of non-monophyly, a value significantly lower than...... between species and gene genealogies, as indicated by situations where conspecific individuals do not form a monophyletic cluster in a gene tree. In two previous reviews, non-monophyly has been reported as being common in mitochondrial DNA gene trees. We developed a novel web service "Monophylizer......" to detect non-monophyly in phylogenetic trees and used it to ascertain the incidence of species non-monophyly in COI (a.k.a. cox1) barcode sequence data from 4977 species and 41,583 specimens of European Lepidoptera, the largest data set of DNA barcodes analyzed from this regard. Particular attention...

  11. Fast Image Texture Classification Using Decision Trees

    Science.gov (United States)

    Thompson, David R.

    2011-01-01

    Texture analysis would permit improved autonomous, onboard science data interpretation for adaptive navigation, sampling, and downlink decisions. These analyses would assist with terrain analysis and instrument placement in both macroscopic and microscopic image data products. Unfortunately, most state-of-the-art texture analysis demands computationally expensive convolutions of filters involving many floating-point operations. This makes them infeasible for radiation- hardened computers and spaceflight hardware. A new method approximates traditional texture classification of each image pixel with a fast decision-tree classifier. The classifier uses image features derived from simple filtering operations involving integer arithmetic. The texture analysis method is therefore amenable to implementation on FPGA (field-programmable gate array) hardware. Image features based on the "integral image" transform produce descriptive and efficient texture descriptors. Training the decision tree on a set of training data yields a classification scheme that produces reasonable approximations of optimal "texton" analysis at a fraction of the computational cost. A decision-tree learning algorithm employing the traditional k-means criterion of inter-cluster variance is used to learn tree structure from training data. The result is an efficient and accurate summary of surface morphology in images. This work is an evolutionary advance that unites several previous algorithms (k-means clustering, integral images, decision trees) and applies them to a new problem domain (morphology analysis for autonomous science during remote exploration). Advantages include order-of-magnitude improvements in runtime, feasibility for FPGA hardware, and significant improvements in texture classification accuracy.

  12. Use of Hardwood Tree Species by Birds Nesting in Ponderosa Pine Forests

    Science.gov (United States)

    Kathryn L. Purcell; Douglas A. Drynan

    2008-01-01

    We examined the use of hardwood tree species for nesting by bird species breeding in ponderosa pine (Pinus ponderosa) forests in the Sierra National Forest, California. From 1995 through 2002, we located 668 nests of 36 bird species nesting in trees and snags on four 60-ha study sites. Two-thirds of all species nesting in trees or snags used...

  13. The hydrological vulnerability of western North American boreal tree species based on ground-based observations of tree mortality

    Science.gov (United States)

    Hember, R. A.; Kurz, W. A.; Coops, N. C.

    2017-12-01

    Several studies indicate that climate change has increased rates of tree mortality, adversely affecting timber supply and carbon storage in western North American boreal forests. Statistical models of tree mortality can play a complimentary role in detecting and diagnosing forest change. Yet, such models struggle to address real-world complexity, including expectations that hydrological vulnerability arises from both drought stress and excess-water stress, and that these effects vary by species, tree size, and competitive status. Here, we describe models that predict annual probability of tree mortality (Pm) of common boreal tree species based on tree height (H), biomass of larger trees (BLT), soil water content (W), reference evapotranspiration (E), and two-way interactions. We show that interactions among H and hydrological variables are consistently significant. Vulnerability to extreme droughts consistently increases as H approaches maximum observed values of each species, while some species additionally show increasing vulnerability at low H. Some species additionally show increasing vulnerability to low W under high BLT, or increasing drought vulnerability under low BLT. These results suggest that vulnerability of trees to increasingly severe droughts depends on the hydraulic efficiency, competitive status, and microclimate of individual trees. Static simulations of Pm across a 1-km grid (i.e., with time-independent inputs of H, BLT, and species composition) indicate complex spatial patterns in the time trends during 1965-2014 and a mean change in Pm of 42 %. Lastly, we discuss how the size-dependence of hydrological vulnerability, in concert with increasingly severe drought events, may shape future responses of stand-level biomass production to continued warming and increasing carbon dioxide concentration in the region.

  14. Multilocus inference of species trees and DNA barcoding.

    Science.gov (United States)

    Mallo, Diego; Posada, David

    2016-09-05

    The unprecedented amount of data resulting from next-generation sequencing has opened a new era in phylogenetic estimation. Although large datasets should, in theory, increase phylogenetic resolution, massive, multilocus datasets have uncovered a great deal of phylogenetic incongruence among different genomic regions, due both to stochastic error and to the action of different evolutionary process such as incomplete lineage sorting, gene duplication and loss and horizontal gene transfer. This incongruence violates one of the fundamental assumptions of the DNA barcoding approach, which assumes that gene history and species history are identical. In this review, we explain some of the most important challenges we will have to face to reconstruct the history of species, and the advantages and disadvantages of different strategies for the phylogenetic analysis of multilocus data. In particular, we describe the evolutionary events that can generate species tree-gene tree discordance, compare the most popular methods for species tree reconstruction, highlight the challenges we need to face when using them and discuss their potential utility in barcoding. Current barcoding methods sacrifice a great amount of statistical power by only considering one locus, and a transition to multilocus barcodes would not only improve current barcoding methods, but also facilitate an eventual transition to species-tree-based barcoding strategies, which could better accommodate scenarios where the barcode gap is too small or inexistent.This article is part of the themed issue 'From DNA barcodes to biomes'. © 2016 The Authors.

  15. Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives.

    Directory of Open Access Journals (Sweden)

    Jaime E Blair

    Full Text Available To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based "supergene" approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred.

  16. Why abundant tropical tree species are phylogenetically old.

    Science.gov (United States)

    Wang, Shaopeng; Chen, Anping; Fang, Jingyun; Pacala, Stephen W

    2013-10-01

    Neutral models of species diversity predict patterns of abundance for communities in which all individuals are ecologically equivalent. These models were originally developed for Panamanian trees and successfully reproduce observed distributions of abundance. Neutral models also make macroevolutionary predictions that have rarely been evaluated or tested. Here we show that neutral models predict a humped or flat relationship between species age and population size. In contrast, ages and abundances of tree species in the Panamanian Canal watershed are found to be positively correlated, which falsifies the models. Speciation rates vary among phylogenetic lineages and are partially heritable from mother to daughter species. Variable speciation rates in an otherwise neutral model lead to a demographic advantage for species with low speciation rate. This demographic advantage results in a positive correlation between species age and abundance, as found in the Panamanian tropical forest community.

  17. Evaluation of phospherus uptake from Minjingu phosphate rock, growth and nodulation of agroforestry tree species on an acid soil from Kenya

    International Nuclear Information System (INIS)

    Karanja, N.K.; Mwendwa, K.A.

    2002-01-01

    A series of studies were carried out to study the effect of P application on fast growing multi-purpose trees. A greenhouse experiment was conducted to evaluate availability and uptake of phosphorus (P) from Minjingu phosphate rock (MPR). An acid soil and six agroforestry tree species namely Leucena leuco-cephala, Gliricidia sepium, Sesbania sesban, Grevillea robusta, Cassia siamea and Eucalyptus grandis were used. Phosphorus was applied at 25.8 mg P/ kg soil as Minjingu phosphate rock (MPR) or Triple Superphosphate (TSP). Pregerminated seedlings were transplanted and divided into two sequential harvests at 3 and 6 MAT (months after transplanting). 32 P isotope carrier free solution was added to transplanted seedlings at the beginning and when they were 3 months old. The soil was tested for isotopically exchangeable P by incubating the soil with the MPR and TSP. The soil was high in P-fixing capacity. At 3 MAT all the species except G. robusta gave a 150-250% significantly higher stem dry weights where P was added and L. leuco-cephala, S. sesban and C. siamea maintained this up to 6 MAT. The legumes and E. grandis where P was applied differed significantly from controls in root dry weight with Minjingu PR being superior with G.sepium and E. grandis. The legumes and E. grandis had significantly higher P uptake where P was applied at 3 MAT. The relative availability of MPR at 3 MAT showed that L.leucocephala and G. sepium derived 2.93 and 1.06 times more P from Minjingu PR than from TSP respectively. Data obtained from G. robusta P uptake showed that this species preferred soil P to externally supplied P in the three sampling periods. Tree species and fertilizer P interactions at 6 MAT were highly significant (P=0.01). Vesicular arbuscular mycorrhiza (VAM) inoculation improved growth, P uptake from MPR and nodulation of G. sepium seedlings. Inoculating L. leucocephala seedlings with VAM increased availability of P from MPR. (author)

  18. Above- and Belowground Development of a Fast-Growing Willow Planted in Acid-Generating Mine Technosol.

    Science.gov (United States)

    Guittonny-Larchevêque, M; Lortie, S

    2017-11-01

    Surface metal mining produces large volumes of waste rocks. If they contain sulfide minerals, these rocks can generate a flow of acidic water from the mining site, known as acid mine drainage (AMD), which increases trace metals availability for plant roots. Adequate root development is crucial to decreasing planting stress and improving phytoremediation with woody species. However, techniques to improve revegetation success rarely take into account root development. An experiment was conducted at a gold mine in Quebec, Canada, to evaluate the establishment ability over 3 yr of a fast-growing willow ( Sx64) planted in acid-generating waste rocks. The main objective was to study root development in the soil profile and trace element accumulation in leaves among substrates varying in thickness (0, 20, and 40 cm of soil) and composition (organic carbon [OC] and alkaline AMD treatment sludge). Trees directly planted in waste rocks survived well (69%) but had the lowest productivity (lowest growth in height and diameter, aerial biomass, total leaf area, and root-system size). By contrast, the treatment richer in OC showed the greatest aerial biomass and total leaf area the first year; the thicker treatment resulted in the greatest growth in height and diameter, aboveground biomass, and root-system size in both the first and third years. Willow root development was restricted to soil layers during the first year, but this restriction was overcome in the third year after planting. Willow accumulation factors in leaves were below one for all investigated trace metals except for zinc (Zn), cadmium (Cd), and strontium. For Cd and Zn, concentrations increased with time in willow foliage, decreasing the potential of this willow species use for phytostabilization, despite its ability to rapidly develop extensive root systems in the mine Technosol. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Variable conductivity and embolism in roots, trunks and branches of tree species growing under future atmospheric CO2 concentration (DUKE FACE site): impacts on whole-plant hydraulic performance and carbon assimilation

    Science.gov (United States)

    domec, J.; Palmroth, S.; Oren, R.; Johnson, D. M.; Ward, E. J.; McCulloh, K.; Gonzalez, C.; Warren, J.

    2013-12-01

    Anatomical and physiological acclimation to water stress of the tree hydraulic system involves tradeoffs between maintenance of stomatal conductance and loss of hydraulic conductivity, with short-term impacts on photosynthesis and long-term consequences to survival and growth. Here we study the role of variations in root, trunk and branch maximum hydraulic specific conductivity (Ks-max) under high and low soil moisture in determining whole-tree hydraulic conductance (Ktree) and in mediating stomatal control of gas exchange in loblolly pine trees growing under ambient and elevated CO2 (CO2a and CO2e). We hypothesized that Ktree would adjust to CO2e, through an increase in root and branch Ks-max in response to anatomical adjustments. Embolism in roots explained the loss of Ktree and therefore indirectly constituted a hydraulic signal involved in stomatal regulation and in the reduction of canopy conductance and carbon assimilation. Across roots, trunk and branches, the increase in Ks-max was associated with a decrease resistance to drought, a consequence of structural acclimation such as larger conduits and lower wood density. In loblolly pine, higher xylem dysfunction under CO2e might impact tree performance in a future climate when increased evaporative demand could cause a greater loss of hydraulic function. The results contributed to our knowledge of the physiological and morphological mechanisms underpinning the responses of tree species to drought and more generally to global change.

  20. Hierarchical Learning of Tree Classifiers for Large-Scale Plant Species Identification.

    Science.gov (United States)

    Fan, Jianping; Zhou, Ning; Peng, Jinye; Gao, Ling

    2015-11-01

    In this paper, a hierarchical multi-task structural learning algorithm is developed to support large-scale plant species identification, where a visual tree is constructed for organizing large numbers of plant species in a coarse-to-fine fashion and determining the inter-related learning tasks automatically. For a given parent node on the visual tree, it contains a set of sibling coarse-grained categories of plant species or sibling fine-grained plant species, and a multi-task structural learning algorithm is developed to train their inter-related classifiers jointly for enhancing their discrimination power. The inter-level relationship constraint, e.g., a plant image must first be assigned to a parent node (high-level non-leaf node) correctly if it can further be assigned to the most relevant child node (low-level non-leaf node or leaf node) on the visual tree, is formally defined and leveraged to learn more discriminative tree classifiers over the visual tree. Our experimental results have demonstrated the effectiveness of our hierarchical multi-task structural learning algorithm on training more discriminative tree classifiers for large-scale plant species identification.

  1. The impact of urban conditions on different tree species in public green areas in the city of Poznan

    Directory of Open Access Journals (Sweden)

    Krzyżaniak Michał

    2015-12-01

    Full Text Available Parks in urbanised areas fulfil an important function as they create a positive climate in cities and contribute to the good health of their inhabitants. The study gives an answer to the question of which of the species under investigation is the most suitable for planting in urbanised areas. The aim of the research conducted from 2013 to 2014 at selected sites in Poznan (Poland was to determine the state of health of Tilia cordata Mill., Acer platanoides L. and Quercus robur L. trees and to compare their state of health depending on the location of the research sites. The aim of the research was also to determine the environmental variables that may have an influence on the state of health of the tree species under analysis. The research included statistical analyses and models based on discriminant analysis. The research revealed that the state of health of the tree species under investigation growing in the city is determined by anthropogenic factors. The closeness of the city centre, main thoroughfares and estates heated with fossil fuels are the factors that have the most negative influence on the state of health of oak, maple and lime trees. Acer platanoides L. was the species in the best state of health in parks, whereas in forests it was Tilia cordata Mill.

  2. Important LiDAR metrics for discriminating forest tree species in Central Europe

    Science.gov (United States)

    Shi, Yifang; Wang, Tiejun; Skidmore, Andrew K.; Heurich, Marco

    2018-03-01

    Numerous airborne LiDAR-derived metrics have been proposed for classifying tree species. Yet an in-depth ecological and biological understanding of the significance of these metrics for tree species mapping remains largely unexplored. In this paper, we evaluated the performance of 37 frequently used LiDAR metrics derived under leaf-on and leaf-off conditions, respectively, for discriminating six different tree species in a natural forest in Germany. We firstly assessed the correlation between these metrics. Then we applied a Random Forest algorithm to classify the tree species and evaluated the importance of the LiDAR metrics. Finally, we identified the most important LiDAR metrics and tested their robustness and transferability. Our results indicated that about 60% of LiDAR metrics were highly correlated to each other (|r| > 0.7). There was no statistically significant difference in tree species mapping accuracy between the use of leaf-on and leaf-off LiDAR metrics. However, combining leaf-on and leaf-off LiDAR metrics significantly increased the overall accuracy from 58.2% (leaf-on) and 62.0% (leaf-off) to 66.5% as well as the kappa coefficient from 0.47 (leaf-on) and 0.51 (leaf-off) to 0.58. Radiometric features, especially intensity related metrics, provided more consistent and significant contributions than geometric features for tree species discrimination. Specifically, the mean intensity of first-or-single returns as well as the mean value of echo width were identified as the most robust LiDAR metrics for tree species discrimination. These results indicate that metrics derived from airborne LiDAR data, especially radiometric metrics, can aid in discriminating tree species in a mixed temperate forest, and represent candidate metrics for tree species classification and monitoring in Central Europe.

  3. Nitrous oxide fluxes from forest floor, tree stems and canopies of boreal tree species during spring

    Science.gov (United States)

    Haikarainen, Iikka; Halmeenmäki, Elisa; Machacova, Katerina; Pihlatie, Mari

    2017-04-01

    Boreal forests are considered as small sources of atmospheric nitrous oxide (N2O) due to microbial N2O production in the soils. Recent evidence shows that trees may play an important role in N2O exchange of forest ecosystems by offering pathways for soil produced N2O to the atmosphere. To confirm magnitude, variability and the origin of the tree mediated N2O emissions more research is needed, especially in boreal forests which have been in a minority in such investigation. We measured forest floor, tree stem and shoot N2O exchange of three boreal tree species at the beginning of the growing season (13.4.-13.6.2015) at SMEAR II station in Hyytiälä, located in Southern Finland (61˚ 51´N, 24˚ 17´E, 181 a.s.l.). The fluxes were measured in silver birch (Betula pendula), downy birch (B. pubescens) and Norway spruce (Picea abies) on two sites with differing soil type and characteristics (paludified and mineral soil), vegetation cover and forest structure. The aim was to study the vertical profile of N2O fluxes at stem level and to observe temporal changes in N2O fluxes over the beginning of the growing season. The N2O exchange was determined using the static chamber technique and gas chromatographic analyses. Scaffold towers were used for measurements at multiple stem heights and at the canopy level. Overall, the N2O fluxes from the forest floor and trees at both sites were very small and close to the detection limit. The measured trees mainly emitted N2O from their stems and shoots, while the forest floor acted as a sink of N2O at the paludified site and as a small source of N2O at the mineral soil site. Stem emissions from all the trees at both sites were on average below 0.5 μg N2O m-2 of stem area h-1, and the shoot emissions varied between 0.2 and 0.5 ng N2O m-2 g-1 dry biomass. When the N2O fluxes were scaled up to the whole forest ecosystem, based on the tree biomass and stand density, the N2O emissions from birch and spruce trees at the paludified site

  4. Grow--a computer subroutine that projects the growth of trees in the Lake States' forests.

    Science.gov (United States)

    Gary J. Brand

    1981-01-01

    A computer subroutine, Grow, has been written in 1977 Standard FORTRAN to implement a distance-independent, individual tree growth model for Lake States' forests. Grow is a small and easy-to-use version of the growth model. All the user has to do is write a calling program to read initial conditions, call Grow, and summarize the results.

  5. Fuelwood quality of promising tree species for alkaline soil sites in relation to tree age

    Energy Technology Data Exchange (ETDEWEB)

    Goel, V.L.; Behl, H.M. [National Botanical Research Inst., Lucknow (India). Biomass Research Center

    1996-06-01

    The fuelwood quality of five tree species suitable for afforestation of alkaline soil sites was investigated in relation to tree age for establishing harvest rotation cycles. Prosopis juliflora and Acacia nilotica were found to be the most suitable species for short rotation fuel wood forestry programmes because of their high wood density, biomass yield, low ash and moisture content, and good heat of combustion at the juvenile stage. The performance of other species like Acacia auriculiformis, Terminalia arjuna and Sesbania formosa is discussed. (author)

  6. Age-related changes in tree growth and physiology

    Science.gov (United States)

    Andrew Groover

    2017-01-01

    Trees pass through specific developmental phases as they age, including juvenile to adult, and vegetative to reproductive phases. The timing of these transitions is regulated genetically but is also highly influenced by the environment. Tree species have evolved different strategies and life histories that affect how they age – for example some pioneer species are fast...

  7. Effects of species biological traits and environmental heterogeneity on simulated tree species distribution shifts under climate change.

    Science.gov (United States)

    Wang, Wen J; He, Hong S; Thompson, Frank R; Spetich, Martin A; Fraser, Jacob S

    2018-09-01

    Demographic processes (fecundity, dispersal, colonization, growth, and mortality) and their interactions with environmental changes are not well represented in current climate-distribution models (e.g., niche and biophysical process models) and constitute a large uncertainty in projections of future tree species distribution shifts. We investigate how species biological traits and environmental heterogeneity affect species distribution shifts. We used a species-specific, spatially explicit forest dynamic model LANDIS PRO, which incorporates site-scale tree species demography and competition, landscape-scale dispersal and disturbances, and regional-scale abiotic controls, to simulate the distribution shifts of four representative tree species with distinct biological traits in the central hardwood forest region of United States. Our results suggested that biological traits (e.g., dispersal capacity, maturation age) were important for determining tree species distribution shifts. Environmental heterogeneity, on average, reduced shift rates by 8% compared to perfect environmental conditions. The average distribution shift rates ranged from 24 to 200myear -1 under climate change scenarios, implying that many tree species may not able to keep up with climate change because of limited dispersal capacity, long generation time, and environmental heterogeneity. We suggest that climate-distribution models should include species demographic processes (e.g., fecundity, dispersal, colonization), biological traits (e.g., dispersal capacity, maturation age), and environmental heterogeneity (e.g., habitat fragmentation) to improve future predictions of species distribution shifts in response to changing climates. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Leaf protein and mineral concentrations across the "miracle tree" genus Moringa

    Science.gov (United States)

    The moringa tree Moringa oleifera is a fast-growing, drought-resistant tree cultivated across the lowland dry tropics worldwide for its nutritious leaves. Despite its nutritious reputation, there has been no systematic survey of the variation in leaf nutritional quality across M. oleifera grown worl...

  9. Effect of automobile pollution on chlorophyll content of roadside urban trees

    Directory of Open Access Journals (Sweden)

    M. Iqbal

    2015-09-01

    Full Text Available The effect of automobile pollution was determined on chlorophyll content of four different tree species viz. Azadirachta indica L., Conocarpus erectus L., Guiacum officinale L.and Eucalyptus sp. growing along the roads of the city.  Significant changes in the level of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” were found in the leaves of four tree species (A. indica, C. erectus, G.officinale and Eucalyptus sp. collected from polluted sites (Airport, Malir Halt, Quaidabad as compared to control site (Karachi University Campus. Lowest concentration of chlorophyll “a”, chlorophyll “b” and chlorophyll “a+b” was recorded in the leaf samples of all tree species collected from Quaidabad site when compared with the leaf samples collected from control site. The highest levels of chlorophyll pigment were recorded in all tree species leave samples collected from Karachi University Campus.  Similarly, better levels of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” was observed in all tree species growing at Airport site as compared to plants growing at Malir Halt and Quaidabad sites.  This study clearly indicated that the vehicular activities induced air pollution problem and affected on the level of chlorophyll pigments in trees which were exposed to road side pollution.

  10. Maintenance of carbohydrate transport in tall trees

    DEFF Research Database (Denmark)

    Savage, Jessica A.; Beecher, Sierra D.; Clerx, Laura

    2017-01-01

    Trees present a critical challenge to long-distance transport because as a tree grows in height and the transport pathway increases in length, the hydraulic resistance of the vascular tissue should increase. This has led many to question whether trees can rely on a passive transport mechanism to ...... that reduce transport resistance. As a result, the key to the long-standing mystery of how trees maintain phloem transport as they increase in size lies in the structure of the phloem and its ability to change hydraulic properties with plant height.......Trees present a critical challenge to long-distance transport because as a tree grows in height and the transport pathway increases in length, the hydraulic resistance of the vascular tissue should increase. This has led many to question whether trees can rely on a passive transport mechanism...... in the leaves of a tall tree in situ. Across nine deciduous species, we find that hydraulic resistance in the phloem scales inversely with plant height because of a shift in sieve element structure along the length of individual trees. This scaling relationship seems robust across multiple species despite large...

  11. Species divergence and phylogenetic variation of ecophysiological traits in lianas and trees.

    Science.gov (United States)

    Rios, Rodrigo S; Salgado-Luarte, Cristian; Gianoli, Ernesto

    2014-01-01

    The climbing habit is an evolutionary key innovation in plants because it is associated with enhanced clade diversification. We tested whether patterns of species divergence and variation of three ecophysiological traits that are fundamental for plant adaptation to light environments (maximum photosynthetic rate [A(max)], dark respiration rate [R(d)], and specific leaf area [SLA]) are consistent with this key innovation. Using data reported from four tropical forests and three temperate forests, we compared phylogenetic distance among species as well as the evolutionary rate, phylogenetic distance and phylogenetic signal of those traits in lianas and trees. Estimates of evolutionary rates showed that R(d) evolved faster in lianas, while SLA evolved faster in trees. The mean phylogenetic distance was 1.2 times greater among liana species than among tree species. Likewise, estimates of phylogenetic distance indicated that lianas were less related than by chance alone (phylogenetic evenness across 63 species), and trees were more related than expected by chance (phylogenetic clustering across 71 species). Lianas showed evenness for R(d), while trees showed phylogenetic clustering for this trait. In contrast, for SLA, lianas exhibited phylogenetic clustering and trees showed phylogenetic evenness. Lianas and trees showed patterns of ecophysiological trait variation among species that were independent of phylogenetic relatedness. We found support for the expected pattern of greater species divergence in lianas, but did not find consistent patterns regarding ecophysiological trait evolution and divergence. R(d) followed the species-level pattern, i.e., greater divergence/evolution in lianas compared to trees, while the opposite occurred for SLA and no pattern was detected for A(max). R(d) may have driven lianas' divergence across forest environments, and might contribute to diversification in climber clades.

  12. TimeTree2: species divergence times on the iPhone.

    Science.gov (United States)

    Kumar, Sudhir; Hedges, S Blair

    2011-07-15

    Scientists, educators and the general public often need to know times of divergence between species. But they rarely can locate that information because it is buried in the scientific literature, usually in a format that is inaccessible to text search engines. We have developed a public knowledgebase that enables data-driven access to the collection of peer-reviewed publications in molecular evolution and phylogenetics that have reported estimates of time of divergence between species. Users can query the TimeTree resource by providing two names of organisms (common or scientific) that can correspond to species or groups of species. The current TimeTree web resource (TimeTree2) contains timetrees reported from molecular clock analyses in 910 published studies and 17 341 species that span the diversity of life. TimeTree2 interprets complex and hierarchical data from these studies for each user query, which can be launched using an iPhone application, in addition to the website. Published time estimates are now readily accessible to the scientific community, K-12 and college educators, and the general public, without requiring knowledge of evolutionary nomenclature. TimeTree2 is accessible from the URL http://www.timetree.org, with an iPhone app available from iTunes (http://itunes.apple.com/us/app/timetree/id372842500?mt=8) and a YouTube tutorial (http://www.youtube.com/watch?v=CxmshZQciwo).

  13. Evaluating Fast Maximum Likelihood-Based Phylogenetic Programs Using Empirical Phylogenomic Data Sets

    Science.gov (United States)

    Zhou, Xiaofan; Shen, Xing-Xing; Hittinger, Chris Todd

    2018-01-01

    Abstract The sizes of the data matrices assembled to resolve branches of the tree of life have increased dramatically, motivating the development of programs for fast, yet accurate, inference. For example, several different fast programs have been developed in the very popular maximum likelihood framework, including RAxML/ExaML, PhyML, IQ-TREE, and FastTree. Although these programs are widely used, a systematic evaluation and comparison of their performance using empirical genome-scale data matrices has so far been lacking. To address this question, we evaluated these four programs on 19 empirical phylogenomic data sets with hundreds to thousands of genes and up to 200 taxa with respect to likelihood maximization, tree topology, and computational speed. For single-gene tree inference, we found that the more exhaustive and slower strategies (ten searches per alignment) outperformed faster strategies (one tree search per alignment) using RAxML, PhyML, or IQ-TREE. Interestingly, single-gene trees inferred by the three programs yielded comparable coalescent-based species tree estimations. For concatenation-based species tree inference, IQ-TREE consistently achieved the best-observed likelihoods for all data sets, and RAxML/ExaML was a close second. In contrast, PhyML often failed to complete concatenation-based analyses, whereas FastTree was the fastest but generated lower likelihood values and more dissimilar tree topologies in both types of analyses. Finally, data matrix properties, such as the number of taxa and the strength of phylogenetic signal, sometimes substantially influenced the programs’ relative performance. Our results provide real-world gene and species tree phylogenetic inference benchmarks to inform the design and execution of large-scale phylogenomic data analyses. PMID:29177474

  14. Estimating tree species diversity in the savannah using NDVI and woody canopy cover

    Science.gov (United States)

    Madonsela, Sabelo; Cho, Moses Azong; Ramoelo, Abel; Mutanga, Onisimo; Naidoo, Laven

    2018-04-01

    Remote sensing applications in biodiversity research often rely on the establishment of relationships between spectral information from the image and tree species diversity measured in the field. Most studies have used normalized difference vegetation index (NDVI) to estimate tree species diversity on the basis that it is sensitive to primary productivity which defines spatial variation in plant diversity. The NDVI signal is influenced by photosynthetically active vegetation which, in the savannah, includes woody canopy foliage and grasses. The question is whether the relationship between NDVI and tree species diversity in the savanna depends on the woody cover percentage. This study explored the relationship between woody canopy cover (WCC) and tree species diversity in the savannah woodland of southern Africa and also investigated whether there is a significant interaction between seasonal NDVI and WCC in the factorial model when estimating tree species diversity. To fulfil our aim, we followed stratified random sampling approach and surveyed tree species in 68 plots of 90 m × 90 m across the study area. Within each plot, all trees with diameter at breast height of >10 cm were sampled and Shannon index - a common measure of species diversity which considers both species richness and abundance - was used to quantify tree species diversity. We then extracted WCC in each plot from existing fractional woody cover product produced from Synthetic Aperture Radar (SAR) data. Factorial regression model was used to determine the interaction effect between NDVI and WCC when estimating tree species diversity. Results from regression analysis showed that (i) WCC has a highly significant relationship with tree species diversity (r2 = 0.21; p NDVI and WCC is not significant, however, the factorial model significantly reduced the error of prediction (RMSE = 0.47, p NDVI (RMSE = 0.49) or WCC (RMSE = 0.49) model during the senescence period. The result justifies our assertion

  15. Uranium mobility across annual growth rings in three deciduous tree species.

    Science.gov (United States)

    McHugh, Kelly C; Widom, Elisabeth; Spitz, Henry B; Wiles, Gregory C; Glover, Sam E

    2018-02-01

    Black walnut (Juglans nigra), slippery elm (Ulmus rubra), and white ash (Fraxinus americana) trees were evaluated as potential archives of past uranium (U) contamination. Like other metals, U mobility in annual growth rings of trees is dependent on the tree species. Uranium concentrations and isotopic compositions (masses 234, 235, 236, and 238) were analyzed by thermal ionization mass spectrometry to test the efficacy of using tree rings to retroactively monitor U pollution from the FFMPC, a U purification facility operating from 1951 to 1989. This study found non-natural U (depleted U and detectable 236 U) in growth rings of all three tree species that pre-dated the start of operations at FFMPC and compositional trends that did not correspond with known contamination events. Therefore, the annual growth rings of these tree species cannot be used to reliably monitor the chronology of U contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Application of objective provision tree to development of standard review plan for sodium-cooled fast reactor nuclear design

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Moo-Hoon; Suh, Namduk; Choi, Yongwon; Shin, Andong [Korea Institute of Nuclear Safety, Daejon (Korea, Republic of)

    2016-06-15

    A systematic methodology was developed for the standard review plan for sodium-cooled fast reactor nuclear design. The process is first to develop an objective provision tree of sodium-cooled fast reactor for the reactivity control safety function. The provision tree is generally developed by designer to confirm whether the design satisfies the defense-in-depth concept. Then applicability of the current standard review plan of nuclear design for light water reactor to sodium-cooled fast reactor was evaluated and complemented by the developed objective provision tree.

  17. Fast demographic traits promote high diversification rates of Amazonian trees

    NARCIS (Netherlands)

    Baker, T.R.; Pennington, R.T.; Magallon, S.; Gloor, E.; Laurance, W.F.; Alexiades, M.; Alvarez, E.; Araujo, de A.; Arets, E.J.M.M.

    2014-01-01

    The Amazon rain forest sustains the world's highest tree diversity, but it remains unclear why some clades of trees are hyperdiverse, whereas others are not. Using dated phylogenies, estimates of current species richness and trait and demographic data from a large network of forest plots, we show

  18. The natural abundance of 15N in litter and soil profiles under six temperate tree species: N cycling depends on tree species traits and site fertility

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Nilsson, Lars Ola; Schmidt, Inger Kappel

    2013-01-01

    We investigated the influence of tree species on the natural 15N abundance in forest stands under elevated ambient N deposition.We analysed δ15N in litter, the forest floor and three mineral soil horizons along with ecosystem N status variables at six sites planted three decades ago with five Eur...... to nitrate leaching or other N transformation processes....... species leached more nitrate.The δ15N pattern reflected tree species related traits affecting the N cycling as well as site fertility and former land use, and possibly differences in N leaching. The tree species δ15N patterns reflected fractionation caused by uptake of N through mycorrhiza rather than due...

  19. Mapping forest tree species over large areas with partially cloudy Landsat imagery

    Science.gov (United States)

    Turlej, K.; Radeloff, V.

    2017-12-01

    Forests provide numerous services to natural systems and humankind, but which services forest provide depends greatly on their tree species composition. That makes it important to track not only changes in forest extent, something that remote sensing excels in, but also to map tree species. The main goal of our work was to map tree species with Landsat imagery, and to identify how to maximize mapping accuracy by including partially cloudy imagery. Our study area covered one Landsat footprint (26/28) in Northern Wisconsin, USA, with temperate and boreal forests. We selected this area because it contains numerous tree species and variable forest composition providing an ideal study area to test the limits of Landsat data. We quantified how species-level classification accuracy was affected by a) the number of acquisitions, b) the seasonal distribution of observations, and c) the amount of cloud contamination. We classified a single year stack of Landsat-7, and -8 images data with a decision tree algorithm to generate a map of dominant tree species at the pixel- and stand-level. We obtained three important results. First, we achieved producer's accuracies in the range 70-80% and user's accuracies in range 80-90% for the most abundant tree species in our study area. Second, classification accuracy improved with more acquisitions, when observations were available from all seasons, and is the best when images with up to 40% cloud cover are included. Finally, classifications for pure stands were 10 to 30 percentage points better than those for mixed stands. We conclude that including partially cloudy Landsat imagery allows to map forest tree species with accuracies that were previously only possible for rare years with many cloud-free observations. Our approach thus provides important information for both forest management and science.

  20. Thematic and spatial resolutions affect model-based predictions of tree species distribution.

    Science.gov (United States)

    Liang, Yu; He, Hong S; Fraser, Jacob S; Wu, ZhiWei

    2013-01-01

    Subjective decisions of thematic and spatial resolutions in characterizing environmental heterogeneity may affect the characterizations of spatial pattern and the simulation of occurrence and rate of ecological processes, and in turn, model-based tree species distribution. Thus, this study quantified the importance of thematic and spatial resolutions, and their interaction in predictions of tree species distribution (quantified by species abundance). We investigated how model-predicted species abundances changed and whether tree species with different ecological traits (e.g., seed dispersal distance, competitive capacity) had different responses to varying thematic and spatial resolutions. We used the LANDIS forest landscape model to predict tree species distribution at the landscape scale and designed a series of scenarios with different thematic (different numbers of land types) and spatial resolutions combinations, and then statistically examined the differences of species abundance among these scenarios. Results showed that both thematic and spatial resolutions affected model-based predictions of species distribution, but thematic resolution had a greater effect. Species ecological traits affected the predictions. For species with moderate dispersal distance and relatively abundant seed sources, predicted abundance increased as thematic resolution increased. However, for species with long seeding distance or high shade tolerance, thematic resolution had an inverse effect on predicted abundance. When seed sources and dispersal distance were not limiting, the predicted species abundance increased with spatial resolution and vice versa. Results from this study may provide insights into the choice of thematic and spatial resolutions for model-based predictions of tree species distribution.

  1. Growing and marketing woody species to support pollinators: An emerging opportunity for forest, conservation, and native plant nurseries in the Northeastern United States

    Science.gov (United States)

    Kas Dumroese; Tara Luna

    2016-01-01

    The decline of insects that pollinate flowers is garnering more attention by land managers, policymakers, and the general public. Nursery managers who grow native trees, shrubs, and woody vines have a promising opportunity to showcase these species, marketing their contributions to pollinator health and other ecosystem services in urban and wild landscapes....

  2. Hydraulic Function in Australian Tree Species during Drought-Induced Mortality

    Science.gov (United States)

    Tissue, D.; Maier, C.; Creek, D.; Choat, B.

    2016-12-01

    Drought induced tree mortality and decline are key issues facing forest ecology and management. Here, we primarily investigated the hydraulic limitations underpinning drought-induced mortality in three Australian tree species. Using field-based large rainout shelters, three angiosperm species (Casuarina cunninghamiana, Eucalyptus sideroxylon, Eucalyptus tereticornis) were subjected to two successive drought and recovery cycles, prior to a subsequent long and extreme drought to mortality; total duration of experiment was 2.5 years. Leaf gas exchange, leaf and stem hydraulics, and carbon reserves were monitored during the experiment. Trees died as a result of failure in the hydraulic transport system, primarily related to water stress induced embolism. Stomatal closure occurred prior to the induction of significant embolism in the stem xylem of all species. Nonetheless, trees suffered a rapid decline in xylem water potential and increase in embolism during the severe drought treatment. Trees died at water potentials causing greater than 90% loss of hydraulic conductivity in the stem, providing support for the theory that lethal water potential is correlated with complete loss of hydraulic function in the stem xylem of angiosperms.

  3. Lidar-based individual tree species classification using convolutional neural network

    Science.gov (United States)

    Mizoguchi, Tomohiro; Ishii, Akira; Nakamura, Hiroyuki; Inoue, Tsuyoshi; Takamatsu, Hisashi

    2017-06-01

    Terrestrial lidar is commonly used for detailed documentation in the field of forest inventory investigation. Recent improvements of point cloud processing techniques enabled efficient and precise computation of an individual tree shape parameters, such as breast-height diameter, height, and volume. However, tree species are manually specified by skilled workers to date. Previous works for automatic tree species classification mainly focused on aerial or satellite images, and few works have been reported for classification techniques using ground-based sensor data. Several candidate sensors can be considered for classification, such as RGB or multi/hyper spectral cameras. Above all candidates, we use terrestrial lidar because it can obtain high resolution point cloud in the dark forest. We selected bark texture for the classification criteria, since they clearly represent unique characteristics of each tree and do not change their appearance under seasonable variation and aged deterioration. In this paper, we propose a new method for automatic individual tree species classification based on terrestrial lidar using Convolutional Neural Network (CNN). The key component is the creation step of a depth image which well describe the characteristics of each species from a point cloud. We focus on Japanese cedar and cypress which cover the large part of domestic forest. Our experimental results demonstrate the effectiveness of our proposed method.

  4. Changes in carbon pool and stand structure of a native subtropical mangrove forest after inter-planting with exotic species Sonneratia apetala.

    Science.gov (United States)

    Lu, Weizhi; Yang, Shengchang; Chen, Luzhen; Wang, Wenqing; Du, Xiaona; Wang, Canmou; Ma, Yan; Lin, Guangxuan; Lin, Guanghui

    2014-01-01

    In this study, we compared stand structure, biomass and soil carbon pools, and litterfall production between a mixed mangrove forest consisting of Aegiceras corniculatum inter-planted with the exotic Sonneratia apetala and a native monospecific forest dominated by A. corniculatum in the intertidal area of Zhanjiang, Guangdong Province, southeast China. The goal of this study was to test the hypothesis that inter-planting fast growing exotic mangrove S. apetala into subtropical native mangrove forests will significantly increase C sequestration. Although the tree heights and basal diameters of S. apetala were significantly higher than those of A. corniculatum, the density of the 12-year-old S. apetala trees in the mixed forest was much smaller than that of A. corniculatum in the monospecific forest. In contrast to several previous studies on S. apetala forests planted directly on mangrove-free mudflats, the mixed mangrove forest showed no significant difference in either standing biomass or soil carbon pools from the native monospecific mangrove forest (p = 0.294 and 0.073, respectively) twelve years after inter-planting with S. apetala. Moreover, carbon cycling was likely speeded up after inter-planting S. apetala due to higher litterfall input and lower C/N ratio. Thus, inter-planting fast-growing S. apetala into native mangrove forest is not an effective way to increase carbon sequestration in this subtropical mangrove forest. Given that exotic plant species may exert negative impact on native mangrove species and related epifauna, this fast-growing mangrove species is not suitable for mangrove plantation projects aiming mainly at enhancing carbon sequestration.

  5. Fast and accurate methods for phylogenomic analyses

    Directory of Open Access Journals (Sweden)

    Warnow Tandy

    2011-10-01

    Full Text Available Abstract Background Species phylogenies are not estimated directly, but rather through phylogenetic analyses of different gene datasets. However, true gene trees can differ from the true species tree (and hence from one another due to biological processes such as horizontal gene transfer, incomplete lineage sorting, and gene duplication and loss, so that no single gene tree is a reliable estimate of the species tree. Several methods have been developed to estimate species trees from estimated gene trees, differing according to the specific algorithmic technique used and the biological model used to explain differences between species and gene trees. Relatively little is known about the relative performance of these methods. Results We report on a study evaluating several different methods for estimating species trees from sequence datasets, simulating sequence evolution under a complex model including indels (insertions and deletions, substitutions, and incomplete lineage sorting. The most important finding of our study is that some fast and simple methods are nearly as accurate as the most accurate methods, which employ sophisticated statistical methods and are computationally quite intensive. We also observe that methods that explicitly consider errors in the estimated gene trees produce more accurate trees than methods that assume the estimated gene trees are correct. Conclusions Our study shows that highly accurate estimations of species trees are achievable, even when gene trees differ from each other and from the species tree, and that these estimations can be obtained using fairly simple and computationally tractable methods.

  6. Anchoring quartet-based phylogenetic distances and applications to species tree reconstruction.

    Science.gov (United States)

    Sayyari, Erfan; Mirarab, Siavash

    2016-11-11

    Inferring species trees from gene trees using the coalescent-based summary methods has been the subject of much attention, yet new scalable and accurate methods are needed. We introduce DISTIQUE, a new statistically consistent summary method for inferring species trees from gene trees under the coalescent model. We generalize our results to arbitrary phylogenetic inference problems; we show that two arbitrarily chosen leaves, called anchors, can be used to estimate relative distances between all other pairs of leaves by inferring relevant quartet trees. This results in a family of distance-based tree inference methods, with running times ranging between quadratic to quartic in the number of leaves. We show in simulated studies that DISTIQUE has comparable accuracy to leading coalescent-based summary methods and reduced running times.

  7. Tree species diversity in the Eastern Ghats of northern Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    M. Tarakeswara Naidu

    2015-06-01

    Full Text Available The present study was conducted to analyze tree species diversity in the tropical forests of the Eastern Ghats of northern Andhra Pradesh, India.  A total of 270 species of trees (≥15cm girth at breast height pertaining to 177 genera belonging to 55 families were recorded.  Among the 270 species, 141 species were observed to be common, 78 were occasional and 51 species were rare in the study area.  Fabaceae was the dominant family with 33 species followed by Rubiaceae with 15 species and Malvaceae, Moraceae and Phyllanthaceae with 13 species each.  The genera with the highest number of species include Ficus (12 species, Diospyros (8 species, Albizia and Grewia (6 species each, Acacia and Bauhinia (5 species each.  Forty-five percent of the species were indigenous. This illustrates the diversity of the tree species in the studied area of the Eastern Ghats and also emphasizes the need for their conservation. 

  8. Phylogenetic Structure of Tree Species across Different Life Stages from Seedlings to Canopy Trees in a Subtropical Evergreen Broad-Leaved Forest.

    Science.gov (United States)

    Jin, Yi; Qian, Hong; Yu, Mingjian

    2015-01-01

    Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from seedlings to canopy trees, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of tree species from seedlings, saplings, treelets to canopy trees; we compare the phylogenetic turnover (measured as βNRI) between canopy trees and seedlings in forest understory with that between canopy trees and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy trees, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy trees and seedlings in forest understory is lower than that between canopy trees and seedlings in forest gaps. We conclude that tree species tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as tree stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved tree species whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate.

  9. Effect of temperate climate tree species on gross ammonification, gross nitrification and N2O formation

    Science.gov (United States)

    Brüggemann, N.; Rosenkranz, P.; Papen, H.; Butterbach-Bahl, K.

    2003-04-01

    Microbial nitrogen turnover processes in the soil, like ammonification, nitrification and denitrification, play an important role in the formation of nitrous oxide (N2O): (i) ammonification, because it releases nitrogen from organic material in the form of ammonium (NH4+), which in turn can serve as substrate for nitrification; (ii) nitrification itself (i.e. the turnover of NH4+ to nitrate, NO3-), during which nitric oxide (NO) and N2O can be released as by-products at varying ratios; (iii) denitrification, in which NO3- serves as electron acceptor and is converted to molecular nitrogen (N2) via NO and N2O as intermediates, that can also be partially lost to the atmosphere. Temperate forest soils are a substantial source of atmospheric N2O contributing up to 10% to the total atmospheric N2O budget. However, this figure is afflicted with a huge uncertainty due to a number of factors governing the soil N2O formation, consumption, release and uptake, which are not fully understood at present. To one of these factors belongs the influence of the tree species on nitrogen turnover processes in the soil and the formation of N trace gases related with them. The aim of the present work was to analyse this tree species effect for the temperate climate region. For this purpose the effect of five different temperate tree species, having the same age and growing on the same soil in direct vicinity to each other, on gross ammonification and gross nitrification as well as on N2O formation was investigated. The trees (common beech, Fagus sylvatica; pedunculate oak, Quercus robur; Norway spruce, Picea abies; Japanese larch, Larix leptolepis; mountain pine, Pinus mugo) were part of a species trial in Western Jutland, Denmark, established in 1965 on a former sandy heathland. Samples from the soil under these five tree species were taken in spring and in summer 2002, respectively, differentiating between organic layer and mineral soil. The gross rates of ammonification as well of

  10. Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest.

    Science.gov (United States)

    Mendivelso, Hooz A; Camarero, J Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.

  11. Trees for future forests

    DEFF Research Database (Denmark)

    Lobo, Albin

    Climate change creates new challenges in forest management. The increase in temperature may in the long run be beneficial for the forests in the northern latitudes, but the high rate at which climate change is predicted to proceed will make adaptation difficult because trees are long living sessile...... organisms. The aim of the present thesis is therefore to explore genetic resilience and phenotypic plasticity mechanisms that allows trees to adapt and evolve with changing climates. The thesis focus on the abiotic factors associated with climate change, especially raised temperatures and lack...... age of these tree species and the uncertainty around the pace and effect of climate, it remains an open question if the native populations can respond fast enough. Phenotypic plasticity through epigenetic regulation of spring phenology is found to be present in a tree species which might act...

  12. Simulating carbon dioxide exchange rates of deciduous tree species: evidence for a general pattern in biochemical changes and water stress response.

    Science.gov (United States)

    Reynolds, Robert F; Bauerle, William L; Wang, Ying

    2009-09-01

    Deciduous trees have a seasonal carbon dioxide exchange pattern that is attributed to changes in leaf biochemical properties. However, it is not known if the pattern in leaf biochemical properties - maximum Rubisco carboxylation (V(cmax)) and electron transport (J(max)) - differ between species. This study explored whether a general pattern of changes in V(cmax), J(max), and a standardized soil moisture response accounted for carbon dioxide exchange of deciduous trees throughout the growing season. The model MAESTRA was used to examine V(cmax) and J(max) of leaves of five deciduous trees, Acer rubrum 'Summer Red', Betula nigra, Quercus nuttallii, Quercus phellos and Paulownia elongata, and their response to soil moisture. MAESTRA was parameterized using data from in situ measurements on organs. Linking the changes in biochemical properties of leaves to the whole tree, MAESTRA integrated the general pattern in V(cmax) and J(max) from gas exchange parameters of leaves with a standardized soil moisture response to describe carbon dioxide exchange throughout the growing season. The model estimates were tested against measurements made on the five species under both irrigated and water-stressed conditions. Measurements and modelling demonstrate that the seasonal pattern of biochemical activity in leaves and soil moisture response can be parameterized with straightforward general relationships. Over the course of the season, differences in carbon exchange between measured and modelled values were within 6-12 % under well-watered conditions and 2-25 % under water stress conditions. Hence, a generalized seasonal pattern in the leaf-level physiological change of V(cmax) and J(max), and a standardized response to soil moisture was sufficient to parameterize carbon dioxide exchange for large-scale evaluations. Simplification in parameterization of the seasonal pattern of leaf biochemical activity and soil moisture response of deciduous forest species is demonstrated. This

  13. Predicting tree biomass growth in the temperate-boreal ecotone: is tree size, age, competition or climate response most important?

    Science.gov (United States)

    Foster, Jane R.; Finley, Andrew O.; D'Amato, Anthony W.; Bradford, John B.; Banerjee, Sudipto

    2016-01-01

    As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2and thereby slow rising CO2 concentrations. Forests’ ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals’ size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species likeAcer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92–95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth

  14. Predicting tree biomass growth in the temperate-boreal ecotone: Is tree size, age, competition, or climate response most important?

    Science.gov (United States)

    Foster, Jane R; Finley, Andrew O; D'Amato, Anthony W; Bradford, John B; Banerjee, Sudipto

    2016-06-01

    As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2 and thereby slow rising CO2 concentrations. Forests' ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals' size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species like Acer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92-95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth responses

  15. [Effects of sampling plot number on tree species distribution prediction under climate change].

    Science.gov (United States)

    Liang, Yu; He, Hong-Shi; Wu, Zhi-Wei; Li, Xiao-Na; Luo, Xu

    2013-05-01

    Based on the neutral landscapes under different degrees of landscape fragmentation, this paper studied the effects of sampling plot number on the prediction of tree species distribution at landscape scale under climate change. The tree species distribution was predicted by the coupled modeling approach which linked an ecosystem process model with a forest landscape model, and three contingent scenarios and one reference scenario of sampling plot numbers were assumed. The differences between the three scenarios and the reference scenario under different degrees of landscape fragmentation were tested. The results indicated that the effects of sampling plot number on the prediction of tree species distribution depended on the tree species life history attributes. For the generalist species, the prediction of their distribution at landscape scale needed more plots. Except for the extreme specialist, landscape fragmentation degree also affected the effects of sampling plot number on the prediction. With the increase of simulation period, the effects of sampling plot number on the prediction of tree species distribution at landscape scale could be changed. For generalist species, more plots are needed for the long-term simulation.

  16. Diagnostics of Tree Diseases Caused by Phytophthora austrocedri Species.

    Science.gov (United States)

    Mulholland, Vincent; Elliot, Matthew; Green, Sarah

    2015-01-01

    We present methods for the detection and quantification of four Phytophthora species which are pathogenic on trees; Phytophthora ramorum, Phytophthora kernoviae, Phytophthora lateralis, and Phytophthora austrocedri. Nucleic acid extraction methods are presented for phloem tissue from trees, soil, and pure cultures on agar plates. Real-time PCR methods are presented and include primer and probe sets for each species, general advice on real-time PCR setup and data analysis. A method for sequence-based identification, useful for pure cultures, is also included.

  17. Determination of incoming solar radiation in major tree species in Turkey.

    Science.gov (United States)

    Yilmaz, Osman Yalcin; Sevgi, Orhan; Koc, Ayhan

    2012-07-01

    Light requirements and spatial distribution of major forest tree species in Turkey hasn't been analyzed yet. Continuous surface solar radiation data, especially at mountainous-forested areas, are needed to put forward this relationship between forest tree species and solar radiation. To achieve this, GIS-based modeling of solar radiation is one of the methods used in rangelands to estimate continuous surface solar radiation. Therefore, mean monthly and annual total global solar radiation maps of whole Turkey were computed spatially using GRASS GIS software "r.sun" model under clear-sky (cloudless) conditions. 147498 pure forest stand point-based data were used in the study for calculating mean global solar radiation values of all the major forest tree species of Turkey. Beech had the lowest annual mean total global solar radiation value of 1654.87 kWh m(-2), whereas juniper had the highest value of 1928.89 kWh m(-2). The rank order of tree species according to the mean monthly and annual total global solar radiation values, using a confidence level of p solar radiation values of sites and light requirements of forest trees ranked similarly.

  18. Willow trees from heavy metals phytoextraction as energy crops

    International Nuclear Information System (INIS)

    Šyc, Michal; Pohořelý, Michael; Kameníková, Petra; Habart, Jan; Svoboda, Karel; Punčochář, Miroslav

    2012-01-01

    Phytoextraction ability of some fast growing plant species leads to the idea of connecting biomass production with soil remediation of contaminated industrial zones and regions. This biomass will contain significant amount of heavy metals and its energetic utilization has to be considered carefully to minimize negative environmental impacts. This study was focused on potential disposal methods of willow trees contaminated by heavy metals (Cd, Cu, Pb, Zn) with the emphasis on energetic utilization of biomass. Composting seems to be suitable pre-treatment method resulting in decrease of heavy metals leachability and biomass weight reduction. The possibility of willow trees application for energetic purposes was investigated and consequently incineration tests of willow trees samples in fluidized bed reactor were realized. Distribution of selected heavy metals in different ash fractions and treatment methods of produced ashes were studied as well. -- Highlights: ► Composting is an appropriate pre-treatment method for phytoextraction crops. ► Fluidized bed combustion is suitable disposal method of phytoextraction crops. ► Ashes from phytoextraction crops combustion cannot be used as fertilizers.

  19. Adaptability to climate change in forestry species: drought effects on growth and wood anatomy of ponderosa pines growing at different competition levels

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M. E.; Gyenge, J. E.; Urquiza, M. M.; Varela, S.

    2012-11-01

    More stressful conditions are expected due to climatic change in several regions, including Patagonia, South-America. In this region, there are no studies about the impact of severe drought events on growth and wood characteristics of the most planted forestry species, Pinus ponderosa (Doug. ex-Laws). The objective of this study was to quantify the effect of a severe drought event on annual stem growth and functional wood anatomy of pines growing at different plantation densities aiming to understand how management practices can help to increase their adaptability to climate change. Growth magnitude and period, specific hydraulic conductivity, and anatomical traits (early- and late wood proportion, lumen diameter, cell-wall thickness, tracheid length and bordered pit dimensions) were measured in the ring 2008-2009, which was formed during drought conditions. This drought event decreased annual stem growth by 30-38% and 58-65% respect to previous mean growth, in open vs. closed stand trees, respectively, indicating a higher sensitivity of the latter, which is opposite to reports from the same species growing in managed native forests in USA. Some wood anatomical variables did differ in more water stressed trees (lower cell wall thickness of early wood cells and higher proportion of small-lumen cells in late wood), which in turn did not affect wood function (hydraulic conductivity and resistance to implosion). Other anatomical variables (tracheid length, pit dimensions, early- and late wood proportion, lumen diameter of early wood cells) did not differ between tree sizes and plantation density. The results suggest that severe drought affects differentially the amount but not the function and quality of formed wood in ponderosa pine growing at different competition levels. (Author) 41 refs.

  20. FMECA application to Rainfall Hazard prevention in olive trees growings

    Science.gov (United States)

    Buendia-Buendía, F. S.; Bermudez, R.; Tarquis, A. M.; Andina, D.

    2010-05-01

    The FMECA (Failure Mode Effects and Criticality Analysis) is a broadly extended System Safety tool applied in industries as Aerospace in order to prevent hazards. This methodology studies the different failure modes of a system and try to mitigate them in a systematic procedure. In this paper this tool is applied in order to mitigate economical impact hazards derived from Rainfalls to olive trees growing in Granada (Spain), understanding hazard from the System Safety perspective (Any real or potential condition that can cause injury, illness, or death to personnel; damage to or loss of a system, equipment or property; or damage to the environment). The work includes a brief introduction to the System Safety and FMECA methodologies, applying then these concepts to analyze the Olive trees as a system and identify the hazards during the different stages of the whole life cycle plant production.

  1. Trees, Shrubs, and Woody Vines of the Bluff Experimental Forest, Warren County, Mississippi

    Science.gov (United States)

    Robert L. Johnson; Elbert L. Little

    1967-01-01

    Nearly 100 species of trees, shrubs, and woody vines grow naturally on the 450-acre Bluff Experimental Forest in west-central Mississippi. This publication lists the plants and provides information on silvical characteristics of the tree species.

  2. Compartmentalization: a conceptual framework for understanding how trees grow and defend themselves

    Science.gov (United States)

    Alex L. Shigo

    1984-01-01

    The purpose of this chapter is to describe a conceptual framework for understanding how trees grow and how they and other perennial plants defend themselves. The concept of compartmentalization has developed over many years, a synthesis of ideas from a number of investigators. It is derived from detailed studies of the gross morphology and cellular anatomy of the wood...

  3. Widespread Discordance of Gene Trees with Species Tree inDrosophila: Evidence for Incomplete Lineage Sorting

    Energy Technology Data Exchange (ETDEWEB)

    Pollard, Daniel A.; Iyer, Venky N.; Moses, Alan M.; Eisen,Michael B.

    2006-08-28

    The phylogenetic relationship of the now fully sequencedspecies Drosophila erecta and D. yakuba with respect to the D.melanogaster species complex has been a subject of controversy. All threepossible groupings of the species have been reported in the past, thoughrecent multi-gene studies suggest that D. erecta and D. yakuba are sisterspecies. Using the whole genomes of each of these species as well as thefour other fully sequenced species in the subgenus Sophophora, we set outto investigate the placement of D. erecta and D. yakuba in the D.melanogaster species group and to understand the cause of the pastincongruence. Though we find that the phylogeny grouping D. erecta and D.yakuba together is the best supported, we also find widespreadincongruence in nucleotide and amino acid substitutions, insertions anddeletions, and gene trees. The time inferred to span the two keyspeciation events is short enough that under the coalescent model, theincongruence could be the result of incomplete lineage sorting.Consistent with the lineage-sorting hypothesis, substitutions supportingthe same tree were spatially clustered. Support for the different treeswas found to be linked to recombination such that adjacent genes supportthe same tree most often in regions of low recombination andsubstitutions supporting the same tree are most enriched roughly on thesame scale as linkage disequilibrium, also consistent with lineagesorting. The incongruence was found to be statistically significant androbust to model and species choice. No systematic biases were found. Weconclude that phylogenetic incongruence in the D. melanogaster speciescomplex is the result, at least in part, of incomplete lineage sorting.Incomplete lineage sorting will likely cause phylogenetic incongruence inmany comparative genomics datasets. Methods to infer the correct speciestree, the history of every base in the genome, and comparative methodsthat control for and/or utilize this information will be

  4. Effect of liquid nitrogen storage on seed germination of 51 tree species

    Science.gov (United States)

    Jill R. Barbour; Bernard R. Parresol

    2003-01-01

    Two liquid nitrogen storage experiments were performed on 51 tree species. In experiment 1, seeds of 9western tree species were placed in a liquid nitrogen tank for 3 time periods: 24 hours, 4 weeks, and 222 days. A corresponding control sample accompanied each treatment. For three species,Calocedrus decurrens, Pinus jefferyi, and ...

  5. Fast and frugal trees: translating population-based pharmacogenomics to medication prioritization

    NARCIS (Netherlands)

    Rooij, T. van; Roederer, M.; Wareham, H.T.; Rooij, I.J.E.I. van; McLeod, H.L.; Marsh, S.

    2015-01-01

    Aim: Fast and frugal decision trees (FFTs) can simplify clinical decision making by providing a heuristic approach to contextual guidance. We wanted to use FFTs for pharmacogenomic knowledge translation at point-of-care. Materials & Methods: The Pharmacogenomics for Every Nation Initiative (PGENI),

  6. Microsatellite markers in Paulownia kawakamii (Scrophulariaceae) and cross-amplification in other Paulownia species.

    Science.gov (United States)

    Wang, H W; Duan, J M; Zhang, P; Cheng, Y Q; Wu, J W; Wang, G Z

    2013-09-19

    Paulownia kawakamii is a fast-growing timber tree. In this study, 21 primer sets were developed using an enriched genomic library. The genetic diversity was measured in one P. kawakamii population. The number of alleles per locus ranged from 2 to 19. The observed and expected heterozygosities varied from 0.158 to 0.842 (mean = 0.421) and from 0.376 to 0.952 (mean = 0.771), respectively. All 21 loci were also polymorphic in closely related species (P. tomentosa, P. elongata, and P. fortunei). The described markers will be useful in future population genetic studies and molecular breeding of these Paulownia species.

  7. Tree species distribution in temperate forests is more influenced by soil than by climate.

    Science.gov (United States)

    Walthert, Lorenz; Meier, Eliane Seraina

    2017-11-01

    Knowledge of the ecological requirements determining tree species distributions is a precondition for sustainable forest management. At present, the abiotic requirements and the relative importance of the different abiotic factors are still unclear for many temperate tree species. We therefore investigated the relative importance of climatic and edaphic factors for the abundance of 12 temperate tree species along environmental gradients. Our investigations are based on data from 1,075 forest stands across Switzerland including the cold-induced tree line of all studied species and the drought-induced range boundaries of several species. Four climatic and four edaphic predictors represented the important growth factors temperature, water supply, nutrient availability, and soil aeration. The climatic predictors were derived from the meteorological network of MeteoSwiss, and the edaphic predictors were available from soil profiles. Species cover abundances were recorded in field surveys. The explanatory power of the predictors was assessed by variation partitioning analyses with generalized linear models. For six of the 12 species, edaphic predictors were more important than climatic predictors in shaping species distribution. Over all species, abundances depended mainly on nutrient availability, followed by temperature, water supply, and soil aeration. The often co-occurring species responded similar to these growth factors. Drought turned out to be a determinant of the lower range boundary for some species. We conclude that over all 12 studied tree species, soil properties were more important than climate variables in shaping tree species distribution. The inclusion of appropriate soil variables in species distribution models allowed to better explain species' ecological niches. Moreover, our study revealed that the ecological requirements of tree species assessed in local field studies and in experiments are valid at larger scales across Switzerland.

  8. Inferring duplications, losses, transfers and incomplete lineage sorting with nonbinary species trees.

    Science.gov (United States)

    Stolzer, Maureen; Lai, Han; Xu, Minli; Sathaye, Deepa; Vernot, Benjamin; Durand, Dannie

    2012-09-15

    Gene duplication (D), transfer (T), loss (L) and incomplete lineage sorting (I) are crucial to the evolution of gene families and the emergence of novel functions. The history of these events can be inferred via comparison of gene and species trees, a process called reconciliation, yet current reconciliation algorithms model only a subset of these evolutionary processes. We present an algorithm to reconcile a binary gene tree with a nonbinary species tree under a DTLI parsimony criterion. This is the first reconciliation algorithm to capture all four evolutionary processes driving tree incongruence and the first to reconcile non-binary species trees with a transfer model. Our algorithm infers all optimal solutions and reports complete, temporally feasible event histories, giving the gene and species lineages in which each event occurred. It is fixed-parameter tractable, with polytime complexity when the maximum species outdegree is fixed. Application of our algorithms to prokaryotic and eukaryotic data show that use of an incomplete event model has substantial impact on the events inferred and resulting biological conclusions. Our algorithms have been implemented in Notung, a freely available phylogenetic reconciliation software package, available at http://www.cs.cmu.edu/~durand/Notung. mstolzer@andrew.cmu.edu.

  9. Predicting abundance of 80 tree species following climate change in the Eastern United States

    Science.gov (United States)

    Louis R. Iverson; Anantha M. Prasad; Anantha M. Prasad

    1998-01-01

    Projected climate warming will potentially have profound effects on the earth?s biota, including a large redistribution of tree species. We developed models to evaluate potential shifts for 80 individual tree species in the eastern United States. First, environmental factors associated with current ranges of tree species were assessed using geographic information...

  10. Geographical range and local abundance of tree species in China.

    Directory of Open Access Journals (Sweden)

    Haibao Ren

    Full Text Available Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1 whether locally abundant species tend to be geographically widespread; 2 whether species are more abundant towards their range-centers; and 3 how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20-25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km(2, and >90% of 651 species had ranges >10(5 km(2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species' abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges.

  11. Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest.

    Directory of Open Access Journals (Sweden)

    Hooz A Mendivelso

    Full Text Available A seasonal period of water deficit characterizes tropical dry forests (TDFs. There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.

  12. Differential Growth Responses to Water Balance of Coexisting Deciduous Tree Species Are Linked to Wood Density in a Bolivian Tropical Dry Forest

    Science.gov (United States)

    Mendivelso, Hooz A.; Camarero, J. Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability. PMID:24116001

  13. How fast do eels grow

    International Nuclear Information System (INIS)

    Hansen, H.J.M.

    1988-01-01

    Not so very much about the growth pattern of the eel is known yet. Eels move about nearly all the time. They are thus very difficult to follow and we do not, for examble, yet know how long it actually takes for them to grow to maturity in the wild. So far, a macroscopic analysis of the number of bright and dark areas (growth rings) in the 'earstones' has been used to determine eel age, but this method was recently challenged. Use of radioisotopes has been suggested previously for this purpose. For this present study the rare earth elements, europium-152 and europium-155 are used. When incubated in artificial sea water, a satisfactory final radioactive label was achieved. Two experiments were planned in collaboration with the Swedish Environmental Protection Agency. 2000 Elvers were set out in 1982, in the cooling water outlet of the Oskarshamn nuclear power plant, each marked with europium-155. In 1984 another 10 000 elvers labelled with europium-152 were set out under similar conditions. The idea was mainly to see how fast the eels would grow, and to compare their known age with that determined by examining the earstones. Results showed that there was no clear-cut correlation between actual eel age and the biological age determination used so far. During four years, only 10 of the original 1300 eels were recaptured. It is thus hard to say anything definite from our results on the viability of setting out elvers in the environment

  14. Ecological and economic determinants of invasive tree species on Alabama forestland

    Science.gov (United States)

    Anwar Hussain; Changyou Sun; Xiaoping Zhou; Ian A. Munn

    2008-01-01

    The spread of invasive tree species has caused increasing harm to the environment. This study was motivated by the considerations that earlier studies generally ignored the role of economic factors related to the occurrence and abundance of invasive species, and empirical analyses of invasive trees on forestland have been inadequate. We assessed the impact of...

  15. Systematic adaptive cluster sampling for the assessment of rare tree species in Nepal

    NARCIS (Netherlands)

    Acharya, B.; Bhattarai, G.; Gier, de A.; Stein, A.

    2000-01-01

    Sampling to assess rare tree species poses methodic problems, because they may cluster and many plots with no such trees are to be expected. We used systematic adaptive cluster sampling (SACS) to sample three rare tree species in a forest area of about 40 ha in Nepal. We checked its applicability

  16. Wood density variation in Gmelina arborea trees using X-ray densitometry

    International Nuclear Information System (INIS)

    Roque, Roger Moya; Tomazello, Mario

    2005-01-01

    The wood density constitutes the main wood quality parameter by its relationship with anatomical, physical and chemical properties and wood utilization. The modern and accurate methods - like X-ray densitometry - are applied to determine the density spatial distribution in wood sections and pith-bark direction. On the other hand, emphasis to wood utilization from fast growing plantations, like Gmelina arborea in Costa Rica, has been done. The objectives of this study were to determinate the influence of 2 climatic conditions of Costa Rica on radial wood density variation of gmelina trees form fast growing plantations using the X-ray densitometry method. Wood samples were cut at DBH of gmelina trees and transversal thin laths were selected at north-south direction and conditioned at 12% moisture content equilibrium and X-rayed. The radiographic films were revealed and scanned a 256 gray scale with 1000 dpi resolution and the intra tree-ring density were determined by CRAD and CERD software. The results demonstrated that the climatic and forest management affects the wood density variability and the distinctness of tree-ring boundaries of gmelina trees, as well as, the applicability of X-ray densitometry in wood quality analysis. (author)

  17. Biomass models to estimate carbon stocks for hardwood tree species

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Peinado, R.; Montero, G.; Rio, M. del

    2012-11-01

    To estimate forest carbon pools from forest inventories it is necessary to have biomass models or biomass expansion factors. In this study, tree biomass models were developed for the main hardwood forest species in Spain: Alnus glutinosa, Castanea sativa, Ceratonia siliqua, Eucalyptus globulus, Fagus sylvatica, Fraxinus angustifolia, Olea europaea var. sylvestris, Populus x euramericana, Quercus canariensis, Quercus faginea, Quercus ilex, Quercus pyrenaica and Quercus suber. Different tree biomass components were considered: stem with bark, branches of different sizes, above and belowground biomass. For each species, a system of equations was fitted using seemingly unrelated regression, fulfilling the additivity property between biomass components. Diameter and total height were explored as independent variables. All models included tree diameter whereas for the majority of species, total height was only considered in the stem biomass models and in some of the branch models. The comparison of the new biomass models with previous models fitted separately for each tree component indicated an improvement in the accuracy of the models. A mean reduction of 20% in the root mean square error and a mean increase in the model efficiency of 7% in comparison with recently published models. So, the fitted models allow estimating more accurately the biomass stock in hardwood species from the Spanish National Forest Inventory data. (Author) 45 refs.

  18. Species-specific associations between overstory and understory tree species in a semideciduous tropical forest

    Directory of Open Access Journals (Sweden)

    Flaviana Maluf Souza

    2015-03-01

    Full Text Available We investigated the occurrence of associations between overstory and understory tree species in a semideciduous tropical forest. We identified and measured all trees of nine canopy species with diameter at breast height ≥4.8 cm in a 10.24 ha plot and recorded all individuals beneath their canopies ("understory individuals" within the same diameter class. The total density of understory individuals did not significantly differ under different overstory species. One overstory species (Ceiba speciosa showed higher understory species richness compared with five other species. There was a strong positive association between three overstory species (Esenbeckia leiocarpa, Savia dictyocarpa, and C. speciosa and the density of seven understory species (Balfourodendron riedelianum, Chrysophyllum gonocarpum, E. leiocarpa, Holocalyx balansae, Machaerium stipitatum, Rhaminidium elaeocarpum, and S. dictyocarpa. These results probably reflect the outcome of a complex set of interactions including facilitation and competition, and further studies are necessary to better understand the magnitude and type of the effects of individual overstory species on understory species. The occurrence of species-specific associations shown here reinforces the importance of non-random processes in structuring plant communities and suggest that the influence of overstory species on understory species in high-diversity forests may be more significant than previously thought.

  19. Ozone air pollution effects on tree-ring growth,{delta}{sup 13}C, visible foliar injury and leaf gas exchange in three ozone-sensitive woody plant species

    Energy Technology Data Exchange (ETDEWEB)

    Novak, K. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland); Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Saurer, M. [Paul Scherrer Inst. Villigen (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Skelly, J.M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Plant Pathology; Krauchi, N.; Schaub, M. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland)

    2007-07-15

    Species specific plant responses to tropospheric ozone pollution depend on a range of morphological, biochemical and physiological characteristics as well as environmental factors. The effects of ambient tropospheric ozone on annual tree-ring growth, {delta}{sup 13} C in the rings, leaf gas exchange and ozone-induced visible foliar injury in three ozone-sensitive woody plant species in southern Switzerland were assessed during the 2001 and 2002 growing seasons. Seedlings of Populus nigra L., Viburnum lantana L. and Fraxinus excelsior L. were exposed to charcoal-filtered air and non-filtered air in open-top chambers, and to ambient air (AA) in open plots. The objective was to determine if a relationship exists between measurable ozone-induced effects at the leaf level and subsequent changes in annual tree-ring growth and {delta} {sup 13} C signatures. The visible foliar injury, early leaf senescence and premature leaf loss in all species was attributed to the ambient ozone exposures in the region. Ozone had pronounced negative effects on net photosynthesis and stomatal conductance in all species in 2002 and in V. lantana and F. excelsior in 2001. Water-use efficiency decreased and intercellular carbon dioxide concentrations increased in all species in response to ozone in 2002 only. The width and {delta}{sup 13} C of the 2001 and 2002 growth rings were measured for all species at the end of the 2002 growing season. Significant ozone-induced effects at the leaf level did not correspond to reduced tree-ring growth or increased {delta}{sup 13} C in all species, suggesting that the timing of ozone exposure and extent of leaf-level responses may be relevant in determining the sensitivity of tree productivity to ozone exposure. 48 refs., 4 tabs., 2 figs.

  20. PhySortR: a fast, flexible tool for sorting phylogenetic trees in R.

    Science.gov (United States)

    Stephens, Timothy G; Bhattacharya, Debashish; Ragan, Mark A; Chan, Cheong Xin

    2016-01-01

    A frequent bottleneck in interpreting phylogenomic output is the need to screen often thousands of trees for features of interest, particularly robust clades of specific taxa, as evidence of monophyletic relationship and/or reticulated evolution. Here we present PhySortR, a fast, flexible R package for classifying phylogenetic trees. Unlike existing utilities, PhySortR allows for identification of both exclusive and non-exclusive clades uniting the target taxa based on tip labels (i.e., leaves) on a tree, with customisable options to assess clades within the context of the whole tree. Using simulated and empirical datasets, we demonstrate the potential and scalability of PhySortR in analysis of thousands of phylogenetic trees without a priori assumption of tree-rooting, and in yielding readily interpretable trees that unambiguously satisfy the query. PhySortR is a command-line tool that is freely available and easily automatable.

  1. Carcass traits and meat quality of different slow growing and fast growing broiler chickens

    Directory of Open Access Journals (Sweden)

    M. Oblakova

    2017-12-01

    dry matter higher percentage was associated with better lavor of meat. The analysis of the effect of genotype on meat protein content showed that protein content was the highest in the breast of slow-growing chickens from group III- 24.89% and lowest in the breast meat of conventional broilers from group V – 23.86% (p<0.05. In the other 3 groups, it ranged from 24.55 to 24.59%. The protein content of thighs was the lowest in slow-growing birds from group I- 19.49%, and the difference was the highest when compared to groups II and III, also slow-growing (p<0.05. With respect to the thigh fat content, it was the highest in slow-growing chickens from group IV (5.84%, followed by fast-growing from group V (5.33% and the lowest- in slow-growing birds from group І – 4.12% (p<0.05. The analysis of data showed a statistically significant effect of the sex on water content (p<0.001, fat (p<0.001 and ash (p<0.01. In males, thigh meat contained water and ash and in females more fat. The interaction of genotype and sex effects were important for thigh meat fat content, with highest values in fast-growing females from group V – 5.98% and lowest in slowly growing males from group I – 3.88% (p<0.001. Weak but statistically significant interaction between both factors was found with respect to thigh protein and ash (p<0.05. The highest protein content was established in slow-growing females from group IV (19.81%, whereas thigh ash was with highest percentage in slow-growing males from group II (1.11%

  2. Soil phosphorus heterogeneity promotes tree species diversity and phylogenetic clustering in a tropical seasonal rainforest.

    Science.gov (United States)

    Xu, Wumei; Ci, Xiuqin; Song, Caiyun; He, Tianhua; Zhang, Wenfu; Li, Qiaoming; Li, Jie

    2016-12-01

    The niche theory predicts that environmental heterogeneity and species diversity are positively correlated in tropical forests, whereas the neutral theory suggests that stochastic processes are more important in determining species diversity. This study sought to investigate the effects of soil nutrient (nitrogen and phosphorus) heterogeneity on tree species diversity in the Xishuangbanna tropical seasonal rainforest in southwestern China. Thirty-nine plots of 400 m 2 (20 × 20 m) were randomly located in the Xishuangbanna tropical seasonal rainforest. Within each plot, soil nutrient (nitrogen and phosphorus) availability and heterogeneity, tree species diversity, and community phylogenetic structure were measured. Soil phosphorus heterogeneity and tree species diversity in each plot were positively correlated, while phosphorus availability and tree species diversity were not. The trees in plots with low soil phosphorus heterogeneity were phylogenetically overdispersed, while the phylogenetic structure of trees within the plots became clustered as heterogeneity increased. Neither nitrogen availability nor its heterogeneity was correlated to tree species diversity or the phylogenetic structure of trees within the plots. The interspecific competition in the forest plots with low soil phosphorus heterogeneity could lead to an overdispersed community. However, as heterogeneity increase, more closely related species may be able to coexist together and lead to a clustered community. Our results indicate that soil phosphorus heterogeneity significantly affects tree diversity in the Xishuangbanna tropical seasonal rainforest, suggesting that deterministic processes are dominant in this tropical forest assembly.

  3. Growth and reproduction respond differently to climate in three Neotropical tree species.

    Science.gov (United States)

    Alfaro-Sánchez, Raquel; Muller-Landau, Helene C; Wright, S Joseph; Camarero, J Julio

    2017-06-01

    The response of tropical forests to anthropogenic climate change is critically important to future global carbon budgets, yet remains highly uncertain. Here, we investigate how precipitation, temperature, solar radiation and dry- and wet-season lengths are related to annual tree growth, flower production, and fruit production in three moist tropical forest tree species using long-term datasets from tree rings and litter traps in central Panama. We also evaluated how growth, flower, and fruit production were interrelated. We found that growth was positively correlated with wet-season precipitation in all three species: Jacaranda copaia (r = 0.63), Tetragastris panamensis (r = 0.39) and Trichilia tuberculata (r = 0.39). Flowering and fruiting in Jacaranda were negatively related to current-year dry-season rainfall and positively related to prior-year dry-season rainfall. Flowering in Tetragastris was negatively related to current-year annual mean temperature while Trichilia showed no significant relationships of reproduction with climate. Growth was significantly related to reproduction only in Tetragastris, where it was positively related to previous year fruiting. Our results suggest that tree growth in moist tropical forest tree species is generally reduced by drought events such as those associated with strong El Niño events. In contrast, interannual variation in reproduction is not generally associated with growth and has distinct and species-specific climate responses, with positive effects of El Niño events in some species. Understanding these contrasting climate effects on tree growth and reproduction is critical to predicting changes in tropical forest dynamics and species composition under climate change.

  4. Heavy metal accumulation in trees growing on contaminated sites in Central Europe

    International Nuclear Information System (INIS)

    Unterbrunner, R.; Puschenreiter, M.; Sommer, P.; Wieshammer, G.; Tlustos, P.; Zupan, M.; Wenzel, W.W.

    2007-01-01

    Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. We investigated Zn and Cd accumulation in tissues of adult trees and associated herbaceous species collected from contaminated areas in Central Europe. We found considerable Cd and Zn accumulation in various willow, poplar and birch species with up to 116 mg Cd kg -1 and 4680 mg Zn kg -1 in leaves of Salix caprea. Annual variation of Cd and Zn concentrations in leaves of Salix caprea were small, indicating that data obtained in different years can be compared. Metal concentrations in leaves were not related to total (aqua regia) or labile (1 M NH 4 NO 3 extract) concentrations in soil but the accumulation factors (leaf concentration: soil concentration) for Cd and Zn followed an inverse log type function. Metal partitioning between tissues showed a minimum in the wood, with increasing concentrations of Cd and Zn towards the leaves and fine roots. - Adult field-grown Salix caprea, Populus tremula and other tree species accumulate up to 4680 mg Zn kg -1 and 116 mg Cd kg -1 in their leaves

  5. Heavy metal accumulation in trees growing on contaminated sites in Central Europe

    Energy Technology Data Exchange (ETDEWEB)

    Unterbrunner, R. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Puschenreiter, M. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria)]. E-mail: markus.puschenreiter@boku.ac.at; Sommer, P. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Wieshammer, G. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Tlustos, P. [Czech University of Agriculture Prague, 165 21 Praha 6-Suchdol (Czech Republic); Zupan, M. [University of Ljubljana, Biotechnical Faculty, Agronomy department, Jamnikarjeva 101, 1000 Ljubljana (Slovenia); Wenzel, W.W. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria)

    2007-07-15

    Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. We investigated Zn and Cd accumulation in tissues of adult trees and associated herbaceous species collected from contaminated areas in Central Europe. We found considerable Cd and Zn accumulation in various willow, poplar and birch species with up to 116 mg Cd kg{sup -1} and 4680 mg Zn kg{sup -1} in leaves of Salix caprea. Annual variation of Cd and Zn concentrations in leaves of Salix caprea were small, indicating that data obtained in different years can be compared. Metal concentrations in leaves were not related to total (aqua regia) or labile (1 M NH{sub 4}NO{sub 3} extract) concentrations in soil but the accumulation factors (leaf concentration: soil concentration) for Cd and Zn followed an inverse log type function. Metal partitioning between tissues showed a minimum in the wood, with increasing concentrations of Cd and Zn towards the leaves and fine roots. - Adult field-grown Salix caprea, Populus tremula and other tree species accumulate up to 4680 mg Zn kg{sup -1} and 116 mg Cd kg{sup -1} in their leaves.

  6. Crown-Level Tree Species Classification Using Integrated Airborne Hyperspectral and LIDAR Remote Sensing Data

    Science.gov (United States)

    Wang, Z.; Wu, J.; Wang, Y.; Kong, X.; Bao, H.; Ni, Y.; Ma, L.; Jin, J.

    2018-05-01

    Mapping tree species is essential for sustainable planning as well as to improve our understanding of the role of different trees as different ecological service. However, crown-level tree species automatic classification is a challenging task due to the spectral similarity among diversified tree species, fine-scale spatial variation, shadow, and underlying objects within a crown. Advanced remote sensing data such as airborne Light Detection and Ranging (LiDAR) and hyperspectral imagery offer a great potential opportunity to derive crown spectral, structure and canopy physiological information at the individual crown scale, which can be useful for mapping tree species. In this paper, an innovative approach was developed for tree species classification at the crown level. The method utilized LiDAR data for individual tree crown delineation and morphological structure extraction, and Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery for pure crown-scale spectral extraction. Specifically, four steps were include: 1) A weighted mean filtering method was developed to improve the accuracy of the smoothed Canopy Height Model (CHM) derived from LiDAR data; 2) The marker-controlled watershed segmentation algorithm was, therefore, also employed to delineate the tree-level canopy from the CHM image in this study, and then individual tree height and tree crown were calculated according to the delineated crown; 3) Spectral features within 3 × 3 neighborhood regions centered on the treetops detected by the treetop detection algorithm were derived from the spectrally normalized CASI imagery; 4) The shape characteristics related to their crown diameters and heights were established, and different crown-level tree species were classified using the combination of spectral and shape characteristics. Analysis of results suggests that the developed classification strategy in this paper (OA = 85.12 %, Kc = 0.90) performed better than LiDAR-metrics method (OA = 79

  7. Ambrosia Beetle (Coleoptera: Scolytidae) Species, Flight, and Attack on Living Eastern Cottonwood Trees.

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, D R; D.C. Booth: M.S. Wallace

    2005-12-01

    ABSTRACT In spring 2002, ambrosia beetles (Coleoptera: Scolytidae) infested an intensively managed 22-ha tree plantation on the upper coastal plain of South Carolina. Nearly 3,500 scolytids representing 28 species were captured in ethanol-baited traps from 18 June 2002 to 18 April 2004. More than 88% of total captures were exotic species. Five species [Dryoxylon onoharaensum (Murayama), Euwallacea validus (Eichhoff), Pseudopityophthorus minutissimus (Zimmermann), Xyleborus atratus Eichhoff, and Xyleborus impressus Eichhoff]) were collected in South Carolina for the first time. Of four tree species in the plantation, eastern cottonwood, Populus deltoides Bartram, was the only one attacked, with nearly 40% of the trees sustaining ambrosia beetle damage. Clone ST66 sustained more damage than clone S7C15. ST66 trees receiving fertilization were attacked more frequently than trees receiving irrigation, irrigation_fertilization, or controls, although the number of S7C15 trees attacked did not differ among treatments. The study location is near major shipping ports; our results demonstrate the necessity for intensive monitoring programs to determine the arrival, spread, ecology, and impact of exotic scolytids.

  8. Assessing the Significance of Above- and Belowground Carbon Allocation of Fast- and Slow-Growing Families of Loblolly Pine - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Topa, M. A.; Weinstein, D. A.; Retzlaff, W. A.

    2001-03-01

    During this project we experimentally evaluated the below-ground biomass and carbon allocation and partitioning of four different fast- and slow-growing families of loblolly pine located in Scotland County, NC, in an effort to increase the long-term performance of the crop. The trees were subjected to optimal nutrition and control since planting in 1993. Destructive harvests in 1998 and 2000 were used for whole?plant biomass estimates and to identify possible family differences in carbon acquisition (photosynthesis) and water use efficiency. At regular intervals throughout each year we sampled tissues for carbohydrate analyses to assess differences in whole-tree carbon storage. Mini rhizotron observation tubes were installed to monitor root system production and turnover. Stable isotope analysis was used to examine possible functional differences in water and nutrient acquisition of root systems between the various families. A genetic dissection of root ontogenic and architectural traits, including biomass partitioning, was conducted using molecular markers to better understand the functional implications of these traits on resource acquisition and whole-plant carbon allocation.

  9. Sampling procedures for inventory of commercial volume tree species in Amazon Forest.

    Science.gov (United States)

    Netto, Sylvio P; Pelissari, Allan L; Cysneiros, Vinicius C; Bonazza, Marcelo; Sanquetta, Carlos R

    2017-01-01

    The spatial distribution of tropical tree species can affect the consistency of the estimators in commercial forest inventories, therefore, appropriate sampling procedures are required to survey species with different spatial patterns in the Amazon Forest. For this, the present study aims to evaluate the conventional sampling procedures and introduce the adaptive cluster sampling for volumetric inventories of Amazonian tree species, considering the hypotheses that the density, the spatial distribution and the zero-plots affect the consistency of the estimators, and that the adaptive cluster sampling allows to obtain more accurate volumetric estimation. We use data from a census carried out in Jamari National Forest, Brazil, where trees with diameters equal to or higher than 40 cm were measured in 1,355 plots. Species with different spatial patterns were selected and sampled with simple random sampling, systematic sampling, linear cluster sampling and adaptive cluster sampling, whereby the accuracy of the volumetric estimation and presence of zero-plots were evaluated. The sampling procedures applied to species were affected by the low density of trees and the large number of zero-plots, wherein the adaptive clusters allowed concentrating the sampling effort in plots with trees and, thus, agglutinating more representative samples to estimate the commercial volume.

  10. Forest tree species discrimination in western Himalaya using EO-1 Hyperion

    Science.gov (United States)

    George, Rajee; Padalia, Hitendra; Kushwaha, S. P. S.

    2014-05-01

    The information acquired in the narrow bands of hyperspectral remote sensing data has potential to capture plant species spectral variability, thereby improving forest tree species mapping. This study assessed the utility of spaceborne EO-1 Hyperion data in discrimination and classification of broadleaved evergreen and conifer forest tree species in western Himalaya. The pre-processing of 242 bands of Hyperion data resulted into 160 noise-free and vertical stripe corrected reflectance bands. Of these, 29 bands were selected through step-wise exclusion of bands (Wilk's Lambda). Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) algorithms were applied to the selected bands to assess their effectiveness in classification. SVM was also applied to broadband data (Landsat TM) to compare the variation in classification accuracy. All commonly occurring six gregarious tree species, viz., white oak, brown oak, chir pine, blue pine, cedar and fir in western Himalaya could be effectively discriminated. SVM produced a better species classification (overall accuracy 82.27%, kappa statistic 0.79) than SAM (overall accuracy 74.68%, kappa statistic 0.70). It was noticed that classification accuracy achieved with Hyperion bands was significantly higher than Landsat TM bands (overall accuracy 69.62%, kappa statistic 0.65). Study demonstrated the potential utility of narrow spectral bands of Hyperion data in discriminating tree species in a hilly terrain.

  11. Comparison of leaf-on and leaf-off ALS data for mapping riparian tree species

    Science.gov (United States)

    Laslier, Marianne; Ba, Antoine; Hubert-Moy, Laurence; Dufour, Simon

    2017-10-01

    Forest species composition is a fundamental indicator of forest study and management. However, describing forest species composition at large scales and of highly diverse populations remains an issue for which remote sensing can provide significant contribution, in particular, Airborne Laser Scanning (ALS) data. Riparian corridors are good examples of highly valuable ecosystems, with high species richness and large surface areas that can be time consuming and expensive to monitor with in situ measurements. Remote sensing could be useful to study them, but few studies have focused on monitoring riparian tree species using ALS data. This study aimed to determine which metrics derived from ALS data are best suited to identify and map riparian tree species. We acquired very high density leaf-on and leaf-off ALS data along the Sélune River (France). In addition, we inventoried eight main riparian deciduous tree species along the study site. After manual segmentation of the inventoried trees, we extracted 68 morphological and structural metrics from both leaf-on and leaf-off ALS point clouds. Some of these metrics were then selected using Sequential Forward Selection (SFS) algorithm. Support Vector Machine (SVM) classification results showed good accuracy with 7 metrics (0.77). Both leaf-on and leafoff metrics were kept as important metrics for distinguishing tree species. Results demonstrate the ability of 3D information derived from high density ALS data to identify riparian tree species using external and internal structural metrics. They also highlight the complementarity of leaf-on and leaf-off Lidar data for distinguishing riparian tree species.

  12. Architecture of 53 rain forest tree species differing in adult stature and shade tolerance

    NARCIS (Netherlands)

    Poorter, L.; Bongers, F.J.J.M.; Sterck, F.J.; Wöll, H.

    2003-01-01

    Tree architecture determines a tree's light capture, stability, and efficiency of crown growth. The hypothesis that light demand and adult stature of tree species within a community, independently of each other, determine species' architectural traits was tested by comparing 53 Liberian rain forest

  13. Tree species diversity and distribution patterns in tropical forests of Garo Hills.

    Science.gov (United States)

    A. Kumar; B.G. Marcot; A. Saxena

    2006-01-01

    We analyzed phytosociological characteristics and diversity patterns of tree species of tropical forests of Garo Hills, western Meghalaya, northeast India. The main vegetation of the region included primary forests, secondary forests, and sal (Shorea robusta) plantations, with 162, 132, and 87 tree species, respectively. The Shannon-Wiener...

  14. Optimal tree-stem bucking of northeastern species of China

    Science.gov (United States)

    Jingxin Wang; Chris B. LeDoux; Joseph McNeel

    2004-01-01

    An application of optimal tree-stem bucking to the northeastern tree species of China is reported. The bucking procedures used in this region are summarized, which are the basic guidelines for the optimal bucking design. The directed graph approach was adopted to generate the bucking patterns by using the network analysis labeling algorithm. A computer-based bucking...

  15. Genetic structure of two pseudoscorpion species living in tree hollows in Sweden

    Directory of Open Access Journals (Sweden)

    Ranius, T.

    2002-12-01

    Full Text Available Two saproxylic pseudoscorpions, Larca lata and Allochernes wideri, were compared in an analysis of genetic structure in southern Sweden. Allochernes wideri is a relatively widely distributed species that occurs in single-standing trees and in small tree hollows, while L. lata is on the Swedish red list and confined to larger assemblages of very old trees with hollows containing large amounts of wood mould. In A. wideri, the polymorphism of PGM was used, whereas in L. lata the variation for PGI was studied. The genetic differentiation between trees within a site was low for both species, indicating that the migration between nearby trees is considerable despite the fact that phoretic dispersal has only been occasionally observed in these species. Between sites, situated four to 900 km from each other, the genetic differentiation was small both in A. wideri and L. lata with no difference between the species, when considered on the mainland only. The small differentiation suggests the habitat was fragmented recently (100-170 years ago. The relation between the rate of migration and long-term population survival and the risk of mis-interpretation due to selection for alleles is discussed

  16. Tree diversity and species identity effects on soil fungi, protists and animals are context dependent.

    Science.gov (United States)

    Tedersoo, Leho; Bahram, Mohammad; Cajthaml, Tomáš; Põlme, Sergei; Hiiesalu, Indrek; Anslan, Sten; Harend, Helery; Buegger, Franz; Pritsch, Karin; Koricheva, Julia; Abarenkov, Kessy

    2016-02-01

    Plant species richness and the presence of certain influential species (sampling effect) drive the stability and functionality of ecosystems as well as primary production and biomass of consumers. However, little is known about these floristic effects on richness and community composition of soil biota in forest habitats owing to methodological constraints. We developed a DNA metabarcoding approach to identify the major eukaryote groups directly from soil with roughly species-level resolution. Using this method, we examined the effects of tree diversity and individual tree species on soil microbial biomass and taxonomic richness of soil biota in two experimental study systems in Finland and Estonia and accounted for edaphic variables and spatial autocorrelation. Our analyses revealed that the effects of tree diversity and individual species on soil biota are largely context dependent. Multiple regression and structural equation modelling suggested that biomass, soil pH, nutrients and tree species directly affect richness of different taxonomic groups. The community composition of most soil organisms was strongly correlated due to similar response to environmental predictors rather than causal relationships. On a local scale, soil resources and tree species have stronger effect on diversity of soil biota than tree species richness per se.

  17. Predicting spatial variations of tree species richness in tropical forests from high-resolution remote sensing.

    Science.gov (United States)

    Fricker, Geoffrey A; Wolf, Jeffrey A; Saatchi, Sassan S; Gillespie, Thomas W

    2015-10-01

    There is an increasing interest in identifying theories, empirical data sets, and remote-sensing metrics that can quantify tropical forest alpha diversity at a landscape scale. Quantifying patterns of tree species richness in the field is time consuming, especially in regions with over 100 tree species/ha. We examine species richness in a 50-ha plot in Barro Colorado Island in Panama and test if biophysical measurements of canopy reflectance from high-resolution satellite imagery and detailed vertical forest structure and topography from light detection and ranging (lidar) are associated with species richness across four tree size classes (>1, 1-10, >10, and >20 cm dbh) and three spatial scales (1, 0.25, and 0.04 ha). We use the 2010 tree inventory, including 204,757 individuals belonging to 301 species of freestanding woody plants or 166 ± 1.5 species/ha (mean ± SE), to compare with remote-sensing data. All remote-sensing metrics became less correlated with species richness as spatial resolution decreased from 1.0 ha to 0.04 ha and tree size increased from 1 cm to 20 cm dbh. When all stems with dbh > 1 cm in 1-ha plots were compared to remote-sensing metrics, standard deviation in canopy reflectance explained 13% of the variance in species richness. The standard deviations of canopy height and the topographic wetness index (TWI) derived from lidar were the best metrics to explain the spatial variance in species richness (15% and 24%, respectively). Using multiple regression models, we made predictions of species richness across Barro Colorado Island (BCI) at the 1-ha spatial scale for different tree size classes. We predicted variation in tree species richness among all plants (adjusted r² = 0.35) and trees with dbh > 10 cm (adjusted r² = 0.25). However, the best model results were for understory trees and shrubs (dbh 1-10 cm) (adjusted r² = 0.52) that comprise the majority of species richness in tropical forests. Our results indicate that high

  18. Leaf Protein and Mineral Concentrations across the "Miracle Tree" Genus Moringa.

    Science.gov (United States)

    Olson, Mark E; Sankaran, Renuka P; Fahey, Jed W; Grusak, Michael A; Odee, David; Nouman, Wasif

    2016-01-01

    The moringa tree Moringa oleifera is a fast-growing, drought-resistant tree cultivated across the lowland dry tropics worldwide for its nutritious leaves. Despite its nutritious reputation, there has been no systematic survey of the variation in leaf nutritional quality across M. oleifera grown worldwide, or of the other species of the genus. To guide informed use of moringa, we surveyed protein, macro-, and micro- nutrients across 67 common garden samples of 12 Moringa taxa, including 23 samples of M. oleifera. Moringa oleifera, M. concanensis, M. stenopetala, an M. concanensis X oleifera hybrid, and M. longituba were highest in protein, with M. ruspoliana having the highest calcium levels. A protein-dry leaf mass tradeoff may preclude certain breeding possibilities, e.g. maximally high protein with large leaflets. These findings identify clear priorities and limitations for improved moringa varieties with traits such as high protein, calcium, or ease of preparation.

  19. Is Tree Species Diversity or Species Identity the More Important Driver of Soil Carbon Stocks, C/N Ratio, and pH?

    DEFF Research Database (Denmark)

    Dawud, Seid Muhie; Raulund-Rasmussen, Karsten; Domisch, Timo

    2016-01-01

    We explored tree species diversity effects on soil C stock, C/N ratio, and pH as compared with effects of tree species identity. We sampled forest floors and mineral soil (0–40 cm) in a diversity gradient of 1–5 tree species composed of conifers and broadleaves in Białowieża Forest, Poland...... mechanism for higher root carbon input and in turn a deeper distribution of C in diverse forests. Diversity and identity affected soil pH in topsoil with positive and negative impacts, respectively. More diverse forests would lead to higher soil nutrient status as reflected by higher topsoil p......H, but there was a slight negative effect on N status as indicated by higher C/N ratios in the deeper layers. We conclude that tree species diversity increases soil C stocks and nutrient status to some extent, but tree species identity is a stronger driver of the studied soil properties, particularly in the topsoil....

  20. Assisted migration: What it means to nursery managers and tree planters

    Science.gov (United States)

    Mary I. Williams; R. Kasten Dumroese

    2014-01-01

    Projections indicate that natural plant adaptation and migration may not keep pace with climate changes. This mismatch in rates will pose significant challenges for practitioners that select, grow, and outplant native tree species. Populations of native tree species planted today must be able to meet the climatic challenges they will face during this century. One...

  1. Tree species traits influence soil physical, chemical, and biological properties in high elevation forests.

    Directory of Open Access Journals (Sweden)

    Edward Ayres

    Full Text Available BACKGROUND: Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. METHODOLOGY/PRINCIPAL FINDINGS: We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N concentration and lowest lignin:N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin:N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid

  2. Growing Greener Cities: A Tree-Planting Handbook.

    Science.gov (United States)

    Moll, Gary; Young, Stanley

    This step-by-step guide, developed by the Global ReLeaf organization, presents tree-planting advice and simple steps to organizing a successful community tree-planting and tree-care program. The text is divided into three parts. Part 1 introduces trees and discusses the role they play as components of the living urban environment. Distinctions are…

  3. How much does climate change threaten European forest tree species distributions?

    Science.gov (United States)

    Dyderski, Marcin K; Paź, Sonia; Frelich, Lee E; Jagodziński, Andrzej M

    2018-03-01

    Although numerous species distribution models have been developed, most were based on insufficient distribution data or used older climate change scenarios. We aimed to quantify changes in projected ranges and threat level by the years 2061-2080, for 12 European forest tree species under three climate change scenarios. We combined tree distribution data from the Global Biodiversity Information Facility, EUFORGEN, and forest inventories, and we developed species distribution models using MaxEnt and 19 bioclimatic variables. Models were developed for three climate change scenarios-optimistic (RCP2.6), moderate (RCP4.5), and pessimistic (RPC8.5)-using three General Circulation Models, for the period 2061-2080. Our study revealed different responses of tree species to projected climate change. The species may be divided into three groups: "winners"-mostly late-successional species: Abies alba, Fagus sylvatica, Fraxinus excelsior, Quercus robur, and Quercus petraea; "losers"-mostly pioneer species: Betula pendula, Larix decidua, Picea abies, and Pinus sylvestris; and alien species-Pseudotsuga menziesii, Quercus rubra, and Robinia pseudoacacia, which may be also considered as "winners." Assuming limited migration, most of the species studied would face a significant decrease in suitable habitat area. The threat level was highest for species that currently have the northernmost distribution centers. Ecological consequences of the projected range contractions would be serious for both forest management and nature conservation. © 2017 John Wiley & Sons Ltd.

  4. New flux based dose–response relationships for ozone for European forest tree species

    International Nuclear Information System (INIS)

    Büker, P.; Feng, Z.; Uddling, J.; Briolat, A.; Alonso, R.; Braun, S.; Elvira, S.; Gerosa, G.; Karlsson, P.E.; Le Thiec, D.

    2015-01-01

    To derive O 3 dose–response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O 3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O 3 flux concept and represents a step forward in predicting O 3 damage to forests in a spatially and temporally varying climate. - Highlights: • We present new ozone flux based dose–response relationships for European trees. • The model-based study accounted for the soil water effect on stomatal flux. • Different statistically derived ozone flux thresholds were applied. • Climate region specific parameterisation often outperformed simplified parameterisation. • Findings could help redefining critical levels for ozone effects on trees. - New stomatal flux based ozone dose–response relationships for tree species are derived for the regional risk assessment of ozone effects on European forest ecosystems.

  5. Light-dependent leaf trait variation in 43 tropical dry forest tree species

    NARCIS (Netherlands)

    Markesteijn, L.; Poorter, L.; Bongers, F.J.J.M.

    2007-01-01

    Our understanding of leaf acclimation in relation to irradiance of fully grown or juvenile trees is mainly based on research involving tropical wet forest species. We studied sun¿shade plasticity of 24 leaf traits of 43 tree species in a Bolivian dry deciduous forest. Sampling was confined to small

  6. A novel approach to internal crown characterization for coniferous tree species classification

    Science.gov (United States)

    Harikumar, A.; Bovolo, F.; Bruzzone, L.

    2016-10-01

    The knowledge about individual trees in forest is highly beneficial in forest management. High density small foot- print multi-return airborne Light Detection and Ranging (LiDAR) data can provide a very accurate information about the structural properties of individual trees in forests. Every tree species has a unique set of crown structural characteristics that can be used for tree species classification. In this paper, we use both the internal and external crown structural information of a conifer tree crown, derived from a high density small foot-print multi-return LiDAR data acquisition for species classification. Considering the fact that branches are the major building blocks of a conifer tree crown, we obtain the internal crown structural information using a branch level analysis. The structure of each conifer branch is represented using clusters in the LiDAR point cloud. We propose the joint use of the k-means clustering and geometric shape fitting, on the LiDAR data projected onto a novel 3-dimensional space, to identify branch clusters. After mapping the identified clusters back to the original space, six internal geometric features are estimated using a branch-level analysis. The external crown characteristics are modeled by using six least correlated features based on cone fitting and convex hull. Species classification is performed using a sparse Support Vector Machines (sparse SVM) classifier.

  7. Biological and environmental controls on tree transpiration in a suburban landscape

    Science.gov (United States)

    Peters, Emily B.; McFadden, Joseph P.; Montgomery, Rebecca A.

    2010-12-01

    Tree transpiration provides a variety of ecosystem services in urban areas, including amelioration of urban heat island effects and storm water management. Tree species vary in the magnitude and seasonality of transpiration owing to differences in physiology, response to climate, and biophysical characteristics, thereby complicating efforts to manage evapotranspiration at city scales. We report sap flux measurements during the 2007 and 2008 growing seasons for dominant tree species in a suburban neighborhood of Minneapolis-Saint Paul, Minnesota, USA. Evergreen needleleaf trees had significantly higher growing season means and annual transpiration per unit canopy area (1.90 kg H2O m-2 d-1 and 307 kg H2O m-2 yr-1, respectively) than deciduous broadleaf trees (1.11 kg H2O m-2 d-1 and 153 kg H2O m-2 yr-1, respectively) because of a smaller projected canopy area (31.1 and 73.6 m2, respectively), a higher leaf area index (8.8 and 5.5 m2 m-2, respectively), and a longer growth season (8 and 4 months, respectively). Measurements also showed patterns consistent with the species' differences in xylem anatomy (conifer, ring porous, and diffuse porous). As the growing season progressed, conifer and diffuse porous genera had increased stomatal regulation to high vapor pressure deficit, while ring porous genera maintained greater and more constant stomatal regulation. These results suggest that evaporative responses to climate change in urban ecosystems will depend in part on species composition. Overall, plant functional type differences in canopy structure and growing season length were most important in explaining species' differences in midsummer and annual transpiration, offering an approach to predicting the evapotranspiration component of urban water budgets.

  8. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    Directory of Open Access Journals (Sweden)

    Kyle Dexter

    2016-09-01

    Full Text Available Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin.

  9. Field data analysis of asphalt road paving damages caused by tree roots

    Science.gov (United States)

    Weissteiner, Clemens; Rauch, Hans Peter

    2015-04-01

    Tree root damages are a frequent problem along paved cycling paths and service roads of rivers and streams. Damages occur mostly on streets with thin asphalt layers and especially in the upper part of the pavement structure. The maintainers of these roads are faced with frequent and high annual repair costs in order to guarantee traffic safety and pleasant cycling conditions. The focus of this research project is to get an insight in the processes governing the growth of the tree roots in asphalt layers and to develop test methods to avoid rood penetration into the road structure. Tree vegetation has been analysed selectively along a 300 km long cycle and service path of the Danube River in the region of Austria. Tree characteristics, topographic as well as hydrologic conditions have been analysed at 119 spots with different asphalt damage intensities. On 5 spots additional investigations on the root growth characteristics where performed. First results underline a high potential damage of pioneer trees which are growing naturally along rivers. Mostly, local occurring fast growing tree species penetrated the road layer structure. In a few cases other tree species where as well responsible for road structure damages. The age respectively the size of the trees didn't seem to influence significantly the occurrence of asphalt damages. Road structure damages were found to appear unaffected by hydrologic or topographic conditions. However, results have to be interpreted with care as the investigations represent a temporally limited view of the problem situation. The investigations of the root growth characteristics proved that tree roots penetrate the road structure mostly between the gravel sublayer and the asphalt layer as the layers it selves don't allow a penetration because of their high compaction. Furthermore roots appear to be attracted by condensed water at the underside of the asphalt layer. Further steps of the research project imply testing of different

  10. CROWN-LEVEL TREE SPECIES CLASSIFICATION USING INTEGRATED AIRBORNE HYPERSPECTRAL AND LIDAR REMOTE SENSING DATA

    Directory of Open Access Journals (Sweden)

    Z. Wang

    2018-05-01

    Full Text Available Mapping tree species is essential for sustainable planning as well as to improve our understanding of the role of different trees as different ecological service. However, crown-level tree species automatic classification is a challenging task due to the spectral similarity among diversified tree species, fine-scale spatial variation, shadow, and underlying objects within a crown. Advanced remote sensing data such as airborne Light Detection and Ranging (LiDAR and hyperspectral imagery offer a great potential opportunity to derive crown spectral, structure and canopy physiological information at the individual crown scale, which can be useful for mapping tree species. In this paper, an innovative approach was developed for tree species classification at the crown level. The method utilized LiDAR data for individual tree crown delineation and morphological structure extraction, and Compact Airborne Spectrographic Imager (CASI hyperspectral imagery for pure crown-scale spectral extraction. Specifically, four steps were include: 1 A weighted mean filtering method was developed to improve the accuracy of the smoothed Canopy Height Model (CHM derived from LiDAR data; 2 The marker-controlled watershed segmentation algorithm was, therefore, also employed to delineate the tree-level canopy from the CHM image in this study, and then individual tree height and tree crown were calculated according to the delineated crown; 3 Spectral features within 3 × 3 neighborhood regions centered on the treetops detected by the treetop detection algorithm were derived from the spectrally normalized CASI imagery; 4 The shape characteristics related to their crown diameters and heights were established, and different crown-level tree species were classified using the combination of spectral and shape characteristics. Analysis of results suggests that the developed classification strategy in this paper (OA = 85.12 %, Kc = 0.90 performed better than Li

  11. [Mahalanobis distance based hyperspectral characteristic discrimination of leaves of different desert tree species].

    Science.gov (United States)

    Lin, Hai-jun; Zhang, Hui-fang; Gao, Ya-qi; Li, Xia; Yang, Fan; Zhou, Yan-fei

    2014-12-01

    The hyperspectral reflectance of Populus euphratica, Tamarix hispida, Haloxylon ammodendron and Calligonum mongolicum in the lower reaches of Tarim River and Turpan Desert Botanical Garden was measured by using the HR-768 field-portable spectroradiometer. The method of continuum removal, first derivative reflectance and second derivative reflectance were used to deal with the original spectral data of four tree species. The method of Mahalanobis Distance was used to select the bands with significant differences in the original spectral data and transform spectral data to identify the different tree species. The progressive discrimination analyses were used to test the selective bands used to identify different tree species. The results showed that The Mahalanobis Distance method was an effective method in feature band extraction. The bands for identifying different tree species were most near-infrared bands. The recognition accuracy of four methods was 85%, 93.8%, 92.4% and 95.5% respectively. Spectrum transform could improve the recognition accuracy. The recognition accuracy of different research objects and different spectrum transform methods were different. The research provided evidence for desert tree species classification, monitoring biodiversity and the analysis of area in desert by using large scale remote sensing method.

  12. Fast growing aspens in the development of a plant micropropagation system based on plant-produced ethylene action

    International Nuclear Information System (INIS)

    Žiauka, Jonas; Kuusienė, Sigutė; Šilininkas, Mindaugas

    2013-01-01

    Representatives of the genus Populus (poplars), such as Populus tremula L. (European aspen) and its fast-growing hybrids, are recognized as being among the most suitable tree species for short rotation coppicing in Northern Europe. Several technologies have been developed for fast propagation of selected aspen genotypes, including laboratory (in vitro) micropropagation, which is usually based on the action of exogenous plant hormones. Seeking to minimize the use of the latter, the present study was designed to test if the conditions suitable for increased accumulation of plant-produced gas, including the gaseous plant hormone ethylene, inside a culture vessel could contribute to commercially desirable changes in aspen development. Shoot cultures of several European and hybrid (Populus tremuloides Michx. × P. tremula) aspen genotypes were studied using two different types of culture vessels: tightly sealed Petri dishes (15 × 54 mm) designed to provide restricted gas exchange (RGE) conditions, and capped (but not sealed) test tubes (150 × 18 mm) providing control conditions. Under RGE conditions, not only the positive impact of the ethylene precursors 1-aminocyclopropane-1-carboxylic-acid (ACC) and ethephon on shoot proliferation was demonstrated but also a several-fold increase, compared to the control conditions, in the mean shoot number per explant was recorded even on the hormone-free nutrient medium. Moreover, the shoots developed under RGE conditions were distinguished by superior rooting ability in the subsequent culture. These results suggest that a plant micropropagation system based on the action of plant-produced ethylene rather than of exogenous hormones is possible. -- Highlights: ► Aspen in vitro cultures were grown in different vessels. ► Small-volume vessels were used for restriction of gas exchange. ► Aspen explants produced most shoots in small-volume vessels. ► Shoot proliferation was increased due to explant response to ethylene.

  13. Spatially explicit multi-threat assessment of food tree species in Burkina Faso: A fine-scale approach.

    Directory of Open Access Journals (Sweden)

    Hannes Gaisberger

    Full Text Available Over the last decades agroforestry parklands in Burkina Faso have come under increasing demographic as well as climatic pressures, which are threatening indigenous tree species that contribute substantially to income generation and nutrition in rural households. Analyzing the threats as well as the species vulnerability to them is fundamental for priority setting in conservation planning. Guided by literature and local experts we selected 16 important food tree species (Acacia macrostachya, Acacia senegal, Adansonia digitata, Annona senegalensis, Balanites aegyptiaca, Bombax costatum, Boscia senegalensis, Detarium microcarpum, Lannea microcarpa, Parkia biglobosa, Sclerocarya birrea, Strychnos spinosa, Tamarindus indica, Vitellaria paradoxa, Ximenia americana, Ziziphus mauritiana and six key threats to them (overexploitation, overgrazing, fire, cotton production, mining and climate change. We developed a species-specific and spatially explicit approach combining freely accessible datasets, species distribution models (SDMs, climate models and expert survey results to predict, at fine scale, where these threats are likely to have the greatest impact. We find that all species face serious threats throughout much of their distribution in Burkina Faso and that climate change is predicted to be the most prevalent threat in the long term, whereas overexploitation and cotton production are the most important short-term threats. Tree populations growing in areas designated as 'highly threatened' due to climate change should be used as seed sources for ex situ conservation and planting in areas where future climate is predicting suitable habitats. Assisted regeneration is suggested for populations in areas where suitable habitat under future climate conditions coincides with high threat levels due to short-term threats. In the case of Vitellaria paradoxa, we suggest collecting seed along the northern margins of its distribution and considering assisted

  14. In vitro propagation of tropical hardwood tree species — A review (2001-2011)

    Science.gov (United States)

    Paula M. Pijut; Rochelle R. Beasley; Shaneka S. Lawson; Kaitlin J. Palla; Micah E. Stevens; Ying. Wang

    2012-01-01

    Tropical hardwood tree species are important economically and ecologically, and play a significant role in the biodiversity of plant and animal species within an ecosystem. There are over 600 species of tropical timbers in the world, many of which are commercially valuable in the international trade of plywood, roundwood, sawnwood, and veneer. Many of these tree...

  15. Management and conservation of tree squirrels: the importance of endemism, species richness, and forest condition

    Science.gov (United States)

    John L. Koprowski

    2005-01-01

    Tree squirrels are excellent indicators of forest health yet the taxon is understudied. Most tree squirrels in the Holarctic Region are imperiled with some level of legal protection. The Madrean Archipelago is the epicenter for tree squirrel diversity in North America with 5 endemic species and 2 introduced species. Most species of the region are poorly studied in...

  16. Distribution of Cd, Ck, Pb and Zn in Soil and Vegetation Compartments in Stands of Five Boreal Tree Species in N.E. Sweden

    International Nuclear Information System (INIS)

    Alriksson, A.; Eriksson, H. M.

    2001-01-01

    Concentrations and total quantity of cadmium (Cd), cupper (Cu),lead (Pb) and zink (Zn) were determined in biomass and soil compartments in a replicated tree species experiment with 27-yr-old stands growing on former farmland in N.E. Sweden. Sequential extractions of soil samples were performed in order to estimate the exchangeable and an organically bound fraction of each element. The tree species included were Picea abies (L.)H. Karst., Pinus sylvestris L., Pinus contorta Dougl., Larix sibirica Ledeb., and Betula pendula Roth.Tree species influenced the rate of removal of Cu, Pb and Zn in case of stemwood harvesting, and of Cd, Cu and Zn in the case of whole-tree harvesting. B. pendula and P. abies had higher quantities and average concentrations of Zn in the biomass. For all species, >50% of the Zn in the stems was found in the bark. P. abies and L. sibirica had higher quantities of Cu in the biomass than the other species.P. abies and P. contorta had high quantities of Cd in the biomass in relation to the other species. Branches and stembark contained high concentrations of Cd and Pb in relation to foliage and stemwood. Dead branches had especially high concentrations of Pb. The high accumulation rate of Zn in the biomass of B. pendula was related to a low exchangeable amount of Zn in the A horizon. In the superficial centimeters of the A horizon, a depletion similar to that found for Zn was detected for Cu, whereas for Cd and Pb, no correlations were found between quantities of elements in the trees and element pools in the soil

  17. Statistical analysis of texture in trunk images for biometric identification of tree species.

    Science.gov (United States)

    Bressane, Adriano; Roveda, José A F; Martins, Antônio C G

    2015-04-01

    The identification of tree species is a key step for sustainable management plans of forest resources, as well as for several other applications that are based on such surveys. However, the present available techniques are dependent on the presence of tree structures, such as flowers, fruits, and leaves, limiting the identification process to certain periods of the year. Therefore, this article introduces a study on the application of statistical parameters for texture classification of tree trunk images. For that, 540 samples from five Brazilian native deciduous species were acquired and measures of entropy, uniformity, smoothness, asymmetry (third moment), mean, and standard deviation were obtained from the presented textures. Using a decision tree, a biometric species identification system was constructed and resulted to a 0.84 average precision rate for species classification with 0.83accuracy and 0.79 agreement. Thus, it can be considered that the use of texture presented in trunk images can represent an important advance in tree identification, since the limitations of the current techniques can be overcome.

  18. Calcium weathering in forested soils and the effedt of different tree species

    NARCIS (Netherlands)

    Dijkstra, F.A.; Breemen, van N.; Jongmans, A.G.; Davies, G.R.; Likens, G.E.

    2003-01-01

    Soil weathering can be an important mechanism to neutralize acidity in forest soils. Tree species may differ in their effect on or response to soil weathering. We used soil mineral data and the natural strontium isotope ratio Sr-87/Sr-86 as a tracer to identify the effect of tree species on the Ca

  19. The role of hybridization in facilitating tree invasion

    Science.gov (United States)

    Hybridization events can generate additional genetic diversity on which natural selection can act and at times enhance invasiveness of the species. Invasive tree species are a growing ecological concern worldwide, and some of these invasions involve hybridization events pre- or post-introduction. Th...

  20. tree and shrub species integration in the crop-livestock farming ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    cash for investment in the required activities, easy land certification and market opportunity for tree and shrub products. The tree and shrub .... for its consistency, logical flow, coding and length were amended. .... TABLE 2. List of shrub species identified in the watershed of highlands of central Ethiopia. Scientific name.

  1. MPBoot: fast phylogenetic maximum parsimony tree inference and bootstrap approximation.

    Science.gov (United States)

    Hoang, Diep Thi; Vinh, Le Sy; Flouri, Tomáš; Stamatakis, Alexandros; von Haeseler, Arndt; Minh, Bui Quang

    2018-02-02

    The nonparametric bootstrap is widely used to measure the branch support of phylogenetic trees. However, bootstrapping is computationally expensive and remains a bottleneck in phylogenetic analyses. Recently, an ultrafast bootstrap approximation (UFBoot) approach was proposed for maximum likelihood analyses. However, such an approach is still missing for maximum parsimony. To close this gap we present MPBoot, an adaptation and extension of UFBoot to compute branch supports under the maximum parsimony principle. MPBoot works for both uniform and non-uniform cost matrices. Our analyses on biological DNA and protein showed that under uniform cost matrices, MPBoot runs on average 4.7 (DNA) to 7 times (protein data) (range: 1.2-20.7) faster than the standard parsimony bootstrap implemented in PAUP*; but 1.6 (DNA) to 4.1 times (protein data) slower than the standard bootstrap with a fast search routine in TNT (fast-TNT). However, for non-uniform cost matrices MPBoot is 5 (DNA) to 13 times (protein data) (range:0.3-63.9) faster than fast-TNT. We note that MPBoot achieves better scores more frequently than PAUP* and fast-TNT. However, this effect is less pronounced if an intensive but slower search in TNT is invoked. Moreover, experiments on large-scale simulated data show that while both PAUP* and TNT bootstrap estimates are too conservative, MPBoot bootstrap estimates appear more unbiased. MPBoot provides an efficient alternative to the standard maximum parsimony bootstrap procedure. It shows favorable performance in terms of run time, the capability of finding a maximum parsimony tree, and high bootstrap accuracy on simulated as well as empirical data sets. MPBoot is easy-to-use, open-source and available at http://www.cibiv.at/software/mpboot .

  2. Tree Size Comparison of Some Important Street Trees Growing at ...

    African Journals Online (AJOL)

    PROF HORSFALL

    More research is needed on these trees for healthy environment of city. The present ..... use and CO2 emissions from power plants. Environ. Poll. .... Anna. Bot., 65:567-574. Kozlowski, T.T., 1971. Growth and Development of. Trees. Vol. 1.

  3. Herbs versus Trees: Influences on Teenagers' Knowledge of Plant Species

    Science.gov (United States)

    Lückmann, Katrin; Menzel, Susanne

    2014-01-01

    The study reports on species knowledge among German adolescents (n = 507) as: (1) self-assessed evaluation of one's species knowledge; and (2) factual knowledge about popular local herbs and trees. Besides assessing species knowledge, we were interested in whether selected demographic factors, environmental attitude (as measured through the New…

  4. No evidence for consistent long-term growth stimulation of 13 tropical tree species: results from tree-ring analysis.

    Science.gov (United States)

    Groenendijk, Peter; van der Sleen, Peter; Vlam, Mart; Bunyavejchewin, Sarayudh; Bongers, Frans; Zuidema, Pieter A

    2015-10-01

    The important role of tropical forests in the global carbon cycle makes it imperative to assess changes in their carbon dynamics for accurate projections of future climate-vegetation feedbacks. Forest monitoring studies conducted over the past decades have found evidence for both increasing and decreasing growth rates of tropical forest trees. The limited duration of these studies restrained analyses to decadal scales, and it is still unclear whether growth changes occurred over longer time scales, as would be expected if CO2 -fertilization stimulated tree growth. Furthermore, studies have so far dealt with changes in biomass gain at forest-stand level, but insights into species-specific growth changes - that ultimately determine community-level responses - are lacking. Here, we analyse species-specific growth changes on a centennial scale, using growth data from tree-ring analysis for 13 tree species (~1300 trees), from three sites distributed across the tropics. We used an established (regional curve standardization) and a new (size-class isolation) growth-trend detection method and explicitly assessed the influence of biases on the trend detection. In addition, we assessed whether aggregated trends were present within and across study sites. We found evidence for decreasing growth rates over time for 8-10 species, whereas increases were noted for two species and one showed no trend. Additionally, we found evidence for weak aggregated growth decreases at the site in Thailand and when analysing all sites simultaneously. The observed growth reductions suggest deteriorating growth conditions, perhaps due to warming. However, other causes cannot be excluded, such as recovery from large-scale disturbances or changing forest dynamics. Our findings contrast growth patterns that would be expected if elevated CO2 would stimulate tree growth. These results suggest that commonly assumed growth increases of tropical forests may not occur, which could lead to erroneous

  5. Tree production in desert regions using effluent and water harvesting

    Science.gov (United States)

    Martin M. Karpiscak; Gerald J. Gottfried

    2000-01-01

    Treated municipal effluent combined with water harvesting can be used for land restoration and enhancing the growth of important riparian tree species. Paired studies in Arizona are assessing the potential of growing trees using mixtures of effluent and potable water. Trees are grown in the field and in containers. Initial results from the field show high survival for...

  6. Species-Level Differences in Hyperspectral Metrics among Tropical Rainforest Trees as Determined by a Tree-Based Classifier

    Directory of Open Access Journals (Sweden)

    Dar A. Roberts

    2012-06-01

    Full Text Available This study explores a method to classify seven tropical rainforest tree species from full-range (400–2,500 nm hyperspectral data acquired at tissue (leaf and bark, pixel and crown scales using laboratory and airborne sensors. Metrics that respond to vegetation chemistry and structure were derived using narrowband indices, derivative- and absorption-based techniques, and spectral mixture analysis. We then used the Random Forests tree-based classifier to discriminate species with minimally-correlated, importance-ranked metrics. At all scales, best overall accuracies were achieved with metrics derived from all four techniques and that targeted chemical and structural properties across the visible to shortwave infrared spectrum (400–2500 nm. For tissue spectra, overall accuracies were 86.8% for leaves, 74.2% for bark, and 84.9% for leaves plus bark. Variation in tissue metrics was best explained by an axis of red absorption related to photosynthetic leaves and an axis distinguishing bark water and other chemical absorption features. Overall accuracies for individual tree crowns were 71.5% for pixel spectra, 70.6% crown-mean spectra, and 87.4% for a pixel-majority technique. At pixel and crown scales, tree structure and phenology at the time of image acquisition were important factors that determined species spectral separability.

  7. Metal(loid) allocation and nutrient retranslocation in Pinus halepensis trees growing on semiarid mine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Parraga-Aguado, Isabel, E-mail: isabel.parraga@upct.es [Universidad Politecnica de Cartagena, Departamento de Ciencia y Tecnología Agraria Paseo Alfonso XIII, Cartagena 48. 30203 (Spain); Querejeta, Jose-Ignacio [Water and Soil Conservation Department, Centro de Edafología y Biología Aplicada del Segura CEBAS-CSIC Campus Universitario de Espinardo, PO Box 164, Espinardo-Murcia ES-30100 (Spain); González-Alcaraz, María Nazaret; Conesa, Hector M. [Universidad Politecnica de Cartagena, Departamento de Ciencia y Tecnología Agraria Paseo Alfonso XIII, Cartagena 48. 30203 (Spain)

    2014-07-01

    The goal of this study was to evaluate internal metal(loid) cycling and the risk of metal(loid) accumulation in litter from Pinus halepensis trees growing at a mine tailing disposal site in semiarid Southeast Spain. Internal nutrient retranslocation was also evaluated in order to gain insight into the ability of pine trees to cope with the low-fertility soil conditions at the tailings. We measured metal(loid) concentrations in the foliage (young and old needles), woody stems and fresh leaf litter of pine trees growing on tailings. The nutrient status and stable isotope composition of pine foliage (δ{sup 13}C, δ{sup 15}N, δ{sup 18}O as indicators of photosynthesis and water use efficiency) were also analyzed. Tailing soil properties in vegetation patches and in adjacent bare soil patches were characterized as well. Significant amounts of metal(loid)s such us Cd, Cu, Pb and Sb were immobilized in the woody stems of Pinus halepensis trees growing on tailings. Leaf litterfall showed high concentrations of As, Cd, Sb, Pb and Zn, which thereby return to the soil. However, water extractable metal(loid) concentrations in tailing soils were similar between vegetation patches (mineral soil under the litter layer) and bare soil patches. The pines growing on mine tailings showed very low foliar P concentrations in all leaf age classes, which suggests severe P deficiency. Young (current year) needles showed lower accumulation of metal(loid)s, higher nutrient concentrations (P and K), and higher water use efficiency (as indicated by and δ{sup 13}C and δ{sup 18}O data) than older needles. Substantial nutrient resorption occurred before leaf litterfall, with 46% retranslocation efficiency for P and 89% for K. In conclusion, phytostabilization of semiarid mine tailings with Pinus halepensis is feasible but would require careful monitoring of the trace elements released from litterfall, in order to assess the long term risk of metal(loid) transfer to the food chain

  8. Metal(loid) allocation and nutrient retranslocation in Pinus halepensis trees growing on semiarid mine tailings

    International Nuclear Information System (INIS)

    Parraga-Aguado, Isabel; Querejeta, Jose-Ignacio; González-Alcaraz, María Nazaret; Conesa, Hector M.

    2014-01-01

    The goal of this study was to evaluate internal metal(loid) cycling and the risk of metal(loid) accumulation in litter from Pinus halepensis trees growing at a mine tailing disposal site in semiarid Southeast Spain. Internal nutrient retranslocation was also evaluated in order to gain insight into the ability of pine trees to cope with the low-fertility soil conditions at the tailings. We measured metal(loid) concentrations in the foliage (young and old needles), woody stems and fresh leaf litter of pine trees growing on tailings. The nutrient status and stable isotope composition of pine foliage (δ 13 C, δ 15 N, δ 18 O as indicators of photosynthesis and water use efficiency) were also analyzed. Tailing soil properties in vegetation patches and in adjacent bare soil patches were characterized as well. Significant amounts of metal(loid)s such us Cd, Cu, Pb and Sb were immobilized in the woody stems of Pinus halepensis trees growing on tailings. Leaf litterfall showed high concentrations of As, Cd, Sb, Pb and Zn, which thereby return to the soil. However, water extractable metal(loid) concentrations in tailing soils were similar between vegetation patches (mineral soil under the litter layer) and bare soil patches. The pines growing on mine tailings showed very low foliar P concentrations in all leaf age classes, which suggests severe P deficiency. Young (current year) needles showed lower accumulation of metal(loid)s, higher nutrient concentrations (P and K), and higher water use efficiency (as indicated by and δ 13 C and δ 18 O data) than older needles. Substantial nutrient resorption occurred before leaf litterfall, with 46% retranslocation efficiency for P and 89% for K. In conclusion, phytostabilization of semiarid mine tailings with Pinus halepensis is feasible but would require careful monitoring of the trace elements released from litterfall, in order to assess the long term risk of metal(loid) transfer to the food chain. - Highlights: • Significant

  9. ANATOMICAL CHARACTERISTICS AND CHEMICAL PROPERTIES OF THE BRANCH-WOOD OF Schizolobium amazonicum DUCKE SPECIES AND ITS POTENTIAL USES

    Directory of Open Access Journals (Sweden)

    Yusup Amin

    2013-10-01

    Full Text Available The scale of forest degradation and deforestation in Indonesia has inspired the use of lesser-known wood species, which are potentially abundant and so far has not much been utilized. Utilization of these woods should be imposed not only of the stem wood but also of the branch-wood portions. Schizolobiumamazonicum Ducke treeis one of those lesser-known species, and growing fast with an MAIof3.68 cm/year.In Indonesia this species is only found in the Purwodadi Botanical Garden. A research was conducted to study the basic characteristics (anatomical aspects and chemical properties of the branch-wood portion of this species. The branch-wood materials were obtained from the Purwodadi Botanical Garden situated in Pasuruan (East Java. The specimens used were the first branch of the trunk (stem of nine-year old S. amazonicum tree (= 29.46 cm. The branch-wood samples were then examined for the anatomical aspects (macroscopic and microscopic characteristics and chemical properties (chemical composition. Results revealed that the anatomical properties of S.amazonicum branch-wood exhibited close similarities to those of sengon wood; it was light in appearance and white in color. Its fiber averaged about 1500 μm, and based on the fiber dimension's derived values the branch- wood fiber of this species was categorized into first-class quality for pulp and paper manufacture. Further, the chemical composition of this branch-wood compared favorably with that of sengon and mangium wood. The composition of extractive content thatsoluble in alcohol-benzene; lignin; holocellulose; and α-cellulose of this branch-wood were 2.46; 28.71; 80.64; and 50.47%, respectively. The overall assessment implied that the branch-wood portion of S.amazonicum tree affords favorable potential to be developed as raw material for pulp and paper manufacture. Also, considering that both sengon and mangium woods were already used in the pulp and paper industries as well as the trees are

  10. Arbuscular mycorrhizal fungal diversity and natural enemies promote coexistence of tropical tree species

    Science.gov (United States)

    Benedicte Bachelot; María Uriarte; Krista L. McGuire; Jill Thompson; Jess Zimmerman

    2017-01-01

    Negative population feedbacks mediated by natural enemies can promote species coexistence at the community scale through disproportionate mortality of numerically dominant (common) tree species. Simultaneously, associations with arbuscular mycorrhizal fungi (AMF) can result in positive effects on tree populations. Coupling data on seedling foliar damage from herbivores...

  11. Hide and go seek with temperature signals of Northeastern US Tree Species

    Science.gov (United States)

    Alexander, M. R.; Pederson, N.; Bishop, D. A.; Pearl, J. K.; Anchukaitis, K. J.

    2017-12-01

    Improving reconstructions of past climate is vital in providing long-term context for regional climate change. There have been only two published reconstructions of past temperatures in the northeastern U.S. (NEUS) since the 1980s, one based on Picea rubens, and one out in 2017 based upon Chamaecyparis thyoides (Atlantic white cedar; AWC). Because increased species diversity generally improves dendrohydroclimatic reconstructions and both Picea rubens and AWC have limitations as paleoproxies due to land-use and air pollution, we conducted a series of tests to ask, "Does species diversity improve reconstructions of temperature history in the northeastern United States?" The first two tests were performed on AWC and then a network of AWC and Picea rubens. Subsequent tests added groups of species or genera from a network of 230 tree-ring chronologies beginning with those having the strongest relation between warming temperatures and increased growth. PC1 of the AWC test represented 40% of the variance and showed a significant positive relation with winter temperature (r = 0.38). As additional species were included, the "winter temperature PC" accounted for less of the overall variance, ranging from 26% of the variance in test 2 to 5% by test 5. AWC is swamped by the hydroclimatic signal that dominates our network. Populations of species such as Fagus grandifolia, Fraxinus nigra, Juniperus virginiana, Liriodendron tulipifera, Pinus rigida, and Pinus strobus from our network loaded strongest with AWC on the winter temperature PC. Including multiple species accounted for almost 20% more variance in the winter temperature record than AWC alone. Although drought is a dominating influence of tree growth in this region, our results suggest that winter temperatures are recorded within NEUS tree rings. Increasing the species diversity of tree proxies has the potential for improving reconstruction of paleotemperatures in regions lacking latitudinal or altitudinal tree lines

  12. The influence of recent climate change on tree height growth differs with species and spatial environment.

    Science.gov (United States)

    Messaoud, Yassine; Chen, Han Y H

    2011-02-16

    Tree growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of tree growth to increased temperature and atmospheric carbon dioxide (CO₂) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant trees at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the tree growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both species was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO₂ concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO₂ concentration, did not only differ with tree species, but

  13. Allometric biomass equations for 12 tree species in coniferous and broadleaved mixed forests, Northeastern China.

    Science.gov (United States)

    He, Huaijiang; Zhang, Chunyu; Zhao, Xiuhai; Fousseni, Folega; Wang, Jinsong; Dai, Haijun; Yang, Song; Zuo, Qiang

    2018-01-01

    Understanding forest carbon budget and dynamics for sustainable resource management and ecosystem functions requires quantification of above- and below-ground biomass at individual tree species and stand levels. In this study, a total of 122 trees (9-12 per species) were destructively sampled to determine above- and below-ground biomass of 12 tree species (Acer mandshuricum, Acer mono, Betula platyphylla, Carpinus cordata, Fraxinus mandshurica, Juglans mandshurica, Maackia amurensis, P. koraiensis, Populus ussuriensis, Quercus mongolica, Tilia amurensis and Ulmus japonica) in coniferous and broadleaved mixed forests of Northeastern China, an area of the largest natural forest in the country. Biomass allocation was examined and biomass models were developed using diameter as independent variable for individual tree species and all species combined. The results showed that the largest biomass allocation of all species combined was on stems (57.1%), followed by coarse root (21.3%), branch (18.7%), and foliage (2.9%). The log-transformed model was statistically significant for all biomass components, although predicting power was higher for species-specific models than for all species combined, general biomass models, and higher for stems, roots, above-ground biomass, and total tree biomass than for branch and foliage biomass. These findings supplement the previous studies on this forest type by additional sample trees, species and locations, and support biomass research on forest carbon budget and dynamics by management activities such as thinning and harvesting in the northeastern part of China.

  14. [Effects of tree species on polysaccharides content of epiphytic Dendrobium officinale].

    Science.gov (United States)

    Guo, Ying-Ying; Zhu, Yan; Si, Jin-Ping; Liu, Jing-Jing; Wu, Cheng-Yong; Li, Hui

    2014-11-01

    To reveals the effects of tree species on polysaccharides content of epiphytic Dendrobium officinale. The polysaccharides content of D. officinale attached to living tress in wild or stumps in bionic-facility was determined by phenol-sulfuric acid method. There were extremely significant differences of polysaccharides content of D. officinale attached to different tree species, but the differences had no relationship with the form and nutrition of barks. The polysaccharides content of D. officinale mainly affected by the light intensity of environment, so reasonable illumination favored the accumulation of polysaccharides. Various polysaccharides content of D. officinal from different attached trees is due to the difference of light regulation, but not the form and nutrition of barks.

  15. Leaf Protein and Mineral Concentrations across the "Miracle Tree" Genus Moringa.

    Directory of Open Access Journals (Sweden)

    Mark E Olson

    Full Text Available The moringa tree Moringa oleifera is a fast-growing, drought-resistant tree cultivated across the lowland dry tropics worldwide for its nutritious leaves. Despite its nutritious reputation, there has been no systematic survey of the variation in leaf nutritional quality across M. oleifera grown worldwide, or of the other species of the genus. To guide informed use of moringa, we surveyed protein, macro-, and micro- nutrients across 67 common garden samples of 12 Moringa taxa, including 23 samples of M. oleifera. Moringa oleifera, M. concanensis, M. stenopetala, an M. concanensis X oleifera hybrid, and M. longituba were highest in protein, with M. ruspoliana having the highest calcium levels. A protein-dry leaf mass tradeoff may preclude certain breeding possibilities, e.g. maximally high protein with large leaflets. These findings identify clear priorities and limitations for improved moringa varieties with traits such as high protein, calcium, or ease of preparation.

  16. The Risk of Growing Fast: Does fast growth have a negative impact on the survival rates of firms?

    NARCIS (Netherlands)

    Zhou, Haibo; van der Zwan, Peter; de Kok, Jan; Hartog, Chantal

    2012-01-01

    Fast-growing firms are considered as the central drivers of job creation in the economy. There is an abundance of literature on the separate subjects of firm growth and firm survival. However, the relationship between survival and growth is neglected. Using the Dutch Longitudinal Enterprise Database

  17. Recruiting Conventional Tree Architecture Models into State-of-the-Art LiDAR Mapping for Investigating Tree Growth Habits in Structure.

    Science.gov (United States)

    Lin, Yi; Jiang, Miao; Pellikka, Petri; Heiskanen, Janne

    2018-01-01

    Mensuration of tree growth habits is of considerable importance for understanding forest ecosystem processes and forest biophysical responses to climate changes. However, the complexity of tree crown morphology that is typically formed after many years of growth tends to render it a non-trivial task, even for the state-of-the-art 3D forest mapping technology-light detection and ranging (LiDAR). Fortunately, botanists have deduced the large structural diversity of tree forms into only a limited number of tree architecture models, which can present a-priori knowledge about tree structure, growth, and other attributes for different species. This study attempted to recruit Hallé architecture models (HAMs) into LiDAR mapping to investigate tree growth habits in structure. First, following the HAM-characterized tree structure organization rules, we run the kernel procedure of tree species classification based on the LiDAR-collected point clouds using a support vector machine classifier in the leave-one-out-for-cross-validation mode. Then, the HAM corresponding to each of the classified tree species was identified based on expert knowledge, assisted by the comparison of the LiDAR-derived feature parameters. Next, the tree growth habits in structure for each of the tree species were derived from the determined HAM. In the case of four tree species growing in the boreal environment, the tests indicated that the classification accuracy reached 85.0%, and their growth habits could be derived by qualitative and quantitative means. Overall, the strategy of recruiting conventional HAMs into LiDAR mapping for investigating tree growth habits in structure was validated, thereby paving a new way for efficiently reflecting tree growth habits and projecting forest structure dynamics.

  18. Trade-Offs between Drought Survival and Rooting Strategy of Two South American Mediterranean Tree Species: Implications for Dryland Forests Restoration

    Directory of Open Access Journals (Sweden)

    Juan F. Ovalle

    2015-10-01

    Full Text Available Differences in water-acquisition strategies of tree root systems can determine the capacity to survive under severe drought. We evaluate the effects of field water shortage on early survival, growth and root morphological variables of two South American Mediterranean tree species with different rooting strategies during two growing seasons. One year-old Quillaja saponaria (deep-rooted and Cryptocarya alba (shallow-rooted seedlings were established under two watering treatments (2 L·week−1·plant−1 and no water in a complete randomized design. Watering improved the final survival of both species, but the increase was only significantly higher for the shallow-rooted species. The survival rates of deep- and shallow-rooted species was 100% and 71% with watering treatment, and 96% and 10% for the unwatered treatment, respectively. Root morphological variables of deep-rooted species such as surface area, volume, and diameter were higher under unwatered treatment. On the other hand, shallow-rooted species had a higher total root dry mass, length, surface area with watering treatments. Our findings suggest that deep-rooted species are highly recommended for reforestation in dry conditions, even under low soil water availability. Water supplements during the summer season can attenuate the differences between deep- and shallow-rooted species in their ability to survive drought during the early stage.

  19. Insect outbreak shifts the direction of selection from fast to slow growth rates in the long-lived conifer Pinus ponderosa.

    Science.gov (United States)

    de la Mata, Raul; Hood, Sharon; Sala, Anna

    2017-07-11

    Long generation times limit species' rapid evolution to changing environments. Trees provide critical global ecosystem services, but are under increasing risk of mortality because of climate change-mediated disturbances, such as insect outbreaks. The extent to which disturbance changes the dynamics and strength of selection is unknown, but has important implications on the evolutionary potential of tree populations. Using a 40-y-old Pinus ponderosa genetic experiment, we provide rare evidence of context-dependent fluctuating selection on growth rates over time in a long-lived species. Fast growth was selected at juvenile stages, whereas slow growth was selected at mature stages under strong herbivory caused by a mountain pine beetle ( Dendroctonus ponderosae ) outbreak. Such opposing forces led to no net evolutionary response over time, thus providing a mechanism for the maintenance of genetic diversity on growth rates. Greater survival to mountain pine beetle attack in slow-growing families reflected, in part, a host-based life-history trade-off. Contrary to expectations, genetic effects on tree survival were greatest at the peak of the outbreak and pointed to complex defense responses. Our results suggest that selection forces in tree populations may be more relevant than previously thought, and have implications for tree population responses to future environments and for tree breeding programs.

  20. Growing the urban forest: tree performance in response to biotic and abiotic land management

    Science.gov (United States)

    Emily E. Oldfield; Alexander J. Felson; D. S. Novem Auyeung; Thomas W. Crowther; Nancy F. Sonti; Yoshiki Harada; Daniel S. Maynard; Noah W. Sokol; Mark S. Ashton; Robert J. Warren; Richard A. Hallett; Mark A. Bradford

    2015-01-01

    Forests are vital components of the urban landscape because they provide ecosystem services such as carbon sequestration, storm-water mitigation, and air-quality improvement. To enhance these services, cities are investing in programs to create urban forests. A major unknown, however, is whether planted trees will grow into the mature, closed-canopied forest on which...

  1. Tree cover and species composition effects on academic performance of primary school students.

    Science.gov (United States)

    Sivarajah, Sivajanani; Smith, Sandy M; Thomas, Sean C

    2018-01-01

    Human exposure to green space and vegetation is widely recognized to result in physical and mental health benefits; however, to date, the specific effects of tree cover, diversity, and species composition on student academic performance have not been investigated. We compiled standardized performance scores in Grades 3 and 6 for the collective student body in 387 schools across the Toronto District School Board (TDSB), and examined variation in relation to tree cover, tree diversity, and tree species composition based on comprehensive inventories of trees on school properties combined with aerial-photo-based assessments of tree cover. Analyses accounted for variation due to socioeconomic factors using the learning opportunity index (LOI), a regional composite index of external challenges to learning that incorporates income and other factors, such as students with English as a second language. As expected, LOI had the greatest influence on student academic performance; however, the proportion of tree cover, as distinct from other types of "green space" such as grass, was found to be a significant positive predictor of student performance, accounting for 13% of the variance explained in a statistical model predicting mean student performance assessments. The effects of tree cover and species composition were most pronounced in schools that showed the highest level of external challenges, suggesting the importance of urban forestry investments in these schools.

  2. Climate Responses in Growth and Wood Anatomy of Imoprtant Forest Tree Species in Denmark

    DEFF Research Database (Denmark)

    Huang, Weiwei

    and high temperatures on the development of Danish tree species are scarcely investigated. Through a dendroecological approach this dissertation assessed the growth responses related to increment, xylem anatomy and wood property of eight different important tree species, namely Picea abies (L.) Karst......., Picea sitchensis (Bong.) Carr., Abies alba Mill., Abies grandis (Dougl.) Lindl., Pseudotsuga mensiesii (Mirb.) Franco, Larix kaempferi (Lamb.) Carr., Quercus robur L. and Fagus sylvatica L., to long-term drought and high temperatures, aiming at identifying a species portfolio matching future climate...... intolerant species, mainly due to their low drought tolerance (both species) and susceptibility to high autumn temperature (only P. abies). Overall, this dissertation improves the understanding of how drought and high temperatures have impacted and will influence the growth of tree species in Danish forest...

  3. Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland.

    Science.gov (United States)

    Hamberg, Leena; Lehvävirta, Susanna; Kotze, D Johan; Heikkinen, Juha

    2015-03-15

    Recent studies have shown a considerable increase in the abundance of rowan (Sorbus aucuparia) saplings in urban forests in Finland, yet the reasons for this increase are not well understood. Here we investigated whether canopy cover or tree species composition, i.e., the basal areas of different tree species in Norway spruce dominated urban forests, affects the abundances of rowan seedlings, saplings and trees. Altogether 24 urban forest patches were investigated. We sampled the number of rowan and other saplings, and calculated the basal areas of trees. We showed that rowan abundance was affected by tree species composition. The basal area of rowan trees (≥ 5 cm in diameter at breast height, dbh) decreased with increasing basal area of Norway spruce, while the cover of rowan seedlings increased with an increase in Norway spruce basal area. However, a decrease in the abundance of birch (Betula pendula) and an increase in the broad-leaved tree group (Acer platanoides, Alnus glutinosa, Alnus incana, Amelanchier spicata, Prunus padus, Quercus robur, Rhamnus frangula and Salix caprea) coincided with a decreasing number of rowans. Furthermore, rowan saplings were scarce in the vicinity of mature rowan trees. Although it seems that tree species composition has an effect on rowan, the relationship between rowan saplings and mature trees is complex, and therefore we conclude that regulating tree species composition is not an easy way to keep rowan thickets under control in urban forests in Finland. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Rapid decay of tree-community composition in Amazonian forest fragments

    Science.gov (United States)

    Laurance, William F.; Nascimento, Henrique E. M.; Laurance, Susan G.; Andrade, Ana; Ribeiro, José E. L. S.; Giraldo, Juan Pablo; Lovejoy, Thomas E.; Condit, Richard; Chave, Jerome; Harms, Kyle E.; D'Angelo, Sammya

    2006-01-01

    Forest fragmentation is considered a greater threat to vertebrates than to tree communities because individual trees are typically long-lived and require only small areas for survival. Here we show that forest fragmentation provokes surprisingly rapid and profound alterations in Amazonian tree-community composition. Results were derived from a 22-year study of exceptionally diverse tree communities in 40 1-ha plots in fragmented and intact forests, which were sampled repeatedly before and after fragment isolation. Within these plots, trajectories of change in abundance were assessed for 267 genera and 1,162 tree species. Abrupt shifts in floristic composition were driven by sharply accelerated tree mortality and recruitment within ≈100 m of fragment margins, causing rapid species turnover and population declines or local extinctions of many large-seeded, slow-growing, and old-growth taxa; a striking increase in a smaller set of disturbance-adapted and abiotically dispersed species; and significant shifts in tree size distributions. Even among old-growth trees, species composition in fragments is being restructured substantially, with subcanopy species that rely on animal seed-dispersers and have obligate outbreeding being the most strongly disadvantaged. These diverse changes in tree communities are likely to have wide-ranging impacts on forest architecture, canopy-gap dynamics, plant–animal interactions, and forest carbon storage. PMID:17148598

  5. Bioecology of tulip trees at the Ajara Black Sea coast

    Directory of Open Access Journals (Sweden)

    Tamara Tskhoidze

    2013-04-01

    Full Text Available Tulip trees (Liriodendron tulipifera L. andLiriodendron chinense(Hemsl. Sarg. grow well along the Batumi coastline, develop, bloom, produce fruit, give natural revival. There they already have blooming and fruiting self-seeds. Chinese tulip poplar sometimes reaches here bigger sizes than in natural habitat. It resists winter temperatures very well. Both species can be jointly used along the Caucasian Black Sea coast as ornamental trees because there are the most favorable conditions for their vegetation. Due the great resistance American tulip trees can grow along the coastline as well as inland of Ajara.

  6. Regenerative Resilience of Tree Species in a Degraded Forest within Mt Kenya Ecosystem

    International Nuclear Information System (INIS)

    Omenda, T.O; Kariuki, J.G; Kamondo, B.M; Kiamba, J.K

    2007-01-01

    There is widespread human induced degradation of natural forest in Kenya. The major challenge to this situation is to devise cost effective rehabilitation approaches to reverse this trend. A study was conducted in Nyanza province of Kenya describing the structure and diversity of a disturbed natural forest and understanding the role so various propagules, namely seed, soil seed bank and coppices in post-disturbance recovery. The pre-disturbance forest type was a podo-Cassipourea-Teclea tropical montane forest. Four 350 m long line-plot transects were randomly located within the forest. Tree and stump data were obtained from 20*20 m plots located at 50 m intervals, while sapling, seeding and soil seed bank data were obtained from 5*5 m, 1*1 m and 0.2*0.2*0.5 subplots respectively, nested within the large plot. An 'Index of Species Resilence' that defines their continued was developed based on the tree species ability to coppice and their representation in seedling, sapling and tree stages. The forest condition was highly heterogeneous as determined through spatial distribution of basal area, height and diameter of breast height (dbh) of trees and cut stumps, the latter an indicator of disturbance. The Resilience Index indicated that, out of the 40 tree species found in the forest, only 30% had stable presence while 50% had an unstable presence characterized by in key succession stages-implying low auto-recovery potential. Results indicated that, coppicing had a more critical role in regeneration than previously thought, with 78% of all cut-tree species coppicing while only 27.5% of all the trees species regenerated from seed. The role of soil seed bank in auto-recovery was insignificant in this site. The apparent high coppicing potential presents a new opportunity for managing natural forests

  7. The Commercial Profitability of Growing Hybrid Eucalyptus Clones in The Coast Province, Kenya

    Directory of Open Access Journals (Sweden)

    Balozi Bekuta Kirongo

    2014-04-01

    Full Text Available Due to the current high demand for timber, fuelwood, and building poles and the realization that tree growing may pay dividends in the short and long term, many farmers are planting trees on their farms. Farmers are increasingly planting eucalyptus partly due to the fast growth rates of the hybrid clones as well as the opportunity to earn money within a short time. In this paper we report on the profitability of growing eucalyptus hybrid clones in the coastal region, Kenya. Tree growth and cost data was sourced from farmers in Malindi, Kilifi, and Msambweni. Market information was sourced from hardwares in North and South Coast while tree growth models were used to provide average tree sizes at various ages. Results showed that a farmer could make a net income of upto Kshs.500,000.00 (USD6,250 in 5 years. Farmers in the South Coast (Kwale and Msambweni spent more on transport than their counterparts in the North Coast (near Gede-KEFRI. This, added to the fact that trees in the South Coast (Msambweni grew less compared to those in North Coast meant that farmers in the south made less profits.

  8. Host tree phenology affects vascular epiphytes at the physiological, demographic and community level

    Science.gov (United States)

    Einzmann, Helena J. R.; Beyschlag, Joachim; Hofhansl, Florian; Wanek, Wolfgang; Zotz, Gerhard

    2015-01-01

    The processes that govern diverse tropical plant communities have rarely been studied in life forms other than trees. Structurally dependent vascular epiphytes, a major part of tropical biodiversity, grow in a three-dimensional matrix defined by their hosts, but trees differ in their architecture, bark structure/chemistry and leaf phenology. We hypothesized that the resulting seasonal differences in microclimatic conditions in evergreen vs. deciduous trees would affect epiphytes at different levels, from organ physiology to community structure. We studied the influence of tree leaf phenology on vascular epiphytes on the Island of Barro Colorado, Panama. Five tree species were selected, which were deciduous, semi-deciduous or evergreen. The crowns of drought-deciduous trees, characterized by sunnier and drier microclimates, hosted fewer individuals and less diverse epiphyte assemblages. Differences were also observed at a functional level, e.g. epiphyte assemblages in deciduous trees had larger proportions of Crassulacean acid metabolism species and individuals. At the population level a drier microclimate was associated with lower individual growth and survival in a xerophytic fern. Some species also showed, as expected, lower specific leaf area and higher δ13C values when growing in deciduous trees compared with evergreen trees. As hypothesized, host tree leaf phenology influences vascular epiphytes at different levels. Our results suggest a cascading effect of tree composition and associated differences in tree phenology on the diversity and functioning of epiphyte communities in tropical lowland forests. PMID:25392188

  9. New flux based dose-response relationships for ozone for European forest tree species.

    Science.gov (United States)

    Büker, P; Feng, Z; Uddling, J; Briolat, A; Alonso, R; Braun, S; Elvira, S; Gerosa, G; Karlsson, P E; Le Thiec, D; Marzuoli, R; Mills, G; Oksanen, E; Wieser, G; Wilkinson, M; Emberson, L D

    2015-11-01

    To derive O3 dose-response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  10. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Invasive plants are species that can grow and spread aggressively, mature quickly, and invade an ecosystem causing economic and environmental damage. Invasive plants usually invade disturbed areas, but can also colonize small areas quickly, and may spread and dominate large areas in a few short years. Invasive plant species displace native or desirable forest...

  11. Vegetative propagation of twelve fodder tree species indigenous to ...

    African Journals Online (AJOL)

    Vegetative propagation of twelve fodder tree species indigenous to the Sahel, West Africa. Catherine Ky-Dembele, Jules Bayala, Antoine Kalinganire, Fatoumata Tata Traoré, Bréhima Koné, Alain Olivier ...

  12. Modern tree species composition reflects ancient Maya "forest gardens" in northwest Belize.

    Science.gov (United States)

    Ross, Nanci J

    2011-01-01

    Ecology and ethnobotany were integrated to assess the impact of ancient Maya tree-dominated home gardens (i.e., "forest gardens"), which contained a diversity of tree species used for daily household needs, on the modern tree species composition of a Mesoamerican forest. Researchers have argued that the ubiquity of these ancient gardens throughout Mesoamerica led to the dominance of species useful to Maya in the contemporary forest, but this pattern may be localized depending on ancient land use. The tested hypothesis was that species composition would be significantly different between areas of dense ancient residential structures (high density) and areas of little or no ancient settlement (low density). Sixty-three 400-m2 plots (31 high density and 32 low density) were censused around the El Pilar Archaeological Reserve in northwestern Belize. Species composition was significantly different, with higher abundances of commonly utilized "forest garden" species still persisting in high-density forest areas despite centuries of abandonment. Subsequent edaphic analyses only explained 5% of the species composition differences. This research provides data on the long-term impacts of Maya forests gardens for use in development of future conservation models. For Mesoamerican conservation programs to work, we must understand the complex ecological and social interactions within an ecosystem that developed in intimate association with humans.

  13. Methodology to evaluate the insecticide potential of forest tree species

    International Nuclear Information System (INIS)

    Morales Soto, Leon; Garcia P, Carlos Mario

    2000-01-01

    The flora diversity of Colombia has an enormous potential in the rational use of its forest resources. Trees with biocidal effects to control pests and diseases need to be investigated. The objective of this research was to develop a methodology with low costs, easy application and quick results. The methodology employed was as follows: selection of tree species based on bibliography, ancestral reports and personal observations. The process was as follows: field collection of plants, preparation of plants extracts and test with Artemia salina Leach to detect biological activity of the extracts using LC50. Bioassays with those extract more promising (LC50 less than 1000 ppm) Determination of active compounds. The methodology was employed with 5 forest tree species: guarea guidonia (L) Sleumer and trichia hirta L. (Meliaceae), Machaerium Moritzianum Benth. (Fabaceae), Swinglea glutinosa Merrill (rutaceae) and Mammea americana L. (Clusiaceae). Using Artemia salina Leach as indicator of biocidal potential, two species were selected as the most promising, those were: Swinglea glutinosa Merril and Machaerium moritzianum Benth. In addition bioassays were made to evaluate fagoinhibition on Atta cephalotes (L.) (Hym: Formicidae) and control of Alconeura. This methodology is recommended for this kind of research

  14. The longevity of broadleaf deciduous trees in Northern Hemisphere temperate forests: insights from tree-ring series

    Directory of Open Access Journals (Sweden)

    Alfredo eDi Filippo

    2015-05-01

    Full Text Available Understanding the factors controlling the expression of longevity in trees is still an outstanding challenge for tree biologists and forest ecologists. We gathered tree-ring data and literature for broadleaf deciduous (BD temperate trees growing in closed-canopy old-growth forests in the Northern Hemisphere to explore the role of geographic patterns, climate variability, and growth rates on longevity. Our pan-continental analysis, covering 32 species from 12 genera, showed that 300-400 years can be considered a baseline threshold for maximum tree lifespan in many temperate deciduous forests. Maximum age varies greatly in relation to environmental features, even within the same species. Tree longevity is generally promoted by reduced growth rates across large genetic differences and environmental gradients. We argue that slower growth rates, and the associated smaller size, provide trees with an advantage against biotic and abiotic disturbance agents, supporting the idea that size, not age, is the main constraint to tree longevity. The oldest trees were living most of their life in subordinate canopy conditions and/or within primary forests in cool temperate environments and outside major storm tracks. Very old trees are thus characterized by slow growth and often live in forests with harsh site conditions and infrequent disturbance events that kill much of the trees. Temperature inversely controls the expression of longevity in mesophilous species (Fagus spp., but its role in Quercus spp. is more complex and warrants further research in disturbance ecology. Biological, ecological and historical drivers must be considered to understand the constraints imposed to longevity within different forest landscapes.

  15. Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2016-01-01

    Full Text Available Subtropical evergreen broad-leaved forest (EBLF is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ≥50% for 19 species. The median length of germination time (MLG ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (≥15 cm in height within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration.

  16. Reversing a tree regeneration crisis in an endangered ecoregion.

    Science.gov (United States)

    Fischer, Joern; Stott, Jenny; Zerger, Andre; Warren, Garth; Sherren, Kate; Forrester, Robert I

    2009-06-23

    Global food demand is growing rapidly. Livestock grazing can provide a valuable source of protein, but conventional grazing is often unsustainable. We studied an 800,000-ha section of a threatened ecoregion in southeastern Australia. Conventional management in the region involves continuous livestock grazing with few rest periods and regular fertilizer application. By using remotely sensed data on tree cover and extensive field data on livestock grazing regimes, soil chemistry, tree diameters, and tree regeneration, we show that the region is facing a tree regeneration crisis. Under conventional management, across the region, millions of hectares of land currently supporting tens of millions of trees will be treeless within decades from now. This would have severe negative ramifications for biodiversity and key ecosystem services, including water infiltration and shade provision for livestock. However, we identified an unexpected win-win solution for tree regeneration and commercial grazing. A relatively new practice in the region is fast-rotational grazing, characterized by prolonged rest periods in between short, intensive grazing events. The probability of regeneration under fast-rotational grazing was up to 4-fold higher than under conventional grazing, and it did not differ significantly from the probability of regeneration in ungrazed areas. In addition, trees were more likely to regenerate where soil nutrient levels were low. These findings suggest that the tree regeneration crisis can be reversed by applying low-input, fast-rotational grazing. New policy settings supporting these practices could signal a turning point for the region, from ecological decline to ecological recovery.

  17. Recruiting Conventional Tree Architecture Models into State-of-the-Art LiDAR Mapping for Investigating Tree Growth Habits in Structure

    Directory of Open Access Journals (Sweden)

    Yi Lin

    2018-02-01

    Full Text Available Mensuration of tree growth habits is of considerable importance for understanding forest ecosystem processes and forest biophysical responses to climate changes. However, the complexity of tree crown morphology that is typically formed after many years of growth tends to render it a non-trivial task, even for the state-of-the-art 3D forest mapping technology—light detection and ranging (LiDAR. Fortunately, botanists have deduced the large structural diversity of tree forms into only a limited number of tree architecture models, which can present a-priori knowledge about tree structure, growth, and other attributes for different species. This study attempted to recruit Hallé architecture models (HAMs into LiDAR mapping to investigate tree growth habits in structure. First, following the HAM-characterized tree structure organization rules, we run the kernel procedure of tree species classification based on the LiDAR-collected point clouds using a support vector machine classifier in the leave-one-out-for-cross-validation mode. Then, the HAM corresponding to each of the classified tree species was identified based on expert knowledge, assisted by the comparison of the LiDAR-derived feature parameters. Next, the tree growth habits in structure for each of the tree species were derived from the determined HAM. In the case of four tree species growing in the boreal environment, the tests indicated that the classification accuracy reached 85.0%, and their growth habits could be derived by qualitative and quantitative means. Overall, the strategy of recruiting conventional HAMs into LiDAR mapping for investigating tree growth habits in structure was validated, thereby paving a new way for efficiently reflecting tree growth habits and projecting forest structure dynamics.

  18. Diversification rates and species richness across the Tree of Life.

    Science.gov (United States)

    Scholl, Joshua P; Wiens, John J

    2016-09-14

    Species richness varies dramatically among clades across the Tree of Life, by over a million-fold in some cases (e.g. placozoans versus arthropods). Two major explanations for differences in richness among clades are the clade-age hypothesis (i.e. species-rich clades are older) and the diversification-rate hypothesis (i.e. species-rich clades diversify more rapidly, where diversification rate is the net balance of speciation and extinction over time). Here, we examine patterns of variation in diversification rates across the Tree of Life. We address how rates vary across higher taxa, whether rates within higher taxa are related to the subclades within them, and how diversification rates of clades are related to their species richness. We find substantial variation in diversification rates, with rates in plants nearly twice as high as in animals, and rates in some eukaryotes approximately 10-fold faster than prokaryotes. Rates for each kingdom-level clade are then significantly related to the subclades within them. Although caution is needed when interpreting relationships between diversification rates and richness, a positive relationship between the two is not inevitable. We find that variation in diversification rates seems to explain most variation in richness among clades across the Tree of Life, in contrast to the conclusions of previous studies. © 2016 The Author(s).

  19. Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

    Science.gov (United States)

    Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

    2008-03-01

    Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

  20. The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.

    Science.gov (United States)

    Thorley, Rachel M S; Taylor, Lyla L; Banwart, Steve A; Leake, Jonathan R; Beerling, David J

    2015-09-01

    On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  1. Performance of Asian longhorned beetle among tree species

    Science.gov (United States)

    Kelli Hoover; Scott Ludwig; James Sellmer; Deborah McCullough; Laura Lazarus

    2003-01-01

    Two procedures were evaluated for assessing susceptibility of a variety of tree species to Anoplophora glabripennis. In the first procedure, adult beetles were caged with a section of sugar maple, northern red oak, white oak, honeylocust, eastern cottonwood, sycamore or tulip poplar wood and allowed to oviposit.

  2. Climatic extremes improve predictions of spatial patterns of tree species

    Science.gov (United States)

    Zimmermann, N.E.; Yoccoz, N.G.; Edwards, T.C.; Meier, E.S.; Thuiller, W.; Guisan, Antoine; Schmatz, D.R.; Pearman, P.B.

    2009-01-01

    Understanding niche evolution, dynamics, and the response of species to climate change requires knowledge of the determinants of the environmental niche and species range limits. Mean values of climatic variables are often used in such analyses. In contrast, the increasing frequency of climate extremes suggests the importance of understanding their additional influence on range limits. Here, we assess how measures representing climate extremes (i.e., interannual variability in climate parameters) explain and predict spatial patterns of 11 tree species in Switzerland. We find clear, although comparably small, improvement (+20% in adjusted D2, +8% and +3% in cross-validated True Skill Statistic and area under the receiver operating characteristics curve values) in models that use measures of extremes in addition to means. The primary effect of including information on climate extremes is a correction of local overprediction and underprediction. Our results demonstrate that measures of climate extremes are important for understanding the climatic limits of tree species and assessing species niche characteristics. The inclusion of climate variability likely will improve models of species range limits under future conditions, where changes in mean climate and increased variability are expected.

  3. Water and nitrogen dynamics in rotational woodlots of five tree species in western Tanzania

    NARCIS (Netherlands)

    Nyadzi, G.I.; Janssen, B.H.; Otsyina, R.M.; Booltink, H.W.G.; Ong, C.K.; Oenema, O.

    2003-01-01

    The objective of this study was to compare the effects of woodlots of five tree species, continuous maize (Zea mays L.) and natural fallow on soil water and nitrogen dynamics in western Tanzania. The tree species evaluated were Acacia crassicarpa (A. Cunn. ex Benth.), Acacia julifera ( Berth.),

  4. Leaf anatomical traits of non-arboreal savanna species along a gradient of tree encroachment

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Souza Pinheiro

    2017-10-01

    Full Text Available ABSTRACT In the Brazilian savanna (Cerrado of Brazil, fire suppression has transformed typical savanna formations (TS into forested savanna (FS due to the phenomenon of encroachment. Under encroachment, non-arboreal plants begin to receive less light due to greater tree density and canopy closure. Here we aim to evaluate if leaf anatomical traits of non-arboreal species differ according to the degree of tree encroachment at the Assis Ecological Station - São Paulo, Brazil. To this end, we evaluated leaf tissue thickness and specific leaf area (SLA in representative non-arboreal species occurring along a gradient of tree encroachment. Leaves of TS species showed a trend towards xeromorphism, with traits reported to facilitate survival under high luminosity, such as thick leaves, thick epidermis and mesophyll, and low SLA. In contrast, FS species exhibited mesomorphic leaves, with thin mesophyll and high SLA, which are able to capture diffuse light in denser environments. Thus, non-arboreal understory species with mesomorphic leaf traits should be favored in environments with denser vegetation in contrast to typical savanna species. The results suggest that typical non-arboreal savanna species would not survive under tree encroachment due to the low competitiveness of their leaf anatomical strategies in shady environments.

  5. Investigation of Growth and Survival of Transplanted Plane and Pine Trees According to IBA Application, Tree Age, Transplanting Time and Method

    Directory of Open Access Journals (Sweden)

    N. Etemadi

    2015-03-01

    Full Text Available The major problems in transplanting the landscape trees are high level of mortality and low establishment rate of transplanted trees, especially in the first year. In order to achieve the best condition for successful transplanting of pine and plane trees in Isfahan landscape, the present study was carried out based on a completely randomized block design with four replicates and three treatments including transplanting method (balled and burlapped and bare root, tree age (immature and mature and IBA application (0 and 150 mg/L. Trees were transplanted during 2009 and 2010 in three times (dormant season, early and late growing season. Survival rate and Relative Growth Rate index based on tree height (RGRH and trunk diameter (RGRD were measured during the first and second years. Trees transplanted early in the growing season showed the most survival percentage during the two years, as compared to other transplanting dates. Survival of Balled and burlapped and immature transplanted trees was significantly greater than bare root or mature trees. The significant effect of age treatment was continued in the second year. IBA treatment had no effect on survival rate of the studied species. Balled and burlapped and immature transplanted pine trees also had higher RGRH and RGRD compared to bare root or mature trees. According to the results of this study, early growing season is the best time for transplanting pine and plane trees. Also, transplanting of immature trees using balled and burlapped method is recommended to increase the survival and establishment rate.

  6. Neighborhood diversity of large trees shows independent species patterns in a mixed dipterocarp forest in Sri Lanka.

    Science.gov (United States)

    Punchi-Manage, Ruwan; Wiegand, Thorsten; Wiegand, Kerstin; Getzin, Stephan; Huth, Andreas; Gunatilleke, C V Savitri; Gunatilleke, I A U Nimal

    2015-07-01

    Interactions among neighboring individuals influence plant performance and should create spatial patterns in local community structure. In order to assess the role of large trees in generating spatial patterns in local species richness, we used the individual species-area relationship (ISAR) to evaluate the species richness of trees of different size classes (and dead trees) in circular neighborhoods with varying radius around large trees of different focal species. To reveal signals of species interactions, we compared the ISAR function of the individuals of focal species with that of randomly selected nearby locations. We expected that large trees should strongly affect the community structure of smaller trees in their neighborhood, but that these effects should fade away with increasing size class. Unexpectedly, we found that only few focal species showed signals of species interactions with trees of the different size classes and that this was less likely for less abundant focal species. However, the few and relatively weak departures from independence were consistent with expectations of the effect of competition for space and the dispersal syndrome on spatial patterns. A noisy signal of competition for space found for large trees built up gradually with increasing life stage; it was not yet present for large saplings but detectable for intermediates. Additionally, focal species with animal-dispersed seeds showed higher species richness in their neighborhood than those with gravity- and gyration-dispersed seeds. Our analysis across the entire ontogeny from recruits to large trees supports the hypothesis that stochastic effects dilute deterministic species interactions in highly diverse communities. Stochastic dilution is a consequence of the stochastic geometry of biodiversity in species-rich communities where the identities of the nearest neighbors of a given plant are largely unpredictable. While the outcome of local species interactions is governed for each

  7. Slope variation and population structure of tree species from different ecological groups in South Brazil.

    Science.gov (United States)

    Bianchini, Edmilson; Garcia, Cristina C; Pimenta, José A; Torezan, José M D

    2010-09-01

    Size structure and spatial arrangement of 13 abundant tree species were determined in a riparian forest fragment in Paraná State, South Brazil (23°16'S and 51°01'W). The studied species were Aspidosperma polyneuron Müll. Arg., Astronium graveolens Jacq. and Gallesia integrifolia (Spreng) Harms (emergent species); Alseis floribunda Schott, Ruprechtia laxiflora Meisn. and Bougainvillea spectabilis Willd. (shade-intolerant canopy species); Machaerium paraguariense Hassl, Myroxylum peruiferum L. and Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl. (shade-tolerant canopy species); Sorocea bonplandii (Baill.) Bürger, Trichilia casaretti C. Dc, Trichilia catigua A. Juss. and Actinostemon concolor (Spreng.) Müll. Arg. (understory small trees species). Height and diameter structures and basal area of species were analyzed. Spatial patterns and slope correlation were analyzed by Moran's / spatial autocorrelation coefficient and partial Mantel test, respectively. The emergent and small understory species showed the highest and the lowest variations in height, diameter and basal area. Size distribution differed among emergent species and also among canopy shade-intolerant species. The spatial pattern ranged among species in all groups, except in understory small tree species. The slope was correlated with spatial pattern for A. polyneuron, A. graveolens, A. floribunda, R. laxiflora, M. peruiferum and T. casaretti. The results indicated that most species occurred in specific places, suggesting that niche differentiation can be an important factor in structuring the tree community.

  8. Light requirements of Australian tropical vs. cool-temperate rainforest tree species show different relationships with seedling growth and functional traits.

    Science.gov (United States)

    Lusk, Christopher H; Kelly, Jeff W G; Gleason, Sean M

    2013-03-01

    A trade-off between shade tolerance and growth in high light is thought to underlie the temporal dynamics of humid forests. On the other hand, it has been suggested that tree species sorting on temperature gradients involves a trade-off between growth rate and cold resistance. Little is known about how these two major trade-offs interact. Seedlings of Australian tropical and cool-temperate rainforest trees were grown in glasshouse environments to compare growth versus shade-tolerance trade-offs in these two assemblages. Biomass distribution, photosynthetic capacity and vessel diameters were measured in order to examine the functional correlates of species differences in light requirements and growth rate. Species light requirements were assessed by field estimation of the light compensation point for stem growth. Light-demanding and shade-tolerant tropical species differed markedly in relative growth rates (RGR), but this trend was less evident among temperate species. This pattern was paralleled by biomass distribution data: specific leaf area (SLA) and leaf area ratio (LAR) of tropical species were significantly positively correlated with compensation points, but not those of cool-temperate species. The relatively slow growth and small SLA and LAR of Tasmanian light-demanders were associated with narrow vessels and low potential sapwood conductivity. The conservative xylem traits, small LAR and modest RGR of Tasmanian light-demanders are consistent with selection for resistance to freeze-thaw embolism, at the expense of growth rate. Whereas competition for light favours rapid growth in light-demanding trees native to environments with warm, frost-free growing seasons, frost resistance may be an equally important determinant of the fitness of light-demanders in cool-temperate rainforest, as seedlings establishing in large openings are exposed to sub-zero temperatures that can occur throughout most of the year.

  9. Predicting climate change extirpation risk for central and southern Appalachian forest tree species

    Science.gov (United States)

    Kevin M. Potter; William W. Hargrove; Frank H. Koch

    2010-01-01

    Climate change will likely pose a severe threat to the viability of certain forest tree species, which will be forced either to adapt to new conditions or to shift to more favorable environments if they are to survive. Several forest tree species of the central and southern Appalachians may be at particular risk, since they occur in limited high-elevation ranges and/or...

  10. Riparian trees as common denominators across the river flow ...

    African Journals Online (AJOL)

    Riparian tree species, growing under different conditions of water availability, can ... leaf area and increasing wood density correlating with deeper groundwater levels. ... and Sanddrifskloof Rivers (South Africa) under reduced flow conditions.

  11. Constructing an optimal decision tree for FAST corner point detection

    KAUST Repository

    Alkhalid, Abdulaziz; Chikalov, Igor; Moshkov, Mikhail

    2011-01-01

    In this paper, we consider a problem that is originated in computer vision: determining an optimal testing strategy for the corner point detection problem that is a part of FAST algorithm [11,12]. The problem can be formulated as building a decision tree with the minimum average depth for a decision table with all discrete attributes. We experimentally compare performance of an exact algorithm based on dynamic programming and several greedy algorithms that differ in the attribute selection criterion. © 2011 Springer-Verlag.

  12. Soil hydrology of agroforestry systems: Competition for water or positive tree-crops interactions?

    Science.gov (United States)

    Gerjets, Rowena; Richter, Falk; Jansen, Martin; Carminati, Andrea

    2017-04-01

    In dry periods during the growing season crops may suffer from severe water stress. The question arises whether the alternation of crop and tree strips might enhance and sustain soil water resources available for crops during drought events. Trees reduce wind exposure, decreasing the potential evapotranspiration of crops and soils; additionally hydraulic lift from the deep roots of trees to the drier top soil might provide additional water for shallow-rooted crops. To understand the above and belowground water relations of agroforestry systems, we measured soil moisture and soil water potential in crop strips as a function of distance to the trees at varying depth as well as meteorological parameters. At the agroforestry site Reiffenhausen, Lower Saxony, Germany, two different tree species are planted, each in one separated tree strip: willow breed Tordis ((Salix viminalis x Salix Schwerinii) x Salix viminalis) and poplar clone Max 1 (Populus nigra x Populus maximowiczii). In between the tree strips a crop strip of 24 m width was established with annual crop rotation, managed the same way as the reference site. During a drought period in May 2016 with less than 2 mm rain in four weeks, an overall positive effect on hydrological conditions of the agroforestry system was observed. The results show that trees shaded the soil surface, lowering the air temperature and further increasing the soil moisture in the crop strips compared to the reference site, which was located far from the trees. At the reference site the crops took up water in the upper soil (sunlight. The two tree species behaved differently. The poplar strips showed more marked diurnal changes in soil water potential, with fast drying during daytime and rewetting during nighttime. We suppose that the rewetting during nighttime was caused by hydraulic lift, which supports passively the drier upper soil with water from the wetter, lower soil layers. This experimental study shows the importance of above- and

  13. Chemical investigation on wood tree species in a temperate forest, east-northern Romania

    Directory of Open Access Journals (Sweden)

    Teaca, C. A.

    2007-02-01

    Full Text Available A quantitative evaluation of wood chemical components for some tree species in a forest area from east-northern Romania is presented here, through a comparative study from 1964 to 2000. Investigation upon the wood tree-rings in a Quercus robur L. tree species, as a dominant species, as regards its chemical composition and structure of the natural polymer constituents - cellulose and lignin - was also performed through chemical methods to separate the main wood components, FT-IR spectroscopy, and thermogravimetry. Having in view the impact of climate and external factors (such as pollutant depositions, some possible correlations between wood chemical composition and its further use can be made. The FT-IR spectra give evidence of differences in the frequency domains of 3400-2900 cm-1 and 1730-1640 cm-1, due to some interactions between the chemical groups (OH, C=O. The crystallinity index of cellulose presents variations in the oak wood tree-rings. Thermogravimetry analyses show different behaviour of cellulose at thermal decomposition, as a function of radial growth and tree’s height. A preliminary chemical investigation of oak wood sawdust shows a relatively high content of mineral elements (ash, compared with a previous study performed in 1964, fact that may indicate an intense drying process of the oak tree, a general phenomenon present in European forests for this species.

  14. [Effects of waterlogging on the growth and energy-metabolic enzyme activities of different tree species].

    Science.gov (United States)

    Wang, Gui-Bin; Cao, Fu-Liang; Zhang, Xiao-Yan; Zhang, Wang-Xiang

    2010-03-01

    Aimed to understand the waterlogging tolerance and adaptation mechanisms of different tree species, a simulated field experiment was conducted to study the growth and energy-metabolic enzyme activities of one-year-old seedlings of Taxodium distichum, Carya illinoensis, and Sapium sebiferum. Three treatments were installed, i. e., CK, waterlogging, and flooding, with the treatment duration being 60 days. Under waterlogging and flooding, the relative growth of test tree species was in the order of T. distichum > C. illinoensis > S. sebiferum, indicating that T. distichum had the strongest tolerance against waterlogging and flooding, while S. sebiferum had the weakest one. Also under waterlogging and flooding, the root/crown ratio of the three tree species increased significantly, suggesting that more photosynthates were allocated in roots, and the lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) activities of the tree species also had a significant increase. Among the test tree species, T. distichum had the lowest increment of LDH and ADH activities under waterlogging and flooding, but the increment could maintain at a higher level in the treatment duration, while for C. illinoensis and S. sebiferum, the increment was larger during the initial and medium period, but declined rapidly during the later period of treatment. The malate dehydrogenase (MDH), phosphohexose (HPI), and glucose-6-phosphate dehydrogenase (G6PDH) -6-phosphogluconate dehydrogenase (6PGDH) activities of the tree species under waterlogging and flooding had a significant decrease, and the decrement was the largest for T. distichum, being 35.6% for MDH, 21.0% for HPI, and 22.7% for G6PDH - 6PGDH under flooding. It was suggested that under waterlogging and flooding, the tree species with strong waterlogging tolerance had a higher ability to maintain energy-metabolic balance, and thus, its growth could be maintained at a certain level.

  15. Ecophysiological evaluation of tree species for biomonitoring of air quality and identification of air pollution-tolerant species.

    Science.gov (United States)

    Sen, Abhishek; Khan, Indrani; Kundu, Debajyoti; Das, Kousik; Datta, Jayanta Kumar

    2017-06-01

    Identification of tree species that can biologically monitor air pollution and can endure air pollution is very much important for a sustainable green belt development around any polluted place. To ascertain the species, ten tree species were selected on the basis of some previous study from the campus of the University of Burdwan and were studied in the pre-monsoon and post-monsoon seasons. The study has been designed to investigate biochemical and physiological activities of selected tree species as the campus is presently exposed to primary air pollutants and their impacts on plant community were observed through the changes in several physical and biochemical constituents of plant leaves. As the plant species continuously exchange different gaseous pollutants in and out of the foliar system and are very sensitive to gaseous pollutants, they serve as bioindicators. Due to air pollution, foliar surface undergoes different structural and functional changes. In the selected plant species, it was observed that the concentration of primary air pollutants, proline content, pH, relative water holding capacity, photosynthetic rate, and respiration rate were higher in the pre-monsoon than the post-monsoon season, whereas the total chlorophyll, ascorbic acid, sugar, and conductivity were higher in the post-monsoon season. From the entire study, it was observed that the concentration of sulfur oxide (SO x ), nitrogen oxide (NO x ), and suspended particulate matter (SPM) all are reduced in the post-monsoon season than the pre-monsoon season. In the pre-monsoon season, SO x , NO x , and SPM do not have any significant correlation with biochemical as well as physiological parameters. SPM shows a negative relationship with chlorophyll 'a' (r = -0.288), chlorophyll 'b' (r = -0.267), and total chlorophyll (r = -0.238). Similarly, chlorophyll a, chlorophyll b, and the total chlorophyll show negative relations with SO x and NO x (p tree species according to their air

  16. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2013-01-01

    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  17. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  18. [Research on identification of species of fruit trees by spectral analysis].

    Science.gov (United States)

    Xing, Dong-Xing; Chang, Qing-Rui

    2009-07-01

    Using the spectral reflectance data (R2) of canopies, the present paper identifies seven species of fruit trees bearing fruit in the fruit mature period. Firstly, it compares the fruit tree species identification capability of six kinds of satellite sensors and four kinds of vegetation index through re-sampling the spectral data with six kinds of pre-defined filter function and the related data processing of calculating vegetation indexes. Then, it structures a BP neural network model for identifying seven species of fruit trees on the basis of choosing the best transformation of R(lambda) and optimizing the model parameters. The main conclusions are: (1) the order of the identification capability of the six kinds of satellite sensors from strong to weak is: MODIS, ASTER, ETM+, HRG, QUICKBIRD and IKONOS; (2) among the four kinds of vegetation indexes, the identification capability of RVI is the most powerful, the next is NDVI, while the identification capability of SAVI or DVI is relatively weak; (3) The identification capability of RVI and NDVI calculated with the reflectance of near-infrared and red channels of ETM+ or MODIS sensor is relatively powerful; (4) Among R(lambda) and its 22 kinds of transformation data, d1 [log(1/R(lambda))](derivative gap is set 9 nm) is the best transformation for structuring BP neural network model; (5) The paper structures a 3-layer BP neural network model for identifying seven species of fruit trees using the best transformation of R(lambda) which is d1 [log(1/R(lambda))](derivative gap is set 9 nm).

  19. Fruit availability, frugivore satiation and seed removal in 2 primate-dispersed tree species.

    Science.gov (United States)

    Ratiarison, Sandra; Forget, Pierre-Michel

    2011-09-01

    During a mast-fruiting event we investigated spatial variability in fruit availability, consumption, and seed removal at two sympatric tree species, Manilkara bidentata and M. huberi (Sapotaceae) at Nouragues Natural Reserve, French Guiana. We addressed the question of how Manilkara density and fruits at the community level might be major causes of variability in feeding assemblages between tree species. We thus explored how the frugivore assemblages differed between forest patches with contrasting relative Manilkara density and fruiting context. During the daytime, Alouatta seniculus was more often observed in M. huberi crowns at Petit Plateau (PP) with the greatest density of Manilkara spp. and the lowest fruit diversity and availability, whereas Cebus apella and Saguinus midas were more often observed in M. bidentata crowns at both Grand Plateau (GP), with a lowest density of M. bidentata and overall greater fruit supply, and PP. Overall, nearly 53% and 15% of the M. bidentata seed crop at GP and PP, respectively, and about 47% of the M. huberi seed crop were removed, otherwise either spit out or defecated beneath trees, or dropped in fruits. Small-bodied primates concentrated fallen seeds beneath parent trees while large-bodied primate species removed and dispersed more seeds away from parents. However, among the latter, satiated A. seniculus wasted seeds under conspecific trees at PP. Variations in feeding assemblages, seed removal rates and fates possibly reflected interactions with extra-generic fruit species at the community level, according to feeding choice, habitat preferences and ranging patterns of primate species. © 2011 ISZS, Blackwell Publishing and IOZ/CAS.

  20. Responses of Calathea species in different growing media ...

    African Journals Online (AJOL)

    ... substrate of top soil and poultry manure mixtures. Although C.nigerica produced higher number of leaves and taller plants than C. zebrina, the latter may be preferred because of its more attractive leaves and its many plantlets that quickly fill the growing container. Key words: growth , container, media, Calathea Species.

  1. Intraspecific Variation in Armillaria Species from Shrubs and Trees in Northwestern Spain

    Directory of Open Access Journals (Sweden)

    O. Aguín

    2004-08-01

    Full Text Available Until recently, the identification of Armillaria species relied upon morphological characteristics and mating tests, but now molecular techniques based on polymorphisms in the IGS region of the fungal rDNA are more commonly used, since these are more rapid and reliable. Differences found in RFLP patterns identifying Armillaria species have suggested the existence of intraspecific variation. In this work, 185 Armillaria isolates from different plant species (including fruit trees, broadleaf and coniferous trees, ornamental shrubs, kiwifruit and grapevine affected by white root rot were analyzed by RFLP-PCR, in order to study intraspecific variation in Armillaria and the relationship with the plant host. Armillaria mellea was found in the majority of samples (71%, and was the most frequent Armillaria species in symptomatic ornamental shrubs, kiwifruit, grapevine, fruit trees and broadleaf trees. In conifers however white root rot was generally caused by Armillaria ostoyae. Armillaria gallica was identified, although with low incidence, in ornamental, coniferous, broadleaf and fruit hosts. Intraspecies variation was recorded only in A. mellea, for which RFLP patterns mel 1 and mel 2 were found. Most plants infected with A. mellea showed the mel 2 pattern. Further research is needed to study whether Armillaria RFLP patterns are specific to certain plant hosts, and whether intraspecific variation is related to differences in pathogenicity.

  2. The trait contribution to wood decomposition rates of 15 Neotropical tree species.

    Science.gov (United States)

    van Geffen, Koert G; Poorter, Lourens; Sass-Klaassen, Ute; van Logtestijn, Richard S P; Cornelissen, Johannes H C

    2010-12-01

    The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in species traits on differences in wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 tree species in a Bolivian semi-evergreen tropical moist forest. We hypothesized that interspecific differences in species traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr(-1). We measured 10 different chemical, anatomical, and morphological traits for all species. The species' average traits were useful predictors of wood decomposition rates, particularly the average diameter (dbh) of the tree species (R2 = 0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2 = 0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When dbh values of the actual dead trees sampled for decomposition rate determination were used as a predictor variable, the final model (including dead tree dbh and lignin concentration) explained even more variation in wood decomposition rates (R2 = 0.71), underlining the importance of dbh in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations, and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-species study, in which for the first time a large set of traits is explicitly linked to wood decomposition rates, merits further testing in other forest ecosystems.

  3. Utilization of lightflecks by seedlings of five dominant tree species of different subtropical forest successional stages under low-light growth conditions.

    Science.gov (United States)

    Zhang, Q; Chen, Y J; Song, L Y; Liu, N; Sun, L L; Peng, C L

    2012-05-01

    We selected five typical tree species, including one early-successional species (ES) Pinus massoniana Lamb., two mid-successional species (MS) Schima superba Gardn. et Champ. and Castanopsis fissa (Champ. ex Benth.) Rehd. et Wils. and two late-successional species (LS) Cryptocarya concinna Hance. and Acmena acuminatissima (BI.) Merr et Perry., which represent the plants at three successional periods in Dinghushan subtropical forest succession of southern China. Potted seedlings of the five species were grown under 12% of full sunlight for 36 months. The ES and MS showed the slowest and fastest responses to lightflecks, respectively, which correlated with the rate of stomatal opening. In contrast to P. massoniana and C. concinna, the other three species exhibited a high induction loss. Early-successional species showed the lowest specific leaf area and chlorophyll content, the highest photosynthetic capacity (A(max)) and respiratory carbon losses (R(d)). Compared with ES and MS, LS showed lower A(max) and R(d). The five tree species showed a similar chlorophyll a/b ratio after long-term low-light adaptations. On the other hand, LS had a relatively higher de-epoxidation state to protect themselves from excess light during lightflecks. Our results indicated that (i) slower responses to lightflecks could partially explain why ES species could not achieve seedling regeneration in low-light conditions; (ii) fast responses to lightflecks could partially explain why MS species could achieve seedling regeneration in low-light conditions; and (iii) smaller respiratory carbon losses might confer on the LS species a competitive advantage in low-light conditions.

  4. A support vector machine based test for incongruence between sets of trees in tree space

    Science.gov (United States)

    2012-01-01

    Background The increased use of multi-locus data sets for phylogenetic reconstruction has increased the need to determine whether a set of gene trees significantly deviate from the phylogenetic patterns of other genes. Such unusual gene trees may have been influenced by other evolutionary processes such as selection, gene duplication, or horizontal gene transfer. Results Motivated by this problem we propose a nonparametric goodness-of-fit test for two empirical distributions of gene trees, and we developed the software GeneOut to estimate a p-value for the test. Our approach maps trees into a multi-dimensional vector space and then applies support vector machines (SVMs) to measure the separation between two sets of pre-defined trees. We use a permutation test to assess the significance of the SVM separation. To demonstrate the performance of GeneOut, we applied it to the comparison of gene trees simulated within different species trees across a range of species tree depths. Applied directly to sets of simulated gene trees with large sample sizes, GeneOut was able to detect very small differences between two set of gene trees generated under different species trees. Our statistical test can also include tree reconstruction into its test framework through a variety of phylogenetic optimality criteria. When applied to DNA sequence data simulated from different sets of gene trees, results in the form of receiver operating characteristic (ROC) curves indicated that GeneOut performed well in the detection of differences between sets of trees with different distributions in a multi-dimensional space. Furthermore, it controlled false positive and false negative rates very well, indicating a high degree of accuracy. Conclusions The non-parametric nature of our statistical test provides fast and efficient analyses, and makes it an applicable test for any scenario where evolutionary or other factors can lead to trees with different multi-dimensional distributions. The

  5. Estimating the global conservation status of more than 15,000 Amazonian tree species

    Science.gov (United States)

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salomão, Rafael P.; Castilho, Carolina V.; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E.; Phillips, Oliver L.; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R.; Honorio Coronado, Euridice N.; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L.; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G. W.; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S.; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F.; Mogollón, Hugo F.; Piedade, Maria Teresa Fernandez; Aymard C., Gerardo A.; Comiskey, James A.; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W.; Jimenez, Eliana M.; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R.; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R.; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R.; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R.; Silva, Natalino; Vela, César I. A.; Vos, Vincent A.; Zent, Eglée L.; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A.; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R.; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N.; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H.; Gamarra, Luis Valenzuela

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442

  6. Thermotolerance and Photosystem II Behaviour in Co-occuring Temperate Tree Species Exposed to Short-term Extreme Heat Waves

    Science.gov (United States)

    Guha, A.; Warren, J.; Cummings, C.; Han, J.

    2017-12-01

    Thermal stress can induce irreversible photodamage with longer consequences for plant metabolism. We focused on photosystem II (PSII) behaviour to understand how this complex responds in different co-occuring temperate trees exposed to short-term extreme heat waves. The study was designed for understanding complex heat tolerance mechanisms in trees. During manipulative heat-wave experiments, we monitored instantaneous PSII performance and tracked both transient and chronic PSII damages using chlorophyll a fluorescence characteristics. Fluorescence signals were used to simulate PSII bioenergetic processes. The light (Fv'/Fm') and dark-adapted (Fv/Fm) fluorescence traits including fast induction kinetics (OJIP), electron transport rate, PSII operating efficiency and quenching capacities were significantly affected by the heat treatments. Loss in PSII efficiency was more apparent in species like black cottonwood, yellow poplar, walnuts and conifers, whereas oaks maintained relatively better PSII functions. The post-heat recovery of Fv/Fm varied across the studied species showing differential carry over effects. PSII down-regulation was one of dominant factors for the loss in operational photosynthesis during extreme heat wave events. Both light and dark-adapted fluorescence characteristics showed loss in photo-regulatory functions and photodamage. Some resilient species showed rapid recovery from transient PSII damage, whereas fingerprints of chronic PSII damage were observed in susceptibles. Thresholds for Fv/Fm and non-photochemical quenching were identified for the studied species. PSII malfunctioning was largely associated with the observed photosynthetic down-regulation during heat wave treatments, however, its physiological recovery should be a key factor to determine species resilience to short-term extreme heat wave events.

  7. Uptake and Translocation of Manganese by Native Tree Species in a Constructed Wetland Treating Landfill Leachates

    OpenAIRE

    A. Snow; Abdel E. Ghaly

    2007-01-01

    A surface flow constructed wetland was used to treat stormwater runoff from surrounding watersheds which are comprised primarily of commercial properties and two former landfills. The uptake of manganese by red maple, white birch and red spruce trees growing under flooded soil conditions in the constructed wetland was compared to that of the same trees growing under well drained soil conditions in a nearby reference site. The seasonal variability of manganese and its distribution in different...

  8. Guild of Frugivores on three fruit-producing tree species Polyscias ...

    African Journals Online (AJOL)

    Guild of Frugivores on three fruit-producing tree species Polyscias fulva, Syzyguim Guineensis SUBSP. Bamensdae and Pouteria Altissima ) in Ngel Nyaki Forest Reserve, a Montane Forest Ecosystem in Nigeria.

  9. Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions.

    Science.gov (United States)

    Loranger, Hannah; Zotz, Gerhard; Bader, Maaike Y

    2016-01-01

    On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, tree species ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline tree populations and will depend differently on climatic conditions than adult trees. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline tree species were studied: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata and Sorbus aucuparia In addition, we monitored the germination response of three of these species to low temperatures under controlled conditions in growth chambers. The early establishment of these trees at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly species-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each species. We show that temperature and water availability are both important contributors to establishment patterns of treeline trees and hence to species-specific forms and positions of alpine treelines. The observed idiosyncratic species responses highlight the need for studies including several species and life-stages to create predictive power concerning future treeline dynamics. © The Authors 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

  10. Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species

    International Nuclear Information System (INIS)

    Calder, W.J.; Lifferth, G.; Clair, S.B.S.; Moritz, M.A.

    2010-01-01

    Smoke from forest fires can persist in the environment for weeks and while there is a substantial amount of literature examining the effects of smoke exposure on seed germination, the effects of smoke on leaf function are nearly un investigated. The objective of this study was to compare growth and primary and secondary metabolic responses of deciduous angiosperm and evergreen conifer tree species to short smoke exposure. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.

  11. Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species

    Directory of Open Access Journals (Sweden)

    W. John Calder

    2010-01-01

    Full Text Available Smoke from forest fires can persist in the environment for weeks and while there is a substantial amount of literature examining the effects of smoke exposure on seed germination, the effects of smoke on leaf function are nearly uninvestigated. The objective of this study was to compare growth and primary and secondary metabolic responses of deciduous angiosperm and evergreen conifer tree species to short smoke exposure. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.

  12. Soil greenhouse gas fluxes from different tree species on Taihang Mountain, North China

    Science.gov (United States)

    Liu, X. P.; Zhang, W. J.; Hu, C. S.; Tang, X. G.

    2014-03-01

    The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how tree species, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variation in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each tree species. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 to April 2012. Soil CO2 emissions from all tree species were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil organic carbon and total N were significantly positively correlated with CO2 and N2O fluxes. Soil bulk density was significantly negatively correlated with CO2 and N2O fluxes. Soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter significantly decreased in CO2 emissions and CH4 uptakes. Soils in six tree species acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, soils in all tree

  13. Gene-Tree Reconciliation with MUL-Trees to Resolve Polyploidy Events.

    Science.gov (United States)

    Gregg, W C Thomas; Ather, S Hussain; Hahn, Matthew W

    2017-11-01

    Polyploidy can have a huge impact on the evolution of species, and it is a common occurrence, especially in plants. The two types of polyploids-autopolyploids and allopolyploids-differ in the level of divergence between the genes that are brought together in the new polyploid lineage. Because allopolyploids are formed via hybridization, the homoeologous copies of genes within them are at least as divergent as orthologs in the parental species that came together to form them. This means that common methods for estimating the parental lineages of allopolyploidy events are not accurate, and can lead to incorrect inferences about the number of gene duplications and losses. Here, we have adapted an algorithm for topology-based gene-tree reconciliation to work with multi-labeled trees (MUL-trees). By definition, MUL-trees have some tips with identical labels, which makes them a natural representation of the genomes of polyploids. Using this new reconciliation algorithm we can: accurately place allopolyploidy events on a phylogeny, identify the parental lineages that hybridized to form allopolyploids, distinguish between allo-, auto-, and (in most cases) no polyploidy, and correctly count the number of duplications and losses in a set of gene trees. We validate our method using gene trees simulated with and without polyploidy, and revisit the history of polyploidy in data from the clades including both baker's yeast and bread wheat. Our re-analysis of the yeast data confirms the allopolyploid origin and parental lineages previously identified for this group. The method presented here should find wide use in the growing number of genomes from species with a history of polyploidy. [Polyploidy; reconciliation; whole-genome duplication.]. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Video Segmentation Using Fast Marching and Region Growing Algorithms

    Directory of Open Access Journals (Sweden)

    Eftychis Sifakis

    2002-04-01

    Full Text Available The algorithm presented in this paper is comprised of three main stages: (1 classification of the image sequence and, in the case of a moving camera, parametric motion estimation, (2 change detection having as reference a fixed frame, an appropriately selected frame or a displaced frame, and (3 object localization using local colour features. The image sequence classification is based on statistical tests on the frame difference. The change detection module uses a two-label fast marching algorithm. Finally, the object localization uses a region growing algorithm based on the colour similarity. Video object segmentation results are shown using the COST 211 data set.

  15. Contact zoonosis related to aquaculture: a growing concern

    Science.gov (United States)

    Aquaculture develops fast worldwide, with new cultured species and increased global transport of live aquaculture products. There is a growing recognition of zoonotic disease agents causing epidemics and carrier states in cultured fish and shellfish, especially from warm water systems, transmitted t...

  16. The diversity and richness of tree species of Tambang Sawah forest Kerinci-Seblat National Park Sumatra Indonesia

    Directory of Open Access Journals (Sweden)

    Agus Susatya

    2010-12-01

    Full Text Available The conservation of tropical ecosystem is increasingly relevant as the recent global warming and climate change generate serious impacts on human life. Tropical forest becomes an important ecosystem to fight global warming due to its capability to sequester atmospheric carbon and to mitigate climate change. It is very unfortunate that such a vital ecosystem has been severely subjected to conversion to both plantations and illegal loggings. The tropical ecosystem has long been recognized to have high species diversity, but very few individual trees per species. The latter is almost ignored, even though can certainly bring serious difficulties on tree conservation. The objectives of the research were to know the tree community structure of Tambang Sawah Forest, Kerinci-Seblat National Park, and to determine the rareness of tree species. A plot of 1 ha was established at Tambang Sawah, Kerinci-Seblat National Park, Lebong Regency. All trees with BDH of > 5 cm were collected their herbarium specimens, and identifi ed. The results showed that Tambang Sawah forest consists of 42 families, 94 genera, and 185 tree species/ha. It has 19.51% (8 families, and 26.82% (10 families respectively categorized as very rare and rare. The pattern also occurs at genus level, where both categories contribute to 81.91% (78 genera of the total genera. In species level, both are respectively 90 and 28 species, and altogether contribute to 63.78% of the total species. These values appeared higher than that of the other forests in Bengkulu. Across taxon level, very rare and rare categories appeared to be an ecological attribute in Sumatran forests. This implies that the loss of single tree can cause the loss of entire family. The conservation works even turn into more difficult, because tropical trees are commonly diocious, even bisexual trees, they tend to be self-incompatible, and out-crossed, and required at least 200 mature trees to ensure sexual regeneration and to

  17. Foliage biomass qualitative indices of selected forest forming tree species in Ukrainian Steppe

    Directory of Open Access Journals (Sweden)

    Sytnyk Svitlana

    2017-06-01

    Full Text Available Our study objective was research on the assimilation component of aboveground biomass of trees and its correlation with mensurational indices of trees (age, diameter and height in stands of the main forest forming species in the Ukrainian Northern Steppe zone - Pinus sylvestris L. (Scots pine and Robinia pseudoacacia L. (Black locust. The research was carried out in forest stands subordinated to the State Agency of Forest Resources of Ukraine. We used experimental data collected on sample plots established during years 2014-2016. The main research results prove that the foliage share in the tree greenery biomass structure had a wide range of values. For both investigated species, a positive correlation was found between the dry matter content in the tree foliage and the tree age, height and diameter. The foliage share in tree greenery biomass decreased with increasing mensurational index values. Correlation analysis revealed linear relationships between the mensurational indices and the discussed aboveground live biomass parameters. The closest correlation was observed between the stand age, mean stand diameter, mean stand height and dry matter content in the foliage.

  18. Tree Species with Photosynthetic Stems Have Greater Nighttime Sap Flux

    Directory of Open Access Journals (Sweden)

    Xia Chen

    2018-01-01

    Full Text Available An increasing body of evidence has shown that nighttime sap flux occurs in most plants, but the physiological implications and regulatory mechanism are poorly known. The significance of corticular photosynthesis has received much attention during the last decade, however, the knowledge of the relationship between corticular photosynthesis and nocturnal stem sap flow is limited at present. In this study, we divided seven tree species into two groups according to different photosynthetic capabilities: trees of species with (Castanopsis hystrix, Michelia macclurei, Eucalyptus citriodora, and Eucalyptus grandis × urophylla and without (Castanopsis fissa, Schima superba, and Acacia auriculiformis photosynthetic stems, and the sap flux (Js and chlorophyll fluorescence parameters for these species were measured. One-way ANOVA analysis showed that the Fv/Fm (Maximum photochemical quantum yield of PSII and ΦPSII (effective photochemical quantum yield of PSII values were lower in non-photosynthetic stem species compared to photosynthetic stem species. The linear regression analysis showed that Js,d (daytime sap flux and Js,n (nighttime sap flux of non-photosynthetic stem species was 87.7 and 60.9% of the stem photosynthetic species. Furthermore, for a given daytime transpiration water loss, total nighttime sap flux was higher in species with photosynthetic stems (SlopeSMA = 2.680 than in non-photosynthetic stems species (SlopeSMA = 1.943. These results mean that stem corticular photosynthesis has a possible effect on the nighttime water flow, highlighting the important eco-physiological relationship between nighttime sap flux and corticular photosynthesis.

  19. Tree Species with Photosynthetic Stems Have Greater Nighttime Sap Flux

    Science.gov (United States)

    Chen, Xia; Gao, Jianguo; Zhao, Ping; McCarthy, Heather R.; Zhu, Liwei; Ni, Guangyan; Ouyang, Lei

    2018-01-01

    An increasing body of evidence has shown that nighttime sap flux occurs in most plants, but the physiological implications and regulatory mechanism are poorly known. The significance of corticular photosynthesis has received much attention during the last decade, however, the knowledge of the relationship between corticular photosynthesis and nocturnal stem sap flow is limited at present. In this study, we divided seven tree species into two groups according to different photosynthetic capabilities: trees of species with (Castanopsis hystrix, Michelia macclurei, Eucalyptus citriodora, and Eucalyptus grandis × urophylla) and without (Castanopsis fissa, Schima superba, and Acacia auriculiformis) photosynthetic stems, and the sap flux (Js) and chlorophyll fluorescence parameters for these species were measured. One-way ANOVA analysis showed that the Fv/Fm (Maximum photochemical quantum yield of PSII) and ΦPSII (effective photochemical quantum yield of PSII) values were lower in non-photosynthetic stem species compared to photosynthetic stem species. The linear regression analysis showed that Js,d (daytime sap flux) and Js,n (nighttime sap flux) of non-photosynthetic stem species was 87.7 and 60.9% of the stem photosynthetic species. Furthermore, for a given daytime transpiration water loss, total nighttime sap flux was higher in species with photosynthetic stems (SlopeSMA = 2.680) than in non-photosynthetic stems species (SlopeSMA = 1.943). These results mean that stem corticular photosynthesis has a possible effect on the nighttime water flow, highlighting the important eco-physiological relationship between nighttime sap flux and corticular photosynthesis. PMID:29416547

  20. Factors influencing non-native tree species distribution in urban landscapes

    Science.gov (United States)

    Wayne C. Zipperer

    2010-01-01

    Non-native species are presumed to be pervasive across the urban landscape. Yet, we actually know very little about their actual distribution. For this study, vegetation plot data from Syracuse, NY and Baltimore, MD were used to examine non-native tree species distribution in urban landscapes. Data were collected from remnant and emergent forest patches on upland sites...

  1. Short-term light and leaf photosynthetic dynamics affect estimates of daily understory photosynthesis in four tree species.

    Science.gov (United States)

    Naumburg, Elke; Ellsworth, David S

    2002-04-01

    Instantaneous measurements of photosynthesis are often implicitly or explicitly scaled to longer time frames to provide an understanding of plant performance in a given environment. For plants growing in a forest understory, results from photosynthetic light response curves in conjunction with diurnal light data are frequently extrapolated to daily photosynthesis (A(day)), ignoring dynamic photosynthetic responses to light. In this study, we evaluated the importance of two factors on A(day) estimates: dynamic physiological responses to photosynthetic photon flux density (PPFD); and time-resolution of the PPFD data used for modeling. We used a dynamic photosynthesis model to investigate how these factors interact with species-specific photosynthetic traits, forest type, and sky conditions to affect the accuracy of A(day) predictions. Increasing time-averaging of PPFD significantly increased the relative overestimation of A(day) similarly for all study species because of the nonlinear response of photosynthesis to PPFD (15% with 5-min PPFD means). Depending on the light environment characteristics and species-specific dynamic responses to PPFD, understory tree A(day) can be overestimated by 6-42% for the study species by ignoring these dynamics. Although these overestimates decrease under cloudy conditions where direct sunlight and consequently understory sunfleck radiation is reduced, they are still significant. Within a species, overestimation of A(day) as a result of ignoring dynamic responses was highly dependent on daily sunfleck PPFD and the frequency and irradiance of sunflecks. Overall, large overestimates of A(day) in understory trees may cause misleading inferences concerning species growth and competition in forest understories with sunlight. We conclude that comparisons of A(day) among co-occurring understory species in deep shade will be enhanced by consideration of sunflecks by using high-resolution PPFD data and understanding the physiological

  2. Tree growth-climate relationships in a forest-plot network on Mediterranean mountains.

    Science.gov (United States)

    Fyllas, Nikolaos M; Christopoulou, Anastasia; Galanidis, Alexandros; Michelaki, Chrysanthi Z; Dimitrakopoulos, Panayiotis G; Fulé, Peter Z; Arianoutsou, Margarita

    2017-11-15

    In this study we analysed a novel tree-growth dataset, inferred from annual ring-width measurements, of 7 forest tree species from 12 mountain regions in Greece, in order to identify tree growth - climate relationships. The tree species of interest were: Abies cephalonica, Abies borisii-regis, Picea abies, Pinus nigra, Pinus sylvestris, Fagus sylvatica and Quercus frainetto growing across a gradient of climate conditions with mean annual temperature ranging from 5.7 to 12.6°C and total annual precipitation from 500 to 950mm. In total, 344 tree cores (one per tree) were analysed across a network of 20 study sites. We found that water availability during the summer period (May-August) was a strong predictor of interannual variation in tree growth for all study species. Across species and sites, annual tree growth was positively related to summer season precipitation (P SP ). The responsiveness of annual growth to P SP was tightly related to species and site specific measurements of instantaneous photosynthetic water use efficiency (WUE), suggesting that the growth of species with efficient water use is more responsive to variations in precipitation during the dry months of the year. Our findings support the importance of water availability for the growth of mountainous Mediterranean tree species and highlight that future reductions in precipitation are likely to lead to reduced tree-growth under climate change conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Economic Valuation of Urban Trees: Ribnjak Park Case Study, Zagreb

    Directory of Open Access Journals (Sweden)

    Karlo Beljan

    2015-06-01

    Full Text Available Background and Purpose: Population growth, urbanisation and technological development are creating a growing need for urban forests and parks, which are becoming green oases for recreation and relaxation. Apart from the sociological and economic components, urban forest valuation is presented through tourism, the market value of main and secondary forest products, and the growing value of real estate in the vicinity of green areas. Environmental economics explores the optimal ratio between the costs and the benefits received from the investment in the environment. The aim of this research is monetary valuation of urban trees. Materials and Methods: A Danish model for tree value determination was applied in Ribnjak Park as a case study. The model is based on tree growing costs and the present value. It is limited by the subjective aesthetic tree value estimation, but it is used in Europe because of its practicality. Individual tree value estimation is used because of the tree damage from vehicles or new residential buildings. The method is suitable for individual trees or groups of trees, but it is not appropriate for forest stands. Twenty random selected trees from nine different tree species have been analysed in the park. Diameter at breast height, tree height, expected age, aesthetic value and location were recorded for each tree. Furthermore, ecological, social and health tree values were taken into account separately with the calculation of points. Results: According to the evaluation, the average monetary value of one tree in Ribnjak Park is 542 EUR. The average diameter at breast height is 57.86 cm with the average age of 96.14 years. Plane trees have the highest value in comparison to other sampled species. Conclusions: Tree values vary depending on age, dimension or aesthetic values. The disadvantage of this method is in the estimation of very old tree value and in high involvement of personal estimation, which creates an opportunity

  4. Degree of susceptibility of industrial gases of tree and shrub species

    Energy Technology Data Exchange (ETDEWEB)

    Dobrovoljskii, I A

    1952-01-01

    The trees and shrubs of the iron smelting region of Krivoi Rog, in the Ukraine, were surveyed to determine susceptibility to air pollution damage. Most of the observations were made in parks and green belts in industrial areas. A classification of tree and shrub species is presented; they are separated into three classes according to their susceptibility to air pollutant injury.

  5. Fast Construction of Near Parsimonious Hybridization Networks for Multiple Phylogenetic Trees.

    Science.gov (United States)

    Mirzaei, Sajad; Wu, Yufeng

    2016-01-01

    Hybridization networks represent plausible evolutionary histories of species that are affected by reticulate evolutionary processes. An established computational problem on hybridization networks is constructing the most parsimonious hybridization network such that each of the given phylogenetic trees (called gene trees) is "displayed" in the network. There have been several previous approaches, including an exact method and several heuristics, for this NP-hard problem. However, the exact method is only applicable to a limited range of data, and heuristic methods can be less accurate and also slow sometimes. In this paper, we develop a new algorithm for constructing near parsimonious networks for multiple binary gene trees. This method is more efficient for large numbers of gene trees than previous heuristics. This new method also produces more parsimonious results on many simulated datasets as well as a real biological dataset than a previous method. We also show that our method produces topologically more accurate networks for many datasets.

  6. Mapping growing stock volume and forest live biomass: a case study of the Polissya region of Ukraine

    Science.gov (United States)

    Bilous, Andrii; Myroniuk, Viktor; Holiaka, Dmytrii; Bilous, Svitlana; See, Linda; Schepaschenko, Dmitry

    2017-10-01

    Forest inventory and biomass mapping are important tasks that require inputs from multiple data sources. In this paper we implement two methods for the Ukrainian region of Polissya: random forest (RF) for tree species prediction and k-nearest neighbors (k-NN) for growing stock volume and biomass mapping. We examined the suitability of the five-band RapidEye satellite image to predict the distribution of six tree species. The accuracy of RF is quite high: ~99% for forest/non-forest mask and 89% for tree species prediction. Our results demonstrate that inclusion of elevation as a predictor variable in the RF model improved the performance of tree species classification. We evaluated different distance metrics for the k-NN method, including Euclidean or Mahalanobis distance, most similar neighbor (MSN), gradient nearest neighbor, and independent component analysis. The MSN with the four nearest neighbors (k = 4) is the most precise (according to the root-mean-square deviation) for predicting forest attributes across the study area. The k-NN method allowed us to estimate growing stock volume with an accuracy of 3 m3 ha-1 and for live biomass of about 2 t ha-1 over the study area.

  7. Tree phyllosphere bacterial communities: exploring the magnitude of intra- and inter-individual variation among host species

    Directory of Open Access Journals (Sweden)

    Isabelle Laforest-Lapointe

    2016-08-01

    Full Text Available Background The diversity and composition of the microbial community of tree leaves (the phyllosphere varies among trees and host species and along spatial, temporal, and environmental gradients. Phyllosphere community variation within the canopy of an individual tree exists but the importance of this variation relative to among-tree and among-species variation is poorly understood. Sampling techniques employed for phyllosphere studies include picking leaves from one canopy location to mixing randomly selected leaves from throughout the canopy. In this context, our goal was to characterize the relative importance of intra-individual variation in phyllosphere communities across multiple species, and compare this variation to inter-individual and interspecific variation of phyllosphere epiphytic bacterial communities in a natural temperate forest in Quebec, Canada. Methods We targeted five dominant temperate forest tree species including angiosperms and gymnosperms: Acer saccharum, Acer rubrum, Betula papyrifera, Abies balsamea and Picea glauca. For one randomly selected tree of each species, we sampled microbial communities at six distinct canopy locations: bottom-canopy (1–2 m height, the four cardinal points of mid-canopy (2–4 m height, and the top-canopy (4–6 m height. We also collected bottom-canopy leaves from five additional trees from each species. Results Based on an analysis of bacterial community structure measured via Illumina sequencing of the bacterial 16S gene, we demonstrate that 65% of the intra-individual variation in leaf bacterial community structure could be attributed to the effect of inter-individual and inter-specific differences while the effect of canopy location was not significant. In comparison, host species identity explains 47% of inter-individual and inter-specific variation in leaf bacterial community structure followed by individual identity (32% and canopy location (6%. Discussion Our results suggest that

  8. Prediction of Dominant Forest Tree Species Using QuickBird and Environmental Data

    Directory of Open Access Journals (Sweden)

    Azadeh Abdollahnejad

    2017-02-01

    Full Text Available Modelling the spatial distribution of plants is one of the indirect methods for predicting the properties of plants and can be defined based on the relationship between the spatial distribution of vegetation and environmental variables. In this article, we introduce a new method for the spatial prediction of the dominant trees and species, through a combination of environmental and satellite data. Based on the basal area factor (BAF frequency for each tree species in a total of 518 sample plots, the dominant tree species were determined for each plot. Also, topographical maps of primary and secondary properties were prepared using the digital elevation model (DEM. Categories of soil and the climate maps database of the Doctor Bahramnia Forestry Plan were extracted as well. After pre-processing and processing of spectral data, the pixel values at the sample locations in all the independent factors such as spectral and non-spectral data, were extracted. The modelling rates of tree and shrub species diversity using data mining algorithms of 80% of the sampling plots were taken. Assessment of model accuracy was conducted using 20% of samples and evaluation criteria. Random forest (RF, support vector machine (SVM and k-nearest neighbor (k-NN algorithms were used for spatial distribution modelling of dominant species groups using environmental and spectral variables from 80% of the sample plots. Results showed physiographic factors, especially altitude in combination with soil and climate factors as the most important variables in the distribution of species, while the best model was created by the integration of physiographic factors (in combination with soil and climate with an overall accuracy of 63.85%. In addition, the results of the comparison between the algorithms, showed that the RF algorithm was the most accurate in modelling the diversity.

  9. Seed rain under native and non-native tree species in the Cabo Rojo National Wildlife Refuge, Puerto Rico.

    Science.gov (United States)

    Arias Garcia, Andrea; Chinea, J Danilo

    2014-09-01

    Seed dispersal is a fundamental process in plant ecology and is of critical importance for the restoration of tropical communities. The lands of the Cabo Rojo National Wildlife Refuge (CRNWR), formerly under agriculture, were abandoned in the 1970s and colonized mainly by non-native tree species of degraded pastures. Here we described the seed rain under the most common native and non-native trees in the refuge in an attempt to determine if focal tree geographic origin (native versus non-native) influences seed dispersal. For this, seed rain was sampled for one year under the canopies of four native and four non-native tree species common in this refuge using 40 seed traps. No significant differences were found for the abundance of seeds, or their diversity, dispersing under native versus non-native focal tree species, nor under the different tree species. A significantly different seed species composition was observed reaching native versus non-native focal species. However, this last result could be more easily explained as a function of distance of the closest adults of the two most abundantly dispersed plant species to the seed traps than as a function of the geographic origin of the focal species. We suggest to continue the practice of planting native tree species, not only as a way to restore the community to a condition similar to the original one, but also to reduce the distances needed for effective dispersal.

  10. Use of tree species by White-throated treerunner (Pygarrhichas albogularis King) in a secondary native forest of southern Chile

    OpenAIRE

    Gantz, Alberto; Yañez, Miguel; Orellana, José I.; Sade, Soraya; Valdivia, Carlos E.

    2015-01-01

    ABSTRACT In forest ecosystems, numerous species of insectivorous birds use certain tree species as feeding and nesting substrates. Between 2009 and 2010, the use of different floristic components as feeding substrate by the Pygarrhichas albogularis King, 1831 was evaluated in a southern Chilean secondary native forest. From a total of 13 trees and bush species, six tree species were used by P. albogularis as a feeding substrate. Tree use was limited to intermediate heights (11-20 m) and, main...

  11. Unusual fast-growing ovarian cystic teratoma during pregnancy presenting with intracystic fat "floating balls" appearance.

    Science.gov (United States)

    Donnadieu, Anne Claire; Deffieux, Xavier; Le Ray, Camille; Mordefroid, Marie; Frydman, René; Fernandez, Hervé

    2006-12-01

    A large ovarian cyst was diagnosed at 22 weeks' of gestation in a 32-year-old woman. The ultrasonographic appearance of the ovarian cyst was unusual with multiple mobile, spherical echogenic structures floating in the cystic mass, called intracystic "fat balls." Right adnexectomy was performed by laparotomy at 28 weeks' of gestation, because of rapid growth and overall size exceeding 20 cm. Pathological examination confirmed ovarian cystic teratoma. Usually, dermoid cysts are slow-growing, even in premenopausal women. The exact mechanism related to the fast growth during pregnancy is unknown. It could be related to an unusual pattern of estrogen (E)/P receptors expression in the cystic teratoma. This case shows that a fast-growing, mature ovarian cystic teratoma may occur during pregnancy.

  12. Beyond Tree Throw: Wind, Water, Rock and the Mechanics of Tree-Driven Bedrock Physical Weathering

    Science.gov (United States)

    Marshall, J. A.; Anderson, R. S.; Dawson, T. E.; Dietrich, W. E.; Minear, J. T.

    2017-12-01

    Tree throw is often invoked as the dominant process in converting bedrock to soil and thus helping to build the Critical Zone (CZ). In addition, observations of tree roots lifting sidewalk slabs, occupying cracks, and prying slabs of rock from cliff faces have led to a general belief in the power of plant growth forces. These common observations have led to conceptual models with trees at the center of the soil genesis process. This is despite the observation that tree throw is rare in many forested settings, and a dearth of field measurements that quantify the magnitude of growth forces. While few trees blow down, every tree grows roots, inserting many tens of percent of its mass below ground. Yet we lack data quantifying the role of trees in both damaging bedrock and detaching it (and thus producing soil). By combing force measurements at the tree-bedrock interface with precipitation, solar radiation, wind speed, and wind-driven tree sway data we quantified the magnitude and frequency of tree-driven soil-production mechanisms from two contrasting climatic and lithologic regimes (Boulder and Eel Creek CZ Observatories). Preliminary data suggests that in settings with relatively thin soils, trees can damage and detach rock due to diurnal fluctuations, wind response and rainfall events. Surprisingly, our data suggests that forces from roots and trunks growing against bedrock are insufficient to pry rock apart or damage bedrock although much more work is needed in this area. The frequency, magnitude and style of wind-driven tree forces at the bedrock interface varies considerably from one to another species. This suggests that tree properties such as mass, elasticity, stiffness and branch structure determine whether trees respond to gusts big or small, move at the same frequency as large wind gusts, or are able to self-dampen near-ground sway response to extended wind forces. Our measurements of precipitation-driven and daily fluctuations in root pressures exerted on

  13. Radionuclide levels in vegetation growing on uranium tailings, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    Pave, N.K.; Cloutier, N.R.; Lim, T.P.

    1985-01-01

    In Elliot Lake, Ontario, Canada, most of the inactive uranium tailings have been reclaimed by revegetation where a thick vegetation cover has been established. The surface amendments have also prompted volunteer growth of various species of local trees and shrubs on tailings. Radionuclide levels were measured in various tissues of grasses, legumes and trees growing on uranium tailings at different sites. Lower Th than Ra and Pb levels in tailings substrate were believed to be the cause for the relatively lower Th levels measured in vegetation when compared to Ra and Pb concentrations. No correlation was observed between the level of a given radionuclide in tailings and in the vegetation growing on that tailings

  14. Relationship between Leaf Surface Characteristics and Particle Capturing Capacities of Different Tree Species in Beijing

    Directory of Open Access Journals (Sweden)

    Weikang Zhang

    2017-03-01

    Full Text Available Leaf surface is a multifunctional interface between a plant and its environment, which affects both ecological and biological processes. Leaf surface topography directly affects microhabitat availability and ability for deposition. In this study, atomic force microscopy (AFM and the resuspended particulate matter method were applied to evaluate the adsorptive capacity of the leaf surface. Patterns of particulate‐capturing capacities in different tree species and the effect of leaf surface features on these capacities were explored. Results indicated the following: (1 more total suspended particles (TSP per unit leaf area were captured by coniferous tree species than by broad‐leaved tree species in a particular order—i.e., Pinus tabuliformis > Pinus bungeana > Salix matsudana > Acer truncatum > Ginkgo biloba > Populus tomentosa; (2 Significant seasonal variation in particulate‐capturing capacities were determined. During the observation period, the broad‐leaved tree species capturing TSP and coarse particulate matter (PM10 clearly exhibited a ∩‐shape pattern— that is, increasing initially and later on decreasing; meanwhile, the ∩‐shape pattern was not clearly shown in P. tabuliformis and P. bungeana. However, no obvious patterns in the absorption of fine particulate matter (PM2.5 were found in the tested tree species; (3 The leaf surface topography, as observed by AFM and scanning electron microscopy, revealed that the broad‐leaved tree exhibits a good correlation between micro‐roughness of leaf surfaces and density of particles settling on leaf surfaces over time. However, the main factors affecting the adsorptive capacities of the leaves in coniferous trees are the number of stomata as well as the amount of epicuticular wax and the properties of the cuticle in different seasons.

  15. Spatial distribution of seeds and seedlings of two tropical tree species: Is there correspondence between patterns?

    International Nuclear Information System (INIS)

    Parrado Rosselli, Angela

    2007-01-01

    The spatial patterns of seed and seedling distribution relative to parent trees (seed and seedling shadow, respectively) were studied for Dacryodes chimantensis (Burseraceae) and Brosimum utile (Moraceae), two common tree species of terra firme forests of Colombian Amazonia. The general objective was to assess whether the patterns imposed by seed dispersal change or persist in subsequent life stages occurring during the transition from seeds/saplings to adult stages. Seed and seedling shadows on the ground were characterized for each tree species along four 50-m radial transects from the base of the parent tree. Causes of seed and seedling predation as a function of distance to the parent tree were determined, as well as the spatial consistency between life stages. Results showed that seed density of both Dacryodes and Brosimum declined leptokurtically with distance, and it was skewed towards the parent tree. However, seed density was more skewed and leptokurtic in Dacryodes than in Brosimum. The overall trend was maintained in the seedling stage of both species and was positively correlated with the distribution patterns of seeds. Seed and seedling predation were positively correlated with density and negatively correlated with the distance from the parent tree. Factors that could be generating the high consistency between the spatial patterns of seed and seedling distribution are discussed, as well as its implications in the population structure of both species and the debate on the factors that influence the spatial distribution of plant species in tropical rain forests.

  16. Effects of species biological traits and environmental heterogeneity on simulated tree species distribution shifts under climate change

    Science.gov (United States)

    Wen J. Wang; Hong S. He; Frank R. Thompson; Martin A. Spetich; Jacob S. Fraser

    2018-01-01

    Demographic processes (fecundity, dispersal, colonization, growth, and mortality) and their interactions with environmental changes are notwell represented in current climate-distribution models (e.g., niche and biophysical process models) and constitute a large uncertainty in projections of future tree species distribution shifts.We investigate how species biological...

  17. Mycorrhizal association of some agroforestry tree species in two ...

    African Journals Online (AJOL)

    Administrator

    2011-05-05

    May 5, 2011 ... Key words: Arbuscular mycorrhizal fungi, agroforestry tree species. INTRODUCTION ... plant growth hormones, protection of host roots from pathogens .... interactions between fungal strains and soil than between the fungus ... phosphorus and drought stress on the growth of Acacic nilotica and. Leucaena ...

  18. Crop tree release options for young hardwood stands in North Carolina

    Science.gov (United States)

    Jamie L. Schuler; Daniel J. Robison

    2006-01-01

    Harvesting southern hardwood forests using even-aged reproduction methods commonly regenerate new stands with 20,000 to 50,000 stems per acre. Overstocking and an overabundance of non-commercial tree species are considered major constraints to growing productive and valuable hardwoods. Crop tree release practices have been promoted as an efficient way of thinning young...

  19. Comprehensive database of diameter-based biomass regressions for North American tree species

    Science.gov (United States)

    Jennifer C. Jenkins; David C. Chojnacky; Linda S. Heath; Richard A. Birdsey

    2004-01-01

    A database consisting of 2,640 equations compiled from the literature for predicting the biomass of trees and tree components from diameter measurements of species found in North America. Bibliographic information, geographic locations, diameter limits, diameter and biomass units, equation forms, statistical errors, and coefficients are provided for each equation,...

  20. Heavy metals in emergent trees and pioneers from tropical forest with special reference to forest fires and local pollution sources in Sarawak, Malaysia.

    Science.gov (United States)

    Breulman, G; Markert, B; Weckert, V; Herpin, U; Yoneda, R; Ogino, K

    2002-02-21

    Leaf samples of tropical trees, i.e. Dryobalanops lanceolata (Kapur paji), Dipterocarpaceae and Macaranga spp. (Mahang), Euphorbiaceae were analyzed for 21 chemical elements. The pioneer Macaranga spp. exhibited higher concentrations for the majority of elements compared to the emergent species of Dryobalanops lanceolata, which was attributed to the higher physiological activity of the fast growing pioneer species compared to emergent trees. Lead showed rather high concentrations in several samples from the Bakam re-forestation site. This is suggested to be caused by emissions through brick manufacturing and related activities in the vicinity. A comparison of Dryobalanops lanceolata samples collected in 1993, 1995 and 1997 in the Lambir Hills National Park revealed that certain heavy metals, i.e. Co, Cu, Mn, Ni, Pb and Ti showed higher values in 1997 compared to the previous years, which could indicate an atmospheric input from the haze caused by the extensive forest fires raging in Borneo and other parts of Southeast Asia.

  1. Species-specific growth responses to climate variations in understory trees of a Central African rain forest

    NARCIS (Netherlands)

    Couralet, C.; Sterck, F.J.; Sass-Klaassen, U.; Acker, Van J.; Beekman, H.

    2010-01-01

    Basic knowledge of the relationships between tree growth and environmental variables is crucial for understanding forest dynamics and predicting vegetation responses to climate variations. Trees growing in tropical areas with a clear seasonality in rainfall often form annual growth rings. In the

  2. Applying species-tree analyses to deep phylogenetic histories: challenges and potential suggested from a survey of empirical phylogenetic studies.

    Science.gov (United States)

    Lanier, Hayley C; Knowles, L Lacey

    2015-02-01

    Coalescent-based methods for species-tree estimation are becoming a dominant approach for reconstructing species histories from multi-locus data, with most of the studies examining these methodologies focused on recently diverged species. However, deeper phylogenies, such as the datasets that comprise many Tree of Life (ToL) studies, also exhibit gene-tree discordance. This discord may also arise from the stochastic sorting of gene lineages during the speciation process (i.e., reflecting the random coalescence of gene lineages in ancestral populations). It remains unknown whether guidelines regarding methodologies and numbers of loci established by simulation studies at shallow tree depths translate into accurate species relationships for deeper phylogenetic histories. We address this knowledge gap and specifically identify the challenges and limitations of species-tree methods that account for coalescent variance for deeper phylogenies. Using simulated data with characteristics informed by empirical studies, we evaluate both the accuracy of estimated species trees and the characteristics associated with recalcitrant nodes, with a specific focus on whether coalescent variance is generally responsible for the lack of resolution. By determining the proportion of coalescent genealogies that support a particular node, we demonstrate that (1) species-tree methods account for coalescent variance at deep nodes and (2) mutational variance - not gene-tree discord arising from the coalescent - posed the primary challenge for accurate reconstruction across the tree. For example, many nodes were accurately resolved despite predicted discord from the random coalescence of gene lineages and nodes with poor support were distributed across a range of depths (i.e., they were not restricted to a particular recent divergences). Given their broad taxonomic scope and large sampling of taxa, deep level phylogenies pose several potential methodological complications including

  3. Tree Species with Photosynthetic Stems Have Greater Nighttime Sap Flux.

    Science.gov (United States)

    Chen, Xia; Gao, Jianguo; Zhao, Ping; McCarthy, Heather R; Zhu, Liwei; Ni, Guangyan; Ouyang, Lei

    2018-01-01

    An increasing body of evidence has shown that nighttime sap flux occurs in most plants, but the physiological implications and regulatory mechanism are poorly known. The significance of corticular photosynthesis has received much attention during the last decade, however, the knowledge of the relationship between corticular photosynthesis and nocturnal stem sap flow is limited at present. In this study, we divided seven tree species into two groups according to different photosynthetic capabilities: trees of species with ( Castanopsis hystrix, Michelia macclurei, Eucalyptus citriodora , and Eucalyptus grandis × urophylla ) and without ( Castanopsis fissa, Schima superba , and Acacia auriculiformis ) photosynthetic stems, and the sap flux ( J s ) and chlorophyll fluorescence parameters for these species were measured. One-way ANOVA analysis showed that the F v / F m (Maximum photochemical quantum yield of PSII) and Φ PSII (effective photochemical quantum yield of PSII) values were lower in non-photosynthetic stem species compared to photosynthetic stem species. The linear regression analysis showed that J s,d (daytime sap flux) and J s,n (nighttime sap flux) of non-photosynthetic stem species was 87.7 and 60.9% of the stem photosynthetic species. Furthermore, for a given daytime transpiration water loss, total nighttime sap flux was higher in species with photosynthetic stems (Slope SMA = 2.680) than in non-photosynthetic stems species (Slope SMA = 1.943). These results mean that stem corticular photosynthesis has a possible effect on the nighttime water flow, highlighting the important eco-physiological relationship between nighttime sap flux and corticular photosynthesis.

  4. Carbon and nitrogen in forest floor and mineral soil under six common European tree species

    DEFF Research Database (Denmark)

    Vesterdal, Lars; Schmidt, Inger K.; Callesen, Ingeborg

    2007-01-01

    The knowledge of tree species effects on soil C and N pools is scarce, particularly for European deciduous tree species. We studied forest floor and mineral soil carbon and nitrogen under six common European tree species in a common garden design replicated at six sites in Denmark. Three decades...... on forest floor C and N content was primarily attributed to large differences in turnover rates as indicated by fractional annual loss of forest floor C and N. The C/N ratio of foliar litterfall was a good indicator of forest floor C and N contents, fractional annual loss of forest floor C and N...

  5. Silviculture and the assessment of climate change genetic risk for southern Appalachian forest tree species

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane

    2012-01-01

    Changing climate conditions and increasing insect and pathogen infestations will increase the likelihood that forest trees could experience population-level extirpation or species-level extinction during the next century. Gene conservation and silvicultural efforts to preserve forest tree genetic diversity present a particular challenge in species-rich regions such as...

  6. Stem water storage in five coexisting temperate broad-leaved tree species: significance, temporal dynamics and dependence on tree functional traits.

    Science.gov (United States)

    Köcher, Paul; Horna, Viviana; Leuschner, Christoph

    2013-08-01

    The functional role of internal water storage is increasingly well understood in tropical trees and conifers, while temperate broad-leaved trees have only rarely been studied. We examined the magnitude and dynamics of the use of stem water reserves for transpiration in five coexisting temperate broad-leaved trees with largely different morphology and physiology (genera Fagus, Fraxinus, Tilia, Carpinus and Acer). We expected that differences in water storage patterns would mostly reflect species differences in wood anatomy (ring vs. diffuse-porous) and wood density. Sap flux density was recorded synchronously at five positions along the root-to-branch flow path of mature trees (roots, three stem positions and branches) with high temporal resolution (2 min) and related to stem radius changes recorded with electronic point dendrometers. The daily amount of stored stem water withdrawn for transpiration was estimated by comparing the integrated flow at stem base and stem top. The temporal coincidence of flows at different positions and apparent time lags were examined by cross-correlation analysis. Our results confirm that internal water stores play an important role in the four diffuse-porous species with estimated 5-12 kg day(-1) being withdrawn on average in 25-28 m tall trees representing 10-22% of daily transpiration; in contrast, only 0.5-2.0 kg day(-1) was withdrawn in ring-porous Fraxinus. Wood density had a large influence on storage; sapwood area (diffuse- vs. ring-porous) may be another influential factor but its effect was not significant. Across the five species, the length of the time lag in flow at stem top and stem base was positively related to the size of stem storage. The stem stores were mostly exhausted when the soil matrix potential dropped below -0.1 MPa and daily mean vapor pressure deficit exceeded 3-5 hPa. We conclude that stem storage is an important factor improving the water balance of diffuse-porous temperate broad-leaved trees in moist

  7. Crown-level tree species classification from AISA hyperspectral imagery using an innovative pixel-weighting approach

    Science.gov (United States)

    Liu, Haijian; Wu, Changshan

    2018-06-01

    Crown-level tree species classification is a challenging task due to the spectral similarity among different tree species. Shadow, underlying objects, and other materials within a crown may decrease the purity of extracted crown spectra and further reduce classification accuracy. To address this problem, an innovative pixel-weighting approach was developed for tree species classification at the crown level. The method utilized high density discrete LiDAR data for individual tree delineation and Airborne Imaging Spectrometer for Applications (AISA) hyperspectral imagery for pure crown-scale spectra extraction. Specifically, three steps were included: 1) individual tree identification using LiDAR data, 2) pixel-weighted representative crown spectra calculation using hyperspectral imagery, with which pixel-based illuminated-leaf fractions estimated using a linear spectral mixture analysis (LSMA) were employed as weighted factors, and 3) representative spectra based tree species classification was performed through applying a support vector machine (SVM) approach. Analysis of results suggests that the developed pixel-weighting approach (OA = 82.12%, Kc = 0.74) performed better than treetop-based (OA = 70.86%, Kc = 0.58) and pixel-majority methods (OA = 72.26, Kc = 0.62) in terms of classification accuracy. McNemar tests indicated the differences in accuracy between pixel-weighting and treetop-based approaches as well as that between pixel-weighting and pixel-majority approaches were statistically significant.

  8. Construction of a Species-Level Tree of Life for the Insects and Utility in Taxonomic Profiling.

    Science.gov (United States)

    Chesters, Douglas

    2017-05-01

    Although comprehensive phylogenies have proven an invaluable tool in ecology and evolution, their construction is made increasingly challenging both by the scale and structure of publically available sequences. The distinct partition between gene-rich (genomic) and species-rich (DNA barcode) data is a feature of data that has been largely overlooked, yet presents a key obstacle to scaling supermatrix analysis. I present a phyloinformatics framework for draft construction of a species-level phylogeny of insects (Class Insecta). Matrix-building requires separately optimized pipelines for nuclear transcriptomic, mitochondrial genomic, and species-rich markers, whereas tree-building requires hierarchical inference in order to capture species-breadth while retaining deep-level resolution. The phylogeny of insects contains 49,358 species, 13,865 genera, 760 families. Deep-level splits largely reflected previous findings for sections of the tree that are data rich or unambiguous, such as inter-ordinal Endopterygota and Dictyoptera, the recently evolved and relatively homogeneous Lepidoptera, Hymenoptera, Brachycera (Diptera), and Cucujiformia (Coleoptera). However, analysis of bias, matrix construction and gene-tree variation suggests confidence in some relationships (such as in Polyneoptera) is less than has been indicated by the matrix bootstrap method. To assess the utility of the insect tree as a tool in query profiling several tree-based taxonomic assignment methods are compared. Using test data sets with existing taxonomic annotations, a tendency is observed for greater accuracy of species-level assignments where using a fixed comprehensive tree of life in contrast to methods generating smaller de novo reference trees. Described herein is a solution to the discrepancy in the way data are fit into supermatrices. The resulting tree facilitates wider studies of insect diversification and application of advanced descriptions of diversity in community studies, among

  9. Indicator species of essential forest tree species in the Burdur district.

    Science.gov (United States)

    Negiz, Mehmet Güvenç; Eser, Yunus; Kuzugüdenll, Emre; Izkan, Kürşad

    2015-01-01

    The forests of Burdur district for long have been subjected to over grazing and individual selection. As a result of this, majority of the forest areas in the district were degraded. In the district, afforestation efforts included majority of forestry implementations. It is well known that selecting suitable species plays an important role for achieving afforestation efforts. In this context, knowing the indicator species among the target species would be used in afforestation efforts, studies on the interrelationships between environmental factors and target species distribution is vital for selecting suitable species for a given area. In this study, Anatolian Black pine (Pinus nigra), Red pine (Pinus brutia), Crimean juniper (Juniperus excelsa) and Taurus cedar (Cedrus libani), essential tree species, were considered as target species. The data taken from 100 sample plots in Burdur district was used. Interspecific correlation analysis was performed to determine the positive and negative indicator species among each of the target species. As a result of ICA, 2 positive (Berberis crataegina, Juniperus oxycedrus), 2 negative (Phillyrea latifolia, Quercus coccifera) for Crimean Juniper, I positive (Juniperus oxycedrus), 3 negative (Onopordium acanthium, Fraxinus ornus, Phillyrea latifolia) for Anatolian black pine, 3 positive (Paliurus spina-christi, Quercus coccifer, Crataegus orientalis), 2 negative (Berberis crataegina, Astragalus nanus) for Red pine and 3 positive (Berberis crataegina, Rhamnus oleoides, Astragalus prusianus) 2 negative (Paliurus spina-christi, Quercus cerris) for Taurus cedarwere defined as indicator plant species. In this way, practical information was obtained for selecting the most suitable species, among the target species, for afforestation efforts in Burdur district.

  10. Climate-related genetic variation in a threatened tree species, Pinus albicaulis

    Science.gov (United States)

    Marcus V. Warwell; Ruth G. Shaw

    2017-01-01

    PREMISE OF THE STUDY: With ongoing climate change, understanding of intraspecific adaptive variation is critical for conservation and restoration of plant species. Such information is especially scarce for threatened and endangered tree species, such as Pinus albicaulis Engelm. Therefore, our principal aims were to assess adaptive variation and characterize its...

  11. Isolation and molecular characterization of Cryptococcus species isolated from pigeon nests and Eucalyptus trees.

    Science.gov (United States)

    Kamari, A; Sepahvand, A; Mohammadi, R

    2017-06-01

    Cryptococcus species are pathogenic and non-pathogenic basidiomycete yeasts that are found widely in the environment. Based on phenotypic methods, this genus has many species; however, its taxonomy is presently being re-evaluated by modern techniques. The Cryptococcus species complex includes two sibling taxa of Cryptococcus neoformans and Cryptococcus gattii . We aimed to investigate the possible distribution of Cryptococcus species in pigeon nests and Eucalyptus trees in Ilam, Iran, using molecular techniques. Two hundred and seventy-four specimens were collected from pigeon nests and Eucalyptus trees during 2016-2017. All the specimens were sub-cultured on Sabouraud Glucose Agar with chloramphenicol and bird seed agar. For molecular identification, the ITS15.8SITS2 rDNA region was amplified using the first and fourth internal transcribed spacer (ITS1 and ITS4, respectively) primers. The purified products were applied for cycle sequencing reactions in forward direction with ITS1 primer. The obtained results were analyzed with Chromas 2.3. Thirty-three out of 186 cultures (17.7%) and 11 out of 88 cultures (12.5%) were positive among pigeon nest and Eucalyptus tree specimens, respectively. Cryptococcus albidus (17.2%), C. albidus var. kuetzingii (3.4%), C. adeliensis (3.4%), C. uzbekistanensis (3.4%), and C. neoformans var. grubii (3.4%) were isolated from pigeon nests, and Cryptococcus adeliensis (25%) was the only Cryptococcus species isolated from Eucalyptus trees. The presence of pigeons and Eucalyptus trees in the vicinity of some particular places such as rest homes and hospitals should be considered as a risk factor for the immunocompromised population.

  12. Landscape patterns of species-level association between ground-beetles and overstory trees in boreal forests of western Canada (Coleoptera, Carabidae

    Directory of Open Access Journals (Sweden)

    Colin Bergeron

    2011-11-01

    Full Text Available Spatial associations between species of trees and ground-beetles (Coleoptera: Carabidae involve many indirect ecological processes, likely reflecting the function of numerous forest ecosystem components. Describing and quantifying these associations at the landscape scale is basic to the development of a surrogate-based framework for biodiversity monitoring and conservation. In this study, we used a systematic sampling grid covering 84 km2 of boreal mixedwood forest to characterize the ground-beetle assemblage associated with each tree species occurring on this landscape. Projecting the distribution of relative basal area of each tree species on the beetle ordination diagram suggests that the carabid community is structured by the same environmental factors that affects the distribution of trees, or perhaps even by trees per se. Interestingly beetle species are associated with tree species of the same rank order of abundance on this landscape, suggesting that conservation of less abundant trees will concomitantly foster conservation of less abundant beetle species. Landscape patterns of association described here are based on characteristics that can be directly linked to provincial forest inventories, providing a basis that is already available for use of tree species as biodiversity surrogates in boreal forest land management.

  13. Fire frequency and tree canopy structure influence plant species diversity in a forest-grassland ecotone

    Science.gov (United States)

    David W. Peterson; Peter B. Reich

    2008-01-01

    Disturbances and environmental heterogeneity are two factors thought to influence plant species diversity, but their effects are still poorly understood in many ecosystems. We surveyed understory vegetation and measured tree canopy cover on permanent plots spanning an experimental fire frequency gradient to test fire frequency and tree canopy effects on plant species...

  14. Tree Species Suitability to Bioswales and Impact on the Urban Water Budget.

    Science.gov (United States)

    Scharenbroch, Bryant C; Morgenroth, Justin; Maule, Brian

    2016-01-01

    Water movement between soil and the atmosphere is restricted by hardscapes in the urban environment. Some green infrastructure is intended to increase infiltration and storage of water, thus decreasing runoff and discharge of urban stormwater. Bioswales are a critical component of a water-sensitive urban design (or a low-impact urban design), and incorporation of trees into these green infrastructural components is believed to be a novel way to return stored water to the atmosphere via transpiration. This research was conducted in The Morton Arboretum's main parking lot, which is one of the first and largest green infrastructure installations in the midwestern United States. The parking lot is constructed of permeable pavers and tree bioswales. Trees in bioswales were evaluated for growth and condition and for their effects on water cycling via transpiration. Our data indicate that trees in bioswales accounted for 46 to 72% of total water outputs via transpiration, thereby reducing runoff and discharge from the parking lot. By evaluating the stomatal conductance, diameter growth, and condition of a variety of tree species in these bioswales, we found that not all species are equally suited for bioswales and that not all are equivalent in their transpiration and growth rates, thereby contributing differentially to the functional capacity of bioswales. We conclude that species with high stomatal conductance and large mature form are likely to contribute best to bioswale function. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Soil carbon accumulation and nitrogen retention traits of four tree species grown in common gardens

    DEFF Research Database (Denmark)

    Gurmesa, Geshere Abdisa; Schmidt, Inger Kappel; Gundersen, Per

    2013-01-01

    explored. Effects of four tree species on soil C and N stocks and soil water nitrate concentration below the root zone were evaluated in a common garden design replicated at eight sites in Denmark. The tree species were beech (Fagus sylvatica L.), oak (Quercus robur L.), larch (Larix leptolepis Kaempf......), and Norway spruce (Picea abies (L) Karst.). After four decades, there were significant differences in forest floor C stocks among all four species, and C stocks increased consistently in the order oak Forest floor N stocks only...... differed significantly between conifers and broadleaves. The observed differences in forest floor C and N stocks were attributed to differences in litter turnover rates among the tree species. Mineral soil C stocks were significantly higher in stands of Norway spruce than in stands of oak and beech while...

  16. Climate, Tree Growth, Forest Drought Stress, and Tree Mortality in Forests of Western North America: Long-Term Patterns and Recent Trends

    Science.gov (United States)

    Allen, C. D.; Williams, P.

    2012-12-01

    Ongoing climate changes are increasingly affecting the world's forests, particularly including high latitude and high elevation coniferous forests. Although forest growth has improved in some regions due to greater growing season length and warmth (perhaps along with increased atmospheric CO2 or N), large growth declines or increased mortality from droughts or hotter temperatures also are being observed. We present and interpret information on regional variation in climate-tree growth relationships and trends, and on patterns and trends of climate-related forest disturbances, from western North America. From 235 tree-ring chronologies in the Southwest US we show that tree-ring growth records from warmer southwestern sites are more sensitive to temperature than tree-ring growth records from cooler southwestern sites. Assessment of 59 tree-ring records from 11 species in the Cascade Mountains of the Pacific Northwest shows that trees growing in cool places respond positively to increased temperature and trees in warm places respond negatively, implying that trees historically not sensitive to temperature may become sensitive as mean temperatures warm. An analysis of 59 white spruce populations in Alaska supports the hypothesis that warming has caused tree growth to lose sensitivity to cold temperatures. Comparing ring widths to temperature during just the coldest 50% of years during the 20th century, tree growth was sensitive to cold temperatures, and this effect was strongest at the coldest sites; whereas during the warmest 50% of years, trees were not at all sensitive to cold temperatures, even at the cold sites. Drought and vapor pressure deficit are among the variables that emerge as being increasingly important to these Alaska boreal forests as mean temperatures rise. Most recently, from 346 tree-ring chronologies in the Southwest US we establish a tree-ring-based Forest Drought Stress Index (FDSI) for the three most widespread conifer species (Pinus edulis

  17. Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian tree species.

    Science.gov (United States)

    Keena, M A

    2003-02-01

    Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian tree species were examined. Seven conifer species (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf species (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host species tested were rated as intermediate in suitability, four conifer species (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf species (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 species tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the trees had a major impact on establishment, survival, and development of L. monacha on many of the tree species tested. Several of the deciduous tree species that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important tree species on which it can survive and develop, and the ability of mated females to fly and colonize new areas.

  18. MulRF: a software package for phylogenetic analysis using multi-copy gene trees.

    Science.gov (United States)

    Chaudhary, Ruchi; Fernández-Baca, David; Burleigh, John Gordon

    2015-02-01

    MulRF is a platform-independent software package for phylogenetic analysis using multi-copy gene trees. It seeks the species tree that minimizes the Robinson-Foulds (RF) distance to the input trees using a generalization of the RF distance to multi-labeled trees. The underlying generic tree distance measure and fast running time make MulRF useful for inferring phylogenies from large collections of gene trees, in which multiple evolutionary processes as well as phylogenetic error may contribute to gene tree discord. MulRF implements several features for customizing the species tree search and assessing the results, and it provides a user-friendly graphical user interface (GUI) with tree visualization. The species tree search is implemented in C++ and the GUI in Java Swing. MulRF's executable as well as sample datasets and manual are available at http://genome.cs.iastate.edu/CBL/MulRF/, and the source code is available at https://github.com/ruchiherself/MulRFRepo. ruchic@ufl.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. The rubber tree genome reveals new insights into rubber production and species adaptation

    OpenAIRE

    Tang, Chaorong; Yang, Meng; Fang, Yongjun; Luo, Yingfeng; Gao, Shenghan; Xiao, Xiaohu; An, Zewei; Zhou, Binhui; Zhang, Bing; Tan, Xinyu; Yeang, Hoong Yeet; Qin, Yunxia; Yang, Jianghua; Lin, Qiang; Mei, Hailiang

    2016-01-01

    The Para rubber tree (Hevea brasiliensis) is an economically important tropical tree species that produces natural rubber, an essential industrial raw material. Here we present a high-quality genome assembly of this species (1.37 Gb, scaffold N50 = 1.28 Mb) that covers 93.8% of the genome (1.47 Gb) and harbours 43,792 predicted protein-coding genes. A striking expansion of the REF/SRPP (rubber elongation factor/small rubber particle protein) gene family and its divergence into several laticif...

  20. Influences of air pollution on the growth of ornamental tree species-particularly with reference to SO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T W

    1975-01-01

    For the purpose of detecting resistance to air pollution, particularly SO/sub 2/ contamination, six ornamental tree species were selected, i.e., Ginkgo biloba, Larix leptolepis, Pinus rigida, Syringa dilatata, Hibiscus syriacus, and Forsythia koreana. The sensitivity was observed and analyzed on the basis of the area ratio of smoke injury spot to the total leaf area. According to the results, the decreasing order of SO/sub 2/ sensitivity by species could be arranged as follows: (1) Hibiscus syriacus, (2) Ginkgo biloba, (3) Forsythia koreana, (4) Syringa dilatata, (5) Larix leptolepis, and (6) Pinus rigida. In general, Hibiscus syriacus and Ginkgo biloba can be grouped as the most resistant ones and Larix leptolepis and Pinus rigida as the weakest ones and Forsythia koreana and Syringa dilatata as the intermediate. Due to the sprouting ability and the formative ability of adventitious buds, the recovery from the SO/sub 2/ fumigation was prominent in Hibiscus syriacus, Syringa dilatata and Forsythia koreana. The differences in the smoke spot color were recognized by species, namely, dirt brown in Syringa dilatata, brilliant yellow brown in Pinus rigida and Ginkgo biloba, whitish yellow in Hibiscus syriacus, and red brown in Forsythia koreana. In the case of Ginkgo biloba and Larix leptolepis, the younger leaves were more resistant to SO/sub 2/ than the old ones. The sulfur content of leaves showed that on the basis of %/dry weight, broad-leaved species contained the higher amount of sulfur than the coniferous species. 15 ornamental tree species which have been growing in Seoul city were sampled from the 19 air polluted spots. The elucidated were the heavily polluted regions and the lightly polluted regions. The SO/sub 2/ absorbing capacities by species are explained in the text. 17 references.

  1. Stochastic modelling of tree architecture and biomass allocation: application to teak (Tectona grandis L. f.), a tree species with polycyclic growth and leaf neoformation.

    Science.gov (United States)

    Tondjo, Kodjo; Brancheriau, Loïc; Sabatier, Sylvie; Kokutse, Adzo Dzifa; Kokou, Kouami; Jaeger, Marc; de Reffye, Philippe; Fourcaud, Thierry

    2018-06-08

    For a given genotype, the observed variability of tree forms results from the stochasticity of meristem functioning and from changing and heterogeneous environmental factors affecting biomass formation and allocation. In response to climate change, trees adapt their architecture by adjusting growth processes such as pre- and neoformation, as well as polycyclic growth. This is the case for the teak tree. The aim of this work was to adapt the plant model, GreenLab, in order to take into consideration both these processes using existing data on this tree species. This work adopted GreenLab formalism based on source-sink relationships at organ level that drive biomass production and partitioning within the whole plant over time. The stochastic aspect of phytomer production can be modelled by a Bernoulli process. The teak model was designed, parameterized and analysed using the architectural data from 2- to 5-year-old teak trees in open field stands. Growth and development parameters were identified, fitting the observed compound organic series with the theoretical series, using generalized least squares methods. Phytomer distributions of growth units and branching pattern varied depending on their axis category, i.e. their physiological age. These emerging properties were in accordance with the observed growth patterns and biomass allocation dynamics during a growing season marked by a short dry season. Annual growth patterns observed on teak, including shoot pre- and neoformation and polycyclism, were reproduced by the new version of the GreenLab model. However, further updating is discussed in order to ensure better consideration of radial variation in basic specific gravity of wood. Such upgrading of the model will enable teak ideotypes to be defined for improving wood production in terms of both volume and quality.

  2. Nutritional composition of five food trees species products used in ...

    African Journals Online (AJOL)

    Nutritional composition of five food trees species products used in human diet during food shortage period in Burkina Faso. Thiombiano Daniabla Natacha Edwige, Parkouda Charles, Lamien Nieyidouba, Sere Aminata, Castro-Euler Ana Margarida, Boussim Issaka Joseph ...

  3. Flavanol binding of nuclei from tree species.

    Science.gov (United States)

    Feucht, W; Treutter, D; Polster, J

    2004-01-01

    Light microscopy was used to examine the nuclei of five tree species with respect to the presence of flavanols. Flavanols develop a blue colouration in the presence of a special p-dimethylaminocinnamaldehyde (DMACA) reagent that enables those nuclei loaded with flavanols to be recognized. Staining of the nuclei was most pronounced in both Tsuga canadensis and Taxus baccata, variable in Metasequoia glyptostroboides, faint in Coffea arabica and minimal in Prunus avium. HPLC analysis showed that the five species contained substantial amounts of different flavanols such as catechin, epicatechin and proanthocyanidins. Quantitatively, total flavanols were quite different among the species. The nuclei themselves, as studied in Tsuga seed wings, were found to contain mainly catechin, much lower amounts of epicatechin and traces of proanthocyanidins. Blue-coloured nuclei located centrally in small cells were often found to maximally occupy up to 90% of a cell's radius, and the surrounding small rim of cytoplasm was visibly free of flavanols. A survey of 34 gymnosperm and angiosperm species indicated that the first group has much higher nuclear binding capacities for flavanols than the second group.

  4. Geography, topography, and history affect realized-to-potential tree species richness patterns in Europe

    DEFF Research Database (Denmark)

    Svenning, J.-C.; Fitzpatrick, Matthew C.; Normand, Signe

    2010-01-01

    by assembly from regional species pools. Using the European tree flora as our study system, we implemented a novel approach to assess the relative importance of local and regional mechanisms that control local species richness. We first identified species pools that tolerate particular local environments....../P richness ratio estimates, but we found consistent support for a negative effect of regional geographic fragmentation and a positive topographic effect. We also identified fairly broad support for the predicted effect of accessibility. We conclude that local tree assemblages in Europe often fail to realize...

  5. Tree species richness, diversity, and regeneration status in different oak (Quercus spp. dominated forests of Garhwal Himalaya, India

    Directory of Open Access Journals (Sweden)

    Sushma Singh

    2016-09-01

    Full Text Available Himalayan forests are dominated by different species of oaks (Quercus spp. at different altitudes. These oaks are intimately linked with hill agriculture as they protect soil fertility, watershed, and local biodiversity. They also play an important role in maintaining ecosystem stability. This work was carried out to study the diversity and regeneration status of some oak forests in Garhwal Himalaya, India. A total of 18 tree species belonging to 16 genera and 12 families were reported from the study area. Species richness varied for trees (4–7, saplings (3–10, and seedlings (2–6. Seedling and sapling densities (Ind/ha varied between 1,376 Ind/ha and 9,600 Ind/ha and 167 Ind/ha and 1,296 Ind/ha, respectively. Species diversity varied from 1.27 to 1.86 (trees, from 0.93 to 3.18 (saplings, and from 0.68 to 2.26 (seedlings. Total basal area (m2/ha of trees and saplings was 2.2–87.07 m2/ha and 0.20–2.24 m2/ha, respectively, whereas that of seedlings varied from 299 cm2/ha to 8,177 cm2/ha. Maximum tree species (20–80% had “good” regeneration. Quercus floribunda, the dominant tree species in the study area, showed “poor” regeneration, which is a matter of concern, and therefore, proper management and conservation strategies need to be developed for maintenance and sustainability of this oak species along with other tree species that show poor or no regeneration.

  6. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

    OpenAIRE

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2015-01-01

    While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal dif...

  7. Growth of 11 introduced tree species on selected forest sites in Hawaii

    Science.gov (United States)

    Michael G Buck; Roger H. Imoto

    1982-01-01

    Growth and volume data for trees on 25 plots reprsenting 11 introduced species in Hawaii were recorded during a 21-year period. Tree were measured at about 5-year intervals to determine overall growth and stand development. The sites selected were considered better-than-average in terms of elevation, amount of precipitation, and soil quality. Except for redwood, stands...

  8. Wind loads and competition for light sculpt trees into self-similar structures.

    Science.gov (United States)

    Eloy, Christophe; Fournier, Meriem; Lacointe, André; Moulia, Bruno

    2017-10-18

    Trees are self-similar structures: their branch lengths and diameters vary allometrically within the tree architecture, with longer and thicker branches near the ground. These tree allometries are often attributed to optimisation of hydraulic sap transport and safety against elastic buckling. Here, we show that these allometries also emerge from a model that includes competition for light, wind biomechanics and no hydraulics. We have developed MECHATREE, a numerical model of trees growing and evolving on a virtual island. With this model, we identify the fittest growth strategy when trees compete for light and allocate their photosynthates to grow seeds, create new branches or reinforce existing ones in response to wind-induced loads. Strikingly, we find that selected trees species are self-similar and follow allometric scalings similar to those observed on dicots and conifers. This result suggests that resistance to wind and competition for light play an essential role in determining tree allometries.

  9. Photosynthetic capacity of tropical montane tree species in relation to leaf nutrients, successional strategy and growth temperature.

    Science.gov (United States)

    Dusenge, Mirindi Eric; Wallin, Göran; Gårdesten, Johanna; Niyonzima, Felix; Adolfsson, Lisa; Nsabimana, Donat; Uddling, Johan

    2015-04-01

    Photosynthetic capacity of tree leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical trees, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the photosynthetic capacity of tropical trees, we collected data on photosynthetic, chemical and morphological leaf traits of ten tree species in Rwanda. Seven species were studied in a forest plantation at mid-altitude (~1,700 m), whereas six species were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three species were common to both sites, and, in the montane rainforest, three pioneer species and three climax species were investigated. Across species, interspecific variation in photosynthetic capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to photosynthetic capacity (higher in pioneer species) versus light-harvesting compounds (higher in climax species). Photosynthetic capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in photosynthetic capacity among tree species in tropical Rwanda, and that (2) tropical montane rainforest species exhibit decreased photosynthetic capacity when grown in a warmer environment.

  10. Limited growth recovery after drought-induced forest dieback in very defoliated trees of two pine species

    Directory of Open Access Journals (Sweden)

    Guillermo eGuada

    2016-04-01

    Full Text Available Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width and intra-annual (xylogenesis scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized three years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die.

  11. Fast growing plantations for wood production – integration of ecological effects and economic perspectives

    Directory of Open Access Journals (Sweden)

    Michael eBredemeier

    2015-06-01

    Full Text Available Biomass crops are perceived as a feasible means to substitute sizeable amounts of fossil fuel in the future. A prospect of CO2 reduction (resp. CO2 neutrality is credited to biomass fuels, and thus a potential contribution to mitigate climate change. Short rotation coppices (SRC with fast growing poplar and willow trees are an option for producing high yields of woody biomass, which is suitable for both energetic and material use. One negative effect that comes along with the establishment of SRC may be a decrease in groundwater recharge, because high rates of transpiration and interception are anticipated. Therefore, it is important to measure, analyse, and model the effects of SRC-planting on landscape water budgets. To analyse the effects on the water budget a poplar SRC plot was studied by measuring hydrological parameters to be used in the hydrological model WaSim. Results reveal very low or even missing ground water recharge for SRC compared to agricultural land use or grassland, especially succeeding dry years. However, this strong effect on plot level is moderated on the larger spatial scale of catchment level, for which the modelling was also performed. In addition to water, nutrient fluxes and budgets were studied. Nitrogen is still a crucial issue in today's agriculture. Intensive fertilization or increased applications of manure from concentrated livestock breeding are often leading to high loads of nitrate leaching, or enhanced N2O emissions to the atmosphere on arable crop fields. SRC or agroforestry systems (AF on former crop land may offer an option to decrease such N losses, while simultaneously producing woody biomass. This is mainly due to the generally smaller N requirements of woody vegetation, which usually entail no need for any fertilization. The trees supply deep and permanent rooting systems, which can be regarded as a safety net to prevent nutrient leaching. Thus, SRC altogether can help to diminish N eutrophication.

  12. Is the extremely rare Iberian endemic plant species Castrilanthemum debeauxii (Compositae, Anthemideae) a 'living fossil'? Evidence from a multi-locus species tree reconstruction.

    Science.gov (United States)

    Tomasello, Salvatore; Álvarez, Inés; Vargas, Pablo; Oberprieler, Christoph

    2015-01-01

    The present study provides results of multi-species coalescent species tree analyses of DNA sequences sampled from multiple nuclear and plastid regions to infer the phylogenetic relationships among the members of the subtribe Leucanthemopsidinae (Compositae, Anthemideae), to which besides the annual Castrilanthemum debeauxii (Degen, Hervier & É.Rev.) Vogt & Oberp., one of the rarest flowering plant species of the Iberian Peninsula, two other unispecific genera (Hymenostemma, Prolongoa), and the polyploidy complex of the genus Leucanthemopsis belong. Based on sequence information from two single- to low-copy nuclear regions (C16, D35, characterised by Chapman et al. (2007)), the multi-copy region of the nrDNA internal transcribed spacer regions ITS1 and ITS2, and two intergenic spacer regions of the cpDNA gene trees were reconstructed using Bayesian inference methods. For the reconstruction of a multi-locus species tree we applied three different methods: (a) analysis of concatenated sequences using Bayesian inference (MrBayes), (b) a tree reconciliation approach by minimizing the number of deep coalescences (PhyloNet), and (c) a coalescent-based species-tree method in a Bayesian framework ((∗)BEAST). All three species tree reconstruction methods unequivocally support the close relationship of the subtribe with the hitherto unclassified genus Phalacrocarpum, the sister-group relationship of Castrilanthemum with the three remaining genera of the subtribe, and the further sister-group relationship of the clade of Hymenostemma+Prolongoa with a monophyletic genus Leucanthemopsis. Dating of the (∗)BEAST phylogeny supports the long-lasting (Early Miocene, 15-22Ma) taxonomical independence and the switch from the plesiomorphic perennial to the apomorphic annual life-form assumed for the Castrilanthemum lineage that may have occurred not earlier than in the Pliocene (3Ma) when the establishment of a Mediterranean climate with summer droughts triggered evolution towards

  13. Use of tree species by White-throated treerunner (Pygarrhichas albogularis King in a secondary native forest of southern Chile

    Directory of Open Access Journals (Sweden)

    Alberto Gantz

    2015-06-01

    Full Text Available ABSTRACT In forest ecosystems, numerous species of insectivorous birds use certain tree species as feeding and nesting substrates. Between 2009 and 2010, the use of different floristic components as feeding substrate by the Pygarrhichas albogularis King, 1831 was evaluated in a southern Chilean secondary native forest. From a total of 13 trees and bush species, six tree species were used by P. albogularis as a feeding substrate. Tree use was limited to intermediate heights (11-20 m and, mainly, to the trunk (40% of observations and secondary branches (26%. Pygarrhichas albogularis showed a disproportionated use of N. dombeyi and an important use of trees with a greater age structure (DBH 81-100 cm. Nothofagus dombeyi presented a significantly greater tree bark crevice depth than E. cordifolia. In turn, covariance between crevice depth and invertebrate supply in tree bark was positive and significant. We consider bark depth and invertebrate supply to be the proximate causes explaining P. albogularis disproportionated use of Nothofagus dombeyi.

  14. Tolerance of Four Tropical Tree Species to Heavy Petroleum Contamination

    NARCIS (Netherlands)

    Perez-Hernandez, I.; Ochoa-Gaona, S.; Schroeder, R.H.A.; Rivera-Cruz, M.C.; Geissen, V.

    2013-01-01

    Four species of trees were selected to evaluate the tolerance to heavy crude oil contamination by means of a tolerance index integrating germination, height, biomass and survival as variables. Fresh seeds to Cedrela odorata (tropical cedar), Haematoxylum campechianum (tinto bush), Swietenia

  15. Inferring species trees from gene trees in a radiation of California trapdoor spiders (Araneae, Antrodiaetidae, Aliatypus.

    Directory of Open Access Journals (Sweden)

    Jordan D Satler

    Full Text Available The California Floristic Province is a biodiversity hotspot, reflecting a complex geologic history, strong selective gradients, and a heterogeneous landscape. These factors have led to high endemic diversity across many lifeforms within this region, including the richest diversity of mygalomorph spiders (tarantulas, trapdoor spiders, and kin in North America. The trapdoor spider genus Aliatypus encompasses twelve described species, eleven of which are endemic to California. Several Aliatypus species show disjunct distributional patterns in California (some are found on both sides of the vast Central Valley, and the genus as a whole occupies an impressive variety of habitats.We collected specimens from 89 populations representing all described species. DNA sequence data were collected from seven gene regions, including two newly developed for spider systematics. Bayesian inference (in individual gene tree and species tree approaches recovered a general "3 clade" structure for the genus (A. gulosus, californicus group, erebus group, with three other phylogenetically isolated species differing slightly in position across different phylogenetic analyses. Because of extremely high intraspecific divergences in mitochondrial COI sequences, the relatively slowly evolving 28S rRNA gene was found to be more useful than mitochondrial data for identification of morphologically indistinguishable immatures. For multiple species spanning the Central Valley, explicit hypothesis testing suggests a lack of monophyly for regional populations (e.g., western Coast Range populations. Phylogenetic evidence clearly shows that syntopy is restricted to distant phylogenetic relatives, consistent with ecological niche conservatism.This study provides fundamental insight into a radiation of trapdoor spiders found in the biodiversity hotspot of California. Species relationships are clarified and undescribed lineages are discovered, with more geographic sampling likely to

  16. Predicting Potential Changes in Suitable Habitat and Distribution by 2100 for Tree Species of the Eastern United States

    Science.gov (United States)

    Louis R Iverson; Anantha M. Prasad; Mark W. Schwartz; Mark W. Schwartz

    2005-01-01

    We predict current distribution and abundance for tree species present in eastern North America, and subsequently estimate potential suitable habitat for those species under a changed climate with 2 x CO2. We used a series of statistical models (i.e., Regression Tree Analysis (RTA), Multivariate Adaptive Regression Splines (MARS), Bagging Trees (...

  17. Species Turnover across Different Life Stages from Seedlings to Canopy Trees in Swamp Forests of Central Brazil

    Directory of Open Access Journals (Sweden)

    Clarissa G. Fontes

    2015-01-01

    Full Text Available Processes driving the assembly of swamp forest communities have been poorly explored. We analyzed natural regeneration and adult tree communities data of a swamp gallery forest in Central Brazil to discuss the role of ecological filters in shaping plant species turnover in a successional gradient. Species data of 120 plots were used to assess species turnover between natural regeneration and adult tree communities. Our analyses were based on 4995 individuals belonging to 72 species. Community patterns were discerned using ordination analyses. A clear floristic turnover among plant life stages was distinguished. Regeneration community of swamp forests was richer in species composition than the adult community. Tree species commonly found in nonflooded gallery forests were present in the regeneration plots but not in the adult community. Differences in the floristic composition of these two strata suggest that not all species in the seedling stage can stand permanent flooding conditions and only a few tolerant species survive to become adult trees. We propose that natural disturbances play an important role by altering limiting resources, allowing seeds of nonflooded forest species to germinate. This paper elucidates the turnover between plant life stages in swamp forests and suggests mechanisms that may shape these communities.

  18. Impacts of short-term heatwaves on sun-induced chlorophyll fluorescence(SiF) in temperate tree species

    Science.gov (United States)

    Wang, F.; Gu, L.; Guha, A.; Han, J.; Warren, J.

    2017-12-01

    The current projections for global climate change forecast an increase in the intensity and frequency of extreme climatic events, such as droughts and short-term heat waves. Understanding the effects of short-term heat wave on photosynthesis process is of critical importance to predict global impacts of extreme weather event on vegetation. The diurnal and seasonal characteristics of SIF emitted from natural vegetation, e.g., forest and crop, have been studied at the ecosystem-scale, regional-scale and global-scale. However, the detailed response of SIF from different plant species under extremely weather event, especially short-term heat wave, have not been reported. The purpose of this study was to study the response of solar-induced chlorophyll fluorescence, gas exchange and continuous fluorescence at leaf scale for different temperate tree species. The short-term heatwave experiment was conducted using plant growth chamber (CMP6050, Conviron Inc., Canada). We developed an advanced spectral fitting method to obtain the plant SIF in the plant growth chamber. We compared SIF variation among different wavelength and chlorophyll difference among four temperate tree species. The diurnal variation of SIF signals at leaf-scales for temperate tree species are different under heat stress. The SIF response at leaf-scales and their difference for four temperate tree species are different during a cycle of short-term heatwave stress. We infer that SIF be used as a measure of heat tolerance for temperate tree species.

  19. Temperature response surfaces for mortality risk of tree species with future drought

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Henry D.; Barron-Gafford, Greg A.; Minor, Rebecca L.; Gardea, Alfonso A.; Bentley, Lisa Patrick; Law, Darin J.; Breshears, David D.; McDowell, Nate G.; Huxman, Travis E.

    2017-11-01

    Widespread, high levels of tree mortality, termed forest die-off, associated with drought and rising temperatures, are disrupting forests worldwide. Drought will likely become more frequent with climate change, but even without more frequent drought, higher temperatures can exacerbate tree water stress. The temperature sensitivity of drought-induced mortality of tree species has been evaluated experimentally for only single-step changes in temperature (ambient compared to ambient + increase) rather than as a response surface (multiple levels of temperature increase), which constrains our ability to relate changes in the driver with the biological response. Here we show that time-to-mortality during drought for seedlings of two western United States tree species, Pinus edulis (Engelm.) and Pinus ponderosa (Douglas ex C. Lawson), declined in continuous proportion with increasing temperature spanning a 7.7 °C increase. Although P. edulis outlived P. ponderosa at all temperatures, both species had similar relative declines in time-to-mortality as temperature increased (5.2% per °C for P. edulis; 5.8% per °C for P. ponderosa). When combined with the non-linear frequency distribution of drought duration—many more short droughts than long droughts—these findings point to a progressive increase in mortality events with global change due to warming alone and independent of additional changes in future drought frequency distributions. As such, dire future forest recruitment patterns are projected assuming the calculated 7-9 seedling mortality events per species by 2100 under business-as-usual warming occurs, congruent with additional vulnerability predicted for adult trees from stressors like pathogens and pests. Our progressive projection for increased mortality events was driven primarily by the non-linear shape of the drought duration frequency distribution, a common climate feature of drought-affected regions. These

  20. Temperature response surfaces for mortality risk of tree species with future drought

    Science.gov (United States)

    Adams, Henry D.; Barron-Gafford, Greg A.; Minor, Rebecca L.; Gardea, Alfonso A.; Bentley, Lisa Patrick; Law, Darin J.; Breshears, David D.; McDowell, Nate G.; Huxman, Travis E.

    2017-11-01

    Widespread, high levels of tree mortality, termed forest die-off, associated with drought and rising temperatures, are disrupting forests worldwide. Drought will likely become more frequent with climate change, but even without more frequent drought, higher temperatures can exacerbate tree water stress. The temperature sensitivity of drought-induced mortality of tree species has been evaluated experimentally for only single-step changes in temperature (ambient compared to ambient + increase) rather than as a response surface (multiple levels of temperature increase), which constrains our ability to relate changes in the driver with the biological response. Here we show that time-to-mortality during drought for seedlings of two western United States tree species, Pinus edulis (Engelm.) and Pinus ponderosa (Douglas ex C. Lawson), declined in continuous proportion with increasing temperature spanning a 7.7 °C increase. Although P. edulis outlived P. ponderosa at all temperatures, both species had similar relative declines in time-to-mortality as temperature increased (5.2% per °C for P. edulis; 5.8% per °C for P. ponderosa). When combined with the non-linear frequency distribution of drought duration—many more short droughts than long droughts—these findings point to a progressive increase in mortality events with global change due to warming alone and independent of additional changes in future drought frequency distributions. As such, dire future forest recruitment patterns are projected assuming the calculated 7-9 seedling mortality events per species by 2100 under business-as-usual warming occur, congruent with additional vulnerability predicted for adult trees from stressors like pathogens and pests. Our progressive projection for increased mortality events was driven primarily by the non-linear shape of the drought duration frequency distribution, a common climate feature of drought-affected regions. These results illustrate profound benefits for

  1. Forest Tree Species Distribution Mapping Using Landsat Satellite Imagery and Topographic Variables with the Maximum Entropy Method in Mongolia

    Science.gov (United States)

    Hao Chiang, Shou; Valdez, Miguel; Chen, Chi-Farn

    2016-06-01

    Forest is a very important ecosystem and natural resource for living things. Based on forest inventories, government is able to make decisions to converse, improve and manage forests in a sustainable way. Field work for forestry investigation is difficult and time consuming, because it needs intensive physical labor and the costs are high, especially surveying in remote mountainous regions. A reliable forest inventory can give us a more accurate and timely information to develop new and efficient approaches of forest management. The remote sensing technology has been recently used for forest investigation at a large scale. To produce an informative forest inventory, forest attributes, including tree species are unavoidably required to be considered. In this study the aim is to classify forest tree species in Erdenebulgan County, Huwsgul province in Mongolia, using Maximum Entropy method. The study area is covered by a dense forest which is almost 70% of total territorial extension of Erdenebulgan County and is located in a high mountain region in northern Mongolia. For this study, Landsat satellite imagery and a Digital Elevation Model (DEM) were acquired to perform tree species mapping. The forest tree species inventory map was collected from the Forest Division of the Mongolian Ministry of Nature and Environment as training data and also used as ground truth to perform the accuracy assessment of the tree species classification. Landsat images and DEM were processed for maximum entropy modeling, and this study applied the model with two experiments. The first one is to use Landsat surface reflectance for tree species classification; and the second experiment incorporates terrain variables in addition to the Landsat surface reflectance to perform the tree species classification. All experimental results were compared with the tree species inventory to assess the classification accuracy. Results show that the second one which uses Landsat surface reflectance coupled

  2. FOREST TREE SPECIES DISTRIBUTION MAPPING USING LANDSAT SATELLITE IMAGERY AND TOPOGRAPHIC VARIABLES WITH THE MAXIMUM ENTROPY METHOD IN MONGOLIA

    Directory of Open Access Journals (Sweden)

    S. H. Chiang

    2016-06-01

    Full Text Available Forest is a very important ecosystem and natural resource for living things. Based on forest inventories, government is able to make decisions to converse, improve and manage forests in a sustainable way. Field work for forestry investigation is difficult and time consuming, because it needs intensive physical labor and the costs are high, especially surveying in remote mountainous regions. A reliable forest inventory can give us a more accurate and timely information to develop new and efficient approaches of forest management. The remote sensing technology has been recently used for forest investigation at a large scale. To produce an informative forest inventory, forest attributes, including tree species are unavoidably required to be considered. In this study the aim is to classify forest tree species in Erdenebulgan County, Huwsgul province in Mongolia, using Maximum Entropy method. The study area is covered by a dense forest which is almost 70% of total territorial extension of Erdenebulgan County and is located in a high mountain region in northern Mongolia. For this study, Landsat satellite imagery and a Digital Elevation Model (DEM were acquired to perform tree species mapping. The forest tree species inventory map was collected from the Forest Division of the Mongolian Ministry of Nature and Environment as training data and also used as ground truth to perform the accuracy assessment of the tree species classification. Landsat images and DEM were processed for maximum entropy modeling, and this study applied the model with two experiments. The first one is to use Landsat surface reflectance for tree species classification; and the second experiment incorporates terrain variables in addition to the Landsat surface reflectance to perform the tree species classification. All experimental results were compared with the tree species inventory to assess the classification accuracy. Results show that the second one which uses Landsat surface

  3. Project CAPTURE: a U.S. national prioritization assessment of tree species for conservation, management, and restoration

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane; Valerie D. Hipkins

    2017-01-01

    that forest tree species will undergo population-level extirpation or species-level extinction during the next century. Project CAPTURE (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) is a cooperative effort across the three U.S. Department of Agriculture Forest Service (USDA FS) deputy areas to establish a framework for...

  4. Tree species mapping in tropical forests using multi-temporal imaging spectroscopy: Wavelength adaptive spectral mixture analysis

    Science.gov (United States)

    Somers, B.; Asner, G. P.

    2014-09-01

    The use of imaging spectroscopy for florisic mapping of forests is complicated by the spectral similarity among co-existing species. Here we evaluated an alternative spectral unmixing strategy combining a time series of EO-1 Hyperion images and an automated feature selection in Multiple Endmember Spectral Mixture Analysis (MESMA). The temporal analysis provided a way to incorporate species phenology while feature selection indicated the best phenological time and best spectral feature set to optimize the separability between tree species. Instead of using the same set of spectral bands throughout the image which is the standard approach in MESMA, our modified Wavelength Adaptive Spectral Mixture Analysis (WASMA) approach allowed the spectral subsets to vary on a per pixel basis. As such we were able to optimize the spectral separability between the tree species present in each pixel. The potential of the new approach for floristic mapping of tree species in Hawaiian rainforests was quantitatively assessed using both simulated and actual hyperspectral image time-series. With a Cohen's Kappa coefficient of 0.65, WASMA provided a more accurate tree species map compared to conventional MESMA (Kappa = 0.54; p-value < 0.05. The flexible or adaptive use of band sets in WASMA provides an interesting avenue to address spectral similarities in complex vegetation canopies.

  5. Multi-phenology WorldView-2 imagery improves remote sensing of savannah tree species

    Science.gov (United States)

    Madonsela, Sabelo; Cho, Moses Azong; Mathieu, Renaud; Mutanga, Onisimo; Ramoelo, Abel; Kaszta, Żaneta; Kerchove, Ruben Van De; Wolff, Eléonore

    2017-06-01

    Biodiversity mapping in African savannah is important for monitoring changes and ensuring sustainable use of ecosystem resources. Biodiversity mapping can benefit from multi-spectral instruments such as WorldView-2 with very high spatial resolution and a spectral configuration encompassing important spectral regions not previously available for vegetation mapping. This study investigated i) the benefits of the eight-band WorldView-2 (WV-2) spectral configuration for discriminating tree species in Southern African savannah and ii) if multiple-images acquired at key points of the typical phenological development of savannahs (peak productivity, transition to senescence) improve on tree species classifications. We first assessed the discriminatory power of WV-2 bands using interspecies-Spectral Angle Mapper (SAM) via Band Add-On procedure and tested the spectral capability of WorldView-2 against simulated IKONOS for tree species classification. The results from interspecies-SAM procedure identified the yellow and red bands as the most statistically significant bands (p = 0.000251 and p = 0.000039 respectively) in the discriminatory power of WV-2 during the transition from wet to dry season (April). Using Random Forest classifier, the classification scenarios investigated showed that i) the 8-bands of the WV-2 sensor achieved higher classification accuracy for the April date (transition from wet to dry season, senescence) compared to the March date (peak productivity season) ii) the WV-2 spectral configuration systematically outperformed the IKONOS sensor spectral configuration and iii) the multi-temporal approach (March and April combined) improved the discrimination of tress species and produced the highest overall accuracy results at 80.4%. Consistent with the interspecies-SAM procedure, the yellow (605 nm) band also showed a statistically significant contribution in the improved classification accuracy from WV-2. These results highlight the mapping opportunities

  6. Current and Future Distribution of the Tropical Tree Cedrela odorata L. in Mexico under Climate Change Scenarios Using MaxLike

    Science.gov (United States)

    Martínez Meyer, Enrique; Sánchez-Velásquez, Lázaro R.

    2016-01-01

    Climate change is recognized as an important threat to global biodiversity because it increases the risk of extinction of many species on the planet. Mexico is a megadiverse country and native tree species such as red cedar (Cedrela odorata) can be used to maintain forests while helping mitigate climate change, because it is considered a fast growing pioneer species with great economic potential in the forestry industry. In order to assess possible shifts in areas suitable for C. odorata plantations in Mexico with ecological niche models, we used the MaxLike algorithm, climate variables, the geo-referenced records of this species, three general circulation models and three scenarios of future emissions. Results show a current potential distribution of 573,079 km2 with an average probability of occurrence of 0.93 (± 0.13). The potential distribution area could increase up to 650,356 km2 by 2060 according to the general circulation model HADCM3 B2, with an average probability of occurrence of 0.86 (± 0.14). Finally, we delimited an area of 35,377 km2 that has a high potential for the establishment of C. odorata plantations, by selecting those sites with optimal conditions for its growth that are outside protected areas and are currently devoid of trees. C. odorata has a significant potential to help in the mitigation of the effects of climate change. Using MaxLike we identified extense areas in Mexico suitable to increase carbon sequestration through plantations of this highly valued native tree species. PMID:27732622

  7. Current and Future Distribution of the Tropical Tree Cedrela odorata L. in Mexico under Climate Change Scenarios Using MaxLike.

    Science.gov (United States)

    Estrada-Contreras, Israel; Equihua, Miguel; Laborde, Javier; Martínez Meyer, Enrique; Sánchez-Velásquez, Lázaro R

    2016-01-01

    Climate change is recognized as an important threat to global biodiversity because it increases the risk of extinction of many species on the planet. Mexico is a megadiverse country and native tree species such as red cedar (Cedrela odorata) can be used to maintain forests while helping mitigate climate change, because it is considered a fast growing pioneer species with great economic potential in the forestry industry. In order to assess possible shifts in areas suitable for C. odorata plantations in Mexico with ecological niche models, we used the MaxLike algorithm, climate variables, the geo-referenced records of this species, three general circulation models and three scenarios of future emissions. Results show a current potential distribution of 573,079 km2 with an average probability of occurrence of 0.93 (± 0.13). The potential distribution area could increase up to 650,356 km2 by 2060 according to the general circulation model HADCM3 B2, with an average probability of occurrence of 0.86 (± 0.14). Finally, we delimited an area of 35,377 km2 that has a high potential for the establishment of C. odorata plantations, by selecting those sites with optimal conditions for its growth that are outside protected areas and are currently devoid of trees. C. odorata has a significant potential to help in the mitigation of the effects of climate change. Using MaxLike we identified extense areas in Mexico suitable to increase carbon sequestration through plantations of this highly valued native tree species.

  8. Current and Future Distribution of the Tropical Tree Cedrela odorata L. in Mexico under Climate Change Scenarios Using MaxLike.

    Directory of Open Access Journals (Sweden)

    Israel Estrada-Contreras

    Full Text Available Climate change is recognized as an important threat to global biodiversity because it increases the risk of extinction of many species on the planet. Mexico is a megadiverse country and native tree species such as red cedar (Cedrela odorata can be used to maintain forests while helping mitigate climate change, because it is considered a fast growing pioneer species with great economic potential in the forestry industry. In order to assess possible shifts in areas suitable for C. odorata plantations in Mexico with ecological niche models, we used the MaxLike algorithm, climate variables, the geo-referenced records of this species, three general circulation models and three scenarios of future emissions. Results show a current potential distribution of 573,079 km2 with an average probability of occurrence of 0.93 (± 0.13. The potential distribution area could increase up to 650,356 km2 by 2060 according to the general circulation model HADCM3 B2, with an average probability of occurrence of 0.86 (± 0.14. Finally, we delimited an area of 35,377 km2 that has a high potential for the establishment of C. odorata plantations, by selecting those sites with optimal conditions for its growth that are outside protected areas and are currently devoid of trees. C. odorata has a significant potential to help in the mitigation of the effects of climate change. Using MaxLike we identified extense areas in Mexico suitable to increase carbon sequestration through plantations of this highly valued native tree species.

  9. Stem CO2 efflux in six co-occurring tree species: underlying factors and ecological implications.

    Science.gov (United States)

    Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis

    2015-06-01

    Stem respiration plays a role in species coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed trees of six deciduous species in a mixed forest stand: Fagus sylvatica L., Quercus petraea [Matt.] Liebl, Quercus pyrenaica Willd., Prunus avium L., Sorbus aucuparia L. and Crataegus monogyna Jacq. We conducted measurements in late autumn. Within species, dominants had higher E per unit stem surface area (Es ) mainly because sapwood depth was higher than in suppressed trees. Across species, however, differences in Es corresponded with differences in the proportion of living parenchyma in sapwood and concentration of non-structural carbohydrates (NSC). Across species, Es was strongly and NSC marginally positively related with an index of drought tolerance, suggesting that slow growth of drought-tolerant trees is related to higher NSC concentration and Es . We conclude that, during the leafless period, E is indicative of maintenance respiration and is related with some ecological characteristics of the species, such as drought resistance; that sapwood depth is the main factor explaining variability in Es within species; and that the proportion of NSC in the sapwood is the main factor behind variability in Es among species. © 2014 John Wiley & Sons Ltd.

  10. Seedling growth strategies in Bauhinia species: comparing lianas and trees

    NARCIS (Netherlands)

    Cai, Z.Q.; Poorter, L.; Cao, K.F.; Bongers, F.J.J.M.

    2007-01-01

    Background and Aims: Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass

  11. Regional variation in Caribbean dry forest tree species composition

    Science.gov (United States)

    Janet Franklin; Julie Ripplinger; Ethan H. Freid; Humfredo Marcano-Vega; David W. Steadman

    2015-01-01

    How does tree species composition vary in relation to geographical and environmental gradients in a globally rare tropical/subtropical broadleaf dry forest community in the Caribbean? We analyzed data from 153 Forest Inventory and Analysis (FIA) plots from Puerto Rico and the U.S. Virgin Islands (USVI), along with 42 plots that we sampled in the Bahamian Archipelago (...

  12. Environmental and biological controls of urban tree transpiration in the Upper Midwest

    Science.gov (United States)

    Peters, E. B.; McFadden, J.; Montgomery, R.

    2009-12-01

    Urban trees provide a variety of ecosystem services to urban and suburban areas, including carbon uptake, climate amelioration, energy reduction, and stormwater management. Tree transpiration, in particular, modifies urban water budgets by providing an alternative pathway for water after rain events. The relative importance of environmental and biological controls on transpiration are poorly understood in urban areas, yet these controls are important for quantifying and scaling up the ecosystem services that urban trees provide at landscape and regional scales and predicting how urban ecosystems will respond to climate changes. The objectives of our study were to quantify the annual cycle of tree transpiration in an urban ecosystem and to determine how different urban tree species and plant functional types respond to environmental drivers. We continuously measured whole-tree transpiration using thermal dissipation sap flow at four urban forest stands that were broadly representative of the species composition and tree sizes found in a suburban residential neighborhood of Minneapolis-Saint Paul, Minnesota. A total of 40 trees, representing different species, plant functional types, successional stages, and xylem anatomy, were sampled throughout the 2007 and 2008 growing seasons (April-November). At each site we monitored soil moisture, air temperature, and relative humidity continuously, and we measured leaf area index weekly. Urban tree transpiration was strongly correlated with diurnal changes in vapor pressure deficit and photosynthetically active radiation and with seasonal changes in leaf area index. We found that plant functional type better explained species differences in transpiration per canopy area than either successional stage or xylem anatomy, largely due to differences in canopy structure between conifer and broad-leaf deciduous trees. We also observed inter-annual differences in transpiration rates due to a mid-season drought and longer growing

  13. Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests

    DEFF Research Database (Denmark)

    Augusto, Laurent; De Schrijver, An; Vesterdal, Lars

    2015-01-01

    It has been recognized for a long time that the overstorey composition of a forest partly determines its biological and physical-chemical functioning. Here, we review evidence of the influence of evergreen gymnosperm (EG) tree species and deciduous angiosperm (DA) tree species on the water balance...... present the current state of the art, define knowledge gaps, and briefly discuss how selection of tree species can be used to mitigate pollution or enhance accumulation of stable organic carbon in the soil. The presence of EGs generally induces a lower rate of precipitation input into the soil than DAs......, resulting in drier soil conditions and lower water discharge. Soil temperature is generally not different, or slightly lower, under an EG canopy compared to a DA canopy. Chemical properties, such as soil pH, can also be significantly modified by taxonomic groups of tree species. Biomass production...

  14. Exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions

    International Nuclear Information System (INIS)

    Nunn, Angela J.; Wieser, Gerhard; Metzger, Ursula; Loew, Markus; Wipfler, Philip; Haeberle, Karl-Heinz; Matyssek, Rainer

    2007-01-01

    Whole-tree O 3 uptake was exemplified for Picea abies, Fagus sylvatica and Larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on O 3 flux. O 3 uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. The responsiveness of the canopy conductance to water vapor and, as a consequence, O 3 uptake to soil moisture and air humidity did not differ between species. Unifying findings at the whole-tree level will promote cause-effect based O 3 risk assessment and modeling. - Sap flow-based assessment of whole-tree O 3 uptake reflects similar responsiveness of canopy conductance and O 3 uptake across contrasting tree species and site conditions

  15. Participatory Selection of Tree Species for Agroforestry on Sloping Land in North Korea

    Directory of Open Access Journals (Sweden)

    Jun He

    2015-11-01

    Full Text Available The action research project reported in this article used a participatory approach to select trees for sloping-land agroforestry as a key strategy for forest ecosystem restoration and local livelihood development. It was the first such project in the Democratic People’s Republic of Korea (North Korea to use a participatory approach, empowering local user groups to develop their preferences for agroforestry species. Local knowledge of the multiple functions of agroforestry species ensured that the tree selection criteria included the value of timber, fruit, fodder, oil, medicines, fuelwood, and erosion control. Involving 67 farmers from 3 counties, this participatory selection process resulted in Prunus armeniaca, Castanea crenata, and Ziziphus jujuba being selected as the top 3 species for the development of sloping-land agroforestry in North Hwanghae Province. These trees embody what the region’s farmers value most: erosion control, production of fruit, and economic value. The participatory approach in agroforestry could help to meet both local needs for food security and the national objective of environmental conservation and has great potential for wide adaptation in North Korea and beyond.

  16. composition and size class structure of tree species in ihang'ana

    African Journals Online (AJOL)

    nb

    Previous plant biodiversity studies in this ecosystem concentrated on large-sized Forest ... assess tree species composition, structure and diversity in Ihang'ana FR (2982 ha), one of the ..... Dombeya rotundifolia. (Hochst) ... Ficus lutea. Vahl.

  17. Geography, topography, and history affect realized-to-potential tree species richness patterns in Europe

    Science.gov (United States)

    Jens-Christian Svenning; Matthew C. Fitzpatrick; Signe Normand; Catherine H. Graham; Peter B. Pearman; Louis R. Iverson; Flemming. Skov

    2010-01-01

    Environmental conditions and biotic interactions are generally thought to influence local species richness. However, immigration and the evolutionary and historical factors that shape regional species pools should also contribute to determining local species richness because local communities arise by assembly from regional species pools. Using the European tree flora...

  18. Spectral mapping of savanna tree species at canopy level, with focus on tall trees, using an integrated CAO Hyperspectral & LiDAR sensor approach

    CSIR Research Space (South Africa)

    Naidoo, L

    2010-03-01

    Full Text Available The detection and mapping of tree/plant species in the savanna ecosystem can provide numerous benefits for the managerial authorities. This includes the accurate mapping of the spatial distribution of economically viable trees which are a key source...

  19. No evidence that boron influences tree species distributions in lowland tropical forests of Panama.

    Science.gov (United States)

    Turner, Benjamin L; Zalamea, Paul-Camilo; Condit, Richard; Winter, Klaus; Wright, S Joseph; Dalling, James W

    2017-04-01

    It was recently proposed that boron might be the most important nutrient structuring tree species distributions in tropical forests. Here we combine observational and experimental studies to test this hypothesis for lowland tropical forests of Panama. Plant-available boron is uniformly low in tropical forest soils of Panama and is not significantly associated with any of the > 500 species in a regional network of forest dynamics plots. Experimental manipulation of boron supply to seedlings of three tropical tree species revealed no evidence of boron deficiency or toxicity at concentrations likely to occur in tropical forest soils. Foliar boron did not correlate with soil boron along a local scale gradient of boron availability. Fifteen years of boron addition to a tropical forest increased plant-available boron by 70% but did not significantly change tree productivity or boron concentrations in live leaves, wood or leaf litter. The annual input of boron in rainfall accounts for a considerable proportion of the boron in annual litterfall and is similar to the pool of plant-available boron in the soil, and is therefore sufficient to preclude boron deficiency. We conclude that boron does not influence tree species distributions in Panama and presumably elsewhere in the lowland tropics. No claim to original US government works New Phytologist © 2016 New Phytologist Trust.

  20. Thermal tolerance, net CO2 exchange and growth of a tropical tree species, Ficus insipida, cultivated at elevated daytime and nighttime temperatures.

    Science.gov (United States)

    Krause, G Heinrich; Cheesman, Alexander W; Winter, Klaus; Krause, Barbara; Virgo, Aurelio

    2013-06-15

    Global warming and associated increases in the frequency and amplitude of extreme weather events, such as heat waves, may adversely affect tropical rainforest plants via significantly increased tissue temperatures. In this study, the response to two temperature regimes was assessed in seedlings of the neotropical pioneer tree species, Ficus insipida. Plants were cultivated in growth chambers at strongly elevated daytime temperature (39°C), combined with either close to natural (22°C) or elevated (32°C) nighttime temperatures. Under both growth regimes, the critical temperature for irreversible leaf damage, determined by changes in chlorophyll a fluorescence, was approximately 51°C. This is comparable to values found in F. insipida growing under natural ambient conditions and indicates a limited potential for heat tolerance acclimation of this tropical forest tree species. Yet, under high nighttime temperature, growth was strongly enhanced, accompanied by increased rates of net photosynthetic CO2 uptake and diminished temperature dependence of leaf-level dark respiration, consistent with thermal acclimation of these key physiological parameters. Copyright © 2013 Elsevier GmbH. All rights reserved.

  1. [Biomass allometric equations of nine common tree species in an evergreen broadleaved forest of subtropical China].

    Science.gov (United States)

    Zuo, Shu-di; Ren, Yin; Weng, Xian; Ding, Hong-feng; Luo, Yun-jian

    2015-02-01

    Biomass allometric equation (BAE) considered as a simple and reliable method in the estimation of forest biomass and carbon was used widely. In China, numerous studies focused on the BAEs for coniferous forest and pure broadleaved forest, and generalized BAEs were frequently used to estimate the biomass and carbon of mixed broadleaved forest, although they could induce large uncertainty in the estimates. In this study, we developed the species-specific and generalized BAEs using biomass measurement for 9 common broadleaved trees (Castanopsis fargesii, C. lamontii, C. tibetana, Lithocarpus glaber, Sloanea sinensis, Daphniphyllum oldhami, Alniphyllum fortunei, Manglietia yuyuanensis, and Engelhardtia fenzlii) of subtropical evergreen broadleaved forest, and compared differences in species-specific and generalized BAEs. The results showed that D (diameter at breast height) was a better independent variable in estimating the biomass of branch, leaf, root, aboveground section and total tree than a combined variable (D2 H) of D and H (tree height) , but D2H was better than D in estimating stem biomass. R2 (coefficient of determination) values of BAEs for 6 species decreased when adding H as the second independent variable into D- only BAEs, where R2 value for S. sinensis decreased by 5.6%. Compared with generalized D- and D2H-based BAEs, standard errors of estimate (SEE) of BAEs for 8 tree species decreased, and similar decreasing trend was observed for different components, where SEEs of the branch decreased by 13.0% and 20.3%. Therefore, the biomass carbon storage and its dynamic estimates were influenced largely by tree species and model types. In order to improve the accuracy of the estimates of biomass and carbon, we should consider the differences in tree species and model types.

  2. Tree species traits cause divergence in soil acidification during four decades of postagricultural forest development

    DEFF Research Database (Denmark)

    Schrijver, An de; Frenne, Pieter de; Staelens, Jeroen

    2012-01-01

    -depth understanding of tree species-specific effects on soil acidification is therefore crucial, particularly in view of the predicted global increases in acidifying nitrogen (N) deposition. Here, we report soil acidification rates in a chronosequence of broadleaved deciduous forests planted on former arable land...... and unequivocally drives postagricultural forests towards more acidic conditions, but the rate of soil acidification is also determined by the tree species-specific leaf litter quality and litter decomposition rates. We propose that the intrinsic differences in leaf litter quality among tree species create...... fundamentally different nutrient cycles within the ecosystem, both directly through the chemical composition of the litter and indirectly through its effects on the size and composition of earthworm communities. Poor leaf litter quality contributes to the absence of a burrowing earthworm community, which...

  3. Thermal analysis of wood of the main tree species of Central Siberia

    Directory of Open Access Journals (Sweden)

    S. R. Loskutov

    2015-12-01

    Full Text Available Thermal decomposition of wood from coniferous and deciduous species of Siberia has been studied using thermogravimetry (TG and differential scanning calorimetry (DSC. The tree species were larch Larix sibirica Ledeb., Scots pine Pinus sylvestris L., spruce Picea obovata Ledeb., fir Abies sibirica Ledeb., Siberian pine Pinus sibirica Du Tour., birch Betula pendula Roth., and aspen Populus tremula L. Thermal analysis of wood samples was carried out under oxidative (air and inert (argon atmospheres from 25 to 700 °С at heating rates 10, 20, 40 °С • min–1 (TG/DTG and from 25 to 590 °С at heating rates 10, 40 °С • min–1 (DSC. The stages of thermal decomposition, the temperature intervals, the mass loss, the mass loss rate, the temperature of DTG/DSC peaks, and heating effects were determined for each tree species. The kinetic thermal degradation parameters of wood were obtained by the Broido and Ozawa–Flynn–Wall models. The wood of coniferous and deciduous species of Siberia was characterized on the base of analysis of activation energy values at various stages of thermal decomposition and the relations of activation energy on conversion level of wood substance of different tree species, and also the comparison of mass loss at the same stages of thermal destruction, heating effects, residual mass and other parameters of TG/DTG, DSC. In our opinion, the results of this work present interest for researchers and specialists in the field of forest pyrology, wood science, dendrochemistry.

  4. Spatial distribution and interspecific associations of tree species in a tropical seasonal rain forest of China.

    Directory of Open Access Journals (Sweden)

    Guoyu Lan

    Full Text Available Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1 fourteen of the twenty tree species were negatively (or positively associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2 Most saplings of the study species showed a significantly clumped distribution at small scales (0-10 m which was lost at larger scales (10-30 m. (3 The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4 It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China.

  5. Species-Level Para- and Polyphyly in DNA Barcode Gene Trees: Strong Operational Bias in European Lepidoptera.

    Science.gov (United States)

    Mutanen, Marko; Kivelä, Sami M; Vos, Rutger A; Doorenweerd, Camiel; Ratnasingham, Sujeevan; Hausmann, Axel; Huemer, Peter; Dincă, Vlad; van Nieukerken, Erik J; Lopez-Vaamonde, Carlos; Vila, Roger; Aarvik, Leif; Decaëns, Thibaud; Efetov, Konstantin A; Hebert, Paul D N; Johnsen, Arild; Karsholt, Ole; Pentinsaari, Mikko; Rougerie, Rodolphe; Segerer, Andreas; Tarmann, Gerhard; Zahiri, Reza; Godfray, H Charles J

    2016-11-01

    The proliferation of DNA data is revolutionizing all fields of systematic research. DNA barcode sequences, now available for millions of specimens and several hundred thousand species, are increasingly used in algorithmic species delimitations. This is complicated by occasional incongruences between species and gene genealogies, as indicated by situations where conspecific individuals do not form a monophyletic cluster in a gene tree. In two previous reviews, non-monophyly has been reported as being common in mitochondrial DNA gene trees. We developed a novel web service "Monophylizer" to detect non-monophyly in phylogenetic trees and used it to ascertain the incidence of species non-monophyly in COI (a.k.a. cox1) barcode sequence data from 4977 species and 41,583 specimens of European Lepidoptera, the largest data set of DNA barcodes analyzed from this regard. Particular attention was paid to accurate species identification to ensure data integrity. We investigated the effects of tree-building method, sampling effort, and other methodological issues, all of which can influence estimates of non-monophyly. We found a 12% incidence of non-monophyly, a value significantly lower than that observed in previous studies. Neighbor joining (NJ) and maximum likelihood (ML) methods yielded almost equal numbers of non-monophyletic species, but 24.1% of these cases of non-monophyly were only found by one of these methods. Non-monophyletic species tend to show either low genetic distances to their nearest neighbors or exceptionally high levels of intraspecific variability. Cases of polyphyly in COI trees arising as a result of deep intraspecific divergence are negligible, as the detected cases reflected misidentifications or methodological errors. Taking into consideration variation in sampling effort, we estimate that the true incidence of non-monophyly is ∼23%, but with operational factors still being included. Within the operational factors, we separately assessed the

  6. Tree host range and world distribution of the extomycorrhizal fungus Pisolithus tinctorius.

    Science.gov (United States)

    Marx, D H

    1977-03-01

    The natural occurrence of Pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the United States. This ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. Experiments have proved that this fungal symbiont forms ectomycorrhizae with Abies procera, Betula pendula, Carya illnoensis, 11 species of Eucalyptus, 30 species of Pinus, Pseudotsuga menziesii var. meniziesii, 2 species of Quercus, and Tsuga heterophylla. Pisolithus has also been reported growing under natural conditions in association with three additional species of Betula, two species of Eucalyptus, nine species of Pinus, and eight species of Quercus, Populus tremuloides, Pseudotsuga grandidenta, and Salix humilis. This fungal symbiont has great potential in forestation efforts because of (1) the availability of practical techniques for artificially introducing in into nursery soils; (2) its ability to improve tree survival and growth in the nursery and the field; (3) its near worldwide distribution on a variety of sites; and (4) its broad host range encompassing many of the world's most important tree species.

  7. Variability in urban soils influences the health and growth of native tree seedlings

    Science.gov (United States)

    Clara C. Pregitzer; Nancy F. Sonti; Richard A. Hallett

    2016-01-01

    Reforesting degraded urban landscapes is important due to the many benefits urban forests provide. Urban soils are highly variable, yet little is known about how this variability in urban soils influences tree seedling performance and survival. We conducted a greenhouse study to assess health, growth, and survival of four native tree species growing in native glacial...

  8. TREE SPECIES CLASSIFICATION OF BROADLEAVED FORESTS IN NAGANO, CENTRAL JAPAN, USING AIRBORNE LASER DATA AND MULTISPECTRAL IMAGES

    Directory of Open Access Journals (Sweden)

    S. Deng

    2017-10-01

    Full Text Available This study attempted to classify three coniferous and ten broadleaved tree species by combining airborne laser scanning (ALS data and multispectral images. The study area, located in Nagano, central Japan, is within the broadleaved forests of the Afan Woodland area. A total of 235 trees were surveyed in 2016, and we recorded the species, DBH, and tree height. The geographical position of each tree was collected using a Global Navigation Satellite System (GNSS device. Tree crowns were manually detected using GNSS position data, field photographs, true-color orthoimages with three bands (red-green-blue, RGB, 3D point clouds, and a canopy height model derived from ALS data. Then a total of 69 features, including 27 image-based and 42 point-based features, were extracted from the RGB images and the ALS data to classify tree species. Finally, the detected tree crowns were classified into two classes for the first level (coniferous and broadleaved trees, four classes for the second level (Pinus densiflora, Larix kaempferi, Cryptomeria japonica, and broadleaved trees, and 13 classes for the third level (three coniferous and ten broadleaved species, using the 27 image-based features, 42 point-based features, all 69 features, and the best combination of features identified using a neighborhood component analysis algorithm, respectively. The overall classification accuracies reached 90 % at the first and second levels but less than 60 % at the third level. The classifications using the best combinations of features had higher accuracies than those using the image-based and point-based features and the combination of all of the 69 features.

  9. Management of Animal Carcass Disposal Sites Using a Biochar Permeable Reactive Barrier and Fast Growth Tree (Populus euramericana: A Field Study in Korea

    Directory of Open Access Journals (Sweden)

    Jung-Hwan Yoon

    2017-03-01

    Full Text Available Among many disposal options of animal carcasses due to animal diseases including foot-and-mouth disease (FMD and avian influenza (AI, on-farm burial has been the most frequently used one in Korea. Animal carcasses generate contaminants such as ammonium-N and chloride. This study aimed at testing biochar (BC as a permeable reactive barrier (PRB material in combination with fast growing tree species (Populus euramericana to mitigate groundwater pollution from animal burial sites. For this, a PRB filled with BC was installed and 400 poplar tree (P. euramericana seedlings were planted. Tested BC was obtained from rice husk and its efficiency to mitigate contaminant migration from a burial site of pig carcasses was tested using ammonium-N, chloride, electrical conductivity (EC, and pH as monitoring parameters. Monitoring wells downstream from the burial site were used. Leachates from a monitoring well, three wells inside the burial site close to PRB and three wells outside the burial site close to PRB were sampled and analyzed for ammonium-N, Cl−, EC, and pH for four years from PRB installation. The pH, EC, and ammonium-N of leachate fluctuated during the test period depending on precipitation. pH, EC, and ammonium-N of the leachate samples collected from outside of the burial site close to PRB decreased compared to those from inside of the burial site close to PRB. The concentrations of ammonium-N in the leachate from the monitoring well kept under the threshold value of 10 mg·L−1 for two years from PRB construction. In addition, the growth of poplar plants appeared to be increased via uptaking available N and P released from the burial sites. Achieved results suggest that BC PRBs can be used to in situ mitigate contaminant release from buried animal carcasses.

  10. Gas exchange, heat production and oxidation of fat in chicken embryos from a fast or slow growing line

    DEFF Research Database (Denmark)

    Chwalibog, André; Tauson, Anne-Helene; Ali, Abdalla

    2007-01-01

    The experiment comprised 48 chicken (Gallus gallus) embryos from a modern, fast growing line, Ross 308 (RO) and 48 from a slow growing line, Labresse (LA). The O(2) consumption and CO(2) production were measured in an open-air-circuit respiration unit, and heat production (HE) from embryos was ca...

  11. Summer droughts limit tree growth across 10 temperate species on a productive forest site

    NARCIS (Netherlands)

    Weemstra, M.; Eilmann, B.; Sass-Klaassen, U.; Sterck, F.J.

    2013-01-01

    Studies on climate impacts on tree annual growth are mainly restricted to marginal sites. To date, the climate effects on annual growth of trees in favorable environments remain therefore unclear despite the importance of these sites in terms of forest productivity. Because species respond

  12. Tree mortality in response to typhoon-induced floods and mudslides is determined by tree species, size, and position in a riparian Formosan gum forest in subtropical Taiwan

    Science.gov (United States)

    Tzeng, Hsy-Yu; Wang, Wei; Tseng, Yen-Hsueh; Chiu, Ching-An; Kuo, Chu-Chia

    2018-01-01

    Global warming-induced extreme climatic changes have increased the frequency of severe typhoons bringing heavy rains; this has considerably affected the stability of the forest ecosystems. Since the Taiwan 921 earthquake occurred in 21 September 1999, the mountain geology of the Island of Taiwan has become unstable and typhoon-induced floods and mudslides have changed the topography and geomorphology of the area; this has further affected the stability and functions of the riparian ecosystem. In this study, the vegetation of the unique Aowanda Formosan gum forest in Central Taiwan was monitored for 3 years after the occurrence of floods and mudslides during 2009–2011. Tree growth and survival, effects of floods and mudslides, and factors influencing tree survival were investigated. We hypothesized that (1) the effects of floods on the survival are significantly different for each tree species; (2) tree diameter at breast height (DBH) affects tree survival–i.e., the larger the DBH, the higher the survival rate; and (3) the relative position of trees affects tree survival after disturbances by floods and mudslides–the farther trees are from the river, the higher is their survival rate. Our results showed that after floods and mudslides, the lifespans of the major tree species varied significantly. Liquidambar formosana displayed the highest flood tolerance, and the trunks of Lagerstoemia subcostata began rooting after disturbances. Multiple regression analysis indicated that factors such as species, DBH, distance from sampled tree to the above boundary of sample plot (far from the riverbank), and distance from the upstream of the river affected the lifespans of trees; the three factors affected each tree species to different degrees. Furthermore, we showed that insect infestation had a critical role in determining tree survival rate. Our 3-year monitoring investigation revealed that severe typhoon-induced floods and mudslides disturbed the riparian vegetation

  13. Tree mortality in response to typhoon-induced floods and mudslides is determined by tree species, size, and position in a riparian Formosan gum forest in subtropical Taiwan.

    Science.gov (United States)

    Tzeng, Hsy-Yu; Wang, Wei; Tseng, Yen-Hsueh; Chiu, Ching-An; Kuo, Chu-Chia; Tsai, Shang-Te

    2018-01-01

    Global warming-induced extreme climatic changes have increased the frequency of severe typhoons bringing heavy rains; this has considerably affected the stability of the forest ecosystems. Since the Taiwan 921 earthquake occurred in 21 September 1999, the mountain geology of the Island of Taiwan has become unstable and typhoon-induced floods and mudslides have changed the topography and geomorphology of the area; this has further affected the stability and functions of the riparian ecosystem. In this study, the vegetation of the unique Aowanda Formosan gum forest in Central Taiwan was monitored for 3 years after the occurrence of floods and mudslides during 2009-2011. Tree growth and survival, effects of floods and mudslides, and factors influencing tree survival were investigated. We hypothesized that (1) the effects of floods on the survival are significantly different for each tree species; (2) tree diameter at breast height (DBH) affects tree survival-i.e., the larger the DBH, the higher the survival rate; and (3) the relative position of trees affects tree survival after disturbances by floods and mudslides-the farther trees are from the river, the higher is their survival rate. Our results showed that after floods and mudslides, the lifespans of the major tree species varied significantly. Liquidambar formosana displayed the highest flood tolerance, and the trunks of Lagerstoemia subcostata began rooting after disturbances. Multiple regression analysis indicated that factors such as species, DBH, distance from sampled tree to the above boundary of sample plot (far from the riverbank), and distance from the upstream of the river affected the lifespans of trees; the three factors affected each tree species to different degrees. Furthermore, we showed that insect infestation had a critical role in determining tree survival rate. Our 3-year monitoring investigation revealed that severe typhoon-induced floods and mudslides disturbed the riparian vegetation in the

  14. Potential tree species for use in the restoration of unsanitary landfills.

    Science.gov (United States)

    Kim, Kee Dae; Lee, Eun Ju

    2005-07-01

    Given that they represent the most economical option for disposing of refuse, waste landfills are widespread in urban areas. However, landfills generate air and water pollution and require restoration for landscape development. A number of unsanitary waste landfills have caused severe environmental problems in developing countries. This study aimed to investigate the colonization status of different tree species on waste landfills to assess their potential for restoring unsanitary landfills in South Korea. Plot surveys were conducted using 10 x 10-m quadrats at seven waste landfill sites: Bunsuri, Dugiri, Hasanundong, Gomaeri, Kyongseodong, Mojeonri, and Shindaedong. We determined the height, diameter at breast height (DBH), and number of tree species in the plots, and enumerated all saplings landfills, we measured the distance from the presumed mother plant (i.e., the tallest black locust in a patch), height, and DBH of all individuals in black locust patches to determine patch structure. Robinia pseudoacacia, Salix koreensis, and Populus sieboldii formed canopy layers in the waste landfills. The basal area of black locust was 1.51 m(2)/ha, and this species had the highest number of saplings among all tree species. The diameter of the black locust patches ranged from 3.71 to 11.29 m. As the patch diameter increased, the number of regenerated saplings also tended to increase, albeit not significantly. Black locust invaded via bud banks and spread clonally in a concentric pattern across the landfills. This species grew well in the dry habitat of the landfills, and its growth rate was very high. Furthermore, black locust has the ability to fix nitrogen symbiotically; it is therefore considered a well-adapted species for waste landfills. Eleven woody species were selected for screening: Acer palmatum, Albizzia julibrissin, Buxus microphylla var. koreana, Ginkgo biloba, Hibiscus syriacus, Koelreuteria paniculata, Ligustrum obtusifolium, Liriodendron tulipifera, Pinus

  15. Divergent Hydraulic Safety Strategies in Three Co-occurring Anacardiaceae Tree Species in a Chinese Savanna.

    Science.gov (United States)

    Zhang, Shu-Bin; Zhang, Jiao-Lin; Cao, Kun-Fang

    2016-01-01

    Vulnerability segmentation, the condition under which plant leaves are more vulnerable to drought-induced cavitation than stems, may act as a "safety valve" to protect stems from hydraulic failure. Evergreen, winter-deciduous, and drought-deciduous tree species co-occur in tropical savannas, but there have been no direct studies on the role of vulnerability segmentation and stomatal regulation in maintaining hydraulic safety in trees with these three leaf phenologies. To this end, we selected three Anacardiaceae tree species co-occurring in a Chinese savanna, evergreen Pistacia weinmanniifolia , drought-deciduous Terminthia paniculata , and winter-deciduous Lannea coromandelica , to study inter-species differentiation in leaf and stem hydraulic safety. We found that the two deciduous species had significantly higher sapwood-specific hydraulic conductivity and leaf-specific hydraulic conductance than the evergreen species. Moreover, two deciduous species were more vulnerable to stem cavitation than the evergreen species, although both drought-deciduous species and evergreen species had drought-resistance leaves. The evergreen species maintained a wide hydraulic safety margin (HSM) in stems and leaves; which was achieved by embolism resistance of both stems and leaves and isohydric stomatal control. Both deciduous species had limited HSMs in stems and leaves, being isohydric in the winter-deciduous species and anisohydric in drought-deciduous species. The difference in water potential at 50% loss of hydraulic conductivity between the leaves and the terminal stems (P50 leaf-stem ) was positive in P. weinmanniifolia and L. coromandelica , whereas, T. paniculata exhibited a lack of vulnerability segmentation. In addition, differences in hydraulic architecture were found to be closely related to other structural traits, i.e., leaf mass per area, wood density, and sapwood anatomy. Overall, the winter-deciduous species exhibits a drought-avoidance strategy that maintains

  16. Instrumental neutron activation analysis of tree rings for dendrochemical studies

    International Nuclear Information System (INIS)

    Schaumloffel, J.C.; Filby, R.H.

    1996-01-01

    Instrumental neutron activation analysis (INAA) was employed to determine zinc, cadmium and potassium concentrations in the growth rings of ponderosa pine (Pinus ponderosa Dougl.) trees growing along the shores of Lake Roosevelt in Washington State, U.S.A. where mineral processing activities have resulted in high burdens of zinc and cadmium in the lake sediments. The tree growing along the contaminated waterway display elevated concentrations of zinc in its growth rings relative to a tree growing along an uncontaminated tributary of Lake Roosevelt. Cadmium concentrations in the growth rings from both sites are similar from 1988 to 1993. Water quality data indicate an increased concentration of cadmium in the lake from 1984 to 1988. The increased concentrations of cadmium in the lake water were reflected in apparent increases in concentrations of cadmium in individual rings of the tree sampled at the contaminated site. This suggests that translocation of cadmium in the sapwood of heartwood-forming species does not occur in the short term, and thus may not be a limiting factor in using trees as environmental monitors for cadmium. In addition, five-year tree ring segments were analyzed and subsequently reanalyzed as individual single-year ring segments. The analytical data obtained for the pooled individual rings are essentially the same as for the five-year segments, demonstrating the utility of NAA for dendrochemical studies. (author). 24 refs., 5 figs., 2 tabs

  17. Tree species effects on pathogen-suppressive capacities of soil bacteria across two tropical dry forests in Costa Rica.

    Science.gov (United States)

    Becklund, Kristen; Powers, Jennifer; Kinkel, Linda

    2016-11-01

    Antibiotic-producing bacteria in the genus Streptomyces can inhibit soil-borne plant pathogens, and have the potential to mediate the impacts of disease on plant communities. Little is known about how antibiotic production varies among soil communities in tropical forests, despite a long history of interest in the role of soil-borne pathogens in these ecosystems. Our objective was to determine how tree species and soils influence variation in antibiotic-mediated pathogen suppression among Streptomyces communities in two tropical dry forest sites (Santa Rosa and Palo Verde). We targeted tree species that co-occur in both sites and used a culture-based functional assay to quantify pathogen-suppressive capacities of Streptomyces communities beneath 50 focal trees. We also measured host-associated litter and soil element concentrations as potential mechanisms by which trees may influence soil microbes. Pathogen-suppressive capacities of Streptomyces communities varied within and among tree species, and inhibitory phenotypes were significantly related to soil and litter element concentrations. Average proportions of inhibitory Streptomyces in soils from the same tree species varied between 1.6 and 3.3-fold between sites. Densities and proportions of pathogen-suppressive bacteria were always higher in Santa Rosa than Palo Verde. Our results suggest that spatial heterogeneity in the potential for antibiotic-mediated disease suppression is shaped by tree species, site, and soil characteristics, which could have significant implications for understanding plant community composition and diversity in tropical dry forests.

  18. Population Development of Several Species of Ants on the Cocoa Trees in South Sulawesi

    Directory of Open Access Journals (Sweden)

    Fatahuddin Fatahuddin

    2010-08-01

    Full Text Available Several species of ants with different behavior have been found in cocoa plantations and their behavior is important to be considered because it might be correlated with the degree of protection of cocoa plant from cocoa pests. The aim of this research is to manipulate and to develop ants population in environment, so they are able to establish permanently in cocoa trees. This research was conducted in Papakaju Regions Luwu Regency in Juli to November 2009. In this study, 10 cocoa trees with ants were sampled (each species of ant in 10 cocoa trees. A control of 10 tree samples without ant was also taken. In order to assess the abundance of ant population, it was grouped based on scoring, which score 1 for less than 20 ants, score 2 for 21–50 ants, score 3 for 51–200 ants, score 4 for 201–1000 ants, and score 5 for more than 1000 per tree. The results indicated that average of population score of the three ants species reached the highest population for the Oecophylla. smaragdina with average score 4.85 (>1000 ants, Dolichoderus thoracicus, with average score 3.90 (> 200 ants and Crematogaster. difformis with average score 3.10 (>200 ants. This research indicated that three species of ants, Oecophylla smaragdina (weaver ant, Dolichoderus thoracicus (cocoa black ant and Crematogaster difformis (cracking ant. in farmer cocoa plantations in South Sulawesi giving better performance against major pests of cocoa in particular cocoa pod borer (CPB. Key words: Ant Population, Oecophylla smaragdina, Dolichoderus thoracicus, Crematogaster difformis, artificial nest, cocoa.

  19. Meta-analysis Reveals that Hydraulic Traits Explain Cross-Species Patterns of Drought-Induced Tree Mortality across the Globe

    Science.gov (United States)

    Anderegg, W.

    2016-12-01

    Drought-induced tree mortality has been observed globally and is expected to increase under climate change scenarios, with large potential consequences for the terrestrial carbon sink. Predicting mortality across species is crucial for assessing the effects of climate extremes on forest community biodiversity, composition, and carbon sequestration. However, the physiological traits associated with elevated risk of mortality in diverse ecosystems remain unknown, though these could greatly improve understanding and prediction of tree mortality in forests. We performed a meta-analysis on species' mortality rates across 475 species from 33 studies around the globe to assess which traits determine a species' mortality risk. We found that species-specific mortality anomalies from community mortality rate in a given drought were associated with plant hydraulic traits. Across all species, mortality was best predicted by a low hydraulic safety margin - the difference between typical minimum xylem water potential and that causing xylem dysfunction - and xylem vulnerability to embolism. Angiosperms and gymnosperms experienced roughly equal mortality risk. Our results provide broad support that hydraulic traits capture key mechanisms determining tree death and highlight that physiological traits can improve vegetation models' prediction of tree mortality during climate extremes. We conclude with thoughts about a revised framework for future tree mortality research.

  20. Leaf waxes of slow-growing alpine and fast-growing lowland Poa species: inherent differences and responses to UV-B radiation

    International Nuclear Information System (INIS)

    Pilon, J.J.; Lambers, H.; Baas, W.; Tosserams, M.; Rozema, J.; Atkin, O.K.

    1999-01-01

    We investigated whether alpine and lowland Poa species exhibit inherent differences in leaf cuticular waxes, leaf UV absorbing compounds and/or growth responses to UV-B treatment. All plants were grown hydroponically in a growth cabinet (constant 20°; 14 hr photoperiod; 520 μmol photons m −2 s −1 PAR). Two alpine (P. fawcettiae and P. costiniana), one sub-alpine (P. alpina) and three temperate lowland species (P. pratensis, P. compressa and P. trivialis) were grown under conditions without UV radiation for 36 days. In a subsequent experiment, four Poa species (P. costiniana, P. alpina, P. compressa and P. trivialis) were also exposed for 21 days to UV-B/(UV-A) radiation ('UV-B treatment') that resulted in daily UV-B radiation of 7.5 kJ m −2 day −1 , with control plants being grown without UV-B ('UV-A control treatment'). All treatments were carried out in the same growth cabinet. There was no altitudinal trend regarding wax concentrations per unit leaf area, when the six species grown under UV-less conditions, were compared at similar developmental stage (20–30 g shoot fresh mass). However, large differences in cuticular wax chemical composition were observed between the alpine and lowland species grown under UV-less conditions. For example, a single primary alcohol was present in the waxes of the lowland and sub-alpine species (C 26 H 53 OH), but was virtually absent in the alpine species. Although alkanes were present in all six species (primarily C 29 H 60 and C 31 H 64 ), the proportion of total wax present as alkanes was highest in the alpine species. Aldehydes were only present in the waxes of the alpine species. Conversely, substantial amounts of triterpenoids were mainly present in the three lowland species (squalene and lupeol were the dominant forms). The proportion of total wax present as long-chain esters (LCE-s) was similar in all six species grown in the absence of UV radiation. Acetates were observed only in the wax of

  1. Impact of deep coalescence on the reliability of species tree inference from different types of DNA markers in mammals.

    Directory of Open Access Journals (Sweden)

    Alejandro Sánchez-Gracia

    Full Text Available An important challenge for phylogenetic studies of closely related species is the existence of deep coalescence and gene tree heterogeneity. However, their effects can vary between species and they are often neglected in phylogenetic analyses. In addition, a practical problem in the reconstruction of shallow phylogenies is to determine the most efficient set of DNA markers for a reliable estimation. To address these questions, we conducted a multilocus simulation study using empirical values of nucleotide diversity and substitution rates obtained from a wide range of mammals and evaluated the performance of both gene tree and species tree approaches to recover the known speciation times and topological relationships. We first show that deep coalescence can be a serious problem, more than usually assumed, for the estimation of speciation times in mammals using traditional gene trees. Furthermore, we tested the performance of different sets of DNA markers in the determination of species trees using a coalescent approach. Although the best estimates of speciation times were obtained, as expected, with the use of an increasing number of nuclear loci, our results show that similar estimations can be obtained with a much lower number of genes and the incorporation of a mitochondrial marker, with its high information content. Thus, the use of the combined information of both nuclear and mitochondrial markers in a species tree framework is the most efficient option to estimate recent speciation times and, consequently, the underlying species tree.

  2. Quantitative and qualitative characteristics of cell wall components and prenyl lipids in the leaves of Tilia x euchlora trees growing under salt stress.

    Science.gov (United States)

    Milewska-Hendel, Anna; Baczewska, Aneta H; Sala, Katarzyna; Dmuchowski, Wojciech; Brągoszewska, Paulina; Gozdowski, Dariusz; Jozwiak, Adam; Chojnacki, Tadeusz; Swiezewska, Ewa; Kurczynska, Ewa

    2017-01-01

    The study was focused on assessing the presence of arabinogalactan proteins (AGPs) and pectins within the cell walls as well as prenyl lipids, sodium and chlorine content in leaves of Tilia x euchlora trees. The leaves that were analyzed were collected from trees with and without signs of damage that were all growing in the same salt stress conditions. The reason for undertaking these investigations was the observations over many years that indicated that there are trees that present a healthy appearance and trees that have visible symptoms of decay in the same habitat. Leaf samples were collected from trees growing in the median strip between roadways that have been intensively salted during the winter season for many years. The sodium content was determined using atomic spectrophotometry, chloride using potentiometric titration and poly-isoprenoids using HPLC/UV. AGPs and pectins were determined using immunohistochemistry methods. The immunohistochemical analysis showed that rhamnogalacturonans I (RG-I) and homogalacturonans were differentially distributed in leaves from healthy trees in contrast to leaves from injured trees. In the case of AGPs, the most visible difference was the presence of the JIM16 epitope. Chemical analyses of sodium and chloride showed that in the leaves from injured trees, the level of these ions was higher than in the leaves from healthy trees. Based on chromatographic analysis, four poly-isoprenoid alcohols were identified in the leaves of T. x euchlora. The levels of these lipids were higher in the leaves from healthy trees. The results suggest that the differences that were detected in the apoplast and symplasm may be part of the defensive strategy of T. x euchlora trees to salt stress, which rely on changes in the chemical composition of the cell wall with respect to the pectic and AGP epitopes and an increased synthesis of prenyl lipids.

  3. Epigenetic variability in the genetically uniform forest tree species Pinus pinea L.

    Science.gov (United States)

    Sáez-Laguna, Enrique; Guevara, María-Ángeles; Díaz, Luis-Manuel; Sánchez-Gómez, David; Collada, Carmen; Aranda, Ismael; Cervera, María-Teresa

    2014-01-01

    There is an increasing interest in understanding the role of epigenetic variability in forest species and how it may contribute to their rapid adaptation to changing environments. In this study we have conducted a genome-wide analysis of cytosine methylation pattern in Pinus pinea, a species characterized by very low levels of genetic variation and a remarkable degree of phenotypic plasticity. DNA methylation profiles of different vegetatively propagated trees from representative natural Spanish populations of P. pinea were analyzed with the Methylation Sensitive Amplified Polymorphism (MSAP) technique. A high degree of cytosine methylation was detected (64.36% of all scored DNA fragments). Furthermore, high levels of epigenetic variation were observed among the studied individuals. This high epigenetic variation found in P. pinea contrasted with the lack of genetic variation based on Amplified Fragment Length Polymorphism (AFLP) data. In this manner, variable epigenetic markers clearly discriminate individuals and differentiates two well represented populations while the lack of genetic variation revealed with the AFLP markers fail to differentiate at both, individual or population levels. In addition, the use of different replicated trees allowed identifying common polymorphic methylation sensitive MSAP markers among replicates of a given propagated tree. This set of MSAPs allowed discrimination of the 70% of the analyzed trees.

  4. Epigenetic variability in the genetically uniform forest tree species Pinus pinea L.

    Directory of Open Access Journals (Sweden)

    Enrique Sáez-Laguna

    Full Text Available There is an increasing interest in understanding the role of epigenetic variability in forest species and how it may contribute to their rapid adaptation to changing environments. In this study we have conducted a genome-wide analysis of cytosine methylation pattern in Pinus pinea, a species characterized by very low levels of genetic variation and a remarkable degree of phenotypic plasticity. DNA methylation profiles of different vegetatively propagated trees from representative natural Spanish populations of P. pinea were analyzed with the Methylation Sensitive Amplified Polymorphism (MSAP technique. A high degree of cytosine methylation was detected (64.36% of all scored DNA fragments. Furthermore, high levels of epigenetic variation were observed among the studied individuals. This high epigenetic variation found in P. pinea contrasted with the lack of genetic variation based on Amplified Fragment Length Polymorphism (AFLP data. In this manner, variable epigenetic markers clearly discriminate individuals and differentiates two well represented populations while the lack of genetic variation revealed with the AFLP markers fail to differentiate at both, individual or population levels. In addition, the use of different replicated trees allowed identifying common polymorphic methylation sensitive MSAP markers among replicates of a given propagated tree. This set of MSAPs allowed discrimination of the 70% of the analyzed trees.

  5. Seasonal shift in climatic limiting factors on tree transpiration: evidence from sap flow observations at alpine treelines in southeast Tibet

    Directory of Open Access Journals (Sweden)

    Liu Xinsheng

    2016-07-01

    Full Text Available Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstice, which generally results in low transpiration in the early growing season. Sap flow, meteorological factors and predawn needle water potential were continuously monitored throughout one growing season across Smith fir (Abies georgei var. smithii and juniper (Juniperus saltuaria treelines in southeast Tibet. Sap flow started in early May and corresponded to a threshold mean air-temperature of 0 oC. Across tree species, transpiration was mainly limited by low soil temperature prior to the summer solstice but by vapor pressure deficit and solar radiation post-summer solstice, which was further confirmed on a daily scale. As a result, tree transpiration for both tree species was significantly reduced in the pre-summer solstice period as compared to post-summer solstice, resulting in a lower predawn needle water potential for Smith fir trees in the early growing season. Our data supported the hypothesis, suggesting that tree transpiration mainly responds to soil temperature variations in the early growing season. The results are important for understanding the hydrological response of cold-limited forest ecosystems to climate change.

  6. Plasma mass density, species mix and fluctuation diagnostics using fast Alfven wave

    International Nuclear Information System (INIS)

    Ikezi, H.; deGrassie, J.S.; Pinsker, R.I.; Snider, R.T.

    1996-06-01

    The authors propose to employ a fast Alfven wave interferometer and reflectometer as a tokamak diagnostic to measure the plasma mass density, D-T species mix profile, and density fluctuations. Utilize the property that the phase velocity of the fast wave propagating across the magnetic field is the Alfven speed with thermal correction, this fast wave interferometer on the DIII-D tokamak was successfully used to obtain the line integrated density. Since the position of the ion-ion hybrid cut-off in tokamaks is uniquely determined by the species mix ratio and the wave frequency, the reflectometer arrangement finds the species mix profile. The inversion method of reflectometry is discussed. The multiple chord interferometer also measures the mass density fluctuation profile

  7. Plasma mass density, species mix and fluctuation diagnostics using fast Alfven wave

    Energy Technology Data Exchange (ETDEWEB)

    Ikezi, H.; deGrassie, J.S.; Pinsker, R.I.; Snider, R.T.

    1996-06-01

    The authors propose to employ a fast Alfven wave interferometer and reflectometer as a tokamak diagnostic to measure the plasma mass density, D-T species mix profile, and density fluctuations. Utilize the property that the phase velocity of the fast wave propagating across the magnetic field is the Alfven speed with thermal correction, this fast wave interferometer on the DIII-D tokamak was successfully used to obtain the line integrated density. Since the position of the ion-ion hybrid cut-off in tokamaks is uniquely determined by the species mix ratio and the wave frequency, the reflectometer arrangement finds the species mix profile. The inversion method of reflectometry is discussed. The multiple chord interferometer also measures the mass density fluctuation profile.

  8. Evaluating the phylogenetic signal limit from mitogenomes, slow evolving nuclear genes, and the concatenation approach. New insights into the Lacertini radiation using fast evolving nuclear genes and species trees.

    Science.gov (United States)

    Mendes, Joana; Harris, D James; Carranza, Salvador; Salvi, Daniele

    2016-07-01

    Estimating the phylogeny of lacertid lizards, and particularly the tribe Lacertini has been challenging, possibly due to the fast radiation of this group resulting in a hard polytomy. However this is still an open question, as concatenated data primarily from mitochondrial markers have been used so far whereas in a recent phylogeny based on a compilation of these data within a squamate supermatrix the basal polytomy seems to be resolved. In this study, we estimate phylogenetic relationships between all Lacertini genera using for the first time DNA sequences from five fast evolving nuclear genes (acm4, mc1r, pdc, βfib and reln) and two mitochondrial genes (nd4 and 12S). We generated a total of 529 sequences from 88 species and used Maximum Likelihood and Bayesian Inference methods based on concatenated multilocus dataset as well as a coalescent-based species tree approach with the aim of (i) shedding light on the basal relationships of Lacertini (ii) assessing the monophyly of genera which were previously questioned, and (iii) discussing differences between estimates from this and previous studies based on different markers, and phylogenetic methods. Results uncovered (i) a new phylogenetic clade formed by the monotypic genera Archaeolacerta, Zootoca, Teira and Scelarcis; and (ii) support for the monophyly of the Algyroides clade, with two sister species pairs represented by western (A. marchi and A. fitzingeri) and eastern (A. nigropunctatus and A. moreoticus) lineages. In both cases the members of these groups show peculiar morphology and very different geographical distributions, suggesting that they are relictual groups that were once diverse and widespread. They probably originated about 11-13 million years ago during early events of speciation in the tribe, and the split between their members is estimated to be only slightly older. This scenario may explain why mitochondrial markers (possibly saturated at higher divergence levels) or slower nuclear markers

  9. Meta-transcriptomics indicates biotic cross-tolerance in willow trees cultivated on petroleum hydrocarbon contaminated soil.

    Science.gov (United States)

    Gonzalez, Emmanuel; Brereton, Nicholas J B; Marleau, Julie; Guidi Nissim, Werther; Labrecque, Michel; Pitre, Frederic E; Joly, Simon

    2015-10-12

    High concentrations of petroleum hydrocarbon (PHC) pollution can be hazardous to human health and leave soils incapable of supporting agricultural crops. A cheap solution, which can help restore biodiversity and bring land back to productivity, is cultivation of high biomass yielding willow trees. However, the genetic mechanisms which allow these fast-growing trees to tolerate PHCs are as yet unclear. Salix purpurea 'Fish Creek' trees were pot-grown in soil from a former petroleum refinery, either lacking or enriched with C10-C50 PHCs. De novo assembled transcriptomes were compared between tree organs and impartially annotated without a priori constraint to any organism. Over 45% of differentially expressed genes originated from foreign organisms, the majority from the two-spotted spidermite, Tetranychus urticae. Over 99% of T. urticae transcripts were differentially expressed with greater abundance in non-contaminated trees. Plant transcripts involved in the polypropanoid pathway, including phenylalanine ammonia-lyase (PAL), had greater expression in contaminated trees whereas most resistance genes showed higher expression in non-contaminated trees. The impartial approach to annotation of the de novo transcriptomes, allowing for the possibility for multiple species identification, was essential for interpretation of the crop's response treatment. The meta-transcriptomic pattern of expression suggests a cross-tolerance mechanism whereby abiotic stress resistance systems provide improved biotic resistance. These findings highlight a valuable but complex biotic and abiotic stress response to real-world, multidimensional contamination which could, in part, help explain why crops such as willow can produce uniquely high biomass yields on challenging marginal land.

  10. Tree species classification using within crown localization of waveform LiDAR attributes

    Science.gov (United States)

    Blomley, Rosmarie; Hovi, Aarne; Weinmann, Martin; Hinz, Stefan; Korpela, Ilkka; Jutzi, Boris

    2017-11-01

    Since forest planning is increasingly taking an ecological, diversity-oriented perspective into account, remote sensing technologies are becoming ever more important in assessing existing resources with reduced manual effort. While the light detection and ranging (LiDAR) technology provides a good basis for predictions of tree height and biomass, tree species identification based on this type of data is particularly challenging in structurally heterogeneous forests. In this paper, we analyse existing approaches with respect to the geometrical scale of feature extraction (whole tree, within crown partitions or within laser footprint) and conclude that currently features are always extracted separately from the different scales. Since multi-scale approaches however have proven successful in other applications, we aim to utilize the within-tree-crown distribution of within-footprint signal characteristics as additional features. To do so, a spin image algorithm, originally devised for the extraction of 3D surface features in object recognition, is adapted. This algorithm relies on spinning an image plane around a defined axis, e.g. the tree stem, collecting the number of LiDAR returns or mean values of returns attributes per pixel as respective values. Based on this representation, spin image features are extracted that comprise only those components of highest variability among a given set of library trees. The relative performance and the combined improvement of these spin image features with respect to non-spatial statistical metrics of the waveform (WF) attributes are evaluated for the tree species classification of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and Silver/Downy birch (Betula pendula Roth/Betula pubescens Ehrh.) in a boreal forest environment. This evaluation is performed for two WF LiDAR datasets that differ in footprint size, pulse density at ground, laser wavelength and pulse width. Furthermore, we evaluate the

  11. Project CAPTURE: using forest inventory and analysis data to prioritize tree species for conservation, management, and restoration

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane; William W. Hargrove

    2015-01-01

    A variety of threats, most importantly climate change and insect and disease infestation, will increase the likelihood that forest tree species could experience population-level extirpation or species-level extinction during the next century. Project CAPTURE (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) is a cooperative effort...

  12. Neighboring trees affect ectomycorrhizal fungal community composition in a woodland-forest ecotone.

    Science.gov (United States)

    Hubert, Nathaniel A; Gehring, Catherine A

    2008-09-01

    Ectomycorrhizal fungi (EMF) are frequently species rich and functionally diverse; yet, our knowledge of the environmental factors that influence local EMF diversity and species composition remains poor. In particular, little is known about the influence of neighboring plants on EMF community structure. We tested the hypothesis that the EMF of plants with heterospecific neighbors would differ in species richness and community composition from the EMF of plants with conspecific neighbors. We conducted our study at the ecotone between pinyon (Pinus edulis)-juniper (Juniperus monosperma) woodland and ponderosa pine (Pinus ponderosa) forest in northern Arizona, USA where the dominant trees formed associations with either EMF (P. edulis and P. ponderosa) or arbuscular mycorrhizal fungi (AMF; J. monosperma). We also compared the EMF communities of pinyon and ponderosa pines where their rhizospheres overlapped. The EMF community composition, but not species richness of pinyon pines was significantly influenced by neighboring AM juniper, but not by neighboring EM ponderosa pine. Ponderosa pine EMF communities were different in species composition when growing in association with pinyon pine than when growing in association with a conspecific. The EMF communities of pinyon and ponderosa pines were similar where their rhizospheres overlapped consisting of primarily the same species in similar relative abundance. Our findings suggest that neighboring tree species identity shaped EMF community structure, but that these effects were specific to host-neighbor combinations. The overlap in community composition between pinyon pine and ponderosa pine suggests that these tree species may serve as reservoirs of EMF inoculum for one another.

  13. Video data of flowers, fruitlets, and fruit in apple trees during the 2017 growing season at USDA-ARS-AFRS

    Science.gov (United States)

    This record contains videos of apple trees acquired from a ground vehicle throughout the growing season at the USDA-ARS, Appalachian Fruit Research Station. Research in precision management methods in orchard crops revolve around locating objects of interest, namely flowers, fruitlets, and fruit, a...

  14. Soil respiration and rates of soil carbon turnover differ among six common European tree species

    DEFF Research Database (Denmark)

    Vesterdal, Lars; Elberling, Bo; Christiansen, Jesper Riis

    2012-01-01

    replicated at six sites in Denmark. The studied tree species were the broadleaves beech (Fagus sylvatica L.), pedunculate oak (Quercus robur L.), lime (Tilia cordata L.), sycamore maple (Acer pseudoplatanus L.) and ash (Fraxinus excelsior L.) and the conifer Norway spruce (Picea abies (L.) Karst.). Rates....... Soil respiration differed significantly among several species and increased in the order beechmaple... moisture. Carbon turnover rates based on the ratio between R h and C stock were significantly higher in ash than in all other species except maple, and maple also had higher C turnover than spruce. A similar influence of tree species on C turnover was indicated by the litterfall C to forest floor C ratio...

  15. Biomass Production of Some Salt Tolerant Tree Species Grown in Different Ecological Zones of Pakistan

    International Nuclear Information System (INIS)

    Mahmood, K.; Chughtai, M. I.; Awan, A. R.; Waheed, R. A.

    2016-01-01

    A study was carried out to evaluate the biomass production potential of salt tolerant tree species grown in saline environments. For this purpose, 5 sites near Badin, Gawadar, Lahore, Faisalabad and Peshawar in different ecological zones of Pakistan were selected. Plantations of 7 tree species common to all sites including Eucalyptus camaldulensis, Phoenix dactylifera, Acacia nilotica, Acacia ampliceps, Prosopis juliflora, Casurinaobesa and Tamarix aphylla were selected for non-destructive biomass measurements. Five trees from each species at each site were assessed for plant height, girth at breast height, canopy area, canopy shape and number of branches. For destructive biomass estimation, six trees of four species (Eucalyptus camaldulensis, Acacia nilotica, Prosopis juliflora and Tamarix aphylla) were harvested at two sites near Lahore and Faisalabad. Biomass of whole tree and its components like stem, branches, twigs, leaves and fruits were determined. Soil and water resources of these sites were also characterized. Results indicated that E. camaldulensis produced maximum average biomass 329 kg in 81/2 years at soil salinity (EC 1:1) 8.5 to 9.4 dS m/sup -1/ and T. aphylla produced 188 kg at soil salinity 12.8 dS m/sup -1/ in 91/2 years. A. nilotica produced biomass 187 kg at 16.9 dS m/sup -1/ in 10 years at Faisalabad; while at Lahore, 369 kg in 18 years under soil salinity level 7.3 dS m/sup -1/. P. juliflora produced minimum biomass 123 kg at soil salinity 7.1 dS m/sup -1/ in 8 years at Lahore and 278 kg at soil salinity 17.2 dS m/sup -1/ in 16 years at Faisalabad. Both soil and water quality was comparatively better at Gawadar and Faisalabad than other sites. Overall, it is concluded that studied tree species are good performer on salt-affected soils and can make saline areas productive. (author)

  16. Reduced trace element concentrations in fast-growing juvenile Atlantic salmon in natural streams.

    Science.gov (United States)

    Ward, Darren M; Nislow, Keith H; Chen, Celia Y; Folt, Carol L

    2010-05-01

    To assess the effect of rapid individual growth on trace element concentrations in fish, we measured concentrations of seven trace elements (As, Cd, Cs, Hg, Pb, Se, Zn) in stream-dwelling Atlantic salmon (Salmo salar) from 15 sites encompassing a 10-fold range in salmon growth. All salmon were hatched under uniform conditions, released into streams, and sampled approximately 120 days later for trace element analysis. For most elements, element concentrations in salmon tracked those in their prey. Fast-growing salmon had lower concentrations of all elements than slow growers, after accounting for prey concentrations. This pattern held for essential and nonessential elements, as well as elements that accumulate from food and those that can accumulate from water. At the sites with the fastest salmon growth, trace element concentrations in salmon were 37% (Cs) to 86% (Pb) lower than at sites where growth was suppressed. Given that concentrations were generally below levels harmful to salmon and that the pattern was consistent across all elements, we suggest that dilution of elements in larger biomass led to lower concentrations in fast-growing fish. Streams that foster rapid, efficient fish growth may produce fish with lower concentrations of elements potentially toxic for human and wildlife consumers.

  17. Long-term Seedling Dynamics of Tree Species in a Subtropical Rain Forest, Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Hao Chang-Yang

    2013-03-01

    Full Text Available Knowledge of demographical rates at seedling stage is critical for understanding forest composition and dynamics. We monitored the seedling dynamics of tree species in a subtropical rain forest in Fushan, northern Taiwan (24°45’ N, 121°35’ E during an 8-yr period (2003–2010. There were great temporal fluctuations in the seedling density, which might be largely driven by the pulses of seedling recruitment. Interspecific variation in the seedling abundance, however, was not related to the reproductive adult abundance. Previous studies showed that frequent typhoon disturbances contributed to the high canopy openness and high understory light availability at Fushan, which might benefit tree regeneration. But our results do not support this idea. Most of the newly recruited seedlings died within six months and only grew 1.55 ± 0.20 cm per year, which might be suppressed by the dense understory vegetation. Our results suggested that the majority of tree species in Fushan were recruitment limited, which might have important consequences for species coexistence. High temporal variability in recruitment density and low growth rates of seedlings emphasize the importance of long-term studies to our understandings of forest dynamics.

  18. Exotic mammals disperse exotic fungi that promote invasion by exotic trees.

    Science.gov (United States)

    Nuñez, Martin A; Hayward, Jeremy; Horton, Thomas R; Amico, Guillermo C; Dimarco, Romina D; Barrios-Garcia, M Noelia; Simberloff, Daniel

    2013-01-01

    Biological invasions are often complex phenomena because many factors influence their outcome. One key aspect is how non-natives interact with the local biota. Interaction with local species may be especially important for exotic species that require an obligatory mutualist, such as Pinaceae species that need ectomycorrhizal (EM) fungi. EM fungi and seeds of Pinaceae disperse independently, so they may use different vectors. We studied the role of exotic mammals as dispersal agents of EM fungi on Isla Victoria, Argentina, where many Pinaceae species have been introduced. Only a few of these tree species have become invasive, and they are found in high densities only near plantations, partly because these Pinaceae trees lack proper EM fungi when their seeds land far from plantations. Native mammals (a dwarf deer and rodents) are rare around plantations and do not appear to play a role in these invasions. With greenhouse experiments using animal feces as inoculum, plus observational and molecular studies, we found that wild boar and deer, both non-native, are dispersing EM fungi. Approximately 30% of the Pinaceae seedlings growing with feces of wild boar and 15% of the seedlings growing with deer feces were colonized by non-native EM fungi. Seedlings growing in control pots were not colonized by EM fungi. We found a low diversity of fungi colonizing the seedlings, with the hypogeous Rhizopogon as the most abundant genus. Wild boar, a recent introduction to the island, appear to be the main animal dispersing the fungi and may be playing a key role in facilitating the invasion of pine trees and even triggering their spread. These results show that interactions among non-natives help explain pine invasions in our study area.

  19. Multi-rate Poisson tree processes for single-locus species delimitation under maximum likelihood and Markov chain Monte Carlo.

    Science.gov (United States)

    Kapli, P; Lutteropp, S; Zhang, J; Kobert, K; Pavlidis, P; Stamatakis, A; Flouri, T

    2017-06-01

    In recent years, molecular species delimitation has become a routine approach for quantifying and classifying biodiversity. Barcoding methods are of particular importance in large-scale surveys as they promote fast species discovery and biodiversity estimates. Among those, distance-based methods are the most common choice as they scale well with large datasets; however, they are sensitive to similarity threshold parameters and they ignore evolutionary relationships. The recently introduced "Poisson Tree Processes" (PTP) method is a phylogeny-aware approach that does not rely on such thresholds. Yet, two weaknesses of PTP impact its accuracy and practicality when applied to large datasets; it does not account for divergent intraspecific variation and is slow for a large number of sequences. We introduce the multi-rate PTP (mPTP), an improved method that alleviates the theoretical and technical shortcomings of PTP. It incorporates different levels of intraspecific genetic diversity deriving from differences in either the evolutionary history or sampling of each species. Results on empirical data suggest that mPTP is superior to PTP and popular distance-based methods as it, consistently yields more accurate delimitations with respect to the taxonomy (i.e., identifies more taxonomic species, infers species numbers closer to the taxonomy). Moreover, mPTP does not require any similarity threshold as input. The novel dynamic programming algorithm attains a speedup of at least five orders of magnitude compared to PTP, allowing it to delimit species in large (meta-) barcoding data. In addition, Markov Chain Monte Carlo sampling provides a comprehensive evaluation of the inferred delimitation in just a few seconds for millions of steps, independently of tree size. mPTP is implemented in C and is available for download at http://github.com/Pas-Kapli/mptp under the GNU Affero 3 license. A web-service is available at http://mptp.h-its.org . : paschalia.kapli@h-its.org or

  20. Effectiveness of phylogenomic data and coalescent species-tree methods for resolving difficult nodes in the phylogeny of advanced snakes (Serpentes: Caenophidia).

    Science.gov (United States)

    Pyron, R Alexander; Hendry, Catriona R; Chou, Vincent M; Lemmon, Emily M; Lemmon, Alan R; Burbrink, Frank T

    2014-12-01

    Next-generation genomic sequencing promises to quickly and cheaply resolve remaining contentious nodes in the Tree of Life, and facilitates species-tree estimation while taking into account stochastic genealogical discordance among loci. Recent methods for estimating species trees bypass full likelihood-based estimates of the multi-species coalescent, and approximate the true species-tree using simpler summary metrics. These methods converge on the true species-tree with sufficient genomic sampling, even in the anomaly zone. However, no studies have yet evaluated their efficacy on a large-scale phylogenomic dataset, and compared them to previous concatenation strategies. Here, we generate such a dataset for Caenophidian snakes, a group with >2500 species that contains several rapid radiations that were poorly resolved with fewer loci. We generate sequence data for 333 single-copy nuclear loci with ∼100% coverage (∼0% missing data) for 31 major lineages. We estimate phylogenies using neighbor joining, maximum parsimony, maximum likelihood, and three summary species-tree approaches (NJst, STAR, and MP-EST). All methods yield similar resolution and support for most nodes. However, not all methods support monophyly of Caenophidia, with Acrochordidae placed as the sister taxon to Pythonidae in some analyses. Thus, phylogenomic species-tree estimation may occasionally disagree with well-supported relationships from concatenated analyses of small numbers of nuclear or mitochondrial genes, a consideration for future studies. In contrast for at least two diverse, rapid radiations (Lamprophiidae and Colubridae), phylogenomic data and species-tree inference do little to improve resolution and support. Thus, certain nodes may lack strong signal, and larger datasets and more sophisticated analyses may still fail to resolve them. Copyright © 2014 Elsevier Inc. All rights reserved.