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Sample records for saplings

  1. SAPLE: Sandia Advanced Personnel Locator Engine.

    Energy Technology Data Exchange (ETDEWEB)

    Procopio, Michael J.

    2010-04-01

    We present the Sandia Advanced Personnel Locator Engine (SAPLE) web application, a directory search application for use by Sandia National Laboratories personnel. SAPLE's purpose is to return Sandia personnel 'results' as a function of user search queries, with its mission to make it easier and faster to find people at Sandia. To accomplish this, SAPLE breaks from more traditional directory application approaches by aiming to return the correct set of results while placing minimal constraints on the user's query. Two key features form the core of SAPLE: advanced search query interpretation and inexact string matching. SAPLE's query interpretation permits the user to perform compound queries when typing into a single search field; where able, SAPLE infers the type of field that the user intends to search on based on the value of the search term. SAPLE's inexact string matching feature yields a high-quality ranking of personnel search results even when there are no exact matches to the user's query. This paper explores these two key features, describing in detail the architecture and operation of SAPLE. Finally, an extensive analysis on logged search query data taken from an 11-week sample period is presented.

  2. Height of Tallest Saplings in 10-year-old Appalachian Hardwood Clearcuts

    Science.gov (United States)

    H. Clay Smith

    1977-01-01

    Stem characteristics, mainly height, of the tallest hardwood saplings in 10-year-old circular clearcut openings were evaluated for several Appalachian hardwoods in West Virginia. Heights of the tallest saplings were not influenced by cardinal directions on two oak sites. Saplings were taller near the center of 150-, 2OO-, and 250-foot openings than saplings in the...

  3. A system for automatically recording weight changes in sapling trees

    Science.gov (United States)

    Harold F. Haupt; Bud L. Jeffers

    1967-01-01

    Describes an accurate and simple system for taking continuous weight records of sapling-size trees. Measurements obtained using this system have helped in describing the mechanism of interception storage in tree crowns during snowfall.

  4. Seedlings and Saplings - Spears and Didion Ranches [ds318

    Data.gov (United States)

    California Department of Resources — These data are the total number and average number of saplings and seedlings of trees detected from 0.05-ha circular plot habitat samples taken in 2005 at sample...

  5. Genetic diversity increases insect herbivory on oak saplings.

    Directory of Open Access Journals (Sweden)

    Bastien Castagneyrol

    Full Text Available A growing body of evidence from community genetics studies suggests that ecosystem functions supported by plant species richness can also be provided by genetic diversity within plant species. This is not yet true for the diversity-resistance relationship as it is still unclear whether damage by insect herbivores responds to genetic diversity in host plant populations. We developed a manipulative field experiment based on a synthetic community approach, with 15 mixtures of one to four oak (Quercus robur half-sib families. We quantified genetic diversity at the plot level by genotyping all oak saplings and assessed overall damage caused by ectophagous and endophagous herbivores along a gradient of increasing genetic diversity. Damage due to ectophagous herbivores increased with the genetic diversity in oak sapling populations as a result of higher levels of damage in mixtures than in monocultures for all families (complementarity effect rather than because of the presence of more susceptible oak genotypes in mixtures (selection effect. Assemblages of different oak genotypes would benefit polyphagous herbivores via improved host patch location, spill over among neighbouring saplings and diet mixing. By contrast, genetic diversity was a poor predictor of the abundance of endophagous herbivores, which increased with individual sapling apparency. Plant genetic diversity may not provide sufficient functional contrast to prevent tree sapling colonization by specialist herbivores while enhancing the foraging of generalist herbivores. Long term studies are nevertheless required to test whether the effect of genetic diversity on herbivory change with the ontogeny of trees and local adaptation of specialist herbivores.

  6. Early spring leaf out enhances growth and survival of saplings in a temperate deciduous forest.

    Science.gov (United States)

    Augspurger, Carol K

    2008-05-01

    Saplings of many canopy tree species in winter deciduous forests receive the major portion of their light budget for their growing season prior to canopy closure in the spring. This period of high light may be critical for achieving a positive carbon (C) gain, thus contributing strongly to their growth and survival. This study of saplings of Aesculus glabra and Acer saccharum in Trelease Woods, Illinois, USA, tested this hypothesis experimentally by placing tents of shade cloth over saplings during their spring period of high light prior to canopy closure in three consecutive years. Leaf senescence began 16 days (year 0) and 60 days (year 1) earlier for shaded A. glabra saplings than control saplings. No change in senescence occurred for A. saccharum. The annual absolute growth in stem diameter of both species was negligible or negative for shaded saplings, but positive for control saplings. Only 7% of the shaded A. glabra saplings were alive after 2 years, while all control saplings survived for 3 years; only 20% of the shaded A. saccharum saplings survived for 3 years, while 73% of control saplings were alive after the same period. Early spring leaf out is a critical mechanism that allows the long-term persistence of saplings of these species in this winter deciduous forest. Studies and models of C gain, growth, and survival of saplings in deciduous forests may need to take into account their spring phenology because saplings of many species are actually "sun" individuals in the spring prior to their longer period in the summer shade.

  7. Weak trophic interactions among birds, insects and white oak saplings (Quercus alba)

    Science.gov (United States)

    Lichtenberg, J.S.; Lichtenberg, D.A.

    2002-01-01

    We examined the interactions among insectivorous birds, arthropods and white oak saplings (Quercus alba L.) in a temperate deciduous forest under 'open' and 'closed' canopy environments. For 2 y, we compared arthropod densities, leaf damage and sapling growth. Saplings from each canopy environment were assigned to one of four treatments: (1) reference, (2) bird exclosure, (3) insecticide and (4) exclosure + insecticide. Sap-feeding insects were the most abundant arthropod feeding guild encountered and birds reduced sap-feeder densities in 1997, but not in 1998. Although there was no detectable influence of birds on leaf-chewer densities in either year, leaf damage to saplings was greater within bird exclosures than outside of bird exclosures in 1997. Insecticide significantly reduced arthropod densities and leaf damage to saplings, but there was no corresponding increase in sapling growth. Growth and biomass were greater for saplings in more open canopy environments for both years. Sap-feeder densities were higher on closed canopy than open canopy saplings in 1997, but canopy environment did not influence the effects of birds on lower trophic levels. Although previous studies have found birds to indirectly influence plant growth and biomass, birds did not significantly influence the growth or biomass of white oak saplings during our study.

  8. Effects of Channelization on Tree and Sapling Composition in a Green Timber Impoundment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this study was to quantify the difference between the channelized and non-channelized sections of marsh in terms of tree and sapling composition....

  9. Impact of Stand Structure to the Diversity of Tree Sapling in Rubber Agroforest System

    OpenAIRE

    Rasnovi, Saida

    2012-01-01

    The study of stand structure of rubber agroforest system and its effect on tree sapling diversity was carried out in Bungo District, Jambi Province from August 2004 to August 2005. Basal area (BA) and tree density were surveyed using variable-area transect method. Tree sapling species was surveyed using standard plots combined with circular elementary subplots laid along 60 m transect line. The result shown that BA and tree density of rubber agroforest system were lower significantly with for...

  10. Long-Term Survival of Saplings during the Transformation to Continuous Cover

    Directory of Open Access Journals (Sweden)

    Hamish Mackintosh

    2012-09-01

    Full Text Available The Glentress Trial Area is an extensive research area in southern Scotland of 117 ha where a long-term trial of the transformation of even-aged plantations to continuous cover has been in progress since 1952. During the assessment of permanent sample plots in 1990 information on the species and spatial position of saplings (trees taller than 1.3 m with a diameter at breast height of < 7 cm was recorded. This provided a unique opportunity to investigate the long-term survival of saplings during the transformation process when the Trial Area was reassessed in 2009. The main finding was that 37% of saplings survived the 19-year period and the majority developed into trees (≥7 cm diameter at breast height. There was considerable variation between species, the lowest survival of saplings was European larch (Larix decidua Mill. (13% and the highest European beech (Fagus sylvatica L. (55%; however differences between species were not significant. There were, however, significant differences between the six management areas with three with high sapling survival (55% to 61% but others much lower (27% to 32%. If this result is confirmed by other studies, covering a broader range of sites, management guidance that assumes 90% survival will need to be revised.

  11. Do soil fertilization and forest canopy foliage affect the growth and photosynthesis of Amazonian saplings?

    Directory of Open Access Journals (Sweden)

    Nilvanda dos Santos Magalhães

    2014-02-01

    Full Text Available Most Amazonian soils are highly weathered and poor in nutrients. Therefore, photosynthesis and plant growth should positively respond to the addition of mineral nutrients. Surprisingly, no study has been carried out in situ in the central Amazon to address this issue for juvenile trees. The objective of this study was to determine how photosynthetic rates and growth of tree saplings respond to the addition of mineral nutrients, to the variation in leaf area index of the forest canopy, and to changes in soil water content associated with rainfall seasonality. We assessed the effect of adding a slow-release fertilizer. We determined plant growth from 2010 to 2012 and gas exchange in the wet and dry season of 2012. Rainfall seasonality led to variations in soil water content, but it did not affect sapling growth or leaf gas exchange parameters. Although soil amendment increased phosphorus content by 60 %, neither plant growth nor the photosynthetic parameters were influenced by the addition of mineral nutrients. However, photosynthetic rates and growth of saplings decreased as the forest canopy became denser. Even when Amazonian soils are poor in nutrients, photosynthesis and sapling growth are more responsive to slight variations in light availability in the forest understory than to the availability of nutrients. Therefore, the response of saplings to future increases in atmospheric [CO2] will not be limited by the availability of mineral nutrients in the soil.

  12. Aphid infestation affecting the biogeochemistry of European beech saplings

    Science.gov (United States)

    Michalzik, B.; Levia, D. F., Jr.; Bischoff, S.; Näthe, K.

    2014-12-01

    Mass outbreaks of herbivore insects are known to perturb the functional properties of forests. However, it is less clear how endemic to moderate aboveground herbivory affects the vertical flow of nutrients from tree canopies to the soil. Here, we report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). In a potted sapling experiment, we followed the vertical dynamics of nutrients via throughfall (TF), stemflow (SF) and litter leachates (LL) collected over ten weeks underneath infested and uninfested control trees. Aphid infestation amplifies the fluxes of K+, Mn2+ and particulate nitrogen (0.45μm aphid abundance by 26 and 16%, respectively. Differences in canopy-derived dissolved nitrogen and carbon compounds, sulfur (S), Ca2+, Mg2+, Na+ were aphid abundance on nutrient dynamics was most notable in TF and SF and diminished in LL.Aphid infestation greatly altered the SF fluxes of DOC, K+, Mn2+, DON and sulfur-species, which were significantly concentrated at the tree base by "funneling" the rainfall through the canopy biomass to the trunk. Normalized to one square meter, water and nutrient fluxes were amplified by a factor of up to 200 compared to TF.Imaging of leaf surfaces by scanning electron microscopy exhibited notable differences of the surface morphology and microbiology of control, lightly infested, and heavily infested leaves. This observation might point to an aphid-mediated alteration of the phyllosphere ecology triggering the microbial uptake of NH4-N and SO4-S and its transformation to particulate N by magnified biomass growth of the phyllosphere microflora, consequently changing the chemical partitioning and temporal availability of nitrogen.

  13. Osmotic and hydraulic adjustment of mangrove saplings to extreme salinity.

    Science.gov (United States)

    Méndez-Alonzo, Rodrigo; López-Portillo, Jorge; Moctezuma, Coral; Bartlett, Megan K; Sack, Lawren

    2016-12-01

    Salinity tolerance in plant species varies widely due to adaptation and acclimation processes at the cellular and whole-plant scales. In mangroves, extreme substrate salinity induces hydraulic failure and ion excess toxicity and reduces growth and survival, thus suggesting a potentially critical role for physiological acclimation to salinity. We tested the hypothesis that osmotic adjustment, a key type of plasticity that mitigates salinity shock, would take place in coordination with declines in whole-plant hydraulic conductance in a common garden experiment using saplings of three mangrove species with different salinity tolerances (Avicennia germinans L., Rhizophora mangle L. and Laguncularia racemosa (L.) C.F. Gaertn., ordered from higher to lower salinity tolerance). For each mangrove species, four salinity treatments (1, 10, 30 and 50 practical salinity units) were established and the time trajectories were determined for leaf osmotic potential (Ψs), stomatal conductance (gs), whole-plant hydraulic conductance (Kplant) and predawn disequilibrium between xylem and substrate water potentials (Ψpdd). We expected that, for all three species, salinity increments would result in coordinated declines in Ψs, gs and Kplant, and that the Ψpdd would increase with substrate salinity and time of exposure. In concordance with our predictions, reductions in substrate water potential promoted a coordinated decline in Ψs, gs and Kplant, whereas the Ψpdd increased substantially during the first 4 days but dissipated after 7 days, indicating a time lag for equilibration after a change in substratum salinity. Our results show that mangroves confront and partially ameliorate acute salinity stress via simultaneous reductions in Ψs, gs and Kplant, thus developing synergistic physiological responses at the cell and whole-plant scales. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. The impact of overstory density on sapling height growth in the Missouri Ozarks: implications for interspecific differentiation during canopy recruitment

    Science.gov (United States)

    Lance A. Vickers; David R. Larsen; Benjamin O. Knapp; John M. Kabrick; Daniel C. Dey

    2014-01-01

    Successful canopy recruitment is one of the most important components of sustainable forestry practices. For many desirable species in oak-dominated forests, insufficient sapling growth is a common limitation to successful recruitment. The objectives of this study were to (i) examine the impact of overstory density on sapling growth in the Missouri Ozarks, (ii)...

  15. Physiology, morphology, and ozone uptake of leaves of black cherry seedlings, saplings, and canopy trees.

    Science.gov (United States)

    Fredericksen, T S; Joyce, B J; Skelly, J M; Steiner, K C; Kolb, T E; Kouterick, K B; Savage, J E; Snyder, K R

    1995-01-01

    Patterns of ozone uptake were related to physiological, morphological, and phenological characteristics of different-sized black cherry trees (Prunus serotina Ehrh.) at a site in central Pennsylvania. Calculated ozone uptake differed among open-grown seedlings, forest gap saplings, and canopy trees and between leaves in the upper and lower crown of saplings and canopy trees. On an instantaneous basis, seedling leaves had the greatest ozone uptake rates of all tree size classes due to greater stomatal conductance and higher concentrations of ozone in their local environment. A pattern of higher stomatal conductance of seedlings was consistent with higher incident photosynthetically-active radiation, stomatal density, and predawn xylem water potentials for seedlings relative to larger trees. However, seedlings displayed an indeterminate pattern of shoot growth, with the majority of their leaves produced after shoot growth had ceased for canopy and sapling trees. Full leaf expansion occurred by mid-June for sapling and canopy trees. Because many of their leaves were exposed to ozone for only part of the growing season, seedlings had a lower relative exposure over the course of the growing season, and subsequently lower cumulative uptake, of ozone than canopy trees and a level of uptake similar to upper canopy leaves of saplings. Visible injury symptoms were not always correlated with patterns in ozone uptake. Visible symptoms were more apparent on seedling leaves in concurrence with their high instantaneous uptake rates. However, visible injury was more prevalent on leaves in the lower versus upper crown of canopy trees and saplings, even though lower crown leaves had less ozone uptake. Lower crown leaves may be more sensitive to ozone per unit uptake than upper crown leaves because of their morphology. In addition, the lower net carbon uptake of lower crown leaves may limit repair and anti-oxidant defense processes.

  16. Sapling growth rates reveal conspecific negative density dependence in a temperate forest.

    Science.gov (United States)

    Ramage, Benjamin S; Johnson, Daniel J; Gonzalez-Akre, Erika; McShea, William J; Anderson-Teixeira, Kristina J; Bourg, Norman A; Clay, Keith

    2017-10-01

    Local tree species diversity is maintained in part by conspecific negative density dependence (CNDD). This pervasive mechanism occurs in a variety of forms and ecosystems, but research to date has been heavily skewed toward tree seedling survival in tropical forests. To evaluate CNDD more broadly, we investigated how sapling growth rates were affected by conspecific adult neighbors in a fully mapped 25.6 ha temperate deciduous forest. We examined growth rates as a function of the local adult tree neighborhood (via spatial autoregressive modeling) and compared the spatial positioning of faster-growing and slower-growing saplings with respect to adult conspecific and heterospecific trees (via bivariate point pattern analysis). In addition, to determine whether CNDD-driven variation in growth rates leaves a corresponding spatial signal, we extended our point pattern analysis to a static, growth-independent comparison of saplings and the next larger size class. We found that negative conspecific effects on sapling growth were most prevalent. Five of the nine species that were sufficiently abundant for analysis exhibited CNDD, while only one species showed evidence of a positive conspecific effect, and one or two species, depending on the analysis, displayed heterospecific effects. There was general agreement between the autoregressive models and the point pattern analyses based on sapling growth rates, but point pattern analyses based on single-point-in-time size classes yielded results that differed markedly from the other two approaches. Our work adds to the growing body of evidence that CNDD is an important force in temperate forests, and demonstrates that this process extends to sapling growth rates. Further, our findings indicate that point pattern analyses based solely on size classes may fail to detect the process of interest (e.g., neighborhood-driven variation in growth rates), in part due to the confounding of tree size and age.

  17. Response to dehydration and irrigation in invasive and native saplings: osmotic adjustment versus leaf shedding.

    Science.gov (United States)

    Yazaki, Kenichi; Sano, Yuzou; Fujikawa, Seizo; Nakano, Takashi; Ishida, Atsushi

    2010-05-01

    To clarify the mechanism underlying successful invasion by tree species into xeric sites on Japan's Bonin Islands, we compared the water use of an alien species, Psidium cattleianum, which is rapidly expanding on ridge sites with shallow soil, with that of a native species, Trema orientalis. We hypothesized that there is a trade-off between leaf shedding with low cavitation resistance (frequent xylem cavitation plus refilling ability) and leaf osmotic adjustment with high cavitation resistance (cessation of xylem cavitation plus canopy leaf retention), indicating contrasting strategies for drought tolerance and water use in semi-arid regions. We examined leaf turnover, leaf gas exchange, leaf water potential and water distribution in stem xylem conduits using cryo-scanning electron microscopy for the saplings of both species under three cycles of artificial drought and sudden pulse irrigation. Invasive P. cattleianum saplings were highly resistant to cavitation in stem xylem conduits, retained their leaves and exhibited effective leaf osmotic adjustment under the drought treatment. In contrast, native T. orientalis saplings exhibited xylem cavitation, conspicuous leaf shedding and less effective leaf osmotic adjustment under the drought treatment. Leaf gas exchange rate recovered more rapidly in P. cattleianum saplings than in T. orientalis saplings immediately following pulse irrigation after a period without irrigation, especially in the first drought cycle. Embolized conduits in T. orientalis were refilled by pulse irrigation, and leaf gas exchange rate recovered following refilling. The two tree species showed contrasting strategies for drought tolerance and water use along a trade-off axis. Cavitation avoidance and effective leaf osmotic adjustment in P. cattleianum saplings under drought conditions partially support their survival at the xeric ridge sites on the Bonin Islands. Our results help to explain the success of P. cattleianum in its invasion of a sub

  18. Prescribed fire and oak sapling physiology, demography, and folivore damage in an Ozark woodland

    Science.gov (United States)

    D. Alexander Wait; Douglas P. Aubrey

    2014-01-01

    Prescribed fire is a tool in wildlife management for restoring and maintaining midwestern oak woodlands. The success of some of the wildlife management objectives depends upon opening the canopy, new oak (Quercus spp.) saplings entering the canopy, and removal of cedar (Juniperus virginiana L.). We examined population...

  19. IMPACT OF STAND STRUCTURE TO THE DIVERSITY OF TREE SAPLING IN RUBBER AGROFOREST SYSTEM

    Directory of Open Access Journals (Sweden)

    Saida Rasnovi

    2013-10-01

    Full Text Available The study of stand structure of rubber agroforest system and its effect on tree sapling diversity was carried out in Bungo District, Jambi Province from August 2004 to August 2005. Basal area (BA and tree density were surveyed using variable-area transect method. Tree sapling species was surveyed using standard plots combined with circular elementary subplots laid along 60 m transect line. The result shown that BA and tree density of rubber agroforest system were lower significantly with forest at the diameter class > 30 cm, but at the diameter class < 30 cm there were not differ significantly. PCA analysis shown there was a positive correlation between BA non rubber tree with the species diversity and richness indices of tree sapling in rubber agroforest system and there was no correlation between density of non rubber tree and the indices. However, in the forest, BA and tree density were have a negative correlation with the species diversity and richness indices of tree sapling.

  20. Using goats and sheep to control juniper saplings: what we've learned

    Science.gov (United States)

    The primary findings and conclusions were synthesized from a series of papers published between 2006-2014 from studies conducted at CRLRC and the NMSU Campus Farm seeking to determine the feasibility of using sheep and goats to suppress oneseed juniper sapling encroachment. We found that protein sup...

  1. Investigation of cadmium pollution in the spruce saplings near the metal production factory.

    Science.gov (United States)

    Hashemi, Seyed Armin; Farajpour, Ghasem

    2016-02-01

    Toxic metals such as lead and cadmium are among the pollutants that are created by the metal production factories and disseminated in the nature. In order to study the quantity of cadmium pollution in the environment of the metal production factories, 50 saplings of the spruce species at the peripheries of the metal production factories were examined and the samples of the leaves, roots, and stems of saplings planted around the factory and the soil of the environment of the factory were studied to investigate pollution with cadmium. They were compared to the soil and saplings of the spruce trees planted outside the factory as observer region. The results showed that the quantity of pollution in the leaves, stems, and roots of the trees planted inside the factory environment were estimated at 1.1, 1.5, and 2.5 mg/kg, respectively, and this indicated a significant difference with the observer region (p factory was estimated at 6.8 mg/kg in the depth of 0-10 cm beneath the level of the soil. The length of roots in the saplings planted around the factory of metal production stood at 11 and 14.5 cm in the observer region which had a significant difference with the observer region (p pollution with cadmium in the region has been influenced by the production processes in the factory. © The Author(s) 2013.

  2. Twenty-year growth of ponderosa pine saplings thinned to five spacings in central Oregon.

    Science.gov (United States)

    Barrett James W.

    1982-01-01

    Diameter, height, and volume growth and yield are given for plots thinned to 1000, 500, 250, 125, and 62 trees per acre in a 40- to 70-year-old stand of suppressed ponderosa pine (Pinus ponderosa Dougl. ex Laws.) saplings in central Oregon. Trees averaged about 1-inch in diameter and 8 feet in height at the time of thinning. Considerations for...

  3. Belowground competition from overstory trees influences Douglas-fir sapling morphology in thinned stands

    Science.gov (United States)

    Warren D. Devine; Timothy B. Harrington

    2009-01-01

    We evaluated effects of belowground competition on morphology of naturally established coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) saplings in 60- to 80-year-old thinned Douglas-fir stands in southwestern Washington. We separately quantified belowground competition from overstory and understory sources...

  4. Survival and growth of balsam fir seedlings and saplings under multiple controlled ungulate densities

    NARCIS (Netherlands)

    Hidding, B.; Tremblay, J.P.; Cote, S.D.

    2012-01-01

    Tree species composition in forests can be strongly modulated by high densities of cervid herbivores ultimately leading to local extirpation of species. To establish which cervid densities are compatible with the recruitment of a browse sensitive tree species, seedlings and saplings should be

  5. Patterns of vole gnawing on saplings in managed clearings in Central European forests

    Czech Academy of Sciences Publication Activity Database

    Krojerová-Prokešová, Jarmila; Homolka, Miloslav; Heroldová, Marta; Barančeková, Miroslava; Baňař, P.; Kamler, Jiří; Modlinger, R.; Purchart, L.; Zejda, Jan; Suchomel, J.

    2018-01-01

    Roč. 408, January (2018), s. 137-147 ISSN 0378-1127 R&D Projects: GA MZe QH72075 Institutional support: RVO:68081766 Keywords : Bark gnawing * Clear-cuts * Damage * Rodents * Saplings * Small mammals Subject RIV: GK - Forestry Impact factor: 3.064, year: 2016

  6. Cultural practices in Appalachian hardwood sapling stands--are they worthwhile?

    Science.gov (United States)

    Gary W. Miller

    1986-01-01

    Forest managers often question the economic feasibility of cultural practices in hardwood sapling stands. Investment factors, including initial treatment cost, required rate of return, investment period, and stand response to treatment are discussed in terms of how they affect the outcome of early investments in even-aged hardwood stands. Attention is focused on...

  7. Using biologically-fixed nitrogen by native plants to enhance growth of hardwood saplings

    Science.gov (United States)

    J.W. Van Sambeek; Nadia E. Navarrete-Tindall

    2013-01-01

    Available soil nitrogen is frequently low in old-field plantings. Underplanting forage legumes and interplanting nitrogen-fixing shrubs can improve growth of hardwood saplings, especially black walnut and pecan. Most of the nitrogen-fixing shrubs and forbs have been introduced, and several are now considered invasive species. Research trials have been established on...

  8. Fate of recently fixed carbon in European beech (Fagus sylvatica) saplings during drought and subsequent recovery.

    Science.gov (United States)

    Zang, Ulrich; Goisser, Michael; Grams, Thorsten E E; Häberle, Karl-Heinz; Matyssek, Rainer; Matzner, Egbert; Borken, Werner

    2014-01-01

    Drought reduces the carbon (C) assimilation of trees and decouples aboveground from belowground carbon fluxes, but little is known about the response of drought-stressed trees to rewetting. This study aims to assess dynamics and patterns of C allocation in beech saplings under dry and rewetted soil conditions. In October 2010, 5-year-old beech saplings from a forest site were transplanted into 20 l pots. In 2011, the saplings were subjected to different levels of soil drought ranging from non-limiting water supply (control) to severe water limitation with soil water potentials of less than -1.5 MPa. As a physiologically relevant measure of drought, the cumulated soil water potential (i.e., drought stress dose (DSD)) was calculated for the growing season. In late August, the saplings were transferred into a climate chamber and pulse-labeled with (13)C-depleted CO2 (δ(13)C of -47‰). Isotopic signatures in leaf and soil respiration were repeatedly measured. Five days after soil rewetting, a second label was applied using 99 atom% (13)CO2. After another 12 days, the fate of assimilated C in each sapling was assessed by calculating the (13)C mass balance. Photosynthesis decreased by 60% in saplings under severe drought. The mean residence time (MRT) of recent assimilates in leaf respiration was more than three times longer than under non-limited conditions and was positively correlated to DSD. Also, the appearance of the label in soil respiration was delayed. Within 5 days after rewetting, photosynthesis, MRT of recent assimilates in leaf respiration and appearance of the label in soil respiration recovered fully. Despite the fast recovery, less label was recovered in the biomass of the previously drought-stressed plants, which also allocated less C to the root compartment (45 vs 64% in the control). We conclude that beech saplings quickly recover from extreme soil drought, although transitional after-effects prevail in C allocation, possibly due to repair

  9. Effects of submergence on growth and survival of saplings of three wetland trees differing in adaptive mechanisms for flood tolerance

    Directory of Open Access Journals (Sweden)

    Fumiko Iwanaga

    2015-04-01

    Full Text Available Aim of study: Withstanding total submergence and reaeration following submergence is essential for the survival and establishment of wetland species. We focused on “LOES–low oxygen escape syndrome” and “LOQS–low oxygen quiescence syndrome” and compared tolerances to total submergence among wetland woody species differing in morphological adaptation to soil flooding. Area of study, materials and methods: This study examined the survival of 2-year-old saplings of Taxodium distichum and Metasequioia glyptostroboides (LOQS species, and Alnus japonica (LOES species, during and after total submergence. Saplings were completely submerged, then de-submerged to determine trends in survival and growth Main results: The M. glyptostroboides and A. japonica saplings could not survive prolonged submergence for more than 8 weeks, whereas saplings of T. distichum survived for over 2 years. Submerged saplings of all species showed no significant growth or modifications in morphology and anatomy under water, such as shoot elongation, adventitious root formation, and/or aerenchyma development. All T. distichum saplings that were de-submerged in the second year had the same pattern of shoot growth regardless of differences in timing and seasonality of de-submergence. Wood formation in T. distichum saplings ceased during submergence and resumed after de-submergence in spring and summer, but not in autumn. Research highlights: T. distichum saplings, which survived longer submergence periods than A. japonica and M. glyptostroboides, had physiological characteristics, such as suspension of growth and metabolism, which allowed survival of protracted total submergence (at least 2 years when saplings were immersed during the dormant stage before leaf flushing.

  10. Skills in assessing the professional literature (SAPL): a 7-year analysis of student EBD performance.

    Science.gov (United States)

    Katz, Ralph V; Shamia, Hebba A; Dearing, Bianca A; Kang, Paul D S; Li, Lin; Chang, Andy

    2014-09-01

    The primary goal of this project was to describe the level of knowledge acquisition using detailed test performance outcomes of the EBD SAPL curriculum over its first 7-years of implementation at the NYU College of Dentistry. A secondary goal was to compare performance outcomes impact of the full 60 h base SAPL curriculum as taught to 4-year DDS students vs an abbreviated 30 h base SAPL curriculum as taught to 3-year Advanced Placement DDS students. The findings for the period 2004-2010 are reported for 1647 dental students (63.6% 4-year DDS students, 36.3% 3-year Advanced Placement DDS students). The database consisted of the score earned by each student on each individual question of the SAPL course's 4 h final examination in which each student read an original research article and answered all questions on the Literature Analysis Form. The major findings were overall high performance by both groups of students (SAPL exam scores of 85.8 vs 83.7, respectively) as well as very similar outcomes between these two student groups on: 1) recognizing research design elements and on interpreting those design elements for clinical application, 2) detailed performance of knowledge within the specific five traditional sections of research articles, and 3) detailed performance across 18 identified research design topics. In conclusion, both course formats appear to be highly effective for their respective student groups, but should not be interpreted as evidence favoring the shorter format given the different characteristics of the two student groups. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Physiological and morphological responses of pine and willow saplings to post-fire salvage logging

    Science.gov (United States)

    Millions, E. L.; Letts, M. G.; Harvey, T.; Rood, S. B.

    2015-12-01

    With global warming, forest fires may be increasing in frequency, and post-fire salvage logging may become more common. The ecophysiological impacts of this practice on tree saplings remain poorly understood. In this study, we examined the physiological and morphological impacts of increased light intensity, due to post-fire salvage logging, on the conifer Pinus contorta (pine) and deciduous broadleaf Salix lucida (willow) tree and shrub species in the Crowsnest Pass region of southern Alberta. Photosynthetic gas-exchange and plant morphological measurements were taken throughout the summer of 2013 on approximately ten year-old saplings of both species. Neither species exhibited photoinhibition, but different strategies were observed to acclimate to increased light availability. Willow saplings were able to slightly elevate their light-saturated rate of net photosynthesis (Amax) when exposed to higher photosynthetic photon flux density (PPFD), thus increasing their growth rate. Willow also exhibited increased leaf inclination angles and leaf mass per unit area (LMA), to decrease light interception in the salvage-logged plot. By contrast, pine, which exhibited lower Amax and transpiration (E), but higher water-use efficiency (WUE = Amax/E) than willow, increased the rate at which electrons were moved through and away from the photosynthetic apparatus in order to avoid photoinhibition. Acclimation indices were higher in willow saplings, consistent with the hypothesis that species with short-lived foliage exhibit greater acclimation. LMA was higher in pine saplings growing in the logged plot, but whole-plant and branch-level morphological acclimation was limited and more consistent with a response to decreased competition in the logged plot, which had much lower stand density.

  12. Different facets of tree sapling diversity influence browsing intensity by deer dependent on spatial scale.

    Science.gov (United States)

    Ohse, Bettina; Seele, Carolin; Holzwarth, Frédéric; Wirth, Christian

    2017-09-01

    Browsing of tree saplings by deer hampers forest regeneration in mixed forests across Europe and North America. It is well known that tree species are differentially affected by deer browsing, but little is known about how different facets of diversity, such as species richness, identity, and composition, affect browsing intensity at different spatial scales. Using forest inventory data from the Hainich National Park, a mixed deciduous forest in central Germany, we applied a hierarchical approach to model the browsing probability of patches (regional scale) as well as the species-specific proportion of saplings browsed within patches (patch scale). We found that, at the regional scale, the probability that a patch was browsed increased with certain species composition, namely with low abundance of European beech ( Fagus sylvatica L.) and high abundance of European ash ( Fraxinus excelsior L.), whereas at the patch scale, the proportion of saplings browsed per species was mainly determined by the species' identity, providing a "preference ranking" of the 11 tree species under study. Interestingly, at the regional scale, species-rich patches were more likely to be browsed; however, at the patch scale, species-rich patches showed a lower proportion of saplings per species browsed. Presumably, diverse patches attract deer, but satisfy nutritional needs faster, such that fewer saplings need to be browsed. Some forest stand parameters, such as more open canopies, increased the browsing intensity at either scale. By showing the effects that various facets of diversity, as well as environmental parameters, exerted on browsing intensity at the regional as well as patch scale, our study advances the understanding of mammalian herbivore-plant interactions across scales. Our results also indicate which regeneration patches and species are (least) prone to browsing and show the importance of different facets of diversity for the prediction and management of browsing intensity

  13. Microsite affects willow sapling recovery from bank vole (Myodes glareolus) herbivory, but does not affect grazing risk.

    Science.gov (United States)

    Shaw, Rosalind F; Pakeman, Robin J; Young, Mark R; Iason, Glenn R

    2013-08-01

    Large herbivores are often removed or reduced as part of vegetation restoration programmes, but the resultant increase in vegetation biomass and changes in vegetation structure may favour small mammals. Small mammals may have large impacts on plant community composition via granivory and sapling herbivory, and increased small mammal populations may reduce any benefits of large herbivore removal for highly preferred species. This study tested the impacts of small mammal herbivory, microsite characteristics and their interaction on growth and survival of three montane willow species with differing chemical compositions, Salix lapponum, S. myrsinifolia and S. arbuscula. In two separate years, 1-year-old saplings were planted within a 180 ha, large-mammal scrub regeneration exclosure, and either experimentally protected from or exposed to small mammals (bank voles). Saplings were planted in one of two microsite treatments, vegetation mown (to mimic a grazed sward) or disturbed (all above- and below-ground competition removed), and monitored throughout the first year of growth. Approximately 40 % of saplings planted out in each year were damaged by bank voles, but direct mortality due to damage was very low (<2 %). There were no strong species differences in susceptibility to vole damage. Microsite treatment had no impact on the proportion of saplings attacked, but in 2004 saplings in mown microsites were more severely damaged and had smaller increases in size than those in disturbed microsites. In 2003, saplings in mown microsites had smaller increases in stem diameter following attack than those in disturbed microsites. Planting 1-year-old willow saplings into disturbed microsites may aid growth, reduce the severity of small mammal damage and improve recovery following sub-lethal small mammal damage. Restoration management of montane willow scrub should therefore consider manipulating the planting site to provide disturbed areas of soil.

  14. Is there evidence of adaptation to tidal flooding in saplings of baldcypress subjected to different salinity regimes?

    Science.gov (United States)

    Krauss, K.W.; Doyle, T.W.; Howard, R.J.

    2009-01-01

    Plant populations may adapt to environmental conditions over time by developing genetically based morphological or physiological characteristics. For tidal freshwater forested wetlands, we hypothesized that the conditions under which trees developed led to ecotypic difference in response of progeny to hydroperiod. Specifically, we looked for evidence of ecotypic adaptation for tidal flooding at different salinity regimes using growth and ecophysiological characteristics of two tidal and two non-tidal source collections of baldcypress (Taxodium distichum (L.) L.C. Rich) from the southeastern United States. Saplings were subjected to treatments of hydrology (permanent versus tidal flooding) and salinity (0 versus ???2 g l-1) for two and a half growing seasons in a greenhouse environment. Saplings from tidal sources maintained 21-41% lower overall growth and biomass accumulation than saplings from non-tidal sources, while saplings from non-tidal sources maintained 14-19% lower overall rates of net photosynthetic assimilation, leaf transpiration, and stomatal conductance than saplings from tidal sources. However, we found no evidence for growth or physiological enhancement of saplings from tidal sources to tide, or of saplings from non-tidal sources to no tide. All saplings growing under permanent flooding exhibited reduced growth and leaf gas exchange regardless of source, with little evidence for consistent salinity effects across hydroperiods. While we reject our original hypothesis, we suggest that adaptations of coastal baldcypress to broad (rather than narrow) environmental conditions may promote ecophysiological and growth enhancements under a range of global-change-induced stressors, perhaps reflecting a natural resilience to environmental change while precluding adaptations for specific flood regimes.

  15. Growth and posture control strategies in Fagus sylvatica and Acer pseudoplatanus saplings in response to canopy disturbance.

    Science.gov (United States)

    Collet, Catherine; Fournier, Mériem; Ningre, François; Hounzandji, Ablo Paul-Igor; Constant, Thiéry

    2011-06-01

    Forest tree saplings that grow in the understorey undergo frequent changes in their light environment to which they must adapt to ensure their survival and growth. Crown architecture, which plays a critical role in light capture and mechanical stability, is a major component of sapling adaptation to canopy disturbance. Shade-adapted saplings typically have plagiotropic stems and branches. After canopy opening, they need to develop more erect shoots in order to exploit the new light conditions. The objective of this study was to test whether changes in sapling stem inclination occur after canopy opening, and to analyse the morphological changes associated with stem reorientation. A 4-year canopy-opening field experiment with naturally regenerated Fagus sylvatica and Acer pseudoplatanus saplings was conducted. The appearance of new stem axes, stem basal diameter and inclination along the stem were recorded every year after canopy opening. Both species showed considerable stem reorientation resulting primarily from uprighting (more erect) shoot movements in Fagus, and from uprighting movements, shoot elongation and formation of relay shoots in Acer. In both species, the magnitude of shoot uprighting movements was primarily related to initial stem inclination. Both the basal part and the apical part of the stem contributed to uprighting movements. Stem movements did not appear to be limited by stem size or by stem growth. Stem uprighting movements in shade-adapted Fagus and Acer saplings following canopy disturbance were considerable and rapid, suggesting that stem reorientation processes play a significant role in the growth strategy of the species.

  16. Intensive Cleaning Increses Sapling Growth and Browse Production in the Southern Appalachians

    Science.gov (United States)

    Lino Della-Bianca

    1969-01-01

    All woody stems except selected crop trees were cut in an 11-year-old mixed-hardwood sapling stand in the Southern Appalachians to determine the effect of intensive cleaning on crop-tree growth and deer-browse production. During the 6-year post-cleaning period, crop trees in uncleaned compartments produced significantly more basal area and grew more in diameter than...

  17. How do drought and warming influence survival and wood traits of Picea mariana saplings?

    Science.gov (United States)

    Balducci, Lorena; Deslauriers, Annie; Giovannelli, Alessio; Beaulieu, Marilène; Delzon, Sylvain; Rossi, Sergio; Rathgeber, Cyrille B. K.

    2015-01-01

    Warming and drought will occur with increased frequency and intensity at high latitudes in the future. How heat and water stress can influence tree mortality is incompletely understood. The aim of this study was to evaluate how carbon resources, stem hydraulics, and wood anatomy and density determine the ability of black spruce saplings to survive daytime or night-time warming (+ 6 °C in comparison with control) in combination with a drought period. Plant water relations, the dynamics of non-structural carbohydrates and starch, mortality rate, and wood anatomy and density of saplings were monitored. Warming, in conjunction with 25 d of water deficit, increased sapling mortality (10% and 20% in night-time and daytime warming, respectively) compared with the control conditions (0.8%). Drought substantially decreased gas exchange, and also pre-dawn and mid-day leaf water potential to values close to –3MPa which probably induced xylem embolism (xylem air entry point, P 12, being on average around –3MPa for this species). In addition, the recovery of gas exchange never reached the initial pre-stress levels, suggesting a possible loss of xylem hydraulic conductivity associated with cavitation. Consequently, mortality may be due to xylem hydraulic failure. Warmer temperatures limited the replenishment of starch reserves after their seasonal minimum. Lighter wood was formed during the drought period, reflecting a lower carbon allocation to cell wall formation, preventing the adaptation of the hydraulic system to drought. Saplings of black spruce experienced difficulty in adapting under climate change conditions, which might compromise their survival in the future. PMID:25371502

  18. Impact of ozone on the growth of birch (Betula pendula) saplings

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, P.E.; Uddling, J.; Skaerby, L.; Wallin, G.; Sellden, G

    2003-08-01

    Significant correlation was found between reductions of growth and daylight AOT40 for Betula pendula saplings. - Saplings of one half-sib family of birch, Betula pendula, were exposed to three levels of ozone in open-top chambers (OTCs) during two growing seasons 1997-1998. The ozone treatments were non-filtered air (NF, accumulated daylight AOT40 over the two growing seasons of 3.0 {mu}l l{sup -1} h), non-filtered air with extra ozone (NF+, accumulated daylight AOT40 of 27.3 {mu}l l{sup -1} h) and non-filtered air with additional extra ozone (NF++, accumulated daylight AOT40 of 120 {mu}l l{sup -1} h). The birch saplings, including the roots, were harvested after the first and second growing seasons. After the first growing season, the NF++ treatment reduced the total wood biomass by 22%, relative to the NF treatment. There was no further reduction of the total wood biomass in the NF++ treatment after the second growing season. The root biomass was reduced by 30% after the first growing season. The shoot/root ratio, as well as the proportional biomass of leaves, were increased by ozone during both years. The ozone impact on the relative growth rate was estimated to -2% per 10 {mu}l l{sup -1} h daylight AOT40 per growing season.

  19. Low temperature resistance in saplings and ramets of Polylepis sericea in the Venezuelan Andes

    Science.gov (United States)

    Rada, Fermín; García-Núñez, Carlos; Rangel, Sairo

    2009-09-01

    The frequent occurrence of all year-round below zero temperatures in tropical high mountains constitutes a most stressful climatic factor that plants have to confront. Polylepis forests are found well above the continuous forest line and are distributed throughout the Andean range. These trees require particular traits to overcome functional limitations imposed on them at such altitudes. Considering seedling and sapling stages as filter phases in stressful environments, some functional aspects of the regeneration of Polylepis sericea, a species associated to rock outcrops in the Venezuelan Andes, were studied. We characterized microclimatic conditions within a forest, in a forest gap and surrounding open páramo and determined low temperature resistance mechanisms in seedlings, saplings and ramets. Conditions in the forest understory were more stable compared to the forest gaps and open surrounding páramo. Minimum temperatures close to the ground were 3.6 °C lower in the open páramo compared to the forest understory. Maximum temperatures were 9.0 °C higher in the open páramo. Ice nucleation and injury temperatures occurred between -6 and -8 °C for both ramets and saplings, an evidence of frost avoidance to low nighttime temperatures. In this particular forest, this resistance ability is determinant in their island-like distribution in very specific less severe temperature habitats.

  20. Interactions between canopy cover density and regeneration cores of older saplings in Scots pine (Pinus sylvestris L.) stands

    Energy Technology Data Exchange (ETDEWEB)

    Marchi, M.; Nocentini, S.; Ducci, F.

    2016-07-01

    Aim of the study: This paper provides an analysis of growth and survival of twenty–year–old Scots pine saplings in relation to canopy cover density (CCD) gradients, from dense (D–CCD), sparse (S–CCD), and gap (G–CCD) situations. Area of study: Aladag (Bolu) in northern Turkey. Material and methods: Sparse canopy cover density (S–CCD), dense canopy cover density (D–CCD) and gap canopy (G–CCD) were chosen within ten different strip sample plots (10 × 50 m) with sapling regeneration cores. Those regeneration cores were divided into two portions (individuals at the edge and middle of the regeneration cores) and from each portion three individuals was were obtained from a sample. The growth relationships of individual saplings were calculated with stem analyses. Honowski Light Factor (HLF) (ratio of Terminal sprout length (T) to Lateral sprout length (L)) was used to present growth potential measure of seedlings. Main results: The largest sapling regeneration cores were found in the G–CCD followed by S–CCD, and finally D–CCD, all tested for significance with Kruskal–Wallis Test. Compared with saplings in the middle of regeneration cores (crop saplings), those at the edge were always reduced in terms of mean height. Significant difference was only found between the ‘Main Crop’ and the ‘Edge 1’ of the regeneration cores for G–CCD suggesting that sapling regeneration cores are more typical under G–CCD conditions. HLF ratios were greater than 1 with high growth potentials for both CCD gradients (G–CCD and S–CCD) and there were no significant variations between G–CCD and S–CCD for main crop and edges. The thinning after 12–14 years increased sapling growth. However, under D–CCD, growth had virtually ceased. Research highlights: Naturally occurring Scots pine saplings are suppressed by a dense canopy. However, they are tolerant of shade to the extent that they can survive over relatively long time–periods (10–12 years) and

  1. The Evaluation of Fruit Sapling Producing Enterprises by the SWOT Analysis in Hatay Province

    Directory of Open Access Journals (Sweden)

    Nuran Tapkı

    2016-09-01

    Full Text Available In this study, SWOT (Strengths, Weaknesses, Opportunities, Threats analyses is done in order to reveal current status of fruit sapling suppliers in Hatay. Data collected from representative face-to-face surveys using full counting method with totally 92 suppliers in the present study. Current statuses of companies were revealed according to SWOT analyses. Favourable ecological conditions, proximity to citrus growing areas and sea, presence of unemployed person in the family and accessibility were the strengths of selected region. Low educational level, small parcels of land, suppliers without regular records, unconsciousness of producers on organizing were the weakness of the selected region, on the contrary.

  2. Tree water status and growth of saplings and mature Norway spruce (Picea abies at a dry distribution limit

    Directory of Open Access Journals (Sweden)

    Walter eOberhuber

    2015-09-01

    Full Text Available We evaluated the size effect on stem water status and growth in Norway spruce (Picea abies (L. Karst. occurring at the edge of its natural range in a dry inner Alpine environment (750 m asl, Tyrol, Austria. Intra-annual dynamics of stem water deficit (ΔW, maximum daily shrinkage (MDS and radial growth (RG were compared among saplings (stem diameter/height: 2.2 cm/93 cm; n = 7 and mature adult trees (25 cm/12.7 m; n = 6 during 2014. ΔW, MDS and RG were extracted from stem diameter variations, which were continuously recorded by automatic dendrometers and the influence of environmental drivers was evaluated by applying moving correlation analysis (MCA. Additionally, we used Morlet wavelet analysis to assess the differences in cyclic radial stem variations between saplings and mature trees. Results indicate that saplings and mature trees were experiencing water limitation throughout the growing season. However, saplings exhibited a more strained stem water status and higher sensitivity to environmental conditions than mature trees. Hence, the significantly lower radial increments in saplings (0.16 ± 0.03 mm compared to mature trees (0.54 ± 0.14 mm is related to more constrained water status in the former, affecting the rate and duration of RG. The wavelet analysis consistently revealed more distinct diurnal stem variations in saplings compared to mature trees. Intra-annual RG was most closely related to climate variables that influence transpiration, i.e., vapor pressure deficit, relative air humidity, and air temperature. MCA, however, showed pronounced instability of climate-growth relationships, which masked missing temporal or significant correlations when the entire study period (April-October was considered. We conclude that an increase in evaporative demand will impair regeneration and long-term stability of drought-prone inner Alpine Norway spruce forests.

  3. Responses of Acer saccharum canopy trees and saplings to P, K and lime additions under high N deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gradowski, T. [Alberta Univ., Edmonton, AB (Canada). Dept. of Renewable Resources; Thomas, S.C. [Toronto Univ., ON (Canada). Faculty of Forestry

    2008-02-15

    This study examined the physiological and morphological responses of Acer Saccharum canopy trees and 2-year old saplings to non-nitrogenous mineral nutrients. The study was conducted to test 4 hypotheses, notably, (1) that liming increased the availability of phosphate by decreasing soil acidity; (2) that Acer Saccharum showed increased physiological and growth performance in response to liming and phosphorus (P) and potassium (K); (3) that the physiological and growth effects of liming and P and K additions are more pronounced in sapling than in mature canopy trees; and (4) that canopy physiological and shoot extension responses precede radial growth responses in mature trees. Fifty-two mature Acer saccharum trees and 138 saplings were treated with 2 fertilizers and potassium chloride alone or in combination with dolomitic lime. Treatments were applied in a 2-level factorial randomized design to mature trees and to saplings. Mineral soil samples were then collected from depths of between 0 and 30 cm. Concentrations of carbon (C) and nitrogen (N) in mineral soil were determined using combustion analysis. Morphological chemical analyses were also conducted. Growth was examined at 5-year and 2-year intervals in order to examine nutrient addition effects on diameter increment. Data were used in a graphical vector nutrient analysis as well as in an analysis of variance (ANOVA). Results of the study showed that nutrients were adsorbed in the mineral soil and taken up by the trees within 1 year of fertilizer application. Liming had no effect on soil P availability. Both the saplings and the trees showed significant responses to both P and K fertilization and liming, including increased foliar nutrient concentration, leaf size and shoot extension growth. It was concluded that the vector analysis of shoot extension growth was consistent with sufficiency of N, but showed marked limitation of P and co-limitation by calcium (Ca) in saplings. 111 refs., 2 tabs., 5 figs.

  4. Current-year flush and needle development in longleaf pine saplings after a dormant season prescribed fire

    Science.gov (United States)

    Shi-Jean S. Sung; James D. Haywood; Mary Anne S. Sayer

    2015-01-01

    A longleaf pine (Pinus palustris Mill.) field performance study was established in central Louisiana in 2004. The study has received three prescribed burns (February 2006, May 2009, and February 2012) since establishment. In late April 2012, 35 saplings were selected and classified based on ocular estimates of needle mass scorch percentages. Mean...

  5. Rhizophoraceae Mangrove Saplings Use Hypocotyl and Leaf Water Storage Capacity to Cope with Soil Water Salinity Changes

    Science.gov (United States)

    Lechthaler, Silvia; Robert, Elisabeth M. R.; Tonné, Nathalie; Prusova, Alena; Gerkema, Edo; Van As, Henk; Koedam, Nico; Windt, Carel W.

    2016-01-01

    Some of the most striking features of Rhizophoraceae mangrove saplings are their voluminous cylinder-shaped hypocotyls and thickened leaves. The hypocotyls are known to serve as floats during seed dispersal (hydrochory) and store nutrients that allow the seedling to root and settle. In this study we investigate to what degree the hypocotyls and leaves can serve as water reservoirs once seedlings have settled, helping the plant to buffer the rapid water potential changes that are typical for the mangrove environment. We exposed saplings of two Rhizophoraceae species to three levels of salinity (15, 30, and 0–5‰, in that sequence) while non-invasively monitoring changes in hypocotyl and leaf water content by means of mobile NMR sensors. As a proxy for water content, changes in hypocotyl diameter and leaf thickness were monitored by means of dendrometers. Hypocotyl diameter variations were also monitored in the field on a Rhizophora species. The saplings were able to buffer rapid rhizosphere salinity changes using water stored in hypocotyls and leaves, but the largest water storage capacity was found in the leaves. We conclude that in Rhizophora and Bruguiera the hypocotyl offers the bulk of water buffering capacity during the dispersal phase and directly after settlement when only few leaves are present. As saplings develop more leaves, the significance of the leaves as a water storage organ becomes larger than that of the hypocotyl. PMID:27446125

  6. Emerald ash borer biocontrol in ash saplings: The potential for early stage recovery of North American ash trees

    Science.gov (United States)

    Jian J. Duan; Leah S. Bauer; Roy G. Van Driesche

    2017-01-01

    In many parts of North America, ash (Fraxinus) stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees, saplings, basal sprouts, and seedlings. Without a soil seed bank for Fraxinus spp., tree recovery will require survival and maturation of these...

  7. Emerald ash borer biocontrol in ash saplings: the potential for early stage recovery of North American ash

    Science.gov (United States)

    In many parts of North America, ash stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees and young basal sprouts, saplings, and seedlings. Without a seed bank, ash tree recovery will require survival and maturation of these younger cohorts...

  8. Methodology and preliminary results of evaluating stem displacement and assessing root system architecture of longleaf pine saplings

    Science.gov (United States)

    Shi-Jean S. Sung; Daniel J. Leduc; James D. Haywood; Thomas L. Eberhardt; Mary Anne Sword Sayer; Stanley J. Zarnoch

    2012-01-01

    A field experiment of the effects of container cavity size and root pruning type on longleaf pine was established in November, 2004, in central Louisiana. Sapling stems were first observed to be leaning after hurricane Gustav (September, 2008) and again in August, 2009. To examine the relationship between stem displacement and root system architecture, a stem-displaced...

  9. Rhizophoraceae Mangrove Saplings Use Hypocotyl and Leaf Water Storage Capacity to Cope with Soil Water Salinity Changes

    NARCIS (Netherlands)

    Lechthaler, Silvia; Robert, Elisabeth M.R.; Tonné, Nathalie; Prusova, Alena; Gerkema, Edo; As, Van Henk; Koedam, Nico; Windt, Carel W.

    2016-01-01

    Some of the most striking features of Rhizophoraceae mangrove saplings are their voluminous cylinder-shaped hypocotyls and thickened leaves. The hypocotyls are known to serve as floats during seed dispersal (hydrochory) and store nutrients that allow the seedling to root and settle. In this study we

  10. Rhizophoraceae Mangrove Saplings Use Hypocotyl and Leaf Water Storage Capacity to Cope with Soil Water Salinity Changes.

    Science.gov (United States)

    Lechthaler, Silvia; Robert, Elisabeth M R; Tonné, Nathalie; Prusova, Alena; Gerkema, Edo; Van As, Henk; Koedam, Nico; Windt, Carel W

    2016-01-01

    Some of the most striking features of Rhizophoraceae mangrove saplings are their voluminous cylinder-shaped hypocotyls and thickened leaves. The hypocotyls are known to serve as floats during seed dispersal (hydrochory) and store nutrients that allow the seedling to root and settle. In this study we investigate to what degree the hypocotyls and leaves can serve as water reservoirs once seedlings have settled, helping the plant to buffer the rapid water potential changes that are typical for the mangrove environment. We exposed saplings of two Rhizophoraceae species to three levels of salinity (15, 30, and 0-5‰, in that sequence) while non-invasively monitoring changes in hypocotyl and leaf water content by means of mobile NMR sensors. As a proxy for water content, changes in hypocotyl diameter and leaf thickness were monitored by means of dendrometers. Hypocotyl diameter variations were also monitored in the field on a Rhizophora species. The saplings were able to buffer rapid rhizosphere salinity changes using water stored in hypocotyls and leaves, but the largest water storage capacity was found in the leaves. We conclude that in Rhizophora and Bruguiera the hypocotyl offers the bulk of water buffering capacity during the dispersal phase and directly after settlement when only few leaves are present. As saplings develop more leaves, the significance of the leaves as a water storage organ becomes larger than that of the hypocotyl.

  11. The consequences of crown traits for the growth and survival of tree saplings in a Mexican lowland rain forest

    NARCIS (Netherlands)

    Sterck, F.J.; Martinez-Ramos, M.; Dryer-Leal, G.; Rodriguez-Velazquez, J.; Poorter, L.

    2003-01-01

    1. Many studies discuss the adaptive value of plant architecture, but few have actually measured architectural effects on plant growth and survival. In this study, sapling growth and survival are related to crown traits for two tree species, Trophis mexicana (Liebm.) Bur. and Pseudolmedia

  12. Light-related variation in sapling architecture of three shade-tolerant tree species of the Mexican rain forest

    NARCIS (Netherlands)

    Martinez-Sanchez, J.L.; Meave, J.; Bongers, F.

    2008-01-01

    The crown architecture of three shade-tolerant tree species (two subcanopy and one mid-canopy) was analyzed in relation to the light regime of the forest understorey. The aim was to examine to which extent shade-tolerant species variate in their crown architecture. Tree saplings (265) between 50 and

  13. Status of oak seedlings and saplings in the northern United States: implications for sustainability of oak forests

    Science.gov (United States)

    Chris W. Woodall; Randall S. Morin; Jim R. Steinman; Charles H. Perry

    2008-01-01

    Oak species are a substantial component of forest ecosystems in a 24-state region spanning the northern U.S. During recent decades, it has been documented that the health of oak forests has been experiencing large-scale decline. To further evaluate the sustainability of oak forests in nearly half the states of the U.S., the current status of oak seedlings and saplings...

  14. Effects of repeated soil irrigation with liquid biological paper sludge on poplar Populus alba saplings: potential risks and benefits.

    Science.gov (United States)

    Corbel, Sylvain; Bourioug, Mohamed; Alaoui-Sossé, Laurence; Bourgeade, Pascale; Alaoui-Sossé, Badr; Aleya, Lotfi

    2016-11-01

    The authors explored the risks and benefits of repeated irrigation of Populus alba saplings with aqueous paper sludge (APS). Saplings were cultivated in pots of forest soil (3 L) in a greenhouse for 7 weeks and watered twice a week with differing concentrations of APS (0, 10, 20, 30, 50, 75, and 100 % v/v with deionized water). Plant growth and ecophysiological variables along with zinc and aluminum transfer were monitored. A stimulation of plant growth was observed with sludge treatments of 30 or 50 %, significantly correlated to APS input (r = 0.81). This may be explained by the easily available nitrogen as is shown with the positive correlation of CO2 assimilation and leaf nitrogen (r = 0.70). However, a significant reduction in plant growth was observed when treatments of 75 and 100 % of APS were administered, despite a high nutritional level (nitrogen and phosphorus). The study suggests that APS concentrations from 30 to 50 % may positively affect the growth of poplar saplings; however, the higher concentrations indicated a risk for plant growth and the environment.

  15. Sapling biomass allocation and growth in the understory of a deciduous hardwood forest.

    Science.gov (United States)

    Delucia, E; Sipe, T; Herrick, J; Maherali, H

    1998-07-01

    Above- and belowground tissues of co-occurring saplings (0.1-1 m height) of Acer saccharum Marsh. (very shade tolerant), Acer rubrum L. (shade tolerant), Fraxinus americana L. (intermediate shade tolerant), and Prunus serotina Ehrh. (shade intolerant) were harvested from a forest understory to test the hypothesis that the pattern of biomass allocation varied predictably with shade-tolerance rank. The placement and length of branches along the main axis were consistent with the formation of a monolayer of foliage for the tolerant and intermediate species. Other morphological characteristics did not vary predictably with shade-tolerance rank. The maintenance of high specific leaf area (SLA; leaf area/leaf mass) and leaf area ratio (LAR; leaf area/sapling mass) is considered important for growth under extreme shade, yet these traits were not clearly related to the shade-tolerance rank of these species. Fraxinus americana, an intermediate species, had the highest LAR and growth rate in the understory, and with the exception of P. serotina, the very shade-tolerant A. saccharum had the lowest LAR. Prunus serotina maintained a large starch-rich tap root and shoot dieback was common, yielding the largest root/shoot ratio for these species. The observed allocation patterns were not similar to the long-standing expectation for the phenotypic response of juvenile trees to shade, but were consistent with three hypothetical "growth strategies" in the understory: (1) the low SLA and LAR of A. saccharum may provide a measure of defense against herbivores and pathogens and thus promote persistence in the understory, (2) the high SLA for F. americana and high LAR for F. americana and A. rubrum may enable these species to achieve high growth rates in shade, and (3) the large carbohydrate stores of P. serotina may poise this species for opportunistic growth following disturbance. The relative importance of resistance to herbivores and pathogens vs. the maintenance of high growth

  16. Severe Drought Constrains Seedling and Sapling Growth in a Puerto Rican Tropical Rainforest

    Science.gov (United States)

    Alonso-Rodríguez, A. M.; Reed, S.; Cavaleri, M. A.; Uriarte, M.; Carter, K.; Bachelot, B.; Wood, T. E.

    2016-12-01

    Global climate change is expected to cause a significant increase in the frequency and severity of extreme climatic events such as droughts and floods. Nevertheless, the potential impacts of these events are poorly understood for tropical forest ecosystems. For Puerto Rico, 2015 was the 6th driest year on record with below average precipitation from April through September, with peak drought conditions occurring in July. Associated reductions in soil moisture persisted for several months after rain resumed. Given that water availability is known to be an important factor regulating the success of tropical seedlings, we evaluated the effects of this drought on the mortality, growth and species composition of woody understory vegetation in a wet tropical forest in Puerto Rico. Seedlings and saplings were monitored within six 12m2 plots, which are part of a field warming experiment (Tropical Responses to Altered Climate Experiment [TRACE]) designed to warm understory plants and soils by 4°C above ambient temperatures. For this study, all plots were considered replicates since measurements were made during the pre-treatment phase of the experiment. The first census was conducted during the drought (May-June 2015), and the individuals were reassessed in November 2015 and June 2016. Comparisons between the two time periods, drought (Jun2015-Nov2015) and post-drought (Nov2015-Jun2016), revealed significant differences for overall growth rates, which were lower during the drought period, but no differences in mortality, abundance, diversity or species composition. Further analyses were conducted for the most dominant species to elucidate their particular responses to drought and if these responses were related to functional traits. Our results suggest that tropical forest seedlings and saplings may limit their growth during drought conditions, and then quickly recover when conditions return to normal. This relatively rapid recovery suggests that Puerto Rican rainforest

  17. Response of isoprene emission and carbon metabolism to drought in white poplar (Populus alba) saplings.

    Science.gov (United States)

    Brilli, Federico; Barta, Csengele; Fortunati, Alessio; Lerdau, Manuel; Loreto, Francesco; Centritto, Mauro

    2007-01-01

    The mechanism uncoupling isoprene emission and photosynthesis under drought was investigated in Populus alba saplings. Isoprene emission, incorporation of 13C into the isoprene molecule, isoprene synthase (ISPS) activity, concentration and gene expression, and photosynthesis were measured as a function of the fraction of transpirable soil water (FTSW) and in plants recovering from drought. Photosynthesis sharply declined below FTSW30 (a FTSW of 30%) and its inhibition was not caused by metabolic factors. A decline in isoprene emission was only evident towards the FTSW endpoint. 13C incorporation into isoprene was lower when photosynthesis was constrained by drought. ISPS activity was inhibited by mild drought, while ISPS gene expression and concentration declined in concert with isoprene emission at the FTSW endpoint. Following rewatering, isoprene emission was higher than, and photosynthesis was similar to, prestress values. ISPS activity and concentration, and 13C incorporation into isoprene, also rapidly recovered to prestress values, while ISPS gene expression remained low in rewatered plants. Our experiment revealed a larger contribution of alternative carbon sources to isoprene emission only when photosynthesis was dramatically constrained by drought. Isoprene emission was likely controlled at the posttranscriptional level under severe drought.

  18. Trichoderma harzianum Rifai 1295-22 mediates growth promotion of crack willow (Salix fragilis) saplings in both clean and metal-contaminated soil.

    Science.gov (United States)

    Adams, P; De-Leij, F A A M; Lynch, J M

    2007-08-01

    We investigated if the plant growth promoting fungus Trichoderma harzianum Rifai 1295-22 (also known as "T22") could be used to enhance the establishment and growth of crack willow (Salix fragilis) in a soil containing no organic or metal pollutants and in a metal-contaminated soil by comparing this fungus with noninoculated controls and an ectomycorrhizal formulation commercially used to enhance the establishment of tree saplings. Crack willow saplings were grown in a temperature-controlled growth room over a period of 5 weeks' in a garden center topsoil and over 12 weeks in a soil which had been used for disposal of building materials and sewage sludge containing elevated levels of heavy metals including cadmium (30 mg kg(-1)), lead (350 mg kg(-1)), manganese (210 mg kg(-1)), nickel (210 mg kg(-1)), and zinc (1,100 mg kg(-1)). After 5 weeks' growth in clean soil, saplings grown with T. harzianum T22 produced shoots and roots that were 40% longer than those of the controls and shoots that were 20% longer than those of saplings grown with ectomycorrhiza (ECM). T. harzianum T22 saplings produced more than double the dry biomass of controls and more than 50% extra biomass than the ECM-treated saplings. After 12 weeks' growth, saplings grown with T. harzianum T22 in the metal-contaminated soil produced 39% more dry weight biomass and were 16% taller than the noninoculated controls. This is the first report of tree growth stimulation by application of Trichoderma to roots, and is especially important as willow is a major source of wood fuel in the quest for renewable energy. These results also suggest willow trees inoculated with T. harzianum T22 could be used to increase the rate of revegetation and phytostabilization of metal-contaminated sites, a property of the fungus never previously demonstrated.

  19. Diverse patterns of stored water use among saplings in seasonally dry tropical forests.

    Science.gov (United States)

    Wolfe, Brett T; Kursar, Thomas A

    2015-12-01

    Tree species in seasonally dry tropical forests likely vary in their drought-survival mechanisms. Drought-deciduousness, which reduces water loss, and low wood density, which may permit dependence on stored water, are considered key traits. For saplings of six species at two distinct sites, we studied these and two associated traits: the seasonal amount of water released per stem volume ("water released") and the hydraulic capacitance of the stem (C). Two deciduous species with low stem density, Cavanillesia platanifolia and Bursera simaruba, had high C and high dry-season stem water potential (Ψ(stem)), but differed in dry-season water released. C. platanifolia did not use stored water during the dry season whereas B. simaruba, in a drier forest, released stored water. In both, water released was highest while flushing leaves, suggesting that stored water supports leaf flushing. In contrast, two deciduous species with intermediate stem density, Annona hayesii and Genipa americana, had intermediate C, low dry-season Ψ(stem), and high seasonal change in water released. Meanwhile, two evergreen species with intermediate stem density, Cojoba rufescens and Astronium graveolens, had relatively low C, low dry-season Ψ(stem), and intermediate seasonal change in water released. Thus, at least three, distinct stored-water-use strategies were observed. Additionally, bark relative water content (RWC) decreased along with Ψ(stem) during the dry season while xylem RWC did not change, suggesting that bark-stored water buffers Ψ(stem) seasonally. Together these results suggest that seasonal use of stored water and change in Ψ(stem) are associated with functional groups that are characterized by combinations of deciduousness and stem density.

  20. Interspecific variation in compensatory regrowth to herbivory associated with soil nutrients in three Ficus (Moraceae saplings.

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    Jin Zhao

    Full Text Available Plant compensatory regrowth is an induced process that enhances plant tolerance to herbivory. Plant behavior against herbivores differs between species and depends on resource availability, thus making general predictions related to plant compensatory regrowth difficult. To understand how soil nutrients determine the degree of compensatory regrowth for different plant species, we selected saplings of three Ficus species and treated with herbivore insects and artificial injury in both glasshouse conditions and in the field at two soil nutrient levels. Compensatory regrowth was calculated by biomass, relative growth rate and photosynthetic characteristics. A similar pattern was found in both the glasshouse and in the field for species F. hispida, where overcompensatory regrowth was triggered only under fertile conditions, and full compensatory regrowth occurred under infertile conditions. For F. auriculata, overcompensatory regrowth was stimulated only under infertile conditions and full compensatory regrowth occurred under fertile conditions. Ficus racemosa displayed full compensatory regrowth in both soil nutrient levels, but without overcompensatory regrowth following any of the treatments. The three Ficus species differed in biomass allocation following herbivore damage and artificial injury. The root/shoot ratio of F. hispida decreased largely following herbivore damage and artificial injury, while the root/shoot ratio for F. auriculata increased against damage treatments. The increase of shoot and root size for F. hispida and F. auriculata, respectively, appeared to be caused by a significant increase in photosynthesis. The results indicated that shifts in biomass allocation and increased photosynthesis are two of the mechanisms underlying compensatory regrowth. Contrasting patterns among the three Ficus species suggest that further theoretical and empirical work is necessary to better understand the complexity of the plant responses to

  1. Hyperspectral leaf reflectance of Carpinus betulus L. saplings for urban air quality estimation.

    Science.gov (United States)

    Brackx, Melanka; Van Wittenberghe, Shari; Verhelst, Jolien; Scheunders, Paul; Samson, Roeland

    2017-01-01

    In urban areas, the demand for local assessment of air quality is high. The existing monitoring stations cannot fulfill the needs. This study assesses the potential of hyperspectral tree leaf reflectance for monitoring traffic related air pollution. Hereto, 29 Carpinus betulus saplings were exposed to an environment with either high or low traffic intensity. The local air quality was estimated by leaf saturation isothermal remanent magnetization (SIRM). The VIS-NIR leaf reflectance spectrum (350-2500 nm) was measured using a handheld AgriSpec spectroradiometer (ASD Inc.). Secondary, leaf chlorophyll content index (CCI), specific leaf area (SLA) and water content (WC) were determined. To gain insight in the link between leaf reflectance and air quality, the correlation between SIRM and several spectral features was determined. The spectral features that were tested are plain reflectance values, derivative of reflectance, two-band indices using the NDVI formula and PCA components. Spectral reflectance for wavelength bands in the red and short wave IR around the red edge, were correlated to SIRM with Pearson correlations of up to R = -0.85 (R(2) = 0.72). Based on the spectral features and combinations thereof, binomial logistic regression models were trained to classify trees into high or low traffic pollution exposure, with classification accuracies up to 90%. It can be concluded that hyperspectral reflectance of C. betulus leaves can be used to detect different levels of air pollution within an urban environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Retention of stored water enables tropical tree saplings to survive extreme drought conditions.

    Science.gov (United States)

    Wolfe, Brett T

    2017-04-01

    Trees generally maintain a small safety margin between the stem water potential (Ψstem) reached during seasonal droughts and the Ψstem associated with their mortality. This pattern may indicate that species face similar mortality risk during extreme droughts. However, if tree species vary in their ability to regulate Ψstem, then safety margins would poorly predict drought mortality. To explore variation among species in Ψstem regulation, I subjected potted saplings of six tropical tree species to extreme drought and compared their responses with well-watered plants and pretreatment reference plants. In the drought treatment, soil water potential reached Bursera simaruba (L.) Sarg., Cavanillesia platanifolia (Bonpl.) Kunth and Cedrela odorata L. had 100% survival and maintained Ψstem near -1 MPa (i.e., desiccation-avoiding species). Three other species, Cojoba rufescens (Benth.) Britton and Rose, Genipa americana L. and Hymenaea courbaril L. had 50%, 0% and 25% survival, respectively, and survivors had Ψstem <-6 MPa (i.e., desiccation-susceptible species). The desiccation-avoiding species had lower relative water content (RWC) in all organs and tissues (root, stem, bark and xylem) in the drought treatment than in the reference plants (means 72.0-90.4% vs 86.9-97.9%), but the survivors of the desiccation-susceptible C. rufescens had much lower RWC in the drought treatment (44.5-72.1%). Among the reference plants, the desiccation-avoiding species had lower tissue density, leaf-mass fraction and lateral-root surface area (LRA) than the desiccation-susceptible species. Additionally, C. platanifolia and C. odorata had reduced LRA in the drought treatment, which may slow water loss into dry soil. Together, these results suggest that the ability to regulate Ψstem during extreme drought is associated with functional traits that favor retention of stored water and that safety margins during seasonal drought poorly predict survival during extreme drought. © The Author

  3. Spatial distribution of Guaiacum sanctum (Zygophyllaceae seedlings and saplings relative to canopy cover in Palo Verde National Park, Costa Rica

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    Eric J. Fuchs

    2013-09-01

    Full Text Available The spatial distribution of individuals is a fundamental property of most species and constitutes essential information for the development of restoration and conservation strategies, especially for endangered plant species. In this paper we describe the spatial distribution of different size classes of the endangered tropical tree Guaiacum sanctum and the effect of canopy cover on spatial aggregation. Adult G. sanctum were located and mapped in a 50ha plot in Palo Verde National Park, Costa Rica. Seedlings, saplings and juveniles were mapped to the nearest centimetre and permanently marked in three 50x50m subplots. Within each subplot spatial aggregation was assessed using Ripley’s K statistic and canopy opening readings were performed every 5m using a densitometer. Kriging spatial interpolation and Monte Carlo simulations were used to determine if average canopy cover differed among size classes. Individuals of G. sanctum were spatially aggregated at all size classes with seedlings being the most frequent size class in all subplots. Seedlings were found predominantly in areas with significantly higher canopy cover. In contrast, juveniles were more likely found in areas with higher light availability. The high number of seedlings, saplings, and juveniles relative to adults suggests that populations of G. sanctum in PVNP are expanding. Light availability and canopy structure are important factors shaping the spatial distribution of this species. The contemporary demographic structure of G. sanctum is dependent on forest gap dynamics and changes in human disturbance during the past 25 years.

  4. Phenotypic Plasticity Explains Response Patterns of European Beech (Fagus sylvatica L. Saplings to Nitrogen Fertilization and Drought Events

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    Christoph Dziedek

    2017-03-01

    Full Text Available Abstract: Climate and atmospheric changes affect forest ecosystems worldwide, but little is known about the interactive effects of global change drivers on tree growth. In the present study, we analyzed single and combined effects of nitrogen (N fertilization and drought events (D on the growth of European beech (Fagus sylvatica L. saplings in a greenhouse experiment. We quantified morphological and physiological responses to treatments for one‐ and two‐year‐old plants. N fertilization increased the saplings’ aboveground biomass investments, making them more susceptible to D treatments. This was reflected by the highest tissue dieback in combined N and D treatments and a significant N × D interaction for leaf δ13C signatures. Thus, atmospheric N deposition can strengthen the drought sensitivity of beech saplings. One‐year‐old plants reacted more sensitively to D treatments than two‐year‐old plants (indicated by D‐induced shifts in leaf δ13C signatures of one‐year‐old and two‐year‐old plants by +0.5‰ and −0.2‰, respectively, attributable to their higher shoot:root‐ratios (1.8 and 1.2, respectively. In summary, the saplings’ treatment responses were determined by their phenotypic plasticity (shifts in shoot:root‐ratios, which in turn was a function of both the saplings’ age (effects of allometric growth trajectories = apparent plasticity and environmental impacts (effects of N fertilization = plastic allometry.

  5. Effects of flooding duration, -frequency and -depth on the presence of saplings of six woody species in north-west Europe

    NARCIS (Netherlands)

    Vreugdenhil, S.J.; Kramer, K.; Pelsma, T.

    2006-01-01

    Under natural conditions the zonation of woody species in floodplains is to a large extent determined by hydrological conditions. Flood survival varies even among closely related species of the same genus. Most studies that quantify flood survival of seedlings and saplings of European floodplain

  6. INTERACTIONS OF ELEVATED CO2, NH3 AND O-3 ON MYCORRHIZAL INFECTION, GAS-EXCHANGE AND N-METABOLISM IN SAPLINGS OF SCOTS PINE

    NARCIS (Netherlands)

    PEREZSOBA, M; DUECK, TA; PUPPI, G; KUIPER, PJC

    Four-year-old saplings of Scots pine (Pinus sylvestris L.) were exposed for 11 weeks in controlled-environment chambers to charcoal-filtered air, or to charcoal-filtered air supplemented with NH3 (40 mu g m(-3)), O-3 (110 mu g m(-3) during day/ 40 mu g m(-3) during night) or NH3 + O-3. All

  7. Safe for saplings not safe for seeds : Quercus robur recruitment in relation to coarse woody debris in Bialowieza Primeval Forest, Poland

    NARCIS (Netherlands)

    van Ginkel, H.A.L.; Kuijper, D.P.J.; Churski, M.; Zub, K.; Szafranska, P.; Smit, C.

    2013-01-01

    In forested ecosystems, oak saplings can be found in association with coarse woody debris (CWD) that offers protection against herbivore browsing. In this study we investigated whether CWD is already a safe site during the earlier stages of oak recruitment, i.e. at the seed and seedling phase, or

  8. Does long-term cultivation of saplings under elevated CO2 concentration influence their photosynthetic response to temperature?

    Science.gov (United States)

    Šigut, Ladislav; Holišová, Petra; Klem, Karel; Šprtová, Mirka; Calfapietra, Carlo; Marek, Michal V.; Špunda, Vladimír; Urban, Otmar

    2015-01-01

    Background and Aims Plants growing under elevated atmospheric CO2 concentrations often have reduced stomatal conductance and subsequently increased leaf temperature. This study therefore tested the hypothesis that under long-term elevated CO2 the temperature optima of photosynthetic processes will shift towards higher temperatures and the thermostability of the photosynthetic apparatus will increase. Methods The hypothesis was tested for saplings of broadleaved Fagus sylvatica and coniferous Picea abies exposed for 4–5 years to either ambient (AC; 385 µmol mol−1) or elevated (EC; 700 µmol mol−1) CO2 concentrations. Temperature response curves of photosynthetic processes were determined by gas-exchange and chlorophyll fluorescence techniques. Key Results Initial assumptions of reduced light-saturated stomatal conductance and increased leaf temperatures for EC plants were confirmed. Temperature response curves revealed stimulation of light-saturated rates of CO2 assimilation (Amax) and a decline in photorespiration (RL) as a result of EC within a wide temperature range. However, these effects were negligible or reduced at low and high temperatures. Higher temperature optima (Topt) of Amax, Rubisco carboxylation rates (VCmax) and RL were found for EC saplings compared with AC saplings. However, the shifts in Topt of Amax were instantaneous, and disappeared when measured at identical CO2 concentrations. Higher values of Topt at elevated CO2 were attributed particularly to reduced photorespiration and prevailing limitation of photosynthesis by ribulose-1,5-bisphosphate (RuBP) regeneration. Temperature response curves of fluorescence parameters suggested a negligible effect of EC on enhancement of thermostability of photosystem II photochemistry. Conclusions Elevated CO2 instantaneously increases temperature optima of Amax due to reduced photorespiration and limitation of photosynthesis by RuBP regeneration. However, this increase disappears when plants

  9. Drought Effects on Physiology and Biochemistry of Pedunculate Oak (Quercus robur L. and Hornbeam (Carpinus betulus L. Saplings Grown in Urban Area of Novi Sad, Serbia

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    Srđan Stojnić

    2016-06-01

    Full Text Available Background and Purpose: Water stress is one of the major problems for urban trees. It affects a wide range of plant responses, from changes at the cellular level to the reduction in growth rates. Irrigation of trees in urban areas may provide numerous benefits important for increasing tree vitality to withstand other stresses that might occur. The aim of this study was to compare drought effects on some physiological and biochemical performances of Pedunculate oak (Quercus robur L. and Hornbeam (Carpinus betulus L. saplings grown in the urban area. Materials and Methods: The study was conducted during August 2012 at the Boulevard of Europe (Novi Sad, Republic of Serbia. Measurements were carried out on saplings grown in the part of the boulevard with drip irrigation system installed (Site 1 and on the saplings cultivated in the part without any irrigation system (Site 2. Results: Soil moisture content was significantly higher at Site 1 with approximately 57.2%, compared to 18.7% at Site 2. The results showed that irrigated saplings were characterized by significantly higher stomatal conductance in Q. robur and C. betulus. Similarly, the content of free proline, FRAP units and the amount of malonyldialdehyde showed increased values in trees subjected to soil water deficit. In contrast, net photosynthesis, chlorophyll and carotenoid contents did not differ notably in irrigated and non-irrigated Q. robur and C. betulus trees. Conclusions: Water stress significantly affected stomatal conductance and some biochemical properties of Q. robur and C. betulus saplings cultivated at the non-irrigated site. The results showed that the implementation of drip irrigation system in urban landscape is an important tool in the prevention of drought stress effects on the physiological processes of plants.

  10. Growth of olive saplings in different media containing artificial and natural super absorbents at two irrigation intervals

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    A. Mohammadi Torkashvand

    2017-09-01

    Full Text Available A factorial experiment was conducted to evaluate the impact of super absorbents and organic wastes of rice, olive marc, vermicompost and farmyard manure on the soil water holding capacity and the growth of plant based on randomized complete block design with 13 treatments at two irrigation intervals 5 and 10 days. The olive saplings with same heights and better appearances were planted in an open space roofed with a plastic cover with a height of 3 m to avoid the effects of rainfall and snowfall on the results. Stockosorb superabsorbent and weighted zeolite and the rest of bulk materials were mixed. Results showed that the substrate containing 10 g/kg soil of zeolite and the substrate including 20% vermicompost +15% rice wastes +15% manure +50% soil had the best yield and can modify the effect of 10 days irrigation interval compared to the 5 days.

  11. Whole-plant versus leaf-level regulation of photosynthetic responses after partial defoliation in Eucalyptus globulus saplings.

    Science.gov (United States)

    Eyles, Alieta; Pinkard, Elizabeth A; Davies, Noel W; Corkrey, Ross; Churchill, Keith; O'Grady, Anthony P; Sands, Peter; Mohammed, Caroline

    2013-04-01

    Increases in photosynthetic capacity (A1500) after defoliation have been attributed to changes in leaf-level biochemistry, water, and/or nutrient status. The hypothesis that transient photosynthetic responses to partial defoliation are regulated by whole-plant (e.g. source-sink relationships or changes in hydraulic conductance) rather than leaf-level mechanisms is tested here. Temporal variation in leaf-level gas exchange, chemistry, whole-plant soil-to-leaf hydraulic conductance (KP), and aboveground biomass partitioning were determined to evaluate mechanisms responsible for increases in A1500 of Eucalyptus globulus L. potted saplings. A1500 increased in response to debudding (B), partial defoliation (D), and combined B&D treatments by up to 36% at 5 weeks after treatment. Changes in leaf-level factors partly explained increases in A1500 of B and B&D treatments but not for D treatment. By week 5, saplings in B, B&D, and D treatments had similar leaf-specific KP to control trees by maintaining lower midday water potentials and higher transpiration rate per leaf area. Whole-plant source:sink ratios correlated strongly with A1500. Further, unlike KP, temporal changes in source:sink ratios tracked well with those observed for A1500. The results indicate that increases in A1500 after partial defoliation treatments were largely driven by an increased demand for assimilate by developing sinks rather than improvements in whole-plant water relations and changes in leaf-level factors. Three carbohydrates, galactional, stachyose, and, to a lesser extent, raffinose, correlated strongly with photosynthetic capacity, indicating that these sugars may function as signalling molecules in the regulation of longer term defoliation-induced gas exchange responses.

  12. Genotype × herbivore effect on leaf litter decomposition in Betula Pendula saplings: ecological and evolutionary consequences and the role of secondary metabolites.

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    Tarja Silfver

    Full Text Available Plant genetic variation and herbivores can both influence ecosystem functioning by affecting the quantity and quality of leaf litter. Few studies have, however, investigated the effects of herbivore load on litter decomposition at plant genotype level. We reduced insect herbivory using an insecticide on one half of field-grown Betula Pendula saplings of 17 genotypes, representing random intrapopulation genetic variation, and allowed insects to naturally colonize the other half. We hypothesized that due to induced herbivore defence, saplings under natural herbivory produce litter of higher concentrations of secondary metabolites (terpenes and soluble phenolics and have slower litter decomposition rate than saplings under reduced herbivory. We found that leaf damage was 89 and 53% lower in the insecticide treated saplings in the summer and autumn surveys, respectively, which led to 73% higher litter production. Litter decomposition rate was also affected by herbivore load, but the effect varied from positive to negative among genotypes and added up to an insignificant net effect at the population level. In contrast to our hypothesis, concentrations of terpenes and soluble phenolics were higher under reduced than natural herbivory. Those genotypes, whose leaves were most injured by herbivores, produced litter of lowest mass loss, but unlike we expected, the concentrations of terpenes and soluble phenolics were not linked to either leaf damage or litter decomposition. Our results show that (1 the genetic and herbivore effects on B. pendula litter decomposition are not mediated through variation in terpene or soluble phenolic concentrations and suggest that (2 the presumably higher insect herbivore pressure in the future warmer climate will not, at the ecological time scale, affect the mean decomposition rate in genetically diverse B. pendula populations. However, (3 due to the significant genetic variation in the response of decomposition to

  13. Long-term fertilization determines different metabolomic profiles and responses in saplings of three rainforest tree species with different adult canopy position.

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    Albert Gargallo-Garriga

    Full Text Available Tropical rainforests are frequently limited by soil nutrient availability. However, the response of the metabolic phenotypic plasticity of trees to an increase of soil nutrient availabilities is poorly understood. We expected that increases in the ability of a nutrient that limits some plant processes should be detected by corresponding changes in plant metabolome profile related to such processes.We studied the foliar metabolome of saplings of three abundant tree species in a 15 year field NPK fertilization experiment in a Panamanian rainforest. The largest differences were among species and explained 75% of overall metabolome variation. The saplings of the large canopy species, Tetragastris panamensis, had the lowest concentrations of all identified amino acids and the highest concentrations of most identified secondary compounds. The saplings of the "mid canopy" species, Alseis blackiana, had the highest concentrations of amino acids coming from the biosynthesis pathways of glycerate-3P, oxaloacetate and α-ketoglutarate, and the saplings of the low canopy species, Heisteria concinna, had the highest concentrations of amino acids coming from the pyruvate synthesis pathways.The changes in metabolome provided strong evidence that different nutrients limit different species in different ways. With increasing P availability, the two canopy species shifted their metabolome towards larger investment in protection mechanisms, whereas with increasing N availability, the sub-canopy species increased its primary metabolism. The results highlighted the proportional distinct use of different nutrients by different species and the resulting different metabolome profiles in this high diversity community are consistent with the ecological niche theory.

  14. Nitrogen fixation in lysimeter-grown grey alder (Alnus incana (L.) Moench.) saplings - influence of nitrogen fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Ericsson, Tom; Rytter, L.

    1998-07-01

    A lysimeter study was started in order to test if nitrogen fixation as well as biomass production in grey alder plantations (Alnus incana (L.) Moench.) can be stimulated by daily addition of small N doses. One-year-old grey alder saplings were planted in undrained lysimeters, each filled with 200 litres of quartz sand. Water and a low-concentrated balanced nutrient solution were distributed daily via a drip irrigation system. In this paper a complete N budget for the first growing season is presented. The results showed that presence of mineral N in the growth substrate had no beneficial effect on growth during the first growing season. The capacity of the plants to make use of the daily N additions was overestimated in this investigation. Almost twice as much N was added with fertilizers as the amount of N accumulating in the tissues. Consequently, the N concentration in the drainage water increased and the annual rate of N{sub 2}-fixation was strongly suppressed, 31 mg N plant{sup -1} (1 kg N ha{sup -1}) versus 1700 mg N plant{sup -1} (32 kg N ha{sup -1}) in the controls. However, no harmful effect of the elevated soil-N concentration on nodule development could be detected.

  15. Transposition of Alchornea castaneifolia (Willd. A. Juss. Seedlings from natural regeneration as a strategy for saplings production in nursery

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    Sheilly Raquelly Prado de Paula

    2013-06-01

    Full Text Available Alchornea castaneifolia (Willd. A. Juss. (Urana is a native species with potential for restoration of riparian vegetation and urban forestry. Given the difficulty of its propagation and the lack of knowledge about their behavior in nursery, this study aimed to evaluate the transposition of Alchornea castaneifolia from natural regeneration as a strategy for saplings production in nursery. The collecting took place in Porto Acre – AC, and selected 120 seedlings, which were divided into three height classes (15 cm and cultivated in four substrates (soil, sand, wasting açaí+soil, Plantmax in a completely randomized design in a 3x4 factorial design. We investigated the survival of seedlings and the growth in sand substrate to the characteristics height (H and collar diameter (DC, the relationship H/DC, dry mass of shoots, roots and total between the three height classes of the seedlings. The highest percentage of Alchornea castaneifolia seedlings survival was observed in the sand substrate (67%, followed by the wasting açaí+soil substrate (43%. Seedlings that showed greater growth in height, collar diameter and dry mass production were contained in the class above 15 cm in sand substrate. However, the 10-15 cm class of height presented 100% survival of seedlings in sand substrate and also provided high growth. It is therefore recommended the transposition of seedling in the 10-15 cm class using sand substrate for the propagation of Alchornea castaneifolia in nursery.

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

    Science.gov (United States)

    Wein, Annika; Bauhus, Jürgen; Bilodeau-Gauthier, Simon; Scherer-Lorenzen, Michael; Nock, Charles; Staab, Michael

    2016-01-01

    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.

  17. Low among-provenance differences in structural and functional plasticity in response to nutrients in saplings of the circum-Mediterranean tree Arbutus unedo L.

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    Santiso, Xabier; Retuerto, Rubén

    2015-10-01

    The Mediterranean region is an area of special interest for conservation where the incidence of multiple drivers of global change is expected to increase. One of the factors predicted to change is soil-nutrient availability, an essential factor for plant growth. Thus, study of the effects of variation in this parameter is especially relevant in species with a circum-Mediterranean distribution, such as Arbutus unedo L., in which the different provenances grow in different habitats, which must differ in nutritional conditions. We aimed to determine the effect of provenance on plasticity, to establish whether structural and morphological traits differ in the level of plasticity and to assess how nutrients affect the photosynthetic light response. In a common garden experiment, we studied seven provenances from the circum-Mediterranean range of A. unedo and established two nutrient treatments (low and high nutrient availability). We measured physiological and structural traits in 1-year-old sapling and determined a phenotypic plasticity index (PPI) to quantify the level of plasticity, whereas the radiation effects were tested by construction and analysis of light response curves. Interestingly, provenance did not explain a significant amount of variance, but the plasticity was four times higher for the structural traits than for the physiological traits. Therefore, the plasticity to nutrient availability will not favour or prevent the expansion or contraction of the range of any of these provenances of A. unedo. Furthermore, the structural plasticity demonstrated the ability of the strawberry tree to optimize resource allocation, whereas the physiology remained stable, thus avoiding extra expenditure. The study findings also suggest that increased availability of nutrients would improve the performance of the species during the Mediterranean summer, characterized by high irradiance. These abilities will be key to the survival of saplings of the species under the future

  18. Sapling growth as a function of light and landscape-level variation in soil water and foliar nitrogen in Northern Michigan.

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    Kobe, Richard K

    2006-02-01

    Interspecific differences in sapling growth responses to soil resources could influence species distributions across soil resource gradients. I calibrated models of radial growth as a function of light intensity and landscape-level variation in soil water and foliar N for saplings of four canopy tree species, which differ in adult distributions across soil resource gradients. Model formulations, characterizing different resource effects and modes of influencing growth, were compared based on relative empirical support using Akaike's Information Criterion. Contrary to expectation, the radial growth of species associated with lower fertility (Acer rubrum and Quercus rubra) was more sensitive to variation in soil resources than the high fertility species Acer saccharum. Moreover, there was no species tradeoff between growth under high foliar N versus growth under low foliar N, which would be expected if growth responses to foliar N mediated distributions. In general, there was functional consistency among species in growth responses to light, foliar N, and soil water availability, respectively. Foliar N influenced primarily high-light growth in F. grandifolia, A. rubrum, and Q. rubra (but was not significant for A. saccharum). In A. saccharum and A. rubrum, for which soil water availability was a significant predictor, soil water and light availability simultaneously limited growth (i.e., either higher light or water increased growth). Simple resource-based models explained 0.74-0.90 of growth variance, indicating a high degree of determinism. Results suggest that nitrogen effects on forest dynamics would be strongest in high-light early successional communities but that water availability influences growth in both early successional and understory environments.

  19. Recovery of Physiological Traits in Saplings of Invasive Bischofia Tree Compared with Three Species Native to the Bonin Islands under Successive Drought and Irrigation Cycles.

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    Kenichi Yazaki

    Full Text Available Partial leaf shedding induced by hydraulic failure under prolonged drought can prevent excess water consumption, resulting in delayed recovery of carbon productivity following rainfall. To understand the manner of water use of invasive species in oceanic island forests under a fluctuating water regime, leaf shedding, multiple physiological traits, and the progress of embolism in the stem xylem under repeated drought-irrigation cycles were examined in the potted saplings of an invasive species, Bischofia javanica Blume, and three endemic native species, Schima mertensiana (Sieb. Et Zucc, Koitz., Hibiscus glaber Matsum, and Distylium lepidotum Nakai, from the Bonin Islands, Japan. The progress of xylem embolism was observed by cryo-scanning electron microscopy. The samples exhibited different processes of water saving and drought tolerance based on the different combinations of partial leaf shedding involved in embolized conduits following repeated de-rehydration. Predawn leaf water potential largely decreased with each successive drought-irrigation cycle for all tree species, except for B. javanica. B. javanica shed leaves conspicuously under drought and showed responsive stomatal conductance to VPD, which contributed to recover leaf gas exchange in the remaining leaves, following a restored water supply. In contrast, native tree species did not completely recover photosynthetic rates during the repeated drought-irrigation cycles. H. glaber and D. lepidotum preserved water in vessels and adjusted leaf osmotic rates but did not actively shed leaves. S. mertensiana exhibited partial leaf shedding during the first cycle with an osmotic adjustment, but they showed less responsive stomatal conductance to VPD. Our data indicate that invasive B. javanica saplings can effectively use water supplied suddenly under drought conditions. We predict that fluctuating precipitation in the future may change tree distributions even in mesic or moist sites in the

  20. The harsh life of an urban tree: the effect of a single pulse of ozone in salt-stressed Quercus ilex saplings.

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    Guidi, Lucia; Remorini, Damiano; Cotrozzi, Lorenzo; Giordani, Tommaso; Lorenzini, Giacomo; Massai, Rossano; Nali, Cristina; Natali, Lucia; Pellegrini, Elisa; Trivellini, Alice; Vangelisti, Alberto; Vernieri, Paolo; Landi, Marco

    2017-02-01

    Ozone (O3) and salinity are usually tested as combined factors on plant performance. However, the response to a single episode of O3 in plants already stressed by an excess of NaCl as occurs in the natural environment has never been investigated, but is important given that it is commonly experienced in Mediterranean areas. Three-year-old Quercus ilex L. (holm oak) saplings were exposed to salinity (150 mM NaCl, 15 days), and the effect on photosynthesis, hydric relations and ion partitioning was evaluated (Experiment I). In Experiment II, salt-treated saplings were exposed to 80 nl l-1 of O3 for 5 h, which is a realistic dose in a Mediterranean environment. Gas exchanges, chlorophyll fluorescence and antioxidant systems were characterized to test whether the salt-induced stomatal closure limited O3 uptake and stress or whether the pollutant represents an additional stressor for plants. Salt-dependent stomatal closure depressed the photosynthetic process (-71.6% of light-saturated rate of photosynthesis (A380)) and strongly enhanced the dissipation of energy via the xanthophyll cycle. However, salt-treated plants had higher values of net assimilation rate/stomatal conductance (A/gs) than the controls, which was attributable to a greater mesophyll conductance gm/gs and carboxylation efficiency (higher gm/maximal rate of Rubisco carboxylation (Vcmax)), thus suggesting no damage to chloroplasts. O3 did not exacerbate the effect of salinity on photosynthesis, however a general enhancement of the Halliwell-Asada cycle was necessary to counteract the O3-triggered oxidative stress. Despite the 79.4% gs reduction in salt-stressed plants, which strongly limited the O3 uptake, a single peak in the air pollutant led to an additional burden for the antioxidant system when plants had been previously subjected to salinity. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Acclimation of fine root respiration to soil warming involves starch deposition in very fine and fine roots: a case study in Fagus sylvatica saplings.

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    Di Iorio, Antonino; Giacomuzzi, Valentino; Chiatante, Donato

    2016-03-01

    Root activities in terms of respiration and non-structural carbohydrates (NSC) storage and mobilization have been suggested as major physiological roles in fine root lifespan. As more frequent heat waves and drought periods within the next decades are expected, to what extent does thermal acclimation in fine roots represent a mechanism to cope with such upcoming climatic conditions? In this study, the possible changes in very fine (diameter Fagus sylvatica saplings subjected to a simulated long-lasting heat wave event and to co-occurring soil drying. For both very fine and fine roots, soil temperature (ST) resulted inversely correlated with specific root length, respiration rates and SSs concentration, but directly correlated with root mass, root tissue density and starch concentration. In particular, starch concentration increased under 28 °C for successively decreasing under 21 °C ST. These findings showed that thermal acclimation in very fine and fine roots due to 24 days exposure to high ST (∼ 28 °C), induced starch accumulation. Such 'carbon-savings strategy' should bear the maintenance costs associated to the recovery process in case of restored favorable environmental conditions, such as those occurring at the end of a heat wave event. Drought condition seems to affect the fine root vitality much more under moderate than high temperature condition, making the temporary exposure to high ST less threatening to root vitality than expected. © 2015 Scandinavian Plant Physiology Society.

  2. Changes in the dynamics of foliar N metabolites in oak saplings by drought and air warming depend on species and soil type.

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    Bin Hu

    Full Text Available Climate change poses direct or indirect influences on physiological mechanisms in plants. In particular, long living plants like trees have to cope with the predicted climate changes (i.e. drought and air warming during their life span. The present study aimed to quantify the consequences of simulated climate change for foliar N metabolites over a drought-rewetting-drought course. Saplings of three Central European oak species (i.e. Quercus robur, Q. petraea, Q. pubescens were tested on two different soil types (i.e. acidic and calcareous. Consecutive drought periods increased foliar amino acid-N and soluble protein-N concentrations at the expense of structural N in all three oak species. In addition, transient effects on foliar metabolite dynamics were observed over the drought-rewetting-drought course. The lowest levels of foliar soluble protein-N, amino acid-N and potassium cation with a minor response to drought and air warming were found in the oak species originating from the driest/warmest habitat (Q. pubescens compared to Q. robur and Q. petraea. Higher foliar osmolyte-N and potassium under drought and air warming were observed in all oak species when grown on calcareous versus acidic soil. These results indicate that species-specific differences in physiological mechanisms to compensate drought and elevated temperature are modified by soil acidity.

  3. Different sensitivity of isoprene emission, respiration and photosynthesis to high growth temperature coupled with drought stress in black poplar (Populus nigra) saplings.

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    Centritto, Mauro; Brilli, Federico; Fodale, Roberta; Loreto, Francesco

    2011-03-01

    The effects of the interaction between high growth temperatures and water stress on gas-exchange properties of Populus nigra saplings were investigated. Water stress was expressed as a function of soil water content (SWC) or fraction of transpirable soil water (FTSW). Isoprene emission and photosynthesis (A) did not acclimate in response to elevated temperature, whereas dark (R(n)) and light (R(d)) respiration underwent thermal acclimation. R(d) was ~30% lower than R(n) irrespective of growth temperature and water stress level. Water stress induced a sharp decline, but not a complete inhibition, of both R(n) and R(d). There was no significant effect of high growth temperature on the responses of A, stomatal conductance (g(s)), isoprene emission, R(n) or R(d) to FTSW. High growth temperature resulted in a significant increase in the SWC endpoint. Photosynthesis was limited mainly by CO(2) acquisition in water-stressed plants. Impaired carbon metabolism became apparent only at the FTSW endpoint. Photosynthesis was restored in about a week following rewatering, indicating transient biochemical limitations. The kinetics of isoprene emission in response to FTSW confirmed that water stress uncouples the emission of isoprene from A, isoprene emission being unaffected by decreasing g(s). The different kinetics of A, respiration and isoprene emission in response to the interaction between high temperature and water stress led to rising R(d)/A ratio and amount of carbon lost as isoprene. Since respiration and isoprene sensitivity are much lower than A sensitivity to water stress, temperature interactions with water stress may dominate poplar acclimatory capability and maintenance of carbon homeostasis under climate change scenarios. Furthermore, predicted temperature increases in arid environments may reduce the amount of soil water that can be extracted before plant gas exchange decreases, exacerbating the effects of water stress even if soil water availability is not

  4. Variation in leaf and twig CO2 flux as a function of plant size: a comparison of seedlings, saplings and trees.

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    Sendall, Kerrie M; Reich, Peter B

    2013-07-01

    Rates of tissue-level function have been hypothesized to decline as trees grow older and larger, but relevant evidence to assess such changes remains limited, especially across a wide range of sizes from saplings to large trees. We measured functional traits of leaves and twigs of three cold-temperate deciduous tree species in Minnesota, USA, to assess how these vary with tree height. Individuals ranging from 0.13 to 20 m in height were sampled in both relatively open and closed canopy environments to minimize light differences as a potential driver of size-related differences in leaf and twig properties. We hypothesized that (H1) gas-exchange rates, tissue N concentration and leaf mass per unit area (LMA) would vary with tree size in a pattern reflecting declining function in taller trees, yet maintaining (H2) bivariate trait relations, common among species as characterized by the leaf economics spectrum. Taking these two ideas together yielded a third, integrated hypothesis that (H3) nitrogen (N) content and gas-exchange rates should decrease monotonically with tree size and LMA should increase. We observed increasing LMA and decreasing leaf and twig Rd with increasing size, which matched predictions from H1 and H3. However, opposite to our predictions, leaf and twig N generally increased with size, and thus had inverse relations with respiration, rather than the predicted positive relations. Two exceptions were area-based leaf N of Prunus serotina Ehrh. in gaps and mass-based leaf N of Quercus ellipsoidalis E. J. Hill in gaps, both of which showed qualitatively hump-shaped patterns. Finally, we observed hump-shaped relationships between photosynthetic capacity and tree height, not mirroring any of the other traits, except in the two cases highlighted above. Bivariate trait relations were weak intra-specifically, but were generally significant and positive for area-based traits using the pooled dataset. Results suggest that different traits vary with tree size in

  5. Leaf traits and photosynthetic responses of Betula pendula saplings to a range of ground-level ozone concentrations at a range of nitrogen loads.

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    Harmens, Harry; Hayes, Felicity; Sharps, Katrina; Mills, Gina; Calatayud, Vicent

    2017-04-01

    Ground-level ozone (O3) concentrations and atmospheric nitrogen (N) deposition rates have increased strongly since the 1950s. Rising ground-level O3 concentrations and atmospheric N deposition both affect plant physiology and growth, however, impacts have often been studied in isolation rather than in combination. In addition, studies are often limited to a control treatment and one or two elevated levels of ozone and/or nitrogen supply. In the current study, three-year old Betula pendula saplings were exposed to seven different O3 profiles (24h mean O3 concentration of 36-68ppb in 2013, with peaks up to an average of 105ppb) in precision-controlled hemispherical glasshouses (solardomes) and four different N loads (10, 30, 50 or 70kgNha-1y-1) in 2012 and 2013. Here we report on the effects of enhanced O3 concentrations and N load on leaf traits and gas exchange in leaves of varying age and developmental stage in 2013. The response of leaf traits to O3 (but not N) vary with leaf developmental stage. For example, elevated O3 did not affect the chlorophyll content of the youngest fully expanded leaf, but it reduced the chlorophyll content and photosynthetic parameters in aging leaves, relatively more so later than earlier in the growing season. Elevated O3 enhanced the N content of senesced leaves prior to leaf fall, potentially affecting subsequent N cycling in the soil. Enhanced N generally stimulated the chlorophyll content and photosynthetic capacity. Whilst elevated O3 reduced the light-saturated rate of photosynthesis (Asat) in aging leaves, it did not affect stomatal conductance (gs). This suggests that photosynthesis and gs are not closely coupled at elevated O3 under-light saturating conditions. We did not observe any interactions between O3 and N regarding photosynthetic parameters (Vc,max, Jmax, Asat), chlorophyll content, gs, N content in senesced leaves and leaf number. Hence, the sensitivity of these leaf traits to O3 in young silver birch trees is

  6. Genetic diversity in rosewood saplings (Aniba rosaeodora ducke, Lauraceae: an ecological approach Diversidade genética em plantas jovens de Pau-rosa (Aniba rosaeodora Ducke, Lauraceae: uma abordagem ecológica

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    Ronaldo Pereira Santos

    2008-12-01

    Full Text Available This article takes an ecological approach to the genetic diversity of Rosewood (Aniba rosaeodora Ducke in a central Amazonian terra firme forest north of Manaus. Planted Rosewood setting, under partial shaded canopy, were assessed in terms of fruiting production, frugivory, and seed dispersal. Using RAPD molecular analysis procedures, the influence of the spatial distribution of adult trees on the genetic diversity (polymorphism of saplings was assessed with genetic samples from 34 reproductive trees and 60 saplings. The density and distribution patterns the reproductive trees did not modify the sapling"s diversity (1.86%, AMOVA. Two types of adult tree dispersion were identified; i clumped and ii more widely dispersed. Polymorphism (77.5% and gene flow were high between these. Although more sapling genetic variability in areas with a higher density of mature plants was not as high as expected, density did not affect the genetic diversity of samplings, indicating a high incidence of gene flow amongst trees. In planted Rosewood population (surrounded by low disturbed forest, fruiting trees experienced a high level of removal of seeds by toucans (Rhamphastidae, about of 50%. The high gene flow found among native trees suggested that toucans, promoting seed rain at short and long distances from maternal trees, actively contribute to the maintenance of genetic diversity within wild rosewood populations.Dados genéticos e ecológicos foram obtidos do Pau-rosa (Aniba rosaeodora Ducke em uma floresta de terra firme localizada ao norte de Manaus. Em um sistema de plantio composto de plantas sob sombreamento parcial, foram analisados dados de frugivoria, produção de frutos e dispersão. Numa população natural, com 34 plantas adultas e 60 jovens, foi analisada a influência da distribuição espacial das plantas adultas na diversidade genética (polimorfismo das jovens utilizando o marcador molecular RAPD. O modelo de distribuição e densidade das

  7. Effects of Long-Term Periodic Submergence on Photosynthesis and Growth of Taxodium distichum and Taxodium ascendens Saplings in the Hydro-Fluctuation Zone of the Three Gorges Reservoir of China.

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    Wang, Chaoying; Li, Changxiao; Wei, Hong; Xie, Yingzan; Han, Wenjiao

    2016-01-01

    Responses of bald cypress (Taxodium distichum) and pond cypress (Taxodium ascendens) saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR) were studied. Water treatments of periodic deep submergence (DS) and moderate submergence (MS) in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles) compared to a control (i.e. shallow submergence, abbreviated as SS). Results showed that pond cypress had no significant change in net photosynthetic rate (Pn) in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH) and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall.

  8. Effects of Long-Term Periodic Submergence on Photosynthesis and Growth of Taxodium distichum and Taxodium ascendens Saplings in the Hydro-Fluctuation Zone of the Three Gorges Reservoir of China.

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    Chaoying Wang

    Full Text Available Responses of bald cypress (Taxodium distichum and pond cypress (Taxodium ascendens saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR were studied. Water treatments of periodic deep submergence (DS and moderate submergence (MS in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles compared to a control (i.e. shallow submergence, abbreviated as SS. Results showed that pond cypress had no significant change in net photosynthetic rate (Pn in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall.

  9. Sobrevivência em viveiro de mudas de espécies nativas retiradas da regeneração natural de remanescente florestal Survival in nursery of native species saplings obtained from natural regeneration of forest fragments

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    Ricardo Augusto Gorne Viani

    2007-08-01

    Full Text Available O objetivo deste trabalho foi avaliar a sobrevivência em viveiro de plântulas retiradas da regeneração natural de remanescente de Floresta Estacional Semidecidual, localizado em Bofete, SP. Indivíduos com até 30 cm de espécies arbustivo-arbóreos foram coletados em parcelas instaladas previamente em remanescente florestal, transplantados para viveiro sob sombrite 50%, e avaliados periodicamente durante nove meses. Ao todo foram transferidos para o viveiro 2.424 indivíduos, pertencentes a 110 espécies. A taxa média de sobrevivência foi de 69%, com variação nos resultados para as diferentes espécies, famílias e classes de altura dos indivíduos. Embora espécies pioneiras tenham apresentado taxa de sobrevivência significativamente maior que não pioneiras, várias espécies não pioneiras apresentaram elevada taxa de sobrevivência. Muitas das espécies sobreviventes não são encontradas nos viveiros florestais do Estado de São Paulo. A produção de mudas por meio da transferência da regeneração natural de áreas naturais é uma estratégia complementar viável, que eleva a riqueza de espécies dos viveiros florestais.Seedling survival was evaluated regarding transplanted saplings obtained from natural regeneration of a Semideciduous Seasonal Forest fragment, located at Bofete, São Paulo State, Brazil. Shrub and trees species seedlings up to 30 cm height were collected from samples sited on a forest remnant, transplanted to a nursery under 50% shade tissue, and evaluated periodically during nine months. A total of 2,424 seedlings, belonging to 110 species were transferred to the nursery. Average survival reached 69%, although this survival rate was quite variable according to the species, families and height classes of the evaluated individuals. In spite of the fact that pioneer species presented higher survival rate, several non-pioneer species also obtained high values of survival. Besides, many of the survivor species are

  10. Aspectos morfológicos de frutos, sementes e desenvolvimento de plântulas e plantas jovens de Unonopsis lindmanii Fries (Annonaceae Morphological aspects of fruits, seeds, and seedling and sapling development of Unonopsis lindmanii Fries (Annonaceae

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    Joanice Lube Battilani

    2007-12-01

    Full Text Available Unonopsis lindmanii é uma arvoreta, perene, restrita às formações ciliares do Brasil Central. Este estudo descreve os aspectos morfológicos dos frutos, sementes e desenvolvimento das formas juvenis da espécie. Os frutos são apocárpicos, múltiplos, livres entre si, carnosos, indeiscentes e as sementes possuem forma discóide, coloração marrom escura, tegumento ornamentado de aspecto rugoso. A germinação é lenta, irregular e muito baixa em câmara de germinação (3% e alta em viveiro de mudas (70% sugerindo fotoperiodismo positivo. A plântula é do tipo criptocotiledonar-epígea. As plantas jovens apresentam folhas simples, alternas, com pecíolos curtos, simétricas, membranáceas de forma elíptica. O padrão de venação é do tipo camptódromo-broquidódromo. Estes resultados permitem identificação da espécie no campo, o que pode auxiliar em estudos de descrições de comunidades e por serem dispersas por aves, consiste em excelente opção para utilização em projetos de restauração de áreas degradadas.Unonopsis lindmanii is a small tree restricted to riparian forests in Central Brazil. Here we describe the morphological characteristics of the fruits and seeds, and the development of seedlings. The multiple, indehiscent fruits are apocarpous, unattached to one another, with a fleshy pericarp, and the seeds are darkish brown and discoid in shape, with an ornamented, rugose tegument. Germination is slow and irregular, and rates are very low in the germination chamber (3%. They are high in the greenhouse (70% suggesting positive photoperiodism. Initial seedling morphology is cryptocotyledonar-epigeous. Saplings have simple, alternate leaves with short petioles, and are symmetric, membranous, and elliptical. The venation pattern is of the brochidodrome-camptodrome type. These results help to identify the species in the field, and may also contribute to community description studies. Because it is dispersed by birds, this

  11. Morfologia foliar de indivíduos jovens e adultos de Caesalpinia echinata Lam. numa floresta semidecídua do Sul da Bahia Leaf morphology of saplings and adult individuals of Caesalpinia echinata Lam. in a semidecidual forest of Southern Bahia, Brazil

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    Maria Cristina Sanches

    2009-10-01

    Full Text Available Caesalpinia echinata Lam. (Caesalpiniaceae é uma espécie arbórea que ocorre naturalmente no interior da floresta e atinge os estratos superiores do dossel por meio de pequenas clareiras. Objetivou-se, neste estudo, comparar alguns aspectos da morfologia foliar entre indivíduos adultos, cujas folhas se encontravam em pleno sol e jovens no sub-bosque. O estudo foi realizado numa floresta semidecídua, localizada no Município de Jussari, Bahia. Inicialmente, foram localizados e marcados oito indivíduos adultos e oito jovens para cada adulto. Foram coletadas e analisadas oito folhas para cada adulto e três para cada jovem, em duas épocas (setembro/novembro de 2004 e abril de 2005. Em geral, as áreas das folhas, das ráquis e dos folíolos, o comprimento das ráquis, a largura das folhas, o número de pinas e a massa seca das folhas foram significativamente superiores nos indivíduos jovens, ao passo que as massas específicas das folhas e dos folíolos foram significativamente superiores nos indivíduos adultos. Tanto nos adultos quanto nos jovens, nas duas épocas de coleta foram verificadas relações altamente significativas entre a massa seca e a área das folhas. Os resultados indicaram que folhas de C. echinata apresentam características que maximizam a absorção de luz onde este recurso é limitante e, ao mesmo tempo, direcionam maior alocação de carbono para os tecidos de suporte. Tais resultados estão de acordo com o observado no estádio sucessional da espécie analisada e com a sua estratégia de ocupação dos espaços gerados pela formação de pequenas clareiras, em ambiente de mata semidecídua.Caesalpinia echinata Lam. (Caesalpiniaceae is a tree species that naturally regenerates in the forest understory and reaches the upper canopy through small gaps. We conducted a study with the objective of comparing some aspects of leaf morphology of adult individuals, in which the leaves were exposed to full sunlight, and saplings

  12. Relationships between Prosopis flexuosa (Fabaceae and cattle in the Monte desert: Seeds, seedlings and saplings on cattle-use site classes Interacciones entre Prosopis flexuosa (Fabaceae y el ganado en el desierto de Monte: Semillas, plántulas y renovales en los sitios de uso del ganado

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    CLAUDIA M CAMPOS

    2011-06-01

    Full Text Available The fate of Prosopis flexuosa seeds dispersed by cattle is dependant on the spatial pattern of dung deposition and foraging movements. We hypothesised that cattle-use site classes explain the response variables related to seed input and fate of seeds, seedlings and saplings (small plants more than one year old. We defined sites with heavy cattle traffic ("trails" and "periphery of trails", sites used for resting and foraging ("under Prosopis", and sites where isolated individuals only walk ("under shrubs" and "bare soil". Considering the established cattle-use site classes, our specific goals were to quantify and compare: (1 seeds transported in cattle dung; (2 seedlings 10 months after dung deposition; (3 established saplings; and (4 germinated and remaining seeds, and seedling survival in dung immediately after dung deposition. In a grazed field at Ñacuñán (Mendoza, Argentina we worked in four similar areas, each consisting of 25-ha plots 2 km apart. Space use by cattle caused differential seed input: "under Prosopis" and in the "periphery of trails" animals deposited the largest amounts of dung and seeds. Ten months after dung deposition, the highest number of seedlings occurred on "trails", "under Prosopis" and in the "periphery of trails". In the long term, the highest number of established saplings occurred only in the "periphery of trails". The number of seeds germinated immediately after fruit production and dung deposition was very low. Survival of seedlings sprouting from dung-germinated seeds did not exceed one week. On "trails" and in the "periphery of trails" the persistence of seeds in dung was low because of dung disintegration by the action of cattle trampling. The seeds that did not remain in dung were probably the source of seeds that will germinate in the next wet season (i.e. 10 months after dung deposition. With different effects depending on cattle site activity and on the stage of the P. flexuosa plant (seed, seedling

  13. Light-related variation in sapling architecture of three shade-tolerant tree species of the Mexican rain forest Variación arquitectural de árboles juveniles en relación con la luz en tres especies tolerantes a la sombra en una selva húmeda mexicana

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    JOSÉ LUIS MARTÍNEZ-SÁNCHEZ

    2008-09-01

    Full Text Available The crown architecture of three shade-tolerant tree species (two subcanopy and one mid-canopy was analyzed in relation to the light regime of the forest understorey. The aim was to examine to which extent shade-tolerant species variate in their crown architecture. Tree saplings (265 between 50 and 300 cm height, and distributed from understorey to variously-sized canopy gaps, were measured for 13 architectural traits in the lowland rain forest of Los Tuxtlas, México. The analysis showed that the three species changed their architecture as light increased but in a different way. No species conformed to the typical wide-crown type expected for shade-tolerant species, and in contrast they presented some traits of light demanding species. The two sub-canopy species tended to adopt a crown form between a narrow- and wide-crown type, and the mid-canopy species showed more traits of a narrow-crown type. The horizontal crown area appeared as the more related trait to the light and sapling height. It is concluded that despite being shade-tolerant, the studied species make use of better-lit environments in the forest understorey. The crown architecture of shade-tolerant species is not as rigid as originally conceived.Se analizó la arquitectura de la copa de tres especies tolerantes a la sombra (dos del sotobosque y una del dosel medio en relación con el ambiente lumínico del sotobosque de la selva. El objetivo fue examinar el grado de variación que presenta la arquitectura de la copa de especies tolerantes a la sombra. Para esto, se midieron 13 variables arquitecturales en 265 árboles juveniles (50-300 cm de altura distribuidos desde sitios de selva madura hasta claros de diversos tamaños, en la selva húmeda tropical de Los Tuxtlas, México. El análisis mostró que las tres especies cambian la arquitectura de su copa a medida que aumenta la disponibilidad de luz, pero de diferente forma. Ninguna especie presentó el típico modelo de copa plana

  14. Shading and root-shoot relations in saplings of silver birch, pedunculate oak and beech

    NARCIS (Netherlands)

    Hees, van A.F.M.; Clerkx, A.P.P.M.

    2003-01-01

    Silver birch (Betula pendula Roth), pedunculate oak (Quercus robur L.) and beech (Fagus sylvatica L.) can regenerate successfully under a canopy of Scots pine (Pinus sylvestris L.). Shading reduces plant growth and modifies plant form, two related aspects. This study focuses on the effects of

  15. REARING EFFICIENCY AND NUTRITIONAL QUALITY ASSESSMENT FOR CARP SAPLING (CYPRINUS CARPIO LINNE, 1758 FROM RECIRCULATING SYSTEMS

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    ELPIDA PALTENEA

    2008-10-01

    Full Text Available Common carp, Cyprinus carpio L. of 8 months older, rearing in recirculation system during 107 days period - he has been analysed from the point of view of feeding efficiency and nutritional quality of carp carcass. The stocking of breeding ponds has been made at 12.17 kg/m3 density, the initial average weight of fishes has been 82.2 g/ex., biochemical composition of carp carcass has been following: protein 14.35%, fat 1.10%, ash 1.67% and moisture 82.22%. Weekly, there has been analysed biochemical composition of meat and protein efficiency coefficient (PER, protein using efficiency (PUE, retained protein (RP. The nutritional quality of fish meat and appreciation coefficients of fish rearing they indicate a good capitalization of delivered food.

  16. Variation in performance of beech saplings of 7 European provenances under shade and full light conditions

    NARCIS (Netherlands)

    Kramer, K.; Hees, van A.F.M.; Jans, W.W.P.

    2001-01-01

    The use of beech seedlings from South-East European and North-West (NW) provenances for underplanting in coniferous forests in North-West Europe was investigated by means of experimental shading. The effects of this treatment on survival, morphology, phenology, physiology and growth were analysed by

  17. Decrease in sapling nutrient concentrations for six northern Rocky Mountain coniferous species

    Science.gov (United States)

    Theresa B. Jain; Russell T. Graham

    2015-01-01

    In the west, fire exclusion, timber harvest, and last century’s climate led to copious regeneration on millions of ha that now need tending. Without treatment, overcrowding increases competition, snow and ice damage potential, and ladder fuels. Limited funding prevents treating all of the affected ha, but by selling small trees for wood pellets, biofuel, or methanol,...

  18. Soil analysis based on sa,ples withdrawn from different volumes: correlation versus calibration

    Science.gov (United States)

    Lucian Weilopolski; Kurt Johnsen; Yuen. Zhang

    2010-01-01

    Soil, particularly in forests, is replete with spatial variation with respect to soil C. Th e present standard chemical method for soil analysis by dry combustion (DC) is destructive, and comprehensive sampling is labor intensive and time consuming. Th ese, among other factors, are contributing to the development of new methods for soil analysis. Th ese include a near...

  19. Explaining interspecific differences in sapling growth and shade tolerance in temperate forests

    NARCIS (Netherlands)

    Janse-ten Klooster, S.H.; Thomas, E.J.P.; Sterck, F.J.

    2007-01-01

    1. Species differences in growth and shade tolerance might contribute to coexistence of tree species. To explore how such differences depend on underlying plant traits, 14 tree species were investigated in temperate forests on sand and loess soils in the Netherlands. Plant traits were measured for

  20. Interplanting woody nurse crops promotes differential growth of black walnut saplings

    Science.gov (United States)

    J. O. Dawson; J. W. Van Sambeek

    1993-01-01

    Interplanting black walnut (Juglans nigra) with four different nitrogen fixing, woody nurse crops (Alnus glutinosa, Elaeagnus umbellata, E. angustifolia or Caragana arborescens) increased annual walnut height and stem diameter (dbh) growth overall by as much as 50% and...

  1. Seeds, saplings and gaps: size matters. A study in the tropical rain forest of Guyana

    NARCIS (Netherlands)

    Rose, S.A.

    2000-01-01

    Forest management for timber exploitation is dependent on the succesful regeneration of commercial timber species in gaps. This study evaluated the influence of gap size and seed mass on the processes of seedling recruitment, establishment, growth and survival in logged over and mature forest

  2. Evaluation of sapling height and density after clearcutting and group selection in the Missouri Ozarks

    Science.gov (United States)

    Guerric T. Good; Benjamin O. Knapp; Lance A. Vickers; David R. Larsen; John M. Kabrick

    2017-01-01

    Silvicultural decisions often affect the development and characteristics of a stand. Silvicultural regeneration events can have immediate and gradual impacts on stand development. The objective of this study was to evaluate the effects of two silvicultural regeneration methods, clearcutting and group selection, on the composition of trees that are likely to recruit to...

  3. Foliage nitrogen turnover: differences among nitrogen absorbed at different times by Quercus serrata saplings

    Science.gov (United States)

    Ueda, Miki U.; Mizumachi, Eri; Tokuchi, Naoko

    2011-01-01

    Background and Aims Nitrogen turnover within plants has been intensively studied to better understand nitrogen use strategies. However, differences among the nitrogen absorbed at different times are not completely understood and the fate of nitrogen absorbed during winter is largely uncharacterized. In the present study, nitrogen absorbed at different times of the year (growing season, winter and previous growing season) was traced, and the within-leaf nitrogen turnover of a temperate deciduous oak Quercus serrata was investigated. Methods The contributions of nitrogen absorbed at the three different times to leaf construction, translocation during the growing season, and the leaf-level resorption efficiency during leaf senescence were compared using 15N. Key Results Winter- and previous growing season-absorbed nitrogen significantly contributed to leaf construction, although the contribution was smaller than that of growing season-absorbed nitrogen. On the other hand, the leaf-level resorption efficiency of winter- and previous growing season-absorbed nitrogen was higher than that of growing season-absorbed nitrogen, suggesting that older nitrogen is better retained in leaves than recently absorbed nitrogen. Conclusions The results demonstrate that nitrogen turnover in leaves varies with nitrogen absorption times. These findings are important for understanding plant nitrogen use strategies and nitrogen cycles in forest ecosystems. PMID:21515608

  4. Nurse plants, tree saplings and grazing pressure : Changes in facilitation along a biotic environmental gradient

    NARCIS (Netherlands)

    Smit, Christian; Vandenberghe, Charlotte; den Ouden, Jan; Mueller-Schaerer, Heinz

    Current conceptual models predict that an increase in stress shifts interactions between plants from competitive to facilitative; hence, facilitation is expected to gain in ecological importance with increasing stress. Little is known about how facilitative interactions between plants change with

  5. Nurse plants, tree saplings and grazing pressure: changes in facilitation along a biotic environmental gradient

    NARCIS (Netherlands)

    Smit, C.; Vandenberghe, C.; Ouden, den J.; Muller-Scharer, H.

    2007-01-01

    Current conceptual models predict that an increase in stress shifts interactions between plants from competitive to facilitative; hence, facilitation is expected to gain in ecological importance with increasing stress. Little is known about how facilitative interactions between plants change with

  6. Tissue-level leaf toughness, but not lamina thickness, predicts sapling leaf lifespan and shade tolerance of tropical tree species

    NARCIS (Netherlands)

    Kitajima, K.; Poorter, L.

    2010-01-01

    Leaf toughness is thought to enhance physical defense and leaf lifespan. Here, we evaluated the relative importance of tissue-level leaf traits vs lamina thickness, as well as their ontogenetic changes, for structure-level leaf toughness and regeneration ecology of 19 tropical tree species. We

  7. Identity rather than richness drives local neighbourhood species composition effects on oak sapling growth in a young forest

    NARCIS (Netherlands)

    Dillen, Mathias; Kris, Verheyen; Smit, Christian

    2016-01-01

    In light of global biodiversity loss, the influence of species composition on ecosystem functioning has attracted increasing attention. However, questions remain whether neighbourhood species richness or identity is more important and what mechanisms drive these composition effects. We investigated

  8. Leaf antioxidant fluctuations and growth responses in saplings of Caesalpinia echinata Lam. (brazilwood) under an urban stressing environment.

    Science.gov (United States)

    Bulbovas, Patricia; de Moraes, Regina Maria; Spasiani Rinaldi, Mirian Cilene; Luiza Cunha, Adriana; Carvalho Delitti, Welington Braz; Domingos, Marisa

    2010-05-01

    We intended to establish how efficient the leaf antioxidant responses of C. echinata are against oxidative environmental conditions observed in an urban environment and their relations to growth and biomass parameters. Plants were grown for 15 months in four sites: Congonhas and Pinheiros, affected by pollutants from vehicular emissions; Ibirapuera, affected by high O(3) concentrations; and a greenhouse with filtered air. Fifteen plants were quarterly removed from each site for analysis of antioxidants, growth and biomass. Plants growing in polluted sites showed alterations in their antioxidants. They were shorter, had thicker stems and produced less leaf biomass than plants maintained under filtered air. The fluctuations in the levels of antioxidants were significantly influenced by combined effects of climatic and pollution variables. The higher were the antioxidant responses and the concentrations of pollutant markers of air contamination in each site the slower were the growth and biomass production. Copyright 2009 Elsevier Inc. All rights reserved.

  9. The Effect of Nitrogen Application on Boron Toxicity Reduction in Pistachio (Pistacia vera cv. Badami-Zarand Saplings

    Directory of Open Access Journals (Sweden)

    babak motesharezadeh

    2017-02-01

    Full Text Available Introduction: Boron is one of the seven essential microelements for the natural growth of plants. The toxicity of this element occurs in arid and semi-arid regions, which is because of its high level in soils and the irrigation water of mentioned regions. The aim of this study was to evaluate the effect of nitrogen application on boron toxicity tolerance in pistachio, Badami-Zarand variety. The effects of three nitrogen levels (0, 250, and 350 mg/kg of soil on the reduction of toxicity due to the three levels of boron (0, 15, and 30 mg/kg of soil were examined in Badami-Zarandi variety of pistachio under greenhouse conditions. After 7 months from sowing the seeds, pistachio seedlings were harvested and desired traits were measured. The results showed that by increasing boron application level, boron concentration in the shoot and root of seedlings increased whereas their dry weight decreased. Using of nitrogen reduced the negative effects of boron on the dry weight and led to increase dry weight and decrease boron concentration in the shoot and root of pistachio, Badami variety. Nitrogen application at the levels of 250 and 350 mg N per kg of soil reduced boron uptake in shoots by reinforcing plant vegetative system and increasing chlorophyll content by 13.5% and 30.2%, respectively and finally led to diluted boron concentration in the plant (dilution effect and reduced the effects of boron toxicity. Hence, optimized nitrogen application is suggested as one of the management methods in controlling Boron toxicity under these conditions. Materials and Methods: A factorial experiment based on randomized complete block design with four replications was carried out. Soil sampling was done in 0-30 cm depth in a zeekzack way from a pistachio garden that located in mahmoodiye area in Rafsanjan. The soil sample was air-dried and passed through a 2mm sieve. The soil chemical and physical properties were measured. In this study, badami-zarand cultivar seed was used because it is one of the most important pistachio cultivars. The seeds were soaked in water for 24 hours and disinfected by benomyl fungicide. When the seeds germinated, they were planted in the pots containing 4.5 kg soil and without drainage, so nutrients balance was kept during growing period. After 7 months, the seedlings were harvested and B was measured. Results and Discussion: The results showed that increasing the boron levels from 0 to 30 mg kg-1 led to decrease shoot dry weight from 3.72 to 2.45 gram and root DM from 2.28 to 1.50 gram. Increasing 30 mg kg-1 boron led to 2.8 times increase of shoot boron concentration. The averages of shoot boron concentration in the levels of 15 and 30 mg kg-1 boron were 87.6 and 122 mg kg-1DM, respectively. The boron toxicity level in Badami-Zarand cultivar is 8.9 mg kg-1 DM (Sepaskhahet al, 1994, so these levels were the cause of boron toxicity and boron toxicity symptoms were seen as leaf burn, often at the margins and the tips of older leaves. The results showed that increasing nitrogen levels led to decrease shoot boron concentration and increase their weight. The results also showed a significant negative correlation between the nitrogen levels and boron uptake. Boron uptake in the shoots of seedlings about 13.5 and 30.2 percent decreased when nitrogen levels increased. Shoot dry weight decreased when boron application increased, but it increased when nitrogen was used (Koohkan and Maftoun, 2009. Conclusion: The reduction of dry weight and increasing boron concentration occurred when increased boron application. The Maximum of boron uptake was seen by leaves, and boron toxicity symptoms were appeared as leaf burn especially at the tips and margins of older leaves. Since, boron is immobile in pistachio; it is absorbed by mass flow, so the accumulation of boron at older leaves is persuaded. Nitrogen reduced the bad effects of boron on dry weight and the bad effects of increasing boron concentration by the synthesis of chlorophyll, so it was more useful in shoot than root. Boron uptake was also reduced by nitrogen application. This effect of nitrogen is probably concerned to the increase of dry weight more than boron concentration (Dilution effect. On the other hand, nitrogen caused to increase leaf index and increase the number of seedling leaves. The injured leaves due to boron toxicity were restored, because of high leaf chlorophyll. It is suggested that this study will be done under field conditions for fertilizer application recommendations and to be used for creation of tolerant cultivars of pistachio.

  10. Restoring silvopastures with oak saplings: Effects of mulch and diameter class on survival, growth, and annual leaf-nutrient patterns

    Science.gov (United States)

    M. N. Jimenez; J. R. Pinto; M. A. Ripoll; A. Sanchez-Miranda; F. B. Navarro

    2014-01-01

    In Southwestern Spain, multifunctional silvopastoral systems consisting of pastureland and open oak woodlands are known as Dehesas. These, and other similar systems of the Mediterranean basin, are currently threatened by increasing intensive land use. As a consequence, oak regeneration is declining and is in need of adequate management and active restoration....

  11. Growth and mortality of thinned knobcone x Monterey pine saplings affected by engraver beetles and a hard freeze

    Science.gov (United States)

    William W. Oliver

    1979-01-01

    Mortality and diameter growth loss were severe on study plots in a thinned plantation of 9-year-old trees. California five-spined engravers killed 15 percent of the trees and a hard freeze killed 20 percent of the survivors. Mortality was higher and subsequent diameter growth was lower in trees with most of their needles freeze-killed than in trees less severely...

  12. RESEARCH ON IMPROVING THE RATE OF GERMINATION TO THE OAK SAPLINGS BY APPLYING THE TREATMENTS BEFORE SOWING ACORNS

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    Vasile Simonca

    2016-07-01

    Full Text Available In order to study a plant disease, one needs to know the symptomatic manifests, morphology and biology of the pathogen that causes mutual relations between the host plant and the pathogen, and the influence exerted by environmental conditions. In the fight against plant diseases, preventive measures are mainly used. These sought to determine the degree of impairment in nature pests of the acorn crop emergence percentage and seedling development in the first year of vegetation under the influence of prophylactic or curative treatments applied at sowing. using some new fungicides. To control these pathogens fungicides series of new generations were tested. Tests were made in several forest nurseries using acorn of several origins and several species of the genus Quercus. Acorns were treated before sowing and the effect of these treatments in health and seedling emergence percentage obtained was observed.

  13. Drought increases heat tolerance of leaf respiration in Eucalyptus globulus saplings grown under both ambient and elevated atmospheric [CO2] and temperature

    Science.gov (United States)

    Gauthier, Paul P. G.; Crous, Kristine Y.; Ayub, Gohar; Duan, Honglang; Weerasinghe, Lasantha K.; Ellsworth, David S.; Tjoelker, Mark G.; Evans, John R.; Tissue, David T.; Atkin, Owen K.

    2014-01-01

    Climate change is resulting in increasing atmospheric [CO2], rising growth temperature (T), and greater frequency/severity of drought, with each factor having the potential to alter the respiratory metabolism of leaves. Here, the effects of elevated atmospheric [CO2], sustained warming, and drought on leaf dark respiration (R dark), and the short-term T response of R dark were examined in Eucalyptus globulus. Comparisons were made using seedlings grown under different [CO2], T, and drought treatments. Using high resolution T–response curves of R dark measured over the 15–65 °C range, it was found that elevated [CO2], elevated growth T, and drought had little effect on rates of R dark measured at T drought on T response of R dark. However, drought increased R dark at high leaf T typical of heatwave events (35–45 °C), and increased the measuring T at which maximal rates of R dark occurred (T max) by 8 °C (from 52 °C in well-watered plants to 60 °C in drought-treated plants). Leaf starch and soluble sugars decreased under drought and elevated growth T, respectively, but no effect was found under elevated [CO2]. Elevated [CO2] increased the Q 10 of R dark (i.e. proportional rise in R dark per 10 °C) over the 15–35 °C range, while drought increased Q 10 values between 35 °C and 45 °C. Collectively, the study highlights the dynamic nature of the T dependence of R dark in plants experiencing future climate change scenarios, particularly with respect to drought and elevated [CO2]. PMID:25205579

  14. A comparison of daily water use estimates derived from constant-heat sap-flow probe values and gravimetric measurements in pot-grown saplings.

    Science.gov (United States)

    K.A. McCulloh; K. Winter; F.C. Meinzer; M. Garcia; J. Aranda; Lachenbruch B.

    2007-01-01

    The use of Granier-style heat dissipation sensors to measure sap flow is common in plant physiology, ecology, and hydrology. There has been concern that any change to the original Granier design invalidates the empirical relationship between sap flux density and the temperature difference between the probes. We compared daily water use estimates from gravimetric...

  15. Patterns in δ15N in roots, stems, and leaves of sugar maple and American beech seedlings, saplings, and mature trees

    Science.gov (United States)

    L.H. Pardo; P. Semaoune; P.G. Schaberg; C. Eagar; M. Sebilo

    2013-01-01

    Stable isotopes of nitrogen (N) in plants are increasingly used to evaluate ecosystem N cycling patterns. A basic assumption in this research is that plant δ15N reflects the δ15N of the N source. Recent evidence suggests that plants may fractionate on uptake, transport, or transformation of N. If the...

  16. Influence of resting and pine sawdust application on chemical changes in post-agricultural soil and the ectomycorrhizal community of growing Scots pine saplings

    Directory of Open Access Journals (Sweden)

    Małecka Monika

    2015-09-01

    Full Text Available Changes in chemical compounds and in ectomycorrhizal structure were determined for Scots pine growing on post agricultural soil lying fallow for 3, 6 and 15 years, after amendment with pine sawdust. Soil without any amendments was used as the control treatment. Comparing the ectomycorrhizal structure 15 years after the application of pine sawdust revealed no significant differences in abundance or species richness between soil with and without organic enrichment. The results showed that the ectomycorrhizal status depends on soil conditions (soil pH, nitrogen content, which remain unaffected by saw dust application. In all treatments, the most frequently occurring ectomycorrhizae genera were Dermocybe, Hebeloma, Suillus, Tomentella and Tricholoma. Two species (Paxillus involutus, Amanita muscaria were specific to the control plots that lay fallow for 15 years.

  17. Can thinning of overstory trees and planting of native tree saplings increase the establishment of native trees in exotic acacia plantations in south china?

    Science.gov (United States)

    SF Yuan; H Ren; N Liu; J Wang; QF Guo

    2013-01-01

    Assessing the effect of thinning of overstorey trees and planting of native trees will be helpful to better understand the vegetation restoration. A stand conversion experiment was conducted in a 12-year-old Acacia auriculiformis plantation in 1996. Treatments were thinning and underplanting, underplanting, thinning, and control. Results showed that...

  18. Stem wood properties of Populus tremuloides, Betula papyrifera and Acer saccharum saplings after three years of treatments to elevated carbon dioxide and ozone

    Science.gov (United States)

    Seija Kaakinen; Katri Kostiainen; Fredrik Ek; Pekka Saranpaa; Mark E. Kubiske; Jaak Sober; David F. Karnosky; Elina Vapaavuori

    2004-01-01

    The aim of this study was to examine the effects of elevated carbon dioxide [CO2] and ozone [O3] and their interaction on wood chemistry and anatomy of five clones of 3-year-old trembling aspen (Populus tremuloides Michx.). Wood chemistry was studied also on paper birch (Betula papyrifera...

  19. The impact of vessel size on vulnerability curves: data and models for within-species variability in saplings of aspen, Populus tremuloides Michx.

    Science.gov (United States)

    Cai, Jing; Tyree, Melvin T

    2010-07-01

    The objective of this study was to quantify the relationship between vulnerability to cavitation and vessel diameter within a species. We measured vulnerability curves (VCs: percentage loss hydraulic conductivity versus tension) in aspen stems and measured vessel-size distributions. Measurements were done on seed-grown, 4-month-old aspen (Populus tremuloides Michx) grown in a greenhouse. VCs of stem segments were measured using a centrifuge technique and by a staining technique that allowed a VC to be constructed based on vessel diameter size-classes (D). Vessel-based VCs were also fitted to Weibull cumulative distribution functions (CDF), which provided best-fit values of Weibull CDF constants (c and b) and P(50) = the tension causing 50% loss of hydraulic conductivity. We show that P(50) = 6.166D(-0.3134) (R(2) = 0.995) and that b and 1/c are both linear functions of D with R(2) > 0.95. The results are discussed in terms of models of VCs based on vessel D size-classes and in terms of concepts such as the 'pit area hypothesis' and vessel pathway redundancy.

  20. Moving water well: comparing hydraulic efficiency in twigs and trunks of coniferous, ring-porous, and diffuse-porous saplings from temperate and tropical forests

    Science.gov (United States)

    Katherine McCulloh; John S. Sperry; Barbara Lachenbruch; Frederick D. Meinzer; Peter B. Reich; Steven Voelker

    2010-01-01

    Coniferous, diffuse-porous and ring-porous trees vary in their xylem anatomy, but the functional consequences of these differences are not well understood from the scale of the conduit to the individual. Hydraulic and anatomical measurements were made on branches and trunks from 16 species from temperate and tropical areas, representing all three wood types. Scaling of...

  1. Moving water well: comparing hydraulic efficiency in twigs and trunks of coniferous, ring-porous, and diffuse-porous saplings from temperate and tropical forests.

    Science.gov (United States)

    McCulloh, Katherine; Sperry, John S; Lachenbruch, Barbara; Meinzer, Frederick C; Reich, Peter B; Voelker, Steven

    2010-04-01

    *Coniferous, diffuse-porous and ring-porous trees vary in their xylem anatomy, but the functional consequences of these differences are not well understood from the scale of the conduit to the individual. *Hydraulic and anatomical measurements were made on branches and trunks from 16 species from temperate and tropical areas, representing all three wood types. Scaling of stem conductivity (K(h)) with stem diameter was used to model the hydraulic conductance of the stem network. *Ring-porous trees showed the steepest increase in K(h) with stem size. Temperate diffuse-porous trees were at the opposite extreme, and conifers and tropical diffuse-porous species were intermediate. Scaling of K(h) was influenced by differences in the allometry of conduit diameter (taper) and packing (number per wood area) with stem size. *The K(h) trends were mirrored by the modeled stem-network conductances. Ring-porous species had the greatest network conductance and this value increased isometrically with trunk basal area, indicating that conductance per unit sapwood was independent of tree size. Conductances were lowest and most size-dependent in conifers. The results indicate that differences in conduit taper and packing between functional types propagate to the network level and have an important influence on metabolic scaling concepts.

  2. Long-term fertilization determines different metabolomic profiles and responses in saplings of three rainforest tree species with different adult canopy position

    Czech Academy of Sciences Publication Activity Database

    Gargalo-Garriga, A.; Wright, S. J.; Sardans, J.; Pérez-Trujillo, M.; Oravec, Michal; Večeřová, Kristýna; Urban, Otmar; Fernandez-Martinez, M.; Parella, T.; Peňuelas, J.

    2017-01-01

    Roč. 12, č. 5 (2017), č. článku e0177030. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) LO1415 Grant - others:Akademie věd České Republiky(CZ) M200871201 Institutional support: RVO:67179843 Keywords : lowland tropical forest * UV-B radiation * terrestrial ecosystem * elemental composition * rainforest Subject RIV: CE - Biochemistry Impact factor: 2.806, year: 2016

  3. Leaf traits and gas exchange in saplings of native tree species in the Central Amazon Características foliares e trocas gasosas em arvoretas de espécies nativas da Amazônia Central

    Directory of Open Access Journals (Sweden)

    Keila Rego Mendes

    2010-12-01

    Full Text Available Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA, leaf thickness (LT, and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season and August (dry season of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax and stomatal conductance (g s, and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]. Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot and leaf anatomy (leaf thickness.Os modelos climáticos globais prevêem mudanças na extensão da época seca na Amazônia, o que pode afetar a fisiologia das árvores. Os objetivos deste trabalho foram determinar o efeito da sazonalidade da precipitação e fração de céu visível (FSV no sub-bosque da floresta nas características foliares e trocas gasosas de 10 espécies florestais da Amazônia Central. Também examinou-se a relação entre área foliar específica (SLA, espessura da folha (LT e nitrogênio foliar em parâmetros fotossintéticos. Os resultados foram coletados nos meses de janeiro (época chuvosa e agosto (época seca de 2008. Observou-se um padrão de variação diurna na fotossíntese saturada por luz (Amax e na condutância estomática (g s. Independente da espécie, Amax foi menor na época seca. No entanto, não houve efeito da sazonalidade das chuvas em g s nem na capacidade fotossintética (Apot medida em [CO2] saturante. Apot e a espessura da folha (LT aumentaram com FSV, o contrário foi observado para a relação FSV-SLA. Também, observou-se uma relação positiva entre Apot por unidade de área e conteúdo de nitrogênio foliar, e entre Apot, por unidade de massa e SLA. Embora o regime das chuvas apenas levemente influenciou a umidade do solo, características fotossintéticas parecem responderem a fatores relacionados com as chuvas, o que repercute em Amax. Finalmente, relata-se que pequenas variações em FSV parecem afetar a fisiologia da folha (Apot e a anatomia foliar (espessura da folha.

  4. Predicting the recruitment of established regeneration into the sapling size class following partial cutting in the Acadian Forest Region: Using long-term observations to assess the performance of FVS-NE

    Science.gov (United States)

    David Ray; Chad Keyser; Robert Seymour; John Brissette

    2008-01-01

    Forest managers are increasingly called upon to provide long-term predictions of forest development. The dynamics of regeneration establishment, survival and subsequent recruitment of established seedlings to larger size classes is a critical component of these forecasts, yet remains a weak link in available models. To test the reliability of FVS-NE for simulating...

  5. Processing of spent pickling liquor formed during treatment of titanium products

    Science.gov (United States)

    Bykovsky, N. A.; Rahman, P. A.; Puchkova, L. N.; Fanakova, N. N.

    2017-10-01

    The article presents the research findings on processing of spent acid pickling liquor (SAPL) formed during etching of titanium products. The processing includes neutralizing the SAPL with alkali, filtering, drying and calcining the titanium hydroxide precipitate as well as electrochemical processing of the filtrate in an ion-exchange membrane cell. The proposed SAPL processing procedure allows obtaining titanium dioxide, sodium hydroxide and a mixture of acids. Titanium dioxide can be used in paint-and-varnish industry. The alkali can be used in neutralizing the SAPL. A mixture of acids is suitable for use in etching process of titanium products.

  6. Effects of long-term, elevated ultraviolet-B radiation on phytochemicals in the bark of silver birch (Betula pendula).

    Science.gov (United States)

    Tegelberg, Riitta; Aphalo, Pedro J; Julkunen-Tiitto, Riitta

    2002-12-01

    Long-term outdoor experiments were conducted to investigate the effects of elevated ultraviolet-B (UV-B, 280-320 nm) radiation on secondary metabolites (phenolics and terpenoids) and the main soluble sugars (sucrose, raffinose and glucose) in the bark of silver birch (Betula pendula Roth) saplings. Saplings were exposed to a constant 50% increase in erythemal UV irradiance (UV-B(CIE); based on the CIE (International Commission on Illumination) erythemal action spectrum) and a small increase in UV-A radiation (320-400 nm) for three growing seasons in an irradiation field in central Finland. Two control groups were used: saplings exposed to ambient radiation and saplings exposed to slightly increased UV-A radiation. Concentrations of sucrose, raffinose and glucose in bark were higher in UV-treated saplings than in saplings grown in ambient radiation, indicating that stem carbohydrate metabolism was changed by long-term elevated UV radiation. Saplings in the elevated UV-A + UV-B radiation treatment and the UV-A radiation control treatment had significantly increased concentrations of certain UV-absorbing phenolics, such as salidroside, 3,4'-dihydroxypropiophenone-3-glucoside, (+)-catechin and (-)-epicatechin compared with saplings in ambient radiation. In contrast, the radiation treatments had no effect on the non-UV-B-absorbing terpenoids, papyriferic acid and deacetylpapyriferic acid. We conclude that plant parts, in addition to leaves, accumulate specific phenolic UV-filters in response to UV radiation exposure.

  7. Effects of initial climatic conditions on growth and accumulation of fluoride and nitrogen in leaves of two tropical tree species exposed to industrial air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Furlan, Claudia Maria; Salatino, Antonio [Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, CP 11461, 05422-970, Sao Paulo, SP (Brazil); Domingos, Marisa [Secao de Ecologia, Instituto de Botanica, SMA, CP 4005, 01061-970, Sao Paulo (Brazil)

    2007-03-15

    Saplings of Tibouchina pulchra and Psidium guajava, cultivated under standardized soil conditions, were placed in two sites at Cubatao (state of Sao Paulo, southeast Brazil) to study the effects of air pollution on growth, biomass allocation and foliar nitrogen and fluoride concentrations. Thirty-six potted plants were maintained over two periods of one year (Jul/00 to Jun/01; Dec/00 to Nov/01) at each of two experimental sites with distinct levels of air pollution: Piloes River Valley (PV) with vegetation virtually unaffected by air pollution; and Mogi River Valley (MV) severely affected by pollutants released mainly by chemical, fertilizer, iron and steel industries. For both species, saplings growing at MV showed alterations of growth and biomass allocation, as well as increased leaf concentrations of nitrogen and fluoride. Comparing both experimental periods, the one starting in winter (the driest season in Southeastern Brazil) seemed to affect the saplings more severely, the differences of the measured parameters between MV and PV being higher than in the second period. Multivariate analysis revealed two groups of data: one representing the MV and the other the PV saplings. For both species, saplings growing at MV showed differences in chemical composition, growth and biomass allocation, compared with the PV saplings. The results suggested that seasonal conditions of the first months of sapling exposure (summer or winter) modulate the intensity of responses to pollution stress. (author)

  8. Role of planting stock size and fertilizing in initial growth performance of rowan (Sorbus aucuparia L. reforestation in a mountain frost hollow

    Directory of Open Access Journals (Sweden)

    Ivan Kuneš

    2014-08-01

    Full Text Available The aim of study: (1 to compare the survival rate, growth performance and nutrition of large and common-sized planting stock of rowan (Sorbus aucuparia L. on a frost-exposed site and (2 to assess whether fertilizing had any effect on the plantations.Area of study: The Jizera Mts., an area heavily disturbed by air pollution situated on the Czech-Polish border close to GermanyMaterials and methods: Two types of planting stock were tested in a mountain frost hollow on an acidic mountain humic podsol: (a the bare-rooted saplings 131–140 cm tall and (b common-sized containerized transplants 26–35 cm. One half of the saplings and common-sized transplants were left untreated and the other half were fertilized with a low dose (30 g per tree of a slow release fertilizer based on methylene urea and potassium magnesium phosphate. Growth performance and nutrition of plantations were investigated.Main results: Due to serious deformations and stem breakages inflicted by snow and frost, the prospects of common-sized transplants seem much worse than those of saplings. The height growth of saplings was significantly more rapid than that of common-sized transplants. As for growth, neither the saplings nor common-sized transplants did significantly respond to fertilizing. The effects of fertilizing on nutrition of rowans were unconvincing. The extreme temperature events during growth seasons and snow deformations in winters might be the decisive factors influencing growth performance of rowans under referred conditions.Research highlights: On the frost-exposed sites, the height of taller saplings might partly compensate for a missing shelter of forest stand since the terminal leaders are above ground-frost zone.Key words: mountain ash; sapling; common-sized transplants; nutritional status; temperature.Abbreviations: CS – Control Saplings; CT – Control Transplants; FS – Fertilized Saplings; FT – Fertilized Transplants

  9. The Effect of Symbiotic Ant Colonies on Plant Growth: A Test Using an Azteca-Cecropia System: e0120351

    National Research Council Canada - National Science Library

    Oliveira, Karla N; Coley, Phyllis D; Kursar, Thomas A; Kaminski, Lucas A; Moreira, Marcelo Z; Campos, Ricardo I

    2015-01-01

    .... In the field, we measured the growth of Cecropia glaziovii saplings and compared individuals that were naturally colonized by Azteca muelleri ants with uncolonized plants in different seasons (wet and dry...

  10. LBA-ECO CD-02 Leaf Level Gas Exchange, Chemistry, and Isotopes, Amazonia, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports leaf gas flux and leaf properties from samples collected from trees, liana, pasture saplings, and pasture grass located at eight...

  11. LBA-ECO CD-02 Leaf Level Gas Exchange, Chemistry, and Isotopes, Amazonia, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports leaf gas flux and leaf properties from samples collected from trees, liana, pasture saplings, and pasture grass located at eight different...

  12. Draft Environmental Impact Statement. Guam Cleanup of Uruno Beach

    Science.gov (United States)

    1987-02-01

    Piper quahamense was a common large herb and saplings of Aglaia mariannensis, Neisopermum oppositifolia, Morinda citrifolia and Cvcas circinalis were...Macaranqa thompsonii, Neisospermum oppositfolia, Morinda citrfolia, Dendrocnide latifolia and Cycas circinalis. The vegetation of the steep cliffs

  13. Leaf gas exchange characteristics of three neotropical mangrove species in response to varying hydroperiod

    Science.gov (United States)

    Ken W. Krauss; Robert R. Twilley; Thomas w. Doyle; Emile S. Gardiner

    2006-01-01

    We determined how different hydroperiods affected leaf gas exchange characteristics of greenhouse-grown seedlings (2002) and saplings (2003) of the mangrove species Avicennia germinans (L.) Stearn., Laguncularia racemosa (L.) Gaertn. f., and Rhizophora mangle L. Hydroperiod treatments included...

  14. Effect of ectomycorrhizae on growth and establishment of sal (Shorea robusta seedlings in central India

    Directory of Open Access Journals (Sweden)

    ABHISHEK PYASI

    2013-05-01

    Full Text Available Pyasi A, Soni KK, Verma RK. 2013. Effect of ectomycorrhizae on growth and establishment of sal (Shorea robusta seedlings in central India. Nusantara Bioscience 5: 44-49. The aim of the present study was to develop ectomycorrhiza in sal sapling at outside the sal growing areas. For this purpose sal seedling were raised at Jabalpur which is around 80 km away from natural sal forest (Motinala, MP. Seed sowing was done with inoculation of ectomycorrhizal inocula prepared by isolating the fungi from surface sterilised young basidiocarp of Lycoperdon compactum and Russula michiganensis. The inocula of ectomycorrhizal fungus were prepared in wheat grains treated with gypsum. The synthesis of ectomycorrhiza was observed in the sapling planted in the experimental field at Jabalpur with production of basidiocarp of Lycoperdon compactum near saplings. The mycorrhized saplings also showed higher growth indices.

  15. NEEDLE ANATOMY CHANGES WITH INCREASING TREE AGE IN DOUGLAS FIR

    Science.gov (United States)

    Morphological differences between old growth and sapling (Pseudotsuga menziesii, (Mirb.) Franco) Douglas fir trees may extend to differences in needle anatomy. We used microscopy with image analysis to compare and quantify anatomical parameters in cross-sections of previous year...

  16. Understory-overstory relationships in ponderosa pine forests, Black Hills, South Dakota

    Science.gov (United States)

    Daniel W. Uresk; Kieth E. Severson

    1989-01-01

    Under-story-overstory relationships were examined over 7 different growing stock levels(GSLs) of 2 size classes(saplings,8-10 cm d.b.h. and poles, 15-18 cm d.b.h.) of ponderosa pine (Pinus ponderosa) in the Black Hills, South Dakota. Generally, production of graminoids, forbs, and shrubs was similar between sapling and pole stands. Trends among GSLs were also similar...

  17. The contribution of the roumanian research concerning the collecting and use of germoplasm from walnut trees

    Directory of Open Access Journals (Sweden)

    Eliane-Teodora STANCIOIU

    2009-05-01

    Full Text Available In Romania, due to the poor variety of the rootstock, the walnut tree is grafted by mixing different Junglas regia L. saplings. In the County of Gorj, 19 selections corresponding to the mains characteristics of the rootstock have been determinate. On these selections, various studies determinating their biological nature have been done; fruits have been gathered and used for the experimental reproductions in the sapling nursery. According to the selection criteria, every year, on each biotype, the springing percentage have been counted, together with the medium diameter by package, the medium height, the percentage of STAS saplings obtained, and of thriving in the grafting process using the Jupînesti type. The results of this analyse done in the sapling nursery have reached to the conclusion that the selection SL-10-TJ has obtained the highest springing percentage (86%. The medium height of the saplings indicates an irregular growth, which varies between 42 cm (SL-1-TP and 63 cm (EL-7-TJ. As per the diameter by package, it varies between 14.1 mm (SL-1-TJ and 16.5 mm (SL-18-TJ. The percentage of the springing STAS saplings is between 17% for the selection SL-15-TJ and 78% for the selection SL-6-TJ, and the thriving in the grafting process is high for all the selection, except for SL-9-TJ, with only 55%.

  18. Juvenile tree growth correlates with photosynthesis and leaf phosphorus content in central Amazonia

    Directory of Open Access Journals (Sweden)

    Ricardo Antonio Marenco

    2015-04-01

    Full Text Available Light and soil water availability may limit carbon uptake of trees in tropical rainforests. The objective of this work was to determine how photosynthetic traits of juvenile trees respond to variations in rainfall seasonality, leaf nutrient content, and opening of the forest canopy. The correlation between leaf nutrient content and annual growth rate of saplings was also assessed. In a terra firme rainforest of the central Amazon, leaf nutrient content and gas exchange parameters were measured in five sapling tree species in the dry and rainy season of 2008. Sapling growth was measured in 2008 and 2009. Rainfall seasonality led to variations in soil water content, but it did not affect leaf gas exchange parameters. Subtle changes in the canopy opening affected CO2 saturated photosynthesis (A pot, p = 0.04. Although A pot was affected by leaf nutrient content (as follows: P > Mg > Ca > N > K, the relative growth rate of saplings correlated solely with leaf P content (r = 0.52, p = 0.003. At present, reduction in soil water content during the dry season does not seem to be strong enough to cause any effect on photosynthesis of saplings in central Amazonia. This study shows that leaf P content is positively correlated with sapling growth in the central Amazon. Therefore, the positive effect of atmospheric CO2 fertilization on long-term tree growth will depend on the ability of trees to absorb additional amount of P

  19. Effects of long-term elevated ultraviolet-B radiation on phytochemicals in the bark of silver birch (Betula pendula)

    Energy Technology Data Exchange (ETDEWEB)

    Tegelberg, R.; Julkunen-Tiitto, R. [Joensuu Univ., Dept. of Biology, Joensuu (Finland); Aphalo, P. J. [Joensuu Univ., Faculty of Forestry, Joensuu (Finland)

    2002-12-01

    The effects of long-term ultraviolet-B radiation on the concentrations of secondary metabolites such as phenolics and terpenoids in the bark of silver birch saplings were studied. The effects of ultraviolet-B on the concentrations of the main soluble sugars such as sucrose, raffinose, and glucose in silver birch stem were also investigated, given that they are involved in the transpiration and allocation of assimilated carbon, and UV-B-induced changes may affect tree growth. Concentrations of sucrose, raffinose and glucose in bark were found to be higher in UV-treated saplings than in saplings grown in ambient radiation, indicating that stem carbohydrate metabolism was changed by long-term exposure to elevated UV radiation. Saplings in elevated UV-A + UV-B radiation treatment and UV-A radiation control treatment had shown significantly increased concentrations of certain UV-absorbing phenolics compared with saplings in ambient radiation. No effect of radiation treatment was observed on non-UV-B-absorbing terpenoids. These observations led to the conclusion that plant parts accumulate specific phenolic UV-filters in response to UV radiation exposure. The accumulation of sugars in the stems of silver birch saplings in response to UV radiation is believed to affect tree growth, possibly because of a reduction of alpha-cellulose content and consequent reduction in cell wall production. 36 refs., 1 tab., 2 figs.

  20. Influence of neighboring plants on the dynamics of an ant-acacia protection mutualism.

    Science.gov (United States)

    Palmer, Todd M; Riginos, Corinna; Damiani, Rachel E; Morgan, Natalya; Lemboi, John S; Lengingiro, James; Ruiz-Guajardo, Juan C; Pringle, Robert M

    2017-12-01

    Ant-plant protection symbioses, in which plants provide food and/or shelter for ants in exchange for protection from herbivory, are model systems for understanding the ecology of mutualism. While interactions between ants, host plants, and herbivores have been intensively studied, we know little about how plant-plant interactions influence the dynamics of these mutualisms, despite strong evidence that plants compete for resources, that hosting ants can be costly, and that host-plant provisioning to ants can therefore be constrained by resource availability. We used field experiments in a semiarid Kenyan savanna to examine interactions between the ant-plant Acacia drepanolobium, neighboring grasses, and two species of symbiotic acacia-ants with divergent behaviors: Crematogaster mimosae, an aggressive symbiont that imposes high costs to host trees via consumption of extrafloral nectar, and Tetraponera penzigi, a less-protective symbiont that imposes lower costs because it does not consume nectar. We hypothesized that by competing with acacias for resources, neighboring grasses (1) reduce hosts' ability to support costly C. mimosae, while having little or no effect on the ability of hosts to support low-cost T. penzigi, and (2) reduce sapling growth rates irrespective of ant occupant. We factorially manipulated the presence/absence of grasses and the identity of ant occupants on saplings and evaluated effects on colony survivorship and sapling growth rates over 40 weeks. Contrary to prediction, the high-cost/high-reward nectar-dependent mutualist C. mimosae had higher colony-survival rates on saplings with grass neighbors present. Grasses appear to have indirectly facilitated the survival of C. mimosae by reducing water stress on host plants; soils under saplings shaded by grasses had higher moisture content, and these saplings produced more active nectaries than grass-removal saplings. Consistent with prediction, survival of low-cost/low-reward T. penzigi did

  1. Unlocking the forest inventory data: relating individual tree performance to unmeasured environmental factors.

    Science.gov (United States)

    Lichstein, Jeremy W; Dushoff, Jonathan; Ogle, Kiona; Chen, Anping; Purves, Drew W; Caspersen, John P; Pacala, Stephen W

    2010-04-01

    Geographically extensive forest inventories, such as the USDA Forest Service's Forest Inventory and Analysis (FIA) program, contain millions of individual tree growth and mortality records that could be used to develop broad-scale models of forest dynamics. A limitation of inventory data, however, is that individual-level measurements of light (L) and other environmental factors are typically absent. Thus, inventory data alone cannot be used to parameterize mechanistic models of forest dynamics in which individual performance depends on light, water, nutrients, etc. To overcome this limitation, we developed methods to estimate species-specific parameters (thetaG) relating sapling growth (G) to L using data sets in which G, but not L, is observed for each sapling. Our approach involves: (1) using calibration data that we collected in both eastern and western North America to quantify the probability that saplings receive different amounts of light, conditional on covariates x that can be obtained from inventory data (e.g., sapling crown class and neighborhood crowding); and (2) combining these probability distributions with observed G and x to estimate thetaG using Bayesian computational methods. Here, we present a test case using a data set in which G, L, and x were observed for saplings of nine species. This test data set allowed us to compare estimates of thetaG obtained from the standard approach (where G and L are observed for each sapling) to our method (where G and x, but not L, are observed). For all species, estimates of thetaG obtained from analyses with and without observed L were similar. This suggests that our approach should be useful for estimating light-dependent growth functions from inventory data that lack direct measurements of L. Our approach could be extended to estimate parameters relating sapling mortality to L from inventory data, as well as to deal with uncertainty in other resources (e.g., water or nutrients) or environmental factors (e

  2. Hydraulic architecture and photoinhibition influence spatial distribution of the arborescent palm Euterpe edulis in subtropical forests.

    Science.gov (United States)

    Gatti, M Genoveva; Campanello, Paula I; Villagra, Mariana; Montti, Lía; Goldstein, Guillermo

    2014-06-01

    Physiological characteristics of saplings can be considered one of the most basic constraints on species distribution. The shade-tolerant arborescent palm Euterpe edulis Mart. is endemic to the Atlantic Forest of Argentina, Brazil and Paraguay. At a local scale, saplings of this species growing in native forests are absent in gaps. We tested the hypothesis whether sensitivity to photoinhibition or hydraulic architecture constrains the distribution of E. edulis saplings in sun-exposed forest environments. Using shade houses and field studies, we evaluated growth, survival, hydraulic traits and the susceptibility of Photosystem II to photoinhibition in E. edulis saplings under different growth irradiances. Survival rates in exposed sites in the field were very low (a median of 7%). All saplings exhibited photoinhibition when exposed to high radiation levels, but acclimation to a high radiation environment increased the rate of recovery. Petiole hydraulic conductivity was similar across treatments regardless of whether it was expressed per petiole cross-sectional area or per leaf area. At the plant level, investment in conductive tissues relative to leaf area (Huber values) increased with increasing irradiance. Under high irradiance conditions, plants experienced leaf water potentials close to the turgor-loss point, and leaf hydraulic conductance decreased by 79% relative to its maximum value. Euterpe edulis saplings were able to adjust their photosynthetic traits to different irradiance conditions, whereas hydraulic characteristics at the leaf level did not change across irradiance treatments. Our results indicate that uncoupling between water demand and supply to leaves apparently associated with high resistances to water flow at leaf insertion points, in addition to small stems with low water storage capacity, weak stomatal control and high vulnerability of leaves to hydraulic dysfunction, are the main ecophysiological constraints that prevent the growth and

  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. Indirect facilitation becomes stronger with seedling age in a degraded seasonally dry forest

    Science.gov (United States)

    Torres, Romina C.; Renison, Daniel

    2016-01-01

    In seasonally dry forests direct facilitation by woody species due to amelioration of harsh abiotic conditions could be important during germination and early establishment of tree seedlings, and under some species but not others. Recent research suggests that at later stages facilitation by woody species may be indirect due to protection of saplings from herbivores, implying that under absence of herbivores reforestation programs may plant saplings in unprotected open sites. We used the native tree Lithraea molleoides from central Argentina as a model species to test this hypothesis. We performed a seeding and planting experiment simulating early and late establishment respectively, which included 234 study plots situated in herbaceous, shrub and tree patches of differing species composition and under two herbivore treatments (grazed and ungrazed) and replicated at three sites. Seedling counts averaged 0.82% of the sown seeds after 6 months, were highest under shrubs and lowest in open patches, and were influenced by woody species composition only in tree patches (all P values importance of indirect facilitation through protection from herbivores, as we recorded the highest sapling survival and growth at tree and shrub patches and the lowest in open patches (all P values species composition on sapling survival and growth (all P values > 0.05). We conclude that direct facilitation is involved at all studied stages while indirect facilitation becomes increasingly important at the sapling stage.

  5. The impact of small terrestrial mammals on beech (Fagus sylvatica plantations in spruce monoculture

    Directory of Open Access Journals (Sweden)

    Luboš Purchart

    2007-01-01

    Full Text Available Little is known about the impact of small terrestrial mammals on forest regeneration as yet. In order to determine the level of small rodent impact on artificial forest regeneration, 508 saplings have been researched in a spruce monoculture in the Drahany Uplands. With the objective to hone the interpretation of the data, small terrestrial rodents were trapped to help determine species spectrum. The occurrence of Apodemus flavicollis, Clethrionomys glareolus and Sorex araneus was verified. In 52 cases damage to the trunk caused by small rodents was monitored (10.1% of all saplings. 8 specimens (1.6% had their branches nibbled and 9 saplings (1.8% had tips of branches or trunk tops browsed. Browsing by Lepus europaeus – 423 (83.3% of all damaged specimens was significant.

  6. Physiological Responses to Prolonged Drought Differ Among Three Oak (Quercus) Species

    Science.gov (United States)

    Cooper, C. E.; Moore, G. W.; Vogel, J. G.; Muir, J. P.

    2015-12-01

    The physiological response of plants to water stress provides insights into which species may survive in exceptional drought conditions. This study conducted on a remnant post oak savanna site in College Station, Texas, examined how drought affected the physiology of three native oak species. In June 2014, after a period of equal watering, we subjected three year old Quercus shumardii (Shumard oak; SO), Q. virginiana (live oak; LO), and Q. macrocarpa (bur oak; BO) saplings to one of two watering treatments: 1) watered, receiving the equivalent of theaverage precipitation rate and 2) droughted, receiving a 100% reduction in precipitation. We measured predawn (ΨPD) and midday (ΨMD) leaf water potential; midday gas exchange (MGE) parameters including photosynthesis (Al), transpiration (T), stomatal conductance (gsw); and leaf soluble (SS) and non-soluble sugar (NSS) concentrations monthly between June and October 2014. Drought stress responses were evident after only one month of induced drought. Droughted saplings showed reduced ΨPD, ΨMD, and MGE (P ≤ 0.05) in comparison to watered saplings of the same species. LO saplings exhibited greater MGE (P ≤ 0.05) while maintaining similar LWP to their respective watered and droughted BO and SO counterparts. Droughted LO exhibited MGE rates similar to those of watered BO and SO (P ≤ 0.05), while watered LO adjusted its MGE rates to changes in water availability better than BO and LO during short-term drought. Compared to water saplings, droughted saplings had greater leaf SS (P = 0.08) and lower NSS concentrations (P = 0.10), possibly due to the conversion of NSS to SS and other simple compounds and reduced consumption of SS for growth by the droughted saplings. Although SO and BO exhibited similar photosynthesis rates, leaf total sugar (SS+NSS) concentration was greater in SO (P ≤ 0.05). By displaying the greatest average photosynthesis rate (P ≤ 0.05), LO should have accumulated the greatest amount of carbon

  7. Impact of straw and rock-fragment mulches on soil moisture and early growth of holm oaks in a semiarid area

    Science.gov (United States)

    M. N. Jimenez; J. R. Pinto; M. A. Ripoll; A. Sanchez-Miranda; F. B. Navarro

    2017-01-01

    Planted seedlings and saplings usually exhibit low survival and growth rates under dry Mediterranean environments, especially late-successional species such as Quercus. In this work, we studied the effects of straw and rock fragment mulches on the establishment conditions of holm oak (Quercus ilex L. subsp. ballota (Def.) Samp.) in SE Spain. Soil moisture was...

  8. Storage and flux of carbon in live trees, snags, and logs in the Chugach and Tongass national forests

    Science.gov (United States)

    Tara Barrett

    2014-01-01

    Carbon storage and flux estimates for the two national forests in Alaska are provided using inventory data from permanent plots established in 1995–2003 and remeasured in 2004–2010. Estimates of change are reported separately for growth, sapling recruitment, harvest, mortality, snag recruitment, salvage, snag falldown, and decay. Although overall aboveground carbon...

  9. On the formation of dense understory layers in forests worldwide: consequences and implications for forest dynamics, biodiversity, and succession

    Science.gov (United States)

    Alejandro A. Royo; Walter P. Carson

    2006-01-01

    The mechanistic basis underpinning forest succession is the gap-phase paradigm in which overstory disturbance interacts with seedling and sapling shade tolerance to determine successional trajectories. The theory, and ensuing simulation models, typically assume that understory plants have little impact on the advance regeneration layer's composition. We challenge...

  10. Emerald ash borer aftermath forests: The dynamics of ash mortality and the responses of other plant species

    Science.gov (United States)

    Kathleen S. Knight; Daniel A. Herms; John Cardina; Robert Long; Joanne Rebbeck; Kamal J.K. Gandhi; Annemarie Smith; Wendy S. Klooster; Catherine P. Herms; Alejandro A. Royo

    2010-01-01

    The effects of emerald ash borer (EAB) (Agrilus planipennis) on forest ecosystems are being studied through a collaborative research program involving the U.S. Forest Service's Northern Research Station and The Ohio State University. We are monitoring the decline and mortality of >4,500 ash trees and saplings, EAB population density, changes...

  11. Wood properties of immature ponderosa pine after thinning

    Science.gov (United States)

    Donald C. Markstrom; Harry E. Troxell; C. E. Boldt

    1983-01-01

    Trees from growing stock levels of 20, 60, and 100 in sapling and pole stands were sampled at three vertical positions -zero, 25, and 50 percent of total height above the 1-foot stump. Wood grown during the 10-year period after initial thinning was compared for growth and wood properties. Wide differences in radial growth, induced by thinning treatments, were not...

  12. Ozone impairs autumnal resorption of nitrogen from birch (Betula pendula) leaves, causing an increase in whole-tree nitrogen loss through litter fall

    National Research Council Canada - National Science Library

    Uddling, Johan; Karlsson, Per Erik; Glorvigen, Anders; Selldén, Gun

    2006-01-01

    Saplings of one half-sib family of birch, Betula pendula Roth, were exposed to three ozone concentrations (non-filtered air (NF); non-filtered air + 10-20 nmol O3 mol−1 (NF+); non-filtered air + 40-60 nmol O3 mol−1 (NF...

  13. Modelling functional trait acclimation for trees of different height in a forest light gradient: emergent patterns driven by carbon gain maximization

    NARCIS (Netherlands)

    Sterck, F.J.; Schieving, F.

    2011-01-01

    Forest trees show large changes in functional traits as they develop from a sapling in the shaded understorey to an adult in the light-exposed canopy. The adaptive function of such changes remains poorly understood. The carbon gain hypothesis suggests that these changes should be adaptive

  14. An ecological classification system for the central hardwoods region: The Hoosier National Forest

    Science.gov (United States)

    James E. Van Kley; George R. Parker

    1993-01-01

    This study, a multifactor ecological classification system, using vegetation, soil characteristics, and physiography, was developed for the landscape of the Hoosier National Forest in Southern Indiana. Measurements of ground flora, saplings, and canopy trees from selected stands older than 80 years were subjected to TWINSPAN classification and DECORANA ordination....

  15. Effects of habitat on stand productivity in the White Mountains of New Hampshire

    Science.gov (United States)

    William B. Leak

    1979-01-01

    Mean annual biomass production of sapling stands was higher on washed tills, which have a hardwood climax, than on habitats having a softwood climax. However, biomass production of poletimber stands did not differ significantly among habitats. Apparently, differences among habitats in characteristics species composition tends to mask differences in biomass productivity...

  16. KEANEKARAGAMAN TUMBUHAN SEKITAR AREAL PENANAMAN W-BRIDGE PROJECT DI TAHURA SULTAN ADAM KALIMANTAN SELATAN

    Directory of Open Access Journals (Sweden)

    Trisnu Satriadi

    2016-10-01

    Full Text Available The aim of this research was to know the biodiversity of flora around the W - bridge reforestation project area in Forest Parks of Sultan Adam, South Kalimantan.  The research method used field survey with a purposive sampling and using the line transect.  Based on analysis found that at the bottom block, found 8 ground vegetations, 11 seedlings, 14 saplings, 7 poles and 10 trees. Dominant vegetation for ground vegetation is Laladingan (Pogonatherum sp., for seedling is Tengkook Ayam (Cryptocarya sp., for sapling and pole are Mahang (Macaranga sp., and for tree is Jambu Burung (Eugenia sp.. At the top block, found 15 ground vegetations, 17 seedlings, 12 saplings , 6 poles, and 5 trees. Dominant vegetation for ground vegetation is Tempukas, for seedling is Tengkook Ayam, for sapling and pole are Alaban Kapas (Vitex pubescens and for tree is Bangkinang Burung (Ficus sp.. Both of blocks has moderate diversity index (1.540 - 2.564 and low similarity index (0 - 20.588.

  17. NANCEIFeb-rU-a-rY

    Indian Academy of Sciences (India)

    wi th leaf litter. The sholas have often been referred to as living fossils. This is essentially because of their inability to expand, due to the nature of the climatic conditions in the area. The action of the frost and the sun in the morning prevents any saplings from surviving in the grassland. However, the temperature in the sholas ...

  18. Fire and longleaf pine physiology - Does timing affect response? In: Proc

    Science.gov (United States)

    Mary Anne Sword Sayer; James D. Haywood

    2009-01-01

    Southern pines vary in their response to the loss of leaf area by crown scorch. We hypothesize that they tolerate crown scorch by at least three recovery mechanisms, but the function of these mechanisms is season-dependent. Using sapling longleaf pine as a model and experimental results from central Louisiana, U.S.A., our objective is to present examples recovery from...

  19. Logging, arboricide treatments and regeneration at Budongo Forest ...

    African Journals Online (AJOL)

    most abundant species such as Crototon, Cello spp. And. Aningeria (Upper storey); Lasioa'iscus, Strambosia,. F unlumia (Middle storey), and Rinorea, Alchornea,. Trichi/ia ruhescens (Undersorey) This would strengthen the capability to manipulate regeneration and growth conditions at the sapling pole and mature stages.

  20. Production of nursery-reared seedlings of the gray mangrove ...

    African Journals Online (AJOL)

    Moderate germination percentage, leaf morphology and stem growth was recorded for the tapwater treatment. The high salinity treatment of 42 ‰ (100 % seawater) inhibited seed germination. These results could be used in mass production of seedlings and saplings during the process of restoration of this threatened ...

  1. Leaf function in tropical rain forest canopy trees : the effect of light on leaf morphology and physiology in different-sized trees

    NARCIS (Netherlands)

    Rijkers, T.

    2000-01-01

    In this thesis the effect of constant and fluctuating light availability on several leaf traits was studied for naturally growing trees of different sizes, i.e . from sapling to adult canopy tree, of five species in a tropical rain forest in French Guiana. Leaf

  2. Physiological responses of Eucalyptus nitens × nitens under ...

    African Journals Online (AJOL)

    One group of plants was kept regularly watered (control), and another group was subjected to four cycles of water stress (drought) whereby water was withheld for periods lasting 6, 10, 10 and 14 d, with 4 d of regular watering (recovery) inbetween. A drought cycle was terminated once saplings showed signs of wilting.

  3. Effects of timber size-class on predation of artificial nests in extensive forest

    Science.gov (United States)

    Richard M. DeGraaf; Per. Angelstam

    1993-01-01

    Depredation on artificial ground and cup nests in even-aged seedling/sapling, pole, and mature stands of continuous northern hardwood forest was studied in the White Mountain National Forest in New Hampshire, USA from May to June 1988. Track-board nests were used to identify predators of ground nests; plain ground nests and cup nests were used to investigate the...

  4. Short-term dynamics of second-growth mixed mesophytic forest strata in West Virginia

    Science.gov (United States)

    Cynthia C. Huebner; Steven L. Stephenson; Harold S. Adams; Gary W. Miller

    2007-01-01

    The short-term dynamics of mixed mesophytic forest strata in West Virginia were examined using similarity analysis and linear correlation of shared ordination space. The overstory tree, understory tree, shrub/vine, and herb strata were stable over a six year interval, whereas the tree seedling and sapling strata were unstable. All strata but the shrub/vine and tree...

  5. Presettlement and modern disturbance regimes in coast redwood forests: Implications for the conservation of old-growth stands

    Science.gov (United States)

    C.G. Lorimer; D.G. Porter; M.A. Madej; J.D. Stuart; S.D. Veirs; S.P. Norman; K.L OHara; W.J.. Libby

    2009-01-01

    Coast redwood (Sequoia sempervirens), a western North American conifer of ancient lineage, has a paradoxical combination of late-successional characteristics and strong adaptations to disturbance. Despite its shade tolerance and heavy dominance of the canopy on many sites, redwood saplings are uncommon in upland old-growth stands. Information needed...

  6. interfaces of regeneration, structure, diversity and uses of some ...

    African Journals Online (AJOL)

    ADMIN

    Department of Biology Education, College of Education, Addis Ababa University. PO Box, 1176, Addis Ababa, ... Historical document indicated that Ethiopia had experienced ..... Seedlings (SE), saplings (SA) and tree/shrub (T/Sh) distribution of some selected species occurring in Bonga Forest. 0. 100. 200. 300. 400. 500.

  7. Occurrence and control of paper mulberry (broussonetia papyrifera ...

    African Journals Online (AJOL)

    Pole-sized trees of different stump heights and diameter classes treated with systemic herbicide failed to coppice after 24 weeks. The study showed that manually uprooting seedlings and saplings, and cutting followed by squirting the stumps of pole-sized trees with the appropriate chemicals would be effective measure to ...

  8. Ozone exposure, uptake, and response of different-sized black cherry trees

    Science.gov (United States)

    Todd S. Frederickson; John M. Skelly; Kim C. Steiner; Thomas E. Kolb

    1996-01-01

    Differences in exposure, uptake and relative sensitivity to ozone between seedling, sapling, and canopy black cherry (Prunus serotina Ehrh.) trees were characterized during two growing seasons in north central Pennsylvania. Open-grown trees of all sizes received a similar amount of ozone exposure. Seedlings had greater foliar ozone injury, expressed...

  9. Dynamics of whlte pine in New England

    Science.gov (United States)

    William B. Leak; J.B. Cullen; Thomas S. Frieswyk

    1995-01-01

    Analysis of growth, regeneration, and quality changes for white pine between the 1970's and 1980's in the six-state New England region. Growth rates seemed comparable among ail states except Rhode Island, where the percentage of growth (1.71%) seemed low. Over all states, the proportion of acreage in seedling/sapling white pine stands averaged too low (8%) to...

  10. Improving tree age estimates derived from increment cores: a case study of red pine

    Science.gov (United States)

    Shawn Fraver; John B. Bradford; Brian J. Palik

    2011-01-01

    Accurate tree ages are critical to a range of forestry and ecological studies. However, ring counts from increment cores, if not corrected for the years between the root collar and coring height, can produce sizeable age errors. The magnitude of errors is influenced by both the height at which the core is extracted and the growth rate. We destructively sampled saplings...

  11. Effect of weed control treatments on total leaf area of plantation black walnut (Juglans nigra)

    Science.gov (United States)

    Jason Cook; Michael R. Saunders

    2013-01-01

    Determining total tree leaf area is necessary for describing tree carbon balance, growth efficiency, and other measures used in tree-level and stand-level physiological growth models. We examined the effects of vegetation control methods on the total leaf area of sapling-size plantation black walnut trees using allometric approaches. We found significant differences in...

  12. Initial growth of Pterygota macrocarpa Schumann (Sterculiaceae ...

    African Journals Online (AJOL)

    The results showed that the average height of saplings in media of low light is statistically different from that obtained in highly sunny environment (F = 4.391, P = 0.0370). In contrast, the mean diameter and the mean of leafs production did not show a significant difference in these environments. Furthermore, the study ...

  13. Plant responses to extreme climatic events: a field test of resilience capacity at the southern range edge.

    Directory of Open Access Journals (Sweden)

    Asier Herrero

    Full Text Available The expected and already observed increment in frequency of extreme climatic events may result in severe vegetation shifts. However, stabilizing mechanisms promoting community resilience can buffer the lasting impact of extreme events. The present work analyzes the resilience of a Mediterranean mountain ecosystem after an extreme drought in 2005, examining shoot-growth and needle-length resistance and resilience of dominant tree and shrub species (Pinus sylvestris vs Juniperus communis, and P. nigra vs J. oxycedrus in two contrasting altitudinal ranges. Recorded high vegetative-resilience values indicate great tolerance to extreme droughts for the dominant species of pine-juniper woodlands. Observed tolerance could act as a stabilizing mechanism in rear range edges, such as the Mediterranean basin, where extreme events are predicted to be more detrimental and recurrent. However, resistance and resilience components vary across species, sites, and ontogenetic states: adult Pinus showed higher growth resistance than did adult Juniperus; saplings displayed higher recovery rates than did conspecific adults; and P. nigra saplings displayed higher resilience than did P. sylvestris saplings where the two species coexist. P. nigra and J. oxycedrus saplings at high and low elevations, respectively, were the most resilient at all the locations studied. Under recurrent extreme droughts, these species-specific differences in resistance and resilience could promote changes in vegetation structure and composition, even in areas with high tolerance to dry conditions.

  14. Snow breakage in a pole-sized ponderosa pine plantation ... more damage at high stand-densities

    Science.gov (United States)

    Robert F. Powers; William W. Oliver

    1970-01-01

    Damage by snow breakage to pole-sized ponderosa pine (Pinus pondvosa Laws.) increased as stand density increased. In a plantation on the west slope of California's Sierra Nevada, the tallest trees were most often broken. Thinning in the sapling stage is recommended as a preventative measure in dense plantations subject to heavy snowfall.

  15. Forest health monitoring in the Eastern Arc Mountains of Kenya and Tanzania: A baseline report on selected forest reserves

    Science.gov (United States)

    Seif Madoffe; James Mwang' ombe; Barbara O' Connell; Paul Rogers; Gerard Hertel; Joe Mwangi

    2005-01-01

    This status report presents the results of 43 permanent forest health study plots (3871 trees, saplings, and seedlings) established in 2000 and 2001 in parts of three areas of the Eastern Arc Mountains - the Taita Hills in Kenya (Ngangao and Chawia), the East Usambara Mountains (Amani Nature Reserve) and the Uluguru Mountains (Morogoro Teachers College and Kimboza) in...

  16. Are mice eating up all the pine seeds?

    Science.gov (United States)

    Rafal Zwolak; Kerry Foresman; Elizabeth Crone; Dean Pearson; Yvette Ortega

    2008-01-01

    Wildlife, even miniscule mice, can play an important role in forest regeneration and composition by consuming seeds, seedlings, and saplings. Mice can, through sheer numbers, consume a tremendous number of seeds. We wanted to learn if deer mice could affect how ponderosa pine forests regenerate after fire.

  17. The role of frugivorous birds and bats in the colonization of cloud forest plant species in burned areas in western Mexico

    Directory of Open Access Journals (Sweden)

    Rost, J.

    2015-07-01

    Full Text Available The extension of montane cloud forests in western Mexico is threatened by several disturbances that limit their extension. In this study we aim to assess the contribution of birds and bats in the dispersal and colonization of cloud–forest plants in contiguous surface–burned pine forests. We sampled seed rain and sapling establishment over one year in two surface–burned sites, which differed in the size of their closest cloud forest patch. A total of 17 plant species were found, most of which were late–successional trees, shrubs and climbers. Distance influenced the seed rain of only one dispersed taxon (Solanum sp. and had no effect on the sapling distribution of this or other plants. In turn, marked differences were found between sites, with more seeds dispersed and higher sapling density in the site that was next to the larger cloud forest patch. The role of long–distance dispersers and the existence of seed banks before fire could explain the little importance of distance from seed source on seed dispersal and sapling distribution. Nevertheless, dispersal by birds and bats before or after fire facilitates the regeneration and conservation of cloud forests in disturbed areas formerly occupied by other habitats.

  18. Regeneration of commercial tree species following silvicultural treatments in a moist tropical forest

    NARCIS (Netherlands)

    Peña Claros, M.; Peters, E.M.; Justiniano, J.; Bongers, F.J.J.M.; Blate, G.; Fredericksen, T.S.; Putz, F.E.

    2008-01-01

    Silvicultural treatments are generally performed to improve yields of commercially valuable tree species by increasing their recruitment and growth rates. In this study we analyze the effects of three different sets of silvicultural treatments on the densities and growth rates of seedlings, saplings

  19. Monitoring Insect and Disease Impacts on Rangeland Oaks in California

    Science.gov (United States)

    Tedmund J. Swiecki; Elizabeth A. Bernhardt; Arnold Richard A.

    1991-01-01

    We developed methods to assess the impacts of diseases and arthropods on sapling and mature rangeland oaks, and applied these methods at 18 sample plot locations in northern California. The impact of arthropod damage was generally rated as minor. Leafy mistletoe (Phoradendron villosum) was found on 5 percent of the rated trees. There was a slight...

  20. Descriptive statistics of tree crown condition in the North Central United States

    Science.gov (United States)

    KaDonna C. Randolph; Randall S. Morin; Jim Steinman

    2010-01-01

    The U.S. Forest Service Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes four crown condition indicators (crown dieback, crown density, foliage transparency, and sapling crown vigor) measured in Illinois, Indiana, Michigan, Minnesota, Missouri, and Wisconsin...

  1. Descriptive statistics of tree crown condition in the United States Interior West

    Science.gov (United States)

    KaDonna C. Randolph; Mike T. Thompson

    2010-01-01

    The U.S. Forest Service Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes four crown condition indicators (crown dieback, crown density, foliage transparency, and sapling crown vigor) measured in Colorado, Idaho, Nevada, Utah, and Wyoming between 1996 and...

  2. GASEOUS AMMONIA COUNTERACTS THE RESPONSE OF SCOTS PINE NEEDLES TO ELEVATED ATMOSPHERIC CARBON-DIOXIDE

    NARCIS (Netherlands)

    PEREZSOBA, M; VANDEREERDEN, LJM; STULEN, [No Value; KUIPER, PJC

    1994-01-01

    Four-year-old saplings of Scots pine (Pinus sylvestris L.) were exposed for 8 wk in controlled-environment chambers to charcoal-filtered air (FB), FA supplemented with 754 mg m(-3) (650 mu l l(-1)) CO2, FA supplemented with 100 mu g m(-3) NH3 and FA + CO2 + NH3. Elevated CO2 induced a significant

  3. Study on Woody Species Diversity in the Chestnut (Castanea sativa L.) Forests, Guilan, Iran

    Science.gov (United States)

    Poorbabaei, Hassan; Faghir, Marzia B.

    2008-01-01

    The purpose of this research was to study diversity of woody species in the Sweet chestnut (Castanea sativa L.) forests, Guilan, north of Iran. These forests are located in the Shafaroud and Emamzadeh Ebrahim regions. The Emamzadeh Ebrahim region is consisted of Visroud, Kishkhaleh, Askeh Koh, Male Lab, Doroudkhan, Galeroudkhan, Siahmazgy and Mali Anbar sites. Sampling was done in a selective manner in each site with a plot area of 50 m×50 m for tree and shrub layers and a circle 1000 m2 for tree saplings. In each plot, all trees ⩾10 cm in diameter at breast height (DBH) were identified and the DBH was measured, and shrub and tree sapling species were identified and recorded. In total, 68 sampling plots were taken using GPS device in the two regions. The results revealed that the mean richness, Simpson's index, Hill's N2, Shannon Wiener's function and N1 were higher in the Shafaroud region than other sites in tree, shrub and tree sapling layers. The highest and lowest mean values of evenness were obtained in the Kishkhaleh and Askekoh sites, respectively in tree layer, and similarly were in the Askekoh and Visroud in the shrub layer. The highest and lowest mean values of evenness were obtained in the Male Lab and Askeh Koh, respectively in the tree sapling layer.

  4. RAPD-PCR analysis of cultured type olives in Turkey | Sesli | African ...

    African Journals Online (AJOL)

    In this study, samples were obtained from the Olive Production Research Institute (Manzanilla, Domat, Gemlik and Memecik) and sapling producers in Manisa, Akhisar (Uslu, Edremit). Genomic DNA's were extracted from young leaves and PCR was used generate RAPD bands. Sixty random primers obtained from Operon ...

  5. Effects of some humidity and IBA hormone dose applicatıons on ...

    African Journals Online (AJOL)

    USER

    2010-04-26

    Apr 26, 2010 ... ratio of cutting callus formation was found in control group (58%) in 95 - 100% humidity level and 2500 ppm IBA hormone dose ... Key words: M9, sooftwood top cutting, misting system, humidity, hormone, rooting. INTRODUCTION. Anatolia ... Turkey produced about 6 million pieces of apple saplings in 2007 ...

  6. Interpreting Recruitment Limitation in Forests

    Science.gov (United States)

    J.S. Clark; B. Beckage; P. Camill; B. Cleveland; J. HilleRisLambers; J. Lichter; J. McLachlan; J. Mohan; P. Wyckoff

    1999-01-01

    Studies of tree recruitment are many, but they provide few general insights into the role of recruitment limitation for population dynamics. That role depends on the vital rates (transitions) from seed production to sapling stages and on overall population growth. To determine the state of our understanding of recruitment limitation we examined how well we can estimate...

  7. The Effect of Land Use Changes on Blue Oak Regeneration and Recruitment

    Science.gov (United States)

    Scott Mensing

    1991-01-01

    Lack of blue oak (Quercus douglasii) saplings and seedlings throughout much of its range has prompted research into the regeneration status of the species. Our ability to assess whether the current lack of regeneration is a natural pattern or a response to human induced environmental change is limited by lack of data on the history of blue oak...

  8. Stem-righting mechanism in gymnosperm trees deduced from limitations in compression wood development.

    Science.gov (United States)

    Yamashita, Saori; Yoshida, Masato; Takayama, Shozo; Okuyama, Takashi

    2007-03-01

    In response to inclination stimuli, gymnosperm trees undergo corrective growth during which compression wood develops on the lower side of the inclined stem. High compressive growth stress is generated in the compression wood region and is an important factor in righting the stem. The aims of the study were to elucidate how the generation of compressive growth stress in the compression wood region is involved in the righting response and thus to determine a righting mechanism for tree saplings. Cryptomeria japonica saplings were grown at inclinations of 0 degrees (vertical) to 50 degrees. At each inclination angle, the growth stress on the lower side of the inclined stem was investigated, together with the degree of compression-wood development such as the width of the current growth layer and lignin content, and the upward bending moment. Growth stress, the degree of compression wood development, and the upward moment grew as the stem inclination angle increased from 0 to 30 degrees, but did not rise further at inclinations > 30 degrees. The results suggest the following righting mechanism for gymnosperm saplings. As the stem inclination is elevated from 0 to 30 degrees, the degree of compression wood development increases to force the sapling back to its original orientation; at inclinations > 30 degrees, the maximum degree of compression wood is formed and additional time is needed for the stem to reorient itself.

  9. Descriptive statistics of tree crown condition in California, Oregon, and Washington

    Science.gov (United States)

    KaDonna C. Randolph; Sally J. Campbell; Glenn Christensen

    2010-01-01

    The U.S. Forest Service Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes four tree crown condition indicators (crown dieback, crown density, foliage transparency, and sapling crown vigor) measured in California, Oregon, and Washington between 1996 and 1999....

  10. Effects of reindeer on the re-establishment of Betula pubescens subsp. czerepanovii and Salix phylicifolia in a subarctic meadow

    Directory of Open Access Journals (Sweden)

    Michael den Herder

    2003-04-01

    Full Text Available The effect of reindeer browsing on the regeneration of Betula pubescens subsp. czerepanovii and Salix phylicifolia was studied in a subarctic meadow in Finnish Lapland. The aim of the study was to see whether tree recovery from seeds is possible under heavy reindeer-browsing pressure. After removal of the ground and field layer vegetation in 1986, two exclosures were established so that the effect of reindeer on the secondary succession, starting from seeds, could be studied. The size and the number of B. pubescens and S. phylicifolia were recorded in 1994, 1996, 1997 and 1999. Reindeer significantly reduced the height and the number of saplings (plants > 10 cm high of B. pubescens and S. phylicifolia but the number of seedlings (plants < 10 cm high did not differ between browsed and unbrowsed plots. Furthermore the heightclass distribution of saplings was different inside the exlosures compared to control areas. Over time browsed plots continued to have high densities of small saplings while in protected plots an increasing number of larger saplings appeared. In our study site, regeneration from seeds seemed possible although the height of B. pubescens and S. phylicifolia was limited by reindeer. 

  11. Composition, structure, and dynamics of the Illinois Ozark Hills Forest

    Science.gov (United States)

    Lisa M. Helmig; James S. Fralish

    2011-01-01

    In the mature oak-hickory ecosystem of the Illinois Ozark Hills, forest community composition, dynamics, and structure were studied to examine the extent of conversion to mesophytic species and eventually predict the broad threshold time of complete conversion. Tree, sapling, and seedling data were collected from 87 plots distributed throughout the region. Data for the...

  12. Scaling relationship between tree respiration rates and biomass.

    Science.gov (United States)

    Cheng, Dong-Liang; Li, Tao; Zhong, Quan-Lin; Wang, Gen-Xuan

    2010-10-23

    The WBE theory proposed by West, Brown and Enquist predicts that larger plant respiration rate, R, scales to the three-quarters power of body size, M. However, studies on the R versus M relationship for larger plants (i.e. trees larger than saplings) have not been reported. Published respiration rates of field-grown trees (saplings and larger trees) were examined to test this relationship. Our results showed that for larger trees, aboveground respiration rates RA scaled as the 0.82-power of aboveground biomass MA, and that total respiration rates RT scaled as the 0.85-power of total biomass MT, both of which significantly deviated from the three-quarters scaling law predicted by the WBE theory, and which agreed with 0.81-0.84-power scaling of biomass to respiration across the full range of measured tree sizes for an independent dataset reported by Reich et al. (Reich et al. 2006 Nature 439, 457-461). By contrast, R scaled nearly isometrically with M in saplings. We contend that the scaling exponent of plant metabolism is close to unity for saplings and decreases (but is significantly larger than three-quarters) as trees grow, implying that there is no universal metabolic scaling in plants.

  13. JPRS Report, East Asia, Southeast Asia.

    Science.gov (United States)

    1988-04-19

    wearing slippers and jeans, now holds court in a big run-down house with the paint peeling from the walls. Guards stand at the doors, watching the... mango saplings in their new hectares, but EZ hates to see them go to waste. He eventually gives in. "What can I do? It’s their land now," he says

  14. Ja-nua-rY

    Indian Academy of Sciences (India)

    Work is going on towards developing low energy positron and electron accelerators and ion implanter, preparation of Mossbauer sources and sa~ple preparation for various experiments like PIXE, biosciences and atomic absorption spectrometry. A full fledged target preparation laboratory for nuclear physics experiments ...

  15. The central Appalachian hardwoods experience provides silvicultural tools for Ontario

    Science.gov (United States)

    Gary W. Miller; Ken A Elliott; Eric P. Boysen

    1998-01-01

    Cultural practices can be applied in even-age stands to reallocate site resources to selected crop trees. Precommercial thinning in sapling stands can increase diameter growth and improve species composition of trees in the main canopy. Commercial thinning in sawtimber stands also increases diameter growth of crop trees, improves residual stand quality, and removes...

  16. Effect of crown growing space and age on the growth of northern red oak

    Science.gov (United States)

    Gary W. Miller

    1997-01-01

    Cultural practices can be applied in even-age stands to reallocate site resources to selected crop trees. Precornrnercial thinning in sapling stands can increase diameter growth and improve species composition of trees in the main canopy. Commercial thinning in sawtimber stands also increases diameter growth of crop trees, improves residual stand quality, and removes...

  17. Growth of California red fir advance regeneration after overstory removal and thinning

    Science.gov (United States)

    William W. Oliver

    1985-01-01

    Advance regeneration is common under decadent, old-growth stands of California red fir (Abies magnifica A. Murr.). Intense competition for the site's resources can create sapling stands of poor vigor and advanced age. When competition is reduced by overstory removal and thinning, suppressed advance regeneration has been shown to respond with...

  18. Forest research notes, Pacific Northwest Forest Experiment Station, No. 33, January 24, 1945.

    Science.gov (United States)

    Thornton T. Munger; Leo A. Isaac; William G. Morris

    1945-01-01

    The stocked quadrat concept of classifying land according to its degree of reforesting has largely replaced the method of classifying land according to the number of seedlings or saplings per acre. However, questions are asked frequently concerning the technique of employing this method and concerning the relationship, between the stocked quadrat classes and the number...

  19. Response of dwarf mistletoe-infested ponderosa pine to thinning: 2. Dwarf mistletoe propagation.

    Science.gov (United States)

    Lewis F. Roth; James W. Barrett

    1985-01-01

    Propagation of dwarf mistletoe in ponderosa pine saplings is little influenced by thinning overly dense stands to 250 trees per acre. Numerous plants that appear soon after thinning develop from formerly latent plants in the suppressed under-story. Subsequently, dwarf mistletoe propagates nearly as fast as tree crowns enlarge but the rate differs widely among trees....

  20. Northern white-cedar ecology and silviculture in the northeastern United States and southeastern Canada: a synthesis of knowledge

    Science.gov (United States)

    Philip V. Hofmeyer; Laura S. Kenefic; Robert S. Seymour

    2009-01-01

    Sustainability of the northern white-cedar (Thuja occidentalis L.) resource is a concern in many regions throughout its range because of regeneration failures, difficulty recruiting seedlings into sapling and pole classes, and harvesting levels that exceed growth. Management confusion has resulted from the scarcity of research on northern white-cedar...

  1. Tree crown conditions in Missouri, 2000-2003

    Science.gov (United States)

    KaDonna C. Randolph; W. Keith Moser

    2009-01-01

    The Forest Service, U.S. Department of Agriculture, Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes three FIA tree crown condition indicators (crown dieback, crown density, and foliage transparency) and sapling crown vigor measured in Missouri between 2000...

  2. Descriptive statistics of tree crown condition in the Northeastern United States

    Science.gov (United States)

    KaDonna C. Randolph; Randall S. Morin; Jim Steinman

    2010-01-01

    The U.S. Forest Service Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes four crown condition indicators (crown dieback, crown density, foliage transparency, and sapling crown vigor) measured in Connecticut, Delaware, Maine, Maryland, Massachusetts, New...

  3. Burlington Northern Taconite Transshipment Facility, Duluth-Superior Harbor, Superior Wisconsin. Environmental Assessment Report.

    Science.gov (United States)

    1975-03-01

    characterized by white birch-balsam fir association. The dominant understory is once again currant and blue grass; however, ferns were abundant, indicating a...formerly used for coal stockpiling and includes areas with willow saplings, aster, golden - rod and dense grasses. This vegetation would be smothered

  4. Ozone-induced H2O2 accumulation in field-grown aspen and birch is linked to foliar ultrastructure and peroxisomal activity

    Science.gov (United States)

    E. Oksanen; E. Häikiö; J. Sober; D.F. Karnosky

    2003-01-01

    Saplings of three aspen (Populus tremuloides) genotypes and seedlings of paper birch (Betula papyrifera) were exposed to elevated ozone (1.5x ambient) and 560 p.p.m. CO2, singly and in combination, from 1998 at the Aspen-FACE (free-air CO2 enrichment) site (Rhinelander, USA).

  5. Diversity and composition of understory vegetation in the tropical seasonal rain forest of Xishuangbanna, SW China.

    Science.gov (United States)

    Lü, Xiao-Tao; Yin, Jiang-Xia; Tang, Jian-Wei

    2011-03-01

    Tropical forests vegetation and community research have tended to focus on the tree component, and limited attention has been paid to understory vegetation. Species diversity and composition of the understory of tropical seasonal rain forest were inventoried in a 625 m2 area (for sapling layer) and a 100 m2 area (for herb/seedling layer) in three 1 ha plots. We found 3068 individuals belonging to 309 species, 192 genera and 89 families. The most important family as determined by the Family Importance Value (FIV) was Rubiaceae in both sapling and herb/seedling layers. In terms of Importance Value Index (IVI), the shrub Mycetia gracilis (Rubiaceae) was the most important species in the sapling layer and the pteridophyte Selaginella delicatula (Selaginellaceae) was the most ecological significant species in the herb/seedling layer. Much more vascular plant species were registered in the understory than in the tree layer totaled among the three plots. The species diversity did not differ significantly among the tree layer, sapling layer and herb/seedling layer. Given that we still know little about the understory plant community for growth forms other than trees, the results from the present study indicate that more attention should be paid to the understory vegetation during the decision-making process for biodiversity conservation in the tropical forests.

  6. Diversity and composition of understory vegetation in the tropical seasonal rain forest of Xishuangbanna, SW China

    Directory of Open Access Journals (Sweden)

    Lü Xiao-Tao

    2011-03-01

    Full Text Available Tropical forests vegetation and community research have tended to focus on the tree component, and limited attention has been paid to understory vegetation. Species diversity and composition of the understory of tropical seasonal rain forest were inventoried in a 625m² area (for sapling layer and a 100m² area (for herb/seedling layer in three 1ha plots. We found 3068 individuals belonging to 309 species, 192 genera and 89 families. The most important family as determined by the Family Importance Value (FIV was Rubiaceae in both sapling and herb/seedling layers. In terms of Importance Value Index (IVI, the shrub Mycetia gracilis (Rubiaceae was the most important species in the sapling layer and the pteridophyte Selaginella delicatula (Selaginellaceae was the most ecological significant species in the herb/seedling layer. Much more vascular plant species were registered in the understory than in the tree layer totaled among the three plots. The species diversity did not differ significantly among the tree layer, sapling layer and herb/seedling layer. Given that we still know little about the understory plant community for growth forms other than trees, the results from the present study indicate that more attention should be paid to the understory vegetation during the decision-making process for biodiversity conservation in the tropical forests. Rev. Biol. Trop. 59 (1: 455-463. Epub 2011 March 01.

  7. The role of biocontrol of emerald ash borer in protecting ash regeneration after invasion

    Science.gov (United States)

    Jian J. Duan; Roy G. Van Driesche; Leah S. Bauer; Richard Reardon; Juli Gould; Joseph S. Elkinton

    2017-01-01

    Long-term monitoring in Michigan and several northeastern states has documented increasing parasitism and reduced EAB attack rates. Ash regeneration is currently benefiting from releases of introduced parasitoids, which now cause 20-80% parasitism of EAB larvae in ash saplings (1-2 inch dia.) and young trees (5-8 inch dia.).

  8. Perception of Agricultural Extension as a Career among ...

    African Journals Online (AJOL)

    The study investigated perception of agricultural extension as a career among postgraduateagricultural students in selected universities in south-west, Nigeria. Multi-stage sapling technique was used to select 171 respondents across three universities. Data were analyzed using both descriptive and inferential statistics ...

  9. Selection Management in Southern Appalachian Hardwoods

    Science.gov (United States)

    Lino Della-Bianca; Donald E. Beck

    1985-01-01

    A woodland tract of southern Appalachian cove hardwoods and mixed oak has been managed under the selection satem of silviculture since 1946.Simply cutting in all commercial diameter classes (i.e. 6.0 inches and larger), as was the practice during the first 24 years, failed to develop enough desirable saplings and poles to maintain the system.After 1970,...

  10. Early genetic evaluation of open-pollinated Douglas-fir families

    Science.gov (United States)

    Kurt H. Riitters; David A. Perry

    1987-01-01

    In a test of early genetic evaluation of the growth potential of 14 families of open-pollinated Douglas-fir (Pseudotsuga menziesii) [Mirb.] Franco), measures of growth and phenology of seedligns grown in a coldframe were correlated with height of saplings in evaluation plantations at 9, 12, and 15 years. fifteen-year height was most strongly...

  11. Community organization of tree species along soil gradients in a north-eastern USA forest

    NARCIS (Netherlands)

    Bigalow, S.W.; Canham, C.D.

    2002-01-01

    1 A study was carried out in oak-northern hardwood forest in NW Connecticut USA involving measurements of growth, light and soil environment of saplings of six canopy trees that are strongly associated with particular soil types as adults. The objectives were to determine patterns of growth response

  12. Effects of visual silhouette, leaf size and host species on feeding preference by adult emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)

    Science.gov (United States)

    Deepa S. Pureswaran; Therese M. Poland

    2009-01-01

    The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive species recently established in North America. In large arena bioassays, when given a choice among live green ash, Fraxinus pennsylvanica Marsh and artificial ash saplings that were hidden or exposed from view, beetles preferred live...

  13. Is differential use of Juniperus monosperma by small ruminants driven by terpenoid concentration?

    Science.gov (United States)

    Estell, R E; Utsumi, S A; Cibils, A F; Anderson, D M

    2014-03-01

    Differential plant use by herbivores has been observed for several woody plant species and has frequently been attributed to plant secondary metabolites. We examined the relationship between terpenoid concentration and Juniperus monosperma herbivory by small ruminants. Two groups of animals (10 goats or 5 goats plus 4 sheep) browsed 16 paddocks (20 × 30 m) containing one-seed juniper for six days during two seasons. Juniper leaves were sampled from 311 saplings immediately after browsing. Saplings were categorized by size (short [1.0 m]), and by browsing intensity (light [66 %]). Juniper bark was collected from 12 saplings during spring. Total estimated terpenoid concentrations in leaves and bark were 18.3 ± 0.3 and 8.9 ± 0.8 mg/g, respectively, and the dominant terpene in both tissues was α-pinene (11.1 ± 0.2 and 7.6 ± 0.7 mg/g, respectively). Total terpenoid concentration of juniper leaves was greater in spring than summer (20.6 ± 0.5 vs. 16.7 ± 0.3 mg/g, respectively) and was lower in short saplings than medium or tall saplings (16.5 ± 0.6 vs. 19.8 ± 0.4 and 19.5 ± 0.4 mg/g, respectively). Total terpenoid concentration of leaves also differed among the three defoliation categories (21.2 ± 0.6, 18.7 ± 0.5, and 16.1 ± 0.4 mg/g for light, moderate, and heavy, respectively). The smallest subset of terpenoids able to discriminate between light and heavy browsing intensity categories included eight compounds ([E]-β-farnesene, bornyl acetate, γ-eudesmol, endo-fenchyl acetate, γ-cadinene, α-pinene, cis-piperitol, and cis-p-menth-2-en-1-ol). Our results suggest terpenoid concentrations in one-seed juniper are related to season, sapling size, and browsing by small ruminants.

  14. Observations on natural regeneration in grazed Holm oak stands in the Ogliastra province (Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    Sioni S

    2011-07-01

    Full Text Available This paper deals with the effects of grazing pressure in two Holm oak (Quercus ilex stands in Ogliastra (central-eastern Sardinia, Italy, with particular reference to the interactions with the natural regeneration processes. There is a positive interaction (facilitation between shrubs and seedlings of tree species, as observed in other similar studies carried out by the same authors in other areas of Sardinia. Rubus ulmifolius proved to be the most efficient shrub for the protection and growth of saplings; the other shrub species play a less marked facilitating role. Although the density of shrubs hosting Holm oak seedlings is fairly high, their age and small size confirm that the current grazing pressure is incompatible with any chance of growth of the saplings and success of the natural regeneration. The conservation of these stands must therefore rely on the rationalisation of human activities through the exploitation of a whole range of resources.

  15. A Simple Planting Technique for Re-establishing Trees Where Frequent Inundation Occurs.

    Science.gov (United States)

    Dreschel, Thomas W; Cline, Eric A

    2018-01-26

    Many of the Everglades tree islands have lost elevation over the past century and most of their trees have died such that they are now covered with herbaceous plants. This protocol describes a simple, cost-effective tree planting technique needed for restoring degraded Everglade tree islands. The design is patterned after a natural Everglades process that creates floating peat islands, which allows tree survival and growth in flooded conditions and often leads to the development of tree islands. Commercially available peat bags were used as the medium for the growth and establishment of potted native tree saplings. The pop-up configuration floated initially and provided additional elevation to minimize inundation, with a single native tree species sapling and a single tree fertilizer spike. During a 3 year study involving 105 pop-ups, most plants survived (80%) and many thrived. Determining whether this technique can establish trees on a degraded tree island will require longer studies and extensive field tests.

  16. Tree Species Establishment in Urban Forest in Relation to Vegetation Composition, Tree Canopy Gap Area and Soil Factors

    Directory of Open Access Journals (Sweden)

    Ilze Jankovska

    2015-12-01

    Full Text Available The study of density and growth of pine, birch and oak seedlings and saplings in canopy gaps in the urban boreal forest in Riga, Latvia, indicates that natural regeneration can increase diversity in small gaps caused by tree mortality, and can ensure conversion from even-aged pine forest. Abundant regeneration in small gaps showed that light (gap area was only one of the factors affecting tree regeneration in the gaps. The depth of the O layer and pH were suggested to be important factors for the establishment and growth of pine and birch. For oak, the main factors for establishment and growth were favorable moisture, higher pH and N concentration. Knowledge of ecological factors affecting the establishment of seedlings and growth of saplings of the most common trees species in the urban boreal forest is needed to predict successional trajectories and to aid management.

  17. Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, P.J.

    2001-09-04

    This numeric data package provides data sets, and accompanying documentation, on site characterization, system performance, weather, species composition, and growth for the Throughfall Displacement Experiment, which was established in the Walker Branch Watershed of East Tennessee to provide data on the responses of forests to altered precipitation regimes. The specific data sets include soil water content and potential, coarse fraction of the soil profile, litter layer temperature, soil temperature, monthly weather, daily weather, hourly weather, species composition of trees and saplings, mature tree and sapling annual growth, and relative leaf area index. Fortran and SAS{trademark} access codes are provided to read the ASCII data files. The data files and this documentation are available without charge on a variety of media and via the Internet from the Carbon Dioxide Information Analysis Center (CDIAC).

  18. Influence of solar UV radiation on the nitrogen metabolism in needles of Scots pine (Pinus sylvestris L.).

    Science.gov (United States)

    Krywult, Marek; Smykla, Jerzy; Kinnunen, Heli; Martz, Françoise; Sutinen, Marja-Liisa; Lakkala, Kaisa; Turunen, Minna

    2008-12-01

    Needles of 20-year-old Scots pine (Pinus sylvestris L.) saplings were studied in an ultraviolet (UV) exclusion field experiment (from 2000 to 2002) in northern Finland (67 degrees N). The chambers held filters that excluded both UV-B and UV-A, excluded UV-B only, transmitted all UV (control), or lacked filters (ambient). UV-B/UV-A exclusion decreased nitrate reductase (NR) activity of 1-year-old needles of Scots pines compared to the controls. The proportion of free amino acids varied in the range 1.08-1.94% of total proteins, and was significantly higher in needles of saplings grown under UV-B/UV-A exclusion compared to the controls or UV-B exclusion. NR activity correlated with air temperature, indicating a "chamber effect". The study showed that both UV irradiance and increasing temperature are significant modulators of nitrogen (N) metabolism in Scots pine needles.

  19. Vegetation Characteristics of the Orangutan (Pongo pygmaeus morio Habitat in the Riparian Forest of Menamang, East Kalimantan

    Directory of Open Access Journals (Sweden)

    Tri Sayektiningsih

    2017-06-01

    Full Text Available This study aimed to obtain information on vegetation characteristics of the orangutan’s habitat, including diversity, composition and structure, in the riparian forest of Menamang. Data was collected using a line-plot sampling method. The diversity index of trees and saplings was higher than seedlings. It was found that Lagestroemia speciosa showed the highest value of IVI at tree stage, accounted for 24.71 %. Fordia splendidissima then was dominant species at sapling stage with IVI of 29.94 %. Furthermore, Pterospermum diversifolium grew in abundance at seedling stage with IVI of 26.87 %. Overall, vegetation in the research location was consisted by relatively young trees characterized by the abundance of trees with diameter of ≥ 10 - 20 cm and height of < 15 m.

  20. CEPF Western Ghats Special Series Ecology, distribution and population status of Elaeocarpus venustus Bedd. (Oxalidales: Elaeocarpaceae, a threatened tree species from Agasthiyamalai Biosphere Reserve, southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    S.J. Irwin

    2013-05-01

    Full Text Available This paper deals with the ecology, population size, status of regeneration, habitat degradation and threat status of Elaeocarpus venustus Bedd. An endemic and threatened tree species restricted to Agasthiyamalai Biosphere Reserve, southern Western Ghats, India. The population sites of this species in the study area were recorded using Global Positioning System and mapped using Arc GIS software. The population of this species is highly fragmented due to anthropogenic activities. The total stem count in all population sites from the study area was carried out to understand the population structure. A total of 181 saplings were recorded from the entire study area of which 180 are from a single site. Nearly 64% of the stems recorded in this study are mature stems. Poor regeneration was seen in population sites that were highly disturbed. In spite of good adult population, the low number of saplings shows poor germination of seeds and establishment of seedlings.

  1. Report on Progress Toward Security and Stability in Afghanistan: United States Plan for Sustaining the Afghanistan National Security Forces

    Science.gov (United States)

    2012-04-01

    plant more than 1 million fruit tree saplings; and 3) distribution of vegetable seed and fertilizer conditional asset transfers to approximately 1,000...Russian Federal Drug Control Service, the State Drug Control Service of Kyrgyzstan , and the Tajikistan Drug Control Agency. The most recent meeting was...Uzbekistan, Tajikistan, Kyrgyzstan , and Turkmenistan. 106 functioned as the primary sustainment routes into Afghanistan, increased in importance

  2. Tree demography suggests multiple directions and drivers for species range shifts in mountains of Northeastern United States.

    Science.gov (United States)

    Wason, Jay W; Dovciak, Martin

    2017-08-01

    Climate change is expected to lead to upslope shifts in tree species distributions, but the evidence is mixed partly due to land-use effects and individualistic species responses to climate. We examined how individual tree species demography varies along elevational climatic gradients across four states in the northeastern United States to determine whether species elevational distributions and their potential upslope (or downslope) shifts were controlled by climate, land-use legacies (past logging), or soils. We characterized tree demography, microclimate, land-use legacies, and soils at 83 sites stratified by elevation (~500 to ~1200 m above sea level) across 12 mountains containing the transition from northern hardwood to spruce-fir forests. We modeled elevational distributions of tree species saplings and adults using logistic regression to test whether sapling distributions suggest ongoing species range expansion upslope (or contraction downslope) relative to adults, and we used linear mixed models to determine the extent to which climate, land use, and soil variables explain these distributions. Tree demography varied with elevation by species, suggesting a potential upslope shift only for American beech, downslope shifts for red spruce (more so in cool regions) and sugar maple, and no change with elevation for balsam fir. While soils had relatively minor effects, climate was the dominant predictor for most species and more so for saplings than adults of red spruce, sugar maple, yellow birch, cordate birch, and striped maple. On the other hand, logging legacies were positively associated with American beech, sugar maple, and yellow birch, and negatively with red spruce and balsam fir - generally more so for adults than saplings. All species exhibited individualistic rather than synchronous demographic responses to climate and land use, and the return of red spruce to lower elevations where past logging originally benefited northern hardwood species indicates

  3. Changes in monoterpene emission rates of Quercus ilex infested by aphids tended by native or invasive Lasius ant species.

    Science.gov (United States)

    Paris, Carolina I; Llusia, Joan; Peñuelas, Josep

    2010-07-01

    The emission of volatile organic compounds (VOCs) depends on temperature and light. Other factors such as insect herbivory also may modify VOC emission. In particular, aphid feeding promotes the release of new compounds and changes the composition of plant volatile blends. Given that some aphids are tended by ants, we investigated whether ants change the emission of VOCs indirectly through attendance on aphids. The effect of Lachnus roboris aphids and two different tending ant species on terpene emission rates of 4-year-old holm oak (Quercus ilex) saplings was investigated during a field experiment. There were five treatments: saplings alone (T1), saplings infested with L. roboris aphids (T2), saplings infested with aphids tended by the local ant Lasius grandis (T3), those tended by small colonies of the invasive ant Lasius neglectus (T4), and those tended by large colonies of the same invasive ant species (T5). The infestation by L. roboris elicited the emission of Delta(3)-carene and increased the emission of myrcene and gamma-terpinene. Terpene emissions were modified depending on the tending ant species. Attendance by the local ant L. grandis increased alpha and beta-pinene and sabinene. Attendance by the invasive ant L. neglectus only decreased significantly the emission of myrcene, one of the major compounds of the Q. ilex blend. Aphid abundance decreased with time for all treatments, but there was no difference in aphid abundance among treatments. Total terpene emission rates were not correlated with aphid abundance. These results highlight that aphids and tending ants may change terpene emission rates, depending on the ant species.

  4. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Atlantic and Gulf Coastal Plain Region (Version 2.0)

    Science.gov (United States)

    2010-11-01

    and outer portions of the coastal plain, common species include American beech (Fagus grandifolia), sweetgum ( Liquidambar styraciflua), southern...15.0% 20% of total cover = 6.0% Sapling Acer rubrum Liquidambar styraciflua Fraxinus pennsylvanica FAC FAC FACW 9 9 2 Yes Yes...No Total cover 20 50/20 Thresholds: 50% of total cover =10.0% 20% of total cover = 4.0% Tree Acer rubrum Liquidambar styraciflua

  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. Invasive insect effects on nitrogen cycling and host physiology are not tightly linked.

    Science.gov (United States)

    Rubino, Lucy; Charles, Sherley; Sirulnik, Abby G; Tuininga, Amy R; Lewis, James D

    2015-02-01

    Invasive insects may dramatically alter resource cycling and productivity in forest ecosystems. Yet, although responses of individual trees should both reflect and affect ecosystem-scale responses, relationships between physiological- and ecosystem-scale responses to invasive insects have not been extensively studied. To address this issue, we examined changes in soil nitrogen (N) cycling, N uptake and allocation, and needle biochemistry and physiology in eastern hemlock (Tsuga canadensis (L) Carr) saplings, associated with infestation by the hemlock woolly adelgid (HWA) (Adelges tsugae Annand), an invasive insect causing widespread decline of eastern hemlock in the eastern USA. Compared with uninfested saplings, infested saplings had soils that exhibited faster nitrification rates, and more needle (15)N uptake, N and total protein concentrations. However, these variables did not clearly covary. Further, within infested saplings, needle N concentration did not vary with HWA density. Light-saturated net photosynthetic rates (Asat) declined by 42% as HWA density increased from 0 to 3 adelgids per needle, but did not vary with needle N concentration. Rather, Asat varied with stomatal conductance, which was highest at the lowest HWA density and accounted for 79% of the variation in Asat. Photosynthetic light response did not differ among HWA densities. Our results suggest that the effects of HWA infestation on soil N pools and fluxes, (15)N uptake, needle N and protein concentrations, and needle physiology may not be tightly coupled under at least some conditions. This pattern may reflect direct effects of the HWA on N uptake by host trees, as well as effects of other scale-dependent factors, such as tree hydrology, affected by HWA activity. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Forest structure, diversity and regeneration potential along altitudinal gradient in Dhanaulti of Garhwal Himalaya

    Directory of Open Access Journals (Sweden)

    Sushil Saha

    2016-07-01

    Full Text Available Aim of the study: The aim of the present study was to understatnd the forest composition, structure, diversity and regeneration potential along altitudinal gradient. Area of study: The study was carried out in Dhanaulti forest which falls under temperate region of Garhwal Himalaya in Uttarakhand state, India. Material and Methods: Vegetation analysis was carried out using 10 quadrats at each altitude using a quadrate size of 10×10 m2. In each quadrate, categories of trees >30 cm cbh were considered as trees, 10-30cm cbh as saplings and <10 cm cbh as seedlings. The data were quantitatively analyzed. Main results: In upper and middle altitudes, Cedrus deodara was reported dominant tree whereas, in lower altitude Quercus leucotrichophora was reported dominant. Tree density was highest in lower altitude which reduced middle and upper altitudes whereas, total basal cover increased with increasing altitude. The increasing total basal cover with altitude could be because of the presence of Cedrus deodara trees having higher girth classes. In tree, sapling and seedling layers, diversity (H and equitabiltiy (EC decreased with increasing altitude. However, concentrations of dominace (CD and beta diversity (BD have shown reverse trend with H and EC which increased with increasing altitudes, in each layer of tree, sapling and seedling. The distribution pattern of most species in all layers of trees, saplings and seedlings was contagious. The regeneration potential of the species has shown that some of the species in the absence of tree layer are still regenerating particularly, Rhododendron arboreum, Benthamidia capitata, Neolitsea pallens etc. It indicates that most of the species are shifting upward as they are getting suitable conditions. Research highlights: Altitude influence species composition, diversity and regeneration potential of species. Key words: Distribution pattern; tree diversity; regeneration; mountains; temperate; Himalaya.

  8. Forest structure, diversity and regeneration potential along altitudinal gradient in Dhanaulti of Garhwal Himalaya

    Energy Technology Data Exchange (ETDEWEB)

    Saha, S.; Rajwar, G.S.; Kumar, M.

    2016-07-01

    Aim of the study: The aim of the present study was to understatnd the forest composition, structure, diversity and regeneration potential along altitudinal gradient. Area of study: The study was carried out in Dhanaulti forest which falls under temperate region of Garhwal Himalaya in Uttarakhand state, India. Material and Methods: Vegetation analysis was carried out using 10 quadrats at each altitude using a quadrate size of 10×10 m2. In each quadrate, categories of trees >30 cm cbh were considered as trees, 10-30cm cbh as saplings and <10 cm cbh as seedlings. The data were quantitatively analyzed. Main results: In upper and middle altitudes, Cedrus deodara was reported dominant tree whereas, in lower altitude Quercus leucotrichophora was reported dominant. Tree density was highest in lower altitude which reduced middle and upper altitudes whereas, total basal cover increased with increasing altitude. The increasing total basal cover with altitude could be because of the presence of Cedrus deodara trees having higher girth classes. In tree, sapling and seedling layers, diversity (H) and equitabiltiy (EC) decreased with increasing altitude. However, concentrations of dominace (CD) and beta diversity (BD have shown reverse trend with H and EC which increased with increasing altitudes, in each layer of tree, sapling and seedling. The distribution pattern of most species in all layers of trees, saplings and seedlings was contagious. The regeneration potential of the species has shown that some of the species in the absence of tree layer are still regenerating particularly, Rhododendron arboreum, Benthamidia capitata, Neolitsea pallens etc. It indicates that most of the species are shifting upward as they are getting suitable conditions. Research highlights: Altitude influence species composition, diversity and regeneration potential of species. (Author)

  9. Morphometry of the hard palate in Down's syndrome through CBCT-image analysis.

    Science.gov (United States)

    Abeleira, M T; Outumuro, M; Diniz, M; Limeres, J; Ramos, I; Diz, P

    2015-11-01

    To define the morphometry of the hard palate in Down's syndrome (DS) on cone beam computed tomography (CBCT) images. Santiago de Compostela University (Spain). The study group included 40 white DS individuals aged 10 to 40 years (mean = 18.8 ± 7.3 years), 25 males and 15 females. The control group consisted of 40 individuals matched for age and sex were selected. Nine measurements were taken on the CBCT images. Axial plane: anteroposterior length (aAPL) and arch length (aARL); sagittal plane: anteroposterior length (sAPL), maximum height (sMH) and sagittal arch (sAR); coronal plane: interdental width (cIDW), height (cHE), skeletal width (cSW) and coronal arch (cAR). aAPL, aARL, sAPL, sMH, sAR, cMH and cAR were comparable in the two groups. cIDW and cSW were greater in controls than in DS. We found no statistically significant differences between males and females with DS. In the controls, sAPL and sAR were greater in males than females. In DS, age only had a statistically significantly increasing effect on aAPL and sAPL. In the controls, age significantly affected sAR and cHE. The hard palate is narrower in DS than in controls, but the anteroposterior measurements and the height of the vault are comparable in both groups. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Is the use of cuttings a good proxy to explore phenological responses of temperate forests in warming and photoperiod experiments?

    Science.gov (United States)

    Vitasse, Yann; Basler, David

    2014-02-01

    For obvious practical reasons, tree phenological data obtained in warming and photoperiod experiments are generally conducted on juvenile trees (saplings and seedlings) or on watered or rooted cuttings collected from adult trees. As juvenile trees differ from adult trees in their phenological response to environmental conditions, they represent inappropriate plant material to experimentally assess the phenological responses of forests to seasonality. Cuttings are physiologically closer to adult trees, but cutting itself and the disruption of hormonal signals may create artefacts. This study aimed to investigate the potential deviation between phenological responses of cuttings vs donor trees. We hypothesized that, once dormant, buds may respond autonomously to environmental influences such as chilling, photoperiod and warming, and, thus, cuttings may exhibit similar phenological responses to mature trees. We compared bud development of seedlings, saplings and mature trees of three deciduous tree species with bud development of cuttings that were excised from both saplings and adults and positioned in situ in the vicinity of adult trees within a mature mixed forest in the foothills of the Swiss Jura Mountains. No significant difference was detected in the timing of bud burst between cuttings and donor trees for the three studied tree species when the vertical thermal profile was accounted for. However, a significant difference in the timing of flushing was found between seedlings, saplings and adults, with earlier flushing during the juvenile stage. At least for the three studied species, this study clearly demonstrates that cuttings are better surrogates than juvenile trees to assess potential phenological responses of temperate forests to climate change in warming and photoperiod experiments.

  11. Buds enable pitch and shortleaf pines to recover from injury

    Science.gov (United States)

    S. Little; H. A. Somes

    1956-01-01

    Pitch and shortleaf pines often survive severe damage by fires, cutting, rabbits, or deer. Deer may take all but 2 inches of the 6- to 8-inch shoots of seedlings, and still these seedlings may live and develop new shoots. Fires may kill all the foliage and terminal shoots on sapling or pole-size stems, but still these trees may green up and develop new leaders. Many of...

  12. Crop-tree release increases growth of 12-year-old yellow-poplar and black cherry

    Science.gov (United States)

    Neil I. Lamson; H. Clay. Smith; H. Clay. Smith

    1989-01-01

    Precommercial thinning was done in a 12-year-old Appalachian hardwood sapling stand in West Virginia. Two crop-tree release techniques were used--crown touching and crown touching plus 5 feet. Results indicated that both treatments significantly increased 5-year d.b.h. growth for released yellow-poplar and black cherry crop trees. Although there was a major increase in...

  13. Vegetation Sampling for Wetland Delineation: A Review and Synthesis of Methods and Sampling Issues

    Science.gov (United States)

    2010-07-01

    element in several forest inventory programs. These alternative metrics to cover or frequency are not regularly used in the majority of vegetation...as seedlings, saplings, and overstory vegetation are routinely collected in many forest inventory methods (Schreuder et al. 1993; McRoberts and...Service collects vegetation data using strata from long-term monitoring plots as part of its Forest Inventory and Analysis (FIA) and National Forest

  14. Tree range expansion in eastern North America fails to keep pace with climate warming at northern range limits.

    Science.gov (United States)

    Sittaro, Fabian; Paquette, Alain; Messier, Christian; Nock, Charles A

    2017-08-01

    Rising global temperatures are suggested to be drivers of shifts in tree species ranges. The resulting changes in community composition may negatively impact forest ecosystem function. However, long-term shifts in tree species ranges remain poorly documented. We test for shifts in the northern range limits of 16 temperate tree species in Quebec, Canada, using forest inventory data spanning three decades, 15° of longitude and 7° of latitude. Range shifts were correlated with climate warming and dispersal traits to understand potential mechanisms underlying changes. Shifts were calculated as the change in the 95th percentile of latitudinal occurrence between two inventory periods (1970-1978, 2000-2012) and for two life stages: saplings and adults. We also examined sapling and adult range offsets within each inventory, and changes in the offset through time. Tree species ranges shifted predominantly northward, although species responses varied. As expected shifts were greater for tree saplings, 0.34 km yr -1 , than for adults, 0.13 km yr -1 . Range limits were generally further north for adults compared to saplings, but the difference diminished through time, consistent with patterns observed for range shifts within each life stage. This suggests caution should be exercised when interpreting geographic range offsets between life stages as evidence of range shifts in the absence of temporal data. Species latitudinal velocities were on average <50% of the velocity required to equal the spatial velocity of climate change and were mostly unrelated to dispersal traits. Finally, our results add to the body of evidence suggesting tree species are mostly limited in their capacity to track climate warming, supporting concerns that warming will negatively impact the functioning of forest ecosystems. © 2017 John Wiley & Sons Ltd.

  15. Strip thinning young hardwood forests: multi-functional management for wood, wildlife, and bioenergy

    Science.gov (United States)

    Jamie Schuler; Ashlee Martin

    2016-01-01

    Upland hardwood forests dominate the Appalachian landscape. However, early successional forests are limited. In WV and PA, for example, only 8 percent of the timberland is classified as seedling and sapling-sized. Typically no management occurs in these forests due to the high cost of treatment and the lack of marketable products. If bioenergy markets come to fruition...

  16. Mangrove exploitation effects on biodiversity and ecosystem services

    DEFF Research Database (Denmark)

    Malik, Abdul; Fensholt, Rasmus; Mertz, Ole

    2015-01-01

    alba) belonging to six families (Avicenniaceae, Rhizophoraceae, Euphorbiaceae, Combretaceae, Arecaceae and Sonneratiaceae). Mangrove forests are now dominated by saplings and seedlings, with few trees above 15 cm diameter at breast height. Rhizophora sp. were found to be the most important and dominant...... harvesting on tree biodiversity in South Sulawesi, Indonesia. Using two line transects each in ten mangrove forests, mangrove composition, species dominance, density, frequency, coverage, and stem diameter and diversity were recorded. Interviews detailing provisioning ecosystem services were also conducted...

  17. Another perspective on altitudinal limits of alpine timberlines.

    Science.gov (United States)

    Smith, William K; Germino, Matthew J; Hancock, Thomas E; Johnson, Daniel M

    2003-11-01

    Recent hypotheses of timberline causation include the possibility that limitations to growth processes may be more limiting than restrictions on photosynthetic carbon gain, and that cold soil is a primary limiting factor at high altitude. However, almost all of the supporting data for timberline causation have come from studies on older trees, with little focus on the mechanisms of seedling establishment and the growth of saplings away from the forest edge into the treeline ecotone. We describe a conceptual model of timberline migration that invokes a strong dependence on ecological facilitation, beginning with seed germination and continuing through seedling establishment and sapling growth to the stage where trees with forest-like stature form new subalpine forest at a higher altitude. In addition to protection from severe mechanical damage, facilitation of photosynthetic carbon gain and carbon processing is enhanced by plasticity in plant form and microsite preference, enabling seedling survival and sapling growth inside and through the often severe boundary layer just above the ground cover. Several forms of facilitation (inanimate, interspecific, intraspecific and structural) result in substantial increases in photosynthetic carbon gain throughout the summer growth period, leading to enhanced root growth, subsequent amelioration of drought stress, and increased seedling survival. Avoidance of low temperatures and low-temperature photoinhibition of photosynthesis may be major benefits of the facilitation, enhancing photosynthetic carbon gain and respiratory-driven growth processes. We propose that the growth of vertical stems (flagged tree forms) from krummholz mats is analogous functionally to the facilitated growth of a seedling/sapling in and away from ground cover. Increasing abundance and growth of newly established trees in the treeline ecotone generates a structural and microsite facilitation characteristic of the subalpine forest below. This is followed

  18. Long-term responses of canopy-understorey interactions to disturbance severity in primary Picea abies forests

    Czech Academy of Sciences Publication Activity Database

    Bače, R.; Schurman, J.S.; Brabec, Marek; Čada, V.; Deprés, T.; Janda, P.; Lábusová, J.; Mikoláš, M.; Morrissey, R. C.; Mrhalová, H.; Nagel, T.A.; Nováková, M. H.; Seedre, M.; Synek, M.; Trotsiuk, V.; Svoboda, M.

    2017-01-01

    Roč. 28, č. 6 (2017), s. 1128-1139 ISSN 1100-9233 Grant - others:GA ČR(CZ) GA15-14840S Institutional support: RVO:67985807 Keywords : Disturbance regime * Natural regeneration * Primary forest * Picea abies (L.) Karst * Windstorms * Bark beetle * Understory light availability * Saplings and poles * Canopy openness * Mountain forest Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.924, year: 2016

  19. Characterization of Micronutrient Deficiency in Australian Red Cedar (Toona ciliata M. Roem var. australis)

    OpenAIRE

    Bruno da Silva Moretti; Antonio Eduardo Furtini Neto; Bruno Peres Benatti; Eduane José de Pádua; Lauana Lopes Santos; Julian Junio de Jesus Lacerda; Soami Fernanda Caio Deccetti

    2012-01-01

    The Australian Red Cedar presents a great exploitation potential in Brazil, but works about the nutrient requirements and deficiency characterization in that species are still scarce. The objectives of this work were evaluating the effects of the omission of micronutrients and characterizing the nutrient deficiency symptoms in Australian Red Cedar saplings. The experiment was conducted in a greenhouse for a 90-day period. Australian Red Cedar cuttings were cultivated in pots with a nutrient s...

  20. Studi Vegetasi dan Cadangan Karbon di Kawasan Hutan dengan Tujuan Khusus (KHDTK Senaru, Bayan Lombok Utara

    Directory of Open Access Journals (Sweden)

    Muhammad Husni Idris

    2013-01-01

    Full Text Available Study was conducted in Forest for Special Purpose (Education Forest ±225.7 ha in Senaru Village, North Lombok. The study was aimed to determine the potential of vegetation and carbon stocks. Land cover of study area was changed due to the timber management in 1993, planting mahogany and sengon in 1996, planting Aquilaria spin 1998-2001, and currently the implementation of agroforestry. Population for this study was the area of education forest intensively utilized by farmer (±120 ha. Sampling was determined by means of random with the intensity of 1% and distributed into 30 plots of 20x20m. Data analysis included analysis of vegetation, above ground carbon and soil carbon stock. The result shows that 32 species were found. There were 10, 8, 17 and 20 species of vegetation for seedlings, saplings, poles and trees, respectively. The first two highest Important Value Index (IVI for seedling and saplings were Coffea sp and Theobroma sp, where the IVI for seedling was 120.3 and 34.2, while for saplings were 146.1 and 92.5. Erytrhina sp and Pharaseriantes sp were the two highest IVI for poles and trees, where the IVI for poles was 77.9 and 48.7, while for trees was 87.1 and 79.9, respectively. Carbon stock of study area was 126.41 ton C/ha, which was differentiated into carbon stock for saplings (3.36 ton C/ha, pole (9.32 ton C/ha, trees (70.61 ton C/ha, understory (0.13 ton C/ha, litter (0.29 ton C/ha and soil (42.7 ton C/ha. The results of this study could be an input in develoving a model of Senaru educational forest as wells as future evaluation. Besides, it could enrich the existing information about forest resources.

  1. Brush reduces growth of thinned ponderosa pine in northern California

    Science.gov (United States)

    William W. Oliver

    1984-01-01

    The effects of tree spacing and brush competition were evaluated on a ponderosa pine (Pinus ponderosa Dougl. ex Laws. var. ponderosa) site of low productivity in California's North Coast Range. Eleven-year-old saplings were thinned to square spacings of 2.1, 2.4, 3.0, and 4.3 m (7, 8, 10, and 14 ft), and all, half, and none of...

  2. Life stage, not climate change, explains observed tree range shifts.

    Science.gov (United States)

    Máliš, František; Kopecký, Martin; Petřík, Petr; Vladovič, Jozef; Merganič, Ján; Vida, Tomáš

    2016-05-01

    Ongoing climate change is expected to shift tree species distribution and therefore affect forest biodiversity and ecosystem services. To assess and project tree distributional shifts, researchers may compare the distribution of juvenile and adult trees under the assumption that differences between tree life stages reflect distributional shifts triggered by climate change. However, the distribution of tree life stages could differ within the lifespan of trees, therefore, we hypothesize that currently observed distributional differences could represent shifts over ontogeny as opposed to climatically driven changes. Here, we test this hypothesis with data from 1435 plots resurveyed after more than three decades across the Western Carpathians. We compared seedling, sapling and adult distribution of 12 tree species along elevation, temperature and precipitation gradients. We analyzed (i) temporal shifts between the surveys and (ii) distributional differences between tree life stages within both surveys. Despite climate warming, tree species distribution of any life stage did not shift directionally upward along elevation between the surveys. Temporal elevational shifts were species specific and an order of magnitude lower than differences among tree life stages within the surveys. Our results show that the observed range shifts among tree life stages are more consistent with ontogenetic differences in the species' environmental requirements than with responses to recent climate change. The distribution of seedlings substantially differed from saplings and adults, while the distribution of saplings did not differ from adults, indicating a critical transition between seedling and sapling tree life stages. Future research has to take ontogenetic differences among life stages into account as we found that distributional differences recently observed worldwide may not reflect climate change but rather the different environmental requirements of tree life stages. © 2016

  3. Life-stage, not climate change, explains observed tree range shifts

    Science.gov (United States)

    Máliš, František; Kopecký, Martin; Petřík, Petr; Vladovič, Jozef; Merganič, Ján; Vida, Tomáš

    2017-01-01

    Ongoing climate change is expected to shift tree species distribution and therefore affect forest biodiversity and ecosystem services. To assess and project tree distributional shifts, researchers may compare the distribution of juvenile and adult trees under the assumption that differences between tree life-stages reflect distributional shifts triggered by climate change. However, the distribution of tree life-stages could differ within the lifespan of trees, therefore we hypothesize that currently observed distributional differences could represent shifts over ontogeny as opposed to climatically driven changes. Here we test this hypothesis with data from 1435 plots resurveyed after more than three decades across the Western Carpathians. We compared seedling, sapling and adult distribution of 12 tree species along elevation, temperature and precipitation gradients. We analyzed i) temporal shifts between the surveys and ii) distributional differences between tree life-stages within both surveys. Despite climate warming, tree species distribution of any life-stage did not shift directionally upward along elevation between the surveys. Temporal elevational shifts were species-specific and an order of magnitude lower than differences among tree life-stages within the surveys. Our results show that the observed range shifts among tree life-stages are more consistent with ontogenetic differences in the species’ environmental requirements than with responses to recent climate change. The distribution of seedlings substantially differed from saplings and adults, while the distribution of saplings did not differ from adults, indicating a critical transition between seedling and sapling tree life-stages. Future research has to take ontogenetic differences among life-stages into account as we found that distributional differences recently observed worldwide may not reflect climate change but rather the different environmental requirements of tree life-stages. PMID:26725258

  4. [Spatial point pattern analysis of Abies georgei var. smithii in forest of Sygera Mountains in southeast Tibet, China].

    Science.gov (United States)

    Xie, Chuan-qi; Tian, Min-xia; Zhao, Zhong-rui; Zheng, Wei-lie; Wang, Guo-yan

    2015-06-01

    In this study, based on a 4 hm2 stem-mapping plot, we analyzed spatial distributions of Abies georgei var. smithii, the dominant species in forest of Sygera Mountains in southeast Tibet, China. Pair-correlation function was used to characterize univariate spatial point patterns of three size classes of the population and bivariate spatial patterns between those and different sizes of dead wood. A. georgei var. smithii population was characterized by reverse J-shaped DBH distribution, indicating an increasing population. Saplings of the population were spatially obviously aggregated at the small scales (0-7 m), and mid-sized trees and large-sized trees of the population were randomly or uniformly distributed. The aggregation intensities of A. georgei var. smithii decreased with the increasing diameter classes and spatial scales. Saplings and mid-sized trees were significantly and negatively associated with large-sized trees at the small scales (0-35 and 0-30 m), but the associations reversed at the large scales (45-100 and 80-100 m). In addition, with the increasing age difference between diameter classes of the population, the intensities of positive or negative correlations increased. Spatial associations between saplings and dead large-sized trees, and between mid-sized trees and dead large-sized trees were negative at the small scales (0-34 and 5-27 m), but positive at the large scales (49-100 and 73-100 m). This suggested that released niche space due to dead large-sized trees is not enough to weaken their negative impacts on saplings. We concluded that self-thinning effect and Janzen-Connell hypothesis may be the main mechanisms for the spatial pattern formation of A. georgei var. smithii population.

  5. Divergent scaling of respiration rates to nitrogen and phosphorus across four woody seedlings between different growing seasons

    OpenAIRE

    Fan, Ruirui; Sun, Jun; Yang, Fuchun; Li, Man; Zheng, Yuan; Zhong, Quanlin; Cheng, Dongliang

    2017-01-01

    Abstract Empirical studies indicate that the exponents governing the scaling of plant respiration rates (R) with respect to biomass (M) numerically vary between three‐fourth for adult plants and 1.0 for seedlings and saplings and are affected by nitrogen (N) and phosphorus (P) content. However, whether the scaling of R with respect to M (or N and P) varies among different phylogenetic groups (e.g., gymnosperms vs. angiosperms) or during the growing and dormant seasons remains unclear. We meas...

  6. Abundance and Size Distribution of Cavity Trees in Second-Growth and Old-Growth Central Hardwood Forests

    Science.gov (United States)

    Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson III; David R. Larsen

    2005-01-01

    In central hardwood forests, mean cavity-tree abundance increases with increasing standsize class (seedling/sapling, pole, sawtimber, old-growth). However, within a size class, the number of cavity trees is highly variable among 0.1-ha inventory plots. Plots in young stands are most likely to have no cavity trees, but some plots may have more than 50 cavity trees/ha....

  7. Populasi Dan Kesesuaian Habitat Langkap (Arenga Obtusifolia Mart.) Di Cagar Alam Leuweung Sancang, Jawa Barat

    OpenAIRE

    Usmadi, Didi; Hikmat, Agus; Witono, Joko Ridho; Prasetyo, Lilik Budi

    2015-01-01

    The growth and regeneration of langkap in natural habitat is very fast and has invasive tendencies. The aim of study was to analyze the population and population structure of langkap in Leuweung Sancang Nature Reserve, and build spatial models of habitat suitability langkap in Leuweung Sancang Nature Reserve. Data were collected using a sampling method with a number of plots along the transect line. Langkap has become the dominant species in Leuweung Sancang Nature Reserve on saplings and pol...

  8. Landfill Remediation Feasibility Study, Devens, Massachusetts. Volume 2. Appendices A Through F

    Science.gov (United States)

    1997-01-01

    well as some transitional upland species. Within the wooded overstory, red maple (Acer rubrum) and swamp white oak ( Quercus bicolor) are present. The...sparse shrub layer consists of several saplings of the tree species listed above, as well as steeplebush (Spirea tomentosa), red oak ( Quercus rubra), and...polygamum), sedges (Carex spp., Carex lurida), speckled alder (Alnus rugosa ), reed canary grass (Phalaris arundinacea), northern arrowwood, marsh St

  9. The influence of micropropagation on growth and coppicing ability of Eucalyptus polybractea.

    Science.gov (United States)

    Goodger, Jason Q D; Woodrow, Ian E

    2010-02-01

    A micropropagation protocol was recently developed for Eucalyptus polybractea R.T. Baker, a commercially important eucalypt grown in short-rotation coppice cultivation and harvested for its foliar 1,8-cineole oil. Micropropagation of elite E. polybractea trees has resulted in selection gains for foliar oil traits, but decreased above-ground biomass accumulation has been observed in clones compared to related half-sibling families. This study aims to use a greenhouse study to investigate if micropropagation induces somaclonal variation that can account for the reduction in above-ground biomass in E. polybractea clones. Secondly, the study aims to compare the coppicing ability of micropropagated clones with related half-sibling seedlings using de-topped plantation-grown saplings. The results of the greenhouse study suggest that micropropagation of E. polybractea induces somaclonal variation that manifests in more mature leaf morphologies such as increased foliar oil concentrations and lower specific leaf area (SLA), attributable to an isobilateral arrangement of increased palisade mesophyll layers. Lower SLA, rather than differences in root allocation, is likely to be a key contributor to the lower relative growth rates observed in early sapling growth of micropropagated clones. In the field study, all micropropagated and seedling-derived E. polybractea saplings coppiced vigorously in the 12 months after de-topping. The coppice growth was so vigorous in the 12 months after de-topping that total above-ground biomass equalled that of the 27-month-old saplings, irrespective of propagation source. The morphological distinction between leaves of micropropagated and seed-derived plants was no longer evident in the coppice regrowth. The results presented here suggest that the micropropagated leaf morphology and the resultant growth reduction is transient and micropropagated plants coppice just as vigorously as seed-derived plants. Therefore, micropropagation is unlikely to

  10. Riparian Vegetation, Natural Succession, and the Challenge of Maintaining Bare Sandbar Nesting Habitat for Least Terns and Piping Plovers

    Science.gov (United States)

    2012-12-01

    White Vervain, Switch Grass, Goose Grass, Elongate Bladder Pod , Winged Pigweed Mixed Herb Perennial herbs and grasses in mesic to xeric conditions on...LOWVEG line. Species: Bagpod, Sandspur, Partridge Pea , Cockle-bur, Hogwort, Indian-hemp, Common Crabgrass, Winged Pigweed, Mist Flower, Gumweed Mixed...Crabgrass, Winged Pigweed, Hogwort, Cottonwood, Partridge Pea Willow Thicket Saplings in frequently-flooded to mesic conditions on slopes, low flood

  11. Seed-deposition and recruitment patterns of Clusia species in a disturbed tropical montane forest in Bolivia

    Science.gov (United States)

    Saavedra, Francisco; Hensen, Isabell; Apaza Quevedo, Amira; Neuschulz, Eike Lena; Schleuning, Matthias

    2017-11-01

    Spatial patterns of seed dispersal and recruitment of fleshy-fruited plants in tropical forests are supposed to be driven by the activity of animal seed dispersers, but the spatial patterns of seed dispersal, seedlings and saplings have rarely been analyzed simultaneously. We studied seed deposition and recruitment patterns of three Clusia species in a tropical montane forest of the Bolivian Andes and tested whether these patterns changed between habitat types (forest edge vs. forest interior), distance to the fruiting tree and consecutive recruitment stages of the seedlings. We recorded the number of seeds deposited in seed traps to assess the local seed-deposition pattern and the abundance and distribution of seedlings and saplings to evaluate the spatial pattern of recruitment. More seeds were removed and deposited at the forest edge than in the interior. The number of deposited seeds decreased with distance from the fruiting tree and was spatially clustered in both habitat types. The density of 1-yr-old seedlings and saplings was higher at forest edges, whereas the density of 2-yr-old seedlings was similar in both habitat types. While seedlings were almost randomly distributed, seeds and saplings were spatially clustered in both habitat types. Our findings demonstrate systematic changes in spatial patterns of recruits across the plant regeneration cycle and suggest that the differential effects of biotic and abiotic factors determine plant recruitment at the edges and in the interior of tropical montane forests. These differences in the spatial distribution of individuals across recruitment stages may have strong effects on plant community dynamics and influence plant species coexistence in disturbed tropical forests.

  12. Physiological responses of birch (Betula pendula) to ozone: a comparison between open-soil-grown trees exposed for six growing seasons and potted seedlings exposed for one season

    Energy Technology Data Exchange (ETDEWEB)

    Oksanen, E. [Kuopio Univ., Dept. of Ecology and Environmental Science, Kuopio (Finland)

    2003-06-01

    Physiological responses to ozone exposure over one growing season of four year-old potted ozone-tolerant white birch saplings were compared with saplings of six year-old open-soil-grown trees of the same birch variety that has been previously fumigated with ozone for five growing season. Both plant groups were exposed to ambient and elevated ozone concentrations under similar microclimatic conditions in a free air ozone exposure facility. Growth in foliage, net photosynthesis, stomatal conductance, starch and nutrient concentrations and differences in ozone responses between lower, middle and upper sections of the canopy were determined. Potted saplings showed no effect to elevated ozone concentration, while the open-soil-grown trees showed a 3 to 38 per cent reduction in shoot growth, a 22 per cent reduction in the number of overwintering buds, a 26-65 per cent decrease in net annual photosynthesis, 30 per cent reduction in starch, and a 20-23 per cent reduction in nitrogen concentration, as well as disturbances in stomatal conductance. Various explanations are offered for the higher ozone sensitivity of open-soil-grown trees, among them cumulative carry-over effects of multi-year exposure resulting in impaired bud formation, reduced capacity for photosynthetic compensation for ozone damage, and slower leaf senescence. The main conclusion was that in European white birch exposure period and plant size were the most important factors affecting ozone tolerance. 46 refs., 2 tabs., 6 figs.

  13. Light environment alters ozone uptake per net photosynthetic rate in black cherry trees.

    Science.gov (United States)

    Fredericksen, T S; Kolb, T E; Skelly, J M; Steiner, K C; Joyce, B J; Savage, J E

    1996-05-01

    Foliar ozone uptake rates of different-sized black cherry (Prunus serotina Ehrh.) trees were compared within a deciduous forest and adjacent openings in north-central Pennsylvania during one growing season. Study trees included open-grown seedlings and saplings, forest understory seedlings and saplings, and sunlit and shaded portions of mature canopy tree crowns. Instantaneous ozone uptake rates were highest in high-light environments primarily because of higher stomatal conductances. Low ozone uptake rates of seedlings and saplings in the forest understory could be attributed partially to lower average ambient ozone concentrations compared to the canopy and open environments. Among the tree size and light combinations tested, ozone uptake rates were highest in open-grown seedlings and lowest in forest-grown seedlings. Despite lower ozone uptake rates of foliage in shaded environments, ozone uptake per net photosynthesis of foliage in shaded environments was significantly higher than that of foliage in sunlit environments because of weaker coupling between net photosynthesis and stomatal conductance in shaded environments. The potential for greater ozone injury in shaded environments as a result of greater ozone uptake per net photosynthesis is consistent with previous reports of greater ozone injury in shaded foliage than in sunlit foliage.

  14. Habitat Fragmentation Drives Plant Community Assembly Processes across Life Stages.

    Directory of Open Access Journals (Sweden)

    Guang Hu

    Full Text Available Habitat fragmentation is one of the principal causes of biodiversity loss and hence understanding its impacts on community assembly and disassembly is an important topic in ecology. We studied the relationships between fragmentation and community assembly processes in the land-bridge island system of Thousand Island Lake in East China. We focused on the changes in species diversity and phylogenetic diversity that occurred between life stages of woody plants growing on these islands. The observed diversities were compared with the expected diversities from random null models to characterize assembly processes. Regression tree analysis was used to illustrate the relationships between island attributes and community assembly processes. We found that different assembly processes predominate in the seedlings-to-saplings life-stage transition (SS vs. the saplings-to-trees transition (ST. Island area was the main attribute driving the assembly process in SS. In ST, island isolation was more important. Within a fragmented landscape, the factors driving community assembly processes were found to differ between life stage transitions. Environmental filtering had a strong effect on the seedlings-to-saplings life-stage transition. Habitat isolation and dispersal limitation influenced all plant life stages, but had a weaker effect on communities than area. These findings add to our understanding of the processes driving community assembly and species coexistence in the context of pervasive and widespread habitat loss and fragmentation.

  15. Host plant use among closely related Anaea butterfly species (Lepidoptera, Nymphalidae, Charaxinae

    Directory of Open Access Journals (Sweden)

    QUEIROZ J. M.

    2002-01-01

    Full Text Available There is a great number of Charaxinae (Lepidoptera: Nymphalidae species in the tropics whose larvae feed on several plant families. However the genus Anaea is almost always associated with Croton species (Euphorbiaceae. This work describes patterns of host plant use by immature and adult abundance on different vertical strata of sympatric Anaea species in a forest of Southeastern Brazil. Quantitative samples of leaves were taken in April/1999 and May/2000 to collect eggs and larvae of four Anaea species on C.alchorneicarpus, C. floribundus and C. salutaris in a semideciduous forest. Sampled leaves were divided into three classes of plant phenological stage: saplings, shrubs and trees. The results showed that the butterfly species are segregating in host plant use on two scales: host plant species and plant phenological stages. C. alchorneicarpus was used by only one Anaea species, whereas C. floribundus was used by three species and C. salutaris by four Anaea species. There was one Anaea species concentrated on sapling, another on sapling/shrub and two others on shrub/tree leaves. Adults of Anaea were more frequent at canopy traps but there were no differences among species caught in traps at different vertical positions. This work supplements early studies on host plant use among Charaxinae species and it describes how a guild of closely related butterfly species may be organized in a complex tropical habitat.

  16. The impact of textile wastewater irrigation on the growth and development of apple plant.

    Science.gov (United States)

    Zengınbal, Hamdi; Okcu, Gamze Dogdu; Yalcuk, Arda

    2018-01-28

    In this work, the effect of irrigation with textile wastewaters on the growth and development of "Golden Delicious" apple sapling was examined over a one-year period. Municipal water prepared as a control sample (T 0 ), 1/3 diluted (T 1 ), and undiluted (T 2 ) raw textile wastewater was used as the three different irrigation water samples. Two replications of each test were performed on three random samples each time. When examining the effects of T 0 , T 1 , and T 2 irrigation water on plant growth, it was found that T 1 irrigation water significantly increased the weight, the shoot length, and the diameter of the sapling. Despite increasing Ni and Cr metals in the apple saplings' leaves when irrigated with T 2 water, plant growth was restricted due to the lack of basic nutrients. When taking certain aspects into account, such as the proper treatment of wastewater, then 1/3 diluted textile wastewater can be used as agricultural irrigation water for the apple plants.

  17. Thermal acclimation of leaf respiration but not photosynthesis in Populus deltoides x nigra.

    Science.gov (United States)

    Ow, Lai Fern; Griffin, Kevin L; Whitehead, David; Walcroft, Adrian S; Turnbull, Matthew H

    2008-01-01

    Dark respiration and photosynthesis were measured in leaves of poplar Populus deltoides x nigra ('Veronese') saplings to investigate the extent of respiratory and photosynthetic acclimation in pre-existing and newly emerged leaves to abrupt changes in air temperature. The saplings were grown at three temperature regimes and at high and low nitrogen availabilities. Rates of photosynthesis and dark respiration (R(d)) were measured at the initial temperature and the saplings were then transferred to a different temperature regime, where the plants remained for a second and third round of measurements on pre-existing and newly emerged leaves. Acclimation of photosynthesis was limited following transfer to warmer or cooler growing conditions. There was strong evidence of cold and warm acclimation of R(d) to growth temperature, but this was limited in pre-existing leaves. Full acclimation of R(d )was restricted to newly emerged leaves grown at the new growth temperature. These findings indicate that the extent of thermal acclimation differs significantly between photosynthesis and respiration. Importantly, pre-existing leaves in poplar were capable of some respiratory acclimation, but full acclimation was observed only in newly emerged leaves. The R(d)/A(max) ratio declined at higher growth temperatures, and nitrogen status of leaves had little impact on the degree of acclimation.

  18. Early post-fire regeneration of a Pinus halepensis forest on Mount Parnis, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Thanos, C.A.; Daskalakou, E.N.; Nikolaidou, S. [Athens Univ. (Greece). Dept. of Botany

    1996-05-01

    The post-fire regeneration of a 45-yr-old Pinus halepensis (Aleppo pine) forest, burned in July 1989, has been studied on Mount Parnis, Attiki, Greece. Four experimental plots at various slopes and exposures were established at altitudes of 400 - 450 m, and monitored for 3 yr at 3-month intervals. Early regeneration took place abundantly, through both resprouting and seed germination of mostly hard-seeded herbs and shrubs; the floristic richness was high with 80 taxa. Pine seedling emergence took place during the winter of the first post-fire year. The mean pine seedling density by the end of the recruitment period (March 1990) was 5-6 seedlings/m{sup 2}. This density decreased slightly during late spring and considerably during summer. During the second post-fire year only a relatively slight decline was observed; thereafter the density was stabilized to 1-2 seedlings/m{sup 2}. Mortality follows a negative exponential curve that levels off at ca. 20%. Height distributions throughout the three post-fire years were all positively skewed as a result of the presence of few very tall saplings. A considerable fraction (20%) of very short (5-15 cm) saplings were still alive 39 months after the fire; these may constitute the sapling bank. Based on the analysis of height distribution curves, it is concluded that the taller seedlings survived significantly better than the shorter ones. 36 refs, 3 figs, 5 tabs

  19. Modeling the Influence of Forest Structure on Microsite Habitat Use by Snowshoe Hares

    Directory of Open Access Journals (Sweden)

    Angela K. Fuller

    2013-01-01

    Full Text Available Snowshoe hare (Lepus americanus is an important prey species for many Carnivora and has strong influences on community structure and function in northern forests. An understanding of within-stand (microsite forest structural characteristics that promote high use by hares is important to provide forest management guidelines. We measured forest structural characteristics at the microsite-scale in north-central Maine and used an information-theoretic modeling approach to infer which characteristics were most strongly associated with use by hares during winter. We measured overwinter hare pellet density to model relationships among microsite-scale vegetation structure and hare use. Overwinter pellet density was positively associated with live stem cover (3 × coniferous saplings + deciduous saplings and negatively associated with overstory canopy closure; the two variables explained 71% of the variation in microsite use by hares. The highest pellet densities were in grids with canopy closure 22,000 stems/ha. Silvicultural practices that create dense areas of conifer and deciduous saplings should receive high within-stand use by hares in winter. These conditions can be achieved by promoting the release of advanced regeneration and reducing overstory cover to encourage establishment of shade-intolerant species; clearcutting is one such silvicultural prescription to achieve these conditions.

  20. Habitat Fragmentation Drives Plant Community Assembly Processes across Life Stages.

    Science.gov (United States)

    Hu, Guang; Feeley, Kenneth J; Yu, Mingjian

    2016-01-01

    Habitat fragmentation is one of the principal causes of biodiversity loss and hence understanding its impacts on community assembly and disassembly is an important topic in ecology. We studied the relationships between fragmentation and community assembly processes in the land-bridge island system of Thousand Island Lake in East China. We focused on the changes in species diversity and phylogenetic diversity that occurred between life stages of woody plants growing on these islands. The observed diversities were compared with the expected diversities from random null models to characterize assembly processes. Regression tree analysis was used to illustrate the relationships between island attributes and community assembly processes. We found that different assembly processes predominate in the seedlings-to-saplings life-stage transition (SS) vs. the saplings-to-trees transition (ST). Island area was the main attribute driving the assembly process in SS. In ST, island isolation was more important. Within a fragmented landscape, the factors driving community assembly processes were found to differ between life stage transitions. Environmental filtering had a strong effect on the seedlings-to-saplings life-stage transition. Habitat isolation and dispersal limitation influenced all plant life stages, but had a weaker effect on communities than area. These findings add to our understanding of the processes driving community assembly and species coexistence in the context of pervasive and widespread habitat loss and fragmentation.

  1. Growth reduction after defoliation is independent of CO2 supply in deciduous and evergreen young oaks.

    Science.gov (United States)

    Schmid, Sandra; Palacio, Sara; Hoch, Günter

    2017-06-01

    Reduced productivity of trees after defoliation might be caused by limited carbon (C) availability. We investigated the combined effect of different atmospheric CO2 concentrations (160, 280 and 560 ppm) and early season defoliation on the growth and C reserves (nonstructural carbohydrates (NSC)) of saplings of two oak species with different leaf habits (deciduous Quercus petraea and evergreen Quercus ilex). In both species, higher CO2 supply significantly enhanced growth. Defoliation had a strong negative impact on growth (stronger for Q. ilex), but the relative reduction of growth caused by defoliation within each CO2 treatment was very similar across all three CO2 concentrations. Low CO2 and defoliation led to decreased NSC tissue concentrations mainly in the middle of the growing season in Q. ilex, but not in Q. petraea. However, also in Q. ilex, NSC increased in woody tissues in defoliated and low-CO2 saplings towards the end of the growing season. Although the saplings were C limited under these specific experimental conditions, growth reduction after defoliation was not directly caused by C limitation. Rather, growth of trees followed a strong allometric relationship between total leaf area and conductive woody tissue, which did not change across species, CO2 concentrations and defoliation treatments. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  2. Acid mist and soil Ca and Al alter the mineral nutrition and physiology of red spruce

    Energy Technology Data Exchange (ETDEWEB)

    Schaberg, P. G.; Murakami, P. F. [Northeastern Research Station, Burlington, VT (United States); Dehayes, D. H.; Hawley, G. J.; Strimbeck, G. R.; Borer, C. H. [Vermont Univ., School of Natural Resources, Burlington, VT (United States); Cumming, J. R. [West Virginia Univ, Dept. of Biology, Morgantown, WV (United States)

    2000-01-01

    The effects and potential interactions of acid mist and soil solutions of calcium and aluminium treatments on foliar cation concentrations, membrane-associated calcium leaching, growth, carbon exchange and cold tolerance in red spruce saplings was investigated. Results showed that soil solution calcium addition increased foliar calcium and zinc concentrations and increased the rate of respiration early in the growing season. Soil aluminium treatment reduced foliar concentrations of calcium, manganese, magnesium, phosphorus and zinc, which in turn, produced smaller stem diameters and shoot lengths. On the whole, aluminium -induced alterations in growth or physiology appeared to be independent of foliar calcium status. As a general rule, reduction in cation concentration associated with aluminium addition were greater for pH 5.0-treated saplings than for pH 3.0-treated saplings. This observation led the investigators to conclude that the mechanism underlying acid-induced reductions in foliar cold tolerance in red spruce is hydrogen ion-induced leaching of membrane-associated calcium from mesophyll cells. 93 refs., 6 tabs., 1 fig.

  3. The Effect of Paclobutrazol on Morphological, Physiological and Gas Exchange Charactersitics of Pear (Pyrus communus cv. Shah Mive under Different Irrigation Regimes

    Directory of Open Access Journals (Sweden)

    Taimoor Javadi

    2017-02-01

    Full Text Available Introduction: Drought is a major environmental stress that affects agricultural systems and induces several physiological, biochemical and molecular responses in plants. Drought inhibits the plant photosynthesis causing changes of chlorophyll contents, damage the photosynthetic apparatus and decreases plant growth and development. Generally, the environmental stresses, especially drought stress, give rise to accumulation of soluble carbohydrates, proline and free amino acids as well as antioxidant compounds. Triazoles are the active ingredient of fungicides (propoconazole, penconazole, epixiconazole and some growth regulators. The fungicidal properties of triazoles depend on inhibition of the C4-demethylase reactions in sterol biosynthesis of fungi. However, triazole-based fungicides induce a suite of morphological and physiological adaptations and allow plants to tolerate a broad range of environmental stresses including drought, herbicide treatment and elevated temperatures. The growth inhibitor paclobutrazol (PBZ is a triazole and has been reported to protect plants against several environmental stresses, i.e. drought, low and high temperature. The purpose of this study was to evaluate the effect of palobutrazol on vegetative, physiological and gas exchange characteristics of pear (Pyrus communis cv. ShahMive under different irrigation regimes. Materials and Methods: In March, 2011, 1-year-old pear (Pyrus communis cv. ShahMive saplings 80±2 cm high were planted in 20-l plastic pots filled with loamy sand soil (8% clay, 15% silt, 77% Sand in experimental greenhouse. Paclobutrazol was added to soil at the same time with sapling cultivation at rates of 0, 0.15 and 0.3 g active ingredient per pot. PBZ was diluted in 500 ml distilled water and solution applied to the soil at the base of the saplings on pots. The control saplings were treated with distilled water of equal volume. Vegetative (stem growth, stem diameter, leaf number, shoot dry

  4. Direct and indirect landscape effects on Quercus ilex regeneration in heterogeneous environments.

    Science.gov (United States)

    Puerta-Piñero, Carolina; Pino, Joan; Gómez, José María

    2012-12-01

    Understanding how plant-animal interactions shape plant regeneration is traditionally examined at local scales. In contrast, landscape ecologists working at regional scales often have to infer the mechanisms underlying vegetation patterns. In this study, we empirically explored how landscape attributes (patch connectivity, size, shape, irradiance, slope, and elevation) influence biotic interactions in 1- and 2-year seedlings and saplings of Quercus ilex. We combined field data and GIS-based information under a set of five connectivity scenarios, presuming low, intermediate, and long-distance seed dispersal. Our study emphasizes that landscape, apart from its direct effects on plants, plays a key, albeit indirect, role in plant demography through its effects on seed dispersers and predators. Moreover, the effects of landscape on recruitment differed between plant life stages. One-year seedlings and saplings appear to depend more on plant-animal interactions, while 2-year seedlings depend more on irradiance. Differences in patch connectivity resulted in direct and indirect effects on biotic interactions, which, in turn, produced contrasting positive and negative effects on regeneration at different stages of the life cycle. While jays and wild boars seem crucial to all life stages and most of the connectivity scenarios, rodents and herbivores affected only 1-year seedlings and saplings, respectively, and only a few of the connectivity scenarios. By simultaneously including an ensemble of explanatory factors, our study emphasizes that regeneration depends on a set of key drivers, both abiotic (i.e. irradiance) and biotic (i.e. jays and wild boars), whose effects are greatly modulated by landscape traits.

  5. Insights into some physiological and biochemical responses of Populus alba and Populus nigra to lead contamination

    Directory of Open Access Journals (Sweden)

    Elham Etemadi

    2016-12-01

    Full Text Available The effects of lead (PbCl2 increment, under hydroponic conditions up to 15, 45 and 90 mg/l in presence of EDTA, on some physiological and biochemical traits of one year old saplings of P. nigra and P. alba, were investigated. Six weeks after establishing in target concentration, the amount of lead, biomass, water, soluble sugars, proline, electrolyte leakage, malondialdehyde, and pigments were assessed in different organs. The results revealed that with increasing lead concentration in culture medium in the studied period, the amount of lead in saplings increased, but no effect was observed on their biomass. In both species the magnitude of lead accumulation in root was higher than leaf. P. nigra had more water and less soluble sugars than P. alba. The concentration of soluble sugars increased up to 1.5 times with lead increment in both species, but proline content increased only in P. nigra up to 2 times and remained constant in P. alba. Elevation of electrolyte leakage in saplings of P. nigra in excess lead treatment was accompanied by no change in malondialdehyde content. Concentrations of pigments were not affected by lead, and only the ratio of chlorophyll a to b in P. nigra increased in high lead concentration. In general both species accumulated high extent of lead in their organs. But it seems that P. nigra, at least with respect of enhancing plasma membrane permeability, increasing proline and the ratio of chlorophyll a to b, was more sensitive to this toxic metal in compare with P. alba.

  6. Suitability of Taxodium distichum for Afforesting the Littoral Zone of the Three Gorges Reservoir.

    Science.gov (United States)

    Li, Bo; Du, Chunlan; Yuan, Xingzhong; Willison, J H Martin; Xiao, Hongyan

    2016-01-01

    The littoral zone ecosystem of the Three Gorges Reservoir (TGR) has become significantly degraded by annual cycles of prolonged winter flooding and summer drought. For purposes of flood control and sediment management, the water level in the reservoir is lowered by 30 m during the summer monsoon season and raised again to 175 m above sea level each year at the end of the monsoon period. To explore an effective way to promote biodiversity and associated ecosystem services, we examined Taxodium distichum as a species for afforesting the littoral zone. Sapling growth variations were measured after two rounds of winter flooding. Dominant influence factors were determined by redundancy analysis. Herb community similarities between the experimental afforested areas and nearby control areas were assessed to detect the ecosystem influence of the experimental afforestation. 94.5% of saplings planted at elevations above 168 m survived. All measured growth indices (tree height, diameter at breast height, crown width and foliage density) decreased as the flood depth increased. Completely submerged saplings had a mean dieback height of -0.65 m. Greater initial foliage density led to increased tree height and stem diameter. Shannon-Wiener indices were not significantly different between plots in experimental and control areas, but the low similarity of herb communities between experimental and control areas (0.242 on average) suggested that afforestation would enrich plant community structure and improve littoral zone ecosystem stability. Because littoral zone afforestation provides several ecosystem services (habitat, carbon sink, water purification and landscaping), it is a promising revegetation model for the TGR.

  7. Suitability of Taxodium distichum for Afforesting the Littoral Zone of the Three Gorges Reservoir.

    Directory of Open Access Journals (Sweden)

    Bo Li

    Full Text Available The littoral zone ecosystem of the Three Gorges Reservoir (TGR has become significantly degraded by annual cycles of prolonged winter flooding and summer drought. For purposes of flood control and sediment management, the water level in the reservoir is lowered by 30 m during the summer monsoon season and raised again to 175 m above sea level each year at the end of the monsoon period. To explore an effective way to promote biodiversity and associated ecosystem services, we examined Taxodium distichum as a species for afforesting the littoral zone. Sapling growth variations were measured after two rounds of winter flooding. Dominant influence factors were determined by redundancy analysis. Herb community similarities between the experimental afforested areas and nearby control areas were assessed to detect the ecosystem influence of the experimental afforestation. 94.5% of saplings planted at elevations above 168 m survived. All measured growth indices (tree height, diameter at breast height, crown width and foliage density decreased as the flood depth increased. Completely submerged saplings had a mean dieback height of -0.65 m. Greater initial foliage density led to increased tree height and stem diameter. Shannon-Wiener indices were not significantly different between plots in experimental and control areas, but the low similarity of herb communities between experimental and control areas (0.242 on average suggested that afforestation would enrich plant community structure and improve littoral zone ecosystem stability. Because littoral zone afforestation provides several ecosystem services (habitat, carbon sink, water purification and landscaping, it is a promising revegetation model for the TGR.

  8. Assessment and implications of intraspecific and phenological variability in monoterpenes of Scots pine (Pinus sylvestris) foliage.

    Science.gov (United States)

    Thoss, Vera; O'Reilly-Wapstra, Julianne; Iason, Glenn R

    2007-03-01

    Scots pine populations contain individuals with widely differing amounts and composition of monoterpenes and exist as one of two chemotypes: with or without delta3-carene. We investigated the significance for ecological studies of two types of variation in monoterpenes: (1) the inherent variability in the concentration of monoterpenes or their relative amounts in needles of seedlings, saplings, and mature trees; and (2) phenological variation in developing needles. The relative composition of needle monoterpenes in 5-year-old saplings changed during the needle development period until the final composition was reached upon needle maturity. Changes in composition depended on chemotype. Needles of the "no-delta3-carene" chemotype had higher absolute concentrations of alpha-pinene, beta-pinene, camphene, and total monoterpenes than "delta3-carene" chemotype. For the "delta3-carene" chemotype, the relative concentration of delta3-carene during the needle growing season and immediately after emergence of seedlings was higher compared to that reached at needle maturity. Repeated removal of single needles (at weekly intervals during growth) from 5-year-old saplings did not influence the composition of monoterpenes. Within a natural Scots pine dominated woodland, 18% of mature Scots pines (N=574) belonged to the "no-delta3-carene" chemotype. Chemotypic variation within populations means that the statistical power with which differences in monoterpene concentrations can be detected is lower when sampling from the whole population compared to sampling within chemotypes. Reduction of this background variation and accounting for chiral variation if present, would significantly aid efficiency, interpretation, and understanding of processes in chemical and ecological research. One method for achieving this is the screening of plants for chemotypes before the establishment of experiments or field sampling regimes. We present a summary of suitable analytical methods for needle

  9. 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.

  10. The guava tree as bioindicator during the process of fuel replacement of an oil refinery.

    Science.gov (United States)

    Silva, Simone F; Meirelles, Sérgio T; Moraes, Regina M

    2013-05-01

    This study was performed to verify whether the exchange of the fuel used in the boilers of a crude oil refinery located in Cubatão (SE Brazil) would result in alterations on gas exchange, growth and leaf injuries in saplings of Psidium guajava 'Paluma'. The purpose of the refinery was to reduce the SO2 emission, but using natural gas as fuel could increase the concentrations of O3 precursors in the atmosphere. Thus a biomonitoring was performed with a native species sensitive to O3. The plants were exposed in five areas (CM1, CM5, CEPEMA, Centro, and RP) at different distances to the refinery, both before and after the fuel exchange. We performed six exposures under environmental conditions, with length of ca. 90 days each. With the utilization of natural gas, the saplings presented reductions in carbon assimilation rate under saturating light conditions (Asat, μmolCO2m(-2)s(-1)) and the stomatal conductance (gs, molH2Om(-2)s(-1)), and increase in height, number of leaves, and dry mass of leaves and shoots. There were also reductions in root dry mass and in the root/shoot ratio. The saplings also presented O3-induced leaf injuries. The responses of P. guajava 'Paluma' were altered after the fuel exchange as a result of a new combination of pollutants in the atmosphere. The fuel exchange has not resulted in environmental benefit to the surrounding forest; it has only altered the contamination profile of the region. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Resource Potential Analysis Of Honey Bee Feed Apis Dorsata In Mountain Tinanggo Kolaka

    Directory of Open Access Journals (Sweden)

    Rosmarlinasiah

    2015-04-01

    Full Text Available Abstract Honey Bees feed in the form of nectar pollen and water the bees used to build nests and establish colonies. A hexagonal honeycomb as a store of honey pollen and seedlings. If feed honey bees flower plants are abundantly available continuously then the always active bees build nests and fill each cell nest of honey pollen eggs and other products. The purpose of research is to determine the types of flowering plants as a potential feed honey bees nectar and pollen. The experiment was conducted at Mount Tinanggo Kolaka Southeast Sulawesi Province which lasted from March 2013 until March 2014. Determined by purposive sample observations based on the location of the nearest and farthest honey using the method of terraced paths. Samples were placed systematically with the withdrawal of the central point on the tree path beehive a radius of 700 meters from the center of the North East South and West. Data type of plant plant density and stem diameter were analyzed to determine the importance value index and diversity index type at the tree level trees saplings and seedlings. Based on the results of the enumeration on the collected research sites by 591 plant specimens were clustered on the tree level 152 level 102 poles 178 degree and 159 degree stake seedlings. Levels of tree species diversity and relatively abundant mast high and the level of saplings and seedlings are relatively abundant. The dominant species on the tree level Meranti Shorea sp and rambutan Nephelium lappaceum levels Holea pole Cleistantus laevis Hook f and Kuma Palaquium obovatum Engl the level of saplings and seedlings levels Holea Cleistantus laevis Hook f and rambutan Nephelium lappaceum. There are 237 types of flowering plants averaging 19.75 per month flowering plants and flowering peak was in September.

  12. Analisis Vegetasi Sebagai Dasar Pengembangan Agroforestri di DAS Mikro Desa Tukad Sumaga, Kecamatan Gerokgak, Kabupaten Buleleng

    Directory of Open Access Journals (Sweden)

    I WAYAN GEDE WIRYANTARA

    2015-06-01

    Full Text Available Vegetations Analysis As A Basic ForAgroforestry Development In Micro Watershed TukadSumaga Village, Gerokgak District, Buleleng Regency.Forest changed to agricultural hasconsciousness can effected many problems such as soil degradations, erosion, flora and fauna extinctions,floods, dryness, and even global environmental change. Agroforestry is one of solutions to protect thebiodiversity. The research was held at Micro Watershed Tukad Sumaga Village, Gerokgak District,Buleleng Regency which consist of intercropping agroforestry system, alley cropping agroforestry system,and the trees for soil conservations agroforestry system. The purpose of this research is to discoverbiodiversity and composition of vegetations species in each agroforestry system and also to find out theagroforestry management level at Micro Watershed Tukad Sumaga Village. The research result showsthat the biggest Important Value Index (INP in intercropping agroforestry system is in trees level bymango at 59.46%, scrubs and sapling level by teak at 80.13%, seddling level by gosh bean at 49.57%.The biggest INP in Alley Cropping Agroforestry System is in trees level by cashew at 150.33%, scrubsand saplings level by lamtoro at 95.26%, seedling level by legetan at 84,93%. The biggest INP in TheTrees for Soil Conservations Agroforestry System is in trees level by tamarind at 165,35%, %, scrubsand saplings level by india apple at 114.09%, seedling level by legetan at 83.98%. The calculations ofspecies biodiversity which as species variety, prevalent index, and domination index can separated themanagement level in each agroforestry system. The best management is Intercropping AgroforestrySystem. The second is The Trees for Soil Conservations Agroforestry System. The last is Alley CroppingAgroforestry System. The development of Intercropping Agroforestry System is needed because thissystem is the best. Monitoring, evaluations, and technical learning about forest and agricultural

  13. Warming drives a front of white spruce establishment near western treeline, Alaska.

    Science.gov (United States)

    Miller, Amy E; Wilson, Tammy L; Sherriff, Rosemary L; Walton, James

    2017-12-01

    Regional warming has led to increased productivity near the boreal forest margin in Alaska. To date, the effects of warming on seedling recruitment have received little attention, in spite of forecasted forest expansion. Here, we used stand structure and environmental data from 95 white spruce (Picea glauca) plots sampled across a longitudinal gradient in southwest Alaska to explore factors influencing spruce establishment and recruitment near western treeline. We used total counts of live seedlings, saplings, and trees, representing five life stages, to evaluate whether geospatial, climate, and measured plot covariates predicted abundance, using current abundance distributions as a surrogate for climate conditions in the past. We used generalized linear models to test the null hypothesis that conditions favorable for recruitment were similar along the environmental gradient represented by longitude, by exploring relationships between per-plot counts of each life stage and the covariates hypothesized to affect abundance. We also examined the relationship between growing degree days (GDD) and seedling establishment over a period of three decades using tree-ring chronologies obtained from cores taken at a subset of our sites (n = 30). Our results indicated that seedling, sapling, and tree abundance were positively correlated with temperature across the study area. The response to longitude was mixed, with earlier life stages (seedlings, saplings) most abundant at the western end of the gradient, and later life stages (trees) most abundant to the east. The differential relationship between longitude and life-stage abundance suggests a moving front of white spruce establishment through time, driven by changes in environmental conditions near the species' western range limit. Likewise, we found a positive relationship between periods of seedling establishment and GDD, suggesting that longer summers and/or greater heat accumulation might enhance establishment

  14. Extraction of the growth regulator uniconazole (XE-1019) from silver maple wood

    Energy Technology Data Exchange (ETDEWEB)

    Arron, G.P.

    1990-11-30

    Growth regulators have been reported to inhibit the growth of many plant species, including trees. Application of such products to trees under or beside distribution lines may result in a reduction of the frequency of trimming of such trees. Silver maple saplings were trunk-injected with the growth regulator uniconazole ({sup 14}C-labelled). The proportion of uniconazole and metabolites in sapling wood from close to the injection site, harvested 0, 134 and 500 days after trunk injection, was determined. Between 95 and 97% of the {sup 14}C-activity found in this wood chromatographed with uniconazole, indicating little or no metabolism of the growth regulator had occurred over 500 days. In foliage from saplings harvested at 133 and 497 days slightly less of the {sup 14}C-activity chromatographed with uniconazole. The proportion of {sup 14}C-activity that was extracted from this wood by various solvents was also determined. Water extracted about 20% of the {sup 14}C-activity from day 0 wood in a 30 second incubation experiment, but only about 10% of the activity from day 134 or day 500 wood. With longer incubation times there was no difference. The time of harvest also had no effect on the proportion of {sup 14}C-activity extracted by various organic solvents. Nonpolar solvents extracted a larger proportion of the activity in day 0 wood than from day 134 or day 500 wood. The proportion of {sup 14}C-activity that was extracted by the various solvents did not change either as a function of the initial amount of {sup 14}C-activity in the wood, or the time of harvest of the wood. This would suggest that as a result of translocation, the percentage of uniconazole available for translocation remains constant. 26 refs., 2 figs., 7 tabs.

  15. Spectral and physiological information from chlorophyll fluorescence signals in the detection of pine damage

    Energy Technology Data Exchange (ETDEWEB)

    Meinander, O. [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Dept.; Somersalo, S. [Helsinki Univ., Helsinki (Finland). Dept. of Plant Biology

    1995-12-31

    Photosynthesis is often among the first targets of the air pollution stress of plants. As chlorophyll fluorescence is a process competing with photosynthetic electron transport it can be employed to study the potential photosynthetic capacity and to detect damage to the photosynthetic apparatus. Many previous studies have shown that chlorophyll fluorescence can be a powerful tool in the detection of forest damage. In this preliminary study, singular value analysis of the fluorescence induction curves was used together with the traditional way of analyzing fluorescence measurements. The experimental data were collected from ozone and carbon dioxide fumigated Scots pine saplings. (author)

  16. Translations of JEN-MIN JIH-PAO Articles on Sociological and Economic Subjects

    Science.gov (United States)

    1960-06-23

    was improved, the. domestic animals were successfully reaered 3anc1 the fruit trees bsgaa to take root. Today the farm raises 2,000 hogs, and...the workers succeeded in inventing a. new method for the growth of saplings, by ’-rafting an apply eaplißg- on a branch of a hai-tang tree; / malus ...and’popularized .•rood strains of crops, fruit trees, vegetables and domestic animals, new tools and new technical achievements. ■ ixeeently we

  17. Quantitative Analysis of Tree Species in Mixed Forests of Mandal Catchments, Garhwal Himalaya

    Directory of Open Access Journals (Sweden)

    Balwant KUMAR

    2012-06-01

    Full Text Available A total of 14 tree species were identified in the study sites, among which Quercus leucotrichophora Hook. F. (Banj oak, Rhododendron arboreum Smith (Burans, Lyonia ovalifolia Drude (Ayar and Pyrus pashia Buch-Hemp (Mehal are the predominant tree species. A quantitative analysis of tree species indicates that on the basis of their canopy cover, tree density and total base area, these study sites fall within the category of disturbed forest. The uncontrolled lopping for timber, firewood and leaf fodder and the absence of saplings and seedlings are some of the major factors responsible for the declining of forests in the Himalayan region.

  18. Root proteome response to growth on tannery waste in three different poplar species with various adaptation abilities

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    Zemleduch-Barylska A.

    2013-04-01

    Full Text Available In our study we compared growth of three poplar clones (Populus tremula ×alba, P. alba ‘Villafranca” and P. nigra on chromium-containing solid tannery waste. Tolerance index of saplings ranged from only 25% for P. nigra up to 80% for P. tremula x alba. Standard morphological, chemical and biochemical analyses also confirmed significant differences in reaction of all tested clones to such growth conditions. Preliminary proteomic study showed an unequal level of changes in protein profiles from roots in different poplars.

  19. Installation Restoration Program. Phase II--Confirmation/Quantification. Stage 1.

    Science.gov (United States)

    1985-03-01

    Groun&dater Samples Surface Water and Sedinent Saples Depth to water surface 5 3 Tota p4:h___________ Height of water colum Sale Depth - Sp. co. 29...Location Descriptioni: WS (I- 3 Groundwater Samples Surface Water and Sedinet Saiples Depth to wter surface Tota h Heiht of water colum Sample Depth(s...SFt,...,AGE LAGO o0o - /EST Groundwater Samples S’ fae Water and Sedimnt Samples 3/12-/;Y Depth to water surface 7"Total Depth Height of water

  20. Forest succession at elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Clark, James S.; Schlesinger, William H.

    2002-02-01

    We tested hypotheses concerning the response of forest succession to elevated CO2 in the FACTS-1 site at the Duke Forest. We quantified growth and survival of naturally recruited seedlings, tree saplings, vines, and shrubs under ambient and elevated CO2. We planted seeds and seedlings to augment sample sites. We augmented CO2 treatments with estimates of shade tolerance and nutrient limitation while controlling for soil and light effects to place CO2 treatments within the context of natural variability at the site. Results are now being analyzed and used to parameterize forest models of CO2 response.

  1. Palms, peccaries and perturbations: widespread effects of small-scale disturbance in tropical forests

    Directory of Open Access Journals (Sweden)

    Queenborough Simon A

    2012-03-01

    Full Text Available Abstract Background Disturbance is an important process structuring ecosystems worldwide and has long been thought to be a significant driver of diversity and dynamics. In forests, most studies of disturbance have focused on large-scale disturbance such as hurricanes or tree-falls. However, smaller sub-canopy disturbances could also have significant impacts on community structure. One such sub-canopy disturbance in tropical forests is abscising leaves of large arborescent palm (Arececeae trees. These leaves can weigh up to 15 kg and cause physical damage and mortality to juvenile plants. Previous studies examining this question suffered from the use of static data at small spatial scales. Here we use data from a large permanent forest plot combined with dynamic data on the survival and growth of > 66,000 individuals over a seven-year period to address whether falling palm fronds do impact neighboring seedling and sapling communities, or whether there is an interaction between the palms and peccaries rooting for fallen palm fruit in the same area as falling leaves. We tested the wider generalisation of these hypotheses by comparing seedling and sapling survival under fruiting and non-fruiting trees in another family, the Myristicaceae. Results We found a spatially-restricted but significant effect of large arborescent fruiting palms on the spatial structure, population dynamics and species diversity of neighbouring sapling and seedling communities. However, these effects were not found around slightly smaller non-fruiting palm trees, suggesting it is seed predators such as peccaries rather than falling leaves that impact on the communities around palm trees. Conversely, this hypothesis was not supported in data from other edible species, such as those in the family Myristicaceae. Conclusions Given the abundance of arborescent palm trees in Amazonian forests, it is reasonable to conclude that their presence does have a significant, if spatially

  2. Felling Ficus

    DEFF Research Database (Denmark)

    Cotee-Jones, H. Eden W.; Whitaker, Robert J.

    2015-01-01

    mixed and sometmes contradictory understandings of the religious atributes of fig trees, which were sometmes believed to be inhabited by gods or ancestral spirits. The benefits most commonly associated with fig trees by interviewees were their aesthetc beauty, large size, and shade during the daytme...... heat. When the presence of these trees incurred economic costs, their religious, aesthetc, and practcal benefits were not sufficient reasons to prevent people from cutng them down, although often saplings would be planted in another place as compensaton. Unexpectedly, figs were only planted...

  3. The life of a dead ant -the expression of an adaptive extended phenotype

    DEFF Research Database (Denmark)

    Andersen, Sandra Breum; Gerritsma, Sylvia; Yusah, Kalsum M.

    2009-01-01

    to make hosts bite onto vegetation prior to killing them. We show that this represents a fine-tuned fungal adaptation: an extended phenotype. Dead ants were found under leaves, attached by their mandibles, on the northern side of saplings ca. 25 cm above the soil, where temperature and humidity conditions...... were optimal for fungal growth. Experimental relocation confirmed that parasite fitness was lower outside this manipulative zone. Host resources were rapidly colonized and further secured by extensive internal structuring. Nutritional composition analysis indicated that such structuring allows...

  4. Chemistry Wastewater Treatment of El-Oued City (South-East of Algeria) by Utilization of Typha Latifolia

    OpenAIRE

    Zeghdi Saad; Bebba Ahmed Abdelhafid; Laouini Salah Eddine

    2016-01-01

    The objective of this study is to show the potential of Typha latifolia in the Purification performance of wastewater in the region of El Oued (southeast of Algeria). The pilot scale consists of two beds of plastics, filled with gravel and sand. One was planted saplings Typha latifolia at 36 stems/m2, the second was not planted serves as a control (witness). The results show good yields for suspended solids and organic pollution, removal rates are 96,76% for (SS) 89,92% for the Chemical Oxyge...

  5. The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen

    Energy Technology Data Exchange (ETDEWEB)

    Maja, Mengistu M., E-mail: mengistu.maja@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Kasurinen, Anne; Holopainen, Toini [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Julkunen-Tiitto, Riitta [University of Eastern Finland, Department of Biology, P.O. Box 111, 80101 Joensuu (Finland); Holopainen, Jarmo K. [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland)

    2016-03-15

    Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient + 2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A + T and UV-B + T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B × temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone

  6. Lophodermium piceae and Rhizosphaera kalkhoffi i in Norway spruce: correlations with host age and climatic features

    Directory of Open Access Journals (Sweden)

    L. Scattolin

    2009-09-01

    Full Text Available The study was carried out in 4 similar Norway spruce stands and it demonstrated that the spreading structures produced by Lophodermium piceae and Rhizosphaera kalkhoffii are not correlated. The two fungi were always detected with opposite growth trends, probably due to different needle colonization and spreading strategies, and this was most likely also why they were able to co-exist, colonizing different parts of the needle. Independently of the year, site, sampling period and amount of precipitation, the two fungi were significantly less common in saplings and more common in mature trees, with frequencies also depending on both the minimum and the maximum temperatures.

  7. REFERENCED TECHNOLOGICAL PERFORMANCES FOR STURGEON FINGERLING BREEDING IN INTENSIVE SYSTEM

    Directory of Open Access Journals (Sweden)

    MARILENA TALPES

    2008-10-01

    Full Text Available Work objective is to present an oversight regarding the modality to rearing the descendents of anadromous sturgeon species, Acipenser stellatus, Acipenser gueldenstaedti and Huso huso, obtained trough artificial reproduction, indicating successively, the production system, its management, alimentation strategy for sturgeon species and technological performances registered by these. Experiments developed during two phases, respectively the post-embryonary one and sapling rearing during of a 168 days period. Registered performances of sturgeon species material were assessed in conformity with specifically biotechnological indicators.

  8. National Program for Inspection of Non-Federal Dams, Thames River Basin, Norwich, Connecticut, Spaulding Pond Dam (CT 00202), Spaulding Pond Dike (CT 01685). Phase I Inspection Report.

    Science.gov (United States)

    1980-08-01

    slopes is not mowed, but any brush or saplings which take root are cut down. Maintenance to the roadway, guard rail and chain link fence on the crest of...fraction predominated to refusal. Artesian conditiogs were detected at the approximate bedrock level. Water rose to . a lie ht .f 1.2 teet in the...ow: per toot. Refusal wir at 27.8 feet whereupon at well rractured poise was pentrated. Hole 304 was located about 90 teet below the eutterliue at

  9. Genetic consequences of habitat fragmentation in long-lived tree species: the case of the mediterranean Holm Oak (Quercus ilex, L.).

    Science.gov (United States)

    Ortego, Joaquín; Bonal, Raúl; Muñoz, Alberto

    2010-01-01

    Large-scale forest fragmentation can increase interpopulation genetic differentiation and erode the genetic variability of remnant plant populations. In this study, we analyze the extent of clonality and the genetic variability and structure within a holm oak (Quercus ilex) population from Central Spain at 3 patches showing different degrees of fragmentation. For this purpose, we have typed 191 individuals (105 adults and 86 saplings) at 9 microsatellite loci. Microsatellite markers revealed an extensive clonal structure in this species, with most analyzed clumps constituting a single "genet", which in some cases extended over a considerable area (up to 318 m(2)). The maximum distance between "ramets" tended to be higher in the extremely fragmented patch, suggesting that intensive management and environmental perturbation has favored clonal propagation. We have also found evidence that fragmentation has contributed to reduce genetic variability and increase genetic differentiation in holm oak saplings, indicating that the younger cohorts are suffering some negative genetic consequences of long-term population fragmentation. Finally, analyses of fine spatial genetic structure have revealed significant kinship structures up to 20-50 m that were particularly patent in the 2 less fragmented patches. Overall, our findings point to long-term genetic shifts in population structure of holm oaks in fragmented landscapes; however, further research is required on pollen dispersal and gene flow in this species.

  10. Effects of Repeated Growing Season Prescribed Fire on the Structure and Composition of Pine–Hardwood Forests in the Southeastern Piedmont, USA

    Directory of Open Access Journals (Sweden)

    Matthew J. Reilly

    2016-12-01

    Full Text Available We examined the effects of repeated growing season prescribed fire on the structure and composition of mixed pine–hardwood forests in the southeastern Piedmont region, Georgia, USA. Plots were burned two to four times over an eight-year period with low intensity surface fires during one of four six-week long periods from early April to mid-September. Density of saplings (0.25–11.6 cm diameter at breast height was significantly reduced after one or two fires during the first four-year period. Sapling density declined with additional burning over the next four years, but density of mesic hardwoods including sweetgum (Liquidambar styraciflua and red maple (Acer rubrum remained relatively high (~865 stems ha−1. Repeated burning had little effect on density or basal area of trees (≥11.7 cm dbh and changes in overstory structure were limited to small increases in the quadratic mean diameter of all trees and pines. We found little evidence to suggest differential effects on structure or composition due to timing of burn within the growing season. Although repeated growing season burning alters midstory structure and composition, burning alone is unlikely to result in immediate shifts in overstory composition or structure in mixed pine–hardwood forests of the southeastern Piedmont region.

  11. [Effects of light intensity heterogeneity in gaps of broadleaved Korean pine forest in Changbai Mountains on Pinus koraiensis seedings growth].

    Science.gov (United States)

    Wang, Zhuo; Fan, Xiu-Hua

    2009-05-01

    By using a Li-6400 portable photosynthesis system, this paper studied the heterogeneity of light intensity in four different size gaps of a broadleaved Korean pine forest in Changbai Mountains, and analyzed the diurnal change of the photosynthesis of Pinus koraiensis saplings in the gaps. In the nine orientations within the gaps, the peak value of the photosynthetically active radiation (PAR) varied in the sequence of west of actual gap, north of extended gap, gap center > south of actual gap, south of extended gap, east of extended gap, east of actual gap > west of extended gap, north of actual gap. Light distribution was dissymmetry in the orientations of east-west and south-north, with the variation in west and north being more significant than that in other orientations. There was no significant difference in the average PAR among the positions within specific orientations. The average PAR of the four gaps from I to IV was 21.85, 45.57, 66.02, and 23.48 micromol x m(-2) x s(-1), respectively, and the difference was statistically significant (P rate (P(n)), and the correlation coefficient increased with increasing PAR. With the increase of gap size, both the PAR and the P(n) of P. koraiensis saplings increased first and decreased then, with the maximum values appeared at 267 m2 of gap size.

  12. Sexual regeneration traits linked to black cherry ( Prunus serotina Ehrh.) invasiveness

    Science.gov (United States)

    Pairon, Marie; Chabrerie, Olivier; Casado, Carolina Mainer; Jacquemart, Anne-Laure

    2006-09-01

    In order to better understand the invasive capacity of black cherry ( Prunus serotina Ehrh.), the regeneration dynamics of the species was studied during two consecutive years in a Belgian Pine plantation. Flower and fruit production, seed rain, dispersal and viability as well as the survival of seedlings of different ages were assessed. Despite the low fruit/flower ratio, fruit production was high (up to 8940 fruits per tree) as trees produced huge quantities of flowers. Both flower and fruit productions were highly variable between years and among individuals. The production variability between individuals was not correlated with plant size variables. Fruits were ripe in early September and a majority fell in the vicinity of the parent tree. A wide range of bird species dispersed 18% of the fruits at the end of October. Sixty-two percent of the fruits were viable and mean densities of 611 fruits m -2 were recorded on the forest floor. High mortality among young seedlings was observed and 95.3% of the fruits failed to give 4-year-old saplings. Nevertheless, the few saplings older than 4 years (1.32 m -2) presented a high survival rate (86%). All these regeneration traits are discussed in order to determine the main factors explaining the black cherry invasive success in Europe.

  13. Ectomycorrhizal fungal response to warming is linked to poor host performance at the boreal-temperate ecotone.

    Science.gov (United States)

    Fernandez, Christopher W; Nguyen, Nhu H; Stefanski, Artur; Han, Ying; Hobbie, Sarah E; Montgomery, Rebecca A; Reich, Peter B; Kennedy, Peter G

    2017-04-01

    Rising temperatures associated with climate change have been shown to negatively affect the photosynthetic rates of boreal forest tree saplings at their southern range limits. To quantify the responses of ectomycorrhizal (EM) fungal communities associated with poorly performing hosts, we sampled the roots of Betula papyrifera and Abies balsamea saplings growing in the B4Warmed (Boreal Forest Warming at an Ecotone in Danger) experiment. EM fungi on the root systems of both hosts were compared from ambient and +3.4 °C air and soil warmed plots at two sites in northern Minnesota. EM fungal communities were assessed with high-throughput sequencing along with measures of plant photosynthesis, soil temperature, moisture, and nitrogen. Warming selectively altered EM fungal community composition at both the phylum and genus levels, but had no significant effect on EM fungal operational taxonomic unit (OTU) diversity. Notably, warming strongly favored EM Ascomycetes and EM fungi with short-contact hyphal exploration types. Declining host photosynthetic rates were also significantly inversely correlated with EM Ascomycete and EM short-contact exploration type abundance, which may reflect a shift to less carbon demanding fungi due to lower photosynthetic capacity. Given the variation in EM host responses to warming, both within and between ecosystems, better understanding the link between host performance and EM fungal community structure will to clarify how climate change effects cascade belowground. © 2016 John Wiley & Sons Ltd.

  14. Spread of the Introduced Sitka Spruce (Picea sitchensis in Coastal Norway

    Directory of Open Access Journals (Sweden)

    Per Holm Nygaard

    2017-01-01

    Full Text Available Positive and negative effects on ecosystem services from plantation forestry in Europe have led to conflicts regarding non-native tree species. Sitka spruce (Picea sitchensis (Bong. Carr. is the most common plantation species in northwest Europe, covering 1.3 Mha. In costal Norway, Sitka spruce was intentionally introduced and is currently occupying about 50,000 ha. Sitka spruce was blacklisted in Norway in 2012, mainly based on the risk for invasive spreading, but little quantitative documentation exists on spread. Here we quantify spread from plantations into abandoned heathland and pastures in thirteen sites where natural regeneration occurs. Spread distances and zero-square distributions related to the nearest edge of the parent stand were fitted by use of Weibull. The median expansion rate was 0.8 m·year−1 in north Norway and 4.4 m·year−1 in west Norway. The maximum establishment distance measured was 996 m. A peak in sapling density occurred within 50 m from the edge, and there was a general decrease in saplings with increasing distance. Conversely, increase in zero-squares percentages occurred with increasing distance. We argue that inclusion of abundance in assessing spread is necessary to define invasiveness. Based on spread models and prevailing forestry practices we recommend that the establishment of new Sitka spruce plantations within 200 m of protected areas should be avoided.

  15. Assessment of spatial discordance of primary and effective seed dispersal of European beech (Fagus sylvatica L.) by ecological and genetic methods.

    Science.gov (United States)

    Millerón, M; López de Heredia, U; Lorenzo, Z; Alonso, J; Dounavi, A; Gil, L; Nanos, N

    2013-03-01

    Spatial discordance between primary and effective dispersal in plant populations indicates that postdispersal processes erase the seed rain signal in recruitment patterns. Five different models were used to test the spatial concordance of the primary and effective dispersal patterns in a European beech (Fagus sylvatica) population from central Spain. An ecological method was based on classical inverse modelling (SSS), using the number of seed/seedlings as input data. Genetic models were based on direct kernel fitting of mother-to-offspring distances estimated by a parentage analysis or were spatially explicit models based on the genotype frequencies of offspring (competing sources model and Moran-Clark's Model). A fully integrated mixed model was based on inverse modelling, but used the number of genotypes as input data (gene shadow model). The potential sources of error and limitations of each seed dispersal estimation method are discussed. The mean dispersal distances for seeds and saplings estimated with these five methods were higher than those obtained by previous estimations for European beech forests. All the methods show strong discordance between primary and effective dispersal kernel parameters, and for dispersal directionality. While seed rain was released mostly under the canopy, saplings were established far from mother trees. This discordant pattern may be the result of the action of secondary dispersal by animals or density-dependent effects; that is, the Janzen-Connell effect. © 2013 Blackwell Publishing Ltd.

  16. Vapor-pressure deficit and extreme climatic variables limit tree growth.

    Science.gov (United States)

    Sanginés de Cárcer, Paula; Vitasse, Yann; Peñuelas, Josep; Jassey, Vincent E J; Buttler, Alexandre; Signarbieux, Constant

    2017-11-03

    Assessing the effect of global warming on forest growth requires a better understanding of species-specific responses to climate change conditions. Norway spruce and European beech are among the dominant tree species in Europe and are largely used by the timber industry. Their sensitivity to changes in climate and extreme climatic events, however, endangers their future sustainability. Identifying the key climatic factors limiting their growth and survival is therefore crucial for assessing the responses of these two species to ongoing climate change. We studied the vulnerability of beech and spruce to warmer and drier conditions by transplanting saplings from the top to the bottom of an elevational gradient in the Jura Mountains in Switzerland. We (1) demonstrated that a longer growing season due to warming could not fully account for the positive growth responses, and the positive effect on sapling productivity was species-dependent, (2) demonstrated that the contrasting growth responses of beech and spruce were mainly due to different sensitivities to elevated vapor-pressure deficits (VPD), (3) determined the species-specific limits to VPD above which growth rate began to decline, and (4) demonstrated that models incorporating extreme climatic events could account for the response of growth to warming better than models using only average values. These results support that the sustainability of forest trees in the coming decades will depend on how extreme climatic events will change, irrespective of the overall warming trend. © 2017 John Wiley & Sons Ltd.

  17. Evidence of a higher late-Holocene treeline along the Continental Divide in central Colorado

    Science.gov (United States)

    Carrara, Paul E.; McGeehin, John

    2015-01-01

    Using a combination of 23 radiocarbon ages and annual ring counts from 18 Rocky Mountain bristlecone pine (Pinus aristata) remnants above the local present-day limits, a period of higher treeline has been determined for two sites near the Continental Divide in central Colorado. The highest remnants were found about 30 m above live bristlecone pines of similar size. The majority of the remnants, consisting of standing snags, large logs, and smaller remains, are highly eroded, such that the innermost annual rings of all but one are missing. The radiocarbon ages obtained from the oldest wood recovered from each remnant indicate that the majority were established above the present-day limit of bristlecone pine from prior to 2700 cal. yr BP to no later than about 1200 cal. yr BP. These radiocarbon ages combined with the annual ring count from the corresponding remnant indicate that the majority of the sampled remnants grew above the present-day limit of bristlecone pine from sometime before 2700 cal. yr BP to about 800 cal. yr BP. Evidence of recent climatic warming is demonstrated at one of the sites by young bristlecone pine saplings growing next to the highest remnants; the saplings were established after AD 1965 and represent the highest advance of treeline in at least 1200 years.

  18. Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest.

    Directory of Open Access Journals (Sweden)

    Guodong Jia

    Full Text Available Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined.

  19. Natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China.

    Directory of Open Access Journals (Sweden)

    Xitian Yang

    Full Text Available Natural regeneration is the natural process by which plants replace themselves. It is a cost-effective way to re-establish vegetation, and it helps to preserve genetic identity and diversity. In this study, we investigated the natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China, which were dominated by Robinia pseudoacacia (black locust, Quercus variabilis (Chinese cork oak and Platycladus orientalis (Chinese arborvitae respectively. A consistent pattern was found among the three types of stands, being that the density of seedlings was positively correlated with the overstory canopy cover and negatively correlated with the covers of shrub, herb and litter layers. While a positive correlation between the density of seedlings and stand age was found for the conifer stands, negative correlations were found for the two types of broadleaf stands. Correlations between the density of saplings and the stand attributes were not consistent among the three types of stands. The two types of broadleaf stands had higher densities of seedlings and saplings than the conifer stands. While the broadleaf stands had adequate recruits for regeneration, the conifer stands did not have enough recruits. Our findings suggest that the overstory canopy should be prevented from being disturbed, any reduction of the canopy cover will decrease the recruits and affect the regeneration.

  20. Effect of the application of water hyacinth compost/vermicompost on the growth and flowering of Crossandra undulaefolia, and on several vegetables.

    Science.gov (United States)

    Gajalakshmi, S; Abbasi, S A

    2002-11-01

    The impact of the application of compost/vermicompost obtained from water hyacinth (Eichhornia crassipes, Mart. Solms) on plants was assessed in terms of growth and flowering of the angiosperm crossandra (Crossandra undulaefolia). Overall nine morphological, size, and yield attributes were studied in crossandra saplings raised on water hyacinth compost or vermicompost as compared to the untreated saplings. Application of vermicompost led to statistically significant improvement in the growth and flowering of crossandra compared to the untreated plants. The impact of compost was also beneficial but a little less distinct than the positive impact of vermicompost. Qualitative studies were simultaneously conducted in five kitchen gardens owned by farmers near Pondicherry. In three of these locations water hyacinth vermicompost was applied-and no other fertilizer-for months to different species of vegetables. Water hyacinth compost was similarly applied in another two locations. In all the locations no adverse effect on any of the plant species was observed. We believe these studies would help in dispelling the apprehension of farmers that compost/vermicompost obtained form a pernicious weed like water hyacinth may have deleterious effect on other plants.

  1. PHOTOSYNTHETIC RESPONSES OF Eucalyptus nitens Maiden AT INITIAL STAGES OF ROOT-ROT INFECTION

    Directory of Open Access Journals (Sweden)

    Luciasih Agustini

    2015-04-01

    Full Text Available Root-rots are known to be latent diseases that may be present in plants for an extended period without any noticeable expression of symptoms above ground. Photosynthetic responses of Eucalyptus nitens saplings artificially inoculated with the root-rot pathogen, Armillaria luteobubalina were examined to characterize the initial stages of root-rot infection. This paper studies three photosynthetic parameters, i.e. photosystem II yield (Fv/Fm, chlorophyll content and photosynthetic capacity (Amax for two strains of A. luteobubalina over a seven-month period. Root systems were either wounded or left intact before inoculation. A significant difference was observed in the Fv/Fm ratio between the uninoculated control and inoculated saplings. Photosystem II yield was considered the most sensitive parameter for the early detection of root-rot disease. Chlorophyll content and Amax decreased for all trees, including controls, during the period of the experiment, and most likely reflected host responses to seasonal change rather than treatment effects. Fungal re-isolations from symptomatic roots of inoculated trees confirmed the presence of A. luteobubalina. Findings from this preliminary trial indicated that there were detectable physiological changes associated with early infection of root-rot. However, to detect more widespread physiological changes an experiment of longer duration is needed.

  2. Effects of long-term elevated atmospheric CO{sub 2} concentrations on Pinus ponderosa

    Energy Technology Data Exchange (ETDEWEB)

    Surano, K.A.; Kercher, J.R. [eds.

    1993-10-01

    This report details the results from an experiment of the effects of long-term elevated atmospheric CO{sub 2} concentrations on ponderosa pine (Pinus ponderosa Laws.) saplings and seedlings. The study began in 1983 as a pilot study designed to explore the feasibility of using open-top chambers for continuous multi-year exposures on sapling-sized trees and to examine possible CO{sub 2} responses so that future research could be adequately designed. however, following the first year of exposure, preliminary results from the study indicated that measurements of CO{sub 2} responses should be intensified. Open-top chambers proved suitable for use in multiyear exposures of mature trees. With respect to the preliminary examination of CO{sub 2} responses, many interesting observations were made. The nature of the preliminary results suggests that future long-term field CO{sub 2} exposures on perennial species may be critical to the understanding and preparation for future environments. Other research reported here attempted to adapt an existing western coniferous forest growth and succession model for use in elevated CO{sub 2} scenarios using differential species responses, and assessed the usefulness of the model in that regard. Seven papers have been processed separately for inclusion in the appropriate data bases.

  3. The Challenge of Forest Diagnostics

    Directory of Open Access Journals (Sweden)

    Harini Nagendra

    2011-06-01

    Full Text Available Ecologists and practitioners have conventionally used forest plots or transects for monitoring changes in attributes of forest condition over time. However, given the difficulty in collecting such data, conservation practitioners frequently rely on the judgment of foresters and forest users for evaluating changes. These methods are rarely compared. We use a dataset of 53 forests in five countries to compare assessments of forest change from forest plots, and forester and user evaluations of changes in forest density. We find that user assessments of changes in tree density are strongly and significantly related to assessments of change derived from statistical analyses of randomly distributed forest plots. User assessments of change in density at the shrub/sapling level also relate to assessments derived from statistical evaluations of vegetation plots, but this relationship is not as strong and only weakly significant. Evaluations of change by professional foresters are much more difficult to acquire, and less reliable, as foresters are often not familiar with changes in specific local areas. Forester evaluations can instead better provide valid single-time comparisons of a forest with other areas in a similar ecological zone. Thus, in forests where local forest users are present, their evaluations can be used to provide reliable assessments of changes in tree density in the areas they access. However, assessments of spatially heterogeneous patterns of human disturbance and regeneration at the shrub/sapling level are likely to require supplemental vegetation analysis.

  4. Structure and Composition of a Dry Mixed-Conifer Forest in Absence of Contemporary Treatments, Southwest, USA

    Directory of Open Access Journals (Sweden)

    Douglas Cram

    2017-09-01

    Full Text Available Dry mixed-conifer forests in the Southwest occupy an important ecological and hydrological role in upper watersheds. In the absence of reoccurring fire and silvicultural treatments over the last 50 years, we quantified forest structure and composition on prevailing north and south aspects of a dry mixed-conifer forest in southcentral New Mexico using mixed models and ordination analysis in preparation for an experiment in ecological restoration. Results indicated overstory and midstory were dominated by Douglas-fir (Pseudotsuga menziesii and shade tolerant/fire intolerant white fir (Abies concolor with interspersed mature aspen on north aspects, and Douglas-fir and Southwestern white pine (Pinus strobiformis on south aspects. Ponderosa pine (Pinus ponderosa, which was historically co-dominant with Douglas-fir on north and south aspects, was subdominant on south aspects and almost entirely absent on north aspects. Regeneration was dominated by white fir saplings and seedlings on north aspects while ponderosa pine was completely absent. South aspect saplings and seedlings were characterized by Douglas-fir and Southwestern white pine, but almost no ponderosa pine. Ordination analysis characterized the effect of aspect on species composition. Understanding contemporary forest structure and composition is important when planning for desired future conditions that are to be achieved through ecological restoration using silvicultural techniques designed to foster resilience.

  5. Cloning and endogenous expression of a Eucalyptus grandis UDP-glucose dehydrogenase cDNA

    Directory of Open Access Journals (Sweden)

    Mônica T. Veneziano Labate

    2010-01-01

    Full Text Available UDP-glucose dehydrogenase (UGDH catalyzes the oxidation of UDP-glucose (UDP-Glc to UDP-glucuronate (UDP-GlcA, a key sugar nucleotide involved in the biosynthesis of plant cell wall polysaccharides. A full-length cDNA fragment coding for UGDH was cloned from the cambial region of 6-month-old E. grandis saplings by RT-PCR. The 1443-bp-ORF encodes a protein of 480 amino acids with a predicted molecular weight of 53 kDa. The recombinant protein expressed in Escherichia coli catalyzed the conversion of UDP-Glc to UDP-GlcA, confirming that the cloned cDNA encodes UGDH. The deduced amino acid sequence of the cDNA showed a high degree of identity with UGDH from several plant species. The Southern blot assay indicated that more than one copy of UGDH is present in Eucalyptus. These results were also confirmed by the proteomic analysis of the cambial region of 3- and 22-year-old E. grandis trees by 2-DE and LC-MS/MS, showing that at least two isoforms are present. The cloned gene is mainly expressed in roots, stem and bark of 6-month-old saplings, with a lower expression in leaves. High expression levels were also observed in the cambial region of 3- and 22-year-old trees. The results described in this paper provide a further view of the hemicellulose biosynthesis during wood formation in E. grandis.

  6. Vegetation Structure of Ebony Leaf Monkey (Trachypithecus auratus) Habitat in Kecubung Ulolanang Nature Preservation Central Java-Indonesia

    Science.gov (United States)

    Ervina, Rahmawati; Wasiq, Hidayat Jafron

    2018-02-01

    Kecubung Ulolanang Nature Preservation is ebony leaf monkey's habitats in Central Java Indonesia. Continuously degradation of their population is caused by illegal hunting and habitat degradation that made this species being vulnerable. Habitat conservation is one of important aspects to prevent them from extinction. The purpose of this research was to analyze the vegetation's structure and composition, which was potentially, becomes habitat and food source for the monkeys. Data collected using purposive sampling with line transect method of four different level of vegetation. Data analysis used Important Value Index and Diversity Index. There were 43 species of vegetation at seedling stage, 18 species at sapling stage, 8 species at poles stage and 27 species at trees stage. Species that had the highest important value index at seedling was Stenochlaena palustri , at the sapling was Gnetum gnemon, at pole was Swietenia mahagoni and at tree was Tectona grandis . Species of trees those were potentially to become habitat (food source) for ebony leaf monkey were T. grandis, Dipterocarpus gracilis, Quercus sundaica and Ficus superba. The highest diversity index was at seedling gwoth stage.

  7. Recruitment dynamics of the tropical rainforest tree Dipteryx oleifera (Fabaceae in eastern Nicaragua

    Directory of Open Access Journals (Sweden)

    Javier Ruiz

    2009-06-01

    Full Text Available Seed production, seed dispersal and recruitment are critical processes in population dynamics, because they are almost never completely successful. We recorded the recruitment dynamics for the population of Dipteryx oleifera in a tropical rainforest in eastern Nicaragua (12°05’ N., 83°55’ W. from March 2002 to August 2006. Seeds and seedlings had highly clumped distributions, while sapling distributions appeared to be random. Seedling survival increased away from the nearest conspecifc adult tree, where seedling density is lower. Since relative growth rates of seedlings are not correlated with the distance to the nearest conspecific adult, seedling survival appears to be independent of seedling growth. Seedling density is inversely correlated with seedling insect herbivory damage. Seedling survival correlated negatively with the number of saplings per sub-plot (10x10m, suggesting that insect herbivore may also cue in on saplings rather than only on adult D. oleifera trees in order to locate seedlings. Seedling establishment is significantly clumped with respect to the nearest adult tree. Larger clumps of seedlings seems more ephemeral than isolated smaller clumps located away from the nearest D. oleifera tree. These results support current empirical evidence presented earlier for the Janzen-Connell hypothesis for Dipteryx oleifera at seed and seedling stages and, the Recruitment Limitation hypothesis at the sapling stage, because sapling individuals might have recruited after random light-gap formation. Rev. Biol. Trop. 57 (1-2: 321-338. Epub 2009 June 30.Resumen Estudiamos la dinámica de regeneración de la población de Dipteryx oleifera en un bosque húmedo tropical del este de Nicaragua. Semillas y plántulas se encuentran altamente agregadas, pero la distribución de vástagos podría ser al azar. La supervivencia de plántulas aumenta con la distancia al congéner más cercano, donde la densidad de plántulas es más baja. Como las

  8. Unsaturated phosphatidylcholines lining on the surface of cartilage and its possible physiological roles

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    Crawford Ross W

    2007-08-01

    Full Text Available Abstract Background Evidence has strongly indicated that surface-active phospholipid (SAPL, or surfactant, lines the surface of cartilage and serves as a lubricating agent. Previous clinical study showed that a saturated phosphatidylcholine (SPC, dipalmitoyl-phosphatidylcholine (DPPC, was effective in the treatment of osteoarthritis, however recent studies suggested that the dominant SAPL species at some sites outside the lung are not SPC, rather, are unsaturated phosphatidylcholine (USPC. Some of these USPC have been proven to be good boundary lubricants by our previous study, implicating their possible important physiological roles in joint if their existence can be confirmed. So far, no study has been conducted to identify the whole molecule species of different phosphatidylcholine (PC classes on the surface of cartilage. In this study we identified the dominant PC molecule species on the surface of cartilage. We also confirmed that some of these PC species possess a property of semipermeability. Methods HPLC was used to analyse the PC profile of bovine cartilage samples and comparisons of DPPC and USPC were carried out through semipermeability tests. Results It was confirmed that USPC are the dominant SAPL species on the surface of cartilage. In particular, they are Dilinoleoyl-phosphatidylcholine (DLPC, Palmitoyl-linoleoyl-phosphatidylcholine, (PLPC, Palmitoyl-oleoyl-phosphatidylcholine (POPC and Stearoyl-linoleoyl-phosphatidylcholine (SLPC. The relative content of DPPC (a SPC was only 8%. Two USPC, PLPC and POPC, were capable of generating osmotic pressure that is equivalent to that by DPPC. Conclusion The results from the current study confirm vigorously that USPC is the endogenous species inside the joint as against DPPC thereby confirming once again that USPC, and not SPC, characterizes the PC species distribution at non-lung sites of the body. USPC not only has better anti-friction and lubrication properties than DPPC, they also

  9. Post-fire wood management alters water stress, growth, and performance of pine regeneration in a Mediterranean ecosystem

    Science.gov (United States)

    Maranon-Jimenez, Sara; Castro, Jorge; Querejeta, José Ignacio; Fernandez-Ondono, Emilia; Allen, Craig D.

    2013-01-01

    Extensive research has focused on comparing the impacts of post-fire salvage logging versus those of less aggressive management practices on forest regeneration. However, few studies have addressed the effects of different burnt-wood management options on seedling/sapling performance, or the ecophysiological mechanisms underlying differences among treatments. In this study, we experimentally assess the effects of post-fire management of the burnt wood on the growth and performance of naturally regenerating pine seedlings (Pinus pinaster). Three post-fire management treatments varying in degree of intervention were implemented seven months after a high-severity wildfire burned Mediterranean pine forests in the Sierra Nevada, southeast Spain: (a) “No Intervention” (NI, all burnt trees left standing); (b) “Partial Cut plus Lopping” (PCL, felling most of the burnt trees, cutting off branches, and leaving all the biomass on site without mastication); and (c) “Salvage Logging” (SL, felling the burnt trees, piling up the logs and masticating the fine woody debris). Three years after the fire, the growth, foliar nutrient concentrations, and leaf carbon, nitrogen and oxygen isotopic composition (δ13C, δ18O and δ15N) of naturally regenerating seedlings were measured in all the treatments. Pine seedlings showed greatest vigor and size in the PCL treatment, whereas growth was poorest in SL. The nutrient concentrations were similar among treatments, although greater growth in the two treatments with residual wood present indicated higher plant uptake. Seedlings in the SL treatment showed high leaf δ13C and δ18O values indicating severe water stress, in contrast to significantly alleviated water stress indications in the PCL treatment. Seedling growth and physiological performance in NI was intermediate between that of PCL and SL. After six growing seasons, P. pinaster saplings in PCL showed greater growth and cone production than SL saplings. In summary

  10. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Science.gov (United States)

    Zeigenfuss, Linda C.; Binkley, Dan; Tuskan, Gerald A.; Romme, William H.; Yin, Tongming; DiFazio, Stephen; Singer, Francis J.

    2008-01-01

    Lack of recruitment and canopy replacement of aspen (Populus tremuloides) stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado have been a cause of concern for more than 70 years. We used a combination of traditional dendrochronology and genetic techniques as well as measuring the characteristics of regenerating and nonregenerating stands on the elk winter range to determine when and under what conditions and estimated elk densities these stands established and through what mechanisms they may regenerate. The period from 1975 to 1995 at low elevation on the east side had 80-95 percent fewer aspen stems than would be expected based on the trend from 1855 through 1965. The age structure of aspen in the park indicates that the interacting effects of fires, elk population changes, and livestock grazing had more-or-less consistent effects on aspen from 1855 to 1965. The lack of a significant change in aspen numbers in recent decades in the higher elevation and west side parts of the park supports the idea that the extensive effects of elk browsing have been more important in reducing aspen numbers than other factors. The genetic variation of aspen populations in RMNP is high at the molecular level. We expected to find that most patches of aspen in the park were composed of a single clone of genetically identical trees, but in fact just 7 percent of measured aspen patches consisted of a single clone. A large frequency of polyploid (triploid and tetraploid) genotypes were found on the low elevation, east-side elk winter range. Nonregenerating aspen stands on the winter range had greater annual offtake, shorter saplings, and lower density of mid-height (1.5-2.5 m) saplings than regenerating stands. Overwinter elk browsing, however, did not appear to inhibit the leader length of aspen saplings. The winter range aspen stands of RMNP appear to be highly resilient in the face of

  11. Woody lianas increase in dominance and maintain compositional integrity across an Amazonian dam-induced fragmented landscape.

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    Isabel L Jones

    Full Text Available Tropical forest fragmentation creates insular biological communities that undergo species loss and changes in community composition over time, due to area- and edge-effects. Woody lianas thrive in degraded and secondary forests, due to their competitive advantage over trees in these habitats. Lianas compete both directly and indirectly with trees, increasing tree mortality and turnover. Despite our growing understanding of liana-tree dynamics, we lack detailed knowledge of the assemblage-level responses of lianas themselves to fragmentation, particularly in evergreen tropical forests. We examine the responses of both sapling and mature liana communities to landscape-scale forest insularization induced by a mega hydroelectric dam in the Brazilian Amazon. Detailed field inventories were conducted on islands created during reservoir filling, and in nearby mainland continuous forest. We assess the relative importance of variables associated with habitat fragmentation such as area, isolation, surrounding forest cover, fire and wind disturbance, on liana community attributes including abundance, basal area, diversity, and composition. We also explore patterns of liana dominance relative to tree saplings and adults ≥10 cm diameter at breast height. We find that 1 liana community composition remains remarkably similar across mainland continuous forest and islands, regardless of extreme area- and edge- effects and the loss of vertebrate dispersers in the latter; and 2 lianas are increasing in dominance relative to trees in the sapling layer in the most degraded islands, with both the amount of forest cover surrounding islands and fire disturbance history predicting liana dominance. Our data suggest that liana communities persist intact in isolated forests, regardless of extreme area- and edge-effects; while in contrast, tree communities simultaneously show evidence of increased turnover and supressed recruitment. These processes may lead to lianas

  12. Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China

    Science.gov (United States)

    Tian, Di; Li, Peng; Fang, Wenjing; Xu, Jun; Luo, Yongkai; Yan, Zhengbing; Zhu, Biao; Wang, Jingjing; Xu, Xiaoniu; Fang, Jingyun

    2017-07-01

    Reactive nitrogen (N) increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m × 20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings), and ground-cover plants (ferns) according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height) of 5-10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha-1 yr-1) and N100 fertilized plots (100 kg N ha-1 yr-1), while the growth of median and large trees with a DBH of > 10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical forest, and that the limitation of other nutrients in the forest

  13. Effects of elevated CO2 on soil organic matter turnover and plant nitrogen uptake: First results from a dual labeling mesocosm experiment

    Science.gov (United States)

    Eder, Lucia Muriel; Weber, Enrico; Schrumpf, Marion; Zaehle, Sönke

    2017-04-01

    The response of plant growth to elevated concentrations of CO2 (eCO2) is often constrained by plant nitrogen (N) uptake. To overcome potential N limitation, plants may invest photosynthetically fixed carbon (C) into N acquiring strategies, including fine root biomass, root exudation, or C allocation to mycorrhizal fungi. In turn, these strategies may affect the decomposition of soil organic matter, leading to uncertainties in net effects of eCO2 on C storage. To gain more insight into these plant-soil C-N-interactions, we combined C and N stable isotope labeling in a mesocosm experiment. Saplings of Fagus sylvatica L. were exposed to a 13CO2 enriched atmosphere at near ambient (380 ppm) or elevated (550 ppm) CO2 concentrations for four months of the vegetation period in 2016. Aboveground and belowground net CO2 fluxes were measured separately and the 13C label enabled partitioning of total soil CO2 efflux into old, soil derived and new, plant-derived C. We used ingrowth cores to assess effects of eCO2on belowground C allocation and plant N uptake in more detail and in particular we evaluated the relative importance of ectomycorrhizal associations. In the soil of each sapling, ingrowth cores with different mesh sizes allowed fine roots or only mycorrhizal hyphae to penetrate. In one type of ingrowth core each, we incorporated fine root litter that was enriched in 15N. Additionally, total N uptake was estimated by using 15N enriched saplings and unlabeled control plants. We found that eCO2 increased aboveground net CO2 exchange rates by 19% and total soil respiration by 11%. The eCO2 effect for GPP and also for NPP was positive (+23% and +11%, respectively). By combining gaseous C fluxes with data on new and old C stocks in bulk soil and plants through destructive harvesting in late autumn 2016, we will be able to infer net effects of eCO2 on the fate of C in these mesocosms. Biomass allocation patterns can reveal physiological responses to high C availability under

  14. Simulation of oak early life history and interactions with disturbance via an individual-based model, SOEL.

    Science.gov (United States)

    Kellner, Kenneth F; Swihart, Robert K

    2017-01-01

    Early tree life history and demography are driven by interactions with the environment such as seed predation, herbivory, light availability, and drought. For oak (Quercus) in the eastern United States, these interactions may contribute to oak regeneration failure. Numerous studies have examined the impact of individual factors (like seed predation) on the oak regeneration process, but less information is available on the relative and combined impacts of multiple intrinsic and extrinsic factors on early oak life history. We developed an individual-based, spatially explicit model to Simulate Oak Early Life history (SOEL). The model connects acorn survival, acorn dispersal, germination, seedling growth, and seedling survival submodels based on empirical data with an existing gap model (JABOWA). Using SOEL, we assessed the sensitivity of several metrics of oak regeneration to different parameters associated with early oak life history. We also applied the model in three individual case studies to assess: (1) how variable acorn production interacts with timing of timber harvest; (2) the effect of shelterwood harvest-induced differences on seed predation; and (3) the consequences of interactions between drought, seedling growth and survival, and timber harvest. We found that oak regeneration metrics including percent emergence, seedling density, and sapling density were most sensitive to the amount of acorn production, acorn caching probability by scatterhoarders, and seedling growth rates. In the case studies, we found that timing harvest to follow large acorn crops can increase the density of oak regeneration in the short term following harvest, at least under some conditions. Following midstory removal, lower weevil infestation probability and lower post-dispersal acorn survival resulted in a modest decline in seedling density, but the decline did not persist to the sapling life stage class. Drought frequency had a powerful negative impact on both growth and survival

  15. Simulation of oak early life history and interactions with disturbance via an individual-based model, SOEL.

    Directory of Open Access Journals (Sweden)

    Kenneth F Kellner

    Full Text Available Early tree life history and demography are driven by interactions with the environment such as seed predation, herbivory, light availability, and drought. For oak (Quercus in the eastern United States, these interactions may contribute to oak regeneration failure. Numerous studies have examined the impact of individual factors (like seed predation on the oak regeneration process, but less information is available on the relative and combined impacts of multiple intrinsic and extrinsic factors on early oak life history. We developed an individual-based, spatially explicit model to Simulate Oak Early Life history (SOEL. The model connects acorn survival, acorn dispersal, germination, seedling growth, and seedling survival submodels based on empirical data with an existing gap model (JABOWA. Using SOEL, we assessed the sensitivity of several metrics of oak regeneration to different parameters associated with early oak life history. We also applied the model in three individual case studies to assess: (1 how variable acorn production interacts with timing of timber harvest; (2 the effect of shelterwood harvest-induced differences on seed predation; and (3 the consequences of interactions between drought, seedling growth and survival, and timber harvest. We found that oak regeneration metrics including percent emergence, seedling density, and sapling density were most sensitive to the amount of acorn production, acorn caching probability by scatterhoarders, and seedling growth rates. In the case studies, we found that timing harvest to follow large acorn crops can increase the density of oak regeneration in the short term following harvest, at least under some conditions. Following midstory removal, lower weevil infestation probability and lower post-dispersal acorn survival resulted in a modest decline in seedling density, but the decline did not persist to the sapling life stage class. Drought frequency had a powerful negative impact on both growth

  16. Conservation Threat Assessment of Commiphora wightii (Arn. Bhandari - an Economically Important Species

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    S. L. Meena

    2012-09-01

    Full Text Available In the present study, habitat, distribution and regeneration of Commiphora wightii (Arn. Bhandari (Burseraceae was explored in Rajasthan, India, to support conservation actions. Twenty-six sites were identified for sampling the populations of C. wightii in the desert region and in Aravallis. Commiphora wightii prefers rocky substratum and grows in shallow, gravelly, unfertile soils, hilly terrains and under open canopies. The number of saplings was only 5.68 % as compared to its adult population. Population densities of C. wightii were 25 stems ha-1 in desert and 40 stems ha-1 in Aravallis of Rajasthan, India. Over-exploitation, narrow extent of occurrence, small area of occupancy, severe fragmentation of populations, very low regeneration and invasion of alien species to its habitat revealed that C. wightii is facing severe conservation threat and extinction risk. It should be prioritized for “endangered category” by ensuring the habitat conservation, sustainable utilization and cultivation of this economically important species.

  17. Partial results regarding the selection of some nut tree hybrids in order to obtain generative mother plants

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    Eliane Teodora STANCIOIU

    2008-05-01

    Full Text Available In Romania, the establishment of nut tree plantations is continuously expanding, yet the seeding material production has never raised up to the level of cultivators requirements.In our country, although the mother plants are confirmed as Targu Jiu 1, Secular and recently Portval, because of lack of seed tree materials, at present, most of the varieties are being grafted on saplings proceeded from a mixture of genotypes belonging to the species of Juglans regia.By studying the rich stock of germoplasma, present in the district of Gorj, 20 hybrids, that have appropriate features to their formation as mother plants have been collected, so that they might improve the existing variety.

  18. FOREST DISTURBANCE LEADS TO THE RAPID SPREAD OF THE INVASIVE LEUCAENA LEUCOCEPHALA IN TAIWAN

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    J. C. Chen

    2012-07-01

    Full Text Available This study, based on different investigative documents and analytical methods, elucidates spatial distribution of habitats for major invasive exotic plants, Leucaena leucocephala, in Taiwan. Results show that Leucaena leucocephala is most harmful to broad-leaved trees and its invasion directly relates to changes in the physical environment. Leucaena leucocephala can bloom and bear fruits all year round and during the period of seeds sprouting and saplings, the invasion varies greatly among different soil types. Leucaena leucocephala prefers weakly acidic soil, though it grows well with other soil textures and nutrients as well. The average spreading rate of Leucaena leucocephala is 3.55 ha year−1 on abandoned farm land calculated from the aerial photographs taken in 1982, 1992, 2003, and 2007.

  19. Equivalence in the strength of deer herbivory on above and below ground communities

    DEFF Research Database (Denmark)

    Lessard, Jean-Philippe; Reynolds, W. Nicholas; Bunn, Windy A.

    2012-01-01

    that herbivory would alter the composition and diversity of communities, but the strength of the effects of herbivory would weaken from plants, to leaf-litter invertebrates, and to belowground microarthropod communities. First, we found that herbivory negatively impacted plant seedling and sapling abundance...... cascade from plants to the leaf-litter and soil arthropod communities with equal strength. While much recent research has focused on how specific traits of plants may mediate the effects of herbivory on associated species, our results suggest that indirect effects of herbivory might influence many...... and performance, reduced the abundance of ants and the taxonomic richness of arthropods in the litter layer and reduced the richness of soil microarthropod communities. Second, in contrast to our hypothesis, the magnitude of effect size did not vary among trophic levels, indicating that effects of deer herbivory...

  20. Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection

    DEFF Research Database (Denmark)

    Hughes, David P; Andersen, Sandra B; Hywel-Jones, Nigel L

    2011-01-01

    Parasites that manipulate host behavior can provide prominent examples of extended phenotypes: parasite genomes controlling host behavior. Here we focus on one of the most dramatic examples of behavioral manipulation, the death grip of ants infected by Ophiocordyceps fungi. We studied...... leaves ca. 25 cm above the soil surface where conditions for parasite development are optimal. Here we address whether the sequence of ant behaviors leading to the final death grip can also be interpreted as parasite adaptations and describe some of the morphological changes inside the heads of infected...... the interaction between O. unilateralis s.l. and its host ant Camponotus leonardi in a Thai rainforest, where infected ants descend from their canopy nests down to understory vegetation to bite into abaxial leaf veins before dying. Host mortality is concentrated in patches (graveyards) where ants die on sapling...

  1. A study on effects of knowledge management on organizational entrepreneurship: A case study of educational system

    Directory of Open Access Journals (Sweden)

    Naser Azad

    2012-09-01

    Full Text Available Knowledge management plays an important role in business development specially in educational system. The proposed study designs and distributes a questionnaire among experts who are involved in education systems in province of Tehran, Iran. The population of this survey includes 1680 people who are enrolled in administration levels of this province and using a simple sapling technique is calculated as 313. The questionnaire consists of 30 questions in Likert scale and there are six categories for the proposed study of this paper including the concept of knowledge, management, knowledge tools, knowledge measurement, change management, knowledge content. We have used LISREL software package to find the relationship between entrepreneurship and knowledge management components. Based on the results of this survey, knowledge content is number one priority followed by knowledge tools and concept of knowledge. The other factors including management, knowledge measurement and change management are in lower levels of importance.

  2. Uptake, Translocation, Metabolism, and Distribution of Glyphosate in Nontarget Tea Plant (Camellia sinensis L.).

    Science.gov (United States)

    Tong, Mengmeng; Gao, Wanjun; Jiao, Weiting; Zhou, Jie; Li, Yeyun; He, Lili; Hou, Ruyan

    2017-09-06

    The uptake, translocation, metabolism, and distribution behavior of glyphosate in nontarget tea plant were investigated. The negative effects appeared to grown tea saplings when the nutrient solution contained glyphosate above 200 mg L -1 . Glyphosate was highest in the roots of the tea plant, where it was also metabolized to aminomethyl phosphonic acid (AMPA). The glyphosate and AMPA in the roots were transported through the xylem or phloem to the stems and leaves. The amount of AMPA in the entire tea plant was less than 6.0% of the amount of glyphosate. The glyphosate level in fresh tea shoots was less than that in mature leaves at each day. These results indicated that free glyphosate in the soil can be continuously absorbed by, metabolized in, and transported from the roots of the tea tree into edible leaves, and therefore, free glyphosate residues in the soil should be controlled to produce teas free of glyphosate.

  3. A short life cycle of introduced Carex vulpina L. in the Donetsk Botanical Garden

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    Pavlova Marina Alexandrovna

    2015-12-01

    Full Text Available Basing on the study of a short life cycle in introduced ornamental Carex vulpina L. in the Donetsk Botanical Garden, we have revealed and described five main stages of ontogeny (plantlet, juvenile, immature, virginal, young generative and determined their time limits. It was found out that pregenerative period in this species lasts only for one growing season. This fact may be preconditioned by optimal for sapling development conditions (edaphic ones and agricultural methods. This study allowed us to formulate the following specific traits of a short life cycle in C. vulpina: a prolonged seed germination period, a long lasting relationship between a plant and its seed, an accelerated pregenerative period of ontogeny. Based on these data we suggest seed reproduction of this introduced species to be the best way to get a number of high grade planting material yet in the second year after sowing, which has implications for landscaping in our region.

  4. Genetic structure and mating system of Euterpe edulis Mart. Populations: a comparative analysis using microsatellite and allozyme markers.

    Science.gov (United States)

    Conte, Rudimar; Sedrez dos Reis, Mauricio; Mantovani, Adelar; Vencovsky, Roland

    2008-01-01

    A comparative study between microsatellite and allozyme markers was conducted on the genetic structure and mating system in natural populations of Euterpe edulis Mart. Three cohorts, including seedlings, saplings, and adults, were examined in 4 populations using 10 allozyme loci and 10 microsatellite loci. As expected, microsatellite markers had a much higher degree of polymorphism than allozymes, but estimates of multilocus outcrossing rate ( = 1.00), as well as estimates of genetic structure (F(IS), G(ST)), were similar for the 2 sets of markers. Estimates of R(ST), for microsatellites, were higher than those of G(ST), but results of both statistics revealed a close agreement for the genetic structure of the species. This study provides support for the important conclusion that allozymes are still useful and reliable markers to estimate population genetic parameters. Effects of sample size on estimates from hypervariable loci are also discussed in this paper.

  5. Characterization of Micronutrient Deficiency in Australian Red Cedar (Toona ciliata M. Roem var. australis

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    Bruno da Silva Moretti

    2012-01-01

    Full Text Available The Australian Red Cedar presents a great exploitation potential in Brazil, but works about the nutrient requirements and deficiency characterization in that species are still scarce. The objectives of this work were evaluating the effects of the omission of micronutrients and characterizing the nutrient deficiency symptoms in Australian Red Cedar saplings. The experiment was conducted in a greenhouse for a 90-day period. Australian Red Cedar cuttings were cultivated in pots with a nutrient solution under the missing element technique. The omission of the micronutrients B, Cu, Fe, Mn, and Zn affect negatively the height, diameter, and dry matter yield of the Australian Red Cedar plants. The micronutrient which affected the relative growth of the plants the most was B. Australian Red Cedar plants deficient in micronutrients present several visual symptoms characteristic of the metabolism disorders. The perception of the deficiencies through the visual diagnosis can be useful in the nutrient management of the culture of the Australian Red Cedar.

  6. Diversity and composition of understory vegetation in the tropical seasonal rain forest of Xishuangbanna, SW China

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    Lü Xiao-Tao

    2011-03-01

    Full Text Available Tropical forests vegetation and community research have tended to focus on the tree component, and limited attention has been paid to understory vegetation. Species diversity and composition of the understory of tropical seasonal rain forest were inventoried in a 625m² area (for sapling layer and a 100m² area (for herb/seedling layer in three 1ha plots. We found 3068 individuals belonging to 309 species, 192 genera and 89 families. The most important family as determined by the Family Importance Value (FIV was Rubiaceae in both sapling and herb/seedling layers. In terms of Importance Value Index (IVI, the shrub Mycetia gracilis (Rubiaceae was the most important species in the sapling layer and the pteridophyte Selaginella delicatula (Selaginellaceae was the most ecological significant species in the herb/seedling layer. Much more vascular plant species were registered in the understory than in the tree layer totaled among the three plots. The species diversity did not differ significantly among the tree layer, sapling layer and herb/seedling layer. Given that we still know little about the understory plant community for growth forms other than trees, the results from the present study indicate that more attention should be paid to the understory vegetation during the decision-making process for biodiversity conservation in the tropical forests. Rev. Biol. Trop. 59 (1: 455-463. Epub 2011 March 01.La investigación de la vegetación y las comunidades presentes en bosques tropicales han tendido a centrarse en el componente arbóreo, y se ha prestado poca atención a la vegetación del sotobosque. La diversidad de especies y la composición del sotobosque de los bosques tropicales estacionales fueron inventariados en un área de 625m² (identificación de árboles jóvenes y un área de 100 m² (capa de plántulas/hierbas en tres parcelas de 1 ha. Hemos encontrado 3 068 individuos pertenecientes a 309 especies, 192 géneros y 89 familias. La

  7. Impact of fog-drip versus fog immersion on leaf-level function of Bishop pines

    Science.gov (United States)

    Baguskas, S. A.; Still, C. J.

    2013-12-01

    Fog-water is known to be an important water source to plants in coastal, Mediterranean climates because it augments plant available water several months after the last winter rain, when conditions are otherwise warm and dry. While fog-drip to the soil surface is the most obvious contribution of fog to the water budget of an ecosystem, recent studies provide convincing evidence that foliar absorption of fog water is also possible. The focus of our research was to assess the relative importance of fog-drip and fog immersion on the photosynthetic capacity and gas exchange rates of a coastal pine species, Bishop pine (Pinus muricata, D.Don), a drought sensitive species restricted to the fogbelt of coastal California and offshore islands. We conducted a greenhouse study where we manipulated fog water inputs to potted Bishop pine saplings during a three-week dry-down period. Fifteen saplings were randomly assigned one of three treatments: 1) fog-drip and fog-immersion, 2) fog immersion alone, and 3) no fog water inputs. We artificially generated nighttime fog events using an ultrasonic device, which produces fog droplets. Given that the canopy architecture varied between saplings, we standardized the amount of fog-drip plants received by preventing direct fog drip from the canopy, and instead added the average amount of fog water that would have fallen from each canopy. To detect changes in soil moisture, we installed volumetric soil moisture probes in each pot at 2 and 10 cm depth. The plant response variables measured were photosynthetic capacity and maximum gas exchange rates of sapling trees. Our results show that plants which received both fog-drip and fog immersion sustained higher gas exchange rates and photosynthetic capacity through the dry-down period compared to trees in other treatment groups. Trees that received only fog immersion had lower rates of gas exchange and lower photosynthetic capacity relative to trees that received both fog-drip and fog immersion

  8. Surface Level Ozone and its Adverse Effects on Crops and Forests: A Need for an Interdisciplinary Understanding

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    Sagar V. Krupa

    2001-01-01

    Full Text Available Surface level ozone (O3 is clearly a global scale problem with regard to its adverse effects on crops, forests and native, terrestrial plant ecosystems. Photochemists and meteorologists are continuing to define the chemistry and physics of the prevalence of O3 at the ground level. Similarly, plant scientists in the U.S. and Europe have examined the effects of O3 on crops and tree seedlings or saplings through large-scale studies. Examples include the U.S. National Crop Loss Assessment Network (NCLAN, the U.S. EPA’s (Environmental Protection Agency’s San Bernardino National Forest Photochemical Oxidant Study, European Open-top Chambers Programme (EOTCP, and several ongoing EU (European Union projects. In addition, there have been studies on mature tree responses through field measurements and by simulation modeling.

  9. Psidium guajava as a bioaccumulator of nickel around an oil refinery, southern Brazil.

    Science.gov (United States)

    Trindade Perry, Carolina; Divan, Armando Molina; Raya Rodriguez, Maria Teresa; Lúcia Atz, Vera

    2010-05-01

    To evaluate the potential of Psidium guajava as a biological accumulator of air pollutants, saplings were exposed at nine sites receiving atmospheric emissions from an oil refinery (five within, four outside the industrial area) and another reference site located at the Federal University of Rio Grande do Sul, 27 km from the refinery. Exposures lasted about 3 months each, coincided with the seasons, and totaled five exposures between 2005 and 2006. The following parameters were evaluated: dry weight of leaves, stems, and roots, leaf area, rate of relative height increase, Ni and S contents, maximum assimilation rate, and carboxylation efficiency invivo. P. guajava was found to be an efficient accumulator of Ni, since highly significant differences were observed (Pguajava is a good bioaccumulator for Ni. Copyright 2009 Elsevier Inc. All rights reserved.

  10. Flooding and forest succession in a modified stretch along the upper Mississippi River

    Science.gov (United States)

    Yin, Yao

    1998-01-01

    This research examines the effect of a rare flood on floodplain forest regeneration in a 102-km stretch of the Mississippi River beginning 21 km above the mouth of the Ohio River. The river has been restricted by levees and navigation structures and subjected to sediment dredging to maintain a stable navigation channel. Because the bank erosion-accretion process has been slowed or eliminated, cottonwood (Populus spp.) and willow (Salix spp.) communities regenerate poorly in the modified river environment. An unusually large flood in 1993 destroyed the entire ground vegetation layer, killing 77.2% of the saplings and 32.2% of the trees. The flood created an alternative mechanism for cottonwood and willow to regenerate under canopy openings, enabling the community type composition of the present-day forest to be sustained for the next 50 years. Over time, however, the forest will likely exhibit considerable compositional fluctuation.

  11. Patterns of diversity and regeneration in unmanaged moist deciduous forests in response to disturbance in Shiwalik Himalayas, India

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    Mukesh Kumar Gautam

    2016-06-01

    Full Text Available We studied vegetation attributes in Indian tropical moist deciduous unmanaged forests to determine the influence of forest disturbances on them. We enumerated 89 species: 72 under moderate disturbance and 54 under least disturbance. The data from 3399 stems [>5 cm diameter at breast height (dbh] decreased linearly along the disturbance gradient. The basal area was largest in least disturbed forests (61 m2/ha and smallest in intensely disturbed forest (41 m2/ha. Under least and moderate disturbance, tree density-diameter distribution had negative exponential curves, whereas highly disturbed forests had unimodal-shaped curves where a few trees 5–10 cm and >50 cm in diameter were recorded. Most tree and shrub layer species under heavy and intense disturbance had impaired regeneration. Moderate disturbance intensity thus apparently benefits species diversity, stand density, and regeneration. Decline in seedlings and saplings, especially tree species, threaten forest regeneration and the maintenance of species diversity of unmanaged tropical forests.

  12. The effects of a simulated acid precipitation on leaf litter quality and the growth of a detritivore in a buffered lotic system.

    Science.gov (United States)

    Garden, A; Davies, R W

    1988-01-01

    The effects of a simulated acid rain on leaf litter quality and the growth of a detritivore in a buffered lotic system were investigated. Exposure of Populus balsamifera L. saplings to a simulated acid precipitation prior to leaf abscission resulted in significant decreases in foliar nitrogen content and increases in carbon: nitrogen ratios. During decomposition of the leaf litter in a buffered lotic system, microbial activity was significantly reduced. Growth of Tipula commiscibilis Diane (Diptera: Tipulidae) larvae decreased significantly when fed conditioned leaves exposed to a simulated acid precipitation prior to abscission. Reductions in detritivore growth were correlated with lower potential quality of the leaf litter resulting from increased carbon: nitrogen ratios and reduced levels of microbial activity. Thus, even in well buffered freshwater ecosystems, acid precipitation can have significant indirect effects on microbial activity and macroinvertebrate growth.

  13. QELBY®-Induced Enhancement of Exclusion Zone Buildup and Seed Germination

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    Abha Sharma

    2017-01-01

    Full Text Available A hydrophilic powder, QELBY, from the feldspar family of clay minerals was investigated for its ability to form structured or exclusion-zone (EZ water. We demonstrated microsphere-free zones around different fractions of the QELBY powder or its hydrated pellet. Averaging approximately 100 μm, these zones grew to a size similar to that formed in the vicinity of the Nafion standard. In the case of silica (control, only occasional microsphere-free zones of about 70 μm were found. Further, studies to investigate QELBY’s energizing effect on germination and early sapling growth in brown chickpea seeds showed at least a 2-3-fold increase in root length and/or formation of shoots. This was seen in seeds bathed in QELBY supernatants or surrounded by QELBY powder outside the vials containing the seeds. This indirect effect was observed whether the QELBY was dry or hydrated.

  14. Lowland-Edge Vegetation on Habitat of Proboscis Monkey (Nasalis larvatus in Rubber Forest of Tabalong District, South Kalimantan

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    MOHAMMAD BISMARK

    2005-01-01

    Full Text Available The proboscis monkey (Nasalis larvatus frequently visits certain lowland (baruh and never visits other, although both lowlands are inundated during rainy season or even have no water during the dry season. Data on seedling, sapling, pole, and tree of two former lowlands and of two latter ones were collected. Important value indexes were compared based on Renkonen similarity index. Treatments on vegetation were qualitatively recorded. The former lowlands had more diverse vegetation and higher security level than the latter had. Food sources, such as Hevea brasiliensis, Syzygium stapfiana, Vitex pubescens, Elaeocarpus stipularis, and Artocarpus teysmanii were available and more abundant on the former lowlands which were poorly cared. However, such condition could change anytime, because all lowlands include in the cultivated area.

  15. Patterns of woody plant invasion in an Argentinean coastal grassland

    Science.gov (United States)

    Alberio, Constanza; Comparatore, Viviana

    2014-01-01

    Coastal dune grasslands are fragile ecosystems that have historically been subjected to various types of uses and human activities. In Buenos Aires Province (Argentina), these areas are frequently afforested for urban and touristic development. The introduction and subsequent spread of exotic tree species is one of the main threats to conservation of natural grasslands as invasive trees strongly transform their structure and composition. The aim of this study was to identify patterns of woody plant invasion comparing plant communities and environmental variables between invaded and non-invaded areas surrounding the coastal village of Mar Azul, Argentina. Coastal grasslands in this area are being invaded by Populus alba (white poplar) and Acacia longifolia (coast wattle). The height of the saplings and the richness of the accompanying vegetation were evaluated in relation to the distance from the edge of the mature tree patches. Also, the cover, richness and diversity of all species in the invaded and non-invaded areas were measured, as well as soil pH, temperature and particle size. Negative correlations were found between the height of the saplings and distance to mature tree patches in all areas. The richness of the accompanying vegetation was negatively and positively correlated with the distance from the poplar and acacia area, respectively. The most abundant native species was Cortaderia selloana. Less cover, richness and diversity of native plant species and greater soil particle size were found in invaded areas, where the proportion of bare soil was higher. Also, a higher proportion of leaf litter in the invaded areas was registered. The results emphasize the invasive capacity of P. alba and A. longifolia advancing on the native communities and reducing their richness. Knowledge of the impact of invasive woody plants in coastal grasslands is important to design active management strategies for conservation purposes.

  16. A Demographic Approach to Evaluating Tree Population Sustainability

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    Corey R. Halpin

    2017-02-01

    Full Text Available Quantitative criteria for assessing demographic sustainability of tree populations would be useful in forest conservation, as climate change and a growing complex of invasive pests are likely to drive forests outside their historic range of variability. In this paper, we used CANOPY, a spatially explicit, individual‐tree model, to examine the effects of initial size distributions on sustainability of tree populations for 70 northern hardwood stands under current environmental conditions. A demographic sustainability index was calculated as the ratio of future simulated basal area to current basal area, given current demographic structure and density‐dependent demographic equations. Only steeply descending size distributions were indicated to be moderately or highly sustainable (final basal area/initial basal area ≥0.7 over several tree generations. Five of the six principal species had demographic sustainability index values of <0.6 in 40%–84% of the stands. However, at a small landscape scale, nearly all species had mean index values >1. Simulation experiments suggested that a minimum sapling density of 300 per hectare was required to sustain the initial basal area, but further increases in sapling density did not increase basal area because of coincident increases in mortality. A variable slope with high q‐ratios in small size classes was needed to maintain the existing overstory of mature and old‐growth stands. This analytical approach may be useful in identifying stands needing restoration treatments to maintain existing species composition in situations where forests are likely to have future recruitment limitations.

  17. Elevated air humidity affects hydraulic traits and tree size but not biomass allocation in young silver birches (Betula pendula

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    Arne eSellin

    2015-10-01

    Full Text Available As changes in air temperature, precipitation, and air humidity are expected in the coming decades, studies on the impact of these environmental shifts on plant growth and functioning are of major importance. Greatly understudied aspects of climate change include consequences of increasing air humidity on forest ecosystems, predicted for high latitudes. The main objective of this study was to find a link between hydraulic acclimation and shifts in trees’ resource allocation in silver birch (Betula pendula Roth in response to elevated air relative humidity (RH. A second question was whether the changes in hydraulic architecture depend on tree size. Two years of application of increased RH decreased the biomass accumulation in birch saplings, but the biomass partitioning among aboveground parts (leaves, branches, and stems remained unaffected. Increased stem Huber values (xylem cross-sectional area to leaf area ratio observed in trees under elevated RH did not entail changes in the ratio of non-photosynthetic to photosynthetic tissues. The reduction of stem-wood density is attributable to diminished mechanical load imposed on the stem, since humidified trees had relatively shorter crowns. Growing under higher RH caused hydraulic conductance of the root system (KR to increase, while KR (expressed per unit leaf area decreased and leaf hydraulic conductance increased with tree size. Saplings of silver birch acclimate to increasing air humidity by adjusting plant morphology (live crown length, slenderness, specific leaf area, and fine-root traits and wood density rather than biomass distribution among aboveground organs. The treatment had a significant effect on several hydraulic properties of the trees, while the shifts were largely associated with changes in tree size but not in biomass allocation.

  18. The response of Picea crassifolia forest to climate warming

    Science.gov (United States)

    He, Zhibin; Du, Jun; Yang, Junjun; Chen, Longfei; Zhu, Xi

    2014-05-01

    Picea crassifolia forest, an endemic genus mainly distributing in the Qilian Mountain of Northwest China, is very sensitive to climate warming. In the present study, the response of treeline, phenological period, and sap flow of P. crassifolia forest to climate warming were analyzed though a set of observations and experiments. The result showed: (1) During the past 50 years, the temperature had raised at a mean rate of 0.29° C per decade in this region, especially since 1980s (had increased by a total of more than 1.25° C), obviously higher than increment degree IPCC reported. This resulted in the increase of tree recruitment which was significantly positively correlated with the mean growing season temperature and with the mean minimum temperature in June and in winter. Treeline elevation shifted upward by 5.7 to 13.6 m from 1907 to 1957 and by 6.1 to 10.4 m after 1957. (2) By quantifying the canopy phenology events based on satellite-derived datasets (MODIS-NDVI) from 2001 to 2011, and investigating the correlation with climate factors, a conclusion had been drawn which revealed a 3.7 days/decade advance in the length of growing season. Our results suggested that temperature controlled treeline dynamics and phenological period more strongly than precipitation in the Qilian Mountains. (3) In the case of experimental warming (mean daily temperature was increased 0.83° C, mean daily maximum temperature was increased 4.7° C), the trend for the mass growth of P. crassifolia sapling presented a notable increase under conditions of warming, especially for tree height. The data of sap flow showed that warming facilitated the sap flow of sapling in the end of growing season, which indicated the temperature was a major restriction to sap flow rate, especially in the condition of lower temperature.

  19. Effects of invasive alien kahili ginger (Hedychium gardnerianum) on native plant species regeneration in a Hawaiian rainforest

    Science.gov (United States)

    Minden, V.; Jacobi, J.D.; Porembski, S.; Boehmer, H.J.

    2010-01-01

    Questions: Does the invasive alien Hedychium gardnerianum (1) replace native understory species, (2) suppress natural regeneration of native plant species, (3) increase the invasiveness of other non-native plants and (4) are native forests are able to recover after removal of H. gardnerianum. Location: A mature rainforest in Hawai'i Volcanoes National Park on the island of Hawai'i (about 1200 m. a.s.l.; precipitation approximately 2770mm yr-1). Study sites included natural plots without effects of alien plants, ginger plots with a H. gardnerianum-domimted herb layer and cleared plots treated with herbicide to remove alien plants. Methods: Counting mature trees, saplings and seedlings of native and alien plant species. Using nonparametric H-tests to compare impact of H. gardnerianum on the structure of different sites. Results: Results confirmed the hypothesis that H. gardnerianum has negative effects on natural forest dynamics. Lower numbers of native tree seedlings and saplings were found on ginger-dominated plots. Furthermore, H. gardnerianum did not show negative effects on the invasive alien tree species Psidium cattleianum. Conclusions: This study reveals that where dominance of H. gardnerianum persists, regeneration of the forest by native species will be inhibited. Furthermore, these areas might experience invasion by P. cattleianum, resulting in displacement of native canopy species in the future, leading to a change in forest structure and loss of other species dependent on natural rainforest, such as endemic birds. However, if H. gardnerianum is removed the native Hawaiian forest is likely to regenerate and regain its natural structure. ?? 2009 International Association for Vegetation Science.

  20. Uncertainty in Forest Net Present Value Estimations

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    Ilona Pietilä

    2010-09-01

    Full Text Available Uncertainty related to inventory data, growth models and timber price fluctuation was investigated in the assessment of forest property net present value (NPV. The degree of uncertainty associated with inventory data was obtained from previous area-based airborne laser scanning (ALS inventory studies. The study was performed, applying the Monte Carlo simulation, using stand-level growth and yield projection models and three alternative rates of interest (3, 4 and 5%. Timber price fluctuation was portrayed with geometric mean-reverting (GMR price models. The analysis was conducted for four alternative forest properties having varying compartment structures: (A a property having an even development class distribution, (B sapling stands, (C young thinning stands, and (D mature stands. Simulations resulted in predicted yield value (predicted NPV distributions at both stand and property levels. Our results showed that ALS inventory errors were the most prominent source of uncertainty, leading to a 5.1–7.5% relative deviation of property-level NPV when an interest rate of 3% was applied. Interestingly, ALS inventory led to significant biases at the property level, ranging from 8.9% to 14.1% (3% interest rate. ALS inventory-based bias was the most significant in mature stand properties. Errors related to the growth predictions led to a relative standard deviation in NPV, varying from 1.5% to 4.1%. Growth model-related uncertainty was most significant in sapling stand properties. Timber price fluctuation caused the relative standard deviations ranged from 3.4% to 6.4% (3% interest rate. The combined relative variation caused by inventory errors, growth model errors and timber price fluctuation varied, depending on the property type and applied rates of interest, from 6.4% to 12.6%. By applying the methodology described here, one may take into account the effects of various uncertainty factors in the prediction of forest yield value and to supply the

  1. 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.

  2. Resistance to wildfire and early regeneration in natural broadleaved forest and pine plantation

    Science.gov (United States)

    Proença, Vânia; Pereira, Henrique M.; Vicente, Luís

    2010-11-01

    The response of an ecosystem to disturbance reflects its stability, which is determined by two components: resistance and resilience. We addressed both components in a study of early post-fire response of natural broadleaved forest ( Quercus robur, Ilex aquifolium) and pine plantation ( Pinus pinaster, Pinus sylvestris) to a wildfire that burned over 6000 ha in NW Portugal. Fire resistance was assessed from fire severity, tree mortality and sapling persistence. Understory fire resistance was similar between forests: fire severity at the surface level was moderate to low, and sapling persistence was low. At the canopy level, fire severity was generally low in broadleaved forest but heterogeneous in pine forest, and mean tree mortality was significantly higher in pine forest. Forest resilience was assessed by the comparison of the understory composition, species diversity and seedling abundance in unburned and burned plots in each forest type. Unburned broadleaved communities were dominated by perennial herbs (e.g., Arrhenatherum elatius) and woody species (e.g., Hedera hibernica, Erica arborea), all able to regenerate vegetatively. Unburned pine communities presented a higher abundance of shrubs, and most dominant species relied on post-fire seeding, with some species also being able to regenerate vegetatively (e.g., Ulex minor, Daboecia cantabrica). There were no differences in diversity measures in broadleaved forest, but burned communities in pine forest shared less species and were less rich and diverse than unburned communities. Seedling abundance was similar in burned and unburned plots in both forests. The slower reestablishment of understory pine communities is probably explained by the slower recovery rate of dominant species. These findings are ecologically relevant: the higher resistance and resilience of native broadleaved forest implies a higher stability in the maintenance of forest processes and the delivery of ecosystem services.

  3. Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

    Science.gov (United States)

    Lang, K.D.; Schulte, L.A.; Guntenspergen, G.R.

    2009-01-01

    Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow

  4. Short-Term Effects of Reduced-Impact Logging on Copaifera spp. (Fabaceae Regeneration in Eastern Amazon

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    Carine Klauberg

    2017-07-01

    Full Text Available Timber management directly influences the population dynamics of tree species, like Copaifera spp. (copaíba, which provide oil-resin with ecological and economic importance. The aim of this study was to evaluate the structure and population dynamics of Copaifera in unmanaged and managed stands by reduced-impact logging (RIL in eastern Amazon in Pará state, Brazil. Based on a stem map of the study area, 40 Copaifera trees were randomly selected, where an equal number of trees were selected in managed and unmanaged stands. A transect of 10 × 100 m was centered at each tree (50 m each side to assess Copaifera regeneration. Transects were subdivided into ten plots, of which six were systematically chosen to assess the height, diameter and number of Copaifera seedlings and saplings. The field assessment occurred in 2011 and 2013. To estimate the amount of sunlight transmitted to the forest floor, we computed canopy cover from airborne LiDAR data. According to the results, the abundance of Copaifera seedlings/saplings was higher in managed than unmanaged stands. About 5% of Copaifera regeneration was found between 45–50 m from the Copaifera tree while ~73% of regeneration was concentrated within a 10 m radius of the Copaifera tree. We verified that the diameter distribution of Copaifera regeneration was not a negative exponential distribution, as is typical of most tree species in natural forest. Rather, the Copaifera regeneration had a spatially aggregated distribution. In this short-term analysis, the impact of timber management is not negatively affecting the population structure or dynamics of Copaifera regeneration.

  5. Pollinator limitation and the effect of breeding systems on plant reproduction in forest fragments

    Science.gov (United States)

    Nayak, K. Geetha; Davidar, Priya

    2010-03-01

    Reproduction of plants in fragmented habitats may be limited because of lower diversity or abundance of pollinators, and/or variation in local plant density. We assessed natural fruit set and pollinator limitation in ten species of woody plants in natural and restored fragments in the Pondicherry region of southern India, to see whether breeding system of plants (self-compatible and self-incompatible) affected fruit set. We tested whether the number of flowering individuals in the fragments affected the fruit set and further examined the adult and sapling densities of self-compatible (SC) and self-incompatible (SI) species. We measured the natural level of fruit set and pollinator limitation (calculated as the difference in fruit set between hand cross-pollinated and naturally pollinated flowers). Our results demonstrate that there was a higher level of pollinator limitation and hence lower levels of natural fruit set in self-incompatible species as compared to self-compatible species. However, the hand cross-pollinated flowers in SC and SI species produced similar levels of fruit set, further indicating that lower fruit set was due to pollinator limitation and not due to lack of cross-compatible individuals in the fragments. There was no significant relation between number of flowering individuals and the levels of natural fruit set, except for two species Derris ovalifolia, Ixora pavetta. In these species the natural fruit set decreased with increasing population size, again indicating pollinator limitation. The adult and sapling densities in self-compatible species were significantly higher than in self-incompatible species. These findings indicate that the low reproductive output in self-incompatible species may eventually lead to lower population sizes. Restoration of pollinator services along with plant species in fragmented habitats is important for the long-term conservation of biodiversity.

  6. The effects of herbivory by a mega- and mesoherbivore on tree recruitment in sand forest, South Africa.

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    D D Georgette Lagendijk

    Full Text Available Herbivory by megaherbivores on woody vegetation in general is well documented; however studies focusing on the individual browsing effects of both mega- and mesoherbivore species on recruitment are scarce. We determined these effects for elephant Loxodonta africana and nyala Tragelaphus angasii in the critically endangered Sand Forest, which is restricted to east southern Africa, and is conserved mainly in small reserves with high herbivore densities. Replicated experimental treatments (400 m(2 in a single forest patch were used to exclude elephant, or both elephant and nyala. In each treatment, all woody individuals were identified to species and number of stems, diameter and height were recorded. Results of changes after two years are presented. Individual tree and stem densities had increased in absence of nyala and elephant. Seedling recruitment (based on height and diameter was inhibited by nyala, and by elephant and nyala in combination, thereby preventing recruitment into the sapling stage. Neither nyala or elephant significantly reduced sapling densities. Excluding both elephant and nyala in combination enhanced recruitment of woody species, as seedling densities increased, indicating that forest regeneration is impacted by both mega- and mesoherbivores. The Sand Forest tree community approached an inverse J-shaped curve, with the highest abundance in the smaller size classes. However, the larger characteristic tree species in particular, such as Newtonia hildebrandtii, were missing cohorts in the middle size classes. When setting management goals to conserve habitats of key importance, conservation management plans need to consider the total herbivore assemblage present and the resulting browsing effects on vegetation. Especially in Africa, where the broadest suite of megaherbivores still persists, and which is currently dealing with the 'elephant problem', the individual effects of different herbivore species on recruitment and

  7. Resuspension of small particles from tree surfaces

    Science.gov (United States)

    Ould-Dada, Zitouni; Baghini, Nasser M.

    A detailed study of resuspension of 1.85 μm MMAD silica particles from five horizontal layers within a small scale spruce canopy was carried out in a wind tunnel in which saplings were exposed to a constant free stream wind speed of 5 m s -1. This provided quantitative estimates of the potential for a tree canopy contaminated with an aerosol deposit to provide (i) an airborne inhalation hazard within the forest environment and (ii) a secondary source of airborne contamination after an initial deposition event. Resuspension occurred with a flux of 1.05×10 -7 g m -2 s -1 from spruce saplings initially contaminated at a level of 4.1×10 -2 g m -2. An average resuspension rate ( Λ) of 4.88×10 -7 s -1 was obtained for the canopy as a whole. Values of Λ were significantly different (ANOVA, p<0.001) between canopy layers and Λ was markedly greater at the top of the canopy than lower down although there was a slight increase in Λ at the base of the canopy. The resuspended silica particles deposited onto the soil surface at an average rate of about 5.3×10 -8 μg cm -2 s -1. It is concluded that resuspension under wind velocities similar to that used in the reported experiments is likely to pose a relatively small inhalation hazard to humans and a relatively minor source of secondary contamination of adjacent areas. Furthermore, resuspension rates are likely to diminish rapidly with time. The results are discussed in relation to the growing interest in the tree planting schemes in urban areas to reduce the impacts of air pollution.

  8. Impact of warming and drought on carbon balance related to wood formation in black spruce.

    Science.gov (United States)

    Deslauriers, Annie; Beaulieu, Marilène; Balducci, Lorena; Giovannelli, Alessio; Gagnon, Michel J; Rossi, Sergio

    2014-08-01

    Wood formation in trees represents a carbon sink that can be modified in the case of stress. The way carbon metabolism constrains growth during stress periods (high temperature and water deficit) is now under debate. In this study, the amounts of non-structural carbohydrates (NSCs) for xylogenesis in black spruce, Picea mariana, saplings were assessed under high temperature and drought in order to determine the role of sugar mobilization for osmotic purposes and its consequences for secondary growth. Four-year-old saplings of black spruce in a greenhouse were subjected to different thermal conditions with respect to the outside air temperature (T0) in 2010 (2 and 5 °C higher than T0) and 2011 (6 °C warmer than T0 during the day or night) with a dry period of about 1 month in June of each year. Wood formation together with starch, NSCs and leaf parameters (water potential and photosynthesis) were monitored from May to September. With the exception of raffinose, the amounts of soluble sugars were not modified in the cambium even if gas exchange and photosynthesis were greatly reduced during drought. Raffinose increased more than pinitol under a pre-dawn water potential of less than -1 Mpa, presumably because this compound is better suited than polyol for replacing water and capturing free radicals, and its degradation into simple sugar is easier. Warming decreased the starch storage in the xylem as well the available hexose pool in the cambium and the xylem, probably because of an increase in respiration. Radial stem growth was reduced during drought due to the mobilization of NSCs for osmotic purposes and due to the lack of cell turgor. Thus plant water status during wood formation can influence the NSCs available for growth in the cambium and xylem. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Modeling of bud break of Scots pine in northern Finland in 1908–2014

    Science.gov (United States)

    Salminen, Hannu; Jalkanen, Risto

    2015-01-01

    Bud break and height-growth of Scots pine (Pinus sylvestris L.) in the northern boreal zone in Lapland, Finland, was followed through the entire growing seasons in the periods 2001–2003 and 2008–2010 in sapling stands in two different locations in northern Finland set some 250 km apart along a latitudinal transect. Field measurements continued at the southern site also in 2011–2013. Air temperature was recorded hourly at the sites. A simple optimization algorithm (GA) was used to adjust parameters of the models predicting the timing of bud break of Scots pine in order to minimize the difference between observed and predicted dates. The models giving the best performance and century-long daily temperatures were used to reconstruct bud-break time series. The temperature observations were recorded for the period 1908–2014 in Sodankylä, which is located in-between the sapling stands in the north–south direction and for the period 1877–2014 in Karasjok, which is in Norway about 145 km north–west from the northernmost stand of this study. On average buds began to extend in the beginning of May in the southernmost stand and in mid-May in the northernmost stands, and the variation between years was in the range of 3 weeks. A simple day-length-triggered (fixed date) model predicted most accurately the date of bud break; root mean square error (RMSE) was 2 and 4 days in the northern and southern site, respectively. The reconstructed bud-break series indicated that based on temperature observations from Sodankylä, growth onset of Scots pine has clearly advanced since the 1960s, though it currently matches that of the early 1920s and early 1950s. The temperature record from Karasjok indicated a similar variation, though there was a weak linear trend advancing bud break by about 3–4 days over a 100-year period. PMID:25798141

  10. Modeling of bud break of Scots pine in northern Finland in 1908-2014.

    Science.gov (United States)

    Salminen, Hannu; Jalkanen, Risto

    2015-01-01

    Bud break and height-growth of Scots pine (Pinus sylvestris L.) in the northern boreal zone in Lapland, Finland, was followed through the entire growing seasons in the periods 2001-2003 and 2008-2010 in sapling stands in two different locations in northern Finland set some 250 km apart along a latitudinal transect. Field measurements continued at the southern site also in 2011-2013. Air temperature was recorded hourly at the sites. A simple optimization algorithm (GA) was used to adjust parameters of the models predicting the timing of bud break of Scots pine in order to minimize the difference between observed and predicted dates. The models giving the best performance and century-long daily temperatures were used to reconstruct bud-break time series. The temperature observations were recorded for the period 1908-2014 in Sodankylä, which is located in-between the sapling stands in the north-south direction and for the period 1877-2014 in Karasjok, which is in Norway about 145 km north-west from the northernmost stand of this study. On average buds began to extend in the beginning of May in the southernmost stand and in mid-May in the northernmost stands, and the variation between years was in the range of 3 weeks. A simple day-length-triggered (fixed date) model predicted most accurately the date of bud break; root mean square error (RMSE) was 2 and 4 days in the northern and southern site, respectively. The reconstructed bud-break series indicated that based on temperature observations from Sodankylä, growth onset of Scots pine has clearly advanced since the 1960s, though it currently matches that of the early 1920s and early 1950s. The temperature record from Karasjok indicated a similar variation, though there was a weak linear trend advancing bud break by about 3-4 days over a 100-year period.

  11. Effectiveness of fencing and hunting to control Lama guanicoe browsing damage: Implications for Nothofagus pumilio regeneration in harvested forests.

    Science.gov (United States)

    Martínez Pastur, Guillermo; Soler, Rosina; Ivancich, Horacio; Lencinas, María V; Bahamonde, Héctor; Peri, Pablo L

    2016-03-01

    Browsing damage by native ungulates is often to be considered one of the reasons of regeneration failure in Nothofagus pumilio silvicultural systems. Fencing and hunting in forests at regeneration phase have been proposed to mitigate browsing effects. This study aims to determine effectiveness of these control methods in harvested forests, evaluating browsing damage over regeneration, as well as climate-related constraints (freezing or desiccation). Forest structure and regeneration plots were established in two exclosures against native ungulates (Lama guanicoe) by wire fences in the Chilean portion of Tierra del Fuego island, where tree regeneration density, growth, abiotic damage and quality (multi-stems and base/stem deformation) were assessed. Exclosures did not influence regeneration density (at the initial stage with 1.3 m high). However, sapling height at 10-years old was significantly lower outside (40-50 cm high) than inside exclosures (80-100 cm), and also increased their annual height growth, probably as a hunting effect. Likewise, quality was better inside exclosures. Alongside browsing, abiotic conditions negatively influenced sapling quality in the regeneration phase (20%-28% of all seedlings), but greatly to taller plants (as those from inside exclosure). This highlights the importance of considering climatic factors when analysing browsing effects. For best results, control of guanaco in recently harvested areas by fencing should be applied in combination with a reduction of guanaco density through continuous hunting. The benefits of mitigation actions (fencing and hunting) on regeneration growth may shorten the regeneration phase period in shelterwood cutting forests (30-50% less time), but incremental costs must be analysed in the framework of management planning by means of long-term studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. STRUKTUR KOMUNITAS, ZONASI DAN KEANEKARAGAMAN HAYATI VEGETASI MANGROVE DI SEGARA ANAKAN CILACAP

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    Endang Hilmi

    2015-11-01

    Full Text Available Mangrove ecosystem of Segara Anakan Cilacap has specific vegetation, function, and benefit. It was dominated by Rhizophora, Bruguiera, Avicennia and associate vegetation such as Nypa frutican. Stability of mangrove ecosystem can be seen by community structure, zonation and diversity of mangrove vegetation. This research aimed to analyze community structure, zonnation and diversity of mangrove vegetation in Segara Anakan Lagoon. This research used survey method with cluster sampling by stratified analysis. The Analyze of data used association analysis, zonation analysis, richnes index, and Shanon Wiener index. This Research showed that (1 Association index of seedling was dominated by index < 0.22 (lowest association with scored 46,67 % - 66.66 %, (2 Association index of sapling also was dominated by index < 0.22 (lowest association with scored 58,33% - 71.43 %, (3 Association index of tress also was dominated by index < 0.22 (lowest association with scored 67,27 % % (4 Overlaping indeks showed Aegiceras corniculatum has high overlap toward Nypa frutican (71 % (seedling stage and Rhizophora apiculata to Avicennia spp (0,49 (sapling stage. (5 Zonation of mangrove showed that Zone 1 as direct connecting zone with sea which were dominated by Avicennia marina and Avicennia oficinallis. Zone 2 as the middle zone which were dominated by Rhizophora mucronata, Rhizophora apiculata, and Ceriops tagal. Zone 3 as direct connecting zone with island which were dominated by Nypa fruticans, Acanthus ilicifolius, and Sonneratia casseolaris (6 diversity index between 0.48 – 1.83 (low – middle. Keywords : mangrove vegetation, acosiation index, zonation, community structure and diversity

  13. Growth and Nutrition of Eucalypt Rooted Cuttings Promoted by Ectomycorrhizal Fungi in Commercial Nurseries

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    Andrezza Mara Martins Gandini

    2015-12-01

    Full Text Available ABSTRACT Ectomycorrhizal fungi (EMF may improve the adaptation of eucalypts saplings to field conditions and allow more efficient fertilizer use. The effectiveness of EMF inoculum application in promoting fungal colonization, plant growth, nutrient uptake, and the quality of rooted cuttings was evaluated forEucalyptus urophylla under commercial nursery conditions. For inoculated treatments, fertilization of the sapling substrate was reduced by 50 %. The experiment was carried out in a completely randomized design in a 4 × 4 factorial arrangement, wherein the factors were inoculum application rates of 0 (control, 5, 10, and 15 gel beads of calcium alginate containing the vegetative mycelium of Amanita muscaria, Elaphomyces antracinus, Pisolithus microcarpus, andScleroderma areolatum, plus a non-inoculated treatment without fertilization reduction in the substrate (commercial. Ectomycorrhizal fungi increased plant growth and fungal colonization as well as N and K uptake evenly. The best plant growth and fungal colonization were observed for the highest application rate. The greatest growth and fungal colonization and contents of P, N, and K were observed at the 10-bead rate. Plant inoculation with Amanita muscaria, Elaphomyces anthracinus, and Scleroderma areolatum increased P concentrations and contents in a differential manner. The Dickson Quality Index was not affected by the type of fungi or by inoculum application rates. Eucalypt rooted cuttings inoculated with ectomycorrhizal fungi and under half the amount of commercial fertilization had P, N, and K concentrations and contents greater than or equal to those of commercial plants and have high enough quality to be transplanted after 90 days.

  14. TREES AND REGENERATION IN RUBBER AGROFORESTS AND OTHER FOREST-DERIVED VEGETATION IN JAMBI (SUMATRA, INDONESIA

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    Hesti L. Tata

    2008-06-01

    Full Text Available The rubber  agroforests  (RAF  of Indonesia provide  a dynamic interface  between natural  processes  of forest  regeneration and  human’s management   targeting  the harvesting  of latex  with  minimum investment  of time  and financial  resources.  The composition  and species richness  of higher  plants  across an intensification gradient from forest to monocultures of tree crops have been investigated  in six land use types (viz. secondary forest, RAF, rubber monoculture, oil palm plantation, cassava field and Imperata grassland  in Bungo,  Jambi  Province,  Indonesia.  We emphasize  comparison of four different  strata  (understory, seedling,  sapling  and tree of vegetation  between forest and RAF,  with  specific interest  in plant  dependence  on ectomycorrhiza fungi. Species richness  and species accumulation curves for seedling  and sapling  stages were similar  between forest and RAF,  but in the tree stratum  (trees > 10 cm dbh selective thinning by farmers was evident in a reduction  of species diversity and an increase in the proportion of trees with edible parts. Very few trees dependent on ectomycorrhiza fungi were encountered  in the RAF. However, the relative distribution of early and late successional species as evident from the wood density distribution showed no difference between RAF and forest.

  15. Keanekaragaman dan Pola Komunitas Hutan Mangrove di Andai Kabupaten Manokwari Analisis Vegetasi Hutan Rawa Gambut Pascakebakaran di Wilayah Desa Sebangau dan Desa Taruna Jaya

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    Onasius Pieter Matan

    2016-10-01

    . Nilai indeks keanekaragaman menunjukkan bahwa  nilai terendah terdapat pada releve 2 sedangkan nilai tertinggi ada pada releve 3.   Namun secara keseluruhan nilai indeks keanekaragaman sedang  untuk setiap  tingkatan  pertumbuhan pada semua releve.  Nilai tersebut menunjukkan bahwa  perkembangan ekosistem  pada hutan mangrove Andai tergolong sedang.   ABSTRACT In an effort to maintain the sustainability of mangrove forests, information about the potential  of  mangrove  resources  are  needed  as  basic  data  for  management  planning  and utilization of mangrove forests. This study aims to determine species composition, diversity and community patterns in mangrove forest, the Regency of Manokwari. Research area is divided into 2 parts by the river, where the first part consists of  6 releve and the second part 7 releve. In each releve plot observations made for the level of seedlings, saplings  and  trees.  The  data  recorded  includes  species,  number,  diameter,  height,  and environmental  parameters  data.  Data  were  analyzed  by  calculating  the  index  key  value, determine the pattern of community grouping with a 2-dimensional ordination methods, and calculate the value of diversity index. The results showed that the composition of species at the seedling level consists of 31  species  of  mangrove  (19  true  mangrove  species,  12  species  of  mangrove  follow-up. Saplings level consists of 29 species of mangrove (18 true mangrove species, 11 species of mangrove follow-up. Tree level consists of 30 species of mangrove (20 true mangrove species and 10 mangrove species follow-up. True mangrove cover 7 family. While mangrove follow-up includes 13 family. Dominance of mangrove seedlings at the level of Bruguiera parviflora (IVI = 481.71, at the saplings level Rhizophora apiculata dominated (IVI = 903.27 and at the tree level dominated by Rhizophora apiculata (IVI = 664.91. Community grouping pattern

  16. Mycorrhizal inoculation as a tool for sustainable bio-engineering measures in steep alpine environments? - Results of a three year field experiment

    Science.gov (United States)

    Bast, Alexander; Wilcke, Wolfgang; Lüscher, Peter; Graf, Frank; Gärtner, Holger

    2013-04-01

    Global warming is anticipated to result in an increase of heavy precipitation events. In vegetation-free, steep Alpine areas intense rain fall events have distinct influences on erosional processes on slopes. These processes and (shallow) mass movements are directly linked with torrential rain falls, and for this lead to high erosion rates in those regions, resulting in an increased natural and socio-economic damage potential. For restoring and managing erosion-prone sites, bioengineering measures as a tool for hazard prevention gain more importance. Due to the rough environmental conditions, and hence, reduced germination capability and sprout vigour, it is difficult to establish a dense cover of pioneer vegetation. Thus, the question is what can be done to give planted saplings within bioengineering projects maximum support, to develop their above- and belowground structures to promote slope stabilization. Green-house and laboratory experiments have shown that mycorrhizal inoculum has a positive impact on plant development and soil structure, e.g. the formation of (stable) aggregates within several months. Based on these promising results, we intended to apply mycorrhizal inoculation in a field-experiment. In May 2010, we established experimental plots at an erosion-prone talus slope (inclination: ~40 - 45 °; elevation 1220 - 1360 m a.s.l.), located in the Eastern Swiss Alps. The slope, consisting of moraine and denudation-derived substrate, shows high geomorphic activity (e.g. debris flows, rill erosion). Two slope areas, 10m wide and 32m long, were stabilized with 1200 plants each. Additionally, mycorrhiza inoculum (INOQ Forst, 40 ml/plant) was added to one of the two areas. Within the stabilized areas, a mixture of eight saplings was planted per running meter in 15 rows. The assortment included four saplings of green alder and two of purple willow, as well as one tree (maple, birch, ash) and shrub species (e.g. guelder rose, honeysuckle). Finally, both areas

  17. Regeneração de espécies arbóreas sob a influência de Merostachys multiramea Hack. (Poaceae em uma floresta subtropical Regeneration of tree species influenced by Merostachys multiramea Hack. (Poaceae in a subtropical forest

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    Suzana Cyrino dos Santos

    2012-03-01

    Full Text Available A ocorrência de bambúseas é comum em muitas fisionomias florestais, sendo que a elevada abundância destas espécies pode interagir com a regeneração de espécies arbóreas. Foi avaliada a regeneração de espécies arbóreas e de Merostachys multiramea Hack. em uma área de transição entre Floresta Ombrófila Mista e Floresta Estacional no Sul do Brasil e comparada a estrutura de regeneração da área entre dois e quatro anos após floração, frutificação e morte de M. multiramea. Foram alocadas 25 unidades amostrais de 100 m² dispostas de forma aleatória, onde foram amostrados todos os colmos vivos de M. multiramea e indivíduos regenerantes de espécies arbóreas > 30 cm de altura e com perímetro à altura do peito The occurrence of bamboo species is common in several forest physiognomies, and the high abundance of these species may affect the regeneration of other ones. We evaluated both tree species and Merostachys multiramea Hack. recruitment in a transition area between mixed Araucaria rain forest and seasonal semideciduous forests in southern Brazil. We compared the regeneration structure of the areas evaluated two and four years after flowering, fruiting and death of M. multiramea. We randomly distributed 25 100 m² sampling units, and surveyed all living culms of M. multiramea and tree saplings. We sampled 4,372 living bamboos and 2,918 tree saplings, belonging to 32 plant families and 75 species. Most species were classified as zoochorous and canopy light-demanding. On the other hand, plant abundance revealed a greater contribution of autochorous, understory and shade-tolerant trees. M. multiramea density was higher over the four years after the reproductive event (p<0.05, with taller culms (p<0.01, but with the same mean number of culms (p=0.46. A NPMANOVA revealed significant differences in composition and abundance between surveys, with higher similarity among samplings two years after the reproductive event of M

  18. Quantification and identification of lightning damage in tropical forests.

    Science.gov (United States)

    Yanoviak, Stephen P; Gora, Evan M; Burchfield, Jeffrey M; Bitzer, Phillip M; Detto, Matteo

    2017-07-01

    Accurate estimates of tree mortality are essential for the development of mechanistic forest dynamics models, and for estimating carbon storage and cycling. However, identifying agents of tree mortality is difficult and imprecise. Although lightning kills thousands of trees each year and is an important agent of mortality in some forests, the frequency and distribution of lightning-caused tree death remain unknown for most forests. Moreover, because all evidence regarding the effects of lightning on trees is necessarily anecdotal and post hoc, rigorous tests of hypotheses regarding the ecological effects of lightning are impossible. We developed a combined electronic sensor/camera-based system for the location and characterization of lightning strikes to the forest canopy in near real time and tested the system in the forest of Barro Colorado Island, Panama. Cameras mounted on towers provided continuous video recordings of the forest canopy that were analyzed to determine the locations of lightning strikes. We used a preliminary version of this system to record and locate 18 lightning strikes to the forest over a 3-year period. Data from field surveys of known lightning strike locations (obtained from the camera system) enabled us to develop a protocol for reliable, ground-based identification of suspected lightning damage to tropical trees. In all cases, lightning damage was relatively inconspicuous; it would have been overlooked by ground-based observers having no knowledge of the event. We identified three types of evidence that can be used to consistently identify lightning strike damage in tropical forests: (1) localized and directionally biased branch mortality associated with flashover among tree and sapling crowns, (2) mortality of lianas or saplings near lianas, and (3) scorched or wilting epiphytic and hemiepiphytic plants. The longitudinal trunk scars that are typical of lightning-damaged temperate trees were never observed in this study. Given the

  19. Does reduced precipitation trigger physiological and morphological drought adaptations in European beech (Fagus sylvatica L.)? Comparing provenances across a precipitation gradient.

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    Knutzen, Florian; Meier, Ina Christin; Leuschner, Christoph

    2015-09-01

    Global warming and associated decreases in summer rainfall may threaten tree vitality and forest productivity in many regions of the temperate zone in the future. One option for forestry to reduce the risk of failure is to plant genotypes which combine high productivity with drought tolerance. Growth experiments with provenances from different climates indicate that drought exposure can trigger adaptive drought responses in temperate trees, but it is not well known whether and to what extent regional precipitation reduction can increase the drought resistance of a species. We conducted a common garden growth experiment with five European beech (Fagus sylvatica L.) populations from a limited region with pronounced precipitation heterogeneity (816-544 mm year(-1)), where phylogenetically related provenances grew under small to large water deficits. We grew saplings of the five provenances at four soil moisture levels (dry to moist) and measured ∼30 morphological (leaf and root properties, root : shoot ratio), physiological (leaf water status parameters, leaf conductance) and growth-related traits (above- and belowground productivity) with the aim to examine provenance differences in the drought response of morphological and physiological traits and to relate the responsiveness to precipitation at origin. Physiological traits were more strongly influenced by provenance (one-third of the studied traits), while structural traits were primarily affected by water availability in the experiment (two-thirds of the traits). The modulus of leaf tissue elasticity ϵ reached much higher values late in summer in plants from moist origins resulting in more rapid turgor loss and a higher risk of hydraulic failure upon drought. While experimental water shortage affected the majority of morphological and productivity-related traits in the five provenances, most parameters related to leaf water status were insensitive to water shortage. Thus, plant morphology, and root

  20. Do the Golden-winged Warbler and Blue-winged Warbler Exhibit Species-specific Differences in their Breeding Habitat Use?

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    Laura L. Patton

    2010-12-01

    Full Text Available We compared habitat features of Golden-winged Warbler (Vermivora chrysoptera territories in the presence and absence of the Blue-winged Warbler (V. cyanoptera on reclaimed coal mines in southeastern Kentucky, USA. Our objective was to determine whether there are species specific differences in habitat that can be manipulated to encourage population persistence of the Golden-winged Warbler. When compared with Blue-winged Warblers, Golden-winged Warblers established territories at higher elevations and with greater percentages of grass and canopy cover. Mean territory size (minimum convex polygon was 1.3 ha (se = 0.1 for Golden-winged Warbler in absence of Blue-winged Warbler, 1.7 ha (se = 0.3 for Golden-winged Warbler coexisting with Blue-winged Warbler, and 2.1 ha (se = 0.3 for Blue-winged Warbler. Territory overlap occurred within and between species (18 of n = 73 territories, 24.7%. All Golden-winged and Blue-winged Warblers established territories that included an edge between reclaimed mine land and mature forest, as opposed to establishing territories in open grassland/shrubland habitat. The mean distance territories extended from a forest edge was 28.0 m (se = 3.8 for Golden-winged Warbler in absence of Blue-winged Warbler, 44.7 m (se = 5.7 for Golden-winged Warbler coexisting with Blue-winged Warbler, and 33.1 m (se = 6.1 for Blue-winged Warbler. Neither territory size nor distances to forest edges differed significantly between Golden-winged Warbler in presence or absence of Blue-winged Warbler. According to Monte Carlo analyses, orchardgrass (Dactylis glomerata, green ash (Fraxinus pennsylvanica seedlings and saplings, and black locust (Robinia pseudoacacia saplings were indicative of sites with only Golden-winged Warblers. Sericea lespedeza, goldenrod (Solidago spp., clematis vine (Clematis spp., and blackberry (Rubus spp. were indicative of sites where both species occurred. Our findings complement recent genetic studies and add

  1. Application of organic waste composts when producing forest planting material

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    Romanov Evgeny M.

    2016-01-01

    Full Text Available Most seedlings and saplings of woody plants in the Russian Federation are produced in the open ground in forest nurseries. In order to produce high quality planting material it is necessary to support and preserve soil fertility, which can be obtained by using organic wastes and organic-based fertilizers. Our research is aimed at the assessment of the influence of non-conventional organic fertilizers on fertility of podzols and on the growth rate of seedlings and saplings of woody plants in forest nurseries. Our research shows, that the application of non-conventional organic fertilizers does not result in any accumulation of heavy metal salts in podzols, but optimizes hydro physical and agrochemical properties of the ploughed horizon. The efficiency of non-conventional organic fertilizers depends on their composition, physical and chemical characteristics of the original components, their doses applied and original fertility of soils. A combined application of non-conventional organic fertilizers and sand results in the optimization of practically all soil fertility parameters in middle clay-loam soils, while application of non-conventional organic fertilizers and clay is optimal for application on light soils. The optimal application dose of non-conventional fertilizers depends on soil texture, woody species and the fertilizer composition. An optimal application dose for Norway spruce on a light clay-loam soil is 50-80 tons/ha, and on a middle clay-loam soil is 149-182 tons/ha. It is 50 tons/ha for Scots pine growing on a sandy loam soil, and 100 tons/ha for the same species growing on a sandy soil or a light clay-loam. For Siberian larch growing on a light clay-loam soil the dose of fertilizer applied should be 150 tons/ha. It is recommended to apply composts containing over 50% (by weight of Category II wastes (substrate for the amelioration of light soils, and composts containing over 40% (by weight of Category I wastes (filler for the

  2. TEK, local perceptions of risk, and diversity of management practices of Agave inaequidens in Michoacán, Mexico.

    Science.gov (United States)

    Torres, Ignacio; Blancas, José; León, Alejandro; Casas, Alejandro

    2015-08-05

    Mescal production is the main economic activity associated to agaves in Mexico, which involves 53 species mostly harvested from forests. The increasing mescal demand has influenced risk in both agave populations and mescal production, but other social and ecological factors also intervene. We hypothesized that the greater the risk the greater the complexity of management responses; otherwise, the greater the probability of populations' depletion. We analysed this hypothesis by examining the diversity of risk conditions and management practices of Agave inaequidens in the state of Michoacán, in central-western Mexico. We studied five communities of Michoacán, documenting through 41 semi-structured interviews the use forms, risk perception, number of agaves annually extracted, and the management practices. Using a matrix with social-ecological and technological data analyzed by PCA, we evaluated similarities of management contexts. A data matrix with information on risk of agave populations, and other about management practices were analysed also through CCA and PCA. The scores of the first principal components were considered as indexes of risk and management complexity, respectively. A regression analysis of these indexes evaluated their relation. We recorded 34 different uses of A. inaequidens, the most important being mescal production (mentioned by 76.1 % of people interviewed). Nearly 12.5 % of people practice only gathering, but others mentioned the following practices: Selective let standing of agaves for seed production (20 %); in situ transplanting of saplings; seed propagation in nurseries and saplings transplanting to forest (10 %); suckers transplanting (7.5 %); seed dispersal in forests; banning (5 %); enhancing of agave growth by removing tree canopies (2.5 %); transplanting from the wild to live fences (45 %); intensive plantations (35 %). The highest vulnerability of agave populations was identified in communities where risk is not counteracted by

  3. The C-household of young broad-leaved and conifer tree species exposed to long-term carbon limitation by shading

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    Weber, Raphael; Hoch, Günter

    2017-04-01

    Non-structural carbohydrates (NSC, i.e. free sugars and starch) are regarded as freely available carbon (C) reserves in plants. They are often quantified to estimate a plant's C-balance, assuming that NSC are controlled by the net-balance between photo-assimilation and C-usage (respiration, growth and other sinks). Within a recent field experiment, we investigated the extent, to which C-reserves (NSC) can be formed in young trees against prevailing C-sink demands (growth) under C-limitation. A total of almost 1000 individuals of two-year-old tree saplings from 6 deciduous, broadleaved species and 4 evergreen conifer species were planted on a field side. Half of the trees per species were treated with long-term C-limitation by exposing them to continuous deep shade conditions (5% of natural PPFD) under a permanent shading tent. C gas-exchange, growth and NSC tissue concentrations were analyzed in shaded and unshaded saplings for two consecutive years. Three months after the beginning of the experiment, leaf photosynthesis acclimatized to the low light conditions, with leaves of shaded trees showing significantly higher SLA and lower light saturation and maximum photosynthesis. During the second season of the experiment, most species exhibited very strong reductions in NSC, but much less pronounced reductions in growth. In contrast, other species, with few exceptions, kept NSC concentrations similar to unshaded controls, while growth virtually stopped under deep shade. In conclusion, we found species-specific strategies in the trees' C-household after two years of C-limitation, that fall into two major carbon allocation strategies: 1) "C-spenders", which deplete C reserves in order to keep up significant growth, and 2) "C-savers", which reduce C sink activities to a minimum in order to store substantial amounts of C reserves. Overall, early-successional species tended to follow the first strategy, while late-successional species tended to save higher C reserve pools

  4. Differences in fine-scale genetic structure and dispersal in Quercus ilex L. and Q. suber L.: consequences for regeneration of mediterranean open woods.

    Science.gov (United States)

    Soto, A; Lorenzo, Z; Gil, L

    2007-12-01

    Cork oak (Quercus suber L.) and holm oak (Q. ilex L.) are among the most important tree species (economically and ecologically) in the Western Mediterranean region, where they define unique open woods (created and maintained by man) known as 'dehesas' in Spain. However, these formations are under increasing threat due to the lack of regeneration. We have analysed spatial genetic structure in a mixed parkland; inferences about gene dispersal have also been performed, according to the isolation by distance model. Noticeable differences have been detected between the species, despite their similar ecological roles. Restricted effective dispersal leads to kin structures in cork oak, up to 70 m, while no genetic structure is observed in holm oak. Our results suggest a very effective dispersal for the latter, with a local historical gene flow estimated between 55 and 95 m. This is the first time regeneration of Mediterranean oak parklands has been assessed from a genetic perspective. Effective gene flow detected for holm oaks allows us to discount the risk of inbreeding over successive generations. Thus, regeneration of Q. ilex dehesas will just require action directed to help the settlement of the saplings (such as limiting grazing). However, in those cases where densities are too low, more intense forestation (such as plantation and/or establishment of appropriate shelter) will be needed. The 'density threshold' for initiating regeneration will probably be higher for cork oak, due to its more limited dispersal and minor full-light tolerance.

  5. Diversity and specificity of ectomycorrhizal fungi retrieved from an old-growth Mediterranean forest dominated by Quercus ilex.

    Science.gov (United States)

    Richard, F; Millot, S; Gardes, M; Selosse, M-A

    2005-06-01

    We analysed the ectomycorrhizal (ECM) fungal diversity in a Mediterranean old-growth Quercus ilex forest stand from Corsica (France), where Arbutus unedo was the only other ECM host. On a 6400 m2 stand, we investigated whether oak age and host species shaped below-ground ECM diversity. Ectomycorrhizas were collected under Q. ilex individuals of various ages (1 yr seedlings; 3-10 yr saplings; old trees) and A. unedo. They were typed by ITS-RFLP analysis and identified by match to RFLP patterns of fruitbodies, or by sequencing. A diversity of 140 taxa was found among 558 ectomycorrhizas, with many rare taxa. Cenococcum geophilum dominated (35% of ECMs), as well as Russulaceae, Cortinariaceae and Thelephoraceae. Fungal species richness was comparable above and below ground, but the two levels exhibited Quercus ilex age did not strongly shape ECM diversity. The two ECM hosts, A. unedo and Q. ilex, tended to share few ECM species (< 15% of the ECM diversity). Implications for oak forest dynamics are discussed.

  6. Land Use and Land Cover Change, and Woody Vegetation Diversity in Human Driven Landscape of Gilgel Tekeze Catchment, Northern Ethiopia

    Directory of Open Access Journals (Sweden)

    Samuale Tesfaye

    2014-01-01

    Full Text Available Land use and land cover (LULC change through inappropriate agricultural practices and high human and livestock population pressure have led to severe land degradation in the Ethiopian highlands. This has led to further degradation such as biodiversity loss, deforestation, and soil erosion. The study examined woody vegetation diversity status and the impact of drivers of change across different LULC types and agroecological zones in Gilgel Tekeze catchment, northern Ethiopian highlands. LULC dynamics were assessed using GIS techniques on 1976, 1986, and 2008 satellite images. Vegetation data were collected from 135 sample plots (20 m × 20 m from five LULC types, namely, forest, shrub-bush, grazing, settlement, and cultivated land, in the three agroecological zones; Kolla, Weyna-Dega, and Dega. Differences in vegetation structure and composition and their relationship to agroecological zones were tested using two-way ANOVA and PCA technique. The results show that vegetation structure and composition significantly differed across all LULC types in different agroecological zones particularly in sapling density, tree height, and shrub height and in each agroecological zone between forest land, shrub-bush land, and settlement area. Overall, Weyna-Dega agroecological zone and the shrub-bush land had more structural and compositional diversity than the other agroecological zones and LULC types.

  7. Describing Paenibacillus mucilaginosus strain N3 as an efficient plant growth promoting rhizobacteria (PGPR

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    Dweipayan Goswami

    2015-12-01

    Full Text Available Bacterium Paenibacillus mucilaginosus strain N3 was isolated from agricultural farm soil (located at Boriavi village, Gujarat, India. Isolate showed an evidence of non-symbiotic nitrogen fixation, when grown in nitrogen-free bromothymol blue growth medium. It was tested positive for direct plant-growth-promoting traits like Indole-3-acetic acid production, solubilization of Tri-calcium-phosphate, and ammonia production. Further, N3 isolate was tested positive for siderophore production of catecholate type and catalase production as an indirect plant-growth-promoting trait. Biochemical tests along with 16s rRNA gene sequence analysis confirmed the strain N3 to be P. mucilaginosus. To determine its efficacy as a plant-growth-promoting rhizobacteria (PGPR, its talc-based biofertilizer was prepared and tested on the growth of green gram (Vigna radiata. Seeds treated with this biofertilizer showed an increase in overall dry biomass by 17% and sapling length by 28% (as compared to non-treated controls after 10 days of sowing in pots. Thus, multiple plant-growth-promoting traits of P. mucilaginosus N3 determined in vitro along with its ability to promote growth in green gram in vivo we characterize this strain as an efficient PGPR.

  8. Wood properties of Populus and Betula in long-term exposure to elevated CO₂ and O₃.

    Science.gov (United States)

    Kostiainen, Katri; Saranpää, Pekka; Lundqvist, Sven-Olof; Kubiske, Mark E; Vapaavuori, Elina

    2014-06-01

    We studied the interactive effects of elevated concentrations of CO2 and O3 on radial growth and wood properties of four trembling aspen (Populus tremuloides Michx.) clones and paper birch (Betula papyrifera Marsh.) saplings. The material for the study was collected from the Aspen FACE (free-air CO2 enrichment) experiment in Rhinelander (WI, USA). Trees had been exposed to four treatments [control, elevated CO2 (560 ppm), elevated O3 (1.5 times ambient) and combined CO2 + O3 ] during growing seasons 1998-2008. Most treatment responses were observed in the early phase of experiment. Our results show that the CO2- and O3-exposed aspen trees displayed a differential balance between efficiency and safety of water transport. Under elevated CO2, radial growth was enhanced and the trees had fewer but hydraulically more efficient larger diameter vessels. In contrast, elevated O3 decreased radial growth and the diameters of vessels and fibres. Clone-specific decrease in wood density and cell wall thickness was observed under elevated CO2 . In birch, the treatments had no major impacts on wood anatomy or wood density. Our study indicates that short-term impact studies conducted with young seedlings may not give a realistic view of long-term ecosystem responses. © 2013 John Wiley & Sons Ltd.

  9. Amphibian and reptile abundance in riparian and upslope areas of five forest types in western Oregon

    Science.gov (United States)

    Gomez, D.M.; Anthony, R.G.

    1996-01-01

    We compared species composition and relative abundance of herpetofauna between riparian and upslope habitats among 5 forest types (shrub, open sapling-pole, large sawtimber and old-growth conifer forests, and deciduous forests) in Western Oregon. Riparian- and upslope- associated species were identified based on capture frequencies from pitfall trapping. Species richness was similar among forest types but slightly greater in the shrub stands. The abundances of 3 species differed among forest types. Total captures was highest in deciduous forests, intermediate in the mature conifer forests, and lowest in the 2 young coniferous forests. Species richness was similar between stream and upslope habitats; however, captures were higher in riparian than upslope habitat. Tailed frogs (Ascaphus truei), Dunn's salamanders (Plethodon dunni), roughskin newts(Tanicha granulosa), Pacific giant salamanders (Dicamptodon tenebrosus) and red-legged frogs(Rana aurora) were captured more frequently in riparian than upslope habitats. Of these species the red-legged frog and Pacific giant salamander may depend on riparian habitat for at least part of their life requirements, while tailed frogs, Dunn's salamanders and roughskin newts appear to be riparian associated species. In addition, we found Oregon salamanders (Ensatina eschscholtzi) were associated with upslope habitats. We suggest riparian management zones should be al least 75-100 m on each side of the stream and that management for upslope/and or old forest associates may be equally as important as for riparian species.

  10. Effects of sap-feeding insect herbivores on growth and reproduction of woody plants: a meta-analysis of experimental studies.

    Science.gov (United States)

    Zvereva, Elena L; Lanta, Vojtech; Kozlov, Mikhail V

    2010-08-01

    The majority of generalisations concerning plant responses to herbivory are based on studies of natural or simulated defoliation. However, effects caused by insects feeding on plant sap are likely to differ from the effects of folivory. We assessed the general patterns and sources of variation in the effects of sap feeding on growth, photosynthesis, and reproduction of woody plants through a meta-analysis of 272 effect sizes calculated from 52 papers. Sap-feeders significantly reduced growth (-29%), reproduction (-17%), and photosynthesis (-27%); seedlings suffered more than saplings and mature trees. Deciduous and evergreen woody plants did not differ in their abilities to tolerate damage imposed by sap-feeders. Different plant parts, in particular below- and above-ground organs, responded similarly to damage, indicating that sap-feeders did not change the resource allocation in plants. The strongest effects were caused by mesophyll and phloem feeders, and the weakest by xylem feeders. Generalist sap-feeders reduced plant performance to a greater extent than did specialists. Methodology substantially influenced the outcomes of the primary studies; experiments conducted in greenhouses yielded stronger negative effects than field experiments; shorter (plants by sap-feeders. Studies conducted at higher temperatures yielded stronger detrimental effects of sap-feeders on their hosts. We conclude that sap-feeders impose a more severe overall negative impact on plant performance than do defoliators, mostly due to the lower abilities of woody plants to compensate for sap-feeders' damage in terms of both growth and photosynthesis.

  11. Vegetation types, dominant compositions, woody plant diversity and stand structure in Trishna Wildlife Sanctuary of Northeast India.

    Science.gov (United States)

    Majumdar, Koushik; Datta, B K

    2015-03-01

    Present study was carried out to assess the vegetation types, diversity and phytosociological status of woody plants in Trishna Wildlife Sanctuary of Tripura, Northeast India. Vegetation data was derived by 25 line transects (10 m wide and 500 m length, each 0.5 ha size). All woody species at >10 cm gbh (Girth at Breast Height) within each plots were measured and counted. A total of six forest types were classified by cluster analysis using Importance Value Index (IVI) of 289 woody species. Species diversity, forest structure and woody community associations were evaluated and discussed. One way ANOVA revealed significant differences in all species diversity measures and stand structure along the forest types. Distribution of stem density at ten different gbh classes showed reverse J-shaped curves. Population status of woody plants was also examined through grouping of all individuals into four population age stages viz. sapling ( or = 30 - 120 - 210 cm gbh) and old (> or =210 cm). To observe dominant composition and species population trend, IVI of top ten dominant species from all forest types were tabulated. The present study suggested that Trishna Wildlife Sanctuary is an important habitat in Tripura from floristic point of view and it should be conserved on priority basis for remaining wildlife endurances and monitor for forest livelihoods products for sustainable biodiversity conservation in this region.

  12. Impact of wild herbivorous mammals and birds on the altitudinal and northern treeline ecotones

    Directory of Open Access Journals (Sweden)

    Friedrich-Karl Holtmeier

    2012-10-01

    Full Text Available Wild herbivorous mammals may damage treeline vegetation an cause soil erosion at a local scale. In many high mountain areas of Europe and North America, large numbers of red deer have become a threat to the maintenance of high-elevation forests and attempts to restore the climatic treeline. In northern Fennoscandia, overgrazing by reindeer in combination with mass outbreaks of the autumnal moth are influencing treeline dynamics. Moose are also increasingly involved damaging treeline forest. In the Alps, the re-introduction of ibex is causing local damage to subalpine forests and tree establishment above the forest limit as well as aggravating soil erosion. High-elevation forests and treeline in Europe are susceptible to the deleterious impact of wild ungulate populations because of former extensive pastoral use. Rodents may damage tree seedlings and saplings by girdling, root cutting, bark stripping and burrowing. Hares damage young trees by gnawing. Large numbers of small rodents may occasionally impede tree regeneration by depleting the seed sources. Rodents do not contribute to forest expansion beyond the current treeline. Among birds, nutcrackers are highly effective in influencing tree distribution patterns and treeline dynamics. Without the nutcracker caching of stone pine seeds any upward advance of the trees in response to climatic warming would be impossible. Some bird species such as black grouse, willow grouse and ptarmigan can impair tree growth by feeding on buds, catkins and fresh terminal shoots.

  13. Acute and long-term effects of irradiation on pine (Pinus silvestris) stands post-Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, N.P.; Kuchma, N.D. (Department of Radiology and Land Restoration, Pripyat Research and Industrial Association, Chernobyl (Ukraine)); Askbrant, S. (National Radiation Protection Institute, Stockholm (Sweden)); Pasternak, P.S.; Musica, V.V. (Lyes Research and Industrial Association, Kharykov (Ukraine))

    1994-10-14

    The effect of ionizing irradiation on the viability of pine stands after the fallout from the damaged nuclear energy plant at Chernobyl (ChNPP) was shown within the territory of the 10-km zone. During the period 1986-1991, irradiated and damaged forest stands, so-called 'red forest', located in this area were systematically classified by observation. Mortality rate, re-establishment, development of tree canopies, reproduction anomalies and stand viability were shown to be dependent on absorbed irradiation dose, on the age of the stand and on forest composition. For pine stands in the acutely affected zone, doses of more than 60 Gy resulted in a massive mortality and no regeneration of pine trees since 1987. The injured trees had burned or had dried-up. The drying process was accelerated by a massive production of pathogenic insects invading the dying trees. Specifically, irradiation doses of 10-60 Gy, 1-10 Gy and 0.1-1 Gy caused high, medium and low injury to the forest stands, respectively. Doses of less than 0.1 Gy did not cause any visible damage to the trees. In 1987, repair processes were displayed by the tree canopies and practically the entire viability of the forest stands had recovered except for trees in the acute and highly affected zones. The young forest was reestablished in the same place as the perished trees and new pine saplings were planted on the reclaimed areas.

  14. Brown world forests: increased ungulate browsing keeps temperate trees in recruitment bottlenecks in resource hotspots.

    Science.gov (United States)

    Churski, Marcin; Bubnicki, Jakub W; Jędrzejewska, Bogumiła; Kuijper, Dries P J; Cromsigt, Joris P G M

    2017-04-01

    Plant biomass consumers (mammalian herbivory and fire) are increasingly seen as major drivers of ecosystem structure and function but the prevailing paradigm in temperate forest ecology is still that their dynamics are mainly bottom-up resource-controlled. Using conceptual advances from savanna ecology, particularly the demographic bottleneck model, we present a novel view on temperate forest dynamics that integrates consumer and resource control. We used a fully factorial experiment, with varying levels of ungulate herbivory and resource (light) availability, to investigate how these factors shape recruitment of five temperate tree species. We ran simulations to project how inter- and intraspecific differences in height increment under the different experimental scenarios influence long-term recruitment of tree species. Strong herbivore-driven demographic bottlenecks occurred in our temperate forest system, and bottlenecks were as strong under resource-rich as under resource-poor conditions. Increased browsing by herbivores in resource-rich patches strongly counteracted the increased escape strength of saplings in these patches. This finding is a crucial extension of the demographic bottleneck model which assumes that increased resource availability allows plants to more easily escape consumer-driven bottlenecks. Our study demonstrates that a more dynamic understanding of consumer-resource interactions is necessary, where consumers and plants both respond to resource availability. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  15. Provenance-specific growth responses to drought and air warming in three European oak species (Quercus robur, Q. petraea and Q. pubescens).

    Science.gov (United States)

    Arend, Matthias; Kuster, Thomas; Günthardt-Goerg, Madeleine S; Dobbertin, Matthias

    2011-03-01

    Provenance-specific growth responses to experimentally applied drought and air warming were studied in saplings of three European oak species: Quercus robur, Quercus petraea and Quercus pubescens. Four provenances of each species were grown in large open-top chambers and subjected to four climates: control, periodic drought, air warming or their combination in 3 subsequent years. Overall growth responses were found among species and provenances, with drought reducing shoot height growth and stem diameter growth and air warming stimulating shoot height growth but reducing stem diameter growth and root length growth. Differential growth responses in shoots, stems and roots resulted in altered allometric growth relations. Root length growth to shoot height growth increased in response to drought but decreased in response to air warming. Stem diameter growth to shoot height growth decreased in response to air warming. The growth responses in shoots and stems were highly variable among provenances indicating provenance-specific sensitivity to drought and air warming, but this response variability did not reflect local adaptation to climate conditions of provenance origin. Shoot height growth was found to be more sensitive to drought in provenances from northern latitudes than in provenances from southern latitudes, suggesting that genetic factors related to the postglacial immigration history of European oaks might have interfered with selective pressure at provenance origins.

  16. Floristics of mangrove tree species in Angke-Kapuk Protected Forest

    Directory of Open Access Journals (Sweden)

    RUGAYAH

    2005-01-01

    Full Text Available Angke-Kapuk Protected Forest with total area 44.76 ha is part of the Tegal Alur-Angke Kapuk mangrove forests. Therefore, this forest has important role as an interface between terrestrial and marine ecosystems, whether physical, biological or social-economic aspects, to determine mangrove ecosystem as a productive and unique ecosystem in the coastal area. However, the study of floristic of the mangrove vegetation in this forest has never to be done previously. According to the study on September to November 2003, in this forest found 8 species of mangrove trees. The tree species can be classified into two groups. The first group is true mangroves (7 species, i.e. Avicennia officinalis, Rhizophora apiculata, R. mucronata, R. stylosa, Sonneratia caseolaris (major component, Excoecaria agallocha, and Xylocarpus moluccensis (minor component. The last group is mangrove associate, i.e. Terminalia catappa. In this forest also found 7 tree species, i.e. Bruguiera gymnorrhiza, Calophyllum inophyllum, Cerbera manghas, Paraserianthes falcataria, Tamarindus indicus, Acacia mangium, and A. auriculiformis as introduced species. The growth level of B. gymnorhiza, C. inophyllum and C. manghas up to now is seedling and sapling, while the growth level of another introduced species is till in pole and tree.

  17. Influence of Mature Overstory Trees on Adjacent 12-Year Regeneration and the Woody Understory: Aggregated Retention versus Intact Forest

    Directory of Open Access Journals (Sweden)

    Miranda T. Curzon

    2017-01-01

    Full Text Available Retention harvesting, an approach that intentionally retains legacy features such as mature overstory trees, provides options for achieving ecological objectives. At the same time, retained overstory trees may compete with the nearby recovering understory for resources, and much remains to be learned about potential trade-offs with regeneration objectives, particularly over extended time periods. We assessed the influence of aggregated retention (reserved mature overstory and understory patches versus intact forest on structure and productivity (standing biomass of the adjacent woody understory and regeneration 12 years after harvest in northern Minnesota, USA. Each site was dominated by Populus tremuloides Michx., a species that regenerates prolifically via root sprouts following disturbance. Overall, fewer differences than expected occurred between the effects of intact forest and aggregated retention on regeneration, despite the small size (0.1 ha of aggregates. Instead, harvest status and distance from harvest edge had a greater influence on structure and standing woody biomass. Proximity to aggregates reduced large sapling biomass (all species, combined relative to open conditions, but only up to 5 m into harvested areas. This suggests the trade-off for achieving productivity objectives might be minimal if managers use retention aggregates in this region to achieve ecological objectives and meet management guidelines.

  18. Grafting guava on cattley guava resistant to Meloidogyne enterolobii

    Directory of Open Access Journals (Sweden)

    Renata Rodrigues Robaina

    2015-09-01

    Full Text Available The use of resistant rootstocks could be a promising method to control nematodeMeloidogyne enterolobiiin commercial plantations of guava. The present study aimed to evaluate the success of grafting guava as a scion on accessions of cattley guava as rootstocks resistant to M. enterolobii.The treatments consisted of the rootstocks cattley guava plants (three accessions of Psidium cattleyanum and common guava (control. In the apical wedge grafting method, scion of Paluma cultivated variety was used. The experiment was arranged in a randomized block design with four treatments and five replicates, and eight plants per plot. The saplings produced as described before were planted in the field where the initial growth of the different combinations were evaluated. Graft success was observed for the control (common guava and for accessions 115 and 117 of cattley guava plants, with success rates of 63, 32 and 29%, respectively. In the field, the cattley guava used as rootstocks hampered Paluma canopy development and caused death of plants. Incompatibility of P. cattleyanumas rootstocks for P. guajavaPaluma was confirmed one year after cultivation in field.

  19. Psidium guajava 'Paluma' (the guava plant) as a new bio-indicator of ozone in the tropics

    Energy Technology Data Exchange (ETDEWEB)

    Furlan, C.M. [Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, CP 11461, 05422-970 Sao Paulo, SP (Brazil)]. E-mail: furlancm@yahoo.com.br; Moraes, R.M. [Instituto de Botanica, SMA, CP 4005, 01061-970 Sao Paulo (Brazil); Bulbovas, P. [Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, CP 11461, 05422-970 Sao Paulo, SP (Brazil); Domingos, M. [Instituto de Botanica, SMA, CP 4005, 01061-970 Sao Paulo (Brazil); Salatino, A. [Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, CP 11461, 05422-970 Sao Paulo, SP (Brazil); Sanz, M.J. [Fundacion Centro de Estudios Ambientales del Mediterraneo, C/C. Darwin, 14, 46980 Paterna, Valencia (Spain)

    2007-06-15

    Psidium guajava 'Paluma' saplings were exposed to carbon filtered air (CF), ambient non-filtered air (NF), and ambient non-filtered air + 40 ppb ozone (NF + O{sub 3}) 8 h per day during two months. The AOT40 values at the end of the experiment were 48, 910 and 12 895 ppb h{sup -1}, respectively for the three treatments. After 5 days of exposure (AOT40 = 1497 ppb h{sup -1}), interveinal red stippling appeared in plants in the NF + O{sub 3} chamber. In the NF chamber, symptoms were observed only after 40 days of exposure (AOT40 = 880 ppb h{sup -1}). After 60 days, injured leaves per plant corresponded to 86% in NF + O{sub 3} and 25% in the NF treatment, and the average leaf area injured was 45% in NF + O{sub 3} and 5% in the NF treatment. The extent of leaf area injured (leaf injury index) was explained mainly by the accumulated exposure of ozone (r {sup 2} = 0.91; p < 0.05). - Psidium guajava 'Paluma', a tropical species widely used in Brazilian food industry, is a potential sensitive bio-indicator of ozone.

  20. Forest fire in the central Himalaya: climate and recovery of trees

    Science.gov (United States)

    Sharma, Subrat; Rikhari, H. C.

    A forest fire event is influenced by climatic conditions and is supported by accumulation of fuel on forest floor. After forest fire, photosynthetically active solar radiation was reduced due to accumulation of ash and dust particles in atmosphere. Post-fire impacts on Quercus leucotrichophora, Rhododendron arboreum and Lyonia ovalifolia in a broadleaf forest were analysed after a wild fire. Bark depth damage was greatest for L. ovalifolia and least for Q. leucotrichophora. Regeneration of saplings was observed for all the tree species through sprouting. Epicormic recovery was observed for the trees of all the species. Young trees of Q. leucotrichophora (<40 cm circumference at breast height) were susceptible to fire as evident by the lack of sprouting. Under-canopy tree species have a high potential for recovery as evident by greater length and diameter of shoots and numbers of buds and leaves per shoot than canopy species. Leaf area, leaf moisture and specific leaf area were greater in the deciduous species, with few exceptions, than in evergreen species.

  1. Assessment of the efficiency of the aleppo pine Pinus halepensis Mill. natural regeneration in the Eastern Mediterranean on example of Israel

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    S. M. Sprintsin

    2017-04-01

    Full Text Available This paper deals with the management of Mediterranean Planted Conifer Forests (MPCF, dominated by the aleppo pine Pinus halepensis and the potential for using natural regeneration as a basis for transformation of simply structured even-aged and mono crops plantations into mixed forest. We studied the variation along a rainfall gradient, in the natural regeneration of tree species. The study was conducted in four forests located within the Mediterranean zone of Israel, which extends from the semiarid northern Negev desert (rainfall ca. 300 mm per year in the south to the humid central region close the coast line (ca 550 mm per year. Standing trees measurements including mean tree height, diameter at breast height, crown width, canopy cover, stand density of the mature strata and the number of saplings and their species composition along with the landscape characteristics (slope, aspect, percentage of rock cover and forest floor light regime have been performed at randomly established 200 m2 area circular plots. Although a water supply is the main limiting resource for forest growth and productivity, so far no significant relationship between the quantity of regeneration and precipitation could be found. Strong linear correlation between the number of the mature trees and pine’s regeneration have been revealed and the detailed management plan of how to support a natural regeneration using a principal of Continues Cover Forestry was suggested for MPCF, including a recommendation for intensity and time of thinning.

  2. Hydraulic adjustments underlying drought resistance of Pinus halepensis.

    Science.gov (United States)

    Klein, Tamir; Cohen, Shabtai; Yakir, Dan

    2011-06-01

    Drought-induced tree mortality has increased over the last decades in forests around the globe. Our objective was to investigate under controlled conditions the hydraulic adjustments underlying the observed ability of Pinus halepensis to survive seasonal drought under semi-arid conditions. One hundred 18-month saplings were exposed in the greenhouse to 10 different drought treatments, simulating combinations of intensities (fraction of water supply relative to control) and durations (period with no water supply) for 30 weeks. Stomata closed at a leaf water potential (Ψ(l)) of -2.8 MPa, suggesting isohydric stomatal regulation. In trees under extreme drought treatments, stomatal closure reduced CO(2) uptake to -1 µmol m(-2) s(-1), indicating the development of carbon starvation. A narrow hydraulic safety margin of 0.3 MPa (from stomatal closure to 50% loss of hydraulic conductivity) was observed, indicating a strategy of maximization of CO2 uptake in trees otherwise adapted to water stress. A differential effect of drought intensity and duration was observed, and was explained by a strong dependence of the water stress effect on the ratio of transpiration to evapotranspiration T/ET and the larger partitioning to transpiration associated with larger irrigation doses. Under intense or prolonged drought, the root system became the main target for biomass accumulation, taking up to 100% of the added biomass, while the stem tissue biomass decreased, associated with up to 60% reduction in xylem volume.

  3. Genetic Structure of a Naturally Regenerating Post-Fire Seedling Population: Pinus halepensis As a Case Study.

    Science.gov (United States)

    Gershberg, Anna; Ne'eman, Gidi; Ben-Shlomo, Rachel

    2016-01-01

    To study the effects of wildfire on population genetics of a wind pollinated and wind dispersed tree, we have analyzed the genetic structure of a post-fire, naturally regenerating seedling population of Pinus halepensis Miller, on Mt. Carmel, Israel. We tested the existence of spatial genetic structure, which is expected due to the special spatial demographic structure of the post-fire seedling and sapling populations of this species. Explicitly, we asked whether or not seedlings that germinated under large, burned, dead pine trees are also their offspring. The results revealed that the post-fire seedling population is polymorphic, diverse, and reflects the pre-fire random mating system. In contrast to our prediction, we found no division of the post-fire seedling population to distinct sub-populations. Furthermore, as a result of post-fire seed dispersal to longer range than the average pre-fire inter-tree distance, seedlings found under individual burned trees were not necessarily their sole offspring. Although the population as a whole showed a Hardy-Weinberg equilibrium, significant excess of heterozygotes was found within each tallest seedlings group growing under single, large, burned pine trees. Our finding indicates the possible existence of intense natural selection for the most vigorous heterozygous genotypes that are best adapted to the special post-fire regeneration niche, which is the thick ash bed under large, dead, pine trees.

  4. The natural history of the arboreal ant, Crematogaster ashmeadi

    Directory of Open Access Journals (Sweden)

    Walter R. Tschinkel

    2002-07-01

    Full Text Available The arboreal ant, Crematogaster ashmeadi Emery (Hymenoptera: Formicidae, is the most dominant arboreal ant in the pine forests of the coastal plain of northern Florida. The majority of pine trees harbor a colony of these ants. The colonies inhabit multiple chambers abandoned by bark-mining caterpillars, especially those of the family Cossidae, in the outer bark of living pines. They also inhabit ground level termite galleries in the bark, often locating the queen in galleries. The density of chambers and ants is highest in the base of the tree and drops sharply with height on the trunk. Because chambers are formed in the inner layer of bark, they gradually move outward as more bark layers are laid down, eventually sloughing off the tree's outer surface. Chambers have a mean lifetime of about 25 yr. The abundant chambers in pine bark are excavated by a small population of caterpillars and accumulate over decades. Ant colonies also inhabit abandoned galleries of woodboring beetles in dead branches in the crowns of pines. Because newly mated queens found colonies in abandoned woodboring beetle galleries in the first dead branches that form on pine saplings, C. ashmeadi is dependent on cavities made by other insects throughout its life cycle, and does little if any excavation of its own. Mature colonies nest preferentially in chambers greater than 10 cm2 in area, a relatively rare chamber size. In natural pine forests, this does not seem to limit the ant's populations.

  5. Factors associated with long-term species composition in dry tropical forests of Central India

    Science.gov (United States)

    Agarwala, M.; DeFries, R. S.; Qureshi, Q.; Jhala, Y. V.

    2016-10-01

    The long-term future of species composition in forests depends on regeneration. Many factors can affect regeneration, including human use, environmental conditions, and species’ traits. This study examines the influence of these factors in a tropical deciduous forest of Central India, which is heavily used by local, forest-dependent residents for livestock grazing, fuel-wood extraction, construction and other livelihood needs. We measure size-class proportions (the ratio of abundance of a species at a site in a higher size class to total abundance in both lower and higher size classes) for 39 tree species across 20 transects at different intensities of human use. The size-class proportions for medium to large trees and for small to medium-sized trees were negatively associated with species that are used for local construction, while size class proportions for saplings to small trees were positively associated with those species that are fire resistant and negatively associated with livestock density. Results indicate that grazing and fire prevent non-fire resistant species from reaching reproductive age, which can alter the long term composition and future availability of species that are important for local use and ecosystem services. Management efforts to reduce fire and forest grazing could reverse these impacts on long-term forest composition.

  6. Fire effects on the population structure of Zanthoxylum rhoifolium Lam (Rutaceae in a Brazilian savanna

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    IA. Silva

    Full Text Available Since cerrado fires may impede the growth of seedlings into trees, they may shape the population of woody species. In this study, we assessed the effects of a severe fire on the population structure and spatial distribution of Zanthoxylum rhoifolium, a widespread cerrado tree. We were interested to know the importance of the resprouting and sexual reproduction in regenerating the population. The study area had been for about six years protected from fire, before a severe fire at the end of the dry season in 2006. We sampled and measured all individuals of Z. rhoifolium found in 80 plots of 25 m². We found 149 individuals before the fire and 112 after the fire, of which 77 were resprouts from burned seedlings and saplings. We did not find significant differences between the population structure before and after the fire. The spatial distribution of the population remained clumped after the fire. Thus, the Z. rhoifolium population was very resilient to a severe fire. We did not find any new seedlings. As a consequence, resprouting seems to be more important than sexual reproduction in promptly regenerating the Z. rhoifolium populations.

  7. Fire effects on the population structure of Zanthoxylum rhoifolium Lam (Rutaceae) in a Brazilian savanna.

    Science.gov (United States)

    Silva, I A; Valenti, M W; Silva-Matos, D M

    2009-08-01

    Since cerrado fires may impede the growth of seedlings into trees, they may shape the population of woody species. In this study, we assessed the effects of a severe fire on the population structure and spatial distribution of Zanthoxylum rhoifolium, a widespread cerrado tree. We were interested to know the importance of the resprouting and sexual reproduction in regenerating the population. The study area had been for about six years protected from fire, before a severe fire at the end of the dry season in 2006. We sampled and measured all individuals of Z. rhoifolium found in 80 plots of 25 m(2). We found 149 individuals before the fire and 112 after the fire, of which 77 were resprouts from burned seedlings and saplings. We did not find significant differences between the population structure before and after the fire. The spatial distribution of the population remained clumped after the fire. Thus, the Z. rhoifolium population was very resilient to a severe fire. We did not find any new seedlings. As a consequence, resprouting seems to be more important than sexual reproduction in promptly regenerating the Z. rhoifolium populations.

  8. Trophic cascades, invasive species and body-size hierarchies interactively modulate climate change responses of ecotonal temperate-boreal forest.

    Science.gov (United States)

    Frelich, Lee E; Peterson, Rolf O; Dovčiak, Martin; Reich, Peter B; Vucetich, John A; Eisenhauer, Nico

    2012-11-05

    As the climate warms, boreal tree species are expected to be gradually replaced by temperate species within the southern boreal forest. Warming will be accompanied by changes in above- and below-ground consumers: large moose (Alces alces) replaced by smaller deer (Odocoileus virginianus) above-ground, and small detritivores replaced by larger exotic earthworms below-ground. These shifts may induce a cascade of ecological impacts across trophic levels that could alter the boreal to temperate forest transition. Deer are more likely to browse saplings of temperate tree species, and European earthworms favour seedlings of boreal tree species more than temperate species, potentially hindering the ability of temperate tree species to expand northwards. We hypothesize that warming-induced changes in consumers will lead to novel plant communities by changing the filter on plant species success, and that above- and below-ground cascades of trophic interactions will allow boreal tree species to persist during early phases of warming, leading to an abrupt change at a later time. The synthesis of evidence suggests that consumers can modify the climate change-induced transition of ecosystems.

  9. Mortality, recruitment and change of desert tree populations in a hyper-arid environment.

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    Gidske L Andersen

    Full Text Available BACKGROUND: Long-term vegetation changes in hyper-arid areas have long been neglected. Mortality, recruitment and change in populations of the ecologically and culturally important and drought persistent Acacia tortilis and Balanites aegyptiaca are therefore estimated in the Eastern Desert of Egypt, and are related to the primary agents of change, water conditions and human intervention. METHODOLOGY: A change analysis using high-resolution Corona images (1965 in combination with field data (2003 is the basis for recruitment, mortality and change estimates. For assessing the influence of water conditions on patterns in recruitment and survival, different types of generalized linear models are tested. CONCLUSIONS: The overall trend in population size in that part of the Eastern Desert studied here is negative. At some sites this negative trend is alarming, because the reduction in mature trees is substantial (>50% at the same time as recruitment is nearly absent. At a few sites there is a positive trend and better recruitment. Frequent observations of sprouting in saplings indicate that this is an important mechanism to increase their persistence. It is the establishment itself that seems to be the main challenge in the recruitment process. There are indications that hydrological variables and surface water in particular can explain some of the observed pattern in mortality, but our results indicate that direct human intervention, i.e., charcoal production, is the main cause of tree mortality in the Eastern Desert.

  10. EFFECT OF COMPLEX ORGANIC COMPOUNDS ON GROWTH PLANLET OF DENDROBIUM ORCHID

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    Sitti Raodah Garuda

    2015-01-01

    Full Text Available Uniqueness of stunning Dendrobium variety such as shapes, colors, and sizes are main attraction of this plant. Germination oforchid seeds can be carried out in a laboratory with in vitro techniques.Medium used for germination of orchid seeds are Vacin and Went medium. Researcher stried to add other substances that may increase growth explants, such as complex organic compounds. Study aims to determine effect of complex organic compounds into growth medium VW Dendrobium plantlets. Research used complete randomized design consist five treatment:VW medium without extract (control, VW medium+banana extract, VW medium+ melon extrac, VW medium+guava extract and VW medium+pepaya extract, with three replications, each replication consist two culture bottles.. Each culture bottle planted four planlets. Addition of complex organic compounds such as melon extract gave best vegetative growth of leaves quantity, roots quantity, root length and fresh weight. While guava extract provide best results to plantlet high and saplings. Plant lets with melon extract treatment showed appearance of muscular orchid plantlets is characteristic of plants that can survive during acclimatization. While both guava extract is best used for purpose of orchid plantlets regeneration.

  11. Foliar methyl salicylate emissions indicate prolonged aphid infestation on silver birch and black alder.

    Science.gov (United States)

    Blande, James D; Korjus, Minna; Holopainen, Jarmo K

    2010-03-01

    It is well documented that when plants are damaged by insects they respond by emitting a range of volatile organic compounds (VOCs). While there have been numerous reports concerning VOCs induced by chewing herbivores, there are relatively few studies detailing the VOCs induced by aphid feeding. The effects of aphid feeding on VOCs emitted by boreal forest trees have been particularly neglected. Herbivore-induced VOCs have relevance to direct and indirect plant defence and atmospheric chemistry. In this study, we analysed the VOCs emitted by Betula pendula (Roth) and Alnus glutinosa (L.) (Gaertn.) infested by specialist aphid species under laboratory conditions. We also complemented this by collecting VOCs from leaf beetle-damaged saplings under field conditions. In addition to induction of some inducible terpenes, we detected substantial aphid-induced emissions of methyl salicylate (MeSA) in both B. pendula and A. glutinosa. MeSA emission intensity depended on the length of aphid infestation. Feeding by beetles induced emission of (E)-DMNT in both tree species and (E)-beta-ocimene in A. glutinosa but had no effect on MeSA emissions. MeSA has been shown to have aphid-repellent qualities and has been shown recently to have impact on formation of secondary organic aerosols in the atmosphere. We discuss our results in relation to these two phenomena.

  12. Enhancement of understory productivity by asynchronous phenology with overstory competitors in a temperate deciduous forest.

    Science.gov (United States)

    Jolly, William M; Nemani, Ramakrishna; Running, Steven W

    2004-09-01

    Some saplings and shrubs growing in the understory of temperate deciduous forests extend their periods of leaf display beyond that of the overstory, resulting in periods when understory radiation, and hence productivity, are not limited by the overstory canopy. To assess the importance of the duration of leaf display on the productivity of understory and overstory trees of deciduous forests in the north eastern United States, we applied the simulation model, BIOME-BGC with climate data for Hubbard Brook Experimental Forest, New Hampshire, USA and mean ecophysiological data for species of deciduous, temperate forests. Extension of the overstory leaf display period increased overstory leaf area index (LAI) by only 3 to 4% and productivity by only 2 to 4%. In contrast, extending the growing season of the understory relative to the overstory by one week in both spring and fall, increased understory LAI by 35% and productivity by 32%. A 2-week extension of the growing period in both spring and fall increased understory LAI by 53% and productivity by 55%.

  13. Commercial Thinning to Meet Wood Production Objectives and Develop Structural Heterogeneity: A Case Study in the Spruce-Fir Forest, Quebec, Canada

    Directory of Open Access Journals (Sweden)

    Martin-Michel Gauthier

    2015-02-01

    Full Text Available We evaluated the effectiveness of commercial thinning mainly from below (CT; 0, 26%, 32% and 40% merchantable basal area removals in meeting wood production demands and developing structural heterogeneity in a balsam fir (Abies balsamea (L. Mill and spruce (Picea spp. stand. After 10 years, 32%–40% removals showed a 12%–18% increase in mean diameter and 27%–38% increase in gross merchantable volume (GMV per tree compared to the unthinned control. At the stand level, all thinning treatments generated as much cumulative GMV (harvested volume + GMV after 10 years and gross sawlog volume per hectare as the unthinned control. As for stand structure, eight out of nine thinned experimental units showed increased structural heterogeneity after 10 years, i.e., irregular, positively-skewed diameter distribution with an elongated right tail toward larger trees. The diameter distribution in the unthinned control became more symmetric, unimodal and regular over time, with fewer saplings than at the beginning of the experiment and lower density of larger trees compared to CT. Regeneration density and stocking were abundant in all treatments, largely dominated by balsam fir. Results indicate that thinning can be used to meet wood production objectives and help develop structural heterogeneity in this forest.

  14. Impacts of simulated herbivory on VOC emission profiles from coniferous plants

    Science.gov (United States)

    Faiola, C. L.; Jobson, B. T.; VanReken, T. M.

    2014-09-01

    The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsugas menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate, an herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.

  15. Impacts of simulated herbivory on volatile organic compound emission profiles from coniferous plants

    Science.gov (United States)

    Faiola, C. L.; Jobson, B. T.; VanReken, T. M.

    2015-01-01

    The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsuga menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate (MeJA), a herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.

  16. Honeybee, Apis mellifera (Hymenoptera: Apidae), leaf damage on Alnus species in Uganda: a blessing or curse in agroforestry?

    Science.gov (United States)

    Nyeko, P; Edwards-Jones, G; Day, R K

    2002-10-01

    It is a dictum that Apis mellifera Linnaeus is innocuous in agricultural ecosystems. This study provides the first record of A. mellifera as a significant defoliator of Alnus species. Careful field observations coupled with microscopic examination provided convincing evidence implicating A. mellifera as the cause of leaf perforation on Alnus species in Uganda. Apis mellifera was observed foraging selectively on young Alnus leaves and buds in search of a sticky substance, apparently propolis. In so doing, the bee created wounds that enlarged and caused tattering of Alnus leaves as they matured. Biological surveys indicated that the damage was prevalent and occurred widely, particularly on Alnus acuminata Kunth in Uganda. Incidence of the Apis mellifera damage on Alnus acuminata peaked in the dry season, with up to 90% of leaves emerging per shoot per month damaged, and was lowest in the wet months during peak leaf emergence. Apis mellifera leaf damage was consistently higher on Alnus acuminata than A. nepalensis D. Don., on saplings than mature trees, and on sun exposed than shaded leaves. The activity of honeybees may be detrimental to the productivity of Alnus, yet the substance for which the insect forages on Alnus is a resource with potential economic importance.

  17. Assessing redox potential of a native tree from the Brazilian Atlantic Rainforest: a successful evaluation of oxidative stress associated to a new power generation source of an oil refinery.

    Science.gov (United States)

    Esposito, Marisia Pannia; Pedroso, Andrea Nunes Vaz; Domingos, Marisa

    2016-04-15

    The antioxidant responses in saplings of Tibouchina pulchra (a native tree from the Brazilian Atlantic Rainforest) exposed around an oil refinery in the city of Cubatão (SE Brazil), varied during the exchange of its power generation source, from boilers fueled with oil to a thermoelectric fueled with natural gas. The redox potential changed in response to an interaction of air pollution and meteorological parameters, indicating that the pro-oxidant/antioxidant balance was not reached after the exchange of the power generation system. The gain in environmental quality in the region was not achieved as expected due the technological modernization, at least relative to oxidative stressors. These conclusions were based on results of analyses of enzymatic antioxidants: superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR); non-enzymatic antioxidants: reduced, oxidized and total ascorbic acid (AsA, DHA, totAA) and glutathione (GSH, GSSG, totG), their redox state (AsA/totAA and GSH/totG) and an indicator of lipid peroxidation (MDA). We also applied exploratory multivariate statistics in order to verify if the temporal sequence of changes in the plant redox capacity coincided with changes in the profile of air pollution, climatic conditions or with their interactions and if the environmental benefits that would supposedly be promoted by the mentioned exchange of power generation system were achieved in the region. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Analisis Vegetasi di Hutan Mbeji Daerah Wonosalam Jombang

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    Anita Munawwaroh

    2016-03-01

    Full Text Available Analisis vegetasi terhadap hutan perlu dilakukan untuk mengetahui keanekaragaman hayati yang terdapat di hutan tersebut sehingga mempermudah didalam melakukan pemeliharaan dan pemberdayaan hutan.Tujuan dari penelitian ini adalah untuk mengetahui keanekaragaman hayati dan struktur vegetasi (frekuensi, kerapatan, dominansi, dan Indeks Nilai Penting di hutan mbeji, Wonossalam, Jombang. Pada penelitian ini digunakan metode point centered quarter. Pennelitian dilakukan pada bulan Mei 2015. Hasil penelitian menujukkan padaHutan Mbeji terdapat 11 jenis pohon yang teridentifikasi dan 15 spesies tumbuhan, dimana ada 10 spesies yang telah teridentifikasiNilai penting  tumbuh-tumbuhan di Hutan Mbeji di daerah Wonosalam Jombang  pada tingkat pohon paling tinggi adalah pohon randu (Ceiba petandra  sebesar 57,42 % sedangkan nilai INP paling rendah dari jenis pohon andong (Rhadamnia cinerea yaitu sebesar 6,06 %. Pada sapling nilai penting yang paling tinggi adalah talas (Colocasia esculenta yaitu sebesar 49,23 %. Sedangkan, nilai INP paling rendah dari jenis nanas (Ananas comosus, nangka (Artocarpus heterophyllus, tapak liman (Elephantopus scaber, semak A, semak B, semak C, semak E, dan semak F yaitu sebesar 6,35 %. Tingginya nilai INP menunjukkan bahwa jenis-jenis tersebut dapat menyesuaikan diri dengan lingkungan sekitarnya yang lebih baik dibanding jenis lainnya.

  19. Horses help to maintain CERN's forests

    CERN Multimedia

    François Briard

    2016-01-01

    On the initiative of the Office National des Forêts, France’s forestry commission, horses are helping to remove trees cut down in CERN’s forests.   The CERN site covers 625 hectares, of which around 200 are fenced sites used for CERN’s research activities. The rest of the land consists of fields rented out to farmers and about 90 hectares of forests, mainly in France and managed by the French forestry commission, the Office National des Forêts (ONF), under an agreement with CERN signed in 2010. The upkeep of CERN’s forests requires regular maintenance work, which includes thinning out seedlings, selecting the strongest saplings and harvesting mature trees. This June, the ONF has decided to involve horses in the removal of felled trees from CERN’s woods in Prévessin.  As Florent Daloz, the logger entrusted with this activity by the ONF, explains, the use of horses to haul timber completely died out i...

  20. A long-scale biodiversity monitoring methodology for Spanish national forest inventory. Application to Álava region

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    Iciar Alberdi

    2014-04-01

    Full Text Available Aim of study: In this study, a methodology has been designed to assess biodiversity in the frame of the Spanish National Forest Inventory with the aim of evaluating the conservation status of Spanish forests and their future evolution. This methodology takes into account the different national and international initiatives together with the different types and characteristics of forests in Spain. Area of study: Álava province (Basque country, Spain.Material and methods: To analyse the contribution of each of the different indices to the biodiversity assessment, a statistical analysis using PCA multivariate techniques was performed for structure, composition and dead wood indicators. Main Results: The selected biodiversity indicators (based on field measurements are presented along with an analysis of the results from four representative forest types in Álava by way of an example of the potential of this methodology. Research highlights: The statistical analysis revealed the important information contribution of Mingling index to the composition indicators. Regarding the structure indicators, it is remarkable the interest of using standard deviations and skewness of height and diameter as indicators. Finally it is interesting to point out the interest of assessing dead saplings since they provide additional information and their volume is a particularly useful parameter for analyzing the success of regeneration.Keywords: species richness; structural diversity; dead wood; NFI; PCA.

  1. First records of tool-set use for ant-dipping by Eastern chimpanzees (Pan troglodytes schweinfurthii) in the Kalinzu Forest Reserve, Uganda.

    Science.gov (United States)

    Hashimoto, Chie; Isaji, Mina; Koops, Kathelijne; Furuichi, Takeshi

    2015-10-01

    Chimpanzees at numerous study sites are known to prey on army ants by using a single wand to dip into the ant nest or column. However, in Goualougo (Republic of Congo) in Central Africa, chimpanzees use a different technique, use of a woody sapling to perforate the ant nest, then use of a herb stem as dipping tool to harvest the army ants. Use of a tool set has also been found in Guinea, West Africa: at Seringbara in the Nimba Mountains and at nearby Bossou. There are, however, no reports for chimpanzees in East Africa. We observed use of such a tool set in Kalinzu, Uganda, for the first time by Eastern chimpanzees. This behavior was observed among one group of chimpanzees at Kalinzu (S-group) but not among the adjacent group (M-group) with partly overlapping ranging areas despite the fact that the latter group has been under intensive observation since 1997. In Uganda, ant-dipping has not been observed in the northern three sites (Budongo, Semliki, and Kibale) but has been observed or seems to occur in the southern sites (Kalinzu and Bwindi), which suggests that ant-dipping was invented by and spread from the southern region after the northern and southern forest blocks became separated. Use of a tool-set by only one group at Kalinzu further suggests that this behavior was recently invented and has not yet spread to the other group via migrating females.

  2. Carbon and oxygen isotope analysis of leaf biomass reveals contrasting photosynthetic responses to elevated CO2 near geologic vents in Yellowstone National Park

    Directory of Open Access Journals (Sweden)

    D. G. Williams

    2009-01-01

    Full Text Available In this study we explore the use of natural CO2 emissions in Yellowstone National Park (YNP in Wyoming, USA to study responses of natural vegetation to elevated CO2 levels. Radiocarbon (14C analysis of leaf biomass from a conifer (Pinus contortus; lodgepole pine and an invasive, non-native herb (Linaria dalmatica; Dalmation toadflax was used to trace the inputs of vent CO2 and quantify assimilation-weighted CO2 concentrations experienced by individual plants near vents and in comparable locations with no geologic CO2 exposure. The carbon and oxygen isotopic composition and nitrogen percent of leaf biomass from the same plants was used to investigate photosynthetic responses of these plants to naturally elevated atmospheric CO2 concentrations. The coupled shifts in carbon and oxygen isotope values suggest that dalmation toadflax responded to elevated CO2 exposure by increasing stomatal conductance with no change in photosynthetic capacity and lodgepole pine apparently responded by decreasing stomatal conductance and photosynthetic capacity. Lodgepole pine saplings exposed to elevated levels of CO2 likewise had reduced leaf nitrogen concentrations compared to plants with no enhanced CO2 exposure, further suggesting widespread and dominant conifer down-regulated photosynthetic capacity under elevated CO2 levels near geologic vents.

  3. De novo transcriptome assembly and analysis of differential gene expression in response to drought in European beech.

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    Markus Müller

    Full Text Available Despite the ecological and economic importance of European beech (Fagus sylvatica L. genomic resources of this species are still limited. This hampers an understanding of the molecular basis of adaptation to stress. Since beech will most likely be threatened by the consequences of climate change, an understanding of adaptive processes to climate change-related drought stress is of major importance. Here, we used RNA-seq to provide the first drought stress-related transcriptome of beech. In a drought stress trial with beech saplings, 50 samples were taken for RNA extraction at five points in time during a soil desiccation experiment. De novo transcriptome assembly and analysis of differential gene expression revealed 44,335 contigs, and 662 differentially expressed genes between the stress and normally watered control group. Gene expression was specific to the different time points, and only five genes were significantly differentially expressed between the stress and control group on all five sampling days. GO term enrichment showed that mostly genes involved in lipid- and homeostasis-related processes were upregulated, whereas genes involved in oxidative stress response were downregulated in the stressed seedlings. This study gives first insights into the genomic drought stress response of European beech, and provides new genetic resources for adaptation research in this species.

  4. Structures of Bordered Pits Potentially Contributing to Isolation of a Refilled Vessel from Negative Xylem Pressure in Stems of Morus australis Poir.: Testing of the Pit Membrane Osmosis and Pit Valve Hypotheses.

    Science.gov (United States)

    Ooeda, Hiroki; Terashima, Ichiro; Taneda, Haruhiko

    2017-02-01

    Two hypotheses have been proposed to explain the mechanism preventing the refilling vessel water from being drained to the neighboring functional vessels under negative pressure. The pit membrane osmosis hypothesis proposes that the xylem parenchyma cells release polysaccharides that are impermeable to the intervessel pit membranes into the refilling vessel; this osmotically counteracts the negative pressure, thereby allowing the vessel to refill. The pit valve hypothesis proposes that gas trapped within intervessel bordered pits isolates the refilling vessel water from the surrounding functional vessels. Here, using the single-vessel method, we assessed these hypotheses in shoots of mulberry (Morus australis Poir.). First, we confirmed the occurrence of xylem refilling under negative pressure in the potted mulberry saplings. To examine the pit membrane osmosis hypothesis, we estimated the semi-permeability of pit membranes for molecules of various sizes and found that the pit membranes were not semi-permeable to polyethylene glycol of molecular mass osmosis mechanism in mulberry would be unrealistically large. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. Effects of Land-Use Change on Under Storey Species Composition and Distribution in a Tropical Rainforest

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    Anthony Ifechukwude ODIWE

    2012-02-01

    Full Text Available The forest lands conversion into tree crops plantations plays a major role in the loss of biodiversity. Therefore, understanding the impacts of land-use change on species diversity is very critical for ecosystem functioning and stability. This study was carried out to evaluate the effect of land-use changes on under storey species diversity in the Theobroma cacao and Citrus sinensis plantations. Two, 25 m 25 m plots were sampled in each plantation and a nearby undisturbed secondary rainforest for comparison. The diameters (dbh-1.3 m of all trees at breast height >10 cm were measured in each plot. Five line transect were systematically laid and a quadrat of 50 cm 50 cm placed at every 1 m point to identify the under storey species (herbaceous, shrubs, tree saplings and climbers present in each plot. Percentage canopy, species diversity using Shannon-Wiener, Simpsons index and Evenness were determined, while species similarity was determined using the Jaccards similarity index. Results indicate that woody basal area and stem density in Theobroma cacao were significantly (P

  6. Needle removal by pine sawfly larvae increases branch-level VOC emissions and reduces below-ground emissions of Scots pine.

    Science.gov (United States)

    Ghimire, Rajendra P; Markkanen, Juha M; Kivimäenpää, Minna; Lyytikäinen-Saarenmaa, Päivi; Holopainen, Jarmo K

    2013-05-07

    Climate warming is expected to increase the frequency of insect outbreaks in Boreal conifer forests. We evaluated how needle removal by the larvae of two diprionid sawfly species affects the composition and quantity of VOC emissions from Pinus sylvestris L. saplings. Feeding damage significantly increased the rate of localized VOC emissions from the damaged branch. The emissions of total monoterpenes (MTs) were dominating (96-98% of total VOCs) and increased by14-fold in Neodiprion sertifer-damaged branches and by 16-fold in Diprion pini-damaged branches compared to intact branches. Emissions of δ-3-carene, α-pinene, sabinene, and β-phellandrene were most responsive. Feeding damage by N. sertifer larvae increased the emission rates of total sesquiterpenes by 7-fold (4% of total VOCs) and total green leaf volatiles by 13-fold (VOCs). The VOC emissions from N. sertifer larvae constituted nearly 25% of the total branch emissions. N. sertifer feeding in the lower branches induced 4-fold increase in MT emissions in the top crown. Defoliation of Scots pine by D. pini significantly reduced the below-ground emissions of total MTs by approximately 80%. We conclude that defoliators could significantly increase total VOC emissions from the Scots pine canopy including MT emissions from resin storing sawfly larvae.

  7. Compensatory mechanisms mitigate the effect of warming and drought on wood formation.

    Science.gov (United States)

    Balducci, Lorena; Cuny, Henri E; Rathgeber, Cyrille B K; Deslauriers, Annie; Giovannelli, Alessio; Rossi, Sergio

    2016-06-01

    Because of global warming, high-latitude ecosystems are expected to experience increases in temperature and drought events. Wood formation will have to adjust to these new climatic constraints to maintain tree mechanical stability and long-distance water transport. The aim of this study is to understand the dynamic processes involved in wood formation under warming and drought. Xylogenesis, gas exchange, water relations and wood anatomy of black spruce [Picea mariana (Mill.) B.S.P.] saplings were monitored during a greenhouse experiment where temperature was increased during daytime or night-time (+6 °C) combined with a drought period. The kinetics of tracheid development expressed as rate and duration of the xylogenesis sub-processes were quantified using generalized additive models. Drought and warming had a strong influence on cell production, but little effect on wood anatomy. The increase in cell production rate under warmer temperatures, and especially during the night-time warming at the end of the growing season, resulted in wider tree-rings. However, the strong compensation between rates and durations of cell differentiation processes mitigates warming and drought effects on tree-ring structure. Our results allowed quantification of how wood formation kinetics is regulated when water and heat stress increase, allowing trees to adapt to future environmental conditions. © 2015 John Wiley & Sons Ltd.

  8. Carbon dioxide fixation in green plants; Shokubutsu no tansan gas kotei ni kansuru kiso kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, S. [Kansai Electric Power Co. Inc., Osaka (Japan); Kiyota, M. [University of Osaka Prefecture, Osaka (Japan); Nishimura, M. [Kansai Tech Co., Osaka (Japan)

    1997-09-30

    Concerning the effects of carbon dioxide whose level of concentration is on the rise, the short-term effect that works on the amount of exchanged gas and the long-term effect that works on the growth of green plants are studied by use of several kinds of green plants. Changes in the carbon dioxide absorption rate (photosynthetic rate) in saplings in the wake of a rise in carbon dioxide concentration are studied, and it is found that a rise in carbon dioxide concentration results in an increase in the photosynthetic rate and that the rate rises with an increase in the intensity of light. The effect of temperature is stronger when concentration is higher, with the temperature suitable for photosynthesis moving toward the high-temperature side. Growth is investigated of seedlings of Acacia mangium two years after transplantation, and then it is found that seedlings in the 1000ppm carbon dioxide section are greater by 20% in height and by 30% in trunk diameter than those in the 350ppm carbon dioxide section. In addition, the total dry matter weight is heavier by 82%. As for dry matter accumulation, there are noticeable amounts in the branches, trunks, and roots, while there is but a 15% increase in the leaf area. Leaves fall early in the high carbon dioxide environment, and this is supposedly the cause for a slowdown in the rate of the increase of photosynthesis. 6 refs., 7 figs., 2 tabs.

  9. Agroforestry-based management of salt-affected croplands in irrigated agricultural landscape in Uzbekistan

    Science.gov (United States)

    Khamzina, Asia; Kumar, Navneet; Heng, Lee

    2017-04-01

    In the lower Amu Darya River Basin, the decades of intensive irrigation led to elevated groundwater tables, resulting in ubiquitous soil salinization and adverse impact on crop production. Field-scale afforestation trials and farm-scale economic analyses in the Khorezm region have determined that afforestation can be an environmentally and financially attractive land-use option for degraded croplands because it combines a diversified agricultural production, carbon sequestration, an improved soil health and minimizes the use of irrigation water. We examined prospects for upscaling afforestation activity for regional land-use planning considering prevailing constraints in irrigated agriculture landscape. Assessment of salinity-induced cropland productivity decline using satellite imagery of multiple spatial and temporal resolution revealed that 18-38% of the marginally productive or abandoned cropland might be considered for conversion to agroforestry. Furthermore, a regional-scale water balance suggests that most of these marginal croplands are characterized by sufficient surface water supplies for irrigating the newly planted saplings, before they are able to rely on the groundwater alone. However, the 10-year monitoring of soil salt dynamics in the afforestation trials reveals increasing salinity levels due to the salt exclusion from the root water uptake by the trees. Further study focuses on enhancing long-term sustainability of afforestation as a management option for highly saline lands by examining salt tolerance of candidate species using 13C isotopic signature as the indicator of water and salt stress, salt leaching needs and implications for regional scale planning.

  10. Physiological responses of the tropical tree Tibouchina pulchra Cogn under the influence of combustion of crude oil and natural gas at an oil refinery.

    Science.gov (United States)

    Silva, Daiane T; Moraes, Regina M

    2013-04-01

    A refinery located on the slopes of a mountain range in the city of Cubatão (SE-Brazil) is the main source of sulfur dioxide (SO(2)) in the region. For this reason, the refinery replaced a system in which energy was produced from crude oil combustion in boilers with a system of energy and vapor co-generation in a thermoelectric power plant fueled by natural gas. The aim of this study was to investigate the responses of Tibouchina pulchra to the fuel switching. Saplings planted in pots were distributed throughout monitoring sites around the polluting source (sites I, II, III and IV) and in a site (V) far from emissions. Changes on the plants responses occur along the three fuel switching phases. During the last phase, increased carbon assimilation (Asat) and decreased stomatal conductance (gs) were observed in plants growing in sites II and III; as a consequence, intrinsic water use efficiency (iWUE) increased. However, the increase in Asat did not promote growth increase suggesting that changes at the refinery did not result in better air quality, but only in a change in the main contaminants. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Bamboo thickets alter the demographic structure of Euterpe edulis population: A keystone, threatened palm species of the Atlantic forest

    Science.gov (United States)

    Rother, Débora Cristina; Rodrigues, Ricardo Ribeiro; Pizo, Marco Aurélio

    2016-01-01

    The rapid spread of bamboos can strongly affect forest structure by interfering plant regeneration and reducing local biodiversity. Considering that bamboos exert a negative influence on the plant community, our main goal was to investigate how this influence manifests at the population level. We compared the demographic structure of the threatened palm Euterpe edulis between bamboo and non-bamboo dominated patches within the Atlantic forest. In the study site, the native bamboo Guadua tagoara has created a marked patchiness and heterogeneity in the vegetation. Plots were set up randomly in bamboo and non-bamboo patches and the heights of all E. edulis individuals were measured. Data from canopy openness and litter depth were collected for both patches. Greater number of E. edulis was recorded in bamboo patches. However, frequency distribution of the height classes differed between patches revealing a predominance of seedling and sapling I classes in bamboo patches, in comparison to a more evenly distribution of height classes in non-bamboo patches. The canopy in bamboo patches was more open and the litter depth was thicker. Our analyses evidenced G. tagoara is functioning as a demographic bottleneck of natural population of E. edulis by arresting its later stages of regeneration and in high densities that bamboos may limit recruitment of this palm species.

  12. Effects of frugivore impoverishment and seed predators on the recruitment of a keystone palm

    Science.gov (United States)

    Fadini, Rodrigo F.; Fleury, Marina; Donatti, Camila I.; Galetti, Mauro

    2009-03-01

    Many plant species are threatened as a result of extinction of their large-bodied frugivores all over the world. Additionally, introduced herbivores and seed predators may cause severe pressure on early stages of plant recruitment. We studied the seed dispersal and seed predation of the keystone palm Euterpe edulis on a land-bridge island with a highly impoverished frugivore fauna and overabundant seed predators, and in a continuous Atlantic forest in Brazil. While the diversity of avian seed dispersers and predators was higher on the mainland, the abundance of seed dispersers was 4-fold higher on the island. Turdus flavipes was responsible for 72% and 96% of seeds removed in the island and mainland, respectively. However, the higher density of T. flaviceps on the island did not result in higher seed removal. In fact, seed removal rate was 1.7 times lower there than on the mainland, probably due to the aggressive behavior of the major seed disperser who defend palm fruits. Seed predation, on the other hand, was markedly higher on the island, where nearly 100% of seeds were preyed upon, but only 0.3% on the mainland. As a consequence of higher seed predation the population of E. edulis has few numbers of seedlings and saplings on the island. Therefore, management of the seed predator populations on the island is a key priority for recovering the natural population of this keystone palm and the frugivores that depend on its fruits.

  13. Keanekaragaman Tanaman Pekarangan dan Pemanfaatannya untuk Mendukung Ketahanan Pangan Kecamatan Wakorumba Selatan

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    Feriatin

    2017-08-01

    Full Text Available This study aimed to determine the type composition, vegetation structure, and the patterns of utilization to support food security in the sub district of South Wakorumba. This study employed a quadrat method. The results of this research show that the composition of plant species in gardens in South Wakorumba sub district was comprised of 25 families from 44 species of plants. For plants vegetation structure the highest of importance value for trees of the class was indicated by coconut (Cocos nucifera L. species. Whereas the lowest value was indicated by water apple (Eugenia aquea Burm. F species. For of poles, the highest of importance value was indicated by chocolate (Theobroma cacao L. species. Whereas the lowest value was by Jamaica cashew (Syzygium malacensis species. The class of saplings highest value was indicated by papaya (Carica papaya L. species. whereas the lowest was indicated by tamarind (Tamarindus indica L. species. For of seedling the highest of importance value was indicated by coconut (Cocos nucifera L. species. Whereas the lowest of importance value was indicated by rambutan (Nephelium lappaceum L. species. The pattern of utilization of garden plants by the villagers of Wakorumba Sub District is as follows: as a source of carbohydrate (18.18%, proteins (11.36%, vitamins (45.45%, minerals (22.73%, and fat (2.27%

  14. Structural analysis of tree trunks and branches: tapered cantilever beams subject to large deflections under complex loading.

    Science.gov (United States)

    Morgan, J; Cannell, M G

    1987-12-01

    The dimensions, deflections and support costs of tree trunks and branches can be deduced using the structural theory for cantilever beams. However, elementary theory applies only as long as deflections are small, and complex analytical solutions are required to account for complex taper and patterns of loading. This paper describes a method that copes with large deflections, any patterns of taper, and any patterns of distributed loading, point loading or externally applied bending moments. A beam is considered to be composed of a series of short segments, such that each has only a small deflection, and each can have specified dimensions, Young's modulus and loading. The transport matrix method of structural analysis is used to determine the end conditions of each segment and of the whole beam. The method is verified by comparing predicted deflections with deflections (a) calculated using an analytical solution by Bisshopp and Drucker (1945), (b) calculated and measured for sapling tree trunks by Leiser and Kemper (1968), and (c) measured on tapered and untapered plastic rods.

  15. Responses toward a trapped animal by wild bonobos at Wamba.

    Science.gov (United States)

    Hayashi, Misato; Ohashi, Gaku; Ryu, Heung Jin

    2012-07-01

    Chimpanzees and bonobos are the closest living relatives of humans and diverged relatively recently in their phylogenetic history. However, a number of reports have suggested behavioral discrepancies between the two Pan species, such as more cooperative and tolerant social interaction and poorer tool-using repertoires in bonobos. Concerning hunting behavior and meat consumption, recent studies from the field have confirmed both behaviors not only in chimpanzees but also in bonobos. The present study reports an encounter by wild bonobos at Wamba with a duiker trapped in a snare. Bonobos interacted with the live duiker for about 10 min but did not eventually kill the animal. They showed fear responses when the duiker moved and exhibited behaviors related to anxiety and stress such as branch-drag displays and self-scratching. Although bonobos manipulated nearby saplings and parts of the snare, they did not use detached objects to make indirect contact with the duiker. Juveniles and adults of both sexes engaged in active interactions with the trapped duiker. Overall, bonobos' behavioral responses indicated species-specific cognitive characteristics largely different from those of chimpanzees.

  16. Structure and Regeneration Patterns of Pinus nigra subsp. salzmannii Natural Forests: A Basic Knowledge for Adaptive Management in a Changing Climate

    Directory of Open Access Journals (Sweden)

    Pedro A. Tíscar

    2011-12-01

    Full Text Available Since climate change projections contain many uncertainties and are normally unable to predict the direction and magnitude of change at the small scale needed by forest managers, some understanding about the functioning of the target forest should be obtained before a robust management strategy can be applied. Structure and regeneration patterns are related to key ecosystem processes which, on the other hand, can be modified by silvicultural treatments. In this research, the structure and recruitment dynamics of two stands with different histories of management were investigated in the southern limit of the range of Pinus nigra subsp. salzmannii (Southeast Spain. We described forest structure and facilitation effects by forest canopies and nurse shrubs, and quantified the processes affecting each stage of regeneration (dispersed seed, first year seedling and second year seedling in different microhabitats. Forest structure was more complex in the stand scarcely influenced by human activities. Juniperus communis shrubs seemed to facilitate the establishment of tree saplings. Most seedlings died of desiccation during their first summer. At best, 190 out of 10,000 emerged seedlings survived the first summer. In light of these results, the possibilities of applying close-to-nature forestry in the study forests and other aspects of silviculture under a frame of adaptive forest management are discussed.

  17. Biomass Accumulation and Net Primary Production during the Early Stage of Secondary Succession after a Severe Forest Disturbance in Northern Japan

    Directory of Open Access Journals (Sweden)

    Tomotsugu Yazaki

    2016-11-01

    Full Text Available Quantitative evaluations of biomass accumulation after disturbances in forests are crucially important for elucidating and predicting forest carbon dynamics in order to understand the carbon sink/source activities. During early secondary succession, understory vegetation often affects sapling growth. However, reports on biomass recovery in naturally-regenerating sites are limited in Japan. Therefore, we traced annual or biennial changes in plant species, biomass, and net primary production (NPP in a naturally regenerating site in Japan after windthrow and salvage-logging plantation for nine years. The catastrophic disturbance depleted the aboveground biomass (AGB from 90.6 to 2.7 Mg·ha−1, changing understory dominant species from Dryopteris spp. to Rubus idaeus. The mean understory AGB recovered to 4.7 Mg·ha−1 in seven years with the dominant species changing to invasive Solidago gigantea. Subsequently, patches of deciduous trees (mainly Betula spp. recovered whereas the understory AGB decreased. Mean understory NPP increased to 272 g·C·m−2·year−1 within seven years after the disturbance, but decreased thereafter to 189 g·C·m−2·year−1. Total NPP stagnated despite increasing overstory NPP. The biomass accumulation is similar to that of naturally regenerating sites without increase of trees in boreal and temperate regions. Dense ground vegetation and low water and nutrient availability of the soil in the study site restrict the recovery of canopy-forming trees and eventually influence the biomass accumulation.

  18. Response of tropical trees to sulphur dioxide stress and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Vartshney, C.K.; Mitra, I. [Jawaharlal Nehru University, New Delhi (India). School of Environmental Sciences

    1995-12-31

    Ethylene emission, ascorbic acid content, peroxidase and superoxide dismutase activity were measured in four tropical tree species. Six month old saplings of Morus alba Linn., Azadirachta indica A.Juss., Melia-azadirach Linn. and Syzgium jambolina Lamk, were exposed to 0.5 ppm SO{sub 2} for four hours for six consecutive days. Recovery from SO{sub 2} stress was followed for twelve days after termination of the fumigation. SO{sub 2} induced foliar ethylene emission increased during fumigation but declined following termination of fumigation. SO{sub 2} fumigation enhanced the activities of superoxide dismutase and peroxidase in all four species. Their activities, however, declined on withdrawal of SO{sub 2} stress. Ascorbic acid content decreased due to SO{sub 2} stress but exhibited recovery on termination of fumigation. The response of the four plant species was widely different both during the fumigation period and during post-fumigation recovery regime. 26 refs., 3 figs., 2 tabs.

  19. Biological invasion of Pinus ponderosa and Pinus contorta: case study of a forest plantation in Northwestern Patagonia; Invasion biologica de Pinus ponderosa y Pinus contorta: estudio de caso de una plantacion en la Patagonia noroccidental

    Energy Technology Data Exchange (ETDEWEB)

    Dezzotti, A.; Sbrancia, R.; Mortoro, A.; Monte, C.

    2009-07-01

    In the Southern Hemisphere, Pinus species from plantations can bring about processes of biological invasion that cause significant and permanent changes on the structure and functioning of surrounding natural ecosystems. The invasive character of Pinus ponderosa (P) and Pinus contorta (C) was examined for a 20-year old plantation located in the Alicura Forest Station (40 degree centigrade 40' S and 71 degree centigrade 00' W), through the analysis of abundance, age and spatial structures, and dispersal of natural regeneration. Seedlings and saplings were located largely within the plantation boundaries, and exhibited a density of 6.9 ind / ha (41 % for P and 59 % for C), a clustered spatial pattern with clumps dispersed not randomly, and a mean dispersal rate of 9.5 m / yr for P. ponderosa and 5.4 m / yr for P. contorta. Both species were invading the adjacent area, according to technical criteria based on ecological responses. However, regeneration niche is strongly hindering tree establishment and dispersal, probably due to high plant cover, presence of vertic soils, and absence of ectomycorrhizal fungi. These results can contribute to predict the capability of P. contorta and P. ponderosa to become invasive, in order to maximize the positive balance of forestry based on these species in northwestern Patagonia. (Author) 50 refs.

  20. Ecological study on mangrove forest in East Coast of North Sumatra

    Directory of Open Access Journals (Sweden)

    ONRIZAL

    2008-01-01

    Full Text Available Ecological studies on mangrove forest in East Coast of North Sumatra have been carried out with field work in transect method and laboratory analyses. This study would be covered on floristic composition, abrasion, green belt, soil properties, and water quality of mangroves. Land system map and landsat TM imagery (year 1996 coverage as main material in this study were used and overlay to determine training area. Based on vegetation inventory found that 20 mangrove species and by vegetation analyses, we known that Avicennia marina was as dominant tree species of seedling and sapling stage. Tree stage was not found in the area, yet. Environment properties of the mangrove area were suitable for mangrove growth and rehabilitation with the exception of pyrite content in the mangrove soil. Average of mangrove green belt was 25 m with range from 10 to 80 m in KJP (Kajapah land system and 30 m with range 10 to 50 m in PTG (Putting land system. Abrasion rate in the area was very high, i.e. 6 m per year in KJP land system, and 10 m per year in PTG land system.

  1. Effects of different soil ameliorants on karee trees (Searsia lancea) growing on mine tailings dump soil-part I: pot trials.

    Science.gov (United States)

    Lange, Christian A; Kotte, Karsten; Smit, Martin; van Deventer, Peter W; van Rensburg, Leon

    2012-10-01

    Rehabilitation of mine tailings dams is often a challenge due to a lack of nutrients and a poor humus reservoir prevailing in tailings soils. This is especially true for establishing longer lived species such as trees. For these reasons the effects of different soil ameliorants (woodchips compost, vermicompost, mature sewage sludge), added to the root system of Karee (Searsia lancea) saplings were tested in pot trials. Those pots were filled with platinum and gold tailings substrate as well as red clay soil, respectively. For three months plants remained in a greenhouse and were subsequently moved to a test field outside. Throughout the test period regular chl a fluorescence measurements were taken and subjected to JIP-test quantifying changes in photosynthetic vitality status. Additionally, growth measurements and one-off leaf analysis were carried out. Test plants growing on mine tailings experienced an up to 35% higher average photosynthetic vitality (PI(ABS)) and improved nutrient supply, when treated with mature sewage sludge. Consequently, sewage sludge treated plants showed a higher biomass build-up rate and an up to 55% higher diameter growth, compared to control. In summary the experiments present a low cost alternative for reforestation enterprises on platinum and gold tailings dams in South Africa.

  2. DIVERSITY OF PLANT COMMUNITIES IN SECONDARY SUCCESSION OF IMPERATA GRASSLANDS IN SAMBOJA LESTARI, EAST KALIMANTAN, INDONESIA

    Directory of Open Access Journals (Sweden)

    Ishak Yassir

    2016-06-01

    Full Text Available Regeneration of  Imperata grassland areas is becoming increasingly important, both to create new secondary forest and to recover the original biodiversity. The diversity of  plant communities in secondary succession of  Imperata grasslands was studied using 45 subplots of  9 linear transects (10 m x 100 m. Data was collected and all stems over 10 cm dbh were identified, the Importance Values Index (IVI for all trees were calculated, saplings and seedlings were counted  and analysed, and soil samples were taken and analysed. Results showed that  after more than 10 years of  regeneration, 65 families were encountered consisting of  164 species, which were dominated by Vernonia arborea Buch.-Ham, Vitex pinnata L., Macaranga gigantea (Reichb.f. & Zoll. Muell.Arg., Symplocos crassipes C.B. Clarke, Artocarpus odoratissimus Miq., and Bridelia glauca Blume. The effects of  regeneration, from Imperata grassland to secondary forest, on soil were the strongest in the A-horizon where an increase in carbon, N content, and pH were observed. Our result shows that Imperata grasslands appear to be permanent because of  frequent fires and human interferences and so far few efforts have been made to promote sustainable rehabilitation. If  protected from fire and other disturbances, such as shifting cultivation, Imperata grassland will grow and develop into secondary forest.

  3. One Century of Treeline Change and Stability - Experiences from the Swedish Scandes

    Directory of Open Access Journals (Sweden)

    Leif Kullman

    2010-03-01

    Full Text Available This paper elaborates and visualizes processes recorded in a recent regional and multi-site study of elevational treeline dynamics during the period 1915 to 2007 in the Swedish Scandes. The purpose is to give a concrete face of the landscape transformation which is associated with the recorded treeline shifts. The main focus is on stand-level structure of past and present treelines and the advance zones, where climate change elicited responses by Betula pubescens ssp. czerepanovii, Picea abies and Pinus sylvestris. All species shifted their treelines upslope by a maximum of c. 200 m in elevation. Most sites, however, manifested changes of smaller magnitudes. This relates to topoclimatic constraints which decouple treeline performance from the macroclimate. The general character of sites which support large and small treeline shifts, respectively, are outlined. The spacing, age structure, growth rates of the tree advance zones are accounted for each of the concerned species. In temporal and spatial detail, the different tree species responded individualistically according to their specific ecologies. Current spread of young seedlings and saplings to increasingly higher elevations in the alpine tundra is particularly highlighted as it may represent the forefront of future treeline advance. It is argued that the current evolution of the treeline ecotone represents a fundamental, although not necessarily entirely unique, reversal of the long-term (Holocene trend of neoglacial treeline descent.

  4. Climate Changes and Their Impact on Agricultural Market Systems: Examples from Nepal

    Directory of Open Access Journals (Sweden)

    Andrea Karin Barrueto

    2017-11-01

    Full Text Available Global climate models foresee changes in temperature and precipitation regimes that shift regional climate zones and influence the viability of agricultural market systems. Understanding the influence of climate change on the different sub-sectors and functions of a market system is crucial to increasing the systems’ climate resilience and to ensuring the long-term viability of the sectors. Our research applies a new approach to climate change analysis to better understand the influence of climate change on each step of an agricultural market system—on its core (processing units, storage facilities and sales and support functions (sapling supply, research, insurance and agricultural policy. We use spatial climate analyses to investigate current and projected changes in climate for different regions in Nepal. We then analyse the risks and vulnerabilities of the sub-sectors banana, charcoal, coffee, macadamia, orange, vegetables and walnut. Our results show that temperatures and precipitation levels will change differently depending on the climatic regions, and that climate change elicits different responses from the market functions both between and within each of the different sub-sectors. We conclude that climate-related interventions in market systems must account for each different market function’s specific response and exposure to climate change, in order to select adaptation measures that ensure long-term climate resilience.

  5. DIVERSITY OF FEED PLANTS OF SUMATRAN ELEPHANT HABITATS (ELEPHAS MAXIMUS SUMATRANUS IN JANTHO PINUS NATURE RESERVE, ACEH BESAR DISTRICT

    Directory of Open Access Journals (Sweden)

    Ma’rifatin Zahrah

    2016-03-01

    Full Text Available This research conducted to identify the kinds of feed plants sumatran elephant which is the main component of elephant habitats .The purpose of this research was to obtain data about kinds of feed plants sumatran elephant and analyzes the species diversity. The study conducted with analysis vegetation use of systematic sampling methods at any community different vegetation .The research results recorded there are 75 species of  feed plants  from 269 species of plants found , which means 28%  plants in the study locations is a source of feed for sumatran elephants. The data was obtained show that the number of species to spread of  feed plants of elephant more on a community of  I , a number of 36 species of all level vegetation began to the seedling, sapling, pole and tree; while community II and III each 30 and 23 species . Community IV and V had the same number of  feed plants species, a number of 31 species . Based on the analysis of the diversity of species to feed plants  of elephant, shows that community III have index the diversity of species ( H = 4,53; Hmax = 5,17 higher than other locations.

  6. Development of Northern White-Cedar Regeneration Following Partial Cutting, with and without Deer Browsing

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    Catherine Larouche

    2015-02-01

    Full Text Available Northern white-cedar (Thuja occidentalis L. is an important commercial species with a high wildlife value, both as a food source and habitat for many bird and mammal species. Concerns have been expressed about its decreasing abundance across its range, and especially in mixedwood stands, where it has to compete with several other species and can suffer from heavy browsing. In this study, we quantified the development of natural northern white-cedar seedlings and saplings under various partial cutting regimes, with and without white-tailed deer (Odocoileus virgianus Zimmerman browsing, in three selected sites in Quebec (Canada and in Maine (USA. Our data show that northern white-cedar regeneration was present in all studied stands, but that only a few stems were taller than 30 cm on the two sites with high densities of deer. In the absence of heavy browsing, stems reached a height of 30 cm in 11 years, and 130 cm in 28 years. Height growth of northern white-cedar regeneration increased with canopy light transmittance, while ground-level diameter increment increased after partial cutting. This suggests that partial cutting can be used in mixedwood stands to release natural northern white-cedar regeneration, but also that the recruitment of northern white-cedar seedlings to larger size classes constitutes a major challenge in stands subject to heavy deer browsing.

  7. Determination of terpenoid content in pine by organic solvent extraction and fast-GC analysis

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    Anne Elizabeth Harman-Ware

    2016-01-01

    Full Text Available Terpenoids, naturally occurring compounds derived from isoprene units present in pine oleoresin, are a valuable source of chemicals used in solvents, fragrances, flavors and have shown potential use as a biofuel. This paper describes a method to extract and analyze the terpenoids present in loblolly pine saplings and pine lighter wood. Various extraction solvents were tested over different times and temperatures. Samples were analyzed by pyrolysis-molecular beam mass spectrometry before and after extractions to monitor the extraction efficiency. The pyrolysis studies indicated that the optimal extraction method used a 1:1 hexane/acetone solvent system at 22°C for 1 h. Extracts from the hexane/acetone experiments were analyzed using a low thermal mass modular accelerated column heater for fast-GC/FID analysis. The most abundant terpenoids from the pine samples were quantified, using standard curves, and included the monoterpenes, α- and β- pinene, camphene and δ-carene. Sesquiterpenes analyzed included caryophyllene, humulene and α-bisabolene. Diterpenoid resin acids were quantified in derivatized extractions, including pimaric, isopimaric, levopimaric, palustric, dehydroabietic, abietic and neoabietic acids.

  8. Effects of topsoil treatments on afforestation in a dry Mediterranean climate (southern Spain)

    Science.gov (United States)

    Hueso-González, Paloma; Francisco Martínez-Murillo, Juan; Damian Ruiz-Sinoga, Jose

    2016-10-01

    Afforestation programs in semiarid areas are associated with a high level of sapling mortality. Therefore, the development of alternative low-cost and low-environmental-impact afforestation methods that ensure the survival of seedlings is crucial for improving the efficiency of Mediterranean forest management. This study assessed the effects of five types of soil amendments on the afforestation success (e.g., plant growth and survival) of a Mediterranean semiarid area. The amendments tested were (i) straw mulch; (ii) mulch containing chipped branches of Aleppo pine (Pinus halepensis L.); (iii) sheep manure compost; (iv) sewage sludge from a wastewater treatment plant; and (v) TerraCottem hydroabsorbent polymer. We hypothesized that in the context of dry Mediterranean climatic conditions, the use of organic amendments would enhance plant establishment and ensure successful afforestation. The results showed that afforestation success varied among the various soil amendment treatments in the experimental plots. The amendments had no effect on soil organic carbon, pH, or salinity, but the results indicated that the addition of mulch or hydroabsorbent polymer can reduce transplant stress by increasing the soil water available for plant growth throughout the hydrological year, and potentially improve the success of afforestation by reducing plant mortality.

  9. Establishing a long-term permanent plot in remnant forest of Cibodas Botanic Garden, West Java

    Directory of Open Access Journals (Sweden)

    ZAENAL MUTAQIEN

    2011-10-01

    Full Text Available Mutaqien Z, Zuhri M (2011 Establishing a long-term permanent plot in remnant forest of Cibodas Botanic Garden, West Java. Biodiversitas 12: 218-224. Cibodas Botanic Garden (CBG has unique characters; almost 10% of which is forested area adjacent to the natural forest of Mt. Gede Pangrango National Park. The area is a transition between natural forest and artificial habitat which mostly consists of exotic plant species. The permanent plot in CBG was established in 2007-2009. Two hundred and eighty four units of 10x10 square meters sub-plot were established in four locations, i.e. Wornojiwo, Kompos, Jalan Akar, and Lumut forest. Vegetation analyses were conducted for trees, saplings, shrubs, and herb species. The inventory found 137 species plants consisting of 74 tree species dominated by Villebrunea rubescens (Bl. Bl. and Ostodes paniculata Bl., 30 shrub species dominated by Strobilanthes hamiltoniana (Steud., 24 herb species dominated by Cyrtandra picta Bl., 6 fern species mainly consisted of Diplazium pallidum Moore, and 3 climber species dominated by Calamus reinwardtii Mart. In comparison with the natural forest of Mt. Gede Pangrango National Park, the CBG permanent plot showed a good representative of the vegetation of lower montane forest. A regular monitoring during the successive years is needed to maintain diversity, monitor forest dynamics and anticipate the spread of invasive plant from CBG.

  10. A difference gel electrophoresis study on thylakoids isolated from poplar leaves reveals a negative impact of ozone exposure on membrane proteins.

    Science.gov (United States)

    Bohler, Sacha; Sergeant, Kjell; Hoffmann, Lucien; Dizengremel, Pierre; Hausman, Jean-Francois; Renaut, Jenny; Jolivet, Yves

    2011-07-01

    Populus tremula L. x P. alba L. (Populus x canescens (Aiton) Smith), clone INRA 717-1-B4, saplings were subjected to 120 ppb ozone exposure for 28 days. Chloroplasts were isolated, and the membrane proteins, solubilized using the detergent 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC), were analyzed in a difference gel electrophoresis (DiGE) experiment comparing control versus ozone-exposed plants. Extrinsic photosystem (PS) proteins and adenosine triphosphatase (ATPase) subunits were detected to vary in abundance. The general trend was a decrease in abundance, except for ferredoxin-NADP(+) oxidoreductase (FNR), which increased after the first 7 days of exposure. The up-regulation of FNR would increase NAPDH production for reducing power and detoxification inside and outside of the chloroplast. Later on, FNR and a number of PS and ATPase subunits decrease in abundance. This could be the result of oxidative processes on chloroplast proteins but could also be a way to down-regulate photochemical reactions in response to an inhibition in Calvin cycle activity.

  11. Floristic, edaphic and structural characteristics of flooded and unflooded forests in the lower Rio Purús region of central Amazonia, Brazil

    Directory of Open Access Journals (Sweden)

    Haugaasen Torbjørn

    2006-01-01

    Full Text Available Despite a natural history interest in the early 1900s, relatively little ecological research has been carried out in the Rio Purús basin of central Amazonia, Brazil. Here we describe a new study area in the region of Lago Uauaçú with an emphasis on the climate, forest structure and composition, and soil characteristics between adjacent unflooded (terra firme and seasonally inundated forests; situated within both the white-water (várzea and black-water (igapó drainage systems that dominate the landscape. The climate was found to be typical of that of the central Amazon. Várzea forest soils had high concentrations of nutrients, while terra firme and igapó soils were comparatively nutrient-poor. Terra firme forests were the most floristically diverse forest type, whereas várzea was intermediate, and igapó the most species-poor. The Lecythidaceae was the most important family in terra firme while the Euphorbiaceae was the most important in both várzea and igapó. There were significant differences between forest types in terms of number of saplings, canopy cover and understorey density. In contrasting our results with other published information, we conclude that the Lago Uauaçú region consists of a typical central Amazonian forest macro-mosaic, but is a unique area with high conservation value due to the intimate juxtaposition of terra firme, várzea and igapó forests.

  12. Aleppo pine knot disease: histology of the knots, detection of causal agent and mode of transmission

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    ROBERTO CALAMASSI

    2008-07-01

    Full Text Available Knot disease of Aleppo pine (Pinus halepensis subsp. halepensis occurs in the western range of the host in the Mediterranean region. The disease, originally named Aleppo pine tuberculosis (from tubercle, i.e. knot by Petri in 1924, causes a hyperplastic growth on the twigs and small branches, with knots that initially are small, green and lignified, and expand to 5–6 cm diameter at maturity. These knots have been associated with various bacterial species. In this study, only one bacterium was isolated from Aleppo pine knots, and this bacterium was constantly associated with the pine weevil Pissodes castaneus. The hyperplastic growth started either in the cortex or in the xylem, while the knot was formed in the cortical parenchyma. Bacteria were grouped in zoogloeae in the intercellular spaces or inside lysigenous cavities. Bacterial microcolonies have also been observed in the parenchyma cells. Inoculation of two of the bacterial strains on healthy Aleppo pine twigs did not induce knot formation. Knots did however form when adults of P. castaneus were externally contaminated with the bacteria and were then allowed to feed on pine saplings. These latter knots contained the same bacterial isolate as that which had been used to contaminate the weevils. All the isolates examined were tentatively assigned to the genus Erwinia. As this bacterium seems to be the causal agent of Aleppo pine knot disease, its complete identification and characterisation is needed.

  13. Fine Root Abundance and Dynamics of Stone Pine (Pinus cembra) at the Alpine Treeline Is Not Impaired by Self-shading.

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    Kubisch, Petra; Leuschner, Christoph; Coners, Heinz; Gruber, Andreas; Hertel, Dietrich

    2017-01-01

    Low temperatures are crucial for the formation of the alpine treeline worldwide. Since soil temperature in the shade of tree canopies is lower than in open sites, it was assumed that self-shading may impair the trees' root growth performance. While experiments with tree saplings demonstrate root growth impairment at soil temperatures below 5-7°C, field studies exploring the soil temperature - root growth relationship at the treeline are missing. We recorded soil temperature and fine root abundance and dynamics in shaded and sun-exposed areas under canopies of isolated Pinus cembra trees at the alpine treeline. In contrast to the mentioned assumption, we found more fine root biomass and higher fine root growth in colder than in warmer soil areas. Moreover, colder areas showed higher fine root turnover and thus lower root lifespan than warmer places. We conclude that P. cembra balances enhanced fine root mortality in cold soils with higher fine root activity and by maintaining higher fine root biomass, most likely as a response to shortage in soil resource supply. The results from our study highlight the importance of in situ measurements on mature trees to understand the fine root response and carbon allocation pattern to the thermal growth conditions at the alpine treeline.

  14. Experimental evidence for herbivore limitation of the treeline.

    Science.gov (United States)

    Speed, James D M; Austrheim, Gunnar; Hester, Alison J; Mysterud, Atle

    2010-11-01

    The treeline ecotone divides forest from open alpine or arctic vegetation states. Treelines are generally perceived to be temperature limited. The role of herbivores in limiting the treeline is more controversial, as experimental evidence from relevant large scales is lacking. Here we quantify the impact of different experimentally controlled herbivore densities on the recruitment and survival of birch Betula pubescens tortuosa along an altitudinal gradient in the mountains of southern Norway. After eight years of summer grazing in large-scale enclosures at densities of 0, 25, and 80 sheep/km2, birch recruited within the whole altitudinal range of ungrazed enclosures, but recruitment was rarer in enclosures with low-density sheep and was largely limited to within the treeline in enclosures with high-density sheep. In contrast, the distribution of saplings (birch older than the experiment) did not differ between grazing treatments, suggesting that grazing sheep primarily limit the establishment of new tree recruits rather than decrease the survival of existing individuals. This study provides direct experimental evidence that herbivores can limit the treeline below its potential at the landscape scale and even at low herbivore densities in this climatic zone. Land use changes should thus be considered in addition to climatic changes as potential drivers of ecotone shifts.

  15. Cloning and characterization of isoprenyl diphosphate synthases with farnesyl diphosphate and geranylgeranyl diphosphate synthase activity from Norway spruce (Picea abies) and their relation to induced oleoresin formation.

    Science.gov (United States)

    Schmidt, Axel; Gershenzon, Jonathan

    2007-11-01

    The conifer Picea abies (Norway spruce) employs terpenoid-based oleoresins as part of its constitutive and induced defense responses to herbivores and pathogens. The isoprenyl diphosphate synthases are branch-point enzymes of terpenoid biosynthesis leading to the various terpene classes. We isolated three genes encoding isoprenyl diphosphate synthases from P. abies cDNA libraries prepared from the bark and wood of methyl jasmonate-treated saplings and screened via a homology-based PCR approach using degenerate primers. Enzyme assays of the purified recombinant proteins expressed in Escherichia coli demonstrated that one gene (PaIDS 4) encodes a farnesyl diphosphate synthase and the other two (PaIDS 5 and PaIDS 6) encode geranylgeranyl diphosphate synthases. The sequences have moderate similarity to those of farnesyl diphosphate and geranylgeranyl diphosphate synthases already known from plants, and the kinetic properties of the enzymes are not unlike those of other isoprenyl diphosphate synthases. Of the three genes, only PaIDS 5 displayed a significant increase in transcript level in response to methyl jasmonate spraying, suggesting its involvement in induced oleoresin biosynthesis.

  16. THE POTENTIAL OF VEGETATION SPECIES DIVERSITY FOR ECOTOROURISM DEVELOPMENT AT NATURE RESERVE OF PANJALU LAKE

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    Encep Rahman

    2017-06-01

    Full Text Available The Nature Reserve of Panjalu Lake is one of the oldest conservation area in Indonesia. As a conservation area, Panjalu Lake has different species of flora that are useful as germplasm conservation, science and education. This study aims to know the potential of vegetation species diversity for ecotourism development at Nature Reserve of Panjalu Lake. The inventory method used is line plot sampling with intensity 15 % in two paths of 500 m (adjusted according length of the area and 20 m width. Spacing between lines is 200 m and spacing between observation plot is 100 m. Within each path, 50 m x 20 m observation plots were established. The results showed that there are three species of seedlings with highest IVI, namely: Dysoxylum densiflorum Miq. (47.64 %, Calamus zollingerii (47.64 %, and Sterculia macrophylla Vent. (44.37 %. The four species at sapling stage with highest IVI are: Litsea cassiaefolia (114.29 %; Dysoxylum densiflorum Miq (57.14 %; Litsea sp. and Endiandra rubescens Miq (14.29 %. Three species at pole stage with highest IVI, namely: Dysoxylum densiflorum Miq. (143.04%; Litsea cassiaefolia (99.78 % and Artocarpus elasticus Reinw 9.53 %. Three species at tree stage with highest IVI, namely: Dysoxylum densiflorum Miq (147.924 %, Litsea cassiaefolia (68.753 %, and Eugenia fastigiata Miq ( 31.410 %.

  17. Influence of Tree Species Composition and Community Structure on Carbon Density in a Subtropical Forest.

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    Yanqiu Hu

    Full Text Available We assessed the impact of species composition and stand structure on the spatial variation of forest carbon density using data collected from a 4-ha plot in a subtropical forest in southern China. We found that 1 forest biomass carbon density significantly differed among communities, reflecting a significant effect of community structure and species composition on carbon accumulation; 2 soil organic carbon density increased whereas stand biomass carbon density decreased across communities, indicating that different mechanisms might account for the accumulation of stand biomass carbon and soil organic carbon in the subtropical forest; and 3 a small number of tree individuals of the medium- and large-diameter class contributed predominantly to biomass carbon accumulation in the community, whereas a large number of seedlings and saplings were responsible for a small proportion of the total forest carbon stock. These findings demonstrate that both biomass carbon and soil carbon density in the subtropical forest are sensitive to species composition and community structure, and that heterogeneity in species composition and stand structure should be taken into account to ensure accurate forest carbon accounting.

  18. Sap flow measurements of Ceriops tagal and Rhizophora mucronata mangrove trees by deuterium tracing and lysimetry.

    Science.gov (United States)

    Lambs, Luc; Saenger, Anaïs

    2011-10-15

    Mangrove forest trees grow in severe conditions such as diurnal submersion and high salinity surface and subsurface waters. This study focuses on two species on Mayotte Island, i.e. Ceriops tagal and Rhizophora mucronata, living in the middle range of the coastal mangrove. The seedlings of these trees were planted in a tropical greenhouse with an original pump system built to reproduce the natural tidal effect. The water used by these saplings, in two contrasted salinity conditions, was measured by lysimetry. For adult species, the trees' water consumption was measured on the field side after being injected with heavy water (D(2)O). Our work shows that this isotopic technique also works in saline conditions, and a water consumption of around 1 ± 0.2 L per day and per centimeter of diameter was found. These values are discussed as follows: the techniques used, the distinctive features of the mangrove trees, and other factors affecting the water absorption. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Sampling design and required sample size for evaluating contamination levels of 137Cs in Japanese fir needles in a mixed deciduous forest stand in Fukushima, Japan.

    Science.gov (United States)

    Oba, Yurika; Yamada, Toshihiro

    2017-05-01

    We estimated the sample size (the number of samples) required to evaluate the concentration of radiocesium (137Cs) in Japanese fir (Abies firma Sieb. & Zucc.), 5 years after the outbreak of the Fukushima Daiichi Nuclear Power Plant accident. We investigated the spatial structure of the contamination levels in this species growing in a mixed deciduous broadleaf and evergreen coniferous forest stand. We sampled 40 saplings with a tree height of 150 cm-250 cm in a Fukushima forest community. The results showed that: (1) there was no correlation between the 137Cs concentration in needles and soil, and (2) the difference in the spatial distribution pattern of 137Cs concentration between needles and soil suggest that the contribution of root uptake to 137Cs in new needles of this species may be minor in the 5 years after the radionuclides were released into the atmosphere. The concentration of 137Cs in needles showed a strong positive spatial autocorrelation in the distance class from 0 to 2.5 m, suggesting that the statistical analysis of data should consider spatial autocorrelation in the case of an assessment of the radioactive contamination of forest trees. According to our sample size analysis, a sample size of seven trees was required to determine the mean contamination level within an error in the means of no more than 10%. This required sample size may be feasible for most sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Biogeographic distributions of neotropical trees reflect their directly measured drought tolerances.

    Science.gov (United States)

    Esquivel-Muelbert, Adriane; Galbraith, David; Dexter, Kyle G; Baker, Timothy R; Lewis, Simon L; Meir, Patrick; Rowland, Lucy; Costa, Antonio Carlos Lola da; Nepstad, Daniel; Phillips, Oliver L

    2017-08-21

    High levels of species diversity hamper current understanding of how tropical forests may respond to environmental change. In the tropics, water availability is a leading driver of the diversity and distribution of tree species, suggesting that many tropical taxa may be physiologically incapable of tolerating dry conditions, and that their distributions along moisture gradients can be used to predict their drought tolerance. While this hypothesis has been explored at local and regional scales, large continental-scale tests are lacking. We investigate whether the relationship between drought-induced mortality and distributions holds continentally by relating experimental and observational data of drought-induced mortality across the Neotropics to the large-scale bioclimatic distributions of 115 tree genera. Across the different experiments, genera affiliated to wetter climatic regimes show higher drought-induced mortality than dry-affiliated ones, even after controlling for phylogenetic relationships. This pattern is stronger for adult trees than for saplings or seedlings, suggesting that the environmental filters exerted by drought impact adult tree survival most strongly. Overall, our analysis of experimental, observational, and bioclimatic data across neotropical forests suggests that increasing moisture-stress is indeed likely to drive significant changes in floristic composition.

  1. Simultaneous induction of jasmonic acid and disease-responsive genes signifies tolerance of American elm to Dutch elm disease

    Science.gov (United States)

    Sherif , S. M.; Shukla, M. R.; Murch, S. J.; Bernier, L.; Saxena, P. K.

    2016-01-01

    Dutch elm disease (DED), caused by three fungal species in the genus Ophiostoma, is the most devastating disease of both native European and North American elm trees. Although many tolerant cultivars have been identified and released, the tolerance mechanisms are not well understood and true resistance has not yet been achieved. Here we show that the expression of disease-responsive genes in reactions leading to tolerance or susceptibility is significantly differentiated within the first 144 hours post-inoculation (hpi). Analysis of the levels of endogenous plant defense molecules such as jasmonic acid (JA) and salicylic acid (SA) in tolerant and susceptible American elm saplings suggested SA and methyl-jasmonate as potential defense response elicitors, which was further confirmed by field observations. However, the tolerant phenotype can be best characterized by a concurrent induction of JA and disease-responsive genes at 96 hpi. Molecular investigations indicated that the expression of fungal genes (i.e. cerato ulmin) was also modulated by endogenous SA and JA and this response was unique among aggressive and non-aggressive fungal strains. The present study not only provides better understanding of tolerance mechanisms to DED, but also represents a first, verified template for examining simultaneous transcriptomic changes during American elm-fungus interactions. PMID:26902398

  2. Native flora rescue program: GASENE project case study

    Energy Technology Data Exchange (ETDEWEB)

    Serricchio, Claudio; Caldas, Flaviana V. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Akahori, Lisa [Telsan, Rio de Janeiro, RJ (Brazil); Jacomelli Junior, Jose Almir [AGF Engenharia, Araucaria, PR (Brazil)

    2009-07-01

    Concerning the surrounding flora, the implementation of pipelines may cause fragmentation and isolation of the remaining natural vegetation, possibly changing the forest structure; thus raising the border effect; modifying the ratio of species and life forms, decreasing the vegetal diversity and/or causing a lack of connectivity among the remaining indigenous forest resources. In the case of pipelines, the most important environmental measure intended to mitigate the damage caused to the flora is the adoption of Indigenous Flora Rescue Programs. This paper is aimed at analyzing the programs currently applied during the implementation of the GASENE project, by conducting a case study. The main targets of such program are obtaining seeds and fruits with a view to subsidize the potential production of sapling to be further employed in the recovery of areas impacted by the pipeline works; and then relocate the most significant samples of species rescued from the suppressed areas in order to comprise forest areas adjacent to the pipeline's right-of-way. The programs had little differences in their methodology while being implemented, however, we consider that up to the present moment the results obtained in the preservation of species of native flora have been satisfactory. (author)

  3. The diel imprint of leaf metabolism on the δ13 C signal of soil respiration under control and drought conditions.

    Science.gov (United States)

    Barthel, Matthias; Hammerle, Albin; Sturm, Patrick; Baur, Thomas; Gentsch, Lydia; Knohl, Alexander

    2011-12-01

    Recent (13) CO(2) canopy pulse chase labeling studies revealed that photosynthesis influences the carbon isotopic composition of soil respired CO(2) (δ(13) C(SR)) even on a diel timescale. However, the driving mechanisms underlying these short-term responses remain unclear, in particular under drought conditions. The gas exchange of CO(2) isotopes of canopy and soil was monitored in drought/nondrought-stressed beech (Fagus sylvatica) saplings after (13) CO(2) canopy pulse labeling. A combined canopy/soil chamber system with gas-tight separated soil and canopy compartments was coupled to a laser spectrometer measuring mixing ratios and isotopic composition of CO(2) in air at high temporal resolution. The measured δ(13) C(SR) signal was then explained and substantiated by a mechanistic carbon allocation model. Leaf metabolism had a strong imprint on diel cycles in control plants, as a result of an alternating substrate supply switching between sugar and transient starch. By contrast, diel cycles in drought-stressed plants were determined by the relative contributions of autotrophic and heterotrophic respiration throughout the day. Drought reduced the speed of the link between photosynthesis and soil respiration by a factor of c. 2.5, depending on the photosynthetic rate. Drought slows the coupling between photosynthesis and soil respiration and alters the underlying mechanism causing diel variations of δ(13) C(SR). © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  4. Effect of two natural light regimes and nutrient addition on the forest herb Begonia decandra (Begoniaceae).

    Science.gov (United States)

    Cordero, R A

    2000-01-01

    The effect of two natural light-growing conditions (understory versus light gaps) and the interaction with nutrient availability (through fertilization) were studied in the understory herb Begonia decandra, in the Luquillo Experimental Forest in Puerto Rico. Sixteen potted plants obtained from cuttings were randomly chosen and distributed in each of eighth forest environments (four light gaps and four understories), for a total of 128 plants. Fertilizer was applied to half of the plants in each site. After seven months in the two given microenvironments, increased light and fertilization resulted in greater growth and some changes in the biomass allocation patterns. All measured variables responded similarly to reported changes for tree seedlings and saplings from other tropical and subtropical regions. Total growth parameters (height, biomass and leaf area) were very sensitive to increases in the main resource (light). The addition of nutrients was less important in producing changes in the allocation variables (root to shoot ratio, leaf area ratio, and specific leaf mass) under conditions of high light availability. Changes due to nutrient levels were relatively greater on plants grown under under-story conditions. Also, small light differences among sites can cause significant changes in the variables related to total growth. Lastly, plant mortality in the nutrient treatments was found to be independent of mortality in two forest light environments. Some hypotheses about resource acquisition and plant growth are not supported by this data.

  5. Stronger diversity effects with increased environmental stress: A study of multitrophic interactions between oak, powdery mildew and ladybirds.

    Science.gov (United States)

    Dillen, Mathias; Smit, Christian; Buyse, Martijn; Höfte, Monica; De Clercq, Patrick; Verheyen, Kris

    2017-01-01

    Recent research has suggested that increasing neighbourhood tree species diversity may mitigate the impact of pests or pathogens by supporting the activities of their natural enemies and/or reducing the density of available hosts. In this study, we attempted to assess these mechanisms in a multitrophic study system of young oak (Quercus), oak powdery mildew (PM, caused by Erysiphe spp.) and a mycophagous ladybird (Psyllobora vigintiduopunctata). We assessed ladybird mycophagy on oak PM in function of different neighbourhood tree species compositions. We also evaluated whether these species interactions were modulated by environmental conditions as suggested by the Stress Gradient Hypothesis. We adopted a complementary approach of a field experiment where we monitored oak saplings subjected to a reduced rainfall gradient in a young planted forest consisting of different tree species mixtures, as well as a lab experiment where we independently evaluated the effect of different watering treatments on PM infections and ladybird mycophagy. In the field experiment, we found effects of neighbourhood tree species richness on ladybird mycophagy becoming more positive as the target trees received less water. This effect was only found as weather conditions grew drier. In the lab experiment, we found a preference of ladybirds to graze on infected leaves from trees that received less water. We discuss potential mechanisms that might explain this preference, such as emissions of volatile leaf chemicals. Our results are in line with the expectations of the Natural Enemies Hypothesis and support the hypothesis that biodiversity effects become stronger with increased environmental stress.

  6. Genetic structure of a naturally regenerating post-fire seedling population: Pinus halepensis as a case study

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    Anna eGershberg

    2016-04-01

    Full Text Available To study the effects of wildfire on population genetics of a wind pollinated and wind dispersed tree, we have analyzed the genetic structure of a post-fire, naturally regenerating seedling population of Pinus halepensis Miller, on Mt. Carmel, Israel. We tested the existence of spatial genetic structure, which is expected due to the special spatial demographic structure of the post-fire seedling and sapling populations of this species. Explicitly, we asked whether or not seedlings that germinated under large, burned, dead pine trees are also their offspring. The results revealed that the post-fire seedling population is polymorphic, diverse, and reflects the pre-fire random mating system. In contrast to our prediction, we found no division of the post-fire seedling population to distinct sub-populations. Furthermore, as a result of post-fire seed dispersal to longer range than the average pre-fire inter-tree distance, seedlings found under individual burned trees were not necessarily their sole offspring. Surprisingly, although the population as a whole showed a Hardy-Weinberg equilibrium, significant excess of heterozygotes was found within each tallest seedlings group growing under single, large, burned pine trees. Our finding indicates the possible existence of intense natural selection for the most vigorous heterozygous genotypes that are best adapted to the special post-fire regeneration niche, which is the thick ash bed under large, dead, pine trees.

  7. A vegetation-focused soil-plant-atmospheric continuum model to study hydrodynamic soil-plant water relations

    Science.gov (United States)

    Deng, Zijuan; Guan, Huade; Hutson, John; Forster, Michael A.; Wang, Yunquan; Simmons, Craig T.

    2017-06-01

    A novel simple soil-plant-atmospheric continuum model that emphasizes the vegetation's role in controlling water transfer (v-SPAC) has been developed in this study. The v-SPAC model aims to incorporate both plant and soil hydrological measurements into plant water transfer modeling. The model is different from previous SPAC models in which v-SPAC uses (1) a dynamic plant resistance system in the form of a vulnerability curve that can be easily obtained from sap flow and stem xylem water potential time series and (2) a plant capacitance parameter to buffer the effects of transpiration on root water uptake. The unique representation of root resistance and capacitance allows the model to embrace SPAC hydraulic pathway from bulk soil, to soil-root interface, to root xylem, and finally to stem xylem where the xylem water potential is measured. The v-SPAC model was tested on a native tree species in Australia, Eucalyptus crenulata saplings, with controlled drought treatment. To further validate the robustness of the v-SPAC model, it was compared against a soil-focused SPAC model, LEACHM. The v-SPAC model simulation results closely matched the observed sap flow and stem water potential time series, as well as the soil moisture variation of the experiment. The v-SPAC model was found to be more accurate in predicting measured data than the LEACHM model, underscoring the importance of incorporating root resistance into SPAC models and the benefit of integrating plant measurements to constrain SPAC modeling.

  8. Forest Structure and Spesies Compotition in Taman Raya Bukit Soeharto, East Kalimantan

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    H R Syaukani

    2012-11-01

    Full Text Available 800x600 The species composition and forest structure of Taman Hutan Raya Bukit Soeharto - East Kalimantan were investigated using transect method through systematic sampling with random start design. During data collection,5 transects of 20 m width and  1 km length of each in Wanariset Semboja forest complex and 10 transects in Pusrehut UNMUL and Protection Forest areas were established. The study shows that species richness of trees in those three forest complexes are relatively similar, however, the regeneration stage in Pusrehut UNMUL forest complex is relatively higher than those in another two areas.  Medang (Litsea firma,  Acacia (Acacia sp., and Mahang (Macaranga gigantea are dominant tree species in Wanariset Semboja, Pusrehut UNMUL and Protection Forest areas, respectively.  Mahang (M. gigantea as pioneer species is also commonly dominated forest regeneration in Taman Hutan Raya Bukit Soeharto.   Based on tree’s  diameter distribution, those forests show balanced uneven-aged forests in which the large amount of trees are concentrated in the height class of 10 to 29 m.  Species diversity of those forests are relatively high (H > 2.5 either for seedling, sapling, pole or tree growth stages, however, those forests show different plant communities (IS Keywords: species composition, forest structure, species diversity, forest communities, balanced uneven-aged forest, Taman Hutan Raya Bukit Soeharto Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4

  9. Acute and long-term effects of irradiation on pine (Pinus silvestris) strands post-Chernobyl.

    Science.gov (United States)

    Arkhipov, N P; Kuchma, N D; Askbrant, S; Pasternak, P S; Musica, V V

    1994-12-11

    The effect of ionizing irradiation on the viability of pine stands after the fallout from the damaged nuclear energy plant at Chernobyl (ChNPP) was shown within the territory of the 10-km zone. During the period 1986-1991, irradiated and damaged forest stands, so-called 'red forest', located in this area were systematically classified by observation. Mortality rate, re-establishment, development of tree canopies, reproduction anomalies and stand viability were shown to be dependent on absorbed irradiation dose, on the age of the stand and on forest composition. For pine stands in the acutely affected zone, doses of more than 60 Gy resulted in a massive mortality and no regeneration of pine trees since 1987. The injured trees had burned or had dried-up. The drying process was accelerated by a massive production of pathogenic insects invading the dying trees. Specifically, irradiation doses of 10-60 Gy, 1-10 Gy and 0.1-1 Gy caused high, medium and low injury to the forest stands, respectively. Doses of less than 0.1 Gy did not cause any visible damage to the trees. In 1987, repair processes were displayed by the tree canopies and practically the entire viability of the forest stands had recovered except for trees in the acute and highly affected zones. The young forest was reestablished in the same place as the perished trees and new pine saplings were planted on the reclaimed areas.

  10. Growth of eucalyptus rooted cuttings in toxic organic waste compost of textile industry

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    Priscila F. de Souza

    2015-09-01

    Full Text Available ABSTRACTBiodegradation techniques may help contaminated organic wastes to become useful for plant production. The current study aimed to evaluate the efficiency of composting in the biodegradation of toxic residues from the textile industry and its use as substrate in saplings production. Cotton cloths contaminated with oil and grease, used in loom maintenance, were composted in a mixture with cattle manure. The composted material replaced coconut fiber in the substrate for the production of eucalyptus rooted cuttings: mixture of vermiculite, carbonized rice husk and coconut fiber in the ratio of 2:1:1 (v/v and using it as control. Thus, the amount of rice husks remained unchanged and the amount of vermiculite and compost varied. The compost proportion in the tested substrates were 0, 19, 37, 56 and 75%. The compost produced from textile wastes showed high nutrient levels and low levels of heavy metals. In general, the survival, growth and some growth indices of rooted cuttings produced on substrates with 19 and 37% compost were similar to those of rooted cuttings grown in commercial substrate. Composting is efficient and the material is useful for rooted cuttings production.

  11. The influence of gap size on plant species diversity and composition in beech (Fagus orientalis forests, Ramsar, Mazandaran Province, North of Iran

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    MARZIEH BEGYOM-FAGHIR

    2013-10-01

    Full Text Available Pourbabaei H, Haddadi-Moghaddam H, Begyom-Faghir M, Abedi T. 2013. The influence of gap size on plant species diversity and composition in beech (Fagus orientalis forests, Ramsar, Mazandaran Province, North of Iran. Biodiversitas 14: 89-94.This study was conducted to investigate the influence of gap size on plant species diversity and composition in beech (Fagus orientalis Lipsky. forests, Ramsar, Mazandaran province. Fifteen gaps in small, medium, and large sizes were randomly selected. Abundance of tree saplings, shrubs and herbaceous species were counted on 4 m2 micro-plots within the gaps. Diversity indices including Shannon-Wiener, Simpson, Mc Arthur's N1, Hill's N2, species richness and Smith-Wilson’s evenness index were computed. The results revealed that there was significant difference among three gap categories in terms of diversity. The highest diversity values of tree and herbaceous species were obtained in the large gaps, while the highest diversity value of shrub species was in the medium gaps. Species composition of small gaps (28 species: 7 trees and 21 herbaceous, medium gaps (37 species: 7 trees, 5 shrubs and 25 herbaceous and large gaps (40 species: 7 trees, 4 shrubs and 29 herbaceous were recognized. Therefore, based on the results of this study, it is recommended that in order to maintain plant diversity and composition up to 400 m2 gap size cloud be used in this forests.

  12. Re-vegetation of block-cut and milled peatlands: an Estonian example

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    T. Triisberg

    2011-06-01

    Full Text Available The re-vegetation of mined peatlands after abandonment is often a long-lasting process. The aim of this study was to clarify the factors influencing the re-vegetation of abandoned block-cut, milled and fertilised peat areas in Estonia by investigating and comparing their present vegetation. The analysis is based on 285 quadrat samples where plant species composition and cover were assessed, and the pH and electrical conductivity of bog water were measured. Whereas re-vegetation in the block-cut area was quite fast and progressive, in milled peat areas it was slow and irregular because of the absence of viable propagules and the unfavourable conditions for plant growth. The course of re-vegetation depends considerably upon the peat extraction method, the area and surface microtopography of the mined area, the pH and electrical conductivity of the bog water, and the density at which trees have established on the cutover surface. Plant species richness was most affected by the density of tree saplings, litter cover, former treatment and microtopography. A single application of fertiliser ca 25 years ago did not have a long-term effect on the total number of plant species, but did increase plant cover and the mean number of species per quadrat. On milled peatlands, neither the sowing of Oxycoccus palustris seeds nor the planting of Rubus chamaemorus had the desired effect unless growth conditions for the plants were improved.

  13. KARTAWINATA et cd: Grass communities on Oahu

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    Kuswata Kartawinata

    1972-06-01

    Full Text Available The average diameter of twenty measured old Metrosideros collinatrees in the surrounding forest was 19 ± 5 centimeters. The time requiredto reach 19 cm diameter for saplings, now having an average diameterof 1.52 cm, can be estimated by extrapolating the average diameter ofthe mature trees into the regression equation Y = 0.29 X + 12.46, givingthe value of time 610.7 ± 224.4 months (51 ± 19 years at 5% probabilitylevel. This time calculation assumes that the rate of growth is constantat 0.3 mm per month. However, in reality the rate of diameter growthmay not be constant, because diameter growth is strongly influenced bydensity. The estimated value obtained may not be accurate, but it mayserve as a rough approximation. The relationship between the diametergrowth and time is probably curvilinear, but with the short observationtime, an estimation with curvilinear regression may be misleading. It isreasonable, therefore, to predict that site I will be forested in 30 to 70years, provided the tree density remains high.

  14. Effects of drought on leaf carbon source and growth of European beech are modulated by soil type

    Science.gov (United States)

    Liu, Jian-Feng; Arend, Matthias; Yang, Wen-Juan; Schaub, Marcus; Ni, Yan-Yan; Gessler, Arthur; Jiang, Ze-Ping; Rigling, Andreas; Li, Mai-He

    2017-02-01

    Drought potentially affects carbon balance and growth of trees, but little is known to what extent soil plays a role in the trade-off between carbon gain and growth investment. In the present study, we analyzed leaf non-structural carbohydrates (NSC) as an indicator of the balance of photosynthetic carbon gain and carbon use, as well as growth of European beech (Fagus sylvatica L.) saplings, which were grown on two different soil types (calcareous and acidic) in model ecosystems and subjected to a severe summer drought. Our results showed that drought led in general to increased total NSC concentrations and to decreased growth rate, and drought reduced shoot and stem growth of plants in acidic soil rather than in calcareous soil. This result indicated that soil type modulated the carbon trade-off between net leaf carbon gain and carbon investment to growth. In drought-stressed trees, leaf starch concentration and growth correlated negatively whereas soluble sugar:starch ratio and growth correlated positively, which may contribute to a better understanding of growth regulation under drought conditions. Our results emphasize the role of soil in determining the trade-off between the balance of carbon gain and carbon use on the leaf level and growth under stress (e.g. drought).

  15. Management of Chinese Rose Beetle (Adoretus sinicus) Adults Feeding on Cacao (Theobroma cacao) Using Insecticides.

    Science.gov (United States)

    Spafford, Helen; Ching, Alexander; Manley, Megan; Hardin, Chelsea; Bittenbender, Harry

    2016-06-24

    The Chinese rose beetle (Adoretus sinicus Burmeister (Coleoptera: Scarabaeidae)) is an introduced, widely-established pest in Hawai'i. The adult beetles feed on the leaves of cacao (Theobroma cacao L.), which can lead to defoliation and even death of young trees. We evaluated the impact of five commercially available products with different active ingredients (imidacloprid, azadirachtin, Beauveria bassiana (Bals.-Criv.) Vuill., kaolin clay, and pyrethrin) and the presence or absence of weed mat cover in reducing adult beetle feeding on sapling cacao in the field. The use of weed mat cover reduced feeding damage compared to the untreated control, as did foliar application of imidacloprid, azadirachtin, and B. bassiana. In the laboratory, field-collected adult beetles were presented cacao leaf samples dipped in one of the five products and compared to a control. Beetles exposed to pyrethrin died rapidly. Among the other treatments, only exposure to imidacloprid significantly reduced survival relative to the control. Beetles fed very little on leaf samples with azadirachtin but their longevity was not significantly reduced. Imidacloprid, azadirachtin, and weed mat application had the most promise for reducing adult Chinese rose beetle feeding damage in young cacao and deserve further investigation for successful management of this significant pest.

  16. Domination and Composition Structure Change at Hemic Peat Natural Regeneration Following Burning; A Case Study in Pelalawan, Riau Province

    Directory of Open Access Journals (Sweden)

    BAMBANG HERO SAHARJO

    2006-04-01

    Full Text Available Biomass burning is the burning of the world’s living and dead vegetation, including grasslands, forests and agricultural lands following the harvest for land clearing and land-use change. One of the important information needed following this biomass burning is how long the burnt forest or land can be recovered, and how worst the changing occurred. Repeated burning occurred at the same place trend to clean the vegetation which leads to have the land with lower number and quality of species left. The research objective is to understand the vegetation changing following peat fires in the sapric peat type at the land preparation using belong to the local community located in the Pelalawan district, Riau province, Indonesia during the dry season in the year 2001. Before burning, logging, slashing, drying and burning the site was dominated by Uncaria glabrata at seedling stage, Ficus sundaica at sapling stage, Ficus sundaica at pole stage and Stenochlaena palustris at understorey. After logging, slashing and followed by 4 weeks drying then continued by burning with high flame temperature range from 900-1100oC, it had been found that 3-months following burning the site was dominated by Uncaria glabrata at seedling stage and Nephrolepis flaccigera at understorey while 6-months following burning the site was dominated by Parastemon uruphyllus at seedling stage and Erechites valeriantifolia at understorey stage.

  17. Field Bending Tests of Three Riparian Species Common to the Central Platte River: Resistance, Rigidity and Plant Streamlining

    Science.gov (United States)

    Thomas, R. E.; Bankhead, N. L.; Simon, A.

    2010-12-01

    old saplings, mean J was 0.008 ± 0.008 N m2 (n = 23), whilst for 2-3 year old branches, mean J was 1.64 ± 1.86 N m2 (n = 80). J-values of reed canary grass and phragmites australis were 0.18 ± 0.17 N m2 (n = 62) and 1.26 ± 1.1 N m2 (n = 59), respectively. It was observed that the measured strengths of reed canary grass and phragmites australis stems were sensitive to whether load was applied in an upstream or downstream direction. Preliminary analyses suggest that during our bending tests, the projected area of cottonwood saplings reduced by 14%, whilst that of the 2-3 year old branches reduced by 36%. The projected area of neither reed canary grass nor phragmites australis changed significantly during bending. These results have important implications for both laboratory and numerical modeling efforts aimed at quantifying the interactions between in-channel flows and vegetation.

  18. Potencial invasor de Syzigium jambos (Myrtaceae en fragmentos boscosos: el caso de Ciudad Colón, Costa Rica

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    José Fco. Di Stéfano

    1998-09-01

    Full Text Available Syzigium jambos es una especie de uso múltiple originaria del Sur-Este de Asia, la cual ha sido introducida en muchos países del mundo. Así como algunas otras exóticas, tiene el potencial de naturalizarse y de invadir ecosistemas naturales. En Costa Rica, se ha observado en varios fragmentos boscosos. Se establecieron 48 parcelas de 0.6 m en una hectárea de bosque secuendario de 30 años. Pertenece a la zona de vida del Premontano húmedo. Se estimó que la especie exótica alcanzó una densidad de 4.9 plántulas y 0.16 juveniles por m². La mayor densidad se observó cerca de la base del árbol adulto y el árbol más grueso. El crecimiento de las plantas fue muy bajo con tasas anuales menores a 10.5 y 0.25 cm en altura y diámetro basal, respectivamente. En general, se observaron daños relativos menores al 30% aunque se registró un aumento importante al finalizar la época lluviosa y el inicio de la seca. Las hojas maduras presentaron una abundante cantidad de manchas blaquecinas pequeñas producto de un líquen costroso epífilo. Aparentemente la planta es muy flexible puesto que los daños mecánicos fueron muy bajos.Syzigium jambos is a multiple use species native to Southeast Asia that has been introduced in many countries of the world. Similar to some other exotics, it has the potential to become naturalized and invade natural ecosystems. In Costa Rica, it has been observed in several small preserves. A sample of 48 quadrats of 0.6 m of radius, in one hectare fragment (with a 30 year-old secundary humid Premontane forest had a density of 4.9 seedlings and 0.16 saplings per m2. Higher densities were observed near the base of the adult trees (N=3 and on the biggest of the trees investigated. Growth rates of the seedlings and saplings was very low: less than 10.5 and 0.25 cm/year in height and basal diameter, respectively. In general, the plants had low levels (<30% of relative damage by herbivores, and fungi (one identified as a

  19. Interaction of CO2 concentrations and water stress in semiarid plants causes diverging response in instantaneous water use efficiency and carbon isotope composition

    Science.gov (United States)

    Zhao, Na; Meng, Ping; He, Yabing; Yu, Xinxiao

    2017-07-01

    In the context of global warming attributable to the increasing levels of CO2, severe drought may be more frequent in areas that already experience chronic water shortages (semiarid areas). This necessitates research on the interactions between increased levels of CO2 and drought and their effect on plant photosynthesis. It is commonly reported that 13C fractionation occurs as CO2 gas diffuses from the atmosphere to the substomatal cavity. Few researchers have investigated 13C fractionation at the site of carboxylation to cytoplasm before sugars are exported outward from the leaf. This process typically progresses in response to variations in environmental conditions (i.e., CO2 concentrations and water stress), including in their interaction. Therefore, saplings of two typical plant species (Platycladus orientalis and Quercus variabilis) from semiarid areas of northern China were selected and cultivated in growth chambers with orthogonal treatments (four CO2 concentration ([CO2]) × five soil volumetric water content (SWC)). The δ13C of water-soluble compounds extracted from leaves of saplings was determined for an assessment of instantaneous water use efficiency (WUEcp) after cultivation. Instantaneous water use efficiency derived from gas-exchange measurements (WUEge) was integrated to estimate differences in δ13C signal variation before leaf-level translocation of primary assimilates. The WUEge values in P. orientalis and Q. variabilis both decreased with increased soil moisture at 35-80 % of field capacity (FC) and increased with elevated [CO2] by increasing photosynthetic capacity and reducing transpiration. Instantaneous water use efficiency (iWUE) according to environmental changes differed between the two species. The WUEge in P. orientalis was significantly greater than that in Q. variabilis, while an opposite tendency was observed when comparing WUEcp between the two species. Total 13C fractionation at the site of carboxylation to cytoplasm before sugar

  20. SUKSESI VEGETASI ALAMI DI BEKAS TAMBANG TIMBAH PULAU BANGKA (Succession of Natural Vegetation in Post Tin-Mining Bangka Island

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    Guat Tjhiaw

    2009-03-01

    Full Text Available ABSTRAK  Penelitian ini mempelajari suksesi vegetasi alami berbagai umur sere di bekas tambang timah Pulau Bangka. Komunitas sere tersebut terdiri dari overburdern 2 bulan, overburden 1 tahun, subsoil 1 tahun, tailing 3 tahun, overburden 20 tahun dan tailing > 20 tahun. Hasil tersebut dibandingkan dengan hutan alam yang belum ditambang. Metode yang digunakan adalah kuadrat plot yang disesuaikan dengan persebaran vegetasi di lokasi dengan ukuran 2m x 4 m, 5m x 5m dan 10m x 20 m serta ulangan berkisar 30-15 kali. Hasil penelitian menunjukkan bahwa growthform komunitas sere overburden lebih banyak dibandingan dengan tailing. Vegetasi yang dominan pada sere awal adalah rumput Ischaemum muticum dan Imperata cylindrica. Pada sere selanjutnya didominasi oleh semak Melastoma malbathricum, juga ditemukan familia Leguminosae dan Nepenthes sp sebagai indikator miskinnya hara tanah. Sedangkan seedling pohon terbesar jarang terdiri dari Macaranga sp, Malleuca leucadendron, Schima wallichii, Viotex pubescens, Anacardium occidentale, dan Alstonia schoolaris. Ternyata kehadiran vegetasi merespon pada kandungan hara, terutama bahan organik dan nitrat. Pada komunitas sere overburden 20 tahun, serta tailing > 20 tahun ditemukan introduce species, yaitu Acacia spp. Adanya pohon Dyera costulata (jelutung di hutan alam sebagai indikasi hutan tersebut adalah hutan rawa gambut. Sebaliknya pada hutan alam dengan tekstur tanahnya mirip dengan tekstur tanah pada semua komunitas sere didominasi oleh pohon dan sapling Eugenia palembanica serta seedling Eugenia longiflora.   ABSTRACT Succession of natural vegetation at various seral-stages were studied in post tin-mining Bangka Island. These seral stages were 2 months of overburden, 1 year of tailing, 1 year of subsoil, 3 years of tailing, 10 years of overburden, 10 years of tailing, 20 years of overburden, and 20 years of tailing and were compared to the natural forest. Data were collected based on various growthforms

  1. Interaction of CO2 concentrations and water stress in semiarid plants causes diverging response in instantaneous water use efficiency and carbon isotope composition

    Directory of Open Access Journals (Sweden)

    N. Zhao

    2017-07-01

    Full Text Available In the context of global warming attributable to the increasing levels of CO2, severe drought may be more frequent in areas that already experience chronic water shortages (semiarid areas. This necessitates research on the interactions between increased levels of CO2 and drought and their effect on plant photosynthesis. It is commonly reported that 13C fractionation occurs as CO2 gas diffuses from the atmosphere to the substomatal cavity. Few researchers have investigated 13C fractionation at the site of carboxylation to cytoplasm before sugars are exported outward from the leaf. This process typically progresses in response to variations in environmental conditions (i.e., CO2 concentrations and water stress, including in their interaction. Therefore, saplings of two typical plant species (Platycladus orientalis and Quercus variabilis from semiarid areas of northern China were selected and cultivated in growth chambers with orthogonal treatments (four CO2 concentration ([CO2]  ×  five soil volumetric water content (SWC. The δ13C of water-soluble compounds extracted from leaves of saplings was determined for an assessment of instantaneous water use efficiency (WUEcp after cultivation. Instantaneous water use efficiency derived from gas-exchange measurements (WUEge was integrated to estimate differences in δ13C signal variation before leaf-level translocation of primary assimilates. The WUEge values in P. orientalis and Q.  variabilis both decreased with increased soil moisture at 35–80 % of field capacity (FC and increased with elevated [CO2] by increasing photosynthetic capacity and reducing transpiration. Instantaneous water use efficiency (iWUE according to environmental changes differed between the two species. The WUEge in P. orientalis was significantly greater than that in Q. variabilis, while an opposite tendency was observed when comparing WUEcp between the two species. Total 13C fractionation at the site of

  2. Dieback of Acacia koa in Hawaii: Ecological and pathological characteristics of affected stands

    Science.gov (United States)

    Anderson, R.C.; Gardner, D.E.; Daehler, C.C.; Meinzer, F.C.

    2002-01-01

    Koa (Acacia koa) is an endemic Hawaiian tree that serves as a keystone species in the upper elevation forests of all the main islands. In the Mauna Loa Strip area of Hawaii Volcanoes National Park, mature koa stands are suffering from an unexplained dieback that has increased in severity since it was first noticed approximately 25 years ago. The dieback is often evident in patches, and generally spreads within stands in a radial fashion from a localized infection center. Entire crowns of affected trees become wilted, with foliage gradually progressing from an apparent healthy to a completely chlorotic condition. Although most trees die soon after the onset of symptoms, some trees are able to survive crown death by producing epicormic shoots on the lower portions of the trunk. Previously published studies reported that a vascular wilt fungus (Fusarium oxysporum f. sp. koae) was associated with koa seeds and the rhizosphere of healthy and dieback-affected koa stands. The purpose of this study was to characterize the stand structure, soil conditions, and physiological condition of dieback-affected trees, and to assess the possible role of F. oxysporum f. sp. koae in the current dieback stands. This fungus was isolated from branches of symptomatic koa in dieback-affected stands and roots from healthy and dieback-affected stands. Possible differences in the pathogenicity and virulence of F. oxysporum f. sp. koae isolates obtained from the roots of healthy koa in unaffected stands and those from branches of dieback-affected koa were determined by greenhouse inoculations of koa seedlings. Healthy koa saplings in stands unaffected by dieback were also inoculated to determine if disease symptoms could be induced by inoculation of injured roots in the field. Both branch and root isolates were pathogenic; with the percent mortality of inoculated seedlings ranging from 30 to 60% for all isolates. Disease severity between branch and root isolates was not significantly different

  3. Seletividade dos herbicidas setoxidim, isoxaflutol e bentazon a espécies arbóreas nativas Selectivity of the herbicides sethoxydim, isoxaflutole and bentazon on native tree species

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Santin Brancalion

    2009-03-01

    dry mass were evaluated. In another experiments, the recommended doses of the same herbicides were applied to other 22 native tree species, for which the leaf dry mass was evaluated. The experiments were carried out in completely randomized design with four replicates. Each experimental plot comprised one sapling in initial developmental stage. The herbicides did not cause saplings death, even though all of them showed phytotoxicity symptoms. Herbicide application reduced the leaf dry mass as follows: isoxaflutole, 20% of the species; bentazon, one of the species; and sethoxydim did not reduce leaf dry mass in any of the species.

  4. Rangelands management in Spanish Natura 2000 sites.

    Science.gov (United States)

    Hernando Gallego, A.; Tejera Gimeno, R.; Velázquez Saornil, J.; Núñez Martí, V.; Grande Vega, M.

    2009-04-01

    Spanish open oak woodlands have had multiple land uses such as firewood extraction and grazing through centuries. Consequently, 20% of the Spanish forest is coppice forest. This particular agrosilvopastoral system is well widespread in the southern and western part of the Iberian Peninsula. As a result of the implementation of Natura 2000 in Spain, many of these habitats have been included in this network listed as "Dehesas" with evergreen Quercus spp. (Sclerophyllous grazed forests -dehesas-). The main goal of Natura 2000 is assuring "favourable conservation status" of natural habitats and species within these areas (Habitats Directive 92/43/ECC). This is the case of the study area, "Dehesa Boyal" (Ávila), which management plan has been carried out in a public forest land. The current situation is a degraded coppice forest, Quercus pyrenaica and Q.ilex, with a shrub encroachment due to previous firewood extraction. Besides, problems such as soil compaction and lack of sexual have been observed presumably related with livestock (180 horses, 1100 goats, 900 sheeps and 190 cows distributed in different seasons). Livestock feed on the acorns and hedge young sprouts making them sprouting again. The shrub encroachment is far from "conservation status" required in Natura 2000. Furthermore, the livestock cannot be removed because it is an important part of this agrosilvopastoral system not only for the landscape but also for its economic importance to local owners. Management plans should consider all of these circumstances and propose an integrated approach. To achieve this goal, the area was accurately classified in age classes by "stands" (oak shrubland, low pole stages, coppice tall shrub and sapling) in each habitat, using Geographic Information Systems (G.I.S), remote sensing techniques and detailed field work. Then, the "conservation status" of each stand is classified in A (Favourable), B (Inconvenient) and C (Unfavourable conservation status) considering some

  5. Struktur komunitas mangrove dan strategi pengelolaannya di Kabupaten Pidie, Province Aceh (Community structure of mangrove and its management strategy in Pidie District, Aceh Province

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    Mirza Karnanda

    2016-12-01

    Full Text Available The objective of the present study was to analyze the community structure of mangrove vegetation in Pidie District, Aceh Province and to plan its management strategies. The study was conducted from August to November 2014 in three subdistricts namely Batee, Kota Sigli, and Simpang Tiga. A total of three sampling stations were determined purposively at every subdistrict where every station has two substations and every substation has three sampling plots of 10 m x 10 m. In addition, a total of 297 respondents as representative of the fish farmer, fishermen, and other stakeholders were interviewed to collect data to plan the management strategies using the SWOT (Strengths, Weaknesses, Opportunities, Threats analysis. The results showed that there were six species of mangrove found in Pidie District namely Avicennia alba, A. officinalis, A. marina, Rhizophora mucronata, R. apiculata and Sonneratia alba. For seedlings and saplings categories can be classified into very good condition, except in Kecamatan Batee  where S. alba for seedlings was classified into moderate damage and the saplings was in highly damaged condition. The mangrove of trees category was classified into heavily damaged condition. The management strategies of mangrove ecosystem in Kabupaten Pidie can be done by maximizing the function of mangrove ecosystems by replanting the species of mangrove that match with the habitat for their life so that can produce the specific functions; improve the role of government and society in controlling and monitoring the mangrove ecosystems; and establish the local regulations about the management of mangrove ecosystems in Kabupaten Pidie. Penelitian ini bertujuan untuk menganalisis struktur komunitas vegetasi mangrove dan menetapkan strategi pengelolaannya di Kabupaten Pidie Provinsi Aceh. Penelitian ini dilaksanakan pada Agustus sampai November 2014 pada tiga kecamatan yaitu Kecamatan Batee, Kota Sigli, dan Kecamatan Simpang Tiga. Metode yang

  6. Pengaruh Aktivitas Masyarakat terhadap Kerusakan Hutan Mangrove di Rarowatu Utara, Bombana Sulawesi Tenggara

    Directory of Open Access Journals (Sweden)

    Wa Alimuna

    2016-10-01

    oleh tindakan pencegahan kerusakan hutan mangrove, pada tingkat sedang (41,67%.   ABSTRACT Presence of mangrove forest is very necessary because it serve ecological and economical functions to beach inhabitants’ life. Mangrove forest was damaged as result of inhabitants’ behavior to open embankment area, fishing, and illegal logging due to big demand for wood products. Objectives of research were (1 to study damage rate of mangrove forest; (2 to study inhabitants’ activity affecting damage of mangrove forest; (3 to study factors having effects of inhabitants’ activity on damage of mangrove forest; (4 to study roles of inhabitants in cultivating the mangrove forest. Methods used in this research were survey methods through interview using questionnaires. Data were analyzed by using cross-tables, the results were analyzed descriptively. Results of research indicated that, from calculation of INP (Important Value Index, it was known that types of mangrove vegetation dominating and having important role in mangrove forest in Watumentade Village were types of Bruguiera gymnorrhiza (rate of seedling (92.21, rate of sapling (87.98, and rate of trees (139.84; and in Tunas Baru Village were types of Rhizophora mucronata (rate of seedling (67.52; rate of sapling, (73.52; and rate of trees (80.88. Inhabitants’ activity affecting damage of mangrove forest included activity of embankment, and illegal logging used as firewood and building materials. Factors of social-economic condition affecting inhabitants’ activity included formal education, knowledge, and inhabitants’ income. Factors of educational level, knowledge (function and benefit of mangrove forest and income affected inhabitants’ activity in uses of embankment area were causing damage of mangrove forest. Inhabitants’ role in cultivating mangrove forest was aimed by mangrove forest damage prevention at medium rate (41.67%.

  7. Comparação fitossociológica entre duas amostragens numa área de clareira em anos consecutivos, Estação Biológica de Caratinga, MG Phytosociology comparing between two gaps in the Caratinga Biologic Station, Minas Gerais State

    Directory of Open Access Journals (Sweden)

    Leonardo Vianna da Costa e Silva

    1993-12-01

    Full Text Available A Estação Biológica de Caratinga encontra-se dentro do domínio Atlântico, sob um clima sazonal com uma estação úmida e quente (outubro-março e outra seca e fria (abril-setembro. O solo é do tipo Latossolo Vermelho-Amarelo álico. A clareira em estudo localiza-se em topo de morro, possuindo pequenas árvores esparsas, grande quantidade de "touceiras" mortas de Pteridium aquilinum, plantas herbáceas, jovens e plântulas de espécies arbóreas. Esta área foi alterada por fogo e plantio de café há pouco mais de 30 anos. Foram amostrados 500 m² mapeando-se e anotando-se altura e circunferência de todos os indivíduos. Realizaram-se 2 amostragens com o mesmo método, a primeira em outubro de 1989 e a segunda em outubro de 1990. Verificou-se pouca variação na densidade (657 e 668 indivíduos, respectivamente e na composição em espécies. Mabea fistulifera (maior densidade em ambas as amostragens, Bauhinia fusco-nervis, Inga sp e uma espécie não identificada de gramínea tiveram a densidade aumentada, enquanto Pteridium aquilinum (a segunda de maior densidade, Ferdinandusa cf. ruggeoides e Vismia sp, tiveram-na reduzida. A presença de "touceiras" mortas de P. aquilinum, de indivíduos jovens de espécie arbóreas comuns às matas ao redor e a existência de áreas vizinhas ocupadas exclusivamente por populações de P. aquilinum sugerem que a clareira em estudo encontra-se em estágio intermediário entre o declínio da população de P. aquilinum e a ocupação da área pelas espécies de mata.The Estação Biológica de Caratinga is located in the Atlantic dominium, The climate is seasonal with a humid hot season (October-March and a dry cold season (April-September. The soil is alic Yelowish-Red Latosol. The gap studied is located on the top of a hill, where there are small scattered trees, a large amount of dead bunches of Pteridium aquilinum, herbs, and saplings of tree species. The position of each individual was mapped, and

  8. [Ecological protection of medicinal woody plants].

    Science.gov (United States)

    Yan, Xiufeng

    2003-09-01

    Medicinal woody plants, especially medicinal tall trees, play a same important role in forest structure, ecological balance and timber production as other tree species in forest, and due to their additional medicinal values overuse of these trees is more intensive than others. Many medicinal materials are destructively obtained from plants such as roots or bark used as medicinal materials. The contradiction between the utilization and protection of medicinal woody plants becomes more and more incisive. In the present paper, based on the analysis of the utilized situation and specialty of medicinal woody plants, the trouble between the plants protection and utilization was observed, the method to solve it and the fundamental research work needs to be developed were discussed. The following aspects of researches were suggested to be conducted: (a) study on the distribution in organs, seasonal and age variations, and correlation with environmental factors of principal medicinal compositions in mature trees to clear the optimum of harvest and cultivation conditions; (b) study on the distribution in organs, seasonal and age variations, and correlation with environmental factors of principal medicinal compositions in saplings, especially the time course of the variation in medicinal compositions and biomass to achieve the optimal tree ages for the balance between biomass and production of medicinal products during saplings development; (c) study on the influence and regulation of environmental factors on medicinal compounds production in woody plants to look for the optimal cultivated conditions for optimizing the accumulation of biomass and medicinal chemicals; (d) further study on the regulatory mechanism of the induced production of main medicinal compositions by ecological factors at protein (key enzyme) and gene level to accumulate fundamental data for the enhancement of quality and quantity, and approach of new accesses to medicinal products using biological

  9. Do rock fragments participate to plant water and mineral nutrition?

    Science.gov (United States)

    Korboulewsky, Nathalie; Tétégan, Marion; Besnault, Adeline; Cousin, Isabelle

    2010-05-01

    Rock fragments modify soil properties, and can be a potential reservoir of water. Besides, recent studies showed that this coarse soil fraction is chemically active, release nutrients, and could therefore be involved in biogeochemical nutrient cycles. However, these studies carried out on rock fragments, crushed pebbles or mineral particles do not answer the question whether the coarse soil fraction has significant nutritive functions. Only a couple of studies were conducted on plants, one on grass and the other on coniferous seedlings. This present work attempted to assess if pebbles may act as water and nutrient sources for poplar saplings, a deciduous species. Remoulded soils were set up in 5 L-pots with three percentages of pebbles: 0, 20, and 40% in volume. We used, as substrate either fine earth or sand (quartz), and as rock fragments either calcareous or inert pebbles (quartz). Additional modalities were settled with sand mixed with 20 and 40% pebbles enriched with nutrients. Both fine earth and calcareous pebbles were collected from the Ap horizon of a calcareous lacustrine limestone silty soil located in the central region of France. After cleaning, all pebbles were mixed to reach a bulk density in pots of 1.1 g/cm3 for the fine earth and 1.5 g/cm3 for the sand. Ten replicates were settled per modality, and one cutting of Populus robusta was planted in each. The experiment was conducted under controlled conditions. All pots were saturated at the beginning of the experiment, then irrigated by capillarity and controlled to maintain a moderate water stress. Growth and evapotranspiration were followed regularly, while water stress status was measured by stomatal conductivity every day during two drying periods of 10 days. After three months, plants were collected, separated in below- and above-ground parts for biomass and cation analysis (Ca, Mg, K). Results showed that pebbles can participate to plant nutrition, but no reduction of water stress was observed

  10. Nitrogen metabolism of two contrasting poplar species during acclimation to limiting nitrogen availability

    Science.gov (United States)

    Luo, Zhi-Bin

    2013-01-01

    To investigate N metabolism of two contrasting Populus species in acclimation to low N availability, saplings of slow-growing species (Populus popularis, Pp) and a fast-growing species (Populus alba × Populus glandulosa, Pg) were exposed to 10, 100, or 1000 μM NH4NO3. Despite greater root biomass and fine root surface area in Pp, lower net influxes of NH4 + and NO3 – at the root surface were detected in Pp compared to those in Pg, corresponding well to lower NH4 + and NO3 – content and total N concentration in Pp roots. Meanwhile, higher stable N isotope composition (δ15N) in roots and stronger responsiveness of transcriptional regulation of 18 genes involved in N metabolism were found in roots and leaves of Pp compared to those of Pg. These results indicate that the N metabolism of Pp is more sensitive to decreasing N availability than that of Pg. In both species, low N treatments decreased net influxes of NH4 + and NO3 –, root NH4 + and foliar NO3 – content, root NR activities, total N concentration in roots and leaves, and transcript levels of most ammonium (AMTs) and nitrate (NRTs) transporter genes in leaves and genes involved in N assimilation in roots and leaves. Low N availability increased fine root surface area, foliar starch concentration, δ15N in roots and leaves, and transcript abundance of several AMTs (e.g. AMT1;2) and NRTs (e.g. NRT1;2 and NRT2;4B) in roots of both species. These data indicate that poplar species slow down processes of N acquisition and assimilation in acclimation to limiting N supply. PMID:23963674

  11. Drought-adaptation potential in Fagus sylvatica: linking moisture availability with genetic diversity and dendrochronology.

    Directory of Open Access Journals (Sweden)

    Andrea R Pluess

    trees, fostering saplings originating from dry sites and grown within mesic sites might increase resistance of beech forests during the anticipated longer dry periods.

  12. Canopy conductance of Pinus taeda, Liquidambar styraciflua and Quercus phellos under varying atmospheric and soil water conditions.

    Science.gov (United States)

    Pataki, D. E.; Oren, R.; Katul, G.; Sigmon, J.

    1998-05-01

    Sap flow, and atmospheric and soil water data were collected in closed-top chambers under conditions of high soil water potential for saplings of Liquidambar styraciflua L., Quercus phellos L. and Pinus taeda L., three co-occurring species in the southeastern USA. Responses of canopy stomatal conductance (g(t)) to water stress induced by high atmospheric water vapor demand or transpiration rate were evaluated at two temporal scales. On a diurnal scale, the ratio of canopy stomatal conductance to maximum conductance (g(t)/g(t,max)) was related to vapor pressure deficit (D), and transpiration rate per unit leaf area (E(l)). High D or E(l) caused large reductions in g(t)/g(t,max) in L. styraciflua and P. taeda. The response of g(t)/g(t,max) to E(l) was light dependent in L. styraciflua, with higher g(t)/g(t,max) on sunny days than on cloudy days. In both L. styraciflua and Q. phellos, g(t)/g(t,max) decreased linearly with increasing D (indicative of a feed-forward mechanism of stomatal control), whereas g(t)/g(t,max) of P. taeda declined linearly with increasing E(l) (indicative of a feedback mechanism of stomatal control). Longer-term responses to depletion of soil water were observed as reductions in mean midday g(t)/g(t,max), but the reductions did not differ significantly between species. Thus, species that employ contrasting methods of stomatal control may show similar responses to soil water depletion in the long term.

  13. 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.

  14. Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection.

    Science.gov (United States)

    Hughes, David P; Andersen, Sandra B; Hywel-Jones, Nigel L; Himaman, Winanda; Billen, Johan; Boomsma, Jacobus J

    2011-05-09

    Parasites that manipulate host behavior can provide prominent examples of extended phenotypes: parasite genomes controlling host behavior. Here we focus on one of the most dramatic examples of behavioral manipulation, the death grip of ants infected by Ophiocordyceps fungi. We studied the interaction between O. unilateralis s.l. and its host ant Camponotus leonardi in a Thai rainforest, where infected ants descend from their canopy nests down to understory vegetation to bite into abaxial leaf veins before dying. Host mortality is concentrated in patches (graveyards) where ants die on sapling leaves ca. 25 cm above the soil surface where conditions for parasite development are optimal. Here we address whether the sequence of ant behaviors leading to the final death grip can also be interpreted as parasite adaptations and describe some of the morphological changes inside the heads of infected workers that mediate the expression of the death grip phenotype. We found that infected ants behave as zombies and display predictable stereotypical behaviors of random rather than directional walking, and of repeated convulsions that make them fall down and thus precludes returning to the canopy. Transitions from erratic wandering to death grips on a leaf vein were abrupt and synchronized around solar noon. We show that the mandibles of ants penetrate deeply into vein tissue and that this is accompanied by extensive atrophy of the mandibular muscles. This lock-jaw means the ant will remain attached to the leaf after death. We further present histological data to show that a high density of single celled stages of the parasite within the head capsule of dying ants are likely to be responsible for this muscular atrophy. Extended phenotypes in ants induced by fungal infections are a complex example of behavioral manipulation requiring coordinated changes of host behavior and morphology. Future work should address the genetic basis of such extended phenotypes.

  15. Soil microbial communities buffer physiological responses to drought stress in three hardwood species.

    Science.gov (United States)

    Kannenberg, Steven A; Phillips, Richard P

    2017-03-01

    Trees possess myriad adaptations for coping with drought stress, but the extent to which their drought responses are influenced by interactions with soil microbes is poorly understood. To explore the role of microbes in mediating tree responses to drought stress, we exposed saplings of three species (Acer saccharum, Liriodendron tulipifera, and Quercus alba) to a four week experimental drought in mesocosms. Half of the pots were inoculated with a live soil slurry (i.e., a microbial inoculum derived from soils beneath the canopies of mature A. saccharum, L. tulipifera or Q. alba stands), while the other half of the pots received a sterile soil slurry. Soil microbes ameliorated drought stress in L. tulipifera by minimizing reductions in leaf water potential and by reducing photosynthetic declines. In A. saccharum, soil microbes reduced drought stress by lessening declines in leaf water potential, though these changes did not buffer the trees from declining photosynthetic rates. In Q. alba, soil microbes had no effects on leaf physiological parameters during drought stress. In all species, microbes had no significant effects on dynamic C allocation during drought stress, suggesting that microbial effects on plant physiology were unrelated to source-sink dynamics. Collectively, our results suggest that soil microbes have the potential to alter key parameters that are used to diagnose drought sensitivity (i.e., isohydry or anisohydry). To the extent that our results reflect dynamics occurring in forests, a revised perspective on plant hydraulic strategies that considers root-microbe interactions may lead to improved predictions of forest vulnerability to drought.

  16. Isohydric species are not necessarily more carbon limited than anisohydric species during drought.

    Science.gov (United States)

    Garcia-Forner, N; Biel, C; Savé, R; Martínez-Vilalta, J

    2017-04-01

    Isohydry (i.e., strong regulation of leaf water potential, Ψl) is commonly associated with strict stomatal regulation of transpiration under drought, which in turn is believed to minimize hydraulic risk at the expense of reduced carbon assimilation. Hence, the iso/anisohydric classification has been widely used to assess drought resistance and mortality mechanisms across species, with isohydric species being hypothetically more prone to carbon starvation and anisohydric species more vulnerable to hydraulic failure. These hypotheses and their underlying assumptions, however, have rarely been tested under controlled, experimental conditions. Our objective is to assess the physiological mechanisms underlying drought resistance differences between two co-occurring Mediterranean forest species with contrasting drought responses: Phillyrea latifolia L. (anisohydric and more resistant to drought) and Quercus ilex L. (isohydric and less drought resistant). A total of 100 large saplings (50 per species) were subjected to repeated drought treatments for a period of 3 years, after which Q. ilex showed 18% mortality whereas no mortality was detected in P. latifolia. Relatively isohydric behavior was confirmed for Q. ilex, but higher vulnerability to cavitation in this species implied that estimated embolism levels were similar across species (12-52% in Q. ilex vs ~30% in P. latifolia). We also found similar seasonal patterns of stomatal conductance and assimilation between species. If anything, the anisohydric P. latifolia tended to show lower assimilation rates than Q. ilex under extreme drought. Similar growth rates and carbon reserves dynamics in both species also suggests that P. latifolia was as carbon-constrained as Q. ilex. Increasing carbon reserves under extreme drought stress in both species, concurrent with Q. ilex mortality, suggests that mortality in our study was not triggered by carbon starvation. Our results warn against making direct connections between

  17. The impact of winter and spring temperatures on temperate tree budburst dates: results from an experimental climate manipulation.

    Directory of Open Access Journals (Sweden)

    Yongshuo H Fu

    Full Text Available Budburst phenology is a key driver of ecosystem structure and functioning, and it is sensitive to global change. Both cold winter temperatures (chilling and spring warming (forcing are important for budburst. Future climate warming is expected to have a contrasting effect on chilling and forcing, and subsequently to have a non-linear effect on budburst timing. To clarify the different effects of warming during chilling and forcing phases of budburst phenology in deciduous trees, (i we conducted a temperature manipulation experiment, with separate winter and spring warming treatments on well irrigated and fertilized saplings of beech, birch and oak, and (ii we analyzed the observations with five temperature-based budburst models (Thermal Time model, Parallel model, Sequential model, Alternating model, and Unified model. The results show that both winter warming and spring warming significantly advanced budburst date, with the combination of winter plus spring warming accelerating budburst most. As expected, all three species were more sensitive to spring warming than to winter warming. Although the different chilling requirement, the warming sensitivity was not significantly different among the studied species. Model evaluation showed that both one- and two- phase models (without and with chilling, respectively are able to accurately predict budburst. For beech, the Sequential model reproduced budburst dates best. For oak and birch, both Sequential model and the Thermal Time model yielded good fit with the data but the latter was slightly better in case of high parameter uncertainty. However, for late-flushing species, the Sequential model is likely be the most appropriate to predict budburst data in a future warmer climate.

  18. The ecological consequences of forest elephant declines for Afrotropical forests.

    Science.gov (United States)

    Poulsen, John R; Rosin, Cooper; Meier, Amelia; Mills, Emily; Nunez, Chase; Koerner, Sally E; Blanchard, Emily; Callejas, Jennifer; Moore, Sarah; Sowers, Mark

    2017-10-27

    Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas of elephant-free tropical forest. Elephants are ecological engineers that create and maintain forest habitat, thus their loss will have strong consequences for the composition and structure of Afrotropical forests. We evaluated the roles of forest elephants in seed dispersal, nutrient recycling, and herbivory and physical damage to predict the cascading ecological effects of their population declines. Loss of seed dispersal by elephants will favor tree species dispersed abiotically and by smaller dispersal agents, with tree species composition depending on the downstream effects of changes in elephant nutrient cycling and browsing. Loss of trampling and herbivory of seedlings and saplings will result in high tree density as they are released from the pressures of browsing. Diminished seed dispersal by elephants and high stem density are likely to reduce the recruitment of large trees, resulting in a more homogeneous forest structure and decreased carbon stocks. In sum, the loss of ecological services by forest elephants will likely transform Central African forests to be more like Neotropical forests, from which megafauna were extirpated thousands of years ago. Without intervention, as much as 96% of Central African forests will have modified species composition and structure as elephants are compressed into remaining protected areas. Stopping elephant poaching is an urgent first step to mitigating these effects, but long-term conservation will require land use planning that incorporates elephant habitat into forested landscapes that are being rapidly transformed by industrial agriculture and logging. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection

    Directory of Open Access Journals (Sweden)

    Himaman Winanda

    2011-05-01

    Full Text Available Abstract Background Parasites that manipulate host behavior can provide prominent examples of extended phenotypes: parasite genomes controlling host behavior. Here we focus on one of the most dramatic examples of behavioral manipulation, the death grip of ants infected by Ophiocordyceps fungi. We studied the interaction between O. unilateralis s.l. and its host ant Camponotus leonardi in a Thai rainforest, where infected ants descend from their canopy nests down to understory vegetation to bite into abaxial leaf veins before dying. Host mortality is concentrated in patches (graveyards where ants die on sapling leaves ca. 25 cm above the soil surface where conditions for parasite development are optimal. Here we address whether the sequence of ant behaviors leading to the final death grip can also be interpreted as parasite adaptations and describe some of the morphological changes inside the heads of infected workers that mediate the expression of the death grip phenotype. Results We found that infected ants behave as zombies and display predictable stereotypical behaviors of random rather than directional walking, and of repeated convulsions that make them fall down and thus precludes returning to the canopy. Transitions from erratic wandering to death grips on a leaf vein were abrupt and synchronized around solar noon. We show that the mandibles of ants penetrate deeply into vein tissue and that this is accompanied by extensive atrophy of the mandibular muscles. This lock-jaw means the ant will remain attached to the leaf after death. We further present histological data to show that a high density of single celled stages of the parasite within the head capsule of dying ants are likely to be responsible for this muscular atrophy. Conclusions Extended phenotypes in ants induced by fungal infections are a complex example of behavioral manipulation requiring coordinated changes of host behavior and morphology. Future work should address the

  20. Biosynthesis of zinc oxide nanoparticles using leaf extract of Calotropis gigantea: characterization and its evaluation on tree seedling growth in nursery stage

    Science.gov (United States)

    Chaudhuri, Sadhan Kumar; Malodia, Lalit

    2017-11-01

    Green synthesis of zinc oxide nanoparticles was carried out using Calotropis leaf extract with zinc acetate salt in the presence of 2 M NaOH. The combination of 200 mM zinc acetate salt and 15 ml of leaf extract was ideal for the synthesis of less than 20 nm size of highly monodisperse crystalline nanoparticles. Synthesized nanoparticles were characterized through UV-Vis spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), EDX (energy dispersive X-ray), and AFM (atomic force microscopy). Effects of biogenic zinc oxide (ZnO) nanoparticles on growth and development of tree seedlings in nursery stage were studied in open-air trenches. The UV-Vis absorption maxima showed peak near 350 nm, which is characteristic of ZnO nanoparticles. DLS data showed that single peak is at 11 nm (100%) and Polydispersity Index is 0.245. XRD analysis showed that these are highly crystalline ZnO nanoparticles having an average size of 10 nm. FTIR spectra were recorded to identify the biomolecules involved in the synthesis process, which showed absorption bands at 4307, 3390, 2825, 871, 439, and 420 cm-1. SEM images showed that the particles were spherical in nature. The presence of zinc and oxygen was confirmed by EDX and the atomic % of zinc and oxygen were 33.31 and 68.69, respectively. 2D and 3D images of ZnO nanoparticles were obtained by AFM studies, which indicated that these are monodisperse having size ranges between 1.5 and 8.5 nm. Significant enhancement of growth was observed in Neem ( Azadirachta indica), Karanj ( Pongamia pinnata), and Milkwood-pine ( Alstonia scholaris) seedlings in foliar spraying ZnO nanoparticles to nursery stage of tree seedlings. Out of the three treated saplings, Alstonia scholaris showed maximum height development.

  1. Where temperate meets tropical: Multi-factorial effects of elevated CO2, nitrogen enrichment, and competition on a mangrove-salt marsh community

    Science.gov (United States)

    McKee, K.L.; Rooth, J.E.

    2008-01-01

    Our understanding of how elevated CO2 and interactions with other factors will affect coastal plant communities is limited. Such information is particularly needed for transitional communities where major vegetation types converge. Tropical mangroves (Avicennia germinans) intergrade with temperate salt marshes (Spartina alterniflora) in the northern Gulf of Mexico, and this transitional community represents an important experimental system to test hypotheses about global change impacts on critical ecosystems. We examined the responses of A. germinans (C3) and S. alterniflora (C4), grown in monoculture and mixture in mesocosms for 18 months, to interactive effects of atmospheric CO2 and pore water nitrogen (N) concentrations typical of these marshes. A. germinans, grown without competition from S. alterniflora, increased final biomass (35%) under elevated CO2 treatment and higher N availability. Growth of A. germinans was severely curtailed, however, when grown in mixture with S. alterniflora, and enrichment with CO2 and N could not reverse this growth suppression. A field experiment using mangrove seedlings produced by CO2- and N-enriched trees confirmed that competition from S. alterniflora suppressed growth under natural conditions and further showed that herbivory greatly reduced survival of all seedlings. Thus, mangroves will not supplant marsh vegetation due to elevated CO2 alone, but instead will require changes in climate, environmental stress, or disturbance to alter the competitive balance between these species. However, where competition and herbivory are low, elevated CO2 may accelerate mangrove transition from the seedling to sapling stage and also increase above- and belowground production of existing mangrove stands, particularly in combination with higher soil N. ?? 2008 The Authors Journal compilation ?? 2008 Blackwell Publishing Ltd.

  2. Can gas exchange dynamics predict non-structural carbohydrate use under drought stress?

    Science.gov (United States)

    Kannenberg, S.; Phillips, R.

    2016-12-01

    A recent conceptual framework for understanding tree drought responses characterizes species along a continuum from isohydry to anisohydry, with theory predicting that isohydric and anisohydric trees should display different carbon (C) allocation patterns under drought conditions. We tested the hypothesis that the trade-offs inherent in the isohydry-anisohydry framework (i.e., C starvation vs. hydraulic failure) necessitate different allocation patterns to non-structural carbohydrates (NSCs), growth, and respiration. Specifically, we hypothesized that isohydric trees would decrease NSC stores and growth in the face of reduced incoming photoassimilate, whereas anisohydric trees would maintain assimilation, growth, and NSC pools due to decreased demand for stored metabolic C and enhanced osmoregulatory needs. To test this, we subjected saplings of Liriodendron tulipifera (an isohydric tree) and Quercus alba (an anisohydric tree) to a six week drought in the greenhouse, and measured assimilation, leaf water potential (midday and predawn), growth, leaf dark respiration and NSCs (both sugars and starch in aboveground and belowground tissues) in control and droughted plants. Overall, we confirmed that the isohydric and anisohydric species used NSCs differently during drought. In most tissues, both species had similar responses of NSCs to drought: starch NSCs were maintained or decreased while sugar NSCs tended to increase. Stem NSCs were a notable exception, as L. tulipifera decreased total NSC to almost zero while NSCs in Q. alba remained constant. This depletion of stem NSC in L. tulipifera was offset by increases in other tissues, however, resulting in no net change to total NSC during the drought. In contrast, Q. alba increased total NSC. Interestingly, Q. alba also decreased assimilation and growth, indicating a potential trade-off between NSC and biomass allocation. Our results show that NSCs in different tissues may have contrasting uses as storage or

  3. Stand dynamics and tree coexistence in an analytical structured model: the role of recruitment.

    Science.gov (United States)

    Angulo, Óscar; Bravo de la Parra, Rafael; López-Marcos, Juan C; Zavala, Miguel A

    2013-09-21

    Understanding the mechanisms of coexistence and niche partitioning in plant communities is a central question in ecology. Current theories of forest dynamics range between the so-called neutral theories which assume functional equivalence among coexisting species to forest simulators that explain species assemblages as the result of tradeoffs in species individual strategies at several ontogenetic stages. Progress in these questions has been hindered by the inherent difficulties of developing analytical size-structured models of stand dynamics. This precludes examination of the relative importance of each mechanism on tree coexistence. In previous simulation and analytical studies emphasis has been given to interspecific differences at the sapling stage, and less so to interspecific variation in seedling recruitment. In this study we develop a partial differential equation model of stand dynamics in which competition takes place at the recruitment stage. Species differ in their size-dependent growth rates and constant mortality rates. Recruitment is described as proportional to the basal area of conspecifics, to account for fecundity and seed supply per unit of basal area, and is corrected with a decreasing function of species specific basal area to account for competition. We first analyze conditions for population persistence in monospecific stands and second we investigate conditions of coexistence for two species. In the monospecific case we found a stationary stand structure based on an inequality between mortality rate and seed supply. In turn, intra-specific competition does not play any role on the asymptotic extinction or population persistence. In the two-species case we found that coexistence can be attained when the reciprocal negative effect on recruitment follows a given relation with respect to intraspecific competition. Specifically a tradeoff between recruitment potential (i.e. shade tolerance or predation avoidance) and fecundity or growth rate

  4. Tree size and light availability increase photochemical instead of non-photochemical capacities of Nothofagus nitida trees growing in an evergreen temperate rain forest.

    Science.gov (United States)

    Coopman, Rafael E; Briceño, Verónica F; Corcuera, Luis J; Reyes-Díaz, Marjorie; Alvarez, Daniela; Sáez, Katherine; García-Plazaola, José I; Alberdi, Miren; Bravo, León A

    2011-10-01

    Nothofagus nitida (Phil.) Krasser (Nothofagaceae) regenerates under the canopy in microsites protected from high light. Nonetheless, it is common to find older saplings in clear areas and adults as emergent trees of the Chilean evergreen forest. We hypothesized that this shade to sun transition in N. nitida is supported by an increase in photochemical and non-photochemical energy dissipation capacities of both photosystems in parallel with the increase in plant size and light availability. To dissect the relative contribution of light environment and plant developmental stage to these physiological responses, the photosynthetic performance of both photosystems was studied from the morpho-anatomical to the biochemical level in current-year leaves of N. nitida plants of different heights (ranging from 0.1 to 7 m) growing under contrasting light environments (integrated quantum flux (IQF) 5-40 mol m(-2). Tree height (TH) and light environment (IQF) independently increased the saturated electron transport rates of both photosystems, as well as leaf and palisade thickness, but non-photochemical energy flux, photoinhibition susceptibility, state transition capacity, and the contents of D1 and PsbS proteins were not affected by IQF and TH. Spongy mesophyll thickness and palisade cell diameter decreased with IQF and TH. A(max), light compensation and saturation points, Rubisco and nitrogen content (area basis) only increased with light environment (IQF), whereas dark respiration (R(d)) decreased slightly and relative chlorophyll content was higher in taller trees. Overall, the independent effects of more illuminated environment and tree height mainly increased the photochemical instead of the non-photochemical energy flux. Regardless of the photochemical increase with TH, carbon assimilation only significantly improved with higher IQF. Therefore it seems that mainly acclimation to the light environment supports the phenotypic transition of N. nitida from shade to

  5. Impacts of a spring heat wave on canopy processes in a northern hardwood forest.

    Science.gov (United States)

    Filewod, Ben; Thomas, Sean C

    2014-02-01

    Heat wave frequency, duration, and intensity are predicted to increase with global warming, but the potential impacts of short-term high temperature events on forest functioning remain virtually unstudied. We examined canopy processes in a forest in Central Ontario following 3 days of record-setting high temperatures (31–33 °C) that coincided with the peak in leaf expansion of dominant trees in late May 2010. Leaf area dynamics, leaf morphology, and leaf-level gas-exchange were compared to data from prior years of sampling (2002–2008) at the same site, focusing on Acer saccharum Marsh., the dominant tree in the region. Extensive shedding of partially expanded leaves was observed immediately following high temperature days, with A. saccharum losing ca. 25% of total leaf production but subsequently producing an unusual second flush of neoformed leaves. Both leaf losses and subsequent reflushing were highest in the upper canopy; however, retained preformed leaves and neoformed leaves showed reduced size, resulting in an overall decline in end-of-season leaf area index of 64% in A. saccharum, and 16% in the entire forest. Saplings showed lower leaf losses, but also a lower capacity to reflush relative to mature trees. Both surviving preformed and neoformed leaves had severely depressed photosynthetic capacity early in the summer of 2010, but largely regained photosynthetic competence by the end of the growing season. These results indicate that even short-term heat waves can have severe impacts in northern forests, and suggest a particular vulnerability to high temperatures during the spring period of leaf expansion in temperate deciduous forests.

  6. A cost-benefit analysis of acclimation to low irradiance in tropical rainforest tree seedlings: leaf life span and payback time for leaf deployment.

    Science.gov (United States)

    Coste, Sabrina; Roggy, Jean-Christophe; Schimann, Heidy; Epron, Daniel; Dreyer, Erwin

    2011-07-01

    The maintenance in the long run of a positive carbon balance under very low irradiance is a prerequisite for survival of tree seedlings below the canopy or in small gaps in a tropical rainforest. To provide a quantitative basis for this assumption, experiments were carried out to determine whether construction cost (CC) and payback time for leaves and support structures, as well as leaf life span (i) differ among species and (ii) display an irradiance-elicited plasticity. Experiments were also conducted to determine whether leaf life span correlates to CC and payback time and is close to the optimal longevity derived from an optimization model. Saplings from 13 tropical tree species were grown under three levels of irradiance. Specific-CC was computed, as well as CC scaled to leaf area at the metamer level. Photosynthesis was recorded over the leaf life span. Payback time was derived from CC and a simple photosynthesis model. Specific-CC displayed only little interspecific variability and irradiance-elicited plasticity, in contrast to CC scaled to leaf area. Leaf life span ranged from 4 months to >26 months among species, and was longest in seedlings grown under lowest irradiance. It was always much longer than payback time, even under the lowest irradiance. Leaves were shed when their photosynthesis had reached very low values, in contrast to what was predicted by an optimality model. The species ranking for the different traits was stable across irradiance treatments. The two pioneer species always displayed the smallest CC, leaf life span, and payback time. All species displayed a similar large irradiance-elicited plasticity.

  7. Effects of Land-Use Change on Under Storey Species Composition and Distribution in a Tropical Rainforest

    Directory of Open Access Journals (Sweden)

    Anthony Ifechukwude ODIWE

    2012-02-01

    Full Text Available The forest land�s conversion into tree crops plantations plays a major role in the loss of biodiversity. Therefore, understanding the impacts of land-use change on species diversity is very critical for ecosystem functioning and stability. This study was carried out to evaluate the effect of land-use changes on under storey species diversity in the Theobroma cacao and Citrus sinensis plantations. Two, 25 m � 25 m plots were sampled in each plantation and a nearby undisturbed secondary rainforest for comparison. The diameters (dbh-1.3 m of all trees at breast height >10 cm were measured in each plot. Five line transect were systematically laid and a quadrat of 50 cm � 50 cm placed at every 1 m point to identify the under storey species (herbaceous, shrubs, tree saplings and climbers present in each plot. Percentage canopy, species diversity using Shannon-Wiener, Simpson�s index and Evenness were determined, while species similarity was determined using the Jaccard�s similarity index. Results indicate that woody basal area and stem density in Theobroma cacao were significantly (P<0.05 higher than the Citrus sinensis plantation. A total number of 25, 27, and 14 under storey species distributed in 16, 19 and 11 families were found in Theobroma cacao, Citrus sinensis plantations and secondary forest respectively. Panicum maximum and Axonopus compressus were the dominant grasses in the Theobroma cacao and Citrus sinensis plantations respectively. The percentage canopy cover was significantly (P<0.05 higher in the secondary forest than the plantations. The land use modification has significantly increased the under storey species composition.

  8. Forest structure of oak plantations after silvicultural treatment to enhance habitat for wildlife

    Science.gov (United States)

    Twedt, Daniel J.; Phillip, Cherrie-Lee P.; Guilfoyle, Michael P.; Wilson, R. Randy; Schweitzer, Callie Jo; Clatterbuck, Wayne K.; Oswalt, Christopher M.

    2016-01-01

    During the past 30 years, thousands of hectares of oak-dominated bottomland hardwood plantations have been planted on agricultural fields in the Mississippi Alluvial Valley. Many of these plantations now have closed canopies and sparse understories. Silvicultural treatments could create a more heterogeneous forest structure, with canopy gaps and increased understory vegetation for wildlife. Lack of volume sufficient for commercial harvest in hardwood plantations has impeded treatments, but demand for woody biomass for energy production may provide a viable means to introduce disturbance beneficial for wildlife. We assessed forest structure in response to prescribed pre-commercial perturbations in hardwood plantations resulting from silvicultural treatments: 1) row thinning by felling every fourth planted row; 2) multiple patch cuts with canopy gaps of treatments, and an untreated control, were applied to oak plantations (20 - 30 years post-planting) on three National Wildlife Refuges (Cache River, AR; Grand Cote, LA; and Yazoo, MS) during summer 2010. We sampled habitat using fixed-radius plots in 2009 (pre-treatment) and in 2012 (post-treatment) at random locations. Retained basal area was least in diagonal corridor treatments but had greater variance in patch-cut treatments. All treatments increased canopy openness and the volume of coarse woody debris. Occurrence of birds using early successional habitats was greater on sites treated with patch cuts and diagonal intersections. Canopy openings on row-thinned stands are being filled by lateral crown growth of retained trees whereas patch cut and diagonal intersection gaps appear likely to be filled by regenerating saplings.

  9. Postfire seedling dynamics and performance in Pinus halepensis Mill. populations

    Science.gov (United States)

    Daskalakou, Evangelia N.; Thanos, Costas A.

    2010-09-01

    Postfire dynamics of Aleppo pine seedling density, survival and growth were assessed in five burned forests of Attica, Greece (Stamata, Villia, Avlona, Kapandriti and Agios Stefanos) through the establishment of permanent experimental plots. All emerging seedlings were tagged and their survival and growth monitored at regular intervals. Seedling density dynamics show an initial, steep increase (to maximum values 2.9-4.6 seedlings m -2) followed by a gradual decrease that levels off at the second and third postfire year (1.3-3.0 seedlings m -2); similarly, postfire seedling survival more or less stabilised at 30-50%, 2-3 years after fire. On the basis of density and mortality trends as well as relevant bibliographic data, it is predicted that very dense, mature forests (10.000 trees ha -1 or more) will be reinstated within 15-20 years. During the first 5-7 postfire years, seedling/sapling annual height followed linear trends with various yearly rates, ranging mostly between 8 and 15 cm (and 27-30 cm in two exceptional, fast growing cases). Within an individual growth season, seedling height dynamics were found to follow sigmoid curves with growth increment peaks in mid-spring. The time (on a monthly basis) of seedling emergence did not affect seedling growth or survival. On the other hand, for the first time under natural conditions, it has been shown that cotyledon number per seedling, an indirect measure of both seed size and initial photosynthetic capacity, significantly affected seedling survival but not growth. Seedlings bearing a higher number of cotyledons, presumably derived from larger seeds, showed greater survival at the end of the first postfire year than seedlings with fewer cotyledons. A postfire selective pressure, favouring large seed size, is postulated to counteract with a contrasting one, which favours small seed size, expressed during fire-free conditions.

  10. Kandungan Nitrat dan Fosfat Sedimen serta Keterkaitannya dengan Kerapatan Mangrove di Kawasan Mertasari di Aliran Sungai TPA Suwung Denpasar, Bali

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    Ni Nyoman Desi Kusuma Dewi

    2017-06-01

    Full Text Available Mangrove is a green plants tolerant of salt water, which grows mainly along the sheltered coastal areas, especially along the bay or in estuaries. Final Disposal (TPA Rubbish Suwung which located in the village Pedungan South Denpasar District is the rubbish dumps originating from the city of Denpasar and Badung. There is a natural mangrove vegetation in the river TPA. Mertsari area which located in the village of Sanur, West Denpasar District is a mangrove planting area and tourism destination on the Mertasari Beach. The purpose of this research are as follows: (1 To identify the content of nitrate and phosphate in mangrove sediments, (2 To determine the density of mangrove in Region Mertasari and TPA Suwung River Flow and (3 To describe the mangrove density is linkage with nitrate and phosphate mangrove sediments. The method used on this research is linear regression. Nitrate and phosphate sediments of mangroves in TPA Suwung River Flow and Region Mertasari range of 0.04 ppm - 79.034 ppm. The average density results of the mangrove tree level, saplings and seedlings in different locations ranged 0.01 ind / m2 - 0.32 ind / m2. The river's flow TPA Suwung produce a simple linear regression calculation of nitrate mangrove sediments density y = -0,002x + 0,288 (R2 10,1 %, and the calculation of the density sedimentary  phosphate mangrove produce y = 0,007x + 0,125  (R2 6,1 %. The results of simple linear regression calculation of nitrate sediments density Mertasari mangrove area is y = -0,002x+ 0,537  R2 = 4,7%, and the calculation of the density sedimentary  phosphate mangrove produce y = -0,038x + 0,777 (R2 63,7 %.

  11. Movement patterns of riparian small mammals during predictable floodplain inundation

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    Andersen, D.C.; Wilson, K.R.; Miller, M.S.; Falck, M.

    2000-01-01

    We monitored movements of small mammals resident on floodplains susceptible to spring floods to assess whether and how these animals respond to habitat inundation. The 2 floodplains were associated with 6th order river segments in a semiarid landscape; each was predictably inundated each year as snowmelt progressed in headwater areas of the Rocky Mountains. Data from live trapping, radiotelemetry, and microtopographic surveys indicated that Peromyscus maniculatus, Microtus montanus, and Dipodomys ordii showed different responses to inundation, but all reflected a common tendency to remain in the original home range until “forced” to leave. The reluctance of Dipodomys ordii to abandon the home burrow often resulted in death in situ, whereas individual P. maniculatus and M. montanus moved to nearby higher ground but not necessarily toward upland. This behavior could lead to occupancy of an island that disappeared as floodwaters rose. Peromyscus maniculatus climbed into sapling cottonwood, but the quality of such arboreal refuges was unclear. We found only weak support for the hypothesis that displacement was temporary; most floodplain residents, including P. maniculatus, disappeared over the flood period. No secondary effect from flooding on adjacent upland small-mammal assemblages was detected. Our data suggest populations of facultatively riparian, nonarboreal small mammals such as M. montanus and D. ordii generally experience habitat inundation as a catastrophy. Terrestrial species capable of using an arboreal refuge, such as P. maniculatus, face a more variable risk, determined in part by timing and duration of the flood event. River regulation can affect both sets of risks.

  12. Differential responses of C3 and CAM native Brazilian plant species to a SO2- and SPMFe-contaminated Restinga.

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    da Silva, Luzimar Campos; de Araújo, Talita Oliveira; Martinez, Carlos Alberto; de Almeida Lobo, Francisco; Azevedo, Aristéa Alves; Oliva, Marco Antonio

    2015-09-01

    Aiming to evaluate responses in terms of growth rates, physiological parameters, and degree of sensitivity to SO2 and SPMFe in Eugenia uniflora L. (Myrtaceae, a C3 species) and Clusia hilariana Schlecht (Clusiaceae, a CAM species); saplings were exposed to emissions from a pelletizing factory for 7 months. The species were distributed along a transect (200, 500, 800, 1400, and 1700 m away from the emission source), and analyses were performed after 71, 118, and 211 days of exposure to the pollutants. E. uniflora received higher superficial deposition of particulate iron. The highest total iron foliar contents were observed 200 m away from the emission source in both plant species, while the highest total sulfur foliar contents were observed 200 m away in C. hilariana and 800 m away in E. uniflora. E. uniflora presented decreased values of height growth rate, number of necrotic leaves, chlorophyll analysis (SPAD index) and transpiration, in relation to the distances from the emission source. C. hilariana showed decreased values of height growth rate, number of leaves, number of necrotic leaves, total ionic permeability, stomatal conductance, transpiration, net CO2 assimilation, and total dry matter, in relation to distances from the emission source. In relation to the days of exposure, both species presented increased number of necrotic leaves and foliar phytotoxicity index, and decreased values in the chlorophyll analysis. The two native plant species, both of which occur in the Brazilian Restinga, showed damage when exposed to emissions from an iron ore pelletizing factory. C. hilariana was considered the most sensitive species due to the decreased values in a higher number of variables after exposition.

  13. The effect of grazing exclusion over time on structure, biodiversity, and regeneration of high nature value farmland ecosystems in Europe.

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    Listopad, Claudia M C S; Köbel, Melanie; Príncipe, Adriana; Gonçalves, Paula; Branquinho, Cristina

    2018-01-01

    Climate change and increasing socio-economic pressure is placing many ecosystems of high ecological and economic value at risk. This is particularly urgent in dryland ecosystems, such as the montado, a multifunctional savannah-like system heavily modeled by grazing. There is still an ongoing debate about the trade-offs between livestock grazing and the potential for ecosystem regeneration. While it is consensual that overgrazing hinders the development of the shrubs and trees in this system, the effects of undergrazing or grazing exclusion are unclear. This study provides the unique opportunity to study the impact of grazing on compositional and structural biodiversity by examining the ecological chronosequence in a long-term ecological research site, located in Portugal, where grazing exclusion was controlled for over 15years. As the threat of intensification persists, even in areas where climate shifts are evident, there is a critical need to understand if and how the montado might recover by removing grazing pressure. We evaluate succession on structural and compositional diversity after grazing pressure is removed from the landscape at 5, 10, and 15years post-cattle exclusion and contrast it with currently grazed plots. A LiDAR-derived structural diversity index (LHDI), a surrogate of ecosystem structure and function first developed for the pine-grassland woodland systems, is used to quantify the impact of grazing exclusion on structure and natural regeneration. The distribution of the vegetation, particularly those of the herbaceous and shrub strata (>10≤150cm), presents statistically significant changes. The LHDI closely mimics the compositional biodiversity of the shrubs, with an increase in diversity with increased years without grazing. Under present climate conditions, both shrub regeneration and the establishment of tree saplings were strongly promoted by grazing exclusion, which has important management implications for the long-term sustainability of

  14. Size-mediated foliar response to ozone in black cherry trees.

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    Fredericksen, T S; Skelly, J M; Steiner, K C; Kolb, T E; Kouterick, K B

    1996-01-01

    Local ozone concentration and visible foliar injury were measured over the 1994 growing season on open-grown black cherry (Prunus serotina Ehrh.) trees of varying size (age) within forest stands and adjacent openings at a site in north-central Pennsylvania. Relationships were determined between visible ozone injury and ozone exposure, as well as calculated between injury and ozone uptake expressed as the product of stomatal conductance and ozone concentration. In addition, simultaneous measurements of visible symptoms and leaf gas exchange were also conducted to determine the correlation between visible and physiological injury and ozone exposure. By September, the amount of leaf area affected by visible foliar ozone injury was greatest for seedlings (46%), followed by canopy trees (20%) and saplings (15%). A large amount of variability in foliar ozone symptom expression was observed among trees within a size class. Sum40 and Sum60 (ozone concentration > 40 and > 60 nl liter(-1)) cumulative exposure statistics were the most meaningful indices for interpretation of foliar injury response. Seedlings were apparently more sensitive to ozone injury than larger trees because their higher rates of stomatal conductance resulted in higher rates of ozone uptake. Seedlings also had higher rates of early leaf abscission than larger trees with an average of nearly 30% of the leaves on a shoot abscised by 1 September compared to approximately 5% for larger trees. However, per unit ozone uptake into the leaf, larger trees exhibited larger amounts of foliar injury. The amount of visible foliar injury was negatively correlated (r(2) = 0.82) with net photosynthetic rates, but was not related to stomatal conductance. Net photosynthesis and stomatal conductance thus became uncoupled at high levels of visible foliar injury.

  15. Gas exchange, leaf structure and nitrogen in contrasting successional tree species growing in open and understory sites during a drought.

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    Abrams, M D; Mostoller, S A

    1995-06-01

    Seasonal ecophysiology, leaf structure and nitrogen were measured in saplings of early (Populus grandidentata Michx. and Prunus serotina J.F. Ehrh.), middle (Fraxinus americana L. and Carya tomentosa Nutt.) and late (Acer rubrum L. and Cornus florida L.) successional tree species during severe drought on adjacent open and understory sites in central Pennsylvania, USA. Area-based net photosynthesis (A) and leaf conductance to water vapor diffusion (g(wv)) varied by site and species and were highest in open growing plants and early successional species at both the open and understory sites. In response to the period of maximum drought, both sunfleck and sun leaves of the early successional species exhibited smaller decreases in A than leaves of the other species. Shaded understory leaves of all species were more susceptible to drought than sun leaves and had negative midday A values during the middle and later growing season. Shaded understory leaves also displayed a reduced photosynthetic light response during the peak drought period. Sun leaves were thicker and had a greater mass per area (LMA) and nitrogen (N) content than shaded leaves, and early and middle successional species had higher N contents and concentrations than late successional species. In both sunfleck and sun leaves, seasonal A was positively related to predawn leaf Psi, g(wv), LMA and N, and was negatively related to vapor pressure deficit, midday leaf Psi and internal CO(2). Although a significant amount of plasticity occurred in all species for most gas exchange and leaf structural parameters, middle successional species exhibited the largest degree of phenotypic plasticity between open and understory plants.

  16. Individual traits as determinants of time to death under extreme drought in Pinus sylvestris L.

    Science.gov (United States)

    Garcia-Forner, Núria; Sala, Anna; Biel, Carme; Savé, Robert; Martínez-Vilalta, Jordi

    2016-10-01

    Plants exhibit a variety of drought responses involving multiple interacting traits and processes, which makes predictions of drought survival challenging. Careful evaluation of responses within species, where individuals share broadly similar drought resistance strategies, can provide insight into the relative importance of different traits and processes. We subjected Pinus sylvestris L. saplings to extreme drought (no watering) leading to death in a greenhouse to (i) determine the relative effect of predisposing factors and responses to drought on survival time, (ii) identify and rank the importance of key predictors of time to death and (iii) compare individual characteristics of dead and surviving trees sampled concurrently. Time until death varied over 3 months among individual trees (from 29 to 147 days). Survival time was best predicted (higher explained variance and impact on the median survival time) by variables related to carbon uptake and carbon/water economy before and during drought. Trees with higher concentrations of monosaccharides before the beginning of the drought treatment and with higher assimilation rates prior to and during the treatment survived longer (median survival time increased 25-70 days), even at the expense of higher water loss. Dead trees exhibited less than half the amount of nonstructural carbohydrates (NSCs) in branches, stem and relative to surviving trees sampled concurrently. Overall, our results indicate that the maintenance of carbon assimilation to prevent acute depletion of NSC content above some critical level appears to be the main factor explaining survival time of P. sylvestris trees under extreme drought. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection

    Science.gov (United States)

    2011-01-01

    Background Parasites that manipulate host behavior can provide prominent examples of extended phenotypes: parasite genomes controlling host behavior. Here we focus on one of the most dramatic examples of behavioral manipulation, the death grip of ants infected by Ophiocordyceps fungi. We studied the interaction between O. unilateralis s.l. and its host ant Camponotus leonardi in a Thai rainforest, where infected ants descend from their canopy nests down to understory vegetation to bite into abaxial leaf veins before dying. Host mortality is concentrated in patches (graveyards) where ants die on sapling leaves ca. 25 cm above the soil surface where conditions for parasite development are optimal. Here we address whether the sequence of ant behaviors leading to the final death grip can also be interpreted as parasite adaptations and describe some of the morphological changes inside the heads of infected workers that mediate the expression of the death grip phenotype. Results We found that infected ants behave as zombies and display predictable stereotypical behaviors of random rather than directional walking, and of repeated convulsions that make them fall down and thus precludes returning to the canopy. Transitions from erratic wandering to death grips on a leaf vein were abrupt and synchronized around solar noon. We show that the mandibles of ants penetrate deeply into vein tissue and that this is accompanied by extensive atrophy of the mandibular muscles. This lock-jaw means the ant will remain attached to the leaf after death. We further present histological data to show that a high density of single celled stages of the parasite within the head capsule of dying ants are likely to be responsible for this muscular atrophy. Conclusions Extended phenotypes in ants induced by fungal infections are a complex example of behavioral manipulation requiring coordinated changes of host behavior and morphology. Future work should address the genetic basis of such extended

  18. Differential responses of herbivores and herbivory to management in temperate European beech.

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    Martin M Gossner

    Full Text Available Forest management not only affects biodiversity but also might alter ecosystem processes mediated by the organisms, i.e. herbivory the removal of plant biomass by plant-eating insects and other arthropod groups. Aiming at revealing general relationships between forest management and herbivory we investigated aboveground arthropod herbivory in 105 plots dominated by European beech in three different regions in Germany in the sun-exposed canopy of mature beech trees and on beech saplings in the understorey. We separately assessed damage by different guilds of herbivores, i.e. chewing, sucking and scraping herbivores, gall-forming insects and mites, and leaf-mining insects. We asked whether herbivory differs among different forest management regimes (unmanaged, uneven-aged managed, even-aged managed and among age-classes within even-aged forests. We further tested for consistency of relationships between regions, strata and herbivore guilds. On average, almost 80% of beech leaves showed herbivory damage, and about 6% of leaf area was consumed. Chewing damage was most common, whereas leaf sucking and scraping damage were very rare. Damage was generally greater in the canopy than in the understorey, in particular for chewing and scraping damage, and the occurrence of mines. There was little difference in herbivory among differently managed forests and the effects of management on damage differed among regions, strata and damage types. Covariates such as wood volume, tree density and plant diversity weakly influenced herbivory, and effects differed between herbivory types. We conclude that despite of the relatively low number of species attacking beech; arthropod herbivory on beech is generally high. We further conclude that responses of herbivory to forest management are multifaceted and environmental factors such as forest structure variables affecting in particular microclimatic conditions are more likely to explain the variability in herbivory

  19. Insect attraction to herbivore-induced beech volatiles under different forest management regimes.

    Science.gov (United States)

    Gossner, Martin M; Weisser, Wolfgang W; Gershenzon, Jonathan; Unsicker, Sybille B

    2014-10-01

    Insect herbivore enemies such as parasitoids and predators are important in controlling herbivore pests. From agricultural systems we know that land-use intensification can negatively impact biological control as an important ecosystem service. The aim of our study was to investigate the importance of management regime for natural enemy pressure and biological control possibilities in forests dominated by European beech. We hypothesize that the volatile blend released from herbivore-infested beech trees functions as a signal, attracting parasitoids and herbivore enemies. Furthermore, we hypothesize that forest management regime influences the composition of species attracted by these herbivore-induced beech volatiles. We installed flight-interception traps next to Lymantria dispar caterpillar-infested young beech trees releasing herbivore-induced volatiles and next to non-infested control trees. Significantly more parasitoids were captured next to caterpillar-infested trees compared to non-infested controls, irrespective of forest type. However, the composition of the trophic guilds in the traps did vary in response to forest management regime. While the proportion of chewing insects was highest in non-managed forests, the proportion of sucking insects peaked in forests with low management and of parasitoids in young, highly managed, forest stands. Neither the number of naturally occurring beech saplings nor herbivory levels in the proximity of our experiment affected the abundance and diversity of parasitoids caught. Our data show that herbivore-induced beech volatiles attract herbivore enemies under field conditions. They further suggest that differences in the structural complexity of forests as a consequence of management regime only play a minor role in parasitoid activity and thus in indirect tree defense.

  20. Effect of the internet commerce on dispersal modes of invasive alien species.

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    Magdalena Lenda

    Full Text Available The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal.