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Sample records for camaldulenis tree leaves

  1. Uptake of perfluoroalkyl acids in the leaves of coniferous and deciduous broad-leaved trees.

    Science.gov (United States)

    Zhang, Huanhuan; Liu, Wei; He, Xin; Wang, Yu; Zhang, Qian

    2015-07-01

    Analytical methods for determining perfluoroalkyl acids (PFAAs) in leaves were developed to quantify a suite of analytes in both coniferous and deciduous broad-leaved trees. Sodium hydroxide-methanol and solid-phase extraction was selected as the extracting and cleanup strategy for PFAA analysis. Ten perfluorocarboxylic acids (PFCAs) and 4 perfluorosulfonic acids (PFSAs) were monitored in 7 kinds of leaves grown in the urban areas of Dalian, China. The results show that coniferous tree leaves take up more PFAAs than broad-leaved tree leaves, with the highest amount of 150 ng/g in pine needles. Leaf PFCA levels were much higher than PFSAs level. Short carbon-chain PFCAs with 3 to 6 perfluorinated carbons account for approximately 40% to 80% of the total leaf PFAAs, where uptake decreased with increasing carbon chain length. Temporal observation of leaf PFAAs revealed no significant variation of concentrations in the leaves over a weekly interval and the absence of significant seasonal change in pine needles and sophora. The present study provides some evidence for the accumulation of PFAAs in leaves, which is valuable for understanding their environmental behavior and the development of alternative bioindicator.

  2. Seasonality of nutrients in leaves and fruits of apple trees

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    Nachtigall Gilmar Ribeiro

    2006-01-01

    Full Text Available The nutrient accumulation curves of apple trees are good indicators of plant nutrient demand for each developmental stage. They are also a useful tool to evaluate orchard nutritional status and to estimate the amount of soil nutrient removal. This research aimed at evaluating the seasonality of nutrients in commercial apple orchards during the agricultural years of 1999, 2000, and 2001. Therefore, apple tree leaves and fruits of three cultivars 'Gala', 'Golden Delicious' and 'Fuji' were weekly collected and evaluated for fresh and dry matter, fruit diameter and macronutrient (N, P, K, Ca and Mg and micronutrient (B, Cu, Fe, Mn, and Zn concentrations. Leaf and fruit sampling started one or two weeks after full bloom, depending on the cultivar, and ended at fruit harvest or four weeks later (in the case of leaf sampling. In general, leaf concentrations of N, P, K, Cu, and B decreased; Ca increased; and Mg, Fe, Mn, and Zn did vary significantly along the plant vegetative cycle. In fruits, the initial nutrient concentrations decreased quickly, undergoing slow and continuous decreases and then remaining almost constant until the end of fruit maturation, indicating nutrient dilution, once the total nutrient accumulation increased gradually with fruit growth. Potassium was the nutrient present in highest quantities in apple tree fruits and thus, the most removed from the soil.

  3. Stomatal control of water use in olive tree leaves

    OpenAIRE

    Fernández Luque, José Enrique; Moreno Lucas, Félix; Girón Moreno, Ignacio F.; Blázquez, O. M.

    1997-01-01

    Little is known about the strategies used by olive trees to overcome the long dry periods typical of the areas where they are cropped. This makes it difficult to optimize the water supply in orchards. To study the control of water consumption by olive trees, measurements of leaf water potential (Ψ) and stomatal conductance to H2O (g) were made on 26-year-old Manzanillo olive trees under three irrigation treatments. The first treatment provided enough water to cover the crop water demand, the ...

  4. Air pollution survey in Rome using magnetic properties of tree leaves

    Science.gov (United States)

    Moreno, E.; Sagnotti, L.; Winkler, A.; Dinarès Turell, J.; Cascella, A.

    2003-04-01

    We present the results of a biomonitoring study of air pollution in Rome based on the magnetic properties of tree leaves from Platanus sp. and Quercus Ilex. A Platanus sp. sampling campaign was effectuated in October 2001 and 5 Quercus Ilex monthly sampling campaigns from April to August 2002. Comparison between different tree species from the same location pointed out that leaves of the evergreen oak Quercus Ilex, with an average life-span of 3 years, present much higher magnetic intensities that leaves from Platanus sp. and other deciduous species common in Rome, suggesting that leaves accumulate magnetic pollutants during their whole life-span. Low-coercivity minerals of sub-micron size constantly dominate the magnetic fraction of the dusts accumulated on leaves. However, concentration and size of magnetic particles on leaves appear to be controlled by vehicular traffic emissions. In fact, distribution maps of magnetic susceptibility and isothermal remanence (IRM) from leaves collected in selected study areas in the south of Rome show distinct patterns that follow the distribution of green areas and main roads. High concentration and relatively larger grain-sizes of magnetic particles were observed in trees located along roads with high vehicle traffic and in the vicinity of railways. We found that the values of susceptibility and IRM along the main roads were about 10 times higher than in parks. Moreover, we also observed a decrease in concentration and grain size of magnetic particles with distance from the roadside, reinforcing the conclusion that the main sources of fine magnetic dusts adsorbed and deposited on the tree leaves are vehicle emissions. The results indicate that a magnetic survey of tree leaves, which is relatively rapid and inexpensive, may be used in addition to the classical air quality monitoring systems to identify and delineate high-polluted areas in urban environments.

  5. Assessment of Tree Leaves Flakes Mixed with Crude Glycerol as a Bioenergy Source

    Science.gov (United States)

    Hilal-AlNaqbi, Ali; Al-Omari, Salah B.; Selim, Mohamed Y. E.

    2016-01-01

    The gasification and combustion of dry tree leaves and the cogasification of dry tree leaves soaking crude glycerol were studied experimentally. An updraft fixed bed gasification and combustion system was built. The operation was conducted at different air to fuel ratios. Results show more stable combustion and more effective heat transfer to furnace walls for the cases when tree leaves flakes are mixed with 20 percent (on mass basis) of crude glycerol, as compared with the case when only dry tree leaves are used as fuel. TGA analysis was also conducted for the two fuels used under both air and nitrogen environments. For the crude glycerol, four phases of pyrolysis and gasification were noticed under either of the two surrounding gaseous media (air or nitrogen). For the dry tree leaves, the pyrolysis under nitrogen shows only a simple smooth pyrolysis and gasification curve without showing the different distinct phases that were otherwise identified when the pyrolysis is conducted under air environment. Moreover, the air TGA results lead to more gasification due to the char oxidation at high temperatures. DTG results are also presented and discussed. PMID:27413749

  6. Assessment of Tree Leaves Flakes Mixed with Crude Glycerol as a Bioenergy Source

    Directory of Open Access Journals (Sweden)

    Ali Hilal-AlNaqbi

    2016-01-01

    Full Text Available The gasification and combustion of dry tree leaves and the cogasification of dry tree leaves soaking crude glycerol were studied experimentally. An updraft fixed bed gasification and combustion system was built. The operation was conducted at different air to fuel ratios. Results show more stable combustion and more effective heat transfer to furnace walls for the cases when tree leaves flakes are mixed with 20 percent (on mass basis of crude glycerol, as compared with the case when only dry tree leaves are used as fuel. TGA analysis was also conducted for the two fuels used under both air and nitrogen environments. For the crude glycerol, four phases of pyrolysis and gasification were noticed under either of the two surrounding gaseous media (air or nitrogen. For the dry tree leaves, the pyrolysis under nitrogen shows only a simple smooth pyrolysis and gasification curve without showing the different distinct phases that were otherwise identified when the pyrolysis is conducted under air environment. Moreover, the air TGA results lead to more gasification due to the char oxidation at high temperatures. DTG results are also presented and discussed.

  7. Biomonitoring of traffic air pollution in Rome using magnetic properties of tree leaves

    Science.gov (United States)

    Moreno, Eva; Sagnotti, Leonardo; Dinarès-Turell, Jaume; Winkler, Aldo; Cascella, Antonio

    We report a biomonitoring study of air pollution in Rome based on the magnetic properties of tree leaves. In a first step, magnetic properties of leaves from different tree species from the same location were compared. It was observed that leaves of evergreen species, like Quercus ilex, present much higher magnetic intensities than those of deciduous species, like Platanus sp., suggesting that leaves accumulate magnetic pollutants during their whole lifespan. In a second step, leaves from Q. ilex and Platanus sp. trees, both very common in Rome, have been used to monitor traffic emission pollution in two different periods. A Platanus sp. sampling campaign was undertaken in October 2001, at the end of the seasonal vegetational cycle, and 5 Q. ilex monthly sampling campaigns from April to August 2002. The strong difference observed in the magnetic susceptibility from leaves collected in green areas and roads allowed the realization of detailed pollution distribution maps from the south of Rome. Magnetic properties indicate that high concentrations and relatively larger grain-sizes of magnetic particles are observed in trees located along roads with high vehicle traffic and in the vicinity of railways. The decrease in concentration and grain size of magnetic particles with distance from the roadside confirms that magnetic properties of leaves are related to air pollution from vehicle emissions. The results indicate that a magnetic survey of tree leaves, which is relatively rapid and inexpensive, may be used in addition to the classical air quality monitoring systems to identify and delineate high-polluted areas in urban environments.

  8. Structural analysis of Castanea sativa Mill. leaves from different regions in the tree top

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    Teresa Maria Pinto

    2011-02-01

    Full Text Available The aim of this work was to perform the histological characterization of the C. sativa leaves of three Portuguese cultivars to establish comparison among the leaves of the different quadrants in accord and with the cardinal points of the tree top and among different cultivars of this species, using light microscopy (OM and scanning electron microscopy (SEM. Measurements were also carried out for the leaf tissue thickness, stomatal density, leaf area in the four tree top quadrants. The leaves turned to the North had lesser thickness of mesophyll mainly due to lower amount of palisade parenchyma. The stomatal density was significantly lower in these leaves, unlike the leaf area that has the highest expression.

  9. Dynamics of nitrogen nutrition of coexisting dominant trees in mixed broad-leaved/Korean pine forest

    Institute of Scientific and Technical Information of China (English)

    Li Yuwen

    1999-01-01

    Chemical analysis of ammonium, nitrate and total nitrogen in tree leaves and roots and an in-vivo bioassay for nitrate reductase activity (NRA) were used to monitor the seasonal variations in nitrogen assimilation among four coexisting dominant tree species, including Pinus koraiensis, Ti/ia amurensis, Fraxinus mandshurica and Acer mono, in a virgin mixed broad-leaved/Korean pine (Pinus koraiensis) forest. The soil study included individual horizons of L+F (0-5 cm), Ah (5-11 cm) and Aw (11-25 cm). All four species had nitrate and ammonium in their roots and leaves, and also NRA in leaves. This indicated that these coexisting species were adapted to ammonium + nitrate nutrition. A negative correlation existed between nitrate use and ammonium use. Ammonium concentration was higher than that of nitrate in tree leaves and roots, and also in soils, which indicated climax woody species had a relative preference for ammonium nutrition. There was a positive relationship between tree nitrogen nutrition use and soil nitrogen nutrient supply. Utilization of ammonium and nitrate as well as the seasonal patterns differed significantly between the species. Peaks of ammonium, nitrate, NRA and total nitrogen in one species were therefore not necessarily synchronous with peaks in other species, and which indicated a species-specific seasonal use of nitrogen. The species-specific temporal differentiation in nitrogen use might reduce the competition between co-existing species and may be an important mechanism promoting stability of virgin mixed broad-leaved∥Korean pine forest.

  10. Weather and Climate on the Reliability of Enviromagnetic Studies of Tree Leaves in Air Pollution Monitoring

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    Rey, D.; Rodríguez-Germade, I.; Mohamed Falcon, K. J.; Rubio, B.; Garcia, A.

    2014-12-01

    Monthly monitoring of the magnetic properties of Platanus hispanica tree leaves to assess atmospheric pollution in Madrid (Spain) and its suburban town of Pozuelo de Alarcon showed anthropogenic time-related klf enhancement of tree leaves. We established a significant correlation between metal concentration (leaching) in the leaves with Klf and IRM1T. This relationship was not as high as those found in other studies carried out on airborne dust, sediments and soils. Further analyses pointed out that local humidity played a dual roll, controlling availability of airborne lithogenic dust and the incorporation of trace metals in the leaf tissue, modulating the magnetic enhancement. Further to these findings, the comparison between cities of different climatic regimes showed that air humidity is the major factor controlling the interaction of the atmosphere and tree leaves, thus their magnetic properties. The relative influence of pollutants, lithogenic dust and biological effects depends not only on local meteorology but also on climate. Their influence should be most seriously considered to design methodological approaches that are appropriate to the environmental characteristics of each study area, if the magnetic properties of tree leaves are intended as an atmospheric pollution-monitoring tool.

  11. Trace element content in urban tree leaves and SEM-EDAX characterization of deposited particles

    OpenAIRE

    Tomašević Milica; Aničić Mira

    2010-01-01

    Leaves of common deciduous trees: Aesculus hippocastanum and Tilia spp. from three parks within the urban area of Belgrade (Serbia) were studied as biomonitors of trace elements (V, Cr, Fe, Ni, Cu, Zn, As, Cd, and Pb) air pollution. Using a scanning SEM-EDAX, the size, size distribution, morphology and chemical composition of individual particles were examined on adaxial and abaxial surfaces of the leaves. Morphological and chemical composition indicated that the most abundant particles...

  12. Statistical properties of pairwise distances between leaves on a random Yule tree.

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    Michael Sheinman

    Full Text Available A Yule tree is the result of a branching process with constant birth and death rates. Such a process serves as an instructive null model of many empirical systems, for instance, the evolution of species leading to a phylogenetic tree. However, often in phylogeny the only available information is the pairwise distances between a small fraction of extant species representing the leaves of the tree. In this article we study statistical properties of the pairwise distances in a Yule tree. Using a method based on a recursion, we derive an exact, analytic and compact formula for the expected number of pairs separated by a certain time distance. This number turns out to follow a increasing exponential function. This property of a Yule tree can serve as a simple test for empirical data to be well described by a Yule process. We further use this recursive method to calculate the expected number of the n-most closely related pairs of leaves and the number of cherries separated by a certain time distance. To make our results more useful for realistic scenarios, we explicitly take into account that the leaves of a tree may be incompletely sampled and derive a criterion for poorly sampled phylogenies. We show that our result can account for empirical data, using two families of birds species.

  13. Statistical properties of pairwise distances between leaves on a random Yule tree.

    Science.gov (United States)

    Sheinman, Michael; Massip, Florian; Arndt, Peter F

    2015-01-01

    A Yule tree is the result of a branching process with constant birth and death rates. Such a process serves as an instructive null model of many empirical systems, for instance, the evolution of species leading to a phylogenetic tree. However, often in phylogeny the only available information is the pairwise distances between a small fraction of extant species representing the leaves of the tree. In this article we study statistical properties of the pairwise distances in a Yule tree. Using a method based on a recursion, we derive an exact, analytic and compact formula for the expected number of pairs separated by a certain time distance. This number turns out to follow a increasing exponential function. This property of a Yule tree can serve as a simple test for empirical data to be well described by a Yule process. We further use this recursive method to calculate the expected number of the n-most closely related pairs of leaves and the number of cherries separated by a certain time distance. To make our results more useful for realistic scenarios, we explicitly take into account that the leaves of a tree may be incompletely sampled and derive a criterion for poorly sampled phylogenies. We show that our result can account for empirical data, using two families of birds species.

  14. [Tree uprooting of coniferous-broad leaved Korean pine mixed forest in Lesser Khingan Mountains, China].

    Science.gov (United States)

    Ge, Xiao-wen; Hou, Jie-jian; Wang, Li-hai; Wang, Xing-long; Rong, Bin-bin

    2016-02-01

    The morphological parameters, root wad indexes and site conditions of 127 uprooting trees from 76 plots (20 mx20 m) in Lesser Khingan coniferous-broad leaved Korean pine mixed forest were measured. Then the influencing factors of uprooting differences and the relationship between uprooting trees and disturbed soil were analyzed. Results showed that the number of uprooting trees varied significantly among species. Abies nephrolepis suffered the most serious uprooting damage, then Pinus koraiensis, and Ulmus spp. the least. Deciduous species had a stronger uprooting-resistant capacity than broad-leaved species. With the increase of tree DBH and height, tree' s uprooting resistance declined rapidly first and then was gradually enhanced, and finally reached the minimum at diameter class of 20 cm and height class of 14 m, respectively. The smaller the taper degree and projected area of crown were, the stronger the uprooting resistance was. Uprooting rate was negatively correlated with stand density. Trees lying in wet ground, flat terrain, medium low altitude area and windward slope had a greater risk of uprooting. There were significant positive correlation between the depth, area and volume of disturbed soil and the DBH, height, volume of uprooting trees.

  15. [Tree uprooting of coniferous-broad leaved Korean pine mixed forest in Lesser Khingan Mountains, China].

    Science.gov (United States)

    Ge, Xiao-wen; Hou, Jie-jian; Wang, Li-hai; Wang, Xing-long; Rong, Bin-bin

    2016-02-01

    The morphological parameters, root wad indexes and site conditions of 127 uprooting trees from 76 plots (20 mx20 m) in Lesser Khingan coniferous-broad leaved Korean pine mixed forest were measured. Then the influencing factors of uprooting differences and the relationship between uprooting trees and disturbed soil were analyzed. Results showed that the number of uprooting trees varied significantly among species. Abies nephrolepis suffered the most serious uprooting damage, then Pinus koraiensis, and Ulmus spp. the least. Deciduous species had a stronger uprooting-resistant capacity than broad-leaved species. With the increase of tree DBH and height, tree' s uprooting resistance declined rapidly first and then was gradually enhanced, and finally reached the minimum at diameter class of 20 cm and height class of 14 m, respectively. The smaller the taper degree and projected area of crown were, the stronger the uprooting resistance was. Uprooting rate was negatively correlated with stand density. Trees lying in wet ground, flat terrain, medium low altitude area and windward slope had a greater risk of uprooting. There were significant positive correlation between the depth, area and volume of disturbed soil and the DBH, height, volume of uprooting trees. PMID:27396108

  16. Development of Epiphyas postvittana (Lepidoptera: Tortricidae) on leaves and fruit of orange trees.

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    Mo, Jianhua; Glover, Michelle; Munro, Scott; Beattie, G Andrew C

    2006-08-01

    Development of Epipyas postvittna (Walker) (Lepidoptera: Tortricidae), on leaves and fruit of 'Valencia', 'Washington navel', and 'Navelina' orange trees was studied under constant and fluctuating temperatures. E. postvittna was able to complete its life cycle feeding exclusively on leaves or fruit of orange trees. However, larval survival rate was very low (types of orange tissues, young orange leaves and fruit afforded larvae higher survival rates than mature orange leaves and fruit. Fruit (young or mature) produced heavier pupae than leaves (young or mature). Larvae developed more slowly on mature orange fruit than on other orange materials and more slowly on orange leaves than on leaves of most noncitrus hosts. Degree-day accumulations based on the fastest developmental rates obtained in this study suggested that E. postvittna is capable of completing 4.4-4.7 generations per year in orange orchards in the Riverina region of New South Wales, Australia. Implications of the results in the management of the insect in citrus are discussed.

  17. Contribution to biomonitoring of some trace metals by deciduous tree leaves in urban areas.

    Science.gov (United States)

    Tomasević, M; Vukmirović, Z; Rajsić, S; Tasić, M; Stevanović, B

    2008-02-01

    Leaves of the deciduous tree species, horse chestnut (Aesculus hippocastanum L.) and Turkish hazel (Corylus colurna L.) were used as accumulative biomonitors of trace metal pollution in the urban area of Belgrade. Using differential pulse anodic stripping voltametry, trace metal concentrations (Pb, Cu, Zn, Cd) were determined at the single leaf level (ten leaves per species, per month), during two successive years with markedly different atmospheric level of trace metals. Increased trace metal concentrations in the leaves of A. hippocastanum reflected elevated atmospheric trace metal pollution, whereas C. colurna L. did not respond accordingly. The contents of Pb and Zn in soil over the same period also followed this trend. Anatomical analyses, in young as well as in old leaves of both species, indicated typical foliar injuries of plants exposed to stressful air conditions. Water relations that correspond to leaf age may have contributed to the considerable trace metal accumulation in leaves. PMID:17505898

  18. [Effects of temperature on CH4 emission from subtropical common tree species leaves].

    Science.gov (United States)

    Yang, Yan-Hua; Yi, Li-Ming; Xie, Jin-Sheng; Yang, Zhi-Jie; Jiang, Jun; Xu, Chao; Yang, Yu-Sheng

    2013-06-01

    Laboratory incubation test was conducted to study the effects of temperature on the CH4 emission from the leaves of subtropical common tree species Castanopsis carlesii, Schima superb, Cinnamomum chekiangense, Castsanopsis fabri, Cunninghamia lanceolata, and Citrus reticulata. Among the six tree species, only S. superb, C. reticulate, and C. fabri emitted CH4 at 10 degrees C. At above 20 degrees C, all the six species emitted CH4, and the average CH4 emission rate at above 30 degrees C (1.010 ng CH4 x g(-1) DM x h(-1)) was 2.96 times higher than that at 10-30 degrees C (0.255 ng CH4 x g(-1) DM x h(-1)). Moreover, increasing temperature had much more effects on the CH4 emission rate of C. reticulata and C. lanceolata than on that of the other four tree species. Incubation time affected the CH4 emission rate of all test tree species significantly, suggesting that the effects of temperature stress on the CH4 emission could be controlled by plant activity. Dry leaves could not emit CH4 no matter the temperature was very high or low. It was suggested that high temperature stress had important effects on the CH4 emission from subtropical tree leaves, and global warming could increase the CH4 emission from plants. PMID:24066538

  19. Determination of feed value of cherry, apricot and almond tree leaves in ruminant using in situ method

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    S. Mahmoudi

    2012-09-01

    Full Text Available In the present study, chemical composition and in situ rumen dry matter degradability (DMD of some tree species (cherry, apricot and almond tree leaves were determined. Crude protein (CP concentration varied from 6.76% for almond tree to 2.76% for cherry tree, neutral detergent fiber (NDF and acid detergent fiber (ADF, from 29.2, 20.8% for apricot tree to 20.8 and 15.8% for almond tree leaves respectively. Polyphenol and tannin composition measured from 3.49, 1.2% for almond tree to 1.51 and 0.61% for apricot tree, respectively. In situ rumen degradability was carried out in three fistulaed Taleshi native male cattle which were incubated at times of 0, 4, 8, 16, 24, 48, 72 and 96-hour. Almond leaves had higher potential degradation (a+b for dry matter (92.37% and cherry leaves showed lower potential degradation (84.12%, respectively. Effective rumen degradable dry matter at rate of 0.05/h varied from 69.86% for almond tree to 52.20% for cherry leaves. Results showed that the almond leaves were higher in nutritive value than cherry and apricot leaves. Therefore, almond tree leaves could be used with forage in ruminant diets to reduce cost of animals feed requirements. Overall, it seemed that the tree leaves used in this study, had a higher nutritive value in ruminant’s nutrition, however more experiments are needed for an accurate determination of nutritional values of these resources.

  20. Spectral variability of deciduous leaves depending on the developmental stages and tree condition

    Science.gov (United States)

    Song, Y.; Ryu, Y.

    2013-12-01

    Foliar spectral characteristics could be the key information in modeling forest ecosystem and the remote sensing of vegetation identification. But it is not easy to determine a typical leaf spectrum of a species in a standardized state. That is because of variables critically influencing on the spectral property of leaves, such as inter- and intra-species features, phenological phase, or biotic and abiotic stress. In this study, we attempted to quantify the spectral variability of leaves depending on species, developmental stages, and the condition of trees. The contribution of these factors to the spectral variation was analyzed at the single leaf level, with a large number of samples from deciduous plants in the urban forested area. First, we collected tens of leaf-samples at every biweekly fieldwork in the growing season, for the selected 5 tree species popular in urban parks; Acer palmatum, Carpinus laxiflora, Prunus yedoensis, Quercus acutissima, and Zelkova serrata. And absorbance, reflectance and transmittance spectra of the leaves were acquired at the short-visible (400-700 nm) to infrared (700-2500 nm) spectral region with 1 nm interval. Seasonality in these leaf-spectra was used to understand the inter-species variation depending on developmental stages. Second, as a benchmark for testing intra-species variability and differences by tree condition, we additionally analyzed the spectral reflectance of 504 ripe leaves from 56 cherry trees (Cerasus × yedoensis) collected in the middle of summer. Last, using ANOVA (analysis of variance) and general linear model, we assessed the influence of our tested variables (i.e., species, developmental stage, and tree condition) on the spectral characteristics and their vegetation indices. As a result, we clarified that the changes in leaf-spectra was apparent across all the tested species during the growing season from May to June, indicating the increasing trend of absorbance in photosynthetically active radiation

  1. Optical solar energy adaptations and radiative temperature control of green leaves and tree barks

    Energy Technology Data Exchange (ETDEWEB)

    Henrion, Wolfgang; Tributsch, Helmut [Department of Si-Photovoltaik and Solare Energetik, Hahn-Meitner-Institut Berlin, 14109 Berlin (Germany)

    2009-01-15

    Trees have adapted to keep leaves and barks cool in sunshine and can serve as interesting bionic model systems for radiative cooling. Silicon solar cells, on the other hand, loose up to one third of their energy efficiency due to heating in intensive sunshine. It is shown that green leaves minimize absorption of useful radiation and allow efficient infrared thermal emission. Since elevated temperatures are detrimental for tensile water flow in the Xylem tissue below barks, the optical properties of barks should also have evolved so as to avoid excessive heating. This was tested by performing optical studies with tree bark samples from representative trees. It was found that tree barks have optimized their reflection of incoming sunlight between 0.7 and 2 {mu}m. This is approximately the optical window in which solar light is transmitted and reflected by green vegetation. Simultaneously, the tree bark is highly absorbing and thus radiation emitting between 6 and 10 {mu}m. These two properties, mainly provided by tannins, create optimal conditions for radiative temperature control. In addition, tannins seem to have adopted a function as mediators for excitation energy towards photo-antioxidative activity for control of radiation damage. The results obtained are used to discuss challenges for future solar cell optimization. (author)

  2. PIXE analysis of tree leaves as a possible comparative integral monitor of particulates in urban areas

    International Nuclear Information System (INIS)

    The possibility of obtaing integral comparative data for particulate distribution in urban areas from PIXE analysis of tree leaves is discussed in relation to the leaf gross anatomy, to the diffusion of selected tree species in such areas and to the implementation of experimental techniques necessary to make PIXE analysis effective. Multielemental scans were performed on a small set samples; results are compared to PIXE analysis of typical urban aerosols. The validity of the method and the criteria for yearly relative comparisons of different areas are discissed

  3. Nutritional value of tree leaves for livestock from a semi-hilly arid region of India

    International Nuclear Information System (INIS)

    Samples of 13 species of forest tree leaves growing in the semi-hilly arid zone of Punjab State in India were collected at 30 day intervals over 12 months, in order to assess their nutritional value for livestock. The ground samples were pooled for four seasons: dry hot, hot humid, fall, and winter. The data were arranged in a 13 x 4 factorial design for analysis. For tannin fractionation, leaves of 12 species containing more than 3.5% total phenols were selected and data were analysed within a 12 x 12 factorial design. The chemical composition, irrespective of the season, revealed that Leucaena had the highest crude protein (CP, 220 g/kg dry matter). Globulin was the major protein fraction in most of the leaves. The lowest concentration of neutral detergent fibre (NDF) was in Morus, Acacia and Grewea spp. Fibre and lignin content increased during the fall and winter. The leaves of Grewea, Morus, Leucaena, Carrisa and Acacia were rich in Ca, P and most of the trace elements. The total phenolics ranged between 38 (Toona) and 169 g/kg DM (Anogeisus). The leaves of Anogeisus had the highest concentration of hydrolysable tannins (16.9%) whereas those of Carrisa had highest condensed tannins (4.6%). The condensed tannins (>3%) were negatively correlated to the digestibility of dry matter (DM), NDF and CP. The digestion kinetic parameters for DM, NDF and CP revealed that leaves of Morus alba, Zizyphus and Ehretia were most degradable. The minimum rumen fill values also revealed that leaves of Grewea, Azadirachta, Morus, Ehretia and Leucaena had higher potential for voluntary DM intake, especially compared to leaves of Ougeinia, Zizyphus xylopyrus, Dodonea and Carrisa. During winter, most of the leaves had a low potentially degradable fraction, with a low rate of degradation. Screening leaves by the in vitro gas production technique suggested that leaves of Melia azedarach, Azadirachta indica, Morus alba and Leucaena leucocephala were potential feeds for ruminants

  4. [C, N, P stoichiometric characteristics of tree, shrub, herb leaves and litter in forest community of Shaanxi Province, China].

    Science.gov (United States)

    Jiang, Pei-pei; Cao, Yang; Chen, Yun-ming

    2016-02-01

    A total of 121 sampling sites were selected to study the C, N, P stoichiometric characteristics among the leaves of tree, shrub, herb and the litter of the majority forest community of Shaanxi Province, China. We also studied their relationships with geographical factors. The results showed that C, N concentrations were highest in tree leaf, P concentration was highest in herb leaf, and the C, N, P concentrations were lowest in litter. Leaf C: N: P ratios of tree, shrub, herb leaves and litter were 439.4:14.2:1, 599.2:13.5:1, 416.5:13.3:1, 504.8:15.5:1, respectively. The N:P ratios of tree, shrub and herb leaves were not significantly different, but they were all significantly higher than that of litter layer, indicating N:P ratio of different living life forms' leaves was stable. Compared with N, C and P had better relationships in each layer, and the relationships of leaf C, N, P stoichiometry between tree and herb leaves were better than those between tree and shrub leaves. The correlations of C, N, P stoichiometry between litter and the tree or herb leaves were highly significantly positive, and the correlations of P stoichiometry between litter and shrub leaves were highly significantly positive. Shrub leaf N, P concentration increased with the increasing latitude, and herb leaf N, P concentrations decreased with the increasing longitude. Compared with the longitude and latitude, the effect of altitude was smaller, and only tree leaf N:P decreased with the increasing latitude. Multivariate linear regression analysis results showed that the influence of geographical factors on herb leaf was longitude > latitude > altitude, while was latitude > longitude > altitude for tree, shrub leaves and litter. PMID:27396106

  5. Trace element content in urban tree leaves and SEM-EDAX characterization of deposited particles

    Directory of Open Access Journals (Sweden)

    Tomašević Milica

    2010-01-01

    Full Text Available Leaves of common deciduous trees: Aesculus hippocastanum and Tilia spp. from three parks within the urban area of Belgrade (Serbia were studied as biomonitors of trace elements (V, Cr, Fe, Ni, Cu, Zn, As, Cd, and Pb air pollution. Using a scanning SEM-EDAX, the size, size distribution, morphology and chemical composition of individual particles were examined on adaxial and abaxial surfaces of the leaves. Morphological and chemical composition indicated that the most abundant particles were soot and dust with minor constituents such as Pb, Zn, Ni, V, Cd, Ti, As, and Cu. Total element concentrations in the leaves were determined by ICP-OES and ICP-MS. This investigation included spatial, seasonal, and temporal variations in leaves of the selected species. The leaves of A. hippocastanum showed a significantly higher elements concentration and more consistency in trend of element accumulation during the vegetation season in the period 2002-2006 than Tilia spp., so it may be considered as a more suitable species for the assessment of trace element atmospheric pollution, especially Pb and Cu which correlated with the bulk deposition data.

  6. ENVIRONMENTAL MONITORING USING LINDEN TREE LEAVES AS NATURAL TRAPS OF ATMOSPHERIC DEPOSITION: A PILOT STUDY IN TRANSILVANIA, ROMANIA

    OpenAIRE

    MIHÁLY BRAUN; ZITA MARGITAI; ALBERT TÓTH; MARTINE LEERMAKERS

    2007-01-01

    Atmospheric pollution caused by toxic elements is an emerging problem of concern. Tree leaves have been widely used as indicator of atmospheric pollutions and they are effective alternatives to the moreusual biomonitoring methods. Tree leaves can be used as natural traps of atmospheric deposition. Elemental composition of dust deposited onto leaf surfaces can be used to characterize the urban environment. A pilot survey including 16 Romanian settlements was carried out in order to evaluate th...

  7. Framework for using deciduous tree leaves as biomonitors for intraurban particulate air pollution in exposure assessment.

    Science.gov (United States)

    Gillooly, Sara E; Shmool, Jessie L Carr; Michanowicz, Drew R; Bain, Daniel J; Cambal, Leah K; Shields, Kyra Naumoff; Clougherty, Jane E

    2016-08-01

    Fine particulate matter (PM2.5) air pollution, varying in concentration and composition, has been shown to cause or exacerbate adverse effects on both human and ecological health. The concept of biomonitoring using deciduous tree leaves as a proxy for intraurban PM air pollution in different areas has previously been explored using a variety of study designs (e.g., systematic coverage of an area, source-specific focus), deciduous tree species, sampling strategies (e.g., single day, multi-season), and analytical methods (e.g., chemical, magnetic) across multiple geographies and climates. Biomonitoring is a low-cost sampling method and may potentially fill an important gap in current air monitoring methods by providing low-cost, longer-term urban air pollution measures. As such, better understanding of the range of methods, and their corresponding strengths and limitations, is critical for employing the use of tree leaves as biomonitors for pollution to improve spatially resolved exposure assessments for epidemiological studies and urban planning strategies. PMID:27450373

  8. Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2016-01-01

    Full Text Available Subtropical evergreen broad-leaved forest (EBLF is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ≥50% for 19 species. The median length of germination time (MLG ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (≥15 cm in height within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration.

  9. On the Distribution of Leaves in Rooted Subtrees of Recursive Trees

    OpenAIRE

    Mahmoud, Hosam M.; Smythe, R. T.

    1991-01-01

    We study the structure of $T^{(k)}_n$, the subtree rooted at $k$ in a random recursive tree of order $n$, under the assumption that $k$ is fixed and $n \\rightarrow \\infty$. Employing generalized Polya urn models, exact and limiting distributions are derived for the size, the number of leaves and the number of internal nodes of $T^{(k)}_n$. The exact distributions are given by intricate formulas involving Eulerian numbers, but a recursive argument based on the urn model suffices for establishi...

  10. Antioxidant Properties and Total Phenolic Content of Three Varieties of Carob Tree Leaves from Morocco

    Directory of Open Access Journals (Sweden)

    Brahim El Bali

    2010-10-01

    Full Text Available The in vitro antioxidant activity and the total phenolic content (Folin−Ciocalteu method of three successive extracts of three varieties of Ceratonia siliqua L. leaves ( grafted female, spontaneous female, spontaneous male grown in Morocco were investigated by using in-vitro antioxidant models including 1,1-diphenyl-2-picrylhydrazyl (DPPH scavenging assay, reducing power and total antioxidant capacity . T he global polyphenols concentration ranged from 0.45 to 2.64 (g/L GAE in the three categories of the extracts . In each variety, ethyl acetate fraction exhibited the highest antioxidant activity compared to other fractions. Grafted female trees globally showed a higher polyphenols concentration than the spontaneous female and spontaneous male ones. Our results clearly demonstrate that all extracts have antioxidant capacity. Among the categores, the ethyl acetate extracts of carob tree leaves exhibited strong scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH than the diethyl ether and dichloromethane extracts. Carob leaf extracts contain high amounts of polyphenols with strong antiradical, antioxidant capacity and reducing properties which might constitute an important source of natural antioxidants.

  11. Chemometrics in biomonitoring: Distribution and correlation of trace elements in tree leaves.

    Science.gov (United States)

    Deljanin, Isidora; Antanasijević, Davor; Bjelajac, Anđelika; Urošević, Mira Aničić; Nikolić, Miroslav; Perić-Grujić, Aleksandra; Ristić, Mirjana

    2016-03-01

    The concentrations of 15 elements were measured in the leaf samples of Aesculus hippocastanum, Tilia spp., Betula pendula and Acer platanoides collected in May and September of 2014 from four different locations in Belgrade, Serbia. The objective was to assess the chemical characterization of leaf surface and in-wax fractions, as well as the leaf tissue element content, by analyzing untreated, washed with water and washed with chloroform leaf samples, respectively. The combined approach of self-organizing networks (SON) and Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) aided by Geometrical Analysis for Interactive Aid (GAIA) was used in the interpretation of multiple element loads on/in the tree leaves. The morphological characteristics of the leaf surfaces and the elemental composition of particulate matter (PM) deposited on tree leaves were studied by using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) detector. The results showed that the amounts of retained and accumulated element concentrations depend on several parameters, such as chemical properties of the element and morphological properties of the leaves. Among the studied species, Tilia spp. was found to be the most effective in the accumulation of elements in leaf tissue (70% of the total element concentration), while A. hippocastanum had the lowest accumulation (54%). After water and chloroform washing, the highest percentages of removal were observed for Al, V, Cr, Cu, Zn, As, Cd and Sb (>40%). The PROMETHEE/SON ranking/classifying results were in accordance with the results obtained from the GAIA clustering techniques. The combination of the techniques enabled extraction of additional information from datasets. Therefore, the use of both the ranking and clustering methods could be a useful tool to be applied in biomonitoring studies of trace elements. PMID:26748000

  12. Investigating and modeling the pyrolysis kinetic of leaves and stems of pistachio trees for biofuel production

    Directory of Open Access Journals (Sweden)

    M Ostad Hoseini

    2016-09-01

    Full Text Available Introduction The lignocelluloses materials have high potential for producing various types of biofuels. These materials include various parts of plants, especially leaves and stems that are left without a specific usage after annual pruning. These residues can be used through slow or fast pyrolysis process for production of liquid and gaseous biofuels. The slow pyrolysis is taking place at temperatures below 500°C while fast pyrolysis process takes place at a temperature above 700°C. Various studies on production of biofuels from plant residues have shown that the temperature, heating rate and the resident time of pyrolysis process are the main factors that affect the final product quality. At present time, in Iran, there are more than 360 thousands hectares of pistachio growing fields which annually produce over 215 thousands metric tons residues which are mainly leaves and stems. The main objective of this study was to measure the heating properties of the powders prepared from the leaves and the stem of pistachio trees. These properties include higher heating value (HHV, lower heating value (LHV and thermal gravimetric analysis (TGA of the powders. Then the powders were separately pyrolysed and the kinetic of the pyrolysis process for producing charcoal from them was investigated. Materials and Methods In this research, leaves and stems of pistachio trees were initially analyzed to determine their chemical constituents including moisture content, volatile compounds, carbon (C, hydrogen (H, nitrogen (N, sulfur (S and oxygen (O content. Using these constituents the height heating value and low heating value for the leaves and the stems were determined. The thermal gravimetric analysis (TGA of the powders was made to select a proper heating temperature for pyrolysis of the powders. In each experiment about 10 g of powder powders were pyrolyzed to produce char. Based on TGA results, the pyrolysis experiments were performed at 350, 400, 450 and

  13. ENVIRONMENTAL MONITORING USING LINDEN TREE LEAVES AS NATURAL TRAPS OF ATMOSPHERIC DEPOSITION: A PILOT STUDY IN TRANSILVANIA, ROMANIA

    Directory of Open Access Journals (Sweden)

    MIHÁLY BRAUN

    2007-12-01

    Full Text Available Atmospheric pollution caused by toxic elements is an emerging problem of concern. Tree leaves have been widely used as indicator of atmospheric pollutions and they are effective alternatives to the moreusual biomonitoring methods. Tree leaves can be used as natural traps of atmospheric deposition. Elemental composition of dust deposited onto leaf surfaces can be used to characterize the urban environment. A pilot survey including 16 Romanian settlements was carried out in order to evaluate the characteristics and sources of air pollutants. Tree leaves (Tilia tomentosa, Tilia cordata, Tilia platyphyllos were collected and used for the measurements. Elemental analyses were carried out by ICP-OES and ICP-MS. Principal component and discriminant analyses were used to characterizing and estimating the level of pollution. Settlements were grouped on the basis of discriminant function values. Multivariate comparison of chemical data ordered the settlements into 3 main groups, which showed a systematic geographic distribution.

  14. Chlorophyll fluorescence kinetics, photosynthetic activity, and pigment composition of blue-shade and half-shade leaves as compared to sun and shade leaves of different trees.

    Science.gov (United States)

    Lichtenthaler, Hartmut K; Babani, Fatbardha; Navrátil, Martin; Buschmann, Claus

    2013-11-01

    The chlorophyll (Chl) fluorescence induction kinetics, net photosynthetic CO2 fixation rates P N, and composition of photosynthetic pigments of differently light exposed leaves of several trees were comparatively measured to determine the differences in photosynthetic activity and pigment adaptation of leaves. The functional measurements were carried out with sun, half-shade and shade leaves of seven different trees species. These were: Acer platanoides L., Ginkgo biloba L., Fagus sylvatica L., Platanus x acerifolia Willd., Populus nigra L., Quercus robur L., Tilia cordata Mill. In three cases (beech, ginkgo, and oak), we compared the Chl fluorescence kinetics and photosynthetic rates of blue-shade leaves of the north tree crown receiving only blue sky light but no direct sunlight with that of sun leaves. In these cases, we also determined in detail the pigment composition of all four leaf types. In addition, we determined the quantum irradiance and spectral irradiance of direct sunlight, blue skylight as well as the irradiance in half shade and full shade. The results indicate that sun leaves possess significantly higher mean values for the net CO2 fixation rates P N (7.8-10.7 μmol CO2 m(-2) s(-1) leaf area) and the Chl fluorescence ratio R Fd (3.85-4.46) as compared to shade leaves (mean P N of 2.6-3.8 μmol CO2 m(-2) s(-1) leaf area.; mean R Fd of 1.94-2.56). Sun leaves also exhibit higher mean values for the pigment ratio Chl a/b (3.14-3.31) and considerably lower values for the weight ratio total chlorophylls to total carotenoids, (a + b)/(x + c), (4.07-4.25) as compared to shade leaves (Chl a/b 2.62-2.72) and (a + b)/(x + c) of 5.18-5.54. Blue-shade and half-shade leaves have an intermediate position between sun and shade leaves in all investigated parameters including the ratio F v/F o (maximum quantum yield of PS2 photochemistry) and are significantly different from sun and shade leaves but could not be differentiated from each other. The

  15. Magnetic properties of highroad-side pine tree leaves in Beijing and their environmental significance

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chunxia; HUANG Baochun; LI Zhenyu; LIU He

    2006-01-01

    This is a report on magnetic properties of highroad-side tree (Pinus pumila Regel) leaves collected along an expressway linking Beijing City and the Capital International Airport and further focus on their environmental contributions. A series of rock magnetic experiments show that the primary magnetic mineral of leaf samples was identified to be magnetite, in the pseudo-single domain (PSD) grain size range 0.2-5.0μm. On the other hand, magnetite concentration and grain size in leaves are ascertained to decrease with increasing of sampling distance to highroad asphalt surface, suggesting that high magnetic response to traffic pollution is localized within a distance of some two meters away from highroad asphalt surface. Although magnetic susceptibility is ordinarily regarded as a simple, rapid and low-cost method for monitoring traffic pollution,saturation isothermal remanent magnetization (SIRM)can be treated as a valid proxy for monitoring air particulate matter (PM) when samples are magnetically weak. It is believed that a synthetic rock magnetic study is an effective method for determining concentration and grain size of ferromagnets in the atmospheric PM, and then it should be a rapid and feasible technique for monitoring atmospheric pollution.

  16. Nitrogen content and nitrogen reserves in annual leaves and offshoots of apple trees undergoing foliar nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Gustavo Brunetto

    2012-11-01

    Full Text Available Foliar applications of nitrogen (N, when needed, have been used to supplement the fertilization of fruit trees through the soil. However, information on frequency effects, N amount to be applied, and the importance of increasing N content and N reserves in the leaves and offshoots are few. This paper aimed at evaluating the effect of foliar N applications on the N content and reserves in annual leaves and offshoots of apple trees. The study was carried out in an apple trees orchard (Eva cultivar, crop 2007/2008, in the experimental area of the Polytechnic College of Universidade Federal de Santa Maria (UFSM, in the town of Santa Maria, Rio Grande do Sul, Brazil, on a hydromorphic planosol. The treatments consisted of 1 and 2 foliar applications of 0; 1.11; 2.23; 3.31; 4.41; and 5.51g of N plant-1. The results showed that foliar N applications resulted in increased N contents in the whole leaves, especially up to the 8th day after application, but they do not affect N content in the annual offshoots. Nitrogen fertilization via the leaves did not increase the total content of amino acids and proteins in the annual whole leaves and offshoots

  17. Accumulation of sulfur and heavy metals in soil and tree leaves sampled from the surroundings of Tuncbilek Thermal Power Plant.

    Science.gov (United States)

    Cicek, A; Koparal, A S

    2004-11-01

    In this study, the quantities of sulfur and heavy metals, resulting from the Tuncbilek Thermal Power Plant (TPP) in Turkey, have been assessed in tree leaves and soil samples within a 10 km radius of the plant. Leaves of Salix alba L., Populus tremula L., Robinia pseudoacacia L., Quercus infectoria L., Pinus nigra Arn. ssp. pallasiana (Lamb) Holmboe. trees have been used with the aim of determining how far the gas and particles emitted from the TPP are carried, and for assessment of environmental impact. The results obtained from locations chosen at various distances to the TPP, indicate that the contaminating agents are very dense and effective; particularly in the prevailing wind direction and within 10 km of the plant. They gradually lose their density and effect beyond this distance. The sulfur and heavy metal analyses made in soils taken from these locations indicate a similarity with the data obtained from the leaves. PMID:15488593

  18. Accumulation of sulfur and heavy metals in soil and tree leaves sampled from the surroundings of Tuncbilek Thermal Power Plant.

    Science.gov (United States)

    Cicek, A; Koparal, A S

    2004-11-01

    In this study, the quantities of sulfur and heavy metals, resulting from the Tuncbilek Thermal Power Plant (TPP) in Turkey, have been assessed in tree leaves and soil samples within a 10 km radius of the plant. Leaves of Salix alba L., Populus tremula L., Robinia pseudoacacia L., Quercus infectoria L., Pinus nigra Arn. ssp. pallasiana (Lamb) Holmboe. trees have been used with the aim of determining how far the gas and particles emitted from the TPP are carried, and for assessment of environmental impact. The results obtained from locations chosen at various distances to the TPP, indicate that the contaminating agents are very dense and effective; particularly in the prevailing wind direction and within 10 km of the plant. They gradually lose their density and effect beyond this distance. The sulfur and heavy metal analyses made in soils taken from these locations indicate a similarity with the data obtained from the leaves.

  19. Measurement of tritiated water transpiration from tree leaves following root injection

    International Nuclear Information System (INIS)

    The Sydney Water Board were looking for a means of assessing the efficacy and practicality of using tritiated water (HTO) for the treatment of sewer systems infested by tree roots. After discussion, it was agreed that ANSTO would assess the use of tritiated water as a means of determining the water transport function in roots. The proposed method of assessment is based upon measuring the rate at which tritiated water is moved away from the root infesting the sewer by the normal transpiration stream. The method assumes that the treatment applied to the sewer drastically reduces, if not destroys, root function. This should be reflected in a significant increase in the delay of HTO arrival at the leaves following application to the affected root. Any significant flux from the affected root would indicate inadequate treatment as water flow from the affected root would encourage subsequent re-invasion of the sewer. If deemed suitable, this tracer would in turn be used to determine the efficacy of the treatment in inhibiting root function. Constraints on the study as well as the optimal conditions for using HTO are discussed. The method which involves injection of tritium into the xylem tissue of the tree followed by collection of transpirate to observe the pattern of tritium arrival, is amenable to the task of assessing the efficiency of the treatment process if the site of infestation can be excavate without damage to the roots and if HDO can be injected and sealed with a root of adequate dimensions. 2 refs., 1 tab., 7 figs

  20. Assessment of fodder quality of leaves of multipurpose trees in subtropical humid climate of India

    Institute of Scientific and Technical Information of China (English)

    Chander Datt; M. Datta; N. P. Singh

    2008-01-01

    The leaves of 12 species (Acacia auriculiformis, Albizzia procera, Dalbergia sissoo, Gliricidia maculata, Leucaena leucocephala, Samanea saman, Azadirachta indica, Eucalyptus hybrida, Gmelina arborea, Michelia champaca, Morus alba, and Tectona grandis) of Multipurpose trees and shrubs (MPTs) grown in the agroforestry arboretum were evaluated for their nutritional characteristics in terms of proximate composition, cell wall constituents, total tannins, major (Ca and P) and trace minerals (Fe, Cu, Zn, Mn and Co), in vitro dry matter and organic matter digestibility (IVDMD and IVOMD) and metabolisable energy (ME) values. There were significant (P<0.01) variations among MPTs for all parameters studied. The average values of (92.02±0.30)%, (16.00±0.74)%, (3.05±0.13)%, (18.97±1.07)%, (54.00±1.12)% and (7.98 ± 0.30)% (DM basis) were observed for OM (organic matter), CP (crude protein), EE (ether extract), CF (crude fibre), NFE (nitrogen-free extract) and total ash, respectively. Leguminous trees had high CP compared to non-leguminous ones (18.30% vs 13.70%). The mean values for cell wall constituents viz., NDF (neutral detergent fibre), ADF (acid detergent fibre), hemi cellulose, cellulose and ADL (acid detergent lignin) were found to be (52.48±1.05)%, (31.72±0.97)%, (20.76±0.88)%, (16.97±0.70)% and (9.57±0.62)%, respectively. The total tannin contents averaged (4.22±0.32)%. The ratio of Ca to P was quite wider. The levels of Fe and Mn were adequate to rich in all the MPTs while many of the tree species possessed P, Cu, Zn and Co level below the critical limits for the animals. The average IVDMD and IVOMD values were found to be (48.96±1.30)% and (50.69±1.36)%, respectively. The ME value averaged (6.95±0.11) MJ·kg-1 DM. The CP content had significant positive correlation with IVDMD, IVOMD and ME values while NDF, ADF, ADL and total tannins showed negative correlations with these three parameters. Based on the results, Leucaena Leucocephala could be

  1. Chlorophyll Catabolites in Fall Leaves of the Wych Elm Tree Present a Novel Glycosylation Motif.

    Science.gov (United States)

    Scherl, Mathias; Müller, Thomas; Kreutz, Christoph R; Huber, Roland G; Zass, Engelbert; Liedl, Klaus R; Kräutler, Bernhard

    2016-07-01

    Fall leaves of the common wych elm tree (Ulmus glabra) were studied with respect to chlorophyll catabolites. Over a dozen colorless, non-fluorescent chlorophyll catabolites (NCCs) and several yellow chlorophyll catabolites (YCCs) were identified tentatively. Three NCC fractions were isolated and their structures were characterized by spectroscopic means. Two of these, Ug-NCC-27 and Ug-NCC-43, carried a glucopyranosyl appendage. Ug-NCC-53, the least polar of these NCCs, was identified as the formal product of an intramolecular esterification of the propionate and primary glucopyranosyl hydroxyl groups of Ug-NCC-43. Thus, the glucopyranose moiety and three of the pyrrole units of Ug-NCC-53 span a 20-membered ring, installing a bicyclo[17.3.1]glycoside moiety. This structural motif is unprecedented in heterocyclic natural products, according to a thorough literature search. The remarkable, three-dimensional bicyclo[17.3.1]glycoside architecture reduces the flexibility of the linear tetrapyrrole. This feature of Ug-NCC-53 is intriguing, considering the diverse biological effects of known bicyclo[n.3.1]glycosidic natural products. PMID:27128523

  2. Optimization of Pb(II) biosorption by Robinia tree leaves using statistical design of experiments.

    Science.gov (United States)

    Zolgharnein, Javad; Shahmoradi, Ali; Sangi, Mohammad Reza

    2008-07-30

    The present study introduces Robinia tree leaves as a novel and efficient biosorbent for removing Pb(II) from aqueous solutions. In order to reduce the large number of experiments and find the highest removal efficiency of Pb(II), a set of full 2(3) factorial design with two blocks were performed in duplicate (16 experiments). In all experiments, the contact time was fixed at 25 min. The main interaction effects of the three factors including sorbent mass, pH and initial concentration of metal-ion were considered. By using Student's t-test and analysis of variances (ANOVA), the main factors, which had the highest effect on the removal process, were identified. Twenty-six experiments were designed according to Doehlert response surface design to obtain a mathematical model describing functional relationship between response and main independent variables. The most suitable regression model, that fitted the experimental data extremely well, was chosen according to the lack-of-fit-test and adjusted R(2) value. Finally, after checking for possible outliers, the optimum conditions for maximum removal of Pb(II) from aqueous solution were obtained. The best conditions were calculated to be as: initial concentration of Pb(II)=40 mg L(-1), pH 4.6 and concentration of sorbet equal to 27.3 g L(-1).

  3. Fine Root Productivity and Turnover of Ectomycorrhizal and Arbuscular Mycorrhizal Tree Species in a Temperate Broad-Leaved Mixed Forest.

    Science.gov (United States)

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2016-01-01

    Advancing our understanding of tree fine root dynamics is of high importance for tree physiology and forest biogeochemistry. In temperate broad-leaved forests, ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) tree species often are coexisting. It is not known whether EM and AM trees differ systematically in fine root dynamics and belowground resource foraging strategies. We measured fine root productivity (FRP) and fine root turnover (and its inverse, root longevity) of three EM and three AM broad-leaved tree species in a natural cool-temperate mixed forest using ingrowth cores and combined the productivity data with data on root biomass per root orders. FRP and root turnover were related to root morphological traits and aboveground productivity. FRP differed up to twofold among the six coexisting species with larger species differences in lower horizons than in the topsoil. Root turnover varied up to fivefold among the species with lowest values in Acer pseudoplatanus and highest in its congener Acer platanoides. Variation in root turnover was larger within the two groups than between EM and AM species. We conclude that the main determinant of FRP and turnover in this mixed forest is species identity, while the influence of mycorrhiza type seems to be less important. PMID:27617016

  4. Effect of the extraction process on yield and composition of selected extracts from maidenhair tree green and yellow leaves

    OpenAIRE

    Joanna Kobus-Cisowska; Ewa Flaczyk; Aleksander Siger; Dominik Kmiecik

    2015-01-01

    The aim of the study was to evaluate the effect of extraction process on the extraction efficiency and composition of selected extracts from the maidenhair tree (Ginkgo biloba L.) green and yellow leaves. Taken three-step extraction, where water, solution of acetone and water and ethyl alcohol were used, effectiveness by evaluating the content of total polyphenols was estimated. In the next step yield of selected extraction processes was estimated, then UV spectra of the obtained extracts and...

  5. Optimization and characterization of Tl(I) adsorption onto modified ulmus carpinifolia tree leaves

    Energy Technology Data Exchange (ETDEWEB)

    Zolgharnein, Javad; Asanjarani, Neda [Faculty of Science, Department of Chemistry, Arak University, Arak (Iran, Islamic Republic of); Mousavi, S. Norollah [Faculty of Science, Department of Mathematics, Arak University, Arak (Iran, Islamic Republic of)

    2011-03-15

    Ulmus carpinifolia tree leaves were successfully used to remove Tl(I) from aqueous solution in a batch system. In order to improve the uptake capacity of sorbent, it was modified by various chemical agents such as NaOH, HNO{sub 3}, NH{sub 3}, NaCl, NaHCO{sub 3}, and CaCl{sub 2}. Among the modifiers, NaCl was the best. Equilibrium behavior of sorbent with Tl(I) was examined by the several isotherms. Considering modified U. carpinifolia equilibrium data fitted well to the Langmuir model with maximum capacity of 54.6 mg/g. The other isotherms such as: Freundlich and Dubinin-Redushkevich (D-R) models were also examined. The central composite design (CCD) was successfully employed for optimization of biosorption process. An empirical model was given through using response surface methodology. Also its validation was recognized by using relevant statistical tests such as ANOVA. The optimum conditions of biosorption: pH, m (amount of sorbent) and C (initial concentration) were found to be 7.9, 11.4 g/L, and 8.8 mg/L, respectively. On the other hand thermodynamic parameters: {Delta}G, {Delta}H, and {Delta}S were evaluated: the obtained results show that biosorption process was spontaneous and exothermic. Eventually, FT-IR analysis confirmed that the main functional groups of sorbent have been involved through the biosorption process. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Leaves of Field-Grown Mastic Trees Suffer Oxidative Stress at the Two Extremes of their Lifespan

    Institute of Scientific and Technical Information of China (English)

    Marta Juvany; Maren Müller; Sergi Munné-Bosch

    2012-01-01

    Leaf senescence is a complex phenomenon occurring in all plant species,but it is still poorly understood in plants grown in Mediterranean field conditions and well-adapted to harsh climatic conditions.To better understand the physiological processes underlying leaf senescence in mastic trees (Pistacia lentiscus L.),we evaluated leaf growth,water and N content,photosystem Ⅱ (PSⅡ) photochemistry,lipid peroxidation and levels of photosynthetic pigments,antioxidants,abscisic acid,and salicylic acid and jasmonic acid during the complete leaf lifespan,from early expansion to late senescence in relation to natural climatic conditions in the field.While mature leaves suffered from water and N deficit during late spring and summer,both young (emerging) and old (senescing) leaves were most sensitive to photooxidative stress,as indicated by reductions in the Fv/Fm ratio and enhanced lipid peroxidation during late autumn and winter.Reductions in the Fv/Fm ratio were associated with low α-tocopherol (vitamin E) levels,while very old,senescing leaves additionally showed severe anthocyanin losses.We have concluded that both young (emerging) and old (senescing) leaves suffer oxidative stress in mastic trees,which may be linked in part to suboptimal temperatures during late autumn and winter as well as to low vitamin E levels.

  7. Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae

    Science.gov (United States)

    We investigated the effects of nitrogen (N) availability and spraying trees with urea, copper chelate (CuEDTA), and phosphonate-containing fungicides on tree N status and susceptibility to infection by Phytophthora syringae. Increasing soil N availability increased susceptibility and increased N and...

  8. Effect of the extraction process on yield and composition of selected extracts from maidenhair tree green and yellow leaves

    Directory of Open Access Journals (Sweden)

    Joanna Kobus-Cisowska

    2015-03-01

    Full Text Available The aim of the study was to evaluate the effect of extraction process on the extraction efficiency and composition of selected extracts from the maidenhair tree (Ginkgo biloba L. green and yellow leaves. Taken three-step extraction, where water, solution of acetone and water and ethyl alcohol were used, effectiveness by evaluating the content of total polyphenols was estimated. In the next step yield of selected extraction processes was estimated, then UV spectra of the obtained extracts and their content of phenolic acids. The content of phenolic compounds in the following extracts showed high efficiency of the first extraction process. Analysis of UV spectra allowed to deduce the presence of phenolic compounds in all tested extracts. The absorption maxima were recorded at wavelengths between 290 nm and 350 nm. Analysed extracts showed high content of phenolic acids. The largest of the sum of phenolic acids was estimated in the acetone-water extract from green leaves and in water extract from yellow leaves. In green leaves extracts the predominant acid was protocatechuic, while in yellow leaves extracts the greatest amount of p-hydroxybenzoic acid was shown.

  9. Quantitative analysis of arbutin and hydroquinone in strawberry tree (Arbutus unedo L., Ericaceae) leaves by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Jurica, Karlo; Karačonji, Irena Brčić; Šegan, Sandra; Opsenica, Dušanka Milojković; Kremer, Dario

    2015-09-01

    The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine arbutin and hydroquinone content in strawberry tree (Arbutus unedo L., Ericaceae) leaves. The method showed good linearity (R2>0.9987) in the tested concentration range (0.5-200 μg mL(-1)), as well as good precision (RSDarbutin and hydroquinone, respectively). The results obtained by the validated GC-MS method corresponded well to those obtained by high performance liquid chromatography (HPLC) method. The proposed method was then applied for determining arbutin and hydroquinone content in methanolic leaf extracts. The amount of arbutin in the leaves collected on the island of Koločep (6.82 mg g(-1) dry weight) was found to be higher (tpaired=43.57, tc=2.92) in comparison to the amount of arbutin in the leaves collected on the island of Mali Lošinj (2.75 mg g(-1) dry weight). Hydroquinone was not detected in any of the samples. The analytical features of the proposed GC-MS method demonstrated that arbutin and hydroquinone could be determined alternatively by gas chromatography. Due to its wide concentration range, the method could also be suitable for arbutin and hydroquinone analysis in leaves of other plant families (Rosaceae, Lamiaceae, etc.). PMID:26444340

  10. Effect of air pollution on trees. VIII. Heavy metals in leaves of street trees: lead nickel, chrome, and cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Maeno, M.

    1971-01-01

    The nickel, lead, chromium, and cadmium contents of leaves of plants grown in Tokyo were measured. The nickel content ranged from 7-15 ppm, the lead content from 14-34 ppm, chromium from 4-16 ppm, and cadmium from 0.7-1.3 ppm. Fluctuations in metal contents were most pronounced for paulownia. High contents of nickel, lead, and chromium were found in highly polluted industrial areas. The differences in lead content in industrial areas compared to that in residential and commercial areas was less significant. This was attributed to the contribution of lead in exhaust gases. Correlation coefficients between metal content and insoluble materials adhering to leaves were calculated for individual plants.

  11. Accuracy of LiDAR-based tree height estimation and crown recognition in a subtropical evergreen broad-leaved forest in Okinawa, Japan

    OpenAIRE

    Azita Ahmad Zawawi; Masami Shiba; Noor Janatun Naim Jemali

    2015-01-01

    Aim of study: To present an approach for estimating tree heights, stand density and crown patches using LiDAR data in a subtropical broad-leaved forest. Area of study: The study was conducted within the Yambaru subtropical evergreen broad-leaved forest, Okinawa main island, Japan. Materials and methods: A digital canopy height model (CHM) was extracted from the LiDAR data for tree height estimation and a watershed segmentation method was applied for the individual crown delineation....

  12. De novo Transcriptome Analysis Reveals Distinct Defense Mechanisms by Young and Mature Leaves of Hevea brasiliensis (Para Rubber Tree).

    Science.gov (United States)

    Fang, Yongjun; Mei, Hailiang; Zhou, Binhui; Xiao, Xiaohu; Yang, Meng; Huang, Yacheng; Long, Xiangyu; Hu, Songnian; Tang, Chaorong

    2016-09-13

    Along with changes in morphology in the course of maturation, leaves of Hevea brasiliensis become more resistant to leaf diseases, including the South American Leaf Blight (SALB), a devastating fungal disease of this economically important tree species. To understand the underlying mechanisms of this defense, and to identify the candidate genes involved, we sequenced the Hevea leaf transcriptome at four developmental stages (I to IV) by Illumina sequencing. A total of 62.6 million high-quality reads were generated, and assembled into 98,796 unique transcripts. We identified 3,905 differentially expressed genes implicated in leaf development, 67.8% (2,651) of which were during the transition to leaf maturation. The genes involved in cyanogenic metabolism, lignin and anthocyanin biosynthesis were noteworthy for their distinct patterns of expression between developing leaves (stages I to III) and mature leaves (stage IV), and the correlation with the change in resistance to SALB and the Oidium/Colletotrichum leaf fall. The results provide a first profile of the molecular events that relate to the dynamics of leaf morphology and defense strategies during Hevea leaf development. This dataset is beneficial to devising strategies to engineer resistance to leaf diseases as well as other in-depth studies in Hevea tree.

  13. De novo Transcriptome Analysis Reveals Distinct Defense Mechanisms by Young and Mature Leaves of Hevea brasiliensis (Para Rubber Tree).

    Science.gov (United States)

    Fang, Yongjun; Mei, Hailiang; Zhou, Binhui; Xiao, Xiaohu; Yang, Meng; Huang, Yacheng; Long, Xiangyu; Hu, Songnian; Tang, Chaorong

    2016-01-01

    Along with changes in morphology in the course of maturation, leaves of Hevea brasiliensis become more resistant to leaf diseases, including the South American Leaf Blight (SALB), a devastating fungal disease of this economically important tree species. To understand the underlying mechanisms of this defense, and to identify the candidate genes involved, we sequenced the Hevea leaf transcriptome at four developmental stages (I to IV) by Illumina sequencing. A total of 62.6 million high-quality reads were generated, and assembled into 98,796 unique transcripts. We identified 3,905 differentially expressed genes implicated in leaf development, 67.8% (2,651) of which were during the transition to leaf maturation. The genes involved in cyanogenic metabolism, lignin and anthocyanin biosynthesis were noteworthy for their distinct patterns of expression between developing leaves (stages I to III) and mature leaves (stage IV), and the correlation with the change in resistance to SALB and the Oidium/Colletotrichum leaf fall. The results provide a first profile of the molecular events that relate to the dynamics of leaf morphology and defense strategies during Hevea leaf development. This dataset is beneficial to devising strategies to engineer resistance to leaf diseases as well as other in-depth studies in Hevea tree. PMID:27619402

  14. Correlation between air pollution and crystal pattern of calcium oxalate in plant leaves of street trees in Itami City. [Ginkgo biloba; Salix babylonica; Aphananthe aspera; Robinia pseudoacacia

    Energy Technology Data Exchange (ETDEWEB)

    Umemoto, K.; Tatsumi, S.

    1975-01-01

    A characteristic difference in calcium oxalate crystal patterns in leaves of roadside trees planted in relatively unpolluted northern parts of Itami City and in parts of the city polluted by automobile exhaust was discovered. The species of trees examined were Ginkgo biloba, Salix babylonica, Aphananthe aspera, Robinia pseudoacacia, and Poplar. The leaves of trees grown in relatively less air polluted areas displayed crystal aggregates of calcium oxalate (50-80 micron) that were arranged in rows on both sides of the central vein; some scattered crystal aggregates between veins were observed. Trees grown in air polluted areas showed irregular crystal patterns and more scattering of the crystals between veins. The cause of the observed differences in the pattern of crystal aggregates was attributed to the difference in metabolism of trees under different environmental conditions. Air pollutants disturb the normal metabolism of the tree and cause hyperproduction of calcium oxalate.

  15. Chemical composition, rumen degradability, protein utilization and lactation response to selected tree leaves as substitute of cottonseed cake in the diet of dairy goats

    NARCIS (Netherlands)

    Khan, N.A.; Habib, G.; Ullah, G.

    2009-01-01

    The aim of this study was to investigate the potential of leaves from Grewia oppositifolia (G. oppositifolia) and Ziziphus mauritiana (Z. mauritiana) as a crude protein (CP) supplements to low quality diets of goats in Pakistan. Chemical composition and CP degradability of the tree leaves were compa

  16. Occurrence of tannins in leaves of beech trees (Fagus sylvatica) along an ecological gradient, detected by histochemical and ultrastructural analyses

    International Nuclear Information System (INIS)

    Sclerophylly and synthesis of phenolic compounds are active responses of plants subjected to environmental stress (drought, low nutrient supply, u.v.-B radiation, ozone). Here we describe the morphological and histochemical alterations occurring in field-grown leaves of Fagus sylvatica L. from three sites located along an ecological gradient: from a site in cool and protected conditions to one located on a mountain ridge, where the trees grow on a thin layer of soil and are exposed to the wind and to intense solar radiation in summer. The morphological data show that, as the ecological conditions of the stand worsen, individual leaf surface decreases, while the thickness of the leaves and their specific d. wt (i.e. d. wt per unit leaf area) increases. Histochemical and ultrastructural tests show a marked increase of phenolics during the course of the year. These substances, present primarily in the leaves of trees growing in stress conditions, have been identified mainly as tannins. They accumulate in the vacuoles, especially those of the upper epidermal layer and the palisade mesophyll; at a later stage they appear to be solubilized in the cytoplasm and retranslocated, eventually impregnating the outer wall of the epidermal cells amidst the cellulose fibrils, where they cluster together and form an electron-opaque layer between the wall and the cuticle. Observation of the epidermal cells also reveals that the outer cell wall is thicker. The paper discusses the roles of secondary metabolites in protection and detoxification processes; the possible ecological significance of these alterations in the ecophysiology of beech trees. (author)

  17. Effect of the air pollution by heavy metals in the tree leaves in the metropolitan area of Toluca Valley

    International Nuclear Information System (INIS)

    Leaves of two tree species: Juniperus sp and Ligustrum sp were studied as indicators of pollution heavy metals (Mn, Fe, Cu, Zn and Pb) in the atmosphere of the Metropolitan Area of the Toluca Valley. Bio markers of catalase, superoxide dismutase, ascorbate peroxidase, guaiacol, proteins and pigments were measured in order to determine the effects to atmospheric stress caused by heave metals during two periods in the year (December 2012 and May 2013). Metals were quantified in dry deposit and tissue on trees tissue leaves using the technique of Energy Dispersive X-ray Fluorescence Spectroscopy and Total Reflection X-ray Fluorescence Spectroscopy respectively. The results show greater response of enzyme inhibition in Juniperus sp. species, with decreased protein content and increased lipid peroxidation at sites with higher content of metals in tissue belonging to urban areas with increased industrial activity and traffic flow. In dry deposit bioavailability factor of metals was Fe>Mn> Zn> Cu>Pb for the first time of sampling and Fe>Mn> Cu> Zn>Pb for the second sampling period. (Author)

  18. Quantitative analysis of arbutin and hydroquinone in strawberry tree (Arbutus unedo L., Ericaceae) leaves by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Jurica, Karlo; Karačonji, Irena Brčić; Šegan, Sandra; Opsenica, Dušanka Milojković; Kremer, Dario

    2015-09-01

    The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine arbutin and hydroquinone content in strawberry tree (Arbutus unedo L., Ericaceae) leaves. The method showed good linearity (R2>0.9987) in the tested concentration range (0.5-200 μg mL(-1)), as well as good precision (RSD<5%), analytical recovery (96.2-98.0%), and sensitivity (limit of detection=0.009 and 0.004 μg mL(-1) for arbutin and hydroquinone, respectively). The results obtained by the validated GC-MS method corresponded well to those obtained by high performance liquid chromatography (HPLC) method. The proposed method was then applied for determining arbutin and hydroquinone content in methanolic leaf extracts. The amount of arbutin in the leaves collected on the island of Koločep (6.82 mg g(-1) dry weight) was found to be higher (tpaired=43.57, tc=2.92) in comparison to the amount of arbutin in the leaves collected on the island of Mali Lošinj (2.75 mg g(-1) dry weight). Hydroquinone was not detected in any of the samples. The analytical features of the proposed GC-MS method demonstrated that arbutin and hydroquinone could be determined alternatively by gas chromatography. Due to its wide concentration range, the method could also be suitable for arbutin and hydroquinone analysis in leaves of other plant families (Rosaceae, Lamiaceae, etc.).

  19. Biomimicry of Palm Tree Leaves Form and Pattern on Building Form

    Directory of Open Access Journals (Sweden)

    Agus Salim N.A.

    2014-01-01

    Full Text Available This article is a study on biomimicry of palm tree towards a building form. It is to find a suitable form and pattern that can be applied to building shell to ease building maintenance operation beside to enhance the aesthetic value of a building architecture. The research has been carried out by observation and modeling on some various species of palm tree’s patterns and forms. The result expectation can be found at the end of this research by producing the best pattern of palm tree that can be adapted to building envelop as the whole form of a building.

  20. Olive Tree (Olea europeae L. Leaves: Importance and Advances in the Analysis of Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Leila Abaza

    2015-11-01

    Full Text Available Phenolic compounds are becoming increasingly popular because of their potential role in contributing to human health. Experimental evidence obtained from human and animal studies demonstrate that phenolic compounds from Olea europaea leaves have biological activities which may be important in the reduction in risk and severity of certain chronic diseases. Therefore, an accurate profiling of phenolics is a crucial issue. In this article, we present a review work on current treatment and analytical methods used to extract, identify, and/or quantify phenolic compounds in olive leaves.

  1. Distinction between injury to tree leaves by ozone and mesophyll-feeding leafhoppers

    Energy Technology Data Exchange (ETDEWEB)

    Hibben, C.R.

    1969-06-01

    The phytotoxic effects of ozone and mesophyll-feeding leafhoppers were contrasted microscopically and histologically on leaves of Acer saccharum Marsh., Quercus rubra L., and Cornus florida L. Injuries induced by the two agents were readily distinguished by the differences in location, configuration, color, and size of the external symptoms, and by the characteristics of affected palisade parenchyma cells.

  2. Urban deciduous tree leaves as biomonitors of trace element (As, V and Cd atmospheric pollution in Belgrade, Serbia

    Directory of Open Access Journals (Sweden)

    KATARINA M. ŠUĆUR

    2010-10-01

    Full Text Available Leaves of common deciduous trees: horse chestnut (Aesculus hippocastanum and linden (Tilia spp. from three parks within the urban area of Belgrade were studied as biomonitors of trace element (As, V, and Cd atmospheric pollution. The May–September trace element accumulation in the leaves, and their temporal trends, were assayed in a multi-year period (2002–2006. Significant accumulation in the leaves was evident for As and V, but not so regularly for Cd. Slightly decreasing temporal trends of V and As ac-cumulated in the leaf tissues were observed over the years. During the time span, the concentrations of Cd remained approximately on the same level, except in May 2002 and September 2005, when a rapid increase was observed. The May–September accumulations of As and V were higher in horse chestnut than in linden, although both may be used as biomonitors for these elements, and optionally for Cd in conditions of its high atmospheric loadings.

  3. Olive Tree (Olea europeae L.) Leaves: Importance and Advances in the Analysis of Phenolic Compounds

    OpenAIRE

    Leila Abaza; Amani Taamalli; Houda Nsir; Mokhtar Zarrouk

    2015-01-01

    Phenolic compounds are becoming increasingly popular because of their potential role in contributing to human health. Experimental evidence obtained from human and animal studies demonstrate that phenolic compounds from Olea europaea leaves have biological activities which may be important in the reduction in risk and severity of certain chronic diseases. Therefore, an accurate profiling of phenolics is a crucial issue. In this article, we present a review work on current treatment and analyt...

  4. Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES

    Institute of Scientific and Technical Information of China (English)

    Jianrong Zeng; Guilin Zhang; Liangman Bao; Shilei Long; Mingguang Tan; Yan Li; Chenyan Ma

    2013-01-01

    Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmentalbiology.A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy wasestablished to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs),which were sampled from 5 localfields in Shanghai,China.Annual SO2 concentration,SO42-concentration in atmospheric particulate,SO42-and sulfur concentrationin soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs.Totalsulfur concentration in mature camphor tree leaves was 766-1704 mg/kg.The mainly detected sulfur states and their correspondingcompounds were +6 (sulfate,include inorganic sulfate and organic sulfate),+5.2 (sulfonate),+2.2 (suloxides),+0.6 (thiols andthiothers),+0.2 (organic sulfides).Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlationcoefficient up to 0.977,which suggested that sulfur accumulated in CTLs as sulfate form.Reduced sulfur compounds (organic sulfides,thiols,thioethers,sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced levelaround 526 mg/kg.The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulateinstead of soil contamination.From urban to suburb place,sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced,but a dramatic increase presented near the seashore,where the marine sulfate emission and maritime activity pollution were significant.The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmosphericsulfur pollution in local environment.

  5. Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES.

    Science.gov (United States)

    Zeng, Jianrong; Zhang, Guilin; Bao, Liangman; Long, Shilei; Tan, Mingguang; Li, Yan; Ma, Chenyan; Zhao, Yidong

    2013-03-01

    Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmental biology. A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy was established to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs), which were sampled from 5 local fields in Shanghai, China. Annual SO2 concentration, SO4(2-) concentration in atmospheric particulate, SO4(2-) and sulfur concentration in soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs. Total sulfur concentration in mature camphor tree leaves was 766-1704 mg/kg. The mainly detected sulfur states and their corresponding compounds were +6 (sulfate, include inorganic sulfate and organic sulfate), +5.2 (sulfonate), +2.2 (suloxides), +0.6 (thiols and thiothers), +0.2 (organic sulfides). Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlation coefficient up to 0.977, which suggested that sulfur accumulated in CTLs as sulfate form. Reduced sulfur compounds (organic sulfides, thiols, thioethers, sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced level around 526 mg/kg. The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulate instead of soil contamination. From urban to suburb place, sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced, but a dramatic increase presented near the seashore, where the marine sulfate emission and maritime activity pollution were significant. The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmospheric sulfur pollution in local environment. PMID:23923435

  6. Assessment of the urban trees health status on the base of nutrient and pigment content in their leaves

    Directory of Open Access Journals (Sweden)

    SLAVEYA PETROVA

    2014-04-01

    Full Text Available Town settlements have different load level by emissions originated mostly from transport, industry and heating system. Their environmental and climate conditions are more or less changed that effect to growth, physiology and vigor of woody plants at the city public vegetation areas. Our study on determining the impact of urban environment on the tree health status was focused on the quantities of nutrients and main components of the pigment complex – chlorophyll a, chlorophyll b and carotenoids. Leaves of Acer platanoides L., Aesculus hippocastanum L. and Betula pendula Roth. were sampled from urban areas with different type of anthropogenic pressure in the town of Plovdiv (Bulgaria. Concentrations of the elements Ca, K, Mg, N, Na, P, and S were analyzed by ICP-MS. Health condition of trees in the city parks and suburban areas was acceptable, but in the central part and close to the industrial area it was non-satisfactory. This preliminary research pointed ecophysiological tools as useful to develop new criteria for sustainable urban arboriculture, including species selection (based on stress tolerance criteria, nursery hardening and preconditioning, and care after planting.

  7. Trees

    Science.gov (United States)

    Al-Khaja, Nawal

    2007-01-01

    This is a thematic lesson plan for young learners about palm trees and the importance of taking care of them. The two part lesson teaches listening, reading and speaking skills. The lesson includes parts of a tree; the modal auxiliary, can; dialogues and a role play activity.

  8. Caloric content of leaves of five tree species from the riparian vegetation in a forest fragment from South Brazil

    Directory of Open Access Journals (Sweden)

    Leandro Fabrício Fiori

    2015-09-01

    Full Text Available Abstract Aim: The measurement of the caloric content evidences the amount of energy that remains in the leaf and that can be released to the aquatic trophic chain. We assessed the energy content of leaves from five riparian tree species of a forest fragment in south Brazil and analyzed whether leaf caloric content varied between leaf species and between seasons (dry and wet. The studied sites are located in Northwest of Paraná State, inside a Semi-Deciduous Forest fragment beside two headwater streams. Methods Sampling sites were located along the riparian vegetation of these two water bodies, and due to its proximity and absence of statistical differences of caloric values, analyzed as one compartment. Results Caloric content varied significantly among species and among all pairs of species, with exception of Nectandra cuspidata Ness and Calophyllum brasiliensis Cambess. Two species presented significant differences between seasons, Sloanea guianensis (Aubl. Ben and Calophyllum brasiliensis Cambess. Conclusions The absence of significant seasonal differences of energy content for some species may be due to the characteristics of the tropical forest, in which temperature did not varied dramatically between seasons. However, the energy differed between species and seasons for some species, emphasizing the necessity of a preliminary inspection of energy content, before tracing energy fluxes instead of using a single value to all species from riparian vegetation.

  9. Lead and cadmium in leaves of deciduous trees in Beijing, China: Development of a metal accumulation index (MAI)

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yanju [Beijing Center for Physical and Chemical Analysis, Beijing 100089 (China) and Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)]. E-mail: liuyanju@hotmail.com; Zhu Yongguan [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Ding Hui [Beijing Center for Physical and Chemical Analysis, Beijing 100089 (China)

    2007-01-15

    Lead and cadmium uptake was investigated for common deciduous street trees in Beijing in this study. Species having Cd accumulation included Populus tomentosa, Sophora japonica and Catalpa speciosa. P. tomentosa had the highest ratios between leaf and soil Cd (0.848), followed by S. japonica (0.536), C. speciosa (0.493), Paulownia tomentosa (0.453) and Juglans regia (0.415). Pb levels were high in leaves of C. speciosa, J. regia and Pa. tomentosa. S. japonica had the highest ratio between leaf Pb and soil Pb (0.146), followed by Pa. tomentosa (0.143), Ginko biloba (0.103) and C. speciosa (0.095). A predictive foliar metal accumulation index (MAI) was developed and C. speciosa was calculated to have the highest MAI value (53.8). This suggests that C. speciosa would be a good choice for planting in areas of Beijing where soil contamination with Cd and Pb may be a problem. - Catalpa speciosa had the highest MAI value.

  10. Isolation, Structural Characterization, and Valorization of Pectic Substances from Algerian Argan Tree Leaves (Argania spinosa (L. Skeels

    Directory of Open Access Journals (Sweden)

    Kadda Hachem

    2015-01-01

    Full Text Available Pectic polysaccharides were solubilized from Algerian argan tree leaves by sequential extraction with water at 100°C (water-soluble pectin; AL-WSP and EDTA solution at 80°C (chelating-soluble pectin; AL-CSP. Both AL-WSP and AL-CSP were rich in arabinose (28% and 74.5%, resp. and had a high content of uronic acid (38.5% and 21.5%, resp.. Pectic substances were deesterified and fractionated by anion exchange chromatography, giving five fractions for each extract. Most of the fractions were characterized by methylation analysis and then analyzed by 13C nuclear magnetic resonance spectroscopy. The results showed that AL-WSP consisted of rhamnogalacturonan type I, with arabinan and galactan branching at the O-4 position of the main rhamnose chain, while AL-CSP consisted of rhamnogalacturonan type I and a block of homogalacturonan. Antioxidant activities of AL-WSP and AL-CSP were evaluated by electronic spin resonance. The results showed that the antioxidant potential of AL-WSP (8.1% and AL-CSP (−1.2% was significantly lower than that of vitamin E.

  11. Lead and cadmium in leaves of deciduous trees in Beijing, China: development of a metal accumulation index (MAI).

    Science.gov (United States)

    Liu, Yan-Ju; Zhu, Yong-Guan; Ding, Hui

    2007-01-01

    Lead and cadmium uptake was investigated for common deciduous street trees in Beijing in this study. Species having Cd accumulation included Populus tomentosa, Sophora japonica and Catalpa speciosa. P. tomentosa had the highest ratios between leaf and soil Cd (0.848), followed by S. japonica (0.536), C. speciosa (0.493), Paulownia tomentosa (0.453) and Juglans regia (0.415). Pb levels were high in leaves of C. speciosa, J. regia and Pa. tomentosa. S. japonica had the highest ratio between leaf Pb and soil Pb (0.146), followed by Pa. tomentosa (0.143), Ginko biloba (0.103) and C. speciosa (0.095). A predictive foliar metal accumulation index (MAI) was developed and C. speciosa was calculated to have the highest MAI value (53.8). This suggests that C. speciosa would be a good choice for planting in areas of Beijing where soil contamination with Cd and Pb may be a problem. PMID:16797111

  12. Lead and cadmium in leaves of deciduous trees in Beijing, China: Development of a metal accumulation index (MAI)

    International Nuclear Information System (INIS)

    Lead and cadmium uptake was investigated for common deciduous street trees in Beijing in this study. Species having Cd accumulation included Populus tomentosa, Sophora japonica and Catalpa speciosa. P. tomentosa had the highest ratios between leaf and soil Cd (0.848), followed by S. japonica (0.536), C. speciosa (0.493), Paulownia tomentosa (0.453) and Juglans regia (0.415). Pb levels were high in leaves of C. speciosa, J. regia and Pa. tomentosa. S. japonica had the highest ratio between leaf Pb and soil Pb (0.146), followed by Pa. tomentosa (0.143), Ginko biloba (0.103) and C. speciosa (0.095). A predictive foliar metal accumulation index (MAI) was developed and C. speciosa was calculated to have the highest MAI value (53.8). This suggests that C. speciosa would be a good choice for planting in areas of Beijing where soil contamination with Cd and Pb may be a problem. - Catalpa speciosa had the highest MAI value

  13. Photoprotection of evergreen and drought-deciduous tree leaves to overcome the dry season in monsoonal tropical dry forests in Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Yamazaki, Jun-Ya; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Maruta, Emiko; Diloksumpun, Sapit; Puangchit, Ladawan

    2014-01-01

    In tropical dry forests, uppermost-canopy leaves of evergreen trees possess the ability to use water more conservatively compared with drought-deciduous trees, which may result from significant differences in the photoprotective mechanisms between functional types. We examined the seasonal variations in leaf gas exchange, chlorophyll fluorescence and the amounts of photosynthetic pigments within lamina of the uppermost-canopy leaves of three drought-deciduous trees (Vitex peduncularis Wall., Xylia xylocarpa (Roxb.) W. Theob., Shorea siamensis Miq.), a semi-deciduous tree (Irvingia malayana Miq.) and two evergreen trees (Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels) in Thailand. Area-based maximum carbon assimilation rates (Amax) decreased during the dry season, except in S. siamensis. The electron transport rate (ETR) remained unchanged in deciduous trees, but decreased during the dry season in evergreen and semi-deciduous trees. In the principal component analysis, the first axis (Axis 1) accounted for 44.3% of the total variation and distinguished deciduous from evergreen trees. Along Axis 1, evergreen trees were characterized by a high Stern-Volmer non-photochemical quenching coefficient (NPQ), high xanthophyll cycle pigments/chlorophyll and a high de-epoxidation state of the xanthophyll cycle, whereas the deciduous trees were characterized by a high ETR, a high quantum yield of PSII (ΦPSII = (Fm(') -F)/Fm(')) and a high mass-based Amax under high-light conditions. These findings indicate that drought-deciduous trees showing less conservative water use tend to dissipate a large proportion of electron flow through photosynthesis or alternative pathways. In contrast, the evergreens showed more conservative water use, reduced Amax and ETR and enhanced NPQ and xanthophyll cycle pigments/chlorophyll during the dry season, indicating that down-regulated photosynthesis with enhanced thermal dissipation of excess light energy played an important role in

  14. Photoprotection of evergreen and drought-deciduous tree leaves to overcome the dry season in monsoonal tropical dry forests in Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Yamazaki, Jun-Ya; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Maruta, Emiko; Diloksumpun, Sapit; Puangchit, Ladawan

    2014-01-01

    In tropical dry forests, uppermost-canopy leaves of evergreen trees possess the ability to use water more conservatively compared with drought-deciduous trees, which may result from significant differences in the photoprotective mechanisms between functional types. We examined the seasonal variations in leaf gas exchange, chlorophyll fluorescence and the amounts of photosynthetic pigments within lamina of the uppermost-canopy leaves of three drought-deciduous trees (Vitex peduncularis Wall., Xylia xylocarpa (Roxb.) W. Theob., Shorea siamensis Miq.), a semi-deciduous tree (Irvingia malayana Miq.) and two evergreen trees (Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels) in Thailand. Area-based maximum carbon assimilation rates (Amax) decreased during the dry season, except in S. siamensis. The electron transport rate (ETR) remained unchanged in deciduous trees, but decreased during the dry season in evergreen and semi-deciduous trees. In the principal component analysis, the first axis (Axis 1) accounted for 44.3% of the total variation and distinguished deciduous from evergreen trees. Along Axis 1, evergreen trees were characterized by a high Stern-Volmer non-photochemical quenching coefficient (NPQ), high xanthophyll cycle pigments/chlorophyll and a high de-epoxidation state of the xanthophyll cycle, whereas the deciduous trees were characterized by a high ETR, a high quantum yield of PSII (ΦPSII = (Fm(') -F)/Fm(')) and a high mass-based Amax under high-light conditions. These findings indicate that drought-deciduous trees showing less conservative water use tend to dissipate a large proportion of electron flow through photosynthesis or alternative pathways. In contrast, the evergreens showed more conservative water use, reduced Amax and ETR and enhanced NPQ and xanthophyll cycle pigments/chlorophyll during the dry season, indicating that down-regulated photosynthesis with enhanced thermal dissipation of excess light energy played an important role in

  15. Autoencoder Trees

    OpenAIRE

    İrsoy, Ozan; Alpaydın, Ethem

    2014-01-01

    We discuss an autoencoder model in which the encoding and decoding functions are implemented by decision trees. We use the soft decision tree where internal nodes realize soft multivariate splits given by a gating function and the overall output is the average of all leaves weighted by the gating values on their path. The encoder tree takes the input and generates a lower dimensional representation in the leaves and the decoder tree takes this and reconstructs the original input. Exploiting t...

  16. Ethanol Extract of Persimmon Tree Leaves Improves Blood Circulation and Lipid Metabolism in Rats Fed a High-Fat Diet

    Science.gov (United States)

    Ryu, Ri; Kim, Hye-Jin; Moon, Byeongseok; Jung, Un Ju; Lee, Mi-Kyung; Lee, Dong Gun; Ryoo, ZaeYoung; Park, Yong Bok

    2015-01-01

    Abstract The leaves of the persimmon tree (PL) are known to have beneficial effects on hyperglycemia, dyslipidemia, and nonalcoholic fatty liver disease. We recently demonstrated that PL had antithrombotic properties in vitro. However, little is known about the antiplatelet and anticoagulant properties of PL in vivo. Omega-3 fatty acid (n-3 FA)-containing fish oil has been widely prescribed to improve blood circulation. This study compared the effects of dietary supplementation with an ethanol extract of PL or n-3 FA on blood coagulation, platelet activation, and lipid levels in vivo. Sprague–Dawley rats were fed a high-fat diet with either PL ethanol extract (0.5% w/w) or n-3 FA (2.5% w/w) for 9 weeks. Coagulation was examined by monitoring the activated partial thromboplastin time (aPTT) and prothrombin time. We examined plasma thromboxane B2 (TXB2), serotonin, and soluble P-selectin (sP-selectin) levels. The aPTT was significantly prolonged in the PL and n-3 FA supplement groups. PL also attenuated the TXB2 level and lowered arterial serotonin transporter mRNA expression, although it did not alter plasma serotonin or sP-selectin levels. C-reactive protein and leptin levels were significantly reduced by PL and n-3 FA supplementation. In addition, PL decreased plasma total- and low-density lipoprotein-cholesterol levels, as did n-3 FA treatment. These results indicated that the PL ethanol extract may have the potential to improve circulation by inhibiting blood coagulation and platelet activation and by reducing plasma cholesterol levels. PMID:26061228

  17. Determination of mass attenuation coefficient in wood and leaves of typical trees by gamma-ray attenuation technique

    International Nuclear Information System (INIS)

    Using an 241 Am source the mass attenuation coefficient of different woods and leaves of typical species of the Atlantic Forest were measured. The results for natural wood, dry wood and dry leaves indicate that the variation is very small among different species. However, woods present a higher attenuation than leaves, both depending on their water content. (author). 10 refs., 3 figs., 1 tab

  18. Wybrane zagadnienia z morfogenezy liści drzew. II. Występowanie młodocianych form liści w koronach drzew buka zwyczajnego (Fagus silvatica L. [Studies on the mohprogenesis of tree-leaves. II. The occurrence of juvenile forms of leaves in the crowns of beech trees (Fagus silvatica L.

    Directory of Open Access Journals (Sweden)

    I. Więckowska

    2015-05-01

    Full Text Available It was fairly often observed that Fagus silvatica L. leafed twice during one vegetational season. This secondary growth occurred on all trees, when the first leaves underwent destruction, e.g. in consequence of late spring frost. The leaves of secondary growth differed pronouncedly from normally developed ones by their shape and irregular nervation and were similar to the juvenile leaves of one-year-old seedlings of beech. Observations of leaf buds showed that the nerves appeared in leaf-primordia of Fagus silvatica as late as the latter part of July and if the secondary leaves developed at the end of July, they were normal in shape and bad regular nervation. Leaf-primordia compelled to an earlier development gave leaves of different form and irregular nervation.

  19. Trees

    CERN Document Server

    Epstein, Henri

    2016-01-01

    An algebraic formalism, developped with V.~Glaser and R.~Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large category of space-times.

  20. Carbonic anhydrase activity and photosynthetic rate in the tree species Paulownia tomentosa Steud. Effect of dimethylsulfoxide treatment and zinc accumulation in leaves.

    Science.gov (United States)

    Lazova, Galia N; Naidenova, Tsveta; Velinova, Katya

    2004-03-01

    The enzyme carbonic anhydrase (CA) (EC 4.2.1.1) catalyzes the reversible conversion of CO2 to HCO3- and has been shown to be involved in photosynthesis. The enzyme has been shown in animals, plants, eubacteria and viruses, but similar reports on the evidence for CA activity in tree plants does not be appear to be available. In the preliminary analyses of the work, the CA activity in leaf extracts from the tree species Paulownia tomentosa Steud. (introduced in Bulgaria) is described. A connection between CA activity and the rate of photosynthetic CO2 fixation is shown. In the second portion of the work, the effect of 10(-4) mol/L and 10(-2) mol/L dimethylsulfoxide (DMSO) on the zinc accumulation in leaves is demonstrated. It is suggested that CA activity is an indicator of the level of physiologically active zinc in leaves of P. tomentosa Steud. A connection between the process of zinc accumulation in leaves and the activity of the enzymes CA and glycolate oxidase (GO) (EC 1.1.3.1) is established. PMID:15077628

  1. Nitrogen storage and distribution and reuse of 15N-urea applied in autumn on different branch leaves of winter Jujube (Zizyphus jujuba Mill. var. inermis Rehd) trees

    International Nuclear Information System (INIS)

    The effectiveness of foliage spraying with urea to augment the seasonal internal cycling of N in winter Jujube was studied. Different branches leaves of 6-year-old trees were painted with 5% abundance of 15N-urea solution after fruit harvesting. Results showed that 15N was detected in all the tree organs during the dormant season. In the following year 15N was also detected in new growth organs (deciduous spurs, leaves and flowers). The treated branches and adjacent organs were the main sinks of Nitrogen in the dormant season. Ndff% in the treated branches was significantly decreased during dormant season. And a decrease of 59.13% was observed in the new growth branch treated and 60.05% in the perennial branches. Reserved nitrogen was reused for initial growth (leaves and deciduous spurs). 15N stored in perennial organs also remobilized to sustain new growth of treated branches. It is different from the treated new growth branch, 15N stored in the treated perennial branches is not only transported for new organs growth, but also for roots growth. (authors)

  2. Synthesis, Characterization, and Catalytic Activity of Sulfonated Carbon-Based Catalysts Derived From Rubber Tree Leaves and Pulp and Paper Mill Waste

    Science.gov (United States)

    Janaun, J.; Sinin, E.; Hiew, S. F.; Kong, A. M. T.; Lahin, F. A.

    2016-06-01

    Sulfonated carbon-based catalysts derived from rubber tree leaves, and pulp and paper mill waste were synthesized and characterized. Three types of catalyst synthesized were sulfonated rubber tree leaves (S-RTL), pyrolysed sludge char (P-SC) and sulfonated sludge char (S-SC). Sulfonated rubber tree leaves (S-RTL) and sulfonated sludge char (S-SC) were prepared through pyrolysis followed by functionalization via sulfonation process whereas, P- SC was only pyrolyzed without sulfonation. The characterization results indicated sulfonic acids, hydroxyl, and carboxyl moieties were detected in S-RTL and S-SC, but no sulfonic acid was detected in P-SC. Total acidity test showed S-RTL had the highest value followed by S-SC and P-SC. The thermal stability of S-RTL and S-SC were up to 230oC as the loss was associated with the decomposition of sulfonic acid group, whereas, P-SC showed higher stability than the S-RTL and S-SC. Morphology analysis showed that S-RTL consisted of an amorphous carbon structure, and a crystalline structure for P-SC and S-SC. Furthermore, traces of metal components were also detected on all of the catalysts. The catalyst catalytic activity was tested through esterification of oleic acid with methanol. The results showed that the reaction using S-RTL catalyst produced the highest conversion (99.9%) followed by P-SC (88.4%) and lastly S-SC (82.7%). The synthesized catalysts showed high potential to be used in biodiesel production.

  3. On the relation between tree crown morphology and particulate matter deposition on urban tree leaves: a ground-based LiDAR approach

    NARCIS (Netherlands)

    Hofman, J.; Bartholomeus, H.; Calders, K.; Wittenberghe, van S.; Wuyts, K.; Samson, R.

    2014-01-01

    Urban dwellers often breathe air that does not meet the European and WHO standards. Next to legislative initiatives to lower atmospheric pollutants, much research has been conducted on the potential of urban trees as mitigation tool for atmospheric particles. While leaf-deposited dust has shown to v

  4. Vegetative propagation of Quercus suber L. by somatic embryogenesis. I. Factors affecting the induction in leaves from mature cork oak trees.

    Science.gov (United States)

    Hernández, I; Celestino, C; Toribio, M

    2003-04-01

    Somatic embryogenesis was induced in expanding leaves from epicormic shoots forced to sprout from segments of branches collected from several hundred-year-old cork oak trees. Following a basic protocol previously defined for leaves taken from seedlings of this species, several factors were studied to improve the response. The induction frequency was significantly higher when the length of exposure to growth regulators was increased from 7 to 30 days. The combined application of NAA and BAP was essential for induction. Although both regulators had a very significant influence, their interaction was not significant, suggesting independent roles. Leaf size had a crucial effect, because beyond a certain threshold, embryogenesis could not be obtained. Embryogenic lines were maintained via repetitive embryogenesis on hormone-free medium for more than 2 years.

  5. Comparative study on disappearance trends of captan and trifloxystrobin residues on fruit and apple tree leaves using internal normalisation method.

    Science.gov (United States)

    Sadło, Stanisław; Duda, Magdalena; Piechowicz, Bartosz; Jaźwa, Agnieszka

    2013-01-01

    Supervised field trials were carried out in a commercial orchard in 2011. The purpose of the study was to assess the usefulness of the comparative method to examine the mechanism of disappearance of pesticide residues. Captan and trifloxystrobin residues were determined with the use of gas chromatograph equipped with a micro-electron capture detector. Disappearance trends of captan and trifloxystrobin residues in fruit and leaves were estimated using the method of internal normalisation, and based on that, the courses of concentration changes of these substances on fruit and leaves and the amount of these substances in one apple were established. The initial deposits of trifloxystrobin on leaves and fruits dropped by 50% within 8 and 4 days after treatment, respectively, in both varieties, whereas captan residues dropped by 50% within 29 days in leaves and 7 days in apples of the Olive Yellow varieties.

  6. Spatial distribution of anthropogoenic pollution acumulated on tree leaves, soil and street dust in the park area in the centre of Warsaw

    Science.gov (United States)

    Dytłow, Sylwia; Górka-Kostrubiec, Beata

    2015-04-01

    The magnetic method has been successfully used to evaluate and characterise the degree of air pollution. This method is based on investigation of properties of magnetic particles of pollution such as magnetic susceptibility, parameters of hysteresis loops and temperature-dependence of magnetic parameters etc. The motivation to undertake this study was to find the distribution of pollution emitted by traffic vehicles in a green area situated in urban environment. The investigated area is the oldest public park named Saxon Garden in the centre of Warsaw, Poland. The Saxon Garden is located between the very busy main road with tram line, two local streets (low traffic volume) and big plaza without car traffic and trees. In order to quantify the degree of pollution we measured magnetic susceptibility of pollution deposited on chestnut leaves (the most abundant tree species in the park), surface of the roads (street dust) and in soil from the park area. The highest values of magnetic susceptibility of pollution were observed on tree leaves located along the edges/borders of park area (190 [m3/kg]), directly adjacent to busy roads. The lowest values of magnetic susceptibility (20 [m3/kg]) were obtained for leave samples from the borders of park, directly adjacent to plaza and roads with low traffic volume. It was observed that the intensity of magnetic susceptibility decreases with the distance of pollution source i.e. main streets. A similar distribution of intensity of magnetic susceptibility was observed for the soil samples collected from park area. With the exception of a few samples, the magnetic susceptibility of soil samples were higher than for leave samples. Our study showed that the distribution of magnetic susceptibility of soil and leave samples correlate with the intensity of magnetic susceptibility of street dust taken from the road surfaces situated along the boundary of the park area. On the basis of the detailed research of the domain structure and

  7. Environmental Correlates of Distribution of the 25 Broad-leaved Tree Species Indigenous to Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    Su Zhiyao; Chen Beiguang; Chang Yong; Yang Jiazhi

    2004-01-01

    Twenty-five tree species indigenous to Guangdong Province were chosen in this study to portray their distribution patterns in relation to environmental factors. Both data of species distribution and environmental factors were tabulated based on a digitized map of Guangdong Province gridded at 0.5° latitude × 0.5° longitude. Grid-based diversity was mapped using DMAP, a distribution mapping program, and horizontal patterns were assessed using Kruskal-Wallis tests. The diversity center of the indigenous tree species under study is located north of 23° N. These tree species exhibit significant latitudinal variation (P = 0.007 4), but no significant longitudinal difference (P = 0.052 2). Non-metric Multidimensional Scaling (NMS) identified five different ecological species groups, while Canonical Correspondence Analysis (CCA) showed the distribution of tree species along each of the five environmental gradients. An understanding of the environmental correlates of distribution patterns has great implication for the introduction of the indigenous tree species for afforestation.

  8. DIVERSITY AND ECOLOGICAL DETERMINANTS OF DEAD WOOD FUNGI IN TREE NATURAL RESERVES OF BROAD LEAVED FORESTS FROM SUCEAVA COUNTY

    Directory of Open Access Journals (Sweden)

    Ciprian BÎRSAN

    2014-12-01

    Full Text Available Dead wood fungi have a major importance for forests biodiversity as they produce wood degradation in forest habitats. In this paper are presented some aspects related to the diversity of dead wood fungi in tree deciduous forest types from tree natural reserves (Crujana, Dragomirna and Zamostea from Suceava County and the effect of some ecological factors (host tree, diameter and decomposition degree of the dead wood and some microclimatic characteristics of sites on their occurrence and diversity. Investigations carried out in 2013 resulted in the identification of 44 lignicolous fungi species. Analysis of similarities between lingnicolous fungi species from the investigated natural reserves (by hierarchical clustering shows a separation of three fungi groups, depending on the host-trees species. The effect of the tree host species was highlighted also by detrended correspondence analysis, which, in addition presented the existence of an altitudinal gradient and a weaker effect of site conditions (slope and aspect and microclimatic variables (solar radiation on dead wood fungi occurrence. The effect of diameter and decomposition degree of fallen trunks and branches on dead wood fungi species was investigated using the redundancy analysis showing that wood debris with large surfaces are more easily colonized by the fungi species developing large sporocarps compared to small branches with low diameters colonized only by few or a single fungus species.

  9. Tree age-dependent changes in photosynthetic and respiratory CO2 exchange in leaves of micropropagated diploid, triploid and hybrid aspen.

    Science.gov (United States)

    Pärnik, Tiit; Ivanova, Hiie; Keerberg, Olav; Vardja, Rael; Niinemets, Ulo

    2014-06-01

    The growth rate of triploid European aspen (Populus tremula L.) and hybrid aspen (P. tremula × Populus tremuloides Michx.) significantly exceeds that of diploid aspen, but the underlying physiological controls of the superior growth rates of these genotypes are not known. We tested the hypothesis that the superior growth rate of triploid and hybrid aspen reflects their greater net photosynthesis rate. Micropropagated clonal plants varying in age from 2.5 to 19 months were used to investigate the ploidy and plant age interaction. The quantum yield of net CO2 fixation (Φ) in leaves of young 2.5-month-old hybrid aspen was lower than that of diploid and triploid trees. However, Φ in 19-month-old hybrid aspen was equal to that in triploid aspen and higher than that in diploid aspen. Φ and the rate of light-saturated net photosynthesis (ANS) increased with plant age, largely due to higher leaf dry mass per unit area in older plants. ANS in leaves of 19-month-old trees was highest in hybrid, medium in triploid and lowest in diploid aspen. Light-saturated photosynthesis had a broad temperature optimum between 20 and 35 °C. Rate of respiration in the dark (RDS) did not vary among the genotypes in 2.5-month-old plants, and the shape of the temperature response was also similar. RDS increased with plant age, but RDS was still not significantly different among the leaves of 19-month-old diploid and triploid aspen, but it was significantly lower in leaves of 19-month-old hybrid plants. The initial differences in the growth of plants with different ploidy were minor up to the age of 19 months, but during the next 2 years, the growth rate of hybrid aspen exceeded that of triploid plants by 2.7 times and of diploid plants by five times, in line with differences in ANS of 19-month-old plants of these species. It is suggested that differences in photosynthesis and growth became more pronounced with tree aging, indicating that ontogeny plays a key role in the expression of

  10. Seasonal and yearly variations in light use and nitrogen use by seedlings of four deciduous broad-leaved tree species invading larch plantations.

    Science.gov (United States)

    Kitaoka, Satoshi; Koike, Takayoshi

    2005-04-01

    Several deciduous broad-leaved tree species, differing in leaf phenology, invade larch (Larix kaempferii (Lamb.) Carrière) plantations in Japan. The understory light environment of larch forests changes drastically between the leafy and leafless periods. To determine how the invading seedlings exploit the changing light environment, and if phenological differences reflect the light- and nitrogen-use traits of the seedlings, we measured leaf phenology, seasonal changes in light-saturated photosynthetic rate (P(sat)), leaf nitrogen (N) content (N(area)), chlorophyll/nitrogen ratio (Chl/N), specific leaf area (SLA) and N remobilization rate (NRMR) over 3 years. The mid-successional or gap-phase species, Magnolia hypoleuca Siebold & Zucc., had a short leafy period and high P(sat) and NRMR. In contrast, two late-successional tree species, Prunus ssiori Friedr. Schmidt, which undergoes leaf flush before larch, and Carpinus cordata Blume, which maintains green leaves until frost, both had low P(sat) and NRMR but exploited the opportunity for growth during the period when the larch canopy trees were leafless. Quercus mongolica Fisch. ex Ledeb. var. crispula (Blume) Ohashi, a mid-late-successional species that underwent leaf flush at the same time as the overstory larch, had values of photosynthetic parameters between those of the gap-phase and late-successional species. Among species, M. hypoleuca and Q. mongolica had higher photosynthetic rates and photosynthetic N-use efficiencies. In all species, the relationship between N(area) and P(sat) showed species-specific yearly fluctuations; however, there was no yearly fluctuation in the relationship between N(area) and P(sat) at CO2 saturation. Yearly fluctuations in the N(area)-P(sat) relationship appeared to be induced by changes in SLA and N-use characteristics, which in turn are affected by climatic variations.

  11. Isolation of high quality and polysaccharide-free DNA from leaves of Dimorphandra mollis (Leguminosae), a tree from the Brazilian Cerrado.

    Science.gov (United States)

    Souza, H A V; Muller, L A C; Brandão, R L; Lovato, M B

    2012-03-22

    Dimorphandra mollis (Leguminosae), known as faveiro and fava d'anta, is a tree that is widely distributed throughout the Brazilian Cerrado (a savanna-like biome). This species is economically valuable and has been extensively exploited because its fruits contain the flavonoid rutin, which is used to produce medications for human circulatory diseases. Knowledge about its genetic diversity is needed to guide decisions about the conservation and rational use of this species in order to maintain its diversity. DNA extraction is an essential step for obtaining good results in a molecular analysis. However, DNA isolation from plants is usually compromised by excessive contamination by secondary metabolites. DNA extraction of D. mollis, mainly from mature leaves, results in a highly viscous mass that is difficult to handle and use in techniques that require pure DNA. We tested four protocols for plant DNA extraction that can be used to minimize problems such as contamination by polysaccharides, which is more pronounced in material from mature leaves. The protocol that produced the best DNA quality initially utilizes a sorbitol buffer to remove mucilaginous polysaccharides. The macerated leaf material is washed with this buffer until there is no visible mucilage in the sample. This protocol is adequate for DNA extraction both from young and mature leaves, and could be useful not only for D. mollis but also for other species that have high levels of polysaccharide contamination during the extraction process.

  12. Variability in radial sap flux density patterns and sapwood area among seven co-occurring temperate broad-leaved tree species.

    Science.gov (United States)

    Gebauer, Tobias; Horna, Viviana; Leuschner, Christoph

    2008-12-01

    Forest transpiration estimates are frequently based on xylem sap flux measurements in the outer sections of the hydro-active stem sapwood. We used Granier's constant-heating technique with heating probes at various xylem depths to analyze radial patterns of sap flux density in the sapwood of seven broad-leaved tree species differing in wood density and xylem structure. Study aims were to (1) compare radial sap flux density profiles between diffuse- and ring-porous trees and (2) analyze the relationship between hydro-active sapwood area and stem diameter. In all investigated species except the diffuse-porous beech (Fagus sylvatica L.) and ring-porous ash (Fraxinus excelsior L.), sap flux density peaked at a depth of 1 to 4 cm beneath the cambium, revealing a hump-shaped curve with species-specific slopes. Beech and ash reached maximum sap flux densities immediately beneath the cambium in the youngest annual growth rings. Experiments with dyes showed that the hydro-active sapwood occupied 70 to 90% of the stem cross-sectional area in mature trees of diffuse-porous species, whereas it occupied only about 21% in ring-porous ash. Dendrochronological analyses indicated that vessels in the older sapwood may remain functional for 100 years or more in diffuse-porous species and for up to 27 years in ring-porous ash. We conclude that radial sap flux density patterns are largely dependent on tree species, which may introduce serious bias in sap-flux-derived forest transpiration estimates, if non-specific sap flux profiles are assumed.

  13. Assessment of the urban trees health status on the base of nutrient and pigment content in their leaves

    OpenAIRE

    SLAVEYA PETROVA; LILYANA YURUKOVA; ILIANA VELCHEVA

    2014-01-01

    Town settlements have different load level by emissions originated mostly from transport, industry and heating system. Their environmental and climate conditions are more or less changed that effect to growth, physiology and vigor of woody plants at the city public vegetation areas. Our study on determining the impact of urban environment on the tree health status was focused on the quantities of nutrients and main components of the pigment complex – chlorophyll a, chlorophyll b and carotenoi...

  14. Natural isotopes abundance of 15N and 13C in leaves of some N2-fixing and non N2-fixing trees and shrubs in Syria

    International Nuclear Information System (INIS)

    Variability in the natural abundance isotopes of 15N and 13C in leaves of several legume and non-legume plant species grown at different sites of two areas in semi-arid regions of Syria was determined. In the first area (non-saline soil), the 15N values of a number of fixing and non-fixing reference plants ranged from -2.09 to +9.46, depending on plant species and studied site. 15N in a number of legume species including Acacia cyanopylla (-1.73), Acacia farnesiana (-0.55), Prosopis juliflora (-1.64) and Medicago arborea (+1.6) were close to the atmospheric value pointing to a major contribution of N2 fixing in these species; whereas, those of reference plants were highly positive (between +3.6 and +9.46%). In the actinorhizal tree, Elaeagnus angustifolia, the 15N abundance was far lower (-0.46 to -2.1%) strongly suggesting that the plant obtained large proportional contribution from BNF. In contrast, δ15N values in some other legumes and actinorhizal plants were relatively similar to those of reference plants, suggesting that the contribution of fixed N2 is negligible. On the other hand, δ13C% values in leaves of C3 plants were affected by plant species, ranging from a minimum of -28.67% to a maximum of -23%. However, they were the same within each plant species although they were grown at different sites. Moreover, dual stable isotope analysis in leaves of Prosopis juliflora and other non- legumes grown on a salt affected soil (second area) was also conducted. Results showed that salinity did not affect C assimilation in this woody legume since a higher carbon discrimination was obtained indicating that this plant is a salt tolerant species; whereas, N2-fixation was drastically affected (δ15N= +7.03). (Author)

  15. Irradiance in young stands of Picea abies (L.) Karst. and Pinus sylvestris L. and the possibilities to prevent suckers of broad-leaved trees

    International Nuclear Information System (INIS)

    Incoming shortwave global radiation (Qg) and photosynthetically active radiation (PAR;Qpa) as a fraction of full daylight, relative irradiance (%Q), were measured at the same time in young stands of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). Measurements were made on three levels above ground: 20 cm above ground and 50 and 75% of stand height. Stands of three heights (75, 150 and 300 cm) were studied during two months. The stands were created by arranging young trees cut from natural stands, in nine quadratic spacings: 0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 1.0, 1.4, and 2.0 m. The leaf area index (L) was estimated. Differences in %Q-values for Qpa and Qg in the same species at the same stand height and level of light measurements above ground were significant only in 150 and 300 cm stands. In 75 cm high stands of Scots pine, the %Q was less than 60% at spacings less than 0.2 m and in 75 cm high stands of Norway spruce, the %Q was less than 60% at spacings less than 0.3 m. Only at 0.1 x 0.1-0.3 x 0.3 m, %Q was less than 20% in Norway spruce stands. In 150 cm stands %Q less than 20% was measured at spacings less than 0.7 m in Norway spruce and less than 0.5 in Scots pine. In 300 cm stands of Norway spruce it was measured up to 1.2 and in Scots pine less than 1.1 m. Light extinction coefficients, K and Kg for spruce and pine stands were 0.17-0.40 and 0.16-0.31 respectively. Some practical implications of the study are presented. Lack of light (%Q less than 10%) as a single factor of seriously suppressed growth and development of broad-leaved plants and suckers by competition in young stands of spruce and pine only occur in dense stands 0.3 x 0.3-1.1 x 1.1 m (8000-100000 stems per hectare). Competition by light on a regenerated area generally occurs in the level of 50% of tree height (150-300 cm) and higher due to the rapid growth of broad-leaved trees (sprouts) compared with planted conifers but the light intensity at these levels %Q greater

  16. Ethnobotany, phytochemistry and pharmacological potential ofVitex negundo L. (five-leaved chaste tree):An updated review

    Institute of Scientific and Technical Information of China (English)

    Lubna Abidin; Aftab Ahmad; Shokat Rasool Mir; Mohd Mujeeb; Shah Alam Khan

    2015-01-01

    In the past two decades, a shift in paradigm has been observed in the development of new drugs from the plants for the treatment of diseases. Many scientists are focusing on the evidence based use of medicinal plants to develop pharmacotherapy for various human ailments. An important medicinal plant that has caught the attention of researchers all over the globe is Vitex negundo Linn. This plant is commonly used in various traditional systems of medicine like Ayurveda, Chinese, Siddha and Unani to treat various diseases and has been the subject of extensive research studies lately. Its roots and leaves are widely used in various disorders and illnesses such as skin eczema, ringworm, liver disorders, spleen enlargement, rheumatic pain, gout, abscess, backache etc. Seeds are also used as folklore medicine in bronchitis, eye disorders, female reproductive disorders, cold, dropsy, malarial fever and as demulcent. The current article is an effort to compile an updated review to disseminate knowledge and information among the scientific fraternity covering the progress made in the pharmacology and phytochemistry of this useful medicinal plant. This review on a very important traditional medicine,Vitex negundo L. can serve as a reference to the scientific community for their future research on this plant.

  17. Effects of Mixture Silviculture of Larix kaempferi and Natural-Regenerated Broad-Leaved Trees%日本落叶松与天然萌芽阔叶树人工混交培育效果的分析

    Institute of Scientific and Technical Information of China (English)

    田永霞

    2016-01-01

    通过对日本落叶松与天然萌生阔叶树人工混交林的调查分析,结果表明:日本落叶松与天然萌芽阔叶树人工混交培育降低了培育成本,提高了生态效益,混交林培育28 a 后,林分生长稳定,生产力较高;混交林中的植物种类丰富,数量较多,各层次的物种多样性指数均好于人工营造的日本落叶松与白桦针阔混交林和日本落叶松纯林;日本落叶松与天然萌生阔叶树人工混交林,对恢复森林生态原始林貌有一定促进作用。%Mixture plantation of Larix kaempferi and natural-regenerated broad-leaved trees were investigated.Re-sult shows that silviculture of Larix kaempferi and natural-regenerated broad-leaved trees reduce costs and improve the eco-efficiency,growth of the stand is stable after silviculturing mixed forest for 28 years and the productivity is more higher;plant species of mixed forest is abundant ,the number are larger;all levels of species diversity index are optimal than that of Larix kaempferi ,coniferous and broad-leaved mixed forest and pure forest of Larix kaempferi .Larix kaempferi and natural-regenerated broad-leaved trees have a certain promotion role in restoring original appearance of forest ecology.

  18. A Preliminary Research on Morphological Characteristics of Branches and Leaves Diversity of Ancient Camphor-trees in Jiangxi Province%江西古樟枝叶形态多样性初探

    Institute of Scientific and Technical Information of China (English)

    黄萌; 陈尚钘; 杨光耀; 王宗德; 季春峰

    2014-01-01

    10 morphologic characters of 151 ancient camphor-tree leaves samples in Anyi, Anfu, Ruijin, Wuyuan and Yanshan of Jiangxi province were studied with the numerical taxonomic methods. The Q cluster analysis method wa applied to classify the 151 samples, and the ten characters were analyzed by R cluster as well as principal components analysis method. The result indicated that the ancient camphor-trees can not be divided into different groups based on the present samples and condition because the leaves' shape of ancient camphor-trees has high similarity. However, the shapes of ancient camphor-trees showed two types:the edge of leaves is waved or non-waved. This character has a strong regularity in the ancient camphor-trees leaves. It providea a favorable basis for the future study of system classification and evolution manner of the plants in Lauraceae.%选取10个形态学性状,应用数量分类学方法对江西省安义、安福、瑞金、婺源、铅山5个地区共151株古樟标本进行研究。将数量分类学中的Q聚类应用于5个地区共151份样本的分类,对选取的10个性状进行了R型聚类分析,且对这10个性状进行主成分分析。结果表明:同一地区以及不同地区的古樟之间的差异性不明显,也即古樟在枝叶形态上的相似度很大,依据现有样本和条件暂时无法把古樟分出不同的类群。不过古樟从性状上有两大类型,叶片存在边缘波状和不波的两种情况,此性状在古樟叶片中表现出较强的规律性。本研究为今后利用枝叶形态探讨樟科植物的系统分类和演化方式提供有利的依据。

  19. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  20. 南方3种果树叶片蛋白质和硝态氮动态观察%Dynamic variation of protein and nitrate nitrogen in leaves of three types of southern fruit trees

    Institute of Scientific and Technical Information of China (English)

    朱宇林; 覃秀顺

    2012-01-01

    [目的]研究果树叶片贮藏蛋白质的动态变化规律和氮素积累与降解的调控机理,探讨硝态氮与蛋白质代谢的相关性,为果树的合理施肥和科学管理提供依据.[方法]以南方常绿果树芒果、龙眼和荔枝的秋梢叶片为材料,采用考马斯亮蓝染色法和水杨酸法分别测定其春季期间的总蛋白质含量和硝态氮含量.[结果]芒果、龙眼、荔枝3种南方果树的秋梢叶片中总蛋白质含量均呈前期下降后期上升的“V”字型变化趋势,但平均含量差异较大,龙眼含量最高,为18.03 mg/g,芒果为11.57 mg/g,而荔枝仅有2.53 mg/g;硝态氮含量变化规律不明显,龙眼和荔枝叶片中的硝态氮含量在各阶段都呈现大幅上升的变化趋势,而芒果为先下降后上升.[结论]硝态氮与蛋白质代谢的相关性不显著,叶片中的营养贮藏蛋白质可能是果树早春生长的重要氮源,叶片中蛋白质含量的变动变化可作为果树合理施肥的一个重要指标,但不同树种蛋白质含量水平存在差异.%[Objective]Dynamic variation of protein and mechanism of nitrogen accumulation and degradation in southern fruit tress were studied in the experiment, and correlation analysis was conducted between nitrate nitrogen and protein metabolism to provide references for rational fertilization and scientific management of fruit trees. [Method]Using the leaves of autumn shoots from three evergreen fruit trees: mango, longan and litchi as test material, total protein content and nitrate-N content in leaves during spring and summer were determined by Commassie Brilliant Blue Staining and Salicylic Acid methods, resepctively. [ Result ]The results showed that the total protein content in the leaves of mango, longan and litchi all decreased firstly and increased afterwards with "V"type variation, the average protein content in leaves of three fruit trees followed the trend: longan (18.03 mg/g)>mango( 11.57 mg/g)>litchi (2.53 mg

  1. The effects of foliar fertilization with iron sulfate in chlorotic leaves are limited to the treated area. A study with peach trees (Prunus persica L. Batsch) grown in the field and sugar beet (Beta vulgaris L.) grown in hydroponics.

    Science.gov (United States)

    El-Jendoubi, Hamdi; Vázquez, Saúl; Calatayud, Angeles; Vavpetič, Primož; Vogel-Mikuš, Katarina; Pelicon, Primož; Abadía, Javier; Abadía, Anunciación; Morales, Fermín

    2014-01-01

    Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch) trees grown in the field and sugar beet (Beta vulgaris L. cv. "Orbis") grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush in peach trees and sugar beet plants, respectively. The re-greening of the distal (Fe-treated) and basal (untreated) leaf areas was monitored, and the nutrient and photosynthetic pigment composition of the two areas were also determined. Leaves were also studied using chlorophyll fluorescence imaging, low temperature-scanning electron microscopy microanalysis, scanning transmission ion microscopy-particle induced X-ray emission and Perls Fe staining. The distal, Fe-treated leaf parts of both species showed a significant increase in Fe concentrations (across the whole leaf volume) and marked re-greening, with significant increases in the concentrations of all photosynthetic pigments, as well as decreases in de-epoxidation of xanthophyll cycle carotenoids and increases in photochemical efficiency. In the basal, untreated leaf parts, Fe concentrations increased slightly, but little re-greening occurred. No changes in the concentrations of other nutrients were found. Foliar Fe fertilization was effective in re-greening treated leaf areas both in peach trees and sugar beet plants. Results indicate that the effects of foliar Fe-sulfate fertilization in Fe-deficient, chlorotic leaves were minor outside the leaf surface treated, indicating that Fe mobility within the leaf is a major constraint for full fertilizer effectiveness in crops where Fe-deficiency is established and leaf chlorosis occurs.

  2. The effects of foliar fertilization with iron sulfate in chlorotic leaves are limited to the treated area. A study with peach trees (Prunus persica L. Batsch grown in the field and sugar beet (Beta vulgaris L. grown in hydroponics

    Directory of Open Access Journals (Sweden)

    Hamdi eEl-Jendoubi

    2014-01-01

    Full Text Available Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch trees grown in the field and sugar beet (Beta vulgaris L. cv. ‘Orbis’ grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush in peach trees and sugar beet plants, respectively. The re-greening of the distal (Fe-treated and basal (untreated leaf areas was monitored, and the nutrient and photosynthetic pigment composition of the two areas were also determined. Leaves were also studied using chlorophyll fluorescence imaging, low temperature-scanning electron microscopy microanalysis, scanning transmission ion microscopy-particle induced X-ray emission and Perls Fe staining. The distal, Fe-treated leaf parts of both species showed a significant increase in Fe concentrations (across the whole leaf volume and marked re-greening, with significant increases in the concentrations of all photosynthetic pigments, as well as decreases in de-epoxidation of xanthophyll cycle carotenoids and increases in photochemical efficiency. In the basal, untreated leaf parts, Fe concentrations increased slightly, but little re-greening occurred. No changes in the concentrations of other nutrients were found. Foliar Fe fertilization was effective in re-greening treated leaf areas both in peach trees and sugar beet plants. Results indicate that the effects of foliar Fe-sulfate fertilization in Fe-deficient, chlorotic leaves were minor outside the leaf surface treated, indicating that Fe mobility within the leaf is a major constraint for full fertilizer effectiveness in crops where Fe-deficiency is established and leaf chlorosis occurs.

  3. Inferring the chemical form of 137Cs deposited by the Fukushima Dai-ichi Nuclear Power Plant accident by measuring (137)Cs incorporated into needle leaves and male cones of Japanese cedar trees.

    Science.gov (United States)

    Kanasashi, Tsutomu; Takenaka, Chisato; Sugiura, Yuki

    2016-05-15

    We hypothesized that the water-soluble (ionic) and water-insoluble (stable) radiocesium from the initial fallout of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident was distributed in various proportions in the surrounding areas and that this distribution was reflected in the trees that suffered deposition from the initial fallout. This study attempted to evaluate local variations in the chemical form of (137)Cs derived from the initial fallout of the FDNPP accident and whether its chemical form affected the radiocesium concentration in the tissues currently growing in trees, even after the initial fallout ceased. For these estimations, the ratio between the (137)Cs concentration in Cryptomeria japonica needle leaves in the tree crown, which existed before the FDNPP accident and subsequently directly exposed to the initial fallout ((137)Cs pre-accident N), and the amount of (137)Cs in the initial fallout itself ((137)Cs fallout) was determined ((137)Cs pre-accident N/(137)Cs fallout) at 66 sites. In addition, the (137)Cs ratios between the male cones produced in 2012 ((137)Cs male cone) and needle leaves that had elongated in the spring of 2011 ((137)Cs 2011N) was determined at 82 sites ((137)Cs male cone/(137) Cs 2011N). Most of the sites with lower (137)Cs pre-accident N /(137)Cs fallout ratios were distributed in eastern Fukushima, relatively close to the Pacific Ocean coastline. Lower (137)Cs pre-accident N/(137)Cs fallout and higher (137)Cs malecone/(137)Cs 2011N were found to be associated with higher proportions of (137)Cs in ionic forms. These observations are consistent with the hypothesis, and likely reflect regional variations in the chemical form of the deposited radiocesium. PMID:26990074

  4. Antioxidant properties of various solvent extracts of total phenolic constituents from three different agroclimatic origins of drumstick tree (Moringa oleifera Lam.) leaves.

    Science.gov (United States)

    Siddhuraju, Perumal; Becker, Klaus

    2003-04-01

    Water, aqueous methanol, and aqueous ethanol extracts of freeze-dried leaves of Moringa oleifera Lam. from different agroclimatic regions were examined for radical scavenging capacities and antioxidant activities. All leaf extracts were capable of scavenging peroxyl and superoxyl radicals. Similar scavenging activities for different solvent extracts of each collection were found for the stable 1,1-diphenyl 2-picrylhydrazyl (DPPH(*)) radical. Among the three different moringa samples, both methanol and ethanol extracts of Indian origins showed the highest antioxidant activities, 65.1 and 66.8%, respectively, in the beta-carotene-linoleic acid system. Nonetheless, increasing concentration of all the extracts had significantly (P flavonoid groups such as quercetin and kaempferol. On the basis of the results obtained, moringa leaves are found to be a potential source of natural antioxidants due to their marked antioxidant activity. This is the first report on the antioxidant properties of the extracts from freeze-dried moringa leaves. Overall, both methanol (80%) and ethanol (70%) were found to be the best solvents for the extraction of antioxidant compounds from moringa leaves. PMID:12670148

  5. 北京市常见落叶树种叶片滞纳空气颗粒物功能%Atmospheric Particle Retaining Function of Common Deciduous Tree Species Leaves in Beijing

    Institute of Scientific and Technical Information of China (English)

    王兵; 王晓燕; 牛香; 张维康; 汪金松

    2015-01-01

    In order to explore the atmospheric particle-retaining function of common deciduous tree species leaves in Beijing, six typical tree species (Populus, Robinia pseudoacacia, Koelreuteria paniculata, Salix babylonica, Acer truncatum, Ginkgo biloba) were chosen to measure retaining amount of unit leaf area of air total suspended particles (TSP), coarse particles and fine particulate with aerosol generator (QRJZFSQ-I). The results showed that ① All six tree species leaves had a certain level of retaining ability to different sizes of atmospheric particles, and different species exhibited some differences. For different sizes of atmospheric particle, retaining amounts of unit leaf area were higher in Koelreuteria paniculata and Robinia pseudoacacia than those of other four species, and the amount of Populus was the lowest among all tree species; ②The retaining amount of unit leaf area for different tree species was not entirely increased with sampling time. The retaining amounts of TSP and coarse particles for all tree species on the eighth day after rain were significantly higher than those on the fifth day after rain, however, the retaining amount of fine particles was not significantly different under different sampling times. In order to select deciduous tree species for ecological management of air pollution in Beijing, Koelreuteria paniculata should be considered as the priority, followed by Robinia pseudoacacia, compared with Ginkgo biloba, Salix babylonica, Acer truncatum and Populus.%为了探求北京市常见落叶乔木树种滞纳空气颗粒物的功能,选取了6种典型落叶乔木树种(杨树、刺槐、栾树、垂柳、元宝枫、银杏),利用空气气溶胶再发生器(QRJZFSQ-I)测定了不同树种单位面积叶片对空气总悬浮颗粒物(TSP)、粗颗粒物和细颗粒物的滞纳量。结果表明:①6个树种的叶片对不同粒径空气颗粒物均能起到一定的滞纳作用,且不同树种滞纳量表现出较大

  6. 叶山林场次生阔叶林乔木树种多样性及种间关联分析%Analysis of tree species diversity and interspecific association of tree layer in secondary broad-leaved forest in Yeshan forest-farm

    Institute of Scientific and Technical Information of China (English)

    郝耀锋; 樊丙玉; 吴开华; 黄庆丰

    2012-01-01

    通过铜陵叶山林场次生落叶阔叶林样地调查,对乔木层物种丰富度指数、植物多样性指数、Pielou均匀度指数、生态优势度指数、重要值和种间关联进行分析.结果表明,在12块样地中共有乔木树种19种,平均植物多样性指数、均匀度指数和生态优势度指数分别为1.25、0.70和0.37.优势树种麻栎重要值为105.3,伴生树种化香、枫香和国槐重要值分别为65.1、36.3和18.6.该森林类型为麻栎落叶阔叶混交林.19个树种之间共存在171对相关,但正关联树种对少于负关联树种对,正负关联比小于1,说明该群落类型还处于演替阶段,即由落叶阔叶林向常绿与落叶阔叶混交林过渡阶段.%Based on the investigation of plots, the indexes of species richness, plant diversity, Pielou evenness and ecological dominance, important value and interspecific association of tree layer in secondary broad-leaved forest were calculated and analyzed in Yeshan forest-farm of Tongling county. The results showed that there are 19 tree species in the 12 plots. Mean indexes of plant diversity, evenness and ecological dominance are 1.25, 0.70 and 037, respectively. The important value of dominant tree, Quercus acutissima, is 105.3, and the companion tree species, Platycarya strobilacea, Liquidambar formosana and Sophorajaponica, are 65.1, 36.3 and 18.6, respectively. This forest type is Quercus acutissima deciduous broadleaved mixed forest. One hundred and seventy-one tree species coexist correlation among 19 tree species, but the pairs of the positive associated tree species are less than the negative ones. The ratio between the positive and negative association is less than 1, which mean that this community type is still in successive stage, namely the transition stage from the deciduous broadleaved forest to the evergreen and deciduous broadleaved mixed forest.

  7. A rabies vaccine adjuvanted with saponins from leaves of the soap tree (Quillaja brasiliensis) induces specific immune responses and protects against lethal challenge.

    Science.gov (United States)

    Yendo, Anna Carolina A; de Costa, Fernanda; Cibulski, Samuel P; Teixeira, Thais F; Colling, Luana C; Mastrogiovanni, Mauricio; Soulé, Silvia; Roehe, Paulo M; Gosmann, Grace; Ferreira, Fernando A; Fett-Neto, Arthur G

    2016-04-29

    Quillaja brasiliensis (Quillajaceae) is a saponin producing species native from southern Brazil and Uruguay. Its saponins are remarkably similar to those of Q. saponaria, which provides most of the saponins used as immunoadjuvants in vaccines. The immunostimulating capacities of aqueous extract (AE) and purified saponin fraction (QB-90) obtained from leaves of Q. brasiliensis were favorably comparable to those of a commercial saponin-based adjuvant preparation (Quil-A) in experimental vaccines against bovine herpesvirus type 1 and 5, poliovirus and bovine viral diarrhea virus in mice model. Herein, the immunogenicity and protection efficacy of rabies vaccines adjuvanted with Q. brasiliensis AE and its saponin fractions were compared with vaccines adjuvanted with either commercial Quil-A or Alum. Mice were vaccinated with one or two doses (on days 0 and 14) of one of the different vaccines and serum levels of total IgG, IgG1 and IgG2a were quantified over time. A challenge experiment with a lethal dose of rabies virus was carried out with the formulations. Viral RNA detection in the brain of mice was performed by qPCR, and RNA copy-numbers were quantified using a standard curve of in vitro transcribed RNA. All Q. brasiliensis saponin-adjuvanted vaccines significantly enhanced levels of specific IgG isotypes when compared with the no adjuvant group (P ≤ 0.05). Overall, one or two doses of saponin-based vaccine were efficient to protect against the lethal rabies exposure. Both AE and saponin fractions from Q. brasiliensis leaves proved potent immunological adjuvants in vaccines against a lethal challenge with a major livestock pathogen, hence confirming their value as competitive or complementary sustainable alternatives to saponins of Q. saponaria. PMID:27032516

  8. Natural abundances of 15N and 13C in leaves of some N2-fixing and non-N2-fixing trees and shrubs in Syria.

    Science.gov (United States)

    Kurdali, F; Al-Shamma'a, M

    2009-09-01

    A survey study was conducted on man-made plantations located at two different areas in the arid region of Syria to determine the variations in natural abundances of the (15)N and (13)C isotopes in leaves of several woody legume and non-legume species, and to better understand the consequence of such variations on nitrogen fixation and carbon assimilation. In the first study area (non-saline soil), the delta(15)N values in four legume species (Acacia cyanophylla,-1.73 per thousand Acacia farnesiana,-0.55 per thousand Prosopis juliflora,-1.64 per thousand; and Medicago arborea,+1.6 \\textperthousand) and one actinorhizal plant (Elaeagnus angustifolia,-0.46 to-2.1 per thousand) were found to be close to that of the atmospheric value pointing to a major contribution of N(2) fixing in these species; whereas, delta(15)N values of the non-fixing plant species were highly positive. delta(13)C per thousand; in leaves of the C3 plants were found to be affected by plant species, ranging from a minimum of-28.67 per thousand; to a maximum of-23 per thousand. However, they were relatively similar within each plant species although they were grown at different sites. In the second study area (salt affected soil), a higher carbon discrimination value (Delta(13)C per thousand) was exhibited by P. juliflora, indicating that the latter is a salt tolerant species; however, its delta(15)N was highly positive (+7.03 per thousand) suggesting a negligible contribution of the fixed N(2). Hence, it was concluded that the enhancement of N(2) fixation might be achieved by selection of salt-tolerant Rhizobium strains. PMID:20183233

  9. Natural abundances of 15N and 13C in leaves of some N2- fixing and non N2- fixing trees and shrubs in Syria

    International Nuclear Information System (INIS)

    A survey study was conducted on man-made plantations located at two different areas in the arid region of Syria to determine the variations in natural abundances of the 12N and 13C isotopes in leaves of several woody legume and non-legume species, and to better understand the consequence of such variations on nitrogen fixation and carbon assimilation. In the first study area (non-saline soil), the δ15N values in four legume species (Acacia cyanopylla, -1.73 %; Acacia farnesiana, -0.55%; Prosopis juliflora, -1.64%, and Medicago arborea, +1.6%) and one actinorhizal plant (Elaeagnus angustifolia, -0.46 to -2.1%) were found to be close to that of the atmospheric value pointing to a major contribution of N2 fixing in these species; whereas, δ15N values of the non-fixing plant species were highly positive.δ13C% in leaves of the C3 plants were found to be affected by plant species, ranging from a minimum of -28.67% to a maximum of -23%. However, they were relatively similar within each plant species although they were grown at different sites. In the second study area (salt affected soil) a higher carbon discrimination value (Δ3C%) was exhibited by Prosopis juliflora indicating that the latter is a salt tolerant species; however, its δ 15N was highly positive (+7.03%) suggesting a negligible contribution of the fixed N2. Hence, it was concluded that the enhancement of N2 fixation might be achieved by selection of salt-tolerant rhizobium strains. (author)

  10. Atividade de extrato aquoso de folhas de nim (Azadirachta indica sobre Spodoptera frugiperda Activity of neem tree (Azadirachta indica leaves aqueous extract on Spodoptera frugiperda

    Directory of Open Access Journals (Sweden)

    Hélio Teixeira Prates

    2003-03-01

    Full Text Available A lagarta-do-cartucho do milho (Spodoptera frugiperda (J. E. Smith tem sido controlada com inseticidas sintéticos. Uma das caracteristicas do nim (Azadirachta indica A. Juss é sua atividade inseticida contra pragas, como sucedâneo aos sintéticos. O objetivo deste trabalho foi avaliar a atividade inseticida do extrato aquoso das folhas do nim sobre a lagarta-do-cartucho do milho, em laboratório. Bioensaios com diferentes concentrações de extrato em dieta artificial, tendo o inseticida chlorpyrifos como testemunha, revelaram, 15 dias após infestação com larvas, eficiência equivalente entre as concen- trações 3,60 a 10,00 mg mL-1. A análise de Probit mostrou CL50 = 2,67 mg mL-1; o extrato aquoso das folhas de nim apresenta, portanto, efeito inseticida sobre a lagarta-do-cartucho do milho.The fall armyworm (Spodoptera frugiperda (J. E. Smith has been controlled with synthetic insecticides bringing risk to the environment. Neem (Azadirachta indica A. Juss is reported to be a natural alternative to synthetic insecticides against many insect species. The objective of this work was to evaluate the activity of neem leaves aqueous extract on fall armyworm, in laboratory. Bioassays carried out using artificial feed with various extract concentrations, and chlorpyrifos as control, indicated, 15 days after larvae infestation, similar efficiency in concentrations from 3.60 to 10.00 mg mL-1. Probit analysis showed LC50 = 2.67 mg mL-1. Hence, aqueous extract from neem leaves are active against fall armyworm.

  11. Effects of micro-topographies on stand structure and tree species diversity in an old-growth evergreen broad-leaved forest, southwestern Japan

    Directory of Open Access Journals (Sweden)

    Tran Van Do

    2015-07-01

    Full Text Available Stand structure and species diversity were studied in correspondence with micro-topographies in an old-growth forest in southwestern Japan. The study was conducted in a 200×200m2 permanent plot, which were divided into 400 subplots using grids of 10m×10m. Subplots were categorized to four micro-topographies as crest slope (CS, head hollow (HH, upper slope (US and lower slope (LS, basing on slope of forest floor and plot position, and to two elevational zones as below 450 m and above 450 m. Tree censuses for all individuals with diameter at breast height (DBH ⩾ 5 cm were conducted in 2009 and 2013. The results indicated that CS had subplot means of living stems, dead stems, DBH, basal area (G, and basal area increment (▵G significantly higher than that in LS. While, means of recruited stems and Shannon diversity index were significantly lower. Comparing between below and above 450 m elevational zones indicated the significantly higher parameters of stand structure and species diversity in above 450 m elevational zone. The differences of edaphic conditions led to difference of density of living stems, species density, DBH, G, and ▵G among micro-topographies. Therefore, crest slope, upper slope, and higher elevational zones should be encouraged for the purposes of carbon accumulation and storage. While, the lower elevational zones should be used for the purposes of species diversity conservation.

  12. Taking Leave?

    CERN Document Server

    2000-01-01

    Planning a holiday? Then if you're a member of the personnel, you'll need to use the Laboratory's new leave system that will be put in place on 1 October. Leave allocations don't change - you are entitled to just as much holiday as before - but instead of being credited annually, your leave will be credited on a monthly basis, and this information will be communicated on your salary slip. The reason for the change is that with the various new leave schemes such as Recruitment by Saved Leave (RSL) and the Progressive Retirement Programme (PRP), a streamlined procedure was required for dealing with all kinds of leave. In the new system, each member of the personnel will have leave accounts to which leave will be credited monthly from the payroll and debited each time an absence is registered in the CERN Electronic Document Handling system (EDH). Leave balances will appear on monthly pay slips, and full details of leave transactions and balances will be available through EDH at all times. As the leave will be c...

  13. Magnetic Response of Street Tree Leaves to Particulate Pollution in Shanghai%城市道路绿化带不同植物叶片附尘对大气污染的磁学响应

    Institute of Scientific and Technical Information of China (English)

    隆茜; 周菊珍; 孟颉; 达良俊

    2012-01-01

    To reveal the magnetic response to atmospheric particulate pollution in tree leaves along urban streets,twenty-four evergreen tree leaves were collected from green belt along Jinshajiang road,Shanghai,which were subjected to magnetic and heavy metals(Zn,Cu,Pb) analyses.The result revealed that in all leaf samples χ,SIRM varied in ranges of(4-59)×10-8 m3·kg-1 and(496-6 114)×10-6 Am2·kg-1,respectively,S-300mT varied from 89% to 98% and χARM/χ4,χARM/SIRM30×10-5 mA-1 was found.The magnetic parameters showed that ferromagnetic/ferrimagnetic particles were the main magnetic carriers in dust-loaded tree leaves,and magnetic grains were predominantly pseudo-single domain(PSD) and multidomain(MD) in size.The significant positive correlation between heavy metals(Zn,Cu,Pb) contents and χ,SIRM,χARM,suggested that magnetic parameters like SIRM could be used as a proxy for heavy metal contents.We recommend that Magnolia grandiflora,widely distributed in Shanghai,can be used for particulate pollution monitoring.%对上海市金沙江路两侧绿化带内24个常绿植物叶片样品进行了磁性与重金属测试,以探讨城市道路绿化带不同植物叶片附尘对大气污染的磁学响应.结果表明,χ、SIRM值分别在(4~59)×10-8m3.kg-1和(496~6 114)×10-6Am2.kg-1之间变化,S-300 mT在89%~98%之间变动.所有植物样品中χARM/χ〈4,χARM/SIRM〈30×10-5mA-1.磁性参数表明,植物叶片附尘以亚铁磁性矿物为主,磁性矿物颗粒以假单畴(PSD)-多畴(MD)为主.重金属元素Zn、Cu、Pb含量与反映亚铁磁性矿物含量的χ、SIRM、χARM呈显著正相关,可以将磁性参数SIRM作为叶片重金属元素的替代指标.推荐在上海地区广泛种植的广玉兰作为道路植物污染的指示植物。

  14. Different Methods of Extracting Invertase from the Leaves of Hevea brasiliensis(Para Rubber Tree)%橡胶树叶片转化酶提取方法的比较

    Institute of Scientific and Technical Information of China (English)

    蓝基贤; 何慧; 戚继艳; 唐朝荣

    2012-01-01

    比较液氮研磨样品与蛋白抽提液研磨样品对6种提取橡胶树叶片转化酶方法的效果.结果表明:液氮研磨法对转化酶活性影响很大,特别是中性/碱性转化酶和细胞壁结合的酸性转化酶已基本失活,而可溶性酸性转化酶活性丧失也比较严重.利用蛋白抽提液研磨样品,用Hepes-NaOH法提取的可溶性转化酶的酶活性最高,达472.44 μmol (glucose)/[g (FW)·h];虽然磷酸-柠檬酸法获得的粗酶液的蛋白含量较低,但其酶活性高达441.61 μmol( glucose)/[g( FW)·h];Tris-HCl法提取的细胞壁结合酸性转化酶的酶活性最高,达35.83 μmol( glucose)/[g(FW)·h].从转化酶的比活力看,磷酸-柠檬酸法最佳,所提取的叮溶性转化酶比活力约为Hepes-NaOH法的4倍.本研究结果为进一步完善橡胶树叶片转化酶的提取方法提供重要的指导意义.%Six methods were investigated in extracting invertase from the leaves of rubber tree(Hevea brasiliensis Muell. Arg)by two ways of grinding leaves: liquid nitrogen and extraction buffer. Grinding leaves in liquid nitrogen seriously destroyed the activities of invertases, especially those of neutral/alkaline invertase and cell wall-bound invertase which were totally inactivated. In comparison, the way of grinding leaves in extraction buffers was suitable for extracting various types of invertase. After the leaves were ground in extraction buffers, the activity of crude soluble invertase extracted by Hepes -NaOH method revealed to be the highest, being 472.44 u.mol (glucose )/[g (FW) o h]. Despite low protein yields obtained by phosphate -citrate method, the resulting invertase activity was as high as 441.61 μmol (glucose)/[g(FW) ·h]. Regarding the cell wall-bound invertase, Tris-HCl method was the most suitable, resulting in invertase activity of 35.83 μmol (glucose )/[g (FW)·h]. With regard to specific enzymatic activity, the phosphate-citrate method was the most appropriate, with specific

  15. Comparison of heavy metal contents in their leaves by 17 road afforestation trees%17种道路绿化树木叶片重金属镉和铬含量的比较研究

    Institute of Scientific and Technical Information of China (English)

    刘冰

    2014-01-01

    The urban road green trees could absorb heavy metal pollutants in the atmosphere.The heavy metals Cd and Cr contents in leaves of 17 virescence trees in Xinxiang City are analysed.The results indicate that the same road afforestation trees show different heavy metal contents in their leaves,polluted area > clear area, Autumn > Spring, Cd > Cr; simultaneously different species show quite different contents to the same heavy metal element,the content of Cd is in the order of Populus alba >Acer mono >Populus tomentosa > Ligustrum quihoui Carr > Ligustrum lucidum > Prunus ceraifera > Euonymus j aponicus > Koelreuteria paniculata > P latanus acerifolia > Ailanthus altissima > Broussonetia papyrifera > Fraxinus chinensis > Sophora j aponica > Photinia frasery > Pittosporum tobira >Yucca gloriosa >Buxus microphylla;the content of Cr is in the order of Acer mono > Populus tomentosa >Populus alba > Prunus ceraifera > Buxus microphylla > Photinia frasery > P latanus acerifolia >Sophora j aponica >Yucca gloriosa >Broussonetia papyrifera >Ligustrum quihoui Carr >Pittosporum tobira >Koelreuteria paniculata >Ligustrum lucidum >Ailanthus altissima >Fraxinus chinensis >Buxus megistophylla .The afforest trees are classified three at the basis of the content of Cd and Cr,the first category includes Populus tomentosa and Acer mono ;Prunus ceraiferai ,P latanus acerifolia ,Populus alba ,Buxus microphylla and Photinia frasery belong to the second category;the third category includes Fraxinus chinensis ,Sophora j aponica ,Broussonetia papyrifera ,Ailanthus altissima ,Koelreuteria paniculata , Pittosporum tobira ,Yucca gloriosa , Euonymus j aponicus , Ligustrum lucidum and Ligustrum quihoui Carr . Heavy metal contents in road green trees leaves show markedly difference depending on function areas,seasons,heavy metal kinds and tree species.%对新乡市17种道路绿化树木叶片重金属镉和铬的含量进行了分析,结果表明,同种道路绿化树木叶片的重金属含

  16. Foliar concentration of heavy metals in the leaves of trees in mining area as a mechanism for phytoremediation%矿区常见乔木叶片重金属特征及其修复应用

    Institute of Scientific and Technical Information of China (English)

    邱媛; 何际泽; 杨汉彬; 张良军; 黄良美; 温远光; 杨梅; 张新英

    2013-01-01

    Absrtact:Mining has a range of deleterious effects on the environment, including increasing the concentration of heavy metals in soils. Natural revegetation may contribute to phytoremediation by removing heavy metals. Therefore it’s important to determine which trees are most effective at phytoremediation. The vegetation and the topsoil of the mining area in Dachang Mine of Hechi city, Guangxi Province, China, were investigated, to determine which trees are more suitable for phytoremediation for the heavy metal pollution. The total content of heavy metals (Mn, Zn, Cu, As, Cd, Sn, Sb and Pb) in the leaves of eight tree species and in the topsoil were measured in the three sites in the mining area. The trees were:Pyrus pyrifolia (burm.f.) nakai, Castanea mollissima, Hovenia acerba, Citrus maxima, Ginkgo biloba, Cinnamomum camphora, Diospyros kaki, Eriobotrya japonica. The concentrations of heavy metals in leaves were detected by ICP-MS and ICP-AES, and in soil by ICP-AES. The concentrations of heavy metals were over 5-1200 times background values for soils in the Guangxi Province; with Cd more than 1200 times background values. There were no significant differences in foliar heavy metal contents among the three sampling sites except for Mn;and there were no significant differences among tree species in foliar heavy metal concentrations, either. Concentrations per leaf were converted to values per tree using an equation for tree leaf biomass. H. acerba and C. camphora accumulated more different heavy metals than the others overall. For example a single H. acerba tree can absorb 21.25 g Mn, 3.003g Zn, 0.20 g Cu, 0.28 g As, 0.066 g Cd, 0.014 g Sn, 0.17 g Sb and 1.23 g Pb, while a C. camphora tree can absorb 1.55 g Mn, 0.79g Zn, 0.17 g Cu, 0.12 g As, 0.011 g Cd, 0.017 g Sn, 0.14 g Sb and 0.40 g Pb. The values for the two fruit trees, P. pyrifolia and C. mollissim were also high, for P. pyrifolia can uptake 2.90 g Mn, 3.32 g Zn 0.57 g Cu, 0.11 g As, 0.043 g Cd, 0.014 g

  17. Tree sets

    OpenAIRE

    Diestel, Reinhard

    2015-01-01

    We study an abstract notion of tree structure which generalizes tree-decompositions of graphs and matroids. Unlike tree-decompositions, which are too closely linked to graph-theoretical trees, these `tree sets' can provide a suitable formalization of tree structure also for infinite graphs, matroids, or set partitions, as well as for other discrete structures, such as order trees. In this first of two papers we introduce tree sets, establish their relation to graph and order trees, and show h...

  18. Natural isotopes abundance of sup 1 sup 5 N and sup 1 sup 3 C in leaves of some N sub 2 -fixing and non N sub 2 -fixing trees and shrubs in Syria

    International Nuclear Information System (INIS)

    Varability in the natural abundance isotopes of sup 1 sup 5 N and sup 1 sup 3 C in leaves of several legume and non-legume plant species grown at different sites of two areas in semi-arid regions of Syria was determined. In the first area (non-saline soil), the sup 1 sup 5 N values of a number of fixing and non-fixing reference plants ranged from -2.09 to +9.46, depending on plant species and studied site. sup 1 sup 5 N in a number of legume species including Acacia cyanopylla (-1.73), Acacia farnesiana (-0.55), Prosopis juliflora (-1.64) and Medicago arborea (+1.6) were close to the atmospheric value pointing to a major contribution of N sub 2 fixing in these species; whereas, those of reference plants were highly positive (between +3.6 and +9.46%). In the actinorhizal tree, Elaeagnus angustifolia, the sup 1 sup 5 N abundance was far lower (-0.46 to -2.1%) strongly suggesting that the plant obtained large proportional contribution from BNF. In contrast, delta sup 1 sup 5 N values in some other legumes and actinorhizal plants were relatively similar to those of reference plants, suggesting that the contribution of fixed N sub 2 is negligible. On the other hand, delta sup 1 sup 3 C% values in leaves of C3 plants were affected by plant species, ranging from a minimum of -28.67% to a maximum of -23%. However, they were the same within each plant species although they were grown at different sites. Moreover, dual stable isotope analysis in leaves of Prosopis juliflora and other non- legumes grown on a salt affected soil (second area) was also conducted. Results showed that salinity did not affect C assimilation in this woody legume since a higher carbon discrimination was obtained indicating that this plant is a salt tolerant species; whereas, N2-fixation was drastically affected (delta sup 1 sup 5 N= +7.03). (Author)

  19. Hyperspectral Characteristics of Subtropical Evergreen Broad-Leaved Trees at Different Levels of Simulated Shade%亚热带常绿阔叶树种对模拟遮荫胁迫的高光谱响应

    Institute of Scientific and Technical Information of China (English)

    徐建辉; 江洪

    2014-01-01

    利用 ASD 地物光谱仪,测定不同梯度遮荫胁迫条件下4种亚热带常绿阔叶树种的光谱反射率,应用微分技术处理其反射光谱,并结合 SPAD-502测定的叶绿素相对含量进行分析,研究其在遮荫胁迫情况下的高光谱特征。结果表明:4种树种都具有一定的耐荫性,遮荫处理会影响树种的叶绿素含量,透光率85%的遮荫处理下的叶绿素含量最大;透光率85%的遮荫处理下红边位置发生“红移”现象,但过高的遮荫处理会抑制其生长,出现红边位置“蓝移”现象。不同遮荫梯度下,红边位置对应窄波段范围内的平均一阶微分光谱与叶绿素含量间的相关性较高,R 2大于0.61,相关性显著。本研究通过分析4种亚热带常绿阔叶树种在不同遮荫梯度下的光谱变化特征,以及红边位置对应窄波段范围内平均一阶微分光谱与叶绿素含量的相关性,证明了遮荫影响4种树种的生长,红边位置的一阶微分光谱能有效地监测遮荫对树种的影响,为在大气气溶胶阳伞效应条件下森林植物的生长遥感监测提供了理论依据。%Using the ASD spectrometer to determine the spectral reflectance of four kinds of subtropical evergreen broad-leaved species in different gradient shading stress conditions,the differential technology to process their reflectance spectra,and combining the relative chlorophyll content of SPAD-502 for analysis,this paper studies spectral variation characteristics of four tree species in the shading stress conditions.The results showed that:four kinds of trees have a certain shade tolerance,tree shading will affect chlorophyll content,light transmission rate of 85% shade treatments has maximum chlorophyll content;the red edge position expressed as “red shift”in light transmission rate of 85% shade treatments condition,but excessive shading treatment will inhibit their growth,red edge position expressed as

  20. Misunderstanding sap ascent in trees

    OpenAIRE

    Cochard, Hervé; Delzon, Sylvain

    2013-01-01

    Trees transport water from their roots to their leaves thanks to an efficient but vulnerable vascular system. Assessing the vulnerability to drought of the xylem and its ability to recover from failure are not an easy task but recent findings demonstrate that, contrary to what is commonly believed, hydraulic failure and embolism repair are not routine in trees.

  1. Gene tree correction for reconciliation and species tree inference

    Directory of Open Access Journals (Sweden)

    Swenson Krister M

    2012-11-01

    Full Text Available Abstract Background Reconciliation is the commonly used method for inferring the evolutionary scenario for a gene family. It consists in “embedding” inferred gene trees into a known species tree, revealing the evolution of the gene family by duplications and losses. When a species tree is not known, a natural algorithmic problem is to infer a species tree from a set of gene trees, such that the corresponding reconciliation minimizes the number of duplications and/or losses. The main drawback of reconciliation is that the inferred evolutionary scenario is strongly dependent on the considered gene trees, as few misplaced leaves may lead to a completely different history, with significantly more duplications and losses. Results In this paper, we take advantage of certain gene trees’ properties in order to preprocess them for reconciliation or species tree inference. We flag certain duplication vertices of a gene tree, the “non-apparent duplication” (NAD vertices, as resulting from the misplacement of leaves. In the case of species tree inference, we develop a polynomial-time heuristic for removing the minimum number of species leading to a set of gene trees that exhibit no NAD vertices with respect to at least one species tree. In the case of reconciliation, we consider the optimization problem of removing the minimum number of leaves or species leading to a tree without any NAD vertex. We develop a polynomial-time algorithm that is exact for two special classes of gene trees, and show a good performance on simulated data sets in the general case.

  2. The nutritional levels in leaves and fruits of fig trees as a function of pruning time and irrigation / Teores nutricionais em folhas e frutos de figueira, submetida a épocas de poda e irrigação

    Directory of Open Access Journals (Sweden)

    Marco Antonio Tecchio

    2009-07-01

    Full Text Available The present study aimed to evaluating the nutritional content in leaves and fruits of the fg tree ‘Roxo de Valinhos’, pruned at different periods corresponding to the months of July, August, September and October in the years of 2004 and 2005, with and without the use of irrigation, in the county of Botucatu, São Paulo State, Brazil. To achieve this objective, the adopted experimental design was in blocks with subdivided plots and 5 replications, in which plots corresponded to treatments with and without irrigation and subplots included prunings done in the above-mentioned four months. The levels of N, P, K, Ca, Mg, S, B, Cu, Mn and Zn in leaves and fruits were evaluated in the two crop cycles. The results indicated no signifcant differences among macro and micronutrient levels in the leaves subjected to treatments with and without irrigation in the cycle 2004/05, except for cupper which showed higher level with the treatment including irrigation (6 mg kg-1. In the fruits, there was no difference, except for Zn, which also showed the highest levels (28 mg kg-1 with irrigation. In the crop cycle 2005/06, there were differences for N (40 g kg-1 and K (20 g kg-1 in the leaves, where the highest levels were observed with the treatment including irrigation. In the fruits, N had signifcant difference and its highest level was observed without irrigation (21 g kg-1. In relation to the pruning periods, signifcant differences were observed for Ca, Fe and Zn content in the leaves and Ca, K, Mg, S and Zn content in the fruits in the crop cycle 2004/05. In the cycle 2005/06, there were not differences among the levels of the evaluated nutrients in the leaves, and in the fruits there was difference for N, Ca and Cu.O trabalho teve como objetivo avaliar os teores nutricionais foliares e nos frutos de fgueira ‘Roxo de Valinhos’, podada em diferentes épocas, correspondentes aos meses de julho, agosto, setembro e outubro dos anos de 2004 e 2005, com e

  3. Impact of African weaver ant nests [Oecophylla longinoda Latreille (Hymenoptera: Formicidae)] on Mango [Mangifera indica L. (Sapindales: Anacardiaceae)] leaves

    OpenAIRE

    Anato, Florence; Sinzogan, Antonio; Adandonon, Appolinaire; Hounlidji, Xavier; Offenberg, Joachim; Kossou, Dansou; Vayssières, Jean-Francois

    2015-01-01

    Oecophylla ants are appreciated for their control of pests in plantation crops. However, the ants´ nest building may have negative impacts on trees. In this study we tested the effect of ant densities and nest building on the leaf performance of mango trees. Trees were divided into three groups: trees without ants, trees with low and trees with high ant densities. Subsequently, the total number of leaves, the proportion of leaves used for nest construction, and tree growth was compared betwee...

  4. The Shapley Value of Phylogenetic Trees

    CERN Document Server

    Haake, Claus-Jochen; Su, Francis Edward

    2007-01-01

    Every weighted tree corresponds naturally to a cooperative game that we call a "tree game"; it assigns to each subset of leaves the sum of the weights of the minimal subtree spanned by those leaves. In the context of phylogenetic trees, the leaves are species and this assignment captures the diversity present in the coalition of species considered. We consider the Shapley value of tree games and suggest a biological interpretation. We determine the linear transformation M that shows the dependence of the Shapley value on the edge weights of the tree, and we also compute a null space basis of M. Both depend on the "split counts" of the tree. Finally, we characterize the Shapley value on tree games by four axioms, a counterpart to Shapley's original theorem on the larger class of cooperative games.

  5. Leaving Iraq?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It has been three years since the war in Iraq began, but the situation in the country, especially the security, has not improved much. Meanwhile, the world is wondering when U.S. troops will leave, and the American public appears to be getting impatient with the seemingly endless casualty reports. Some groups have held

  6. Nutrient cycling in mango trees

    Directory of Open Access Journals (Sweden)

    Cinara Xavier de Almeida

    2014-02-01

    Full Text Available Estimates of nutrient amounts both shedding and demanding replacement in the maintenance of productivity of fruit trees require studies on element dynamics within the many ecosystem components generally made up of nutrient cycling. Thus, it was the objective of this study to evaluate the nutrient biochemical cycling in a mango tree (Mangifera indica L. orchard, Palmer variety. Macronutrients [nitrogen (N, phosphorus (P, potassium (K, calcium (Ca, magnesium (Mg, and sulfur (S] had their contents evaluated in leaves at different stages: new, mature, senescent, and litter. First exploratory analysis was performed for main components which preserve the multivariate structure shown by the data. It was possible to observe the association of new leaves with N, P, K, Mg, and S; senescent leaves and the leaves from the litter were associated to Ca, while mature leaves, to K. As a complement, taking the independent variables into consideration, Tukey test (p?0.01 showed that the averages of N, P, and Ca differ between the new and the mature leaves; average of Mg in new leaves differs from the others, and S does not differ along the stages. Also observed was the re-translocation of 41%, 63% and 57% of N, P, and K, respectively, when comparison was made among the contents of the elements in mature leaves as well as in litter, which indicates that the biochemical cycling is important for the mango tree cultivation.

  7. Determination of flavonoids in tree leaves by HPLC with fluorescence detector%高效液相色谱法-荧光检测器测定树叶中的黄酮

    Institute of Scientific and Technical Information of China (English)

    吴波; 杜胜蓝; 刘文杰

    2009-01-01

    建立了高效液相色谱法-荧光检测器测定树叶中的黄酮(槲皮素,桑色素和山奈酚)含量的方法.采用Polaris C18色谱柱(2.0m×100mm,3μm),柱温60℃;流动相,A相为0.1mol/L HAc,B相为乙腈,流速0.3mL/min;梯度淋洗,柱后衍生;激发波长438nm,发射波长483nm.槲皮素、桑色素和山奈酚的线性范围及相关系数分别为,1.720~13.76mg/L,r=1.000;0.222~0.888mg/L,r=0.9997; 0.965~7.720mg/L,r=0.9991.平均回收率在90.0%~101.5%之间.该方法简便、准确,可用于植物中槲皮素,桑色素和山奈酚含量的测定.%A method of high performance liquid chromatography (HPLC) with fluorescence detector was established for quantitative determination of flavonoids (quercetin, morin hydrate and kaempferol) in tree leaves. The flavonoids were separated on a Polaris C18 column (2.0m×100mm,3μm) at 60℃. Mobile phase A was 0.1 mol/L HAc and mobile phase B was acetonitrile, with the flow rate of 0.3 mL/min. The gradient elution and post-column derivatization were employed. The excitation wavelength and emission wavelength were 438nm and 483nm, respectively. The linear ranges were 1.720~13.76mg/L (r=1.0000) for quercetin, 0.222~0.888mg/L (r=9997) for morin hydrate, and 0.965~7.720mg/L (r=0.9991) for kaempferol. The average recoveries were 90.0%~101.5%. The method is simple and accurate, and can be used for the determination of quercetin, morin hydrate and kaempferol in plants.

  8. The Hill and the Trees

    Institute of Scientific and Technical Information of China (English)

    王燕文

    2007-01-01

    Once there was a well-known hill here. There were many lush trees, beautiful flowers and green grasses on it. One day, the hill said to the trees proudly, “Look, how beautiful I am! But you look so ugly on my back. It must be better if I could drive you away.” One of the trees said, “You won't have beautiful and green clothing without us trees? If you leave us, you will die away.” The hill laughed and said again,”I feel very ashamed for I am staying with you together. Sooner or later I will drive you all...

  9. Quantity and Mass of Particulate Matter Retained on Tree Leaves and Determination Methods%植物叶面滞留颗粒物的数量和质量特征及方法比较

    Institute of Scientific and Technical Information of China (English)

    杨佳; 王会霞; 谢滨泽; 王彦辉; 石辉

    2015-01-01

    为定量认识并寻找可能方法来弥补或修正目前常用的水洗-滤膜法测定植物叶面滞尘能力的不足,更加直观和准确地反映叶面滞尘能力,选择北京市相对清洁的北京植物园和污染严重的国贸桥2个地点,利用环境扫描电镜测定了大叶黄杨( Euonymus japonicas )、国槐( Sophora japonica )、毛白杨( Populus tomentosa )、银杏( Ginkgo biloba)和紫叶李(Prunus cerasifera)5个树种的上、下叶表面滞留的颗粒物(PM)数量和粒径组成,计算出单位植物叶面积滞尘量,并与水洗-滤膜法进行比较。结果表明:植物叶面滞留的颗粒物数量以PM<10(粒径<10μm的颗粒物)为主,占总数的90%以上;污染严重的国贸桥叶表滞留的PM<2�5数量高于相对清洁的北京植物园;采用颗粒物计数法与水洗-滤膜法测定得到的叶面滞尘量之间存在显著线性关系,但两者数值相差很大。有必要进行严格的控制实验来确定导致差异的主要原因与机制,并藉此提出水洗-滤膜法的修正技术或发展多种方法的联合运用技术。%Since the current washing⁃membrance⁃filtering method is not good enough to determine dust⁃retaining capacity of plant leaves, it is essential to quantitatively define some new potential methods to make up or amend shortages of the current method and to determine intuitively and accurately dust⁃retaining capacity of plant leaves. Two sampling sites, the Beijing Botanical Garden and Guomao Bridge, in Beijing were selected. The former is relatively clean and the latter severe⁃ly polluted. Leaves were collected from Euonymus japonicas, Sophora japonica, Populus tomentosa, Ginkgo biloba and Prunus cerasifera in the two sites in Beijing for determination of quantity and particle⁃size composition of particulate matter ( PM) detained on the upper and lower surfaces of the leaves with a scanning electron microscope

  10. Rate of tree carbon accumulation increases continuously with tree size

    Science.gov (United States)

    Stephenson, N.L.; Das, A.J.; Condit, R.; Russo, S.E.; Baker, P.J.; Beckman, N.G.; Coomes, D.A.; Lines, E.R.; Morris, W.K.; Rüger, N.; Álvarez, E.; Blundo, C.; Bunyavejchewin, S.; Chuyong, G.; Davies, S.J.; Duque, Á.; Ewango, C.N.; Flores, O.; Franklin, J.F.; Grau, H.R.; Hao, Z.; Harmon, M.E.; Hubbell, S.P.; Kenfack, D.; Lin, Y.; Makana, J.-R.; Malizia, A.; Malizia, L.R.; Pabst, R.J.; Pongpattananurak, N.; Su, S.-H.; Sun, I-F.; Tan, S.; Thomas, D.; van Mantgem, P.J.; Wang, X.; Wiser, S.K.; Zavala, M.A.

    2014-01-01

    Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle—particularly net primary productivity and carbon storage—increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree’s total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to understand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

  11. Planting Trees

    OpenAIRE

    Relf, Diane

    2009-01-01

    The key aspects in planning a tree planting are determining the function of the tree, the site conditions, that the tree is suited to site conditions and space, and if you are better served by a container-grown. After the tree is planted according to the prescribed steps, you must irrigate as needed and mulch the root zone area.

  12. Environmental fate of emamectin benzoate after tree micro injection of horse chestnut trees.

    Science.gov (United States)

    Burkhard, Rene; Binz, Heinz; Roux, Christian A; Brunner, Matthias; Ruesch, Othmar; Wyss, Peter

    2015-02-01

    Emamectin benzoate, an insecticide derived from the avermectin family of natural products, has a unique translocation behavior in trees when applied by tree micro injection (TMI), which can result in protection from insect pests (foliar and borers) for several years. Active ingredient imported into leaves was measured at the end of season in the fallen leaves of treated horse chestnut (Aesculus hippocastanum) trees. The dissipation of emamectin benzoate in these leaves seems to be biphasic and depends on the decomposition of the leaf. In compost piles, where decomposition of leaves was fastest, a cumulative emamectin benzoate degradation half-life time of 20 d was measured. In leaves immersed in water, where decomposition was much slower, the degradation half-life time was 94 d, and in leaves left on the ground in contact with soil, where decomposition was slowest, the degradation half-life time was 212 d. The biphasic decline and the correlation with leaf decomposition might be attributed to an extensive sorption of emamectin benzoate residues to leaf macromolecules. This may also explain why earthworms ingesting leaves from injected trees take up very little emamectin benzoate and excrete it with the feces. Furthermore, no emamectin benzoate was found in water containing decomposing leaves from injected trees. It is concluded, that emamectin benzoate present in abscised leaves from horse chestnut trees injected with the insecticide is not available to nontarget organisms present in soil or water bodies. PMID:25363584

  13. Environmental fate of emamectin benzoate after tree micro injection of horse chestnut trees.

    Science.gov (United States)

    Burkhard, Rene; Binz, Heinz; Roux, Christian A; Brunner, Matthias; Ruesch, Othmar; Wyss, Peter

    2015-02-01

    Emamectin benzoate, an insecticide derived from the avermectin family of natural products, has a unique translocation behavior in trees when applied by tree micro injection (TMI), which can result in protection from insect pests (foliar and borers) for several years. Active ingredient imported into leaves was measured at the end of season in the fallen leaves of treated horse chestnut (Aesculus hippocastanum) trees. The dissipation of emamectin benzoate in these leaves seems to be biphasic and depends on the decomposition of the leaf. In compost piles, where decomposition of leaves was fastest, a cumulative emamectin benzoate degradation half-life time of 20 d was measured. In leaves immersed in water, where decomposition was much slower, the degradation half-life time was 94 d, and in leaves left on the ground in contact with soil, where decomposition was slowest, the degradation half-life time was 212 d. The biphasic decline and the correlation with leaf decomposition might be attributed to an extensive sorption of emamectin benzoate residues to leaf macromolecules. This may also explain why earthworms ingesting leaves from injected trees take up very little emamectin benzoate and excrete it with the feces. Furthermore, no emamectin benzoate was found in water containing decomposing leaves from injected trees. It is concluded, that emamectin benzoate present in abscised leaves from horse chestnut trees injected with the insecticide is not available to nontarget organisms present in soil or water bodies.

  14. Development and Leaf Consumption by Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) Reared on Leaves of Agroenergy Crops.

    Science.gov (United States)

    Cabezas, M F; Nava, D E; Geissler, L O; Melo, M; Garcia, M S; Krüger, R

    2013-12-01

    Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) is a polyphagous pest that threatens more than 24 species of crop plants including those used for biodiesel production such as Ricinus communis (castor bean), Jatropha curcas (Barbados nut), and Aleurites fordii (tung oil tree). The development and leaf consumption by S. cosmioides reared on leaves of these three species were studied under controlled laboratory conditions. The egg-to-adult development time of S. cosmioides was shortest when reared on castor bean leaves and longest when reared on tung oil tree leaves. Larvae reared on castor bean and Barbados nut leaves had seven instars, whereas those reared on tung oil tree leaves had eight. Females originating from larvae reared on castor bean and Barbados nut leaves showed greater fecundity than did females originating from larvae reared on tung oil tree leaves. Insects fed on castor bean leaves had shorter life spans than those fed on tung oil tree and Barbados nut leaves although the oviposition period did not differ significantly. The intrinsic and finite rates of increase were highest for females reared on castor bean leaves. Total leaf consumption was highest for larvae reared on tung oil tree leaves and lowest for those reared on Barbados nut leaves. We conclude that castor bean is a more appropriate host plant for the development of S. cosmioides than are Barbados nut and tung oil tree. PMID:27193276

  15. Development and Leaf Consumption by Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) Reared on Leaves of Agroenergy Crops.

    Science.gov (United States)

    Cabezas, M F; Nava, D E; Geissler, L O; Melo, M; Garcia, M S; Krüger, R

    2013-12-01

    Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) is a polyphagous pest that threatens more than 24 species of crop plants including those used for biodiesel production such as Ricinus communis (castor bean), Jatropha curcas (Barbados nut), and Aleurites fordii (tung oil tree). The development and leaf consumption by S. cosmioides reared on leaves of these three species were studied under controlled laboratory conditions. The egg-to-adult development time of S. cosmioides was shortest when reared on castor bean leaves and longest when reared on tung oil tree leaves. Larvae reared on castor bean and Barbados nut leaves had seven instars, whereas those reared on tung oil tree leaves had eight. Females originating from larvae reared on castor bean and Barbados nut leaves showed greater fecundity than did females originating from larvae reared on tung oil tree leaves. Insects fed on castor bean leaves had shorter life spans than those fed on tung oil tree and Barbados nut leaves although the oviposition period did not differ significantly. The intrinsic and finite rates of increase were highest for females reared on castor bean leaves. Total leaf consumption was highest for larvae reared on tung oil tree leaves and lowest for those reared on Barbados nut leaves. We conclude that castor bean is a more appropriate host plant for the development of S. cosmioides than are Barbados nut and tung oil tree.

  16. Effect of the air pollution by heavy metals in the tree leaves in the metropolitan area of Toluca Valley; Efecto de la contaminacion atmosferica por metales pesados en las hojas de los arboles de la zona metropolitana del Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Ledesma O, C. I.

    2014-07-01

    Leaves of two tree species: Juniperus sp and Ligustrum sp were studied as indicators of pollution heavy metals (Mn, Fe, Cu, Zn and Pb) in the atmosphere of the Metropolitan Area of the Toluca Valley. Bio markers of catalase, superoxide dismutase, ascorbate peroxidase, guaiacol, proteins and pigments were measured in order to determine the effects to atmospheric stress caused by heave metals during two periods in the year (December 2012 and May 2013). Metals were quantified in dry deposit and tissue on trees tissue leaves using the technique of Energy Dispersive X-ray Fluorescence Spectroscopy and Total Reflection X-ray Fluorescence Spectroscopy respectively. The results show greater response of enzyme inhibition in Juniperus sp. species, with decreased protein content and increased lipid peroxidation at sites with higher content of metals in tissue belonging to urban areas with increased industrial activity and traffic flow. In dry deposit bioavailability factor of metals was Fe>Mn> Zn> Cu>Pb for the first time of sampling and Fe>Mn> Cu> Zn>Pb for the second sampling period. (Author)

  17. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2013-01-01

    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  18. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  19. Tree and tree-like species of Mexico: gymnosperms, monocotyledons, and tree ferns

    OpenAIRE

    Martin Ricker; Hernández, Héctor M.

    2010-01-01

    Trees or tree-like plants are defined here broadly as perennial, self-supporting plants with an adult height of at least 5 m (without ascending leaves or inflorescences), and with 1 or several erect stems with a diameter of at least 10 cm. We present an updated list of all Mexican tree species under that definition in the Gymnospermae (86 species, 38% endemic to Mexico), Monocotyledonae (75 species, 55% endemic), and Pteridophyta (9 species, none endemic). The list contains a total of 170 spe...

  20. Características funcionais de folhas de sol e sombra de espécies arbóreas em uma mata de galeria no Distrito Federal, Brasil Leaf functional traits in sun and shade leaves of gallery forest trees in Distrito Federal, Brazil

    Directory of Open Access Journals (Sweden)

    Davi Rodrigo Rossatto

    2010-09-01

    nutritional aspects of shade and sun leaves, in ten tree species commonly found in gallery forests. Relative to shade leaves, sun leaves had higher values of CO2 assimilation rates on an area basis (Aarea, of stomatal conductance (gs, of quantum yield of Photosystem II (ΦPSIIL; and a larger fraction of PSII centers in the open state (qL, while shade leaves showed higher specific leaf area. However, shade and sun leaves did not differ in terms of leaf water potential, CO2 assimilation on a mass basis and in leaf concentrations of macronutrients. ΦPSII and gs were the main factors that influenced Aarea in sun leaves, while only ΦPSII significantly affected Aarea of shade leaves. The differences found here demonstrate that, like in other forest formations worldwide, gallery forest trees are able to acclimate to contrasting irradiance levels that typically occur in this type of environment.

  1. Trees of Our National Forests.

    Science.gov (United States)

    Forest Service (USDA), Washington, DC.

    Presented is a description of the creation of the National Forests system, how trees grow, managing the National Forests, types of management systems, and managing for multiple use, including wildlife, water, recreation and other uses. Included are: (1) photographs; (2) line drawings of typical leaves, cones, flowers, and seeds; and (3)…

  2. The Biology of Ageing in Leaves.

    Science.gov (United States)

    Gill, John; And Others

    1988-01-01

    Describes laboratory procedures for observing the progressive change deciduous leaves undergo prior to abscission. Outlines the starch test, sugar test, extraction and chromatography of pigments, and experimental results. States that obtained results enable the events of leaf senescence to be correlated with the carbohydrate economy of a tree in…

  3. Talking Trees

    Science.gov (United States)

    Tolman, Marvin

    2005-01-01

    Students love outdoor activities and will love them even more when they build confidence in their tree identification and measurement skills. Through these activities, students will learn to identify the major characteristics of trees and discover how the pace--a nonstandard measuring unit--can be used to estimate not only distances but also the…

  4. 叶山次生落叶阔叶林主要树种空间结构特征%Spatial structure characteristics of main tree species in secondary deciduous broad-leaved forest in Yeshan

    Institute of Scientific and Technical Information of China (English)

    樊丙玉; 郝耀锋; 吴开华; 黄庆丰

    2012-01-01

    通过对铜陵叶山林场天然次生落叶阔叶混交林内具有代表性的样地调查,利用角尺度、混交度和大小比数3个林分空间结构参数分析了该次生落叶阔叶林林分空间结构特征.结果表明,该林分乔木层共有19个树种,麻栎是该森林类型的优势树种,主要伴生树种为化香、枫香、檫木等;该森林类型林分平均角尺度、平均混交度和平均大小比数分别为0.556、0.525和0.497;在林木空间格局上,林分整体呈团状分布;从林分种间隔离程度来看,整体处于中度混交状态;在林木大小分化程度上,麻栎、化香、枫香和檫木在生长上整体处于中庸状态,林木空间大小分化不大.该森林类型还处在不稳定阶段,即落叶阅叶向常绿与落叶阔叶林演替过程中.%Based on the investigation of typical plots of the natural secondary deciduous broadleaved mixed forest in Yeshan Forest-farm of Tongling city, the spatial structure features of this forest type were analyzed by using three spatial structure parameters (uniform angle, mingling degree and neighborhood comparison index). The results showed that there were 19 tree species in tree layer, of which Quercus acutissima was the dominant species of this forest type, and Platycarya strobilacea, Liquidambar formosana, Sassafras tzumus and so on were main associated tree species; the mean value of uniform angle index, mingling degree and neighborhood comparison of the stand in forest type were 0.556, 0.525 and 0.497, respectively. The pattern of tree spatial distribution of the stand was the cluster. The mingling degree of tree species of the stand was moderate mixed. Quercus acutissima, Platycarya strobilacea, Liquidambar formosana and Sassafras tzumus were the mean state in growing in the tree's size differentiation degree. The tree's size differentiation of this forest type was small. This forest type is still in the unstable stage, namely the transition stage from the

  5. Watch out for the leaves!

    CERN Multimedia

    HSE Unit

    2013-01-01

    Now that autumn is here, dead leaves falling from the trees form a colourful carpet that is pleasing to the eye. However, the reality is less pleasant for pedestrians, since these leaves increase the risk of slipping and falling, especially when the ground is wet.   These conditions are also hazardous for two- and four-wheeled vehicles, whose grip on the ground can be severely reduced, thereby increasing the risk of them skidding out of control. Cyclists are among the most vulnerable road users when faced with these hazards. It is therefore essential to be alert to the dangers, which can be lessened by taking a few simple precautions such as moderating your speed and wearing suitable shoes. We also invite you to notify the Service Desk if you notice a road or pavement where there is a high concentration of dead leaves. The CERN Roads and Drainage Service will then ensure that the leaves are cleared in order to reduce the risk of accidents in the area.

  6. Heavy Metals in Barks and Leaves of Coconut Trees and Its Environmental Significance in Haikou and Sanya Cities, Hainan Province%海口和三亚椰树中的重金属元素研究及环境指示意义

    Institute of Scientific and Technical Information of China (English)

    张欣; 吴国爱; 付杨荣; 杨奕; 鲍征宇

    2009-01-01

    In order to study the relationship of heavy metals between coconut trees(Cocos nucifera L.) and the environment, concentrations of Cd, Co, Cr, Cu, Ni, Pb, Zn, Ti and V in bark and leave samples of coconut trees in Haikou and Sanya cities were analyzed. The results show that coconut tree barks and leaves are subject to accumulate Cd, Cu, Pb and Zn. All the studied element concentrations in barks and leaves in Haikou are higher than those in Sanya except Cr and Ni in barks. Both in barks and leaves, the concentration of Pb is significantly higher in roadway sides. The contents of Co, Cr, Ni, Ti and V in the industrial district are almost higher than other areas. We also discussed the biological absorption coefficients (BAC) and elemental correlations between coconut trees and soils, which indicated that the distributions of heavy metals in plants are influenced by soils limitedly and also by their individual biogeochemical characteristics.%采用电感耦合等离子体发射光谱(ICP)和原子吸收光谱仪分析了海口市和三亚市椰树树皮和树叶中Cd、Co、Cu、Cr、Ni、Pb、Zn、V、Ti的质量分数,探讨了它们的分布特征.结果表明,椰树树皮较树叶更易积累重金属元素.对比两个城市椰树树皮、树叶中各重金属元素的质量分数可知,除三亚市椰树树皮中Cr、Ni的平均质量分数略高于海口市外,椰树树皮、树叶中其他重金属元素质量分数均为海口市大于三亚市.分析不同功能区椰树树皮和树叶中各重金属元素的质量分数可见,工业区中Co、Cr、Ni、Ti、V的质量分数相对较高,反映了工业活动对环境的影响;主干道附近w(Pb)较高,与车辆交通等人为活动密切相关.对重金属元素的相关性及生物吸收系数的分析表明,椰树对土壤中各重金属元素的吸收程度是有限的,其吸收程度与土壤中各重金属元素质量分数的高低并不一致,因此,其吸收程度除受土壤类型影响外,还受生物吸收能力的控制.

  7. Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

    Science.gov (United States)

    Madrigal-González, Jaime; Ruiz-Benito, Paloma; Ratcliffe, Sophia; Calatayud, Joaquín; Kändler, Gerald; Lehtonen, Aleksi; Dahlgren, Jonas; Wirth, Christian; Zavala, Miguel A.

    2016-01-01

    Neglecting tree size and stand structure dynamics might bias the interpretation of the diversity-productivity relationship in forests. Here we show evidence that complementarity is contingent on tree size across large-scale climatic gradients in Europe. We compiled growth data of the 14 most dominant tree species in 32,628 permanent plots covering boreal, temperate and Mediterranean forest biomes. Niche complementarity is expected to result in significant growth increments of trees surrounded by a larger proportion of functionally dissimilar neighbours. Functional dissimilarity at the tree level was assessed using four functional types: i.e. broad-leaved deciduous, broad-leaved evergreen, needle-leaved deciduous and needle-leaved evergreen. Using Linear Mixed Models we show that, complementarity effects depend on tree size along an energy availability gradient across Europe. Specifically: (i) complementarity effects at low and intermediate positions of the gradient (coldest-temperate areas) were stronger for small than for large trees; (ii) in contrast, at the upper end of the gradient (warmer regions), complementarity is more widespread in larger than smaller trees, which in turn showed negative growth responses to increased functional dissimilarity. Our findings suggest that the outcome of species mixing on stand productivity might critically depend on individual size distribution structure along gradients of environmental variation. PMID:27571971

  8. Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

    Science.gov (United States)

    Madrigal-González, Jaime; Ruiz-Benito, Paloma; Ratcliffe, Sophia; Calatayud, Joaquín; Kändler, Gerald; Lehtonen, Aleksi; Dahlgren, Jonas; Wirth, Christian; Zavala, Miguel A.

    2016-08-01

    Neglecting tree size and stand structure dynamics might bias the interpretation of the diversity-productivity relationship in forests. Here we show evidence that complementarity is contingent on tree size across large-scale climatic gradients in Europe. We compiled growth data of the 14 most dominant tree species in 32,628 permanent plots covering boreal, temperate and Mediterranean forest biomes. Niche complementarity is expected to result in significant growth increments of trees surrounded by a larger proportion of functionally dissimilar neighbours. Functional dissimilarity at the tree level was assessed using four functional types: i.e. broad-leaved deciduous, broad-leaved evergreen, needle-leaved deciduous and needle-leaved evergreen. Using Linear Mixed Models we show that, complementarity effects depend on tree size along an energy availability gradient across Europe. Specifically: (i) complementarity effects at low and intermediate positions of the gradient (coldest-temperate areas) were stronger for small than for large trees; (ii) in contrast, at the upper end of the gradient (warmer regions), complementarity is more widespread in larger than smaller trees, which in turn showed negative growth responses to increased functional dissimilarity. Our findings suggest that the outcome of species mixing on stand productivity might critically depend on individual size distribution structure along gradients of environmental variation.

  9. A biochemical model of photosynthesis for mango leaves: evidence for the effect of fruit on photosynthetic capacity of nearby leaves.

    Science.gov (United States)

    Urban, L; Le Roux, X; Sinoquet, H; Jaffuel, S; Jannoyer, M

    2003-04-01

    Variations in leaf nitrogen concentration per unit mass (Nm) and per unit area (Na), mass-to-area ratio (Ma), total nonstructural carbohydrates (Ta), and photosynthetic capacity (maximum carboxylation rate, electron transport capacity, rate of phosphate release in triose phosphate utilization and dark respiration rate) were studied within the digitized crowns of two 3-year-old mango trees (Mangifera indica L.) on La Réunion Island. Additional measurements of Nm, Na, Ma, Ta and photosynthetic capacities were performed on young, fully expanded leaves of 11-year-old mango trees. Leaves of similar gap fractions were taken far from and close to developing fruits. Unlike Nm, both Na and Ta were linearly correlated to gap fraction. Similar relationships were found for all leaves whatever their age and origin, except for Ta, for which we found a significant tree effect. Photosynthetic capacity was nonlinearly correlated to Na, and a unique relationship was obtained for all types of leaves. Photosynthetic acclimation to light was mainly driven by changes in Ma, but allocation of total leaf N between the different photosynthetic functions also played a substantial role in acclimation to the lowest irradiances. Leaves close to developing fruits exhibited a higher photosynthetic capacity than other leaves, but similar Ta. Our data suggest that Ta does not control photosynthetic capacity in mango leaves. We used the data to parameterize a biochemically based model of photosynthesis and an empirical stomatal conductance model, allowing accurate predictions of net photosynthesis of leaves in field-grown mango trees.

  10. Holy Trees

    OpenAIRE

    Elosua, Miguel

    2013-01-01

    Puxi's streets are lined with plane trees, especially in the former French Concession (and particularly in the Luwan and Xuhui districts). There are a few different varieties of plane tree, but the one found in Shanghai, is the hybrid platane hispanica. In China they are called French Plane trees (faguo wutong - 法国梧桐), for they were first planted along the Avenue Joffre (now Huai Hai lu - 淮海路) in 1902 by the French. Their life span is long, over a thousand years, and they may grow as high as ...

  11. Tree and tree-like species of Mexico: Asteraceae, Leguminosae, and Rubiaceae

    OpenAIRE

    Martin Ricker; Hernández, Héctor M.; Mario Sousa; Helga Ochoterena

    2013-01-01

    Trees or tree-like plants are defined here broadly as perennial, self-supporting plants with a total height of at least 5 m (without ascending leaves or inflorescences), and with one or several erect stems with a diameter of at least 10 cm. We continue our compilation of an updated list of all native Mexican tree species with the dicotyledonous families Asteraceae (36 species, 39% endemic), Leguminosae with its 3 subfamilies (449 species, 41% endemic), and Rubiaceae (134 species, 24% endemic)...

  12. Game tree algorithms and solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie)

    1998-01-01

    textabstractIn this paper, a theory of game tree algorithms is presented, entirely based upon the concept of solution tree. Two types of solution trees are distinguished: max and min trees. Every game tree algorithm tries to prune nodes as many as possible from the game tree. A cut-off criterion in

  13. Hevea Leaves Boundary Identification based on Morphological Transformation and Edge Detection Features

    Directory of Open Access Journals (Sweden)

    Sule Tekkesinoglu

    2014-03-01

    Full Text Available The goal of this study is to present a concept to identify overlapping rubber tree (Hevea brasiliensis-scientific name leaf boundaries. Basically rubber tree leaves show similarity to each other and they may contain similar information such as color, texture or shape of leaves. In fact rubber tree leaves are naturally in class of palmate leaves, it means that numbers of leaves are joining at their base. So it reflects the information of the position of the leaves whether the leaves are overlapped or separated. Therefore, this unique feature could be used to distinguish particular leaves from others clone to identify the type of trees. This study addresses the problem of identifying the overlapped leaves with complex background. The morphological transformation is often applied in order to obtain the foreground object and the background location as well. However, it does not yield satisfactory results in order to get boundaries information. This study, presents on improved approach to identify boundary of rubber tree leaves based on morphological operation and edge detection methods. The outcome of this fused algorithm exhibits promising results for identifying the leaf boundaries of rubber trees.

  14. To leave or not to leave.

    Science.gov (United States)

    Buchan, James

    2016-06-22

    Lies, damned lies and Brexit statistics. It's not been a good month for anyone espousing evidence-based policy and politics after the chair of the Commons health committee switched from Leave to Remain, citing misuse of data by the Leave campaign. PMID:27332589

  15. Interpreting Tree Ensembles with inTrees

    OpenAIRE

    Deng, Houtao

    2014-01-01

    Tree ensembles such as random forests and boosted trees are accurate but difficult to understand, debug and deploy. In this work, we provide the inTrees (interpretable trees) framework that extracts, measures, prunes and selects rules from a tree ensemble, and calculates frequent variable interactions. An rule-based learner, referred to as the simplified tree ensemble learner (STEL), can also be formed and used for future prediction. The inTrees framework can applied to both classification an...

  16. 果尔除草剂在阔叶树种育苗中应用试验%The application of oxyfluorfen herbicides in broad leaved tree species seedlings

    Institute of Scientific and Technical Information of China (English)

    王玲

    2014-01-01

    Weeding seeding process is an important link of production, artificial weeding cost high, in the rainy season often form a drunk, to solve this problem, the design of test fruit herbicide concentration, concentration by variance analysis to find out the goal herbicide in the Broadleaved Tree Species Seedlings in the best herbicidal effect. To solve the field in the nursery work weeding problems.%育苗过程中除草是一项重要的生产环节,人工除草成本高,在雨季往往会形成草荒,针对这一难题,此次设计不同浓度的果儿除草剂试验,通过方差分析找出果尔除草剂在阔叶树种育苗过程中最佳除草效果的浓度,以解决在育苗工作中的除草难题。

  17. A suffix tree or not a suffix tree?

    DEFF Research Database (Denmark)

    Starikovskaya, Tatiana; Vildhøj, Hjalte Wedel

    2015-01-01

    In this paper we study the structure of suffix trees. Given an unlabeled tree τ on n nodes and suffix links of its internal nodes, we ask the question “Is τ a suffix tree?”, i.e., is there a string S whose suffix tree has the same topological structure as τ? We place no restrictions on S...... if τ is a suffix tree is not an easy task, because, with no restrictions on the final symbol, we cannot guess the length of a string that realizes τ from the number of leaves. And without an upper bound on the length of such a string, it is not even clear how to solve the problem by an exhaustive...... search. In this paper, we prove that τ is a suffix tree if and only if it is realized by a string S of length n-1, and we give a linear-time algorithm for inferring S when the first letter on each edge is known. This generalizes the work of I et al. (2014) [15]. [All rights reserved Elsevier]....

  18. Producción de tilapia nilótica (Oreochromis niloticus L. utilizando hojas de chaya (Cnidoscolus chayamansa McVaugh como sustituto parcial del alimento balanceado Nile tilapia production (Oreochromis niloticus L. using tree spinach leaves (Cnidoscolus chayamansa McVaugh as a partial substitute for balanced feed

    Directory of Open Access Journals (Sweden)

    Gaspar R Poot-López

    2012-11-01

    with a limited food supply. In rural areas, the availability of alternative inputs is key to improving fish farming production, especially if these inputs are unprocessed. The leaves of tree spinach (Cnidoscolus chayamansa, a bush that grows in Mexico and Central and South America, are one such option. In this work, juvenile tilapia (7-4.5 g survival, growth rates, and food conversion rates were studied during two seasons (warm and cold, substituting 25 and 50% of the balanced feed rations with raw tree spinach leaves (ad libitum. The experimental design was completely random, with two treatments and one control (00% of the balanced feed ration; three replicates were done in each season. The densities were 36 fish m-per replica in the cold season and 44 fish m-3 per replica in the warm season. The weight gain in the treatments with 50 and 75% balanced feed and tree spinach leaves was similar to that of the control group in both seasons. The cold season adversely affected survival, weight gain, and feed conversion rates in all treatments, but the warm season did not. When tree spinach leaves were included in the tilapia diet, the feed conversion rate for the balanced feed was reduced from 9.7 to 33.62% in the cold season and from 5.38 to 40.23% in the warm season. The results show that the use of locally available complementary inputs such as tree spinach leaves may favor the development of small-scale tilapia cultures in the tropics.

  19. What Good Is a Tree?

    Institute of Scientific and Technical Information of China (English)

    Lowell; Ponte; 史书碧

    1998-01-01

    文章开头说:Trees are so common and quiet that we pay them little mind. 其实,初见此标题——What Good Is a Tree?笔者也pay this essay little mind。这个题目还能够讲出多少新意来呢?不料,细读之后,竟不忍释手! Trees sustain our lives and our planet in a thousand practical ways. Trees do more than make life pleasant;they make life possible. 这是文章的两句主题句。读罢全文,认真一想,便觉这决非耸人听闻之言:无言的树,“挪死”的树,支撑着我们这个星球,庇护着天下的生灵!诸如: …they draw carbon dioxide from the air…and oxygen iS released. Without tree our entire world would be a much drier place. For centuries,the Chinese have derived medicines form the ginkgo tree. 让读者双眼一亮的是,文章提供了许多你我都不曾想到的有关树的信息: a.树木能彼此互通信息: …trees send unseen signals to each other.When willows are attacked bywebworms and tent caterpillars,they give off a chemical that alerts nearby trees.Theneighboring trees respond by pumping more tannin into their leaves,making them moredifficult for the insects tO digest。 更让人?

  20. Leaving home in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Rikke Skovgaard

    2015-01-01

    The paper focuses on ethnic differences in the timing and patterns of leaving the parental home. Leaving home is a key transition in the life course of the individual, and extensive research has been conducted on the timing and patterns of leaving it. However, ethnic differences in these patterns...

  1. Aspen Trees.

    Science.gov (United States)

    Canfield, Elaine

    2002-01-01

    Describes a fifth-grade art activity that offers a new approach to creating pictures of Aspen trees. Explains that the students learned about art concepts, such as line and balance, in this lesson. Discusses the process in detail for creating the pictures. (CMK)

  2. Arginine, scurvy and Cartier's "tree of life"

    OpenAIRE

    Durzan Don J

    2009-01-01

    Abstract Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compoun...

  3. 阿克苏市城郊林10种果树叶面形态与滞尘量的关系%Relationship between Morphological Structure and Dust-holding Capacity of Ten Fruit Tree Leaves in Peri-urban Area of Aksu

    Institute of Scientific and Technical Information of China (English)

    迈迪娜·吐尔逊; 玉米提·哈力克; 祖皮艳木·买买提; 阿衣古丽·艾力亚斯

    2016-01-01

    As an important component of urban ecosystem,suburb orchard forests can not only supply many kinds of fruit for urban residents,but also provide sustainable ecological services that were beneficial for the cities and their residents.A comparison study was conducted on the amount of the dust retained by the leaves of trees among 10 fruit species in Kokyar artificial afforestation project in the suburb area of Aksu,a typical oasis city in Sothern Xinjiang.The results showed that the ten fruit tree species could be classified into three categories based on the amount of the dust retained.The first category that had the highest amount of the dust retained included Vitis vini fera > Pyrus sinkiangensis>Ziziphus jujuba >Juglans regia,followed by the second category,including Ficus carica > Punicagranatum>Armeniaca vulgaris,and the third one,including Prunus pseudocerasus > Amnygdalus persica > Malus pumila.In conclusion,trees with big leaf area,coarse surface,short petiole,moderate height and crown demonstrated strong dust-retaining capability.The relationship between leaf morphological structure and the dust-retaining capacity investigation indicated that the leaves which had high dust retaining capability were those with more prominent main leaf veins,more intensive and more closely arrayed lateral veins.It was suggested that native fruit trees with high dust retaining ability should be used for the affforestion in suburb area.%城郊经济防护林是城市绿地系统的重要组成部分,不仅能够提供各类水果,而且为城市及其居民持续获得自然生态服务提供保障.本研究对新疆南部典型绿洲城市——阿克苏市郊柯柯牙人工经济防护林10种果树叶面滞尘量及其差异进行对比与排序.结果表明:10种果树的叶面滞尘量可分为3类,第1类滞尘量高(>3.00 mg·cm 2),包括葡萄、香梨、红枣和核桃,其滞尘量分别为5.37、4.55、3.88、3.03 mg· cm-2;第2类的滞尘量中等(1

  4. Doenças foliares, cancro e número de frutos relacionados com a adubação nitrogenada em pessegueiro Leave diseases, canker and number of fruits related with the nitrogen fertilizer in peach trees

    Directory of Open Access Journals (Sweden)

    Silvana Regina de Souza

    2007-08-01

    , sem reflexos sobre a desfolha.With the introduction of an integrated production of peaches (PI in Paraná, some modifications during the handling of this culture were necessary, in order to adapt it to the regional conditions. The Nitrogen fertilizer was recommended to PI from Rio Grande do Sul and it stated a maximum of 80 kg/ha of nitrogen (N annually, becoming a limiting factor to the high productivity reached by some producers in the State of Parana. On the other hand, the increasing of the nitrogen dosage may favor a major incidence of leave and branch diseases, damaging the development of the plants. The present work aimed to evaluate the effect of nitrogen fertilizer in the production and in three diseases, cultivated in the PI system. An experiment in Lapa was carried through with the Chimarrita Cultivar, with three treatments (40, 80 and 160 kg/ha of N and six repetitions. The production was evaluated counting the number of total fruits for useful plant in the harvest. For evaluation of the diseases the number was determined by the number of lesions (cankers of Botryosphaeria dothidea in a marked plant of each fragment, two years in a row (2003 and 2004, in the period after flowering, shot hole (Wilsonomyces carpophilus was determined by the incidence of the disease in the year of 2002 and to rust (Tranzschelia discolor it was evaluated the incidence and severity in 2003 and 2004. With the data of the rust severity the progress curve of the disease and the fall of the leaves index in the period were obtained. In the third year it was observed that in the dose of 160 kg/ha of N the number of fruits was significant and bigger than in the other treatments. It was observed the growth of the incidence of cankers among the years, however without significant result for the different dosages of nitrogen. The shot hole also was not influenced by the treatments. The area below the progress curve of the diseases (AACPD for rust severity was 20,7 % superior to the minor

  5. Unimodular trees versus Einstein trees

    Science.gov (United States)

    Álvarez, Enrique; González-Martín, Sergio; Martín, Carmelo P.

    2016-10-01

    The maximally helicity violating tree-level scattering amplitudes involving three, four or five gravitons are worked out in Unimodular Gravity. They are found to coincide with the corresponding amplitudes in General Relativity. This a remarkable result, insofar as both the propagators and the vertices are quite different in the two theories.

  6. 针阔混交林不同演替阶段表层土壤理化性质与优势林木生长的相关性%Correlation between the Growth of Dominant Trees and Surface Soil Physiochemical Properties of Conifer and Broad-Leaved Mixed Forest at Different Succession Stages

    Institute of Scientific and Technical Information of China (English)

    林文树; 穆丹; 王丽平; 邵立郡; 吴金卓

    2016-01-01

    论】毛管孔隙度、速效钾和全磷含量是影响不同演替阶段土壤质量的主要因子;经过不同演替阶段,表层土壤理化性质质量的综合得分表现为中龄林<成熟林<近熟林<老龄林;随着演替进行,针阔混交林的表层土壤理化性质基本呈现质量提高趋势,到老龄林时期达到最佳。本研究得到的不同演替阶段针阔混交林林木生长与表层土壤理化性质特征的相关性为进一步实现该地区森林可持续经营提供了科学依据。%[Objective]This study aims to analyze the relationship between surface soil physiochemical properties and the growth of dominant trees for mixed forest of conifer and broad-leaved species at different succession stages in order to explore the growth patterns of different stands and provide basis for sustainable forest management. [Method]The mixed forest conifers and broad-leaved trees at different succession stages ( middle-aged forest,near-mature forest,mature forest, and old growth forest) in Jiaohe Management Bureau of Forestry Experimental Area,Jilin Province were studied. The methods of comparison and principal component analysis were used to analyze physical and chemical properties of the surface soil,the growth of dominant trees,and the relationship between them.[Result]with the succession of forest,the average diameter at breast height ( DBH) of the dominant tree species increased,the average tree height varied slightly, the regeneration of Pinus koraiensis tended to be stable,and the number of Juglans mandshurica,Ulmus davidiana var. japonica ,and U. macrocarpa gradually decreased in the upper overstory. With respect to the soil physical properties,the soil density was not significantly different among middle-aged forest,near-mature forest and mature forest and it reached the minimum at the stage of old-growth forest. With the succession of forest,the non-capillary porosity gradually decreased and capillary porosity

  7. Negative leave balances

    CERN Document Server

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  8. Negative leave balances

    CERN Document Server

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

  9. 闽北天然阔叶林径阶材种结构分析及出材率表的编制%Compilation of Output Structure of Diameter Grade Wood Assortments and Volume Ratio Table for Natural Broad-Leaved Forest Tree Species in North Fujian Province

    Institute of Scientific and Technical Information of China (English)

    李晓景; 江希钿; 庄崇洋; 李小铃

    2012-01-01

    应用闽北天然阔叶林现场造材资料,在分析径阶材种结构规律的基础上,选择适合的方程建立材种出材率模型并编制二元材种出材率表.经检验,该表精度较高,在林业生产上有实用价值.为方便生产中应用,还建立了树高曲线模型,由二元材种出材率袁导出了一元材种出材率表.%The volume ratio model of wood assortment was built by choosing the proper equation, and the two dimension merchantable wood assortment volume yielding rate tables were compiled based on structure analyses of diameter grade wood assortments, with on the spot sample timber data collected from the natural broad-leaved forests in the north Fujian Province. The wood assortment volume yielding rate tables were tested to be with high precision and practicable in forestry production. In order to facilitate the production and application, tree height model was established, and the one dimension merchantable wood assortment volume yielding rate tables were derived from the two dimension tables.

  10. Longevity of guard cell chloroplasts in falling leaves: implication for stomatal function and cellular aging

    Energy Technology Data Exchange (ETDEWEB)

    Zeiger, E.; Schwartz, A.

    1982-11-12

    Guard cell chloroplasts in senescing leaves from 12 species of perennial trees and three species of annual plants survived considerably longer than their mesophyll counterparts. In Ginkgo biloba, stomata from yellow leaves opened during the day and closed at night; guard cell chloroplasts from these leaves showed fluorescence transients associated with electron transport and photophosphorylation. These findings indicate that guard cell chloroplasts are highly conserved throughout the life-span of the leaf and that leaves retain stomatal control during senescence.

  11. Tree for all reasons

    Energy Technology Data Exchange (ETDEWEB)

    Sang, T.

    1980-04-01

    For centuries Chinese peasants have planted paulownia trees, not only for their beauty but also for their fast-growing characteristics - an amazing average of 0.37 cubic meters of timber per year. The leaves, flowers, fruits and bark can be used as medicines and, because of their high nitrogen content the leaves are used as fodder. But above all, paulownias are increasingly being used by Chinese peasants to boost grain output. In Lanka county, Henan province, for example, grain output has increased to an average of 5.25 tons per hectare from less than 0.75 tons in 1963 when paulownia interplanting as a system was introduced. They help crops to withstand sandstorms, droughts and frosts, they increase air humidity and reduce evaporation of moisture in the fields. They do not compete with crops for fertilizer and water since about 80% of their absorbing roots reach a depth of 40-100 cm, while most cereals roots are less than 40 cm.

  12. Combinatorics of distance-based tree inference.

    Science.gov (United States)

    Pardi, Fabio; Gascuel, Olivier

    2012-10-01

    Several popular methods for phylogenetic inference (or hierarchical clustering) are based on a matrix of pairwise distances between taxa (or any kind of objects): The objective is to construct a tree with branch lengths so that the distances between the leaves in that tree are as close as possible to the input distances. If we hold the structure (topology) of the tree fixed, in some relevant cases (e.g., ordinary least squares) the optimal values for the branch lengths can be expressed using simple combinatorial formulae. Here we define a general form for these formulae and show that they all have two desirable properties: First, the common tree reconstruction approaches (least squares, minimum evolution), when used in combination with these formulae, are guaranteed to infer the correct tree when given enough data (consistency); second, the branch lengths of all the simple (nearest neighbor interchange) rearrangements of a tree can be calculated, optimally, in quadratic time in the size of the tree, thus allowing the efficient application of hill climbing heuristics. The study presented here is a continuation of that by Mihaescu and Pachter on branch length estimation [Mihaescu R, Pachter L (2008) Proc Natl Acad Sci USA 105:13206-13211]. The focus here is on the inference of the tree itself and on providing a basis for novel algorithms to reconstruct trees from distances.

  13. Finite Sholander Trees, Trees, and their Betweenness

    CERN Document Server

    Chvátal, Vašek; Schäfer, Philipp Matthias

    2011-01-01

    We provide a proof of Sholander's claim (Trees, lattices, order, and betweenness, Proc. Amer. Math. Soc. 3, 369-381 (1952)) concerning the representability of collections of so-called segments by trees, which yields a characterization of the interval function of a tree. Furthermore, we streamline Burigana's characterization (Tree representations of betweenness relations defined by intersection and inclusion, Mathematics and Social Sciences 185, 5-36 (2009)) of tree betweenness and provide a relatively short proof.

  14. Effects of open-top chambers on 'Valencia' orange trees

    Energy Technology Data Exchange (ETDEWEB)

    Olszyk, D.M.; Takemoto, B.K.; Kats, G.; Dawson, P.J.; Morrison, C.L.

    1992-01-01

    Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. Long-term ozone average concentrations (12 hours, growing season) were 8% lower, and cumulative ozone dose (hourly values >0.1 microL/L) was 29% lower in ambient chambers compared to outside air. Fruit yields were much higher (>39%) for ambient chamber trees than for outside trees over three harvests, due at least partly to less fruit drop during the growing season for ambient chamber trees. Ambient chamber trees were much larger than outside trees and produced over twice as much leaf material over four years of study. Leaves on ambient chamber trees were larger and less dense than on outside trees. Leaves on ambient chamber trees were under more stress than leaves on outside trees during summer months; with lower stomatal conductances (14% average) and transpiration rates (12%), and more negative leaf water pressure potentials (28%). In contrast, leaves on ambient chamber trees had higher net photosynthetic rates (13%) and higher leaf starch concentrations prior to tree flowering (31%), than leaves on outside trees. While these results indicated large long-term impacts on tree growth which must be considered when using open-top chambers, they did not indicate any net effect of chambers on the air pollutant susceptibility of trees which would limit the usefulness of chamber tree data for air quality impact assessment purposes.

  15. Extracting Conflict-free Information from Multi-labeled Trees

    CERN Document Server

    Deepak, Akshay; McMahon, Michelle M

    2012-01-01

    A multi-labeled tree, or MUL-tree, is a phylogenetic tree where two or more leaves share a label, e.g., a species name. A MUL-tree can imply multiple conflicting phylogenetic relationships for the same set of taxa, but can also contain conflict-free information that is of interest and yet is not obvious. We define the information content of a MUL-tree T as the set of all conflict-free quartet topologies implied by T, and define the maximal reduced form of T as the smallest tree that can be obtained from T by pruning leaves and contracting edges while retaining the same information content. We show that any two MUL-trees with the same information content exhibit the same reduced form. This introduces an equivalence relation in MUL-trees with potential applications to comparing MUL-trees. We present an efficient algorithm to reduce a MUL-tree to its maximally reduced form and evaluate its performance on empirical datasets in terms of both quality of the reduced tree and the degree of data reduction achieved.

  16. Arthropod but not bird predation in ethiopian homegardens is higher in tree-poor than in tree-rich landscapes.

    Directory of Open Access Journals (Sweden)

    Debissa Lemessa

    Full Text Available Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7-9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests.

  17. Arthropod but not bird predation in ethiopian homegardens is higher in tree-poor than in tree-rich landscapes.

    Science.gov (United States)

    Lemessa, Debissa; Hambäck, Peter A; Hylander, Kristoffer

    2015-01-01

    Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7-9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests. PMID:25961306

  18. Comparative Characterization of Total Flavonol Glycosides and Terpene Lactones at Different Ages, from Different Cultivation Sources and Genders of Ginkgo biloba Leaves

    OpenAIRE

    Yong Qin; Jin-Ao Duan; Dawei Qian; Chun Jin; Shulan Su; Sheng Guo; Yuping Tang; Erxin Shang; Guisheng Zhou; Xin Yao

    2012-01-01

    The extract from Ginkgo biloba leaves has become a very popular plant medicine and herbal supplement for its potential benefit in alleviating symptoms associated with peripheral vascular disease, dementia, asthma and tinnitus. Most research on G. biloba leaves focus on the leaves collected in July and August from four to seven year-old trees, however a large number of leaves from fruit cultivars (trees older than 10 years) are ignored and become obsol...

  19. Modular Tree Automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular r...

  20. Tree size as a factor influencing leaf emergence and leaf fall in Acacia nigrescens and Combretum apiculatum in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    P. Novellie

    1989-10-01

    Full Text Available In Acacia nigrescens and Combretum apiculatum saplings tended to retain leaves over the dry season, whereas the mature trees generally lost most of their leaves. In Acacia nigrescens the production of new leaves over the dry season was more commonly observed in saplings than in mature trees.

  1. Studies on Photosynthetic Characteristics of Plum Leaves

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Many photosynthetic characteristics of three plum varieties were studied with a infrared CO2 analyzer. Results showed that plums belong to light-loving species,having a relative high light compensation point (75~ 80μmol · m-2 · s-1 ), In natural light range from none to 1400μmol · m-2s-1PAR,the light response curve of plum as a hyperbo and the net photosynthetic rate(Pn) in leavs increased with PA elevation. Pn of plum tree was 20 to 22.50mg CO2 · dm-1 · h-1 at 1380μmol · m-2 · s-1 PAR,indicating that plum was typi cal C3-type fruit tree. Diurnal change in Pn was a bimoal curve with the highest photosynthetic rate arising at about 10:00 a. m. indicated the clear“none-rest”characteristic in plum leaves. Among three varieties. SuiLi3 had the shortest“none-rest“time followed by JiLin6 and NuXinLi. Seasonal change in Pn was a bi modal curve with the first period of high Pn in late June and the second in late August. Pn in leaves decreased visibly in period of drought in Spring and Summer.

  2. Men on Parental Leave

    OpenAIRE

    Trutnovská, Aneta

    2014-01-01

    The aim of this thesis is based on the scientific literature related to the topic, and interviews with specific men on parental leave to point out, in particular, on the grounds that affect men, to the decision to become a full-time father, find out how these families work, and also to point out responses or opinions around which these men often encounter. The theoretical part is devoted to male parental leave in terms of its relation to the children, the themes taking on parental leave, the ...

  3. Chlorophyll dynamics in leaves of Platanus orientalis L. and P. acerifolia willd. in the conditions of environmental pollution

    Directory of Open Access Journals (Sweden)

    N. V. Kapelyush

    2005-11-01

    Full Text Available The state of pigmentary system of plants Platanus orientalis and P. acerifolia under conditions of environmental pollution was studied. Green pigments in leaves of Platanus acerifolia are more resistant to environmental pollution in comparison with Platanus orientalis leaves. The abundance of chloroplasts per a unit of area decreases in leaves of both plane-tree species.

  4. Soil mineral N dynamics beneath mixtures of leaves from legume and fruit trees in Central Amazonian multi-strata agroforests Dinâmica do nitrogênio mineral no solo em misturas de folhas de leguminosas arbóreas e de fruteiras em sistemas agroflorestais multiestratificados na Amazônia Central

    Directory of Open Access Journals (Sweden)

    Carol Melanie Schwendener

    2007-01-01

    Full Text Available Long term applications of leguminous green mulch could increase mineralizable nitrogen (N beneath cupuaçu trees produced on the infertile acidic Ultisols and Oxisols of the Amazon Basin. However, low quality standing cupuaçu litter could interfere with green mulch N release and soil N mineralization. This study compared mineral N, total N, and microbial biomass N beneath cupuaçu trees grown in two different agroforestry systems, north of Manaus, Brazil, following seven years of different green mulch application rates. To test for net interactions between green mulch and cupuaçu litter, dried gliricidia and inga leaves were mixed with senescent cupuaçu leaves, surface applied to an Oxisol soil, and incubated in a greenhouse for 162 days. Leaf decomposition, N release and soil N mineralization were periodically measured in the mixed species litter treatments and compared to single species applications. The effect of legume biomass and cupuaçu litter on soil mineral N was additive implying that recommendations for green mulch applications to cupuaçu trees can be based on N dynamics of individual green mulch species. Results demonstrated that residue quality, not quantity, was the dominant factor affecting the rate of N release from leaves and soil N mineralization in a controlled environment. In the field, complex N cycling and other factors, including soil fauna, roots, and microclimatic effects, had a stronger influence on available soil N than residue quality.Aplicações a longo prazo de leguminosas como adubo verde podem aumentar o nitrogênio (N mineralizável sob árvores de cupuaçu em solos pouco férteis e ácidos (Ultisols e Oxisols da Bacia Amazônica. Entretanto, a baixa qualidade da liteira de cupuaçu pode influênciara liberação de N do adubo verde e a mineralização deste no solo. Neste estudo foram comparados o N mineral, N total, e o N da biomassa microbiana sob árvores de cupuaçu cultivadas em dois sistemas

  5. PHARMACOGNOSTICAL EVALUATIONS OF THE LEAVES OF ZIZIPHUS MAURITIANA

    Directory of Open Access Journals (Sweden)

    Ramesh Kumar Singh et al.

    2012-03-01

    Full Text Available Ziziphus mauritiana belongs to family Rhamnaceae and commonly known as Indian jujube or ber. The leaves are alternate and elliptic. Flowers are small and bisexual. The leaves are about 2.5 – 3.2 cm long. Commercially it is cultivated in China & India. Ziziphus mauritiana is small to medium sized spiny tree. The chemical compositions of the leaves are proteins & amino acids, flavonoids, alkaloids, glycosides, terpenoides, saponins, fibers, tannins and phenolic compounds. Leaves are used in the treatment of diarrhoea, gastric disorder, fever, liver damage and pulmonary disorders. The present work deals to summarize the Pharmacognostical studies like ash value, extractive value, moisture content, volatile matters, crude fibers, phytochemical test, fluorescence analysis and micro chemical test. The alcoholic and aqueous extract of Ziziphus mauritiana leave shows hepatoprotective, antioxidant and other important pharmacological activities. The results of above parameters show the clue for more medicinal properties of Ziziphus mauritiana.

  6. Bronchi, Bronchial Tree, & Lungs

    Science.gov (United States)

    ... specific Modules Resources Archived Modules Updates Bronchi, Bronchial Tree, & Lungs Bronchi and Bronchial Tree In the mediastinum , at the level of the ... trachea. As the branching continues through the bronchial tree, the amount of hyaline cartilage in the walls ...

  7. Falling for Clay Leaves.

    Science.gov (United States)

    Kernan, Christine

    2002-01-01

    Describes an art project that integrated science and art education. Explains that students create ceramic bowls by using real leaves. Discusses the process of creating the ceramic bowls, including how to glaze the bowls. Includes a list of materials. (CMK)

  8. Flavonoids from leaves of Mauritia flexuosa

    OpenAIRE

    Djalma M. Oliveira; Ezequias P. Siqueira; Yule R. F. Nunes; Betania B Cota

    2013-01-01

    The chromatographic fractionation of the Mauritia flexuosa L. f., Arecaceae, leaves extract, a plant known by the name of buriti palm tree, resulted in the isolation of six flavonoids: tricin-7-O-rutinoside, apigenin-6-C-arabinoside, 8-C-glucoside (isoschaftoside), kaempferol-3-O-rutinoside (nicotiflorine), quercetin-3-O-rutinoside (rutin), luteolin-8-C-glucoside (orientin) and luteolin-6-C-glucoside (isoorientin). The flavonoids were found out and previously reported as constituents of the ...

  9. Image-Based Modeling of Plants and Trees

    CERN Document Server

    Kang, Sing Bang

    2009-01-01

    Plants and trees are among the most complex natural objects. Much work has been done attempting to model them, with varying degrees of success. In this book, we review the various approaches in computer graphics, which we categorize as rule-based, image-based, and sketch-based methods. We describe our approaches for modeling plants and trees using images. Image-based approaches have the distinct advantage that the resulting model inherits the realistic shape and complexity of a real plant or tree. We use different techniques for modeling plants (with relatively large leaves) and trees (with re

  10. The Tree Inclusion Problem: In Linear Space and Faster

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2011-01-01

    Given two rooted, ordered, and labeled trees P and T the tree inclusion problem is to determine if P can be obtained from T by deleting nodes in T. This problem has recently been recognized as an important query primitive in XML databases. Kilpel äinen and Mannila [1995] presented the first...... of nodes, the number of leaves, and the depth of a tree S ε {P, T}. In this article we show that the tree inclusion problem can be solved in space O(nT ) and time: Eqation Presented ∑ This improves or matches the best known time complexities while using only linear space instead of quadratic...

  11. Shapes of tree representations of spin-glass landscapes

    International Nuclear Information System (INIS)

    Much of the information about the multi-valley structure of disordered spin systems can be convened in a simple tree structure - a barrier tree - the leaves and internal nodes of which represent, respectively, the local minima and the lowest energy saddles connecting those minima. Here we apply several statistics used in the study of phylogenetic trees to barrier trees that result from the energy landscapes of p-spin models. These statistics give information about the shape of these barrier trees, in particular about balance and symmetry. We then ask if they can be used to classify different types of landscapes, compare them with results obtained from random trees, and investigate the structure of subtrees of the barrier trees. We conclude that at least one of the used statistics is capable of distinguishing different types of landscapes, that the barrier trees from p-spin energy landscapes are quite different from random trees, and that subtrees of barrier trees do not reflect the overall tree structure, but their structure is correlated with their 'depth' in the tree

  12. Tree Tectonics

    Science.gov (United States)

    Vogt, Peter R.

    2004-09-01

    Nature often replicates her processes at different scales of space and time in differing media. Here a tree-trunk cross section I am preparing for a dendrochronological display at the Battle Creek Cypress Swamp Nature Sanctuary (Calvert County, Maryland) dried and cracked in a way that replicates practically all the planform features found along the Mid-Oceanic Ridge (see Figure 1). The left-lateral offset of saw marks, contrasting with the right-lateral ``rift'' offset, even illustrates the distinction between transcurrent (strike-slip) and transform faults, the latter only recognized as a geologic feature, by J. Tuzo Wilson, in 1965. However, wood cracking is but one of many examples of natural processes that replicate one or several elements of lithospheric plate tectonics. Many of these examples occur in everyday venues and thus make great teaching aids, ``teachable'' from primary school to university levels. Plate tectonics, the dominant process of Earth geology, also occurs in miniature on the surface of some lava lakes, and as ``ice plate tectonics'' on our frozen seas and lakes. Ice tectonics also happens at larger spatial and temporal scales on the Jovian moons Europa and perhaps Ganymede. Tabletop plate tectonics, in which a molten-paraffin ``asthenosphere'' is surfaced by a skin of congealing wax ``plates,'' first replicated Mid-Oceanic Ridge type seafloor spreading more than three decades ago. A seismologist (J. Brune, personal communication, 2004) discovered wax plate tectonics by casually and serendipitously pulling a stick across a container of molten wax his wife and daughters had used in making candles. Brune and his student D. Oldenburg followed up and mirabile dictu published the results in Science (178, 301-304).

  13. Healthy,Happy trees

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Healthy trees are important to us all. Trees provide shade, beauty, and homes for wildlife. Trees give us products like paper and wood. Trees can give us all this only if they are healthy.They must be well cared for to remain healthy.

  14. TRAVEL AND HOME LEAVE

    CERN Multimedia

    Human Resources Division

    2002-01-01

    Administrative procedures for : Travel to the home station and home leave (hl) Additional travel to the home station (at) Travel to the home station and home leave for family reasons (hlf) As part of the process of simplifying administrative procedures, HR and AS Divisions have devised a new, virtually automatic procedure for payment of travel expenses to the home station. The changes are aimed at rationalising administrative procedures and not at reducing benefits. The conditions of eligibility are unchanged. The new procedure, which will be operational with effect from 1st June 2002, will greatly simplify the administrative processing of claims for travel expenses and the recording of home leaves. Currently, requests for payment are introduced manually into the Advances and Claims system (AVCL) by divisional secretariats. All travel to the home station starting prior to 1st June 2002 will be processed according to the existing system whereas that starting on 1st June and after will be processed accordi...

  15. A practical O(n log2 i>n>) time algorithm for computing the triplet distance on binary trees

    DEFF Research Database (Denmark)

    Sand, Andreas; Brodal, Gerth Stølting; Fagerberg, Rolf;

    2013-01-01

    The triplet distance is a distance measure that compares two rooted trees on the same set of leaves by enumerating all sub-sets of three leaves and counting how often the induced topologies of the tree are equal or different. We present an algorithm that computes the triplet distance between two ...

  16. Morphological variability of leaves of Sorbus torminalis (L.) Crantz in Poland

    OpenAIRE

    Leszek Bednorz

    2011-01-01

    This paper presents the results of the study on morphological variability of leaves of a scattered tree species Sorbus torminalis (L.) Crantz) in Poland. The leaves from short- and long shoots were collected from 17 localities widespread within the range of the species in Poland. Leaves were measured according to 15 morphological traits. The biometric data were subjected to multivariate statistical analysis in attempt to define variability between local populations. Most of the leaf traits ar...

  17. Effect of eucalyptus (Eucalyptus citriodora) fresh or residue leaves on methane emission in vitro

    OpenAIRE

    Adibe L. Abdalla; Mohamed E.A. Nasser; Sobhy M.A. Sallam; Ives C.S. Bueno

    2010-01-01

    Rumen fermentation and methane emission for eucalyptus (Eucalyptus citriodora) fresh leaves (FL) or residue leaves (RL), after essential oil extraction from eucalyptus leaves in comparison with alfalfa (Medicago sativa) hay, were investigated in vitro. Eucalyptus FL and RL were obtained from the Distillery Trees Barras Company, Torrinha City, Sao Paulo, Brazil. The semi-automatic system of gas production was used to measure gas production, methane emission and rumen fermentation after 24 h in...

  18. X-tree

    OpenAIRE

    Keim, Daniel A.; Bustos Cárdenas, Benjamin Eugenio; Berchtold, Stefan; Kriegel, Hans-Peter

    2008-01-01

    The X-tree (eXtended node tree) [1] is a spatial access method [2] that supports efficient query processing for high-dimensional data. It supports not only point data but also extended spatial data. The X-tree provides overlap-free split whenever it is possible without allowing the tree to degenerate; otherwise, the X-tree uses extended variable size directory nodes, so-called supernodes. The X-tree may be seen as a hybrid of a linear array-like and a hierarchical R-tree-like directory.

  19. Life-history strategies affect aphid preference for yellowing leaves.

    Science.gov (United States)

    Holopainen, Jarmo K; Semiz, Gürkan; Blande, James D

    2009-10-23

    According to the nutrient-translocation hypothesis, yellowing tree leaves are colonized by aphids at the end of the growing season owing to improved availability of nutrients in the phloem sap after chlorophyll degradation. We measured aphid densities on potted Betula pendula seedlings in a field site where a small proportion of foliage rapidly turned yellow before normal autumn coloration as a consequence of root anoxia. The number of adults and nymphs of the birch-feeding specialist aphids Euceraphis betulae, Betulaphis brevipilosa and Callipterinella tuberculata were counted from leaves on each of the 222 plants. Aphids were detected on 19 per cent of green leaves and on 41 per cent of yellow leaves. There was no indication of aphid avoidance of yellow leaves, and the number of winged (alate) viviparous E. betulae adults and their nymphs were significantly higher on yellow leaves than on green leaves, while the numbers of apterous B. brevipilosa and C. tuberculata did not differ between the leaf colour types. Our result suggests that only aphid species with alate generation during colour change can take advantage of yellowing leaves. This may explain the exceptional abundance of E. betulae compared with other aphid species on birches. PMID:19535364

  20. Biological Activity of Essential Oils from Leaves and Fruits of Pepper Tree (Schinus molle L. to Control Rice Weevil (Sitophilus oryzae L. Bioactividad de aceites esenciales de hojas y frutos del aguaribay (Schinus molle L. en el gorgojo del arroz (Sitophilus oryzae L.

    Directory of Open Access Journals (Sweden)

    Verónica Benzi

    2009-06-01

    Full Text Available Rice weevil (Sitophilus oryzae L. is a primary insect pest of stored grain. The development of resistance resulted in the application of synthetic insecticides. In recent years many plant essential oils have provided potential alternatives to currently used insect control agents. The Brazilian pepper tree (Schinus molle L. var. areira (L. DC. (Anacardiaceae has different biological properties such as insecticidal activity. In this study, repellent, fumigant activity, nutritional indices, and feeding deterrent action were evaluated on S. oryzae adults. Filter paper impregnation was used to test fumigant toxicity, whereas treated whole wheat was used to evaluate repellent activity and a flour disk bioassay was done to evaluate feeding deterrent action and nutritional index alteration. Leaf essential oils showed repellent effects at both concentrations (0.04 and 0.4% w/w, while fruit essential oils lacked repellent activity. Both plant oils altered nutritional indices. Fruit essential oils had a strong feeding deterrent action (62% while leaves had a slight effect (40.6%. With respect to fumigant activity, neither of the essential oils was found to be toxic.El gorgojo del arroz (Sitophilus oryzae. L. es un insecto-plaga de infestación primaria de granos. El uso de insecticidas sintéticos ha desarrollado fenómenos de resistencia. En los últimos años los aceites esenciales se presentan como una alternativa en el control de insectos-plaga. El aguaribay (Schinus molle L. var. areira (L. DC. (Anacardiaceae es una planta con diferentes propiedades biológicas entre las que se destacan el uso como insecticida. El objetivo de este estudio fue evaluar la actividad fumigante, repelente, los índices nutricionales y la actividad antialimentaria de los aceites esenciales de hojas y frutos de S. molle var. areira en adultos de S. oryzae. Para la actividad fumigante se utilizó la técnica de impregnación de papeles de filtro; para la actividad repelente

  1. Femtosecond Laser-Induced Breakdown Spectroscopy for Detection of Trace Elements in Sophora Leaves

    Institute of Scientific and Technical Information of China (English)

    Myriam Bossu; HAO Zuo-Qiang; Matthieu Baudelet; YU Jia; ZHANG Zhe; ZHANG Jie

    2007-01-01

    Sophora leaves from several areas in Beijing are analysed by femtoeecond laser-induced breakdown spectroscopy (femto-LIBS).AIthough the used spectral detection systemis not time-resolved,thespectral lines of trace mineral elements are detected and anallyed.It is proven that the femto-LIBS can be an effcient method to detect mineral trace elements contained in tree leaves which is a biomonitor for atmospheric pollution assessment or botanic studies.An interesting case of correlation between trace elements detected in tree leaves and the pollution of the concerned area is presented,for the first time to our knowledge.

  2. Does Leave Work?

    NARCIS (Netherlands)

    Heleen van Luijn; Saskia Keuzenkamp

    2004-01-01

    More and more people have to combine work and care responsibilities, and work part-time or use daycare and after-school care facilities to help them do so. The Work and Care Act, which came into force on 1 December 2001, combined all the existing schemes - such as parental and maternity leave - and

  3. Leaves: Nature's Solar Collectors

    Science.gov (United States)

    Isabelle, Aaron D.; de Groot, Cornelis

    2009-01-01

    One of the most captivating things about plants is the way they capture the Sun's energy, but this can be a difficult topic to cover with elementary students. Therefore, to help students to make a concrete connection to this abstract concept, this series of solar-energy lessons focuses on leaves and how they act as "solar collectors." As students…

  4. REMINDER: Saved Leave Scheme (SLS)

    CERN Multimedia

    2003-01-01

    Transfer of leave to saved leave accounts Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'* annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No 22B) can be transferred to the saved leave account at the end of the leave year (30 September). We remind you that unused leave of all those taking part in the saved leave scheme at the closure of the leave year accounts is transferred automatically to the saved leave account on that date. Therefore, staff members have no administrative steps to take. In addition, the transfer, which eliminates the risk of omitting to request leave transfers and rules out calculation errors in transfer requests, will be clearly shown in the list of leave transactions that can be consulted in EDH from October 2003 onwards. Furthermore, this automatic leave transfer optimizes staff members' chances of benefiting from a saved leave bonus provided that they ar...

  5. Which trees should be removed in thinning treatments?

    Institute of Scientific and Technical Information of China (English)

    Timo Pukkala; Erkki Lhde; Olavi Laiho

    2016-01-01

    Background:In economically optimal management, trees that are removed in a thinning treatment should be selected on the basis of their value, relative value increment and the effect of removal on the growth of remaining trees. Large valuable trees with decreased value increment should be removed, especially when they overtop smaller trees. Methods:This study optimized the tree selection rule in the thinning treatments of continuous cover management when the aim is to maximize the profitability of forest management. The weights of three criteria (stem value, relative value increment and effect of removal on the competition of remaining trees) were optimized together with thinning intervals. Results and conclusions:The results confirmed the hypothesis that optimal thinning involves removing predominantly large trees. Increasing stumpage value, decreasing relative value increment, and increasing competitive influence increased the likelihood that removal is optimal decision. However, if the spatial distribution of trees is irregular, it is optimal to leave large trees in sparse places and remove somewhat smaller trees from dense places. However, the benefit of optimal thinning, as compared to diameter limit cutting is not usually large in pure one-species stands. On the contrary, removing the smallest trees from the stand may lead to significant (30–40%) reductions in the net present value of harvest incomes.

  6. Fault tree handbook

    International Nuclear Information System (INIS)

    This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic concepts for fault tree analysis; basic elements of a fault tree; fault tree construction; probability, statistics, and Boolean algebra for the fault tree analyst; qualitative and quantitative fault tree evaluation techniques; and computer codes for fault tree evaluation. Also discussed are several example problems illustrating the basic concepts of fault tree construction and evaluation

  7. 长白山阔叶红松林中影响乔木幼苗存活的关键因素%Effects of biotic and abiotic factors on tree seedling survival in a broad-leaved Korean pine (Pinus koraiensis) mixed forest on Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    肖翠; 刘帅; 黄珍; 樊莹; 王均伟; 赵秀海; 唐景毅

    2015-01-01

    应用广义线性混合模型,对长白山阔叶红松林中影响幼苗存活的生物因素和非生物因素进行分析。结果表明:(1)在群落水平上,幼苗存活率和生物因素中同种幼苗邻居显著负相关,说明在阔叶红松林群落中存在负密度制约效应。(2)生物因子和非生物因子对不同年龄阶段的幼苗存活率影响不同。对于1年生的幼苗,幼苗存活率与异种大树邻居呈显著负相关,与同种大树邻居呈显著正相关;对于2—3年生的幼苗,其存活率和同种幼苗邻居、同种大树邻居均呈显著负相关,和非生物因子相关不显著;对于4年生以上的幼苗,其存活率和土壤主成分分析的PC1(低的有机质、速效钾、速效氮等比较贫瘠的土壤)显著负相关。(3)种子的传播方式不同,幼苗存活率的影响因子也不同。对于风传播的物种,存活率与同种幼苗邻居密度显著正相关。对于重力传播的物种,幼苗存活率与土壤PC3(高的全氮和速效氮,含氮较高的土壤)、异种大树邻居、草本密度呈负相关,与林冠开阔度和草本盖度成正相关。(4)对于不同的物种,影响幼苗存活的因素也不同。紫椴的幼苗存活率与土壤PC3、异种大树邻居、草本密度呈显著负相关,与土壤主成分PC2(高的有机质和全氮等养分比较好的土壤)呈显著正相关。%Seedling recruitment plays a key role in determining species composition and diversity. Exploring patterns of seedling dynamics can therefore provide crucial insights into the mechanisms that affect seedling recruitment. The broad-leaved Korean pine ( Pinus koraiensis) mixed forest is a temperate forest typical of northeast China. In 2007, we established a 1 hm2 plot in a broad-leaved Korean pine mixed forest on Changbai Mountain, northeast China. We identified, tagged, and mapped each tree with diameter at breast height ≥1 cm. At the same time, we set up 100

  8. Effects of biotic and abiotic factors on tree seedling survival in a broad-leaved Korean pine (Pinus koraiensis) mixed forest on Changbai Mountain%长白山阔叶红松林中影响乔木幼苗存活的关键因素

    Institute of Scientific and Technical Information of China (English)

    肖翠; 刘帅; 黄珍; 樊莹; 王均伟; 赵秀海; 唐景毅

    2015-01-01

    Seedling recruitment plays a key role in determining species composition and diversity. Exploring patterns of seedling dynamics can therefore provide crucial insights into the mechanisms that affect seedling recruitment. The broad-leaved Korean pine ( Pinus koraiensis) mixed forest is a temperate forest typical of northeast China. In 2007, we established a 1 hm2 plot in a broad-leaved Korean pine mixed forest on Changbai Mountain, northeast China. We identified, tagged, and mapped each tree with diameter at breast height ≥1 cm. At the same time, we set up 100 seedling quadrats of 1m × 1m which were censused every July. In total, we collected data on 1288 adult trees and 965 seedlings in the 1 hm2 plot between 2012 and 2013, and examined the importance of biotic and abiotic factors on seedling survival using a generalized mixed linear model. Biotic factors included presence of conspecific seedling neighbors and heterospecific seedling neighbors, presence of conspecific adult neighbors and heterospecific adult neighbors, and herb density and herb cover. Abiotic factors included soil organic matter, available soil phosphorus, available soil potassium, available soil nitrogen, total soil nitrogen, and canopy openness. Conspecific neighbors had a significant negative effect on seedling survival at the community level, indicating significant negative density-dependence effects. The effects of biotic and abiotic factors on seedlings differed with seedling age. Conspecific adult neighbors and canopy openness had significant positive effects on survival of, 1-year seedlings while heterospecific adult neighbors had a significant negative effect. In contrast, for 2- to 3-year-old seedlings, conspecific seedling neighbors and conspecific adult neighbors showed a significant negative effect on seedling survival, but abiotic factors had no significant effect. Moreover, for ≥4-year-old seedlings, soil PC axis 1 ( associated with low organic matter available K, available N

  9. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting...... tree is isomorphic to T? We prove that in the general setting, CST is NP-complete, which implies that the tree edit distance considered here is also NP-hard, even when both input trees having diameters bounded by 10. We also show that, when the number of distinct stars is bounded by a constant k, CTS...

  10. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting...... tree is isomorphic to T? We prove that in the general setting, CST is NP-complete, which implies that the tree edit distance considered here is also NP-hard, even when both input trees having diameters bounded by 10. We also show that, when the number of distinct stars is bounded by a constant k, CTS...

  11. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

    Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

  12. Error Probability Bounds for M-ary Relay Trees

    CERN Document Server

    Zhang, Zhenliang; Pezeshki, Ali; Moran, William; Howard, Stephen D

    2012-01-01

    We study the detection error probabilities associated with an M-ary relay tree, where the leaves of the tree correspond to identical and independent sensors. Only these leaves are sensors. The root of the tree represents a fusion center that makes the overall detection decision. Each of the other nodes in the tree is a relay node that combines M summarized messages from its immediate child nodes to form a single output message using the majority dominance rule. We derive tight upper and lower bounds for the Type I and II error probabilities at the fusion center as explicit functions of the number of sensors in the case of binary message alphabets. These bounds characterize how fast the error probabilities converge to 0 with respect to the number of sensors.

  13. Error Probability Bounds for Balanced Binary Relay Trees

    CERN Document Server

    Zhang, Zhenliang; Moran, William; Howard, Stephen D; Chong, Edwin K P

    2011-01-01

    We study the detection error probability associated with a balanced binary relay tree, where the leaves of the tree correspond to $N$ identical and independent detectors. The root of the tree represents a fusion center that makes the overall detection decision. Each of the other nodes in the tree are relay nodes that combine two binary messages to form a single output binary message. In this way, the information from the detectors is aggregated into the fusion center via the intermediate relay nodes. In this context, we describe the evolution of Type I and Type II error probabilities of the binary data as it propagates from the leaves towards the root. Tight upper and lower bounds for the total error probability at the fusion center as functions of $N$ are derived. These characterize how fast the total error probability converges to 0 with respect to $N$, even if the individual sensors have error probabilities that converge to 1/2.

  14. Horton Law in Self-Similar Trees

    Science.gov (United States)

    Kovchegov, Yevgeniy; Zaliapin, Ilya

    2016-04-01

    Self-similarity of random trees is related to the operation of pruning. Pruning ℛ cuts the leaves and their parental edges and removes the resulting chains of degree-two nodes from a finite tree. A Horton-Strahler order of a vertex v and its parental edge is defined as the minimal number of prunings necessary to eliminate the subtree rooted at v. A branch is a group of neighboring vertices and edges of the same order. The Horton numbers 𝒩k[K] and 𝒩ij[K] are defined as the expected number of branches of order k, and the expected number of order-i branches that merged order-j branches, j > i, respectively, in a finite tree of order K. The Tokunaga coefficients are defined as Tij[K] = 𝒩ij[K]/𝒩j[K]. The pruning decreases the orders of tree vertices by unity. A rooted full binary tree is said to be mean-self-similar if its Tokunaga coefficients are invariant with respect to pruning: Tk := Ti,i+k[K]. We show that for self-similar trees, the condition limsupk→∞Tk1/k 0 and every k ≥ 1. This work is a step toward providing rigorous foundations for the Horton law that, being omnipresent in natural branching systems, has escaped so far a formal explanation.

  15. 增补UV-B辐射下南亚热带森林建群树种叶片对UV-B辐射的防护%UV-B Screening in Leaves of Constructive Tree Species of Low Subtropical Forest under Supplementary UV-B Radiation

    Institute of Scientific and Technical Information of China (English)

    赵平; 孙谷畴; 曾小平

    2008-01-01

    of UV-B radiation absorbing materials, forming a functional protecting screen against UV-B radiation. However, Schima superba and Castanopsi fissa that contained relatively high alkali-extractable cell wall-bound phendics under natural sunlight exhibited a decrease in content of these compounds when exposed to supplementary UV-B radiation, suggesting that under supplementary UV-B radiation the cell wall-phendics in epidermal cell layers might be transformed into soluble compounds in vacuoles where there were lower contents of methanol soluble pigment. This fact assumes that a strategy for protection of photosynthetic apparatus hidden in mesophyll tissue was evolved. Chlorophyll a+b content (μg g-1) was not affected in the needles of P. massoniana and a decrease of 10.7% to 16.8% (mg m-1) occurred in the leaves of the other examined broad-leaved tree species under exposure of supplementary UV-B radiation. Response of carotenoids to supplementary UV-B radiation was variable: The decreased level of carotenoid was observed in C. hystrix and S. superba, and carotenoids were stimulated in P. massoniana, C. chinensis and C. fissa, which might be a functional increase in dissipation of excited energy. The results showed that different acclimation strategies were developed to protect against the increasing UV-B radiation in nature and flavoid screen in the acclimation to UV-B radiation was an important feature of adaptation process in the plants of low subtropical forest. Tab 4, Ref 29

  16. Using FEM to predict tree motion in a wind field

    Institute of Scientific and Technical Information of China (English)

    Xiao-yi HU; Wei-ming TAO; Yi-mu GUO

    2008-01-01

    In this paper we propose a finite element (FE) simulation method to predict tree motion in a wind field. Two FE tree models were investigated: One model was generated based on a realistic nature-looking geometric tree model, and the other was a symmetric model to investigate the influence of asymmetric material properties on tree motion. The vortex-induced vibration (VIV) theory is introduced to estimate the fluctuating wind force being exerted on tree stems and the fluid-structure interaction (FSI) analysis is also included in the simulation. The results indicate that asymmetric material properties result in the crosswind displacement of the investigated node and the main swaying direction deviation. The simulation reveals that under wind loading, a tree with leaves has much larger swaying amplitude along the wind direction and longer swaying period than a tree without leaves.However, the crosswind swaying amplitude is mainly due to branch interaction. The numerical simulation proved that the interaction of tree branches can prevent dangerous swaying motion developing.

  17. Examining growth, yield and bean quality of Ethiopian coffee trees

    OpenAIRE

    Bote, Adugna

    2016-01-01

    Coffee (Coffeaarabica L.)bean production and quality are determined by a diversity of interacting factors (e.g. shade, nitrogen, crop traits). Bean yield increases with increase in radiation, but adequate fertilizer suppliesare needed to sustain the productivity. This thesis analysed coffee tree growth, bean production and bean quality in relation to different degrees of exposure to radiation and nitrogen supply. Growth of leaves and branches and properties of leaves such as specific leaf are...

  18. Comparative Characterization of Total Flavonol Glycosides and Terpene Lactones at Different Ages, from Different Cultivation Sources and Genders of Ginkgo biloba Leaves

    Directory of Open Access Journals (Sweden)

    Yong Qin

    2012-08-01

    Full Text Available The extract from Ginkgo biloba leaves has become a very popular plant medicine and herbal supplement for its potential benefit in alleviating symptoms associated with peripheral vascular disease, dementia, asthma and tinnitus. Most research on G. biloba leaves focus on the leaves collected in July and August from four to seven year-old trees, however a large number of leaves from fruit cultivars (trees older than 10 years are ignored and become obsolete after fruit harvest season (November. In this paper, we expand the tree age range (from one to 300 years and first comparatively analyze the total flavonol glycosides and terpene lactones at different ages, from different cultivation sources and genders of G. biloba leaves collected in November by using the validated HPLC-ELSD and HPLC-PDA methods. The results show that the contents of total terpene lactones and flavonol glycosides in the leaves of young ginkgo trees are higher than those in old trees, and they are higher in male trees than in female trees. Geographical factors appear to have a significant influence on the contents as well. These results will provide a good basis for the comprehensive utilization of G. biloba leaves, especially the leaves from fruit cultivars.

  19. The results of fluorescence spectrums of oak and birch leaves investigation from the 30-km influenced zone of Chernobyl NPP

    International Nuclear Information System (INIS)

    The results of a long-term research of laser induced fluorescence of foliage tree' leaves (oak, birch) that grow in different conditions of radioactive pollution (30-km zone of Chernobyl NPP) are presented

  20. Uniform random spanning trees

    OpenAIRE

    Pemantle, Robin

    2004-01-01

    There are several good reasons you might want to read about uniform spanning trees, one being that spanning trees are useful combinatorial objects. Not only are they fundamental in algebraic graph theory and combinatorial geometry, but they predate both of these subjects, having been used by Kirchoff in the study of resistor networks. This article addresses the question about spanning trees most natural to anyone in probability theory, namely what does a typical spanning tree look like?

  1. Coded Splitting Tree Protocols

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

    2013-01-01

    This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... as possible. Evaluations show that the proposed protocol provides considerable gains over the standard tree splitting protocol applying SIC. The improvement comes at the expense of an increased feedback and receiver complexity....

  2. Interactive tree of life (iTOL) v3: an online tool for the display and annotation of phylogenetic and other trees

    OpenAIRE

    Letunic, I.; Bork, P.

    2016-01-01

    Interactive Tree Of Life (http://itol.embl.de) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. It is freely available and open to everyone. The current version was completely redesigned and rewritten, utilizing current web technologies for speedy and streamlined processing. Numerous new features were introduced and several new data types are now supported. Trees with up to 100,000 leaves can now be efficiently displayed. Full interactive control over pr...

  3. Negotiating leave in the workplace

    DEFF Research Database (Denmark)

    Bloksgaard, Lotte

    2014-01-01

    In Denmark leave entitlement is not only regulated by law but is also part of the various collective agreements established in the respective occupational sectors and at the local workplace level. Consequently, Danish fathers have very different leave entitlements, depending on the sector, branch...... men’s negotiations of parental leave at work place level and secondly, to explore and discuss how Danish fathers construct leave practices – and individual male identities – in the workplace....

  4. Winter Birch Trees

    Science.gov (United States)

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    Trees are great inspiration for artists. Many art teachers find themselves inspired and maybe somewhat obsessed with the natural beauty and elegance of the lofty tree, and how it changes through the seasons. One such tree that grows in several regions and always looks magnificent, regardless of the time of year, is the birch. In this article, the…

  5. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  6. The Wish Tree Project

    Science.gov (United States)

    Brooks, Sarah DeWitt

    2010-01-01

    This article describes the author's experience in implementing a Wish Tree project in her school in an effort to bring the school community together with a positive art-making experience during a potentially stressful time. The concept of a wish tree is simple: plant a tree; provide tags and pencils for writing wishes; and encourage everyone to…

  7. Saved Leave Scheme (SLS) : Simplified procedure for the transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2001-01-01

    As part of the process of streamlining procedures, the HR and AS Divisions have jointly developed a system whereby annual and compensatory leave will henceforth be automatically transferred1) to saved leave accounts. Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'2) annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No. 22 B) can be transferred to the saved leave account at the end of the leave year (30 September). Previously, every person taking part in the scheme has been individually issued with a form for the purposes of requesting the transfer of leave to the leave account and the transfer has then had to be done manually by HR Division. To streamline the procedure, unused leave of all those taking part in the saved leave scheme at the closure of of the leave-year accounts will henceforth be transferred automatically to the saved leave account on that date. This simplification is in the ...

  8. REMINDER Saved Leave Scheme (SLS) : Transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2002-01-01

    Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'*) annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No. 22B) can be transferred to the saved leave account at the end of the leave year (30 September). We remind you that, since last year, unused leave of all those taking part in the saved leave scheme at the closure of the leave-year accounts is transferred automatically to the saved leave account on that date. Therefore, staff members have no administrative steps to take. In addition, the transfer, which eliminates the risk of omitting to request leave transfers and rules out calculation errors in transfer requests, will be clearly shown in the list of leave transactions that can be consulted in EDH from October 2002 onwards. Furthermore, this automatic leave transfer optimizes staff members' chances of benefiting from a saved leave bonus provided that they are still participants in the schem...

  9. Composition of the essential oil from the leaves of tree domestic varieties and one wild variety of the guava plant (Psidium guajava L., Myrtaceae Avaliação dos constituintes dos óleos essenciais de folhas de goiabeira (Psidium guajava L., Myrtaceae de três cultivares e da planta silvestre

    Directory of Open Access Journals (Sweden)

    Rafaela Karin de Lima

    2010-03-01

    Full Text Available The compositions of the essential oils from the leaves of three domestic varieties of the guava tree Psidium guajava L. (Paluma, Século XXI and Pedro Sato and of one wild variety were compared. Essential oils were extracted by steam distillation, the components were identified by gas chromatography coupled to mass spectrometry GC-MS, and the apparent concentrations were determined by gas chromatography with a flame ionization detector. The results demonstrated that the three essential oils contained many common substances with a prevalence of 1,8-cineole, whereas the essential oil of the Paluma variety contained 1,8-cineole (42.68% as the major constituent, as well as α-terpineol (38.68%. The principal components of the essential oil of the Século XXI variety were 1,8-cineole (18.83%, trans-caryophyllene (12.08%, and selin-11-en-4-αol (20.98%, while those of the Pedro Sato variety and of the wild plant were 1,8-cineole (17.68% and (12.83%, caryophyllene oxide (9.34% and (9.09%, and selin-11-en-4-α-ol (21.46% and (22.19%, respectively.Os óleos essenciais de folhas de goiabeira Psidium guajava L. de três diferentes cultivares (Paluma, Século XXI e Pedro Sato e da planta silvestre foram analisados a fim de comparar os seus constituintes. O óleo essencial foi obtido por hidrodestilação em aparelho de Clevenger modificado. Para a caracterização e quantificação dos compostos presentes por CG-EM e CG respectivamente. Os resultados mostraram que os três óleos essenciais analisados apresentam inúmeras substâncias em comum com a predominância do 1,8-cineol. O óleo essencial da cultivar Paluma se difere dos demais devido a alta concentração de 1,8-cineol (42,68% e do α-terpineol (38,68%. No óleo essencial da cultivar Século XXI observase a presença do 1,8 cineol (18,83%, trans-carifileno (12,08% e o selin-11-en-4-α-ol (20,98% como majoritários, enquanto que a cultivar Pedro Sato e a planta silvestre apresentaram com o 1

  10. Effects of biotic neighbors and habitat heterogeneity on tree seedling survival in a secondary mixed conifer and broad-leaved forest in Changbai Mountain%长白山次生针阔混交林乔木幼苗存活的影响因素分析

    Institute of Scientific and Technical Information of China (English)

    刘帅; 廖嘉星; 肖翠; 范秀华

    2016-01-01

    基于长白山次生针阔混交林样地,以520个1 m ×1 m幼苗样方中胸径小于1 cm的乔木幼苗为研究对象,选取2013年和2014年的幼苗调查数据,运用广义线性混合模型(GLMM)分析了生物邻体和生境异质性对幼苗存活的影响,探讨了次生针阔混交林幼苗存活影响因素及物种共存机制。结果表明:(1)适宜大树生长的局域生境同样也适宜幼苗的存活,幼苗存活率与土壤含水量和有效氮等土壤养分显著正相关。(2)幼苗个体之间存在明显的竞争,较多的幼苗邻体显著降低幼苗的存活率。同种大树邻体和同种幼苗邻体与幼苗存活显著负相关,表明存在负密度制约效应。(3)随着幼苗年龄的增加,生境异质性对幼苗存活的影响逐渐增大。该研究证实了密度制约效应和生境异质性对幼苗存活有着重要影响,其相对重要性随着幼苗年龄级、功能群以及物种种类而变化。%Aims Our study aimed to understand the effects and the relative importance of biotic neighborhood and habitat heterogeneity for tree seedling survival in a secondary mixed conifer and broad-leaved forest in Changbai Moun-tain, north-eastern China. Methods The generalized mixed linear model was used to examine the relative effects of biotic neighborhood and habitat heterogeneity on seedling survival over two years. Important findingsOur results showed that both biotic neighborhood and habitat heterogeneity had significant effects on the seedling survival at community level. The local environment suitable for the adult growth was also suitable for seedling survival. The soil moisture and soil available nitrogen exhibited significant positive effects on seedling survival. On the other hand, seedling density had significant negative effects on seedling survival due to the individual competition. Particularly, we found significant negative density-dependent effects on seedling sur-vival which was caused by

  11. Carbon, cesium and iodine isotopes in Japanese cedar leaves from Iwaki, Fukushima

    DEFF Research Database (Denmark)

    Xu, Sheng; Cook, Gordon T.; Cresswell, Alan J.;

    2016-01-01

    Japanese cedar leaves from Iwaki, Fukushima were analyzed for carbon, cesium and iodine isotopic compositions before and after the 2011 nuclear accident. The Δ14C values reflect ambient atmospheric 14C concentrations during the year the leaves were sampled/defoliated, and also previous year......(s). The elevated 129I and 134,137Cs concentrations are attributed to direct exposure to the radioactive fallout for the pre-fallout-expended leaves and to internal translocation from older parts of the tree for post-fallout-expended leaves. 134Cs/137Cs and 129I/137Cs activity ratios suggest insignificant isotopic...

  12. Effects of pedunculate oak tree vitality on gypsy moth preference and performance

    Directory of Open Access Journals (Sweden)

    Milanović Slobodan

    2014-01-01

    Full Text Available Gypsy moths and powdery mildew play a significant role in oak decline processes. However, information is lacking on the effects on the gypsy moth of impaired tree vitality caused by defoliation or parasite infection. We assessed how pedunculate oak leaves collected from vigorous, declining, and infected trees influenced gypsy moth preference and performance (growth and nutritional indices. We found a negative effect of powdery mildew-infected leaves on gypsy moth performance, while declining trees had positive effects on gypsy moth performance and preference. All examined parameters of larvae fed declining oak leaves were higher than those of larvae fed vigorous oak leaves. Increased growth on declining oak leaves was caused by both higher consumption and more efficient food utilization. The results of this research could help us to better understand multitrophic interactions in complex communities such as oak forests. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

  13. Bioclimate and reproductive potential at the cold limit of European deciduous tree species

    OpenAIRE

    Kollas, Chris

    2013-01-01

    This thesis assessed factors that contribute to the explantion of the upper elevational and latitudinal limits of European broad-leaved tree species by using a set of ecological analysis, including in situ temperature measurements, a transplant experiment and a survey of the reproductive cycle and demography at the species limits. The following key questions were answered in five chapters: Do the elevational thermal limits of broad-leaved tree species correspond to their latitudinal t...

  14. Distributed Contour Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther H.

    2014-03-31

    Topological techniques provide robust tools for data analysis. They are used, for example, for feature extraction, for data de-noising, and for comparison of data sets. This chapter concerns contour trees, a topological descriptor that records the connectivity of the isosurfaces of scalar functions. These trees are fundamental to analysis and visualization of physical phenomena modeled by real-valued measurements. We study the parallel analysis of contour trees. After describing a particular representation of a contour tree, called local{global representation, we illustrate how di erent problems that rely on contour trees can be solved in parallel with minimal communication.

  15. Trees in Lhasa

    Institute of Scientific and Technical Information of China (English)

    Degyi

    2008-01-01

    Trees are flourishing in Lhasa wherever the history exists. There is such a man. He has already been through cus-toms after his annual trek to Lhasa, which he has been doing for over twenty years in succession to visit his tree.Although he has been making this journey for so long,it is neither to visit friends or family,nor is it his hometown.It is a tree that is tied so profoundly to his heart.When the wind blows fiercely on the bare tree and winter snow falls,he stands be-fore the tree with tears of jo...

  16. Maximum Leaf Spanning Trees of Growing Sierpinski Networks Models

    CERN Document Server

    Yao, Bing; Xu, Jin

    2016-01-01

    The dynamical phenomena of complex networks are very difficult to predict from local information due to the rich microstructures and corresponding complex dynamics. On the other hands, it is a horrible job to compute some stochastic parameters of a large network having thousand and thousand nodes. We design several recursive algorithms for finding spanning trees having maximal leaves (MLS-trees) in investigation of topological structures of Sierpinski growing network models, and use MLS-trees to determine the kernels, dominating and balanced sets of the models. We propose a new stochastic method for the models, called the edge-cumulative distribution, and show that it obeys a power law distribution.

  17. Life-history strategies affect aphid preference for yellowing leaves

    OpenAIRE

    Holopainen, Jarmo K.; Semiz, Gürkan; Blande, James D

    2009-01-01

    According to the nutrient-translocation hypothesis, yellowing tree leaves are colonized by aphids at the end of the growing season owing to improved availability of nutrients in the phloem sap after chlorophyll degradation. We measured aphid densities on potted Betula pendula seedlings in a field site where a small proportion of foliage rapidly turned yellow before normal autumn coloration as a consequence of root anoxia. The number of adults and nymphs of the birch-feeding specialist aphids ...

  18. MEMORY ENHANCING ACTIVITIES OF FICUS RELIGIOSA LEAVES IN RODENTS

    OpenAIRE

    Wangkhem Bandana Devi; Sengottuvelu S.; Haja Shrief S.; Lalitha V; Sivakumar T.

    2011-01-01

    Ficus religiosa, a sacred tree to both Hindus and Buddhists, is recognized for its medicinal as well as religious purposes in India. The ethanolic extract prepared from the leaves of Ficus religiosa was studied for memory enhancing activities in Wistar albino rats and Swiss albino mice. The present study was carried out on five models such as Elevated-Plus Maze, Step through passive avoidance test, Sodium nitrite intoxication, Hebb-Williams Maze and Radial Arm Maze to evaluate learning and me...

  19. Growth of a Pine Tree

    Science.gov (United States)

    Rollinson, Susan Wells

    2012-01-01

    The growth of a pine tree is examined by preparing "tree cookies" (cross-sectional disks) between whorls of branches. The use of Christmas trees allows the tree cookies to be obtained with inexpensive, commonly available tools. Students use the tree cookies to investigate the annual growth of the tree and how it corresponds to the number of whorls…

  20. Negotiating leave in the workplace

    DEFF Research Database (Denmark)

    Bloksgaard, Lotte

    In Denmark leave entitlement is not only regulated by law but is also part of the various collective agreements established in the respective occupational sectors and at the local workplace level. Consequently, Danish fathers have very different leave entitlements, depending on the sector, branch...... and workplace in which they are employed. The paper focuses on fathers’ negotiations of parental leave in three large Danish work places, offering men different opportunities for leave. With a focus on the differences in the work place contexts/opportunities for leave, the aim of the paper is firstly to explore...... men’s negotiations of parental leave at work place level and secondly, to explore and discuss how Danish fathers construct leave practices – and individual male identities – in the workplace....

  1. Freezing injury in potato leaves.

    Science.gov (United States)

    Sukumaran, N P; Weiser, C J

    1972-11-01

    Time-temperature profiles of freezing leaves from frost-resistant (Solanum acaule Bitt.) and frost-susceptible (Solanum tuberosum L. subsp. tuberosum Hawkes) types of potatoes did not reveal any major differences. The pattern of change in resistance of leaves to low voltage, low frequency current during freezing was different in the frost-resistant and susceptible leaves. In tissue sections from both types of leaves, cells freeze extracellularly at cooling velocities lower than 5 C per minute. Cells from leaves of resistant plants showed a higher osmotic pressure but not a higher water permeability than those from susceptible plants. The extent of injury caused by even very slow freezing was greater than that caused by equivalent isopiestic desiccation, particularly in susceptible leaves. The higher osmotic pressure in cells of leaves from resistant plants can account for the greater desiccation resistance but not for the frost resistance observed. PMID:16658217

  2. Making the National Adaptation Programme of Action (NAPA) More Responsive to the Livelihood Needs of Tree Planting Farmers, Drawing on Previous Experience in Dryland Sudan

    OpenAIRE

    Markku Kanninen; Olavi Luukkanen; Fobissie Blese Kalame

    2011-01-01

    Recently, tree planting has become popular under NAPA. For decades, many tree planting projects were implemented to reduce the vulnerability of ecosystems and societies. Despite all of these, tree-dependent livelihoods remain vulnerable, which leaves doubt on the benefit of tree planting to enhance the resilience of livelihoods to climatic shocks. This suggests that much can be learned from the past to improve future tree planting adaptation projects. This paper draws on the experience of far...

  3. From gene trees to species trees II: Species tree inference in the deep coalescence model

    OpenAIRE

    Zhang, Louxin

    2010-01-01

    When gene copies are sampled from various species, the resulting gene tree might disagree with the containing species tree. The primary causes of gene tree and species tree discord include lineage sorting, horizontal gene transfer, and gene duplication and loss. Each of these events yields a different parsimony criterion for inferring the (containing) species tree from gene trees. With lineage sorting, species tree inference is to find the tree minimizing extra gene lineages that had to coexi...

  4. Quantitative Analysis of Tree Species Diversity in Different Oak (Quercus spp.) Dominated Forests in Garhwal Himalaya, India

    OpenAIRE

    Gajendra SINGH; Gopal S. RAWAT

    2012-01-01

    Himalayan broad-leaved forests are mainly dominated by oak (Quercus spp.) species. Oak species with other tree species provide numerous ecosystem services and serve as lifeline for local inhabitants. Overall tree diversity and their status in different oak dominated forests viz., Quercus leucotrichophora (1500-2200 m), Q. floribunda (2201-2700 m) and Q. semecarpifolia (2701-3300 m) were studied in Garhwal, Himalaya. A total of 54 tree species (40 genera) in Q. leucotrichophora, 43 tree specie...

  5. Detection of heavy metals in leaves of melia azedarach and eucalyptus citriodora as biomonitring tools in the region of Quetta valley

    International Nuclear Information System (INIS)

    The concentrations of heavy metals viz., Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in leaves of two tree species, Melia azedarach and Eucalyptus citriodora (Safeda) from different sampling sites at urban areas in Quetta city , were measured. Correlation between elements and the use of tree leaves as indicators of environmental pollution was investigated. The results show that the higher concentrations of heavy metals in Eucalyptus leaves of the areas of the Hudda, Barori and Mashraqi by Pass and in the areas with dense transportation activities are in function. So this preliminary study presents scientific basis to establish the applicability of the tree leaves as bio-monitoring tool for the rapid evaluation of the pollution status in the Quetta city by analyzing heavy metals concentration in the tree leaves. (author)

  6. Slower phloem transport in gymnosperm trees can be attributed to higher sieve element resistance

    DEFF Research Database (Denmark)

    Liesche, Johannes; Windt, Carel; Bohr, Tomas;

    2015-01-01

    In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Angiosperm and gymnosperm trees have a fundamentally different phloem anatomy with respect to cell size, sha...

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

    Science.gov (United States)

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

  8. A sub-cubic time algorithm for computing the quartet distance between two general trees

    DEFF Research Database (Denmark)

    Nielsen, Jesper; Kristensen, Anders Kabell; Mailund, Thomas;

    2011-01-01

    derived a new algorithm for computing the quartet distance between a pair of general trees, i.e. trees where inner nodes can have any degree ≥ 3. The time and space complexity of our algorithm is sub-cubic in the number of leaves and does not depend on the degree of the inner nodes. This makes...

  9. Further analysis on the total number of subtrees of trees

    CERN Document Server

    Li, Shuchao

    2012-01-01

    We study that over some types of trees with a given number of vertices, which trees minimize or maximize the total number of subtrees. Trees minimizing (resp. maximizing) the total number of subtrees usually maximize (resp. minimize) the Wiener index, and vice versa. Here are some of our results: (1) Let $\\mathscr{T}_n^k$ be the set of all $n$-vertex trees with $k$ leaves, we determine the maximum (resp. minimum) value of the total number of subtrees of trees among $\\mathscr{T}_n^k$ and characterize the extremal graphs. (2) Let $\\mathscr{P}_n^{p,q}$ be the set of all $n$-vertex trees, each of which has a $(p,q)$-bipartition, we determine the maximum (resp. minimum) value of the total number of subtrees of trees among $\\mathscr{P}_n^{p,q}$ and characterize the extremal graphs. (3) Let $\\mathscr{A}_n^q$ be the set of all $q$-ary trees with $n$ non-leaf vertices, we determine the minimum value of the total number of subtrees of trees among $\\mathscr{A}_n^q$ and identify the extremal graph.

  10. A Beta-splitting model for evolutionary trees.

    Science.gov (United States)

    Sainudiin, Raazesh; Véber, Amandine

    2016-05-01

    In this article, we construct a generalization of the Blum-François Beta-splitting model for evolutionary trees, which was itself inspired by Aldous' Beta-splitting model on cladograms. The novelty of our approach allows for asymmetric shares of diversification rates (or diversification 'potential') between two sister species in an evolutionarily interpretable manner, as well as the addition of extinction to the model in a natural way. We describe the incremental evolutionary construction of a tree with n leaves by splitting or freezing extant lineages through the generating, organizing and deleting processes. We then give the probability of any (binary rooted) tree under this model with no extinction, at several resolutions: ranked planar trees giving asymmetric roles to the first and second offspring species of a given species and keeping track of the order of the speciation events occurring during the creation of the tree, unranked planar trees, ranked non-planar trees and finally (unranked non-planar) trees. We also describe a continuous-time equivalent of the generating, organizing and deleting processes where tree topology and branch lengths are jointly modelled and provide code in SageMath/Python for these algorithms. PMID:27293780

  11. Yule-generated trees constrained by node imbalance.

    Science.gov (United States)

    Disanto, Filippo; Schlizio, Anna; Wiehe, Thomas

    2013-11-01

    The Yule process generates a class of binary trees which is fundamental to population genetic models and other applications in evolutionary biology. In this paper, we introduce a family of sub-classes of ranked trees, called Ω-trees, which are characterized by imbalance of internal nodes. The degree of imbalance is defined by an integer 0 ≤ ω. For caterpillars, the extreme case of unbalanced trees, ω = 0. Under models of neutral evolution, for instance the Yule model, trees with small ω are unlikely to occur by chance. Indeed, imbalance can be a signature of permanent selection pressure, such as observable in the genealogies of certain pathogens. From a mathematical point of view it is interesting to observe that the space of Ω-trees maintains several statistical invariants although it is drastically reduced in size compared to the space of unconstrained Yule trees. Using generating functions, we study here some basic combinatorial properties of Ω-trees. We focus on the distribution of the number of subtrees with two leaves. We show that expectation and variance of this distribution match those for unconstrained trees already for very small values of ω.

  12. A Beta-splitting model for evolutionary trees

    Science.gov (United States)

    Sainudiin, Raazesh

    2016-01-01

    In this article, we construct a generalization of the Blum–François Beta-splitting model for evolutionary trees, which was itself inspired by Aldous' Beta-splitting model on cladograms. The novelty of our approach allows for asymmetric shares of diversification rates (or diversification ‘potential’) between two sister species in an evolutionarily interpretable manner, as well as the addition of extinction to the model in a natural way. We describe the incremental evolutionary construction of a tree with n leaves by splitting or freezing extant lineages through the generating, organizing and deleting processes. We then give the probability of any (binary rooted) tree under this model with no extinction, at several resolutions: ranked planar trees giving asymmetric roles to the first and second offspring species of a given species and keeping track of the order of the speciation events occurring during the creation of the tree, unranked planar trees, ranked non-planar trees and finally (unranked non-planar) trees. We also describe a continuous-time equivalent of the generating, organizing and deleting processes where tree topology and branch lengths are jointly modelled and provide code in SageMath/Python for these algorithms. PMID:27293780

  13. Green leaves as indicator for air pollution

    International Nuclear Information System (INIS)

    Green leaves of Ficus (Ficus penegalensis) and Neem (Azadirachta indica) were analyzed for their trace metals (Pb, Zn and Cd) contents. The samples were collected and washed according to metal analysis standardization. Solutions of the samples for analysis were obtained by wet-digestion method using nitric perchloric acid mixture. The trace elements lead, zinc and cadmium were determined by Atomic Absorption Spectroscopic technique (AAS) for the 18 samples collected from Khartoum (Sharia elneel), Omdurman (Ombadda) and Khartoum North (Kadaro) as heavy-traffic, low-traffic areas and distal area, respectively. The species Ficus and Neem samples were collected each randomly from such areas. The samples were taken from the tips, mids and bottoms of each tree. (Author)

  14. Flavonoids from leaves of Mauritia flexuosa

    Directory of Open Access Journals (Sweden)

    Djalma M. de Oliveira

    2013-08-01

    Full Text Available The chromatographic fractionation of the Mauritia flexuosa L. f., Arecaceae, leaves extract, a plant known by the name of buriti palm tree, resulted in the isolation of six flavonoids: tricin-7-O-rutinoside, apigenin-6-C-arabinoside, 8-C-glucoside (isoschaftoside, kaempferol-3-O-rutinoside (nicotiflorine, quercetin-3-O-rutinoside (rutin, luteolin-8-C-glucoside (orientin and luteolin-6-C-glucoside (isoorientin. The flavonoids were found out and previously reported as constituents of the Arecaceae family plants, but the occurrence of C-glucoside flavonoids, in the species being analyzed, is described for the first time on this study. The structural elucidations of all of the isolated compounds were performed by means of the comparison of their spectral data (¹H and 13C NMR, UV and ESI-MS with those ones of the literature.

  15. Water isotopologues in leaves

    Science.gov (United States)

    Cuntz, M.; Ogée, J.; Farquhar, G. D.; Cernusak, L. A.; Peylin, P.; Bariac, T.

    2007-12-01

    Leaf water isotope enrichment is a cornerstone of a variety of isotopic applications. It imprints on different substances such as atmospheric CO2, O2, and plant organic matter. But different applications use enrichment in different parts of the leaf and weighted by different fluxes. For example, leaf organic matter is determined by the assimilation-weighted average bulk water enrichment. Atmospheric CO2 and O2 are determined by the enrichment near the evaporating sites, either weighted by the one-way CO2 flux from the stomata to the atmosphere or by electron transport, resp. These applications of leaf water enrichment are used from the leaf level up to global scales. It is therefore essential to understand the time course of leaf water enrichment at both the evaporating sites and in the mesophyll but also to asses the suitability of simple models such as the Craig & Gordon (1965) steady-state prediction or the Dongmann et al. (1974) non-steady-state model. We describe here advection and diffusion of water isotopologues in leaves in the non-steady state. We first show how this relates to earlier non-steady state bulk leaf water enrichment models. The adv.-diff. model compares very well with observations of bulk mesophyll water during the whole diel cycle. It compares well with the enrichment at the evaporative sites during the day but shows some deviations at night. It is clear that night-time stomatal conductance should be measured in the future. However, varying mesophyll water volume did not seem critical for a good prediction. In addition, observations of single diurnal cycles do not constrain the effective length in the mesophyll. Finally, we show when simpler models of leaf water enrichment are suitable for applications of leaf water isotopes once weighted with the appropriate gas exchange flux. We then present a two-dimensional adv.-diff. description of leaf water enrichment along monocot leaves. The model reproduces well all published measurements along

  16. Multiscale model of a freeze-thaw process for tree sap exudation

    OpenAIRE

    Graf, Isabell; Ceseri, Maurizio; Stockie, John M.

    2015-01-01

    Sap transport in trees has long fascinated scientists, and a vast literature exists on experimental and modelling studies of trees during the growing season when large negative stem pressures are generated by transpiration from leaves. Much less attention has been paid to winter months when trees are largely dormant but nonetheless continue to exhibit interesting flow behaviour. A prime example is sap exudation, which refers to the peculiar ability of sugar maple (Acer saccharum) and related ...

  17. A Quadratic Time Algorithm for Computing the Quartet Distance between Two General Trees

    DEFF Research Database (Denmark)

    Mailund, Thomas; Nielsen, Jesper; Pedersen, Christian Storm

    2009-01-01

    We derive a quadratic time and space algorithm for computing the quartet distance between a pair of general trees, i.e. trees where inner nodes can have any degreeges3. The time and space complexity of our algorithm is quadratic in the number of leaves and does not depend on the degree of the inner...... nodes. This makes it the fastest algorithm for computing the quartet distance between general trees independent of the degree of the inner nodes....

  18. Electrical signaling, stomatal conductance, ABA and Ethylene content in avocado trees in response to root hypoxia

    OpenAIRE

    Pilar M Gil; Gurovich, Luis; Schaffer, Bruce; García, Nicolás; Iturriaga, Rodrigo

    2009-01-01

    Avocado (Persea americana Mill.) trees are among the most sensitive of fruit tree species to root hypoxia as a result of flooded or poorly drained soil. Similar to drought stress, an early physiological response to root hypoxia in avocado is a reduction of stomatal conductance. It has been previously determined in avocado trees that an extracellular electrical signal between the base of stem and leaves is produced and related to reductions in stomatal conductance in response to drought stress...

  19. How does tree age influence damage and recovery in forests impacted by freezing rain and snow?

    Science.gov (United States)

    Zhu, LiRong; Zhou, Ting; Chen, BaoMing; Peng, ShaoLin

    2015-05-01

    The response and recovery mechanisms of forests to damage from freezing rain and snow events are a key topic in forest research and management. However, the relationship between the degree of damage and tree age, i.e., whether seedlings, young trees, or adult trees are most vulnerable, remains unclear and is rarely reported. We investigated the effect of tree age on the degrees of vegetation damage and subsequent recovery in three subtropical forest types-coniferous, mixed, and broad-leaved-in the Tianjing Mountains, South China, after a series of rare icy rain and freezing snow events in 2008. The results showed that damage and recovery rates were both dependent on tree age, with the proportion of damaged vegetation increasing with age (estimated by diameter at breast height, DBH) in all three forest types and gradually plateauing. Significant variation occurred among forest types. Young trees in the coniferous forest were more vulnerable than those in the broad-leaved forest. The type of damage also varied with tree age in different ways in the three forest types. The proportion of young seedlings that were uprooted (the most severe type of damage) was highest in the coniferous forest. In the mixed forest, young trees were significantly more likely to be uprooted than seedlings and adult trees, while in the broad-leaved forest, the proportion of uprooted adult trees was significantly higher than that of seedlings and young trees. There were also differences among forest types in how tree age affected damage recovery. In the coniferous forest, the recovery rate of trees with broken trunks or crowns (DBH > 2.5 cm) increased with tree age. However, in the mixed and broad-leaved forests, no obvious correlation between the recovery rate of trees with broken trunks or crowns and tree age was observed. Trees with severe root damage did not recover; they were uprooted and died. In these forests, vegetation damage and recovery showed tree age dependencies, which varied

  20. The valuative tree

    CERN Document Server

    Favre, Charles

    2004-01-01

    This volume is devoted to a beautiful object, called the valuative tree and designed as a powerful tool for the study of singularities in two complex dimensions. Its intricate yet manageable structure can be analyzed by both algebraic and geometric means. Many types of singularities, including those of curves, ideals, and plurisubharmonic functions, can be encoded in terms of positive measures on the valuative tree. The construction of these measures uses a natural tree Laplace operator of independent interest.

  1. Trees in renorming theory

    OpenAIRE

    Haydon, Richard

    1995-01-01

    Trees are very agreeable objects to work with, offering a diversity of behaviour within a structure that is sufficiently simple to admit precise analysis. Thus we are able to offer fairly satisfactory necessary and sufficient conditions on a tree $\\Upsilon $ for the existence of equivalent LUR or strictly convex norms on $\\C_0(\\Upsilon )$ and for norms with the Kadec Property. In particular, we show that for a {\\sl finitely branching} tree $\\Upsilon $ the space $\\C_0(\\Upsilon )$ admits a Kade...

  2. Generalized Binomial Trees

    OpenAIRE

    Jackwerth, Jens Carsten

    1996-01-01

    We consider the problem of consistently pricing new options given the prices of related options on the same stock. The Black-Scholes formula and standard binomial trees can only accommodate one related European option which then effectively specifies the volatility parameter. Implied binomial trees can accommodate only related European options with the same time-to-expiration.The generalized binomial trees introduced here can accommodate any kind of related options (European, American, or exo...

  3. IMPACT OF Global Warming on Trees

    Energy Technology Data Exchange (ETDEWEB)

    Nasrullah Khan [COMSATS Institute of Information Technology, Islamabad (Pakistan); Naeem Abas [2Department of Electrical Engineering, University of Gujrat, Gujrat (Pakistan); Norman Mariun [University Putra Malaysia, Faculty of Engineering, UPM Serdang, Serdang (Malaysia)

    2008-09-30

    trees have been found to dry from top to bottom in all the known cases in Pakistan. As the water stops reaching top branches due to insect attack at tree-ground interface or reduced water table or both the tree leaves start drying from the top.

  4. D2-tree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Sioutas, Spyros; Pantazos, Kostas;

    2015-01-01

    We present a new overlay, called the Deterministic Decentralized tree (D2-tree). The D2-tree compares favorably to other overlays for the following reasons: (a) it provides matching and better complexities, which are deterministic for the supported operations; (b) the management of nodes (peers......-balancing scheme of elements into nodes is deterministic and general enough to be applied to other hierarchical tree-based overlays. This load-balancing mechanism is based on an innovative lazy weight-balancing mechanism, which is interesting in its own right....

  5. The tree BVOC index

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.R., E-mail: jrsimpson@ucdavis.edu [U.S. Forest Service, Pacific Southwest Research Station, Urban Ecosystems and Processes, 1731 Research Park Drive, Davis, CA 95616 (United States); McPherson, E.G. [U.S. Forest Service, Pacific Southwest Research Station, Urban Ecosystems and Processes, 1731 Research Park Drive, Davis, CA 95616 (United States)

    2011-08-15

    Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area. - Highlights: > A Tree BVOC index based on reduced emissions from low emitting trees is described. > An example illustrates use of the index as an implementation and monitoring tool. > This index could be useful for including urban trees in air quality mitigation plans. - A tree BVOC index is presented that calculates reduced BVOC emissions from planting lower-emitting urban tree species that has potential application for SIP compliance.

  6. Symmetric M-tree

    CERN Document Server

    Sexton, Alan P

    2010-01-01

    The M-tree is a paged, dynamically balanced metric access method that responds gracefully to the insertion of new objects. To date, no algorithm has been published for the corresponding Delete operation. We believe this to be non-trivial because of the design of the M-tree's Insert algorithm. We propose a modification to Insert that overcomes this problem and give the corresponding Delete algorithm. The performance of the tree is comparable to the M-tree and offers additional benefits in terms of supported operations, which we briefly discuss.

  7. A theory of game trees, based on solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie); A. Plaat (Aske)

    1996-01-01

    textabstractIn this paper a complete theory of game tree algorithms is presented, entirely based upon the notion of a solution tree. Two types of solution trees are distinguished: max and min solution trees respectively. We show that most game tree algorithms construct a superposition of a max and a

  8. Characterization of fatty alcohol and sterol fractions in olive tree.

    Science.gov (United States)

    Orozco-Solano, Mara; Ruiz-Jimenez, José; Luque De Castro, María D

    2010-07-14

    The determination of sterols and fatty alcohols is a part of the study of the metabolomic profile of the unsaponifiable fraction in olive tree. Leaves and drupes from three varieties of olive tree (Arbequina, Picual, and Manzanilla) were used. The content of the target compounds was studied in five ripeness stages and three harvesting periods for olive drupes and leaves, respectively. A method based on ultrasound-assisted extraction and derivatization for the individual identification and quantitation of sterols and fatty alcohols, involving chromatographic separation and mass spectrometry detection by selected ion monitoring, was used. The concentrations of alcohols and sterols in the drupes ranged between 0.1 and 1086.9 mug/g and between 0.1 and 5855.3 mug/g, respectively, which are higher than in leaves. Statistical studies were developed to show the relationship between the concentration of the target analytes and variety, ripeness stage, and harvesting period. PMID:20550122

  9. [Applicability analysis of spatially explicit model of leaf litter in evergreen broad-leaved forests].

    Science.gov (United States)

    Zhao, Qing-Qing; Liu, He-Ming; Jonard, Mathieu; Wang, Zhang-Hua; Wang, Xi-Hua

    2014-11-01

    The spatially explicit model of leaf litter can help to understand its dispersal process, which is very important to predict the distribution pattern of leaves on the surface of the earth. In this paper, the spatially explicit model of leaf litter was developed for 20 tree species using litter trap data from the mapped forest plot in an evergreen broad-leaved forest in Tiantong, Zhejiang Pro- vince, eastern China. Applicability of the model was analyzed. The model assumed an allometric equation between diameter at breast height (DBH) and leaf litter amount, and the leaf litter declined exponentially with the distance. Model parameters were estimated by the maximum likelihood method. Results showed that the predicted and measured leaf litter amounts were significantly correlated, but the prediction accuracies varied widely for the different tree species, averaging at 49.3% and ranging from 16.0% and 74.0%. Model qualities of tree species significantly correlated with the standard deviations of the leaf litter amount per trap, DBH of the tree species and the average leaf dry mass of tree species. There were several ways to improve the forecast precision of the model, such as installing the litterfall traps according to the distribution of the tree to cover the different classes of the DBH and distance apart from the parent trees, determining the optimal dispersal function of each tree species, and optimizing the existing dispersal function. PMID:25898606

  10. Influence of environmental pollution on leaf properties of urban plane trees, Platanus orientalis L.

    Science.gov (United States)

    Pourkhabbaz, Alireza; Rastin, Nayerah; Olbrich, Andrea; Langenfeld-Heyser, Rosemarie; Polle, Andrea

    2010-09-01

    To investigate whether leaves of plane trees (Platanus orientalis) are damaged by traffic pollution, trees from a megacity (Mashhad, Iran) and a rural area were investigated. Soil and air from the urban centre showed enrichment of several toxic elements, but only lead was enriched in leaves. Leaf size and stomata density were lower at the urban site. At the urban site leaf surfaces were heavily loaded by dust particles but the stomata were not occluded; the cuticle was thinner; other anatomical properties were unaffected suggesting that plane trees can cope with traffic exhaust in megacities.

  11. Influence of Environmental Pollution on Leaf Properties of Urban Plane Trees, Platanus orientalis L.

    Science.gov (United States)

    Pourkhabbaz, Alireza; Rastin, Nayerah; Olbrich, Andrea; Langenfeld-Heyser, Rosemarie

    2010-01-01

    To investigate whether leaves of plane trees (Platanus orientalis) are damaged by traffic pollution, trees from a megacity (Mashhad, Iran) and a rural area were investigated. Soil and air from the urban centre showed enrichment of several toxic elements, but only lead was enriched in leaves. Leaf size and stomata density were lower at the urban site. At the urban site leaf surfaces were heavily loaded by dust particles but the stomata were not occluded; the cuticle was thinner; other anatomical properties were unaffected suggesting that plane trees can cope with traffic exhaust in megacities. PMID:20577871

  12. Terpenoid variations within and among half-sibling avocado trees, Persea americana Mill. (Lauraceae).

    Science.gov (United States)

    Niogret, Jerome; Epsky, Nancy D; Schnell, Raymond J; Boza, Edward J; Kendra, Paul E; Heath, Robert R

    2013-01-01

    Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae). The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedlings initiated from a single maternal tree. Two-way analysis of variance was conducted on 34 chemicals that comprised at least 3% of the total chemical content of at least one tree and/or location within a tree. There were significant interactions between genotype and location sampled for most chemicals. Parentage analysis using microsatellite molecular markers (SSR's) determined that the four trees had three fathers and that they represented two full-siblings and two half-sibling trees. Descriptive discriminant analysis found that both genotype and location within a tree could be separated based on chemical content, and that the chemical content from full-siblings tended to be more similar than chemical content from half-siblings. To further explore the relationship between genetic background and chemical content, samples were analyzed from leaf material from 20 trees that included two sets of full-sibling seedling trees, the maternal tree and the surviving paternal tree. Descriptive discriminant analysis found good separation between the two full-sibling groups, and that the separation was associated with chemistry of the parental trees. Six groups of chemicals were identified that explained the variation among the trees. We discuss the results in relation to the discrimination process used by wood-boring insects for site-selection on host trees, for tree selection among potential host trees, and the potential use of terpenoid chemical content in chemotaxonomy of avocado trees.

  13. Terpenoid variations within and among half-sibling avocado trees, Persea americana Mill. (Lauraceae.

    Directory of Open Access Journals (Sweden)

    Jerome Niogret

    Full Text Available Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae. The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedlings initiated from a single maternal tree. Two-way analysis of variance was conducted on 34 chemicals that comprised at least 3% of the total chemical content of at least one tree and/or location within a tree. There were significant interactions between genotype and location sampled for most chemicals. Parentage analysis using microsatellite molecular markers (SSR's determined that the four trees had three fathers and that they represented two full-siblings and two half-sibling trees. Descriptive discriminant analysis found that both genotype and location within a tree could be separated based on chemical content, and that the chemical content from full-siblings tended to be more similar than chemical content from half-siblings. To further explore the relationship between genetic background and chemical content, samples were analyzed from leaf material from 20 trees that included two sets of full-sibling seedling trees, the maternal tree and the surviving paternal tree. Descriptive discriminant analysis found good separation between the two full-sibling groups, and that the separation was associated with chemistry of the parental trees. Six groups of chemicals were identified that explained the variation among the trees. We discuss the results in relation to the discrimination process used by wood-boring insects for site-selection on host trees, for tree selection among potential host trees, and the potential use of terpenoid chemical content in chemotaxonomy of avocado trees.

  14. Terpenoid variations within and among half-sibling avocado trees, Persea americana Mill. (Lauraceae).

    Science.gov (United States)

    Niogret, Jerome; Epsky, Nancy D; Schnell, Raymond J; Boza, Edward J; Kendra, Paul E; Heath, Robert R

    2013-01-01

    Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae). The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedlings initiated from a single maternal tree. Two-way analysis of variance was conducted on 34 chemicals that comprised at least 3% of the total chemical content of at least one tree and/or location within a tree. There were significant interactions between genotype and location sampled for most chemicals. Parentage analysis using microsatellite molecular markers (SSR's) determined that the four trees had three fathers and that they represented two full-siblings and two half-sibling trees. Descriptive discriminant analysis found that both genotype and location within a tree could be separated based on chemical content, and that the chemical content from full-siblings tended to be more similar than chemical content from half-siblings. To further explore the relationship between genetic background and chemical content, samples were analyzed from leaf material from 20 trees that included two sets of full-sibling seedling trees, the maternal tree and the surviving paternal tree. Descriptive discriminant analysis found good separation between the two full-sibling groups, and that the separation was associated with chemistry of the parental trees. Six groups of chemicals were identified that explained the variation among the trees. We discuss the results in relation to the discrimination process used by wood-boring insects for site-selection on host trees, for tree selection among potential host trees, and the potential use of terpenoid chemical content in chemotaxonomy of avocado trees. PMID:24039994

  15. Niches and interspecific associations of dominant tree populations at different restoration stages of monsoonal broad-leaved evergreen forest%季风常绿阔叶林不同恢复阶段乔木优势种群生态位和种间联结

    Institute of Scientific and Technical Information of China (English)

    李帅锋; 刘万德; 苏建荣; 张志钧

    2011-01-01

    Niche and interspecific association are one of the important contents in community dynamics research. Interspecific interaction affects the restoration and succession of community. In this paper, field investigation was made on the community structure of monsoonal broad-leaved evergreen forest at its different restoration stages ( primary forest, PF; 15 years restoration, 15R; and 30 years restoration, 30R) in Pu ’ er City of Yunnan Province, and the niche breadth, niche overlap, and variance ratio ( VR) as well as the chi-square test and association coefficient (AC) based on 2×2 contingency table were used to analyze the change trend of the dominant tree populations at different restoration stages. In the three communities at different restoration stages, there was a significant positive correlation (P<0. 001 ) between the importance value and corresponding niche breadth. 78. 22% of species pairs at 15R had a niche overlap 0. 4-0. 8, suggesting a strong resource utilization competition in dominant species; while the community structure at PF and 30R was rather stable , and the species with higher niche breadth had a higher niche overlap than those with lower niche breadth , reflecting that the dominant species had stronger competitiveness. At 15R and 30R. there was a positive interspecific association; while at PF, there was a negative association. In the three communities, most species pairs had no significant association, showed stronger independency, and the proportions of positive and negative associations decreased with the process of restoration. There was a significant positive correlation between the association coefficient and niches overlap at different restoration stages, i. e. , the high the niche overlap, the greater the association coefficient.%生态位和种间联结是群落动态研究的重要内容之一,物种间相互作用影响着群落的恢复和演替.本文在对云南普洱地区不同恢复阶段(恢复15年、恢复30年和

  16. Flavonoids from the leaves of Iranian Linden; Tilia rubra subsp. caucasica

    OpenAIRE

    M.R. Delnavazi; Shahabi, M.; N. Yassa

    2015-01-01

    Background and objectives: Plants belonging to the genus Tilia L. (Tiliaceae) are often tall beautiful trees which are considered for various medicinal potentials of their flowers and leaves. The present study was an attempt to investigate the phytochemical constituents of Tilia rubra subsp. caucasica leaves from the hyrcanian forests of north of Iran. Methods: Chromatography on Silica gel (normal and reversed-phase) and Sephadex LH20 was applied for isolation and purification of the compound...

  17. Change in Species Diversity during Recovering Process of Evergreen Broad-leaved Fo rest

    Institute of Scientific and Technical Information of China (English)

    WenYuanguang; LiuShirong; ChenFang; HeTatping; LiangHongwen

    2005-01-01

    Evergreen broad-leaved forest is one of the most important vegetation types in China. Because of the human activities, evergreen broad-leaved forest has been destroyed extensively, leading to degraded ecosystem. It is urgent to conserve and restore these natural forests in China.tn this paper, the tendency and rate of species diversity restoration of the evergreen broad-lea ved forest in Darning Mountain has been studied. The main results are as follows:(a) in subtropical mid-mountain area, species diversity in degraded evergreen broad-leaved forest can be restored. Through analyzing b diversity index of communities in different time and space, it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest. (b) The restoration rate of evergreen broad-leaved forest was very fast. Planting Chinese fir after clear-cutting and controlled burning of the forest 178 species appeared in a 60Om2, sample area after 20 years"" natural recovering. Among these species, 58 were tree layer and the height of community reached 18m, The survey suggested that it would take only 20 years for the degraded forest to develop into community composed of light demanding broad-leaved pioneer trees and rain-tolerance broad-leaved trees, and it need another 40-80 years to reach the stage consisting of min-tulerance evergreen broad-leaved trees, (c) Species number increased quickly at the early stage (2-20 years) during vegetation recovering process toward the climax, and decreased at the min-stage (50-60 years ), then maintained a relatively stable level at the late-stage (over 150 years).

  18. Direct and indirect contamination of tree crops with Cs-134

    International Nuclear Information System (INIS)

    A long term glasshouse pot experiment was established in 1994 to study the transfer factors of Cs-134 from soil to olive and orange trees for which no relevant data are available. A calcareous-heavy textured and an acid-light textured soil were used in this experiment. Results from two year's experimentation are considered in this study. The ability of the studied plant species for Cs-134 root uptake seems to be significantly influenced by soil type. The contamination of both tree species grown on calcareous and heavy soil was very low and did not change much with the time. On the contrary, trees grown on acid and light soil showed much higher Cs-134 concentration (up to 34 times for orange and 23 for olive trees) which significantly increased with the time. Both olive and orange trees showed a similar behaviour in the studied soils. Effort was also made to study the long term consequences of the direct contamination in a field experiment where an olive tree was contaminated by dry deposition with Cs-134. Six months after contamination 5 % of the Cs-134 deposited on the leaves was measured in the first olive production. However, very small quantities (= 0.5 %) of the olive Cs-134 was detected in the unprocessed olive oil. The following year 15 % of the Cs-134 remained in the leaves while extremely low quantities of Cs-134 were detected in either olives or olive oil. (author)

  19. Starch metabolism in leaves.

    Science.gov (United States)

    Orzechowski, Sławomir

    2008-01-01

    Starch is the most abundant storage carbohydrate produced in plants. The initiation of transitory starch synthesis and degradation in plastids depends mainly on diurnal cycle, post-translational regulation of enzyme activity and starch phosphorylation. For the proper structure of starch granule the activities of all starch synthase isoenzymes, branching enzymes and debranching enzymes are needed. The intensity of starch biosynthesis depends mainly on the activity of AGPase (adenosine 5'-diphosphate glucose pyrophosphorylase). The key enzymes in starch degradation are beta-amylase, isoamylase 3 and disproportionating enzyme. However, it should be underlined that there are some crucial differences in starch metabolism between heterotrophic and autotrophic tissues, e.g. is the ability to build multiprotein complexes responsible for biosynthesis and degradation of starch granules in chloroplasts. The observed huge progress in understanding of starch metabolism was possible mainly due to analyses of the complete Arabidopsis and rice genomes and of numerous mutants with altered starch metabolism in leaves. The aim of this paper is to review current knowledge on transient starch metabolism in higher plants. PMID:18787712

  20. REMINDER Saved Leave Scheme (SLS) : Simplified procedure for the transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2001-01-01

    As part of the process of streamlining procedures, the HR and AS Divisions have jointly developed a system whereby annual and compensatory leave will henceforth be automatically transferred1) to saved leave accounts. Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'2)Previously, every person taking part in the scheme has been individually issued with a form for the purposes of requesting the transfer of leave to the leave account and the transfer has then had to be done manually by HR Division. To streamline the procedure, unused leave of all those taking part in the saved leave scheme at the closure of the leave-year accounts will henceforth be transferred automatically to the saved leave account on that date. This simplification is in the interest of all parties concerned. This automatic transfer procedure has a number of advantages for participants in the SLS scheme. First, staff members will no longer have to take any administrative steps. Secondly, the new proced...

  1. Searching informed game trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie)

    1992-01-01

    textabstractWell-known algorithms for the evaluation of the minimax function in game trees are alpha-beta and SSS*. An improved version of SSS* is SSS-2. All these algorithms don't use any heuristic information on the game tree. In this paper the use of heuristic information is introduced into the a

  2. Structural Equation Model Trees

    Science.gov (United States)

    Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman

    2013-01-01

    In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree…

  3. Matching Subsequences in Trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2009-01-01

    Given two rooted, labeled trees P and T the tree path subsequence problem is to determine which paths in P are subsequences of which paths in T. Here a path begins at the root and ends at a leaf. In this paper we propose this problem as a useful query primitive for XML data, and provide new...

  4. Pruning peach trees

    OpenAIRE

    Sagers, Larry A.

    1988-01-01

    Discusses the importance of annual pruning to produce high yield and quality of peaches. Advises that the successful pruner should understand how the trees grow, and how the trees respond to pruning. Also cautions that improper pruning will lower yield and quality of fruit.

  5. Tree nut oils

    Science.gov (United States)

    The major tree nuts include almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachio nuts, and walnuts. Tree nut oils are appreciated in food applications because of their flavors and are generally more expensive than other gourmet oils. Research during the last de...

  6. Inferring epidemic contact structure from phylogenetic trees.

    Directory of Open Access Journals (Sweden)

    Gabriel E Leventhal

    Full Text Available Contact structure is believed to have a large impact on epidemic spreading and consequently using networks to model such contact structure continues to gain interest in epidemiology. However, detailed knowledge of the exact contact structure underlying real epidemics is limited. Here we address the question whether the structure of the contact network leaves a detectable genetic fingerprint in the pathogen population. To this end we compare phylogenies generated by disease outbreaks in simulated populations with different types of contact networks. We find that the shape of these phylogenies strongly depends on contact structure. In particular, measures of tree imbalance allow us to quantify to what extent the contact structure underlying an epidemic deviates from a null model contact network and illustrate this in the case of random mixing. Using a phylogeny from the Swiss HIV epidemic, we show that this epidemic has a significantly more unbalanced tree than would be expected from random mixing.

  7. PaisleyTrees: A Size-Invariant Tree Visualization

    Directory of Open Access Journals (Sweden)

    Katayoon Etemad

    2014-10-01

    Full Text Available Squeezing large tree structures into suitable visualizations has been a perennial problem. In response to this challenge, we present PaisleyTrees, a size-invariant tree visualization. PaisleyTrees integrate node-of-interest focus with tree-cut presentations to support rapid tree navigation without resorting to zooming and panning. This visualization offers the ability to work with trees of arbitrary depth and breadth, and maintains legibility for displayed elements. These advantages are achieved by using a hybrid layout, inspired by traditional Paisley patterns, that combines node-link, nested and djacency-based tree layout techniques, and offers both depth and breadth elision.

  8. Accessibility percolation on n-trees

    OpenAIRE

    Nowak, Stefan; Krug, Joachim

    2013-01-01

    Accessibility percolation is a new type of percolation problem inspired by evolutionary biology. To each vertex of a graph a random number is assigned and a path through the graph is called accessible if all numbers along the path are in ascending order. For the case when the random variables are independent and identically distributed, we derive an asymptotically exact expression for the probability that there is at least one accessible path from the root to the leaves in an $n$-tree. This p...

  9. 透光抚育对长白山"栽针保阔"红松林土壤碳储量影响%Effect of liberation cutting on the soil carbon storage of a Korean pine forest restored by planting conifers and reserving broad-leaved trees in Changbai Mountains of China.

    Institute of Scientific and Technical Information of China (English)

    张晓亮; 牟长城; 张小单; 韩阳瑞; 庄宸; 曹万亮; 程家友; 郑曈

    2015-01-01

    We studied the effect of liberation cutting on the soil carbon storage and the litter carbon storage of a mid-term (33-year-old) Korean pine forest which was restored by planting conifers and reserving broad-leaved trees by using crown thinning control test method in Changbai Mountains of China. Five levels of cutting intensity were applied, namely, non-cutting ( control) , mild liberation cutting (25%) , moderate liberation cutting ( 50%) , heavy liberation cutting ( 75%) , and clear cutting ( 100%) ( cutting intensity refers to volume percentage) . The main research results were as follows. The liberation cutting had certain effects on the soil bulk density ((0. 83 ± 0. 02) -(1. 15 ± 0. 03)g/cm3) and the soil carbon concentration ((43. 36 ± 1. 60) -(70. 26 ± 1. 94) g/kg) of the Korean pine forest. Compared to the control, moderate liberation cutting decreased the soil bulk density by 8. 4% (P<0. 05), but increased the soil carbon concentration by 14. 9% ( P<0. 05 ) . Heavy liberation cutting and clear cutting increased the soil bulk density by 23. 3% and 27. 1% ( P<0. 05 ) , and degraded the soil carbon concentration by 23. 7% and 29. 1%, respectively ( P<0. 05 ) . Mild liberation cutting had no significant effect on the two parameters. The liberation cutting had great effect on the soil carbon storage ((13. 12 ± 1. 57)-(23. 46 ± 2. 03) kg/m2) of the Korean pine forest. Compared to the control, moderate liberation cutting led to the increase of soil carbon storage by 12. 8% ( P<0. 05 ) , while heavy liberation cutting and clear cutting lowered it by 29. 9% and 36. 9%, respectively ( P<0. 05 ) . Mild liberation cutting had no significant effect on it. The liberation cutting had remarkable effect on the litter carbon storage( (2. 13 ± 0. 39) -(2. 82 ± 0. 37) t/ha) of the Korean pine forest. Moderate liberation cutting resulted in the increase of the litter carbon storage by 19. 5% ( P<0. 05 ) compared to the control, while clear cutting reduced it by 9. 8

  10. A sub-cubic time algorithm for computing the quartet distance between two general trees

    Directory of Open Access Journals (Sweden)

    Mailund Thomas

    2011-06-01

    Full Text Available Abstract Background When inferring phylogenetic trees different algorithms may give different trees. To study such effects a measure for the distance between two trees is useful. Quartet distance is one such measure, and is the number of quartet topologies that differ between two trees. Results We have derived a new algorithm for computing the quartet distance between a pair of general trees, i.e. trees where inner nodes can have any degree ≥ 3. The time and space complexity of our algorithm is sub-cubic in the number of leaves and does not depend on the degree of the inner nodes. This makes it the fastest algorithm so far for computing the quartet distance between general trees independent of the degree of the inner nodes. Conclusions We have implemented our algorithm and two of the best competitors. Our new algorithm is significantly faster than the competition and seems to run in close to quadratic time in practice.

  11. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  12. Phylogenetic trees in bioinformatics

    Energy Technology Data Exchange (ETDEWEB)

    Burr, Tom L [Los Alamos National Laboratory

    2008-01-01

    Genetic data is often used to infer evolutionary relationships among a collection of viruses, bacteria, animal or plant species, or other operational taxonomic units (OTU). A phylogenetic tree depicts such relationships and provides a visual representation of the estimated branching order of the OTUs. Tree estimation is unique for several reasons, including: the types of data used to represent each OTU; the use ofprobabilistic nucleotide substitution models; the inference goals involving both tree topology and branch length, and the huge number of possible trees for a given sample of a very modest number of OTUs, which implies that fmding the best tree(s) to describe the genetic data for each OTU is computationally demanding. Bioinformatics is too large a field to review here. We focus on that aspect of bioinformatics that includes study of similarities in genetic data from multiple OTUs. Although research questions are diverse, a common underlying challenge is to estimate the evolutionary history of the OTUs. Therefore, this paper reviews the role of phylogenetic tree estimation in bioinformatics, available methods and software, and identifies areas for additional research and development.

  13. The distribution of weaver ant pheromones on host trees

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2007-01-01

    The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested...... for correlations between spot density, ant activity and the likelihood of being detected by an ant. Spots were only found on trees with ants. On ant-trees, spots were distributed throughout the trees but with higher densities in areas with high ant activity and pheromone densities were higher on twigs compared...... to leaves. Also there was a positive correlation between spot density and the likelihood of being detected by ants. Anal spots may thus function as reliable cues to interacting species and be an important factor in shaping the community around Oecophylla colonies....

  14. The saproxylic beetle assemblage associated with different host trees in Southwest China

    Institute of Scientific and Technical Information of China (English)

    Jie Wu; Xiao-Dong Yu; Hong-Zhang Zhou

    2008-01-01

    Dead wood is a habitat for many insects and other small animals,some of which may be rare or endangered and in need of effective protection.In this paper,saproxylic beetle assemblages associated with different host trees in the subtropical forests in southwestern China were investigated.A total of 277 species (1 439 specimens) in 36 beetle families were collected from 117 dead wood samples,of which 101 samples were identified and respectively belonged to 12 tree genera.The number of saproxylic beetle species varied greatly among logs of different tree genera,with the highest diversity on logs of Juglans.Generally,broad-leaved trees had a higher richness and abundance of saproxylic species than coniferous trees.Cluster analysis revealed that assemblages from broad-leaved tree genera were generally similar (except for Betula) and assemblages from coniferous trees formed another distinct cluster.The subsequent indicator analysis proposed that there are different characteristic species for different cluster groups of host tree genera.In our study,log diameter has no positive influence on beetle species density.Conversely,comparisons of individual-based rarefaction curves suggested that beetle species richness was highest in the small diameter class both in coniferous and broad-leaved tree genera.With increased wood decay,proportion of habitat specialists (saproxylic beetles living on one tree genus)decreased,whereas proportion of habitat generalists (living on more than three tree genera)increased.The beetle species density was found to be higher in early stages,and decreased in later stages as well.A negative influence of altitude on saproxylic beetle species richness and abundance was detected.It was indicated that different tree genera and altitudes possibly display cross effects in modulating the altitudinal distribution and host preference of the beetles.

  15. Compatible spanning trees

    OpenAIRE

    Garcia Olaverri, Alfredo Martin; Huemer, Clemens; Hurtado Díaz, Fernando Alfredo; Tejel Altarriba, Francisco Javier

    2014-01-01

    Two plane geometric graphs are said to be compatible when their union is a plane geometric graph. Let S be a set of n points in the Euclidean plane in general position and let T be any given plane geometric spanning tree of S. In this work, we study the problem of finding a second plane geometric tree T' spanning S, such that is compatible with T and shares the minimum number of edges with T. We prove that there is always a compatible plane geometric tree T' having at most #n - 3#/4 edges in ...

  16. LIMSUP DEVIATIONS ON TREES

    Institute of Scientific and Technical Information of China (English)

    Fan Aihua

    2004-01-01

    The vertices of an infinite locally finite tree T are labelled by a collection of i.i.d. real random variables {Xσ}σ∈T which defines a tree indexed walk Sσ = ∑θ<r≤σXr. We introduce and study the oscillations of the walk:Exact Hausdorff dimension of the set of such ξ 's is calculated. An application is given to study the local variation of Brownian motion. A general limsup deviation problem on trees is also studied.

  17. The gravity apple tree

    Science.gov (United States)

    Espinosa Aldama, Mariana

    2015-04-01

    The gravity apple tree is a genealogical tree of the gravitation theories developed during the past century. The graphic representation is full of information such as guides in heuristic principles, names of main proponents, dates and references for original articles (See under Supplementary Data for the graphic representation). This visual presentation and its particular classification allows a quick synthetic view for a plurality of theories, many of them well validated in the Solar System domain. Its diachronic structure organizes information in a shape of a tree following similarities through a formal concept analysis. It can be used for educational purposes or as a tool for philosophical discussion.

  18. Key Obama officials leave administration

    Science.gov (United States)

    Showstack, Randy

    2013-01-01

    Secretary of the Interior Ken Salazar is one of the latest members of the Obama administration to announce that he is leaving his position near the start of President Obama's second term in office. Salazar, who has served as interior secretary since January 2009, intends to leave the department by the end of March, the department noted on 16 January. Salazar joins a number of other key officials who are planning to leave the administration. They include Environmental Protection Agency administrator Lisa Jackson, National Oceanic and Atmospheric Administration administrator Jane Lubchenco, and U.S. Geological Survey director Marcia McNutt.

  19. New statement of leave format

    CERN Multimedia

    HR Department

    2009-01-01

    Following the communication of the Standing Concertation Committee published in Weekly Bulletin No. 18-19 of 27 April 2009, the current statement of leave on monthly pay slips has been replaced with the EDH Leave Transactions report that displays the up-to-date situation of individual leave balances at all times. The report is available on EDH. Additionally, the layout of the pay slip has been modernised. The new version of the pay slip will be send out from September 2009 onwards. Finance and Purchasing Department, Personnel Accounting Human Resources Department, Organisation and Procedures General Infrastructure Services Department, Administrative Information Services

  20. Interactive tree of life (iTOL) v3: an online tool for the display and annotation of phylogenetic and other trees.

    Science.gov (United States)

    Letunic, Ivica; Bork, Peer

    2016-07-01

    Interactive Tree Of Life (http://itol.embl.de) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. It is freely available and open to everyone. The current version was completely redesigned and rewritten, utilizing current web technologies for speedy and streamlined processing. Numerous new features were introduced and several new data types are now supported. Trees with up to 100,000 leaves can now be efficiently displayed. Full interactive control over precise positioning of various annotation features and an unlimited number of datasets allow the easy creation of complex tree visualizations. iTOL 3 is the first tool which supports direct visualization of the recently proposed phylogenetic placements format. Finally, iTOL's account system has been redesigned to simplify the management of trees in user-defined workspaces and projects, as it is heavily used and currently handles already more than 500,000 trees from more than 10,000 individual users.

  1. Left and right length of paths in binary trees or on a question of Knuth

    OpenAIRE

    Panholzer, Alois

    2006-01-01

    International audience; We consider extended binary trees and study the common right and left depth of leaf j, where the leaves are labelled from left to right by 0, 1, \\ldots, n, and the common right and left external pathlength of binary trees of size n. Under the random tree model, i.e., the Catalan model, we characterize the common limiting distribution of the suitably scaled left depth and the difference between the right and the left depth of leaf j in a random size-n binary tree when j...

  2. Extractability of radiocesium from processed green tea leaves with hot water. The first emergent tea leaves harvested after the TEPCO's Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    In some tea tree planting areas within 300 km from the TEPCO's Fukushima Daiichi Nuclear Power Plant (FNPP), it was found that newly emerged tea plant leaves for green tea contained two radiocesium species (cesium-134 and cesium-137). In this study, using processed green tea leaves for drinking, extraction ratios of radiocesium under several brew conditions were observed. When 90 deg C water was used, 50-70% of radiocesium was extracted into the water, while 54-60% of radiocesium was extracted with 60 deg C water. A part of radiocesium would be removed from leaves if the leaves were washed with 20 and 60 deg C water before brewing, and the efficiencies were 11 and 32%, respectively. Newly emerged camellia leaves were used to simulate the radiocesium removal ratio from raw tea leaves by washing and boiling; radioactivity concentration was decreased to 60% of the original concentration with washing and 10 min boiling. From these results, it was found that almost half of the radiocesium would not be removed from raw or processed tea leaves. The values obtained in the present study could be used for internal radiation dose estimation from tea leaves. (author)

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

    NARCIS (Netherlands)

    Eilmann, B.; Rigling, A.

    2012-01-01

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

  4. A Characterization of the average tree solution for tree games

    OpenAIRE

    Debasis Mishra; Dolf Talman

    2009-01-01

    For the class of tree games, a new solution called the average tree solution has been proposed recently. We provide a characterization of this solution. This characterization underlines an important difference, in terms of symmetric treatment of the agents, between the average tree solution and the Myerson value for the class of tree games.

  5. ControlTree: Navigating and Selecting in a Large Tree

    OpenAIRE

    Appert, Caroline; Fekete, Jean-Daniel

    2006-01-01

    International audience We introduce ControlTree, a novel interface using crossing interaction to navigate and select nodes in a large tree. ControlTree combines an optimized dynamic layout with interaction features to quickly reach a node in a node-link tree representation.

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

    Directory of Open Access Journals (Sweden)

    Dar A. Roberts

    2012-06-01

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

  7. Tree-like tableaux

    CERN Document Server

    Aval, Jean-Christophe; Nadeau, Philippe

    2011-01-01

    In this work we introduce and study tree-like tableaux, which are certain fillings of Ferrers diagrams in simple bijection with permutation tableaux and alternative tableaux. We exhibit an elementary insertion procedure on our tableaux which gives a clear proof that tableaux of size n are counted by n!, and which moreover respects most of the well-known statistics studied originally on alternative and permutation tableaux. Our insertion procedure allows to define in particular two simple new bijections between tree-like tableaux and permutations: the first one is conceived specifically to respect the generalized pattern 2-31, while the second one respects the underlying tree of a tree-like tableau.

  8. The tree BVOC index.

    Science.gov (United States)

    Simpson, J R; McPherson, E G

    2011-01-01

    Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area. PMID:21435760

  9. Loops and trees

    Science.gov (United States)

    Caron-Huot, S.

    2011-05-01

    We investigate relations between loop and tree amplitudes in quantum field theory that involve putting on-shell some loop propagators. This generalizes the so-called Feynman tree theorem which is satisfied at 1-loop. Exploiting retarded boundary conditions, we give a generalization to ℓ-loop expressing the loops as integrals over the on-shell phase space of exactly ℓ particles. We argue that the corresponding integrand for ℓ > 2 does not involve the forward limit of any physical tree amplitude, except in planar gauge theories. In that case we explicitly construct the relevant physical amplitude. Beyond the planar limit, abandoning direct integral representations, we propose that loops continue to be determined implicitly by the forward limit of physical connected trees, and we formulate a precise conjecture along this line. Finally, we set up technology to compute forward amplitudes in supersymmetric theories, in which specific simplifications occur.

  10. A parallel buffer tree

    DEFF Research Database (Denmark)

    Sitchinava, Nodar; Zeh, Norbert

    2012-01-01

    We present the parallel buffer tree, a parallel external memory (PEM) data structure for batched search problems. This data structure is a non-trivial extension of Arge's sequential buffer tree to a private-cache multiprocessor environment and reduces the number of I/O operations by the number...... of available processor cores compared to its sequential counterpart, thereby taking full advantage of multicore parallelism. The parallel buffer tree is a search tree data structure that supports the batched parallel processing of a sequence of N insertions, deletions, membership queries, and range queries...... in the optimal OhOf(psortN + K/PB) parallel I/O complexity, where K is the size of the output reported in the process and psortN is the parallel I/O complexity of sorting N elements using P processors....

  11. NLCD 2001 - Tree Canopy

    Data.gov (United States)

    Minnesota Department of Natural Resources — The National Land Cover Database 2001 tree canopy layer for Minnesota (mapping zones 39-42, 50-51) was produced through a cooperative project conducted by the...

  12. Robustness of a routing tree for the Push Tree Problem

    OpenAIRE

    Havet, Frédéric

    2002-01-01

    The Push Tree problem contains elements from both the Steiner Tree and Shortest Path problem. It deals with the trade-offs between the push and pull mechanism used in information distribution and retrieval. In , a two step approach for the Push Tree Problem was proposed. In the first step, a «good» spanning tree (called routing tree) is constructed and then the problem is solved in this particular tree. Finding a routing tree is NP-hard but the second step may be performed easily, thus the id...

  13. Type extension trees

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2006-01-01

    We introduce type extension trees as a formal representation language for complex combinatorial features of relational data. Based on a very simple syntax this language provides a unified framework for expressing features as diverse as embedded subgraphs on the one hand, and marginal counts...... of attribute values on the other. We show by various examples how many existing relational data mining techniques can be expressed as the problem of constructing a type extension tree and a discriminant function....

  14. Information flow on trees

    OpenAIRE

    Mossel, Elchanan; Peres, Yuval

    2003-01-01

    Consider a tree network $T$, where each edge acts as an independent copy of a given channel $M$, and information is propagated from the root. For which $T$ and $M$ does the configuration obtained at level $n$ of $T$ typically contain significant information on the root variable? This problem arose independently in biology, information theory and statistical physics. ¶ For all $b$, we construct a channel for which the variable at the root of the break $b$-ary tree is...

  15. Urban tree mortality

    OpenAIRE

    Roman, Lara Angelica

    2013-01-01

    Urban forests have aesthetic, environmental, human health, and economic benefits that motivate tree planting programs. Realizing these benefits depends on tree survival. Cost-benefit analyses for urban forest ecosystem services are sensitive to mortality rate assumptions and associated population projections. However, long-term mortality data is needed to assess the accuracy of these assumptions. Analytical tools from demography, such as life tables, mortality curves, and survival analysis, c...

  16. Tree Improvement Glossary

    DEFF Research Database (Denmark)

    Schmidt, Lars Holger

    Forest tree improvement encompasses a number of scientific and technical areas like floral-, reproductive- and micro-biology, genetics breeding methods and strategies, propagation, gene conservation, data analysis and statistics, each area with a comprehensive terminology. The terms selected...... for definition here are those most frequently used in tree improvement literature. Clonal propagation is included in the view of the great expansion of that field as a means of mass multiplication of improved material....

  17. Tree felling 2014

    CERN Multimedia

    2014-01-01

    With a view to creating new landscapes and making its population of trees safer and healthier, this winter CERN will complete the tree-felling campaign started in 2010.   Tree felling will take place between 15 and 22 November on the Swiss part of the Meyrin site. This work is being carried out above all for safety reasons. The trees to be cut down are at risk of falling as they are too old and too tall to withstand the wind. In addition, the roots of poplar trees are very powerful and spread widely, potentially damaging underground networks, pavements and roadways. Compensatory tree planting campaigns will take place in the future, subject to the availability of funding, with the aim of creating coherent landscapes while also respecting the functional constraints of the site. These matters are being considered in close collaboration with the Geneva nature and countryside directorate (Direction générale de la nature et du paysage, DGNP). GS-SE Group

  18. Geometric Decision Tree

    CERN Document Server

    Manwani, Naresh

    2010-01-01

    In this paper we present a new algorithm for learning oblique decision trees. Most of the current decision tree algorithms rely on impurity measures to assess the goodness of hyperplanes at each node while learning a decision tree in a top-down fashion. These impurity measures do not properly capture the geometric structures in the data. Motivated by this, our algorithm uses a strategy to assess the hyperplanes in such a way that the geometric structure in the data is taken into account. At each node of the decision tree, we find the clustering hyperplanes for both the classes and use their angle bisectors as the split rule at that node. We show through empirical studies that this idea leads to small decision trees and better performance. We also present some analysis to show that the angle bisectors of clustering hyperplanes that we use as the split rules at each node, are solutions of an interesting optimization problem and hence argue that this is a principled method of learning a decision tree.

  19. 46 CFR 310.8 - Leave.

    Science.gov (United States)

    2010-10-01

    ... (7) days. (3) Annual leave shall not exceed thirty (30) days. (4) Christmas and Easter leave shall..., as authorized by the school, not to exceed four (4) months. (2) Christmas and Easter leave and...

  20. Molecular and physiological responses of trees to waterlogging stress.

    Science.gov (United States)

    Kreuzwieser, Jürgen; Rennenberg, Heinz

    2014-10-01

    One major effect of global climate change will be altered precipitation patterns in many regions of the world. This will cause a higher probability of long-term waterlogging in winter/spring and flash floods in summer because of extreme rainfall events. Particularly, trees not adapted at their natural site to such waterlogging stress can be impaired. Despite the enormous economic, ecological and social importance of forest ecosystems, the effect of waterlogging on trees is far less understood than the effect on many crops or the model plant Arabidopsis. There is only a handful of studies available investigating the transcriptome and metabolome of waterlogged trees. Main physiological responses of trees to waterlogging include the stimulation of fermentative pathways and an accelerated glycolytic flux. Many energy-consuming, anabolic processes are slowed down to overcome the energy crisis mediated by waterlogging. A crucial feature of waterlogging tolerance is the steady supply of glycolysis with carbohydrates, particularly in the roots; stress-sensitive trees fail to maintain sufficient carbohydrate availability resulting in the dieback of the stressed tissues. The present review summarizes physiological and molecular features of waterlogging tolerance of trees; the focus is on carbon metabolism in both, leaves and roots of trees.

  1. Can a fast­growing early­successional tree (Ochroma pyramidale, Malvaceae) accelerate forest succession?

    NARCIS (Netherlands)

    Vleut, I.; Levy-Tacher, S.I.; Boer, de W.F.; Galindo-Gonzalez, J.; Ramirez-Marcial, N.

    2013-01-01

    Species-specific traits of trees affect ecosystem dynamics, defining forest structure and understorey development. Ochroma pyramidale is a fast-growing tree species, with life-history traits that include low wood density, short-lived large leaves and a narrow open thin crown. We evaluated forest suc

  2. Behavior Trees for Evolutionary Robotics.

    Science.gov (United States)

    Scheper, Kirk Y W; Tijmons, Sjoerd; de Visser, Cornelis C; de Croon, Guido C H E

    2016-01-01

    Evolutionary Robotics allows robots with limited sensors and processing to tackle complex tasks by means of sensory-motor coordination. In this article we show the first application of the Behavior Tree framework on a real robotic platform using the evolutionary robotics methodology. This framework is used to improve the intelligibility of the emergent robotic behavior over that of the traditional neural network formulation. As a result, the behavior is easier to comprehend and manually adapt when crossing the reality gap from simulation to reality. This functionality is shown by performing real-world flight tests with the 20-g DelFly Explorer flapping wing micro air vehicle equipped with a 4-g onboard stereo vision system. The experiments show that the DelFly can fully autonomously search for and fly through a window with only its onboard sensors and processing. The success rate of the optimized behavior in simulation is 88%, and the corresponding real-world performance is 54% after user adaptation. Although this leaves room for improvement, it is higher than the 46% success rate from a tuned user-defined controller. PMID:26606468

  3. Behavior Trees for Evolutionary Robotics.

    Science.gov (United States)

    Scheper, Kirk Y W; Tijmons, Sjoerd; de Visser, Cornelis C; de Croon, Guido C H E

    2016-01-01

    Evolutionary Robotics allows robots with limited sensors and processing to tackle complex tasks by means of sensory-motor coordination. In this article we show the first application of the Behavior Tree framework on a real robotic platform using the evolutionary robotics methodology. This framework is used to improve the intelligibility of the emergent robotic behavior over that of the traditional neural network formulation. As a result, the behavior is easier to comprehend and manually adapt when crossing the reality gap from simulation to reality. This functionality is shown by performing real-world flight tests with the 20-g DelFly Explorer flapping wing micro air vehicle equipped with a 4-g onboard stereo vision system. The experiments show that the DelFly can fully autonomously search for and fly through a window with only its onboard sensors and processing. The success rate of the optimized behavior in simulation is 88%, and the corresponding real-world performance is 54% after user adaptation. Although this leaves room for improvement, it is higher than the 46% success rate from a tuned user-defined controller.

  4. Stable-carbon isotope variability in tree foliage and wood

    International Nuclear Information System (INIS)

    This study documents variation of stable-carbon isotope ratios (13C/12C) in trees of genera Juniperus and Pinus under field conditions. Results are from cellulose analysis on leaves, twigs, and wood from a number of localities in the southwestern US. Substantial variability, typically 1-3%, exists among leaves, within wood (radially, vertically, circumferentially), and between individuals at a site. These results may help guide sampling in tracer-type studies with stable-carbon isotope ratios and aid in the interpretation of isotopic results from such studies

  5. Reconciling species-level vs plastic responses of evergreen leaf structure to light gradients: shade leaves punch above their weight.

    Science.gov (United States)

    Lusk, Christopher H; Onoda, Yusuke; Kooyman, Robert; Gutiérrez-Girón, Alba

    2010-04-01

    *When grown in a common light environment, the leaves of shade-tolerant evergreen trees have a larger leaf mass per unit area (LMA) than their light-demanding counterparts, associated with differences in lifespan. Yet plastic responses of LMA run counter to this pattern: shade leaves have smaller LMA than sun leaves, despite often living longer. *We measured LMA and cell wall content, and conducted punch and shear tests, on sun and shade leaves of 13 rainforest evergreens of differing shade tolerance, in order to understand adaptation vs plastic responses of leaf structure and biomechanics to shade. *Species shade tolerance and leaf mechanical properties correlated better with cell wall mass per unit area than with LMA. Growth light environment had less effect on leaf mechanics than on LMA: shade leaves had, on average, 40% lower LMA than sun leaves, but differences in work-to-shear, and especially force-to-punch, were smaller. This was associated with a slightly larger cell wall fraction in shade leaves. *The persistence of shade leaves might reflect unattractiveness to herbivores because they yield smaller benefits (cell contents per area) per unit fracture force than sun leaves. In forest trees, cell wall fraction and force-to-punch are more robust correlates of species light requirements than LMA.

  6. Determination of high molecular mass compounds from Amazonian plant's leaves

    International Nuclear Information System (INIS)

    The fractions of dichloromethane extracts of leaves from andiroba (Carapa guianensis - Meliaceae), caapi (Banisteriopsis caapi - Malpighiaceae), cocoa (Theobroma cacao - Sterculiaceae), Brazil nut (Bertholletia excelsa - Lecytidaceae), cupuacu (Theobroma grandiflorum - Sterculiaceae), marupa (Simaruba amara - Simaroubaceae) and rubber tree (Hevea brasiliensis - Euphorbiaceae), were analyzed by HT-HRGC and HT-HRGC-MS. Esters of homologous series of fatty acids and long chain alcohols, phytol, amyrines and tocopherols were characterized. The characterization of the compounds was based mainly in mass spectra data and in addition by usual spectrometric data (1H and 13C NMR, IR). (author)

  7. PHYTOCHEMICAL SCREENING OF NERIUM OLEANDER LEAVES AND MOMORDICA CHARANTIA LEAVES

    Directory of Open Access Journals (Sweden)

    Santhi R

    2011-01-01

    Full Text Available The developing countries mostly rely on traditional medicines. The traditional medicine involves the use of different plant extracts or the bioactive constituents. This type of study provides the health application at affordable cost. This study such as ethnomedicine keenly represents one of the best avenues in searching new economic plants for medicine. In keeping this view in mind the present investigation is carried out in Nerium oleander and Momordica charantia leaves. Qualitative phytochemical analysis of these two plants confirms the presence of various phytochemicals like carbohydrates, cholesterol, protein, amino acid, alkaloid, flavonoids, tannins, saponins, cardiac glycosides, terpenoids, and phlobatinins in their aqueous leaf extracts leaves followed by ethanol, ethyl acetate, diethyl ether and chloroform. The results suggest that the phytochemical properties of the leaves for curing various ailments and possess potential antioxidant properties.

  8. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

    OpenAIRE

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2015-01-01

    While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal dif...

  9. Tree and tree-like species of Mexico: gymnosperms, monocotyledons, and tree ferns Especies arbóreas y arborescentes de México: gimnospermas, monocotiledóneas y helechos arborescentes

    OpenAIRE

    Martin Ricker; Hernández, Héctor M.

    2010-01-01

    Trees or tree-like plants are defined here broadly as perennial, self-supporting plants with an adult height of at least 5 m (without ascending leaves or inflorescences), and with 1 or several erect stems with a diameter of at least 10 cm. We present an updated list of all Mexican tree species under that definition in the Gymnospermae (86 species, 38% endemic to Mexico), Monocotyledonae (75 species, 55% endemic), and Pteridophyta (9 species, none endemic). The list contains a total of 170 spe...

  10. Cisgenic apple trees; development, characterization and performance

    Directory of Open Access Journals (Sweden)

    Frans A. Krens

    2015-04-01

    Full Text Available Two methods were developed for the generation of cisgenic apples. Both have been successfully applied producing trees. The first method avoids the use of any foreign selectable marker genes; only the gene-of-interest is integrated between the T-DNA border sequences. The second method makes use of recombinase-based marker excision. For the first method we used the MdMYB10 gene from a red-fleshed apple coding for a transcription factor involved in regulating anthocyanin biosynthesis. Red plantlets were obtained and presence of the cisgene was confirmed. Plantlets were grafted and grown in a greenhouse. After three years, the first flowers appeared, showing red petals. Pollination led to production of red-fleshed cisgenic apples. The second method used the pM(arkerF(ree vector system, introducing the scab resistance gene Rvi6, derived from apple. Agrobacterium-mediated transformation, followed by selection on kanamycin, produced genetically modified apple lines. Next, leaves from in vitro material were treated to activate the recombinase leading to excision of selection genes. Subsequently, the leaf explants were subjected to negative selection for marker-free plantlets by inducing regeneration on medium containing 5-fluorocytosine. After verification of the marker-free nature, the obtained plants were grafted onto rootstocks. Young trees from four cisgenic lines and one intragenic line, all containing Rvi6, were planted in an orchard. Appropriate controls were incorporated in this trial. We scored scab incidence for three consecutive years on leaves after inoculations with Rvi6-avirulent strains. One cisgenic line and the intragenic line performed as well as the resistant control. In 2014 trees started to overcome their juvenile character and formed flowers and fruits. The first results of scoring scab symptoms on apple fruits were obtained. Apple fruits from susceptible controls showed scab symptoms, while fruits from cisgenic and intragenic

  11. Covering R-trees

    CERN Document Server

    Berestovskii, V N

    2007-01-01

    We show that every inner metric space X is the metric quotient of a complete R-tree via a free isometric action, which we call the covering R-tree of X. The quotient mapping is a weak submetry (hence, open) and light. In the case of compact 1-dimensional geodesic space X, the free isometric action is via a subgroup of the fundamental group of X. In particular, the Sierpin'ski gasket and carpet, and the Menger sponge all have the same covering R-tree, which is complete and has at each point valency equal to the continuum. This latter R-tree is of particular interest because it is "universal" in at least two senses: First, every R-tree of valency at most the continuum can be isometrically embedded in it. Second, every Peano continuum is the image of it via an open light mapping. We provide a sketch of our previous construction of the uniform universal cover in the special case of inner metric spaces, the properties of which are used in the proof.

  12. Steiner trees in industry

    CERN Document Server

    Du, Ding-Zhu

    2001-01-01

    This book is a collection of articles studying various Steiner tree prob­ lems with applications in industries, such as the design of electronic cir­ cuits, computer networking, telecommunication, and perfect phylogeny. The Steiner tree problem was initiated in the Euclidean plane. Given a set of points in the Euclidean plane, the shortest network interconnect­ ing the points in the set is called the Steiner minimum tree. The Steiner minimum tree may contain some vertices which are not the given points. Those vertices are called Steiner points while the given points are called terminals. The shortest network for three terminals was first studied by Fermat (1601-1665). Fermat proposed the problem of finding a point to minimize the total distance from it to three terminals in the Euclidean plane. The direct generalization is to find a point to minimize the total distance from it to n terminals, which is still called the Fermat problem today. The Steiner minimum tree problem is an indirect generalization. Sch...

  13. The inference of gene trees with species trees.

    Science.gov (United States)

    Szöllősi, Gergely J; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

    2015-01-01

    This article reviews the various models that have been used to describe the relationships between gene trees and species trees. Molecular phylogeny has focused mainly on improving models for the reconstruction of gene trees based on sequence alignments. Yet, most phylogeneticists seek to reveal the history of species. Although the histories of genes and species are tightly linked, they are seldom identical, because genes duplicate, are lost or horizontally transferred, and because alleles can coexist in populations for periods that may span several speciation events. Building models describing the relationship between gene and species trees can thus improve the reconstruction of gene trees when a species tree is known, and vice versa. Several approaches have been proposed to solve the problem in one direction or the other, but in general neither gene trees nor species trees are known. Only a few studies have attempted to jointly infer gene trees and species trees. These models account for gene duplication and loss, transfer or incomplete lineage sorting. Some of them consider several types of events together, but none exists currently that considers the full repertoire of processes that generate gene trees along the species tree. Simulations as well as empirical studies on genomic data show that combining gene tree-species tree models with models of sequence evolution improves gene tree reconstruction. In turn, these better gene trees provide a more reliable basis for studying genome evolution or reconstructing ancestral chromosomes and ancestral gene sequences. We predict that gene tree-species tree methods that can deal with genomic data sets will be instrumental to advancing our understanding of genomic evolution.

  14. Arginine, scurvy and Cartier's "tree of life"

    Directory of Open Access Journals (Sweden)

    Durzan Don J

    2009-02-01

    Full Text Available Abstract Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compounds were also probably present in decoctions prepared in the severe winter. The semi-essential arginine, proline and all the essential amino acids, would have provided additional nutritional benefits for the rapid recovery from scurvy by vitamin C when food supply was limited. The value of arginine, especially in the recovery of the critically ill sailors, is postulated as a source of nitric oxide, and the arginine-derived guanidino compounds as controlling factors for the activities of different nitric oxide synthases. This review provides further insights into the use of the candidate "trees of life" by indigenous peoples in eastern Canada. It raises hypotheses on the nutritional and synergistic roles of arginine, its metabolites, and other biofactors complementing the role of vitamin C especially in treating Cartier's critically ill sailors.

  15. Determinação da matéria seca e teores de macronutrientes em folhas de frutíferas usando diferentes métodos de secagem Determination of dry matter and macronutrient content in leaves of fruit trees using different drying methods

    Directory of Open Access Journals (Sweden)

    Nericlenes Chaves Marcante

    2010-11-01

    Full Text Available O objetivo desse estudo foi avaliar diferentes métodos de secagem de folhas para três diferentes frutíferas (maracujá, pêssego e abacate, com relação à determinação da matéria seca e os teores foliares de macronutrientes. Foram coletadas amostras de folhas recém expandida de três culturas, do pomar da fazenda de ensino e pesquisa da FCAV-UNESP, câmpus de Jaboticabal, no mês de janeiro de 2010, coletando-se para cada cultura 12 amostras com 25 folhas cada. Os tratamentos constituíram-se por dois métodos de secagem, estufa de circulação de ar forçada regulada a uma temperatura de 70°C e o forno microondas (FMO. Avaliou-se a massa da matéria seca e os teores foliares de macronutrientes. Os resultados sugerem que os dois métodos de secagem testados se assemelham na determinação de matéria seca e nos teores foliares de macronutrientes para as culturas análisadas, exceto os teores de cálcio na cultura do pêssego.The objective of this study was to evaluate different methods of drying of leaves for three different fruit (passion fruit, peach and avocado, with respect to the determination of dry matter and foliar nutrients. Samples were collected from recently expanded leaves of three crops orchard Farm education and research FCAV-UNESP, Jaboticabal campus, in January 2010, by collecting 12 samples for each culture with 25 leaves. The treatments consisted of two drying methods, greenhouse circulation of air regulated to a temperature of 70°C and FMO. We evaluated the mass of dry matter and foliar nutrients. The results suggest that the two drying methods tested did not interfere in the determination of dry matter and foliar nutrients to crops analyzed, except the calcium levels in peach.

  16. 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.

  17. Detection Performance of M-ary Relay Trees with Non-binary Message Alphabets

    CERN Document Server

    Zhang, Zhenliang; Pezeshki, Ali; Moran, William; Howard, Stephen D

    2012-01-01

    We study the detection performance of $M$-ary relay trees, where only the leaves of the tree represent sensors making measurements. The root of the tree represents the fusion center which makes an overall detection decision. Each of the other nodes is a relay node which aggregates $M$ messages sent by its child nodes into a new compressed message and sends the message to its parent node. Building on previous work on the detection performance of $M$-ary relay trees with binary messages, in this paper we study the case of non-binary relay message alphabets. We characterize the exponent of the error probability with respect to the message alphabet size $\\mathcal D$, showing how the detection performance increases with $\\mathcal D$. Our method involves reducing a tree with non-binary relay messages into an equivalent higher-degree tree with only binary messages.

  18. Drag reduction by reconfiguration of a full tree in a wind tunnel

    Science.gov (United States)

    de Langre, Emmanuel; Tadrist, Loic; Leclercq, Tristan; Hemon, Pascal; Amandolese, Xavier; Saudreau, Marc; Marquier, Andre; Knapp, Graham; Flamand, Olivier

    2015-11-01

    The results of drag measurements performed on a full 3 m-tall cherry tree in an atmospheric wind tunnel are presented. The drag on the trunk alone is shown to increase quadratically with the velocity of the flow, as expected, but the drag on the whole tree with branches and leaves follows a smaller power law with velocity, after the reconfiguration of most leaves. The transition from the quadratic law to a linear increase of the drag of the leaves with the magnitude of the flow is observed. Data is also obtained on moment loading on the base of the tree showing also an effect of the reconfiguration. Finally, these results are compared with current models of drag reduction by reconfiguration.

  19. Generic Ising trees

    DEFF Research Database (Denmark)

    Durhuus, Bergfinnur Jøgvan; Napolitano, George Maria

    2012-01-01

    The Ising model on a class of infinite random trees is defined as a thermodynamiclimit of finite systems. A detailed description of the corresponding distribution of infinite spin configurations is given. As an application, we study the magnetization properties of such systems and prove that they......The Ising model on a class of infinite random trees is defined as a thermodynamiclimit of finite systems. A detailed description of the corresponding distribution of infinite spin configurations is given. As an application, we study the magnetization properties of such systems and prove...... that they exhibit no spontaneous magnetization. Furthermore, the values of the Hausdorff and spectral dimensions of the underlying trees are calculated and found to be, respectively,¯dh =2 and¯ds = 4/3....

  20. Active flows on trees

    CERN Document Server

    Forrow, Aden; Dunkel, Jörn

    2016-01-01

    Coherent, large scale dynamics in many nonequilibrium physical, biological, or information transport networks are driven by small-scale local energy input. We introduce and explore a generic model for compressible active flows on tree networks. In contrast to thermally-driven systems, active friction selects discrete states with only a small number of oscillation modes activated at distinct fixed amplitudes. This state selection interacts with graph topology to produce different localized dynamical time scales in separate regions of large networks. Using perturbation theory, we systematically predict the stationary states of noisy networks and find good agreement with a Bayesian state estimation based on a hidden Markov model applied to simulated time series data on binary trees. While the number of stable states per tree scales exponentially with the number of edges, the mean number of activated modes in each state averages $\\sim 1/4$ the number of edges. More broadly, these results suggest that the macrosco...

  1. Effect of mixing low palatable grasses and ipil ipil leaves on forage quality

    International Nuclear Information System (INIS)

    The study was conducted at the National Agricultural Research Centre, Islamabad, Pakistan to investigate the impact of mixing low palatable grasses namely Heteropogon contortus, Desmostachya bipinnata, Sorghum halepense and Chrysopogon aucheri with tree leaves of Leucaena leucocephala (Ipil ipil) in the ratio of 75:25, 50:50, 25:75, along with sole species on their chemical composition. Samples were analyzed for proximate parameters (crude protein (CP), crude fiber (CF), total ash and ether extract (EE)). The results revealed that there were significant differences in dry matter (DM) among different grasses. DM content of low palatable grasses was generally high (70-75%) as compared to Ipil ipil leaves (45-55%). DM content among mixtures was also variable. For the treatment grass 75% + Ipil ipil 25%, DM range was 65-70%, for grass 50% + Ipil ipil 50%, it was 60-65% and for grass 25% + Ipil ipil 75%, it was 55%. The CP value of the treatments showed significant variation ranging from less than 10% in grasses to almost 30% in pure Ipil ipil leaves. The mixtures had CP content corresponding to proportions of grasses and legume tree leaves. The CF values also varied significantly among the treatments. Grasses had in general higher CF content than legume leaves. It can be concluded that addition of Ipil ipil leaves to grasses improved overall nutrition especially CP of the feed. (author)

  2. Why Do Some Evergreen Species Keep Their Leaves for a Second Winter, While Others Lose Them?

    Directory of Open Access Journals (Sweden)

    Peter J. Grubb

    2014-10-01

    Full Text Available In subtropical montane semi-moist forest in SW China (SMSF, a large majority of evergreen tree and tall shrub species was found to have only one cohort of old leaves in early spring. In contrast, almost all species of evergreen tree and tall shrub in warm temperate rain forest (WTRF in Japan and sclerophylls in Mediterranean-climate forest (MSF of the Mediterranean Basin have two or more cohorts of old leaves in early spring; they drop their oldest cohort during or soon after leaf outgrowth in spring. Japanese WTRF has no dry season and MSF a dry summer. SMSF has a dry winter. On four evergreen Rhododendron species from SW China with only one cohort of old leaves in spring when in cultivation in Scotland, the majority of leaves in the senescing cohort fell by the end of December. We hypothesize that with dry winters, there is an advantage to dropping older leaves in autumn, because there is a low chance of appreciable positive assimilation in winter and a high chance of desiccation, reducing the resorption of dry mass and mineral nutrients from ageing leaves. Our hypothesis may be extended to cover evergreens at high altitude or high latitude that experience cold soils in winter.

  3. Implications of multipurpose tree leaf application on wheat productivity in dry tropics

    Institute of Scientific and Technical Information of China (English)

    Rajani Srivastava; K. P. Singh

    2013-01-01

    Leaves of multipurpose tree species (those providing more than one function or product of human use) can serve as sources of fer-tilizer for nutrient supply, especially nitrogen (N). In this study chopped leaves of tropical tree species (5 N-fixing species, 5 non-N-fixing species and combinations of 5 N-fixing with a non-N-fixing species) were in-corporated in soil to evaluate its effects on wheat biological productivity (including grain yield, GYIELD) under dryland conditions. High quality leaves of N-fixing tree species (e.g. Dalbergia sissoo, Cassia fistula and Prosopis cineraria) had lower carbon/nitrogen (C/N), lignin/nitrogen (LIG/N), polyphenol/nitrogen (PPL/N) and lignin+polyphenol /nitrogen (LIG+PPL/N) ratios than low quality leaves of non-N-fixing species. Com-bination treatments had intermediate values of different parameters. Application of high quality leaves caused greater increases in wheat productivity and yield than other species. By the application of leaves of N-fixing trees, on average, wheat yield increased 160% relative to the control (no addition of leaves), and when combined with non-N-fixing Terminalia chebula leaves the yield increased 108%. Mean total net productivity (TNP) with N-fixing species treatments, exceeded mean TNP with non-N-fixing species and combination treatments by 50%and 28%, respectively. Multivariate regressions indicated that nitrogen (N) concen-tration in leaves (main nutrient), interacting with lignin (LIG) and poly-phenol (PPL) concentrations, explained 79%−86% of variability in pro-ductivity parameters and yield. Strong correlation between LIG+PPL/N ratio of leaves with GYIELD of wheat crop suggests that the ratio can be used as a reliable index for mass screening of multipurpose tree species for use as soil amendments especially in dryland agriculture. Direct ap-plication of high quality N-fixing tree species leaves (especially D. sissoo, C fistula and P. cineraria), an uncommon practice in dry tropics in India

  4. The Urban Environment Can Modify Drought Stress of Small-Leaved Lime (Tilia cordata Mill. and Black Locust (Robinia pseudoacacia L.

    Directory of Open Access Journals (Sweden)

    Astrid Moser

    2016-03-01

    Full Text Available The urban environment characterized by various stresses poses challenges to trees. In particular, water deficits and high temperatures can cause immense drought stress to urban trees, resulting in reduced growth and die-off. Drought-tolerant species are expected to be resilient to these conditions and are therefore advantageous over other, more susceptible species. However, the drought tolerance of urban trees in relation to the specific growth conditions in urban areas remains poorly researched. This study aimed to analyze the annual growth and drought tolerance of two common urban tree species, namely small-leaved lime (Tilia cordata Mill. (T. cordata and black locust (Robinia pseudoacacia L. (R. pseudoacacia, in two cities in southern Germany in relation to their urban growing conditions. Marked growth reductions during drought periods and subsequent fast recovery were found for R. pseudoacacia, whereas T. cordata exhibited continued reduced growth after a drought event, although these results were highly specific to the analyzed city. We further show that individual tree characteristics and environmental conditions significantly influence the growth of urban trees. Canopy openness and other aspects of the surrounding environment (water supply and open surface area of the tree pit, tree size, and tree species significantly affect urban tree growth and can modify the ability of trees to tolerate the drought stress in urban areas. Sustainable tree planting of well adapted tree species to their urban environment ensures healthy trees providing ecosystem services for a high quality of life in cities.

  5. The gene tree delusion.

    Science.gov (United States)

    Springer, Mark S; Gatesy, John

    2016-01-01

    Higher-level relationships among placental mammals are mostly resolved, but several polytomies remain contentious. Song et al. (2012) claimed to have resolved three of these using shortcut coalescence methods (MP-EST, STAR) and further concluded that these methods, which assume no within-locus recombination, are required to unravel deep-level phylogenetic problems that have stymied concatenation. Here, we reanalyze Song et al.'s (2012) data and leverage these re-analyses to explore key issues in systematics including the recombination ratchet, gene tree stoichiometry, the proportion of gene tree incongruence that results from deep coalescence versus other factors, and simulations that compare the performance of coalescence and concatenation methods in species tree estimation. Song et al. (2012) reported an average locus length of 3.1 kb for the 447 protein-coding genes in their phylogenomic dataset, but the true mean length of these loci (start codon to stop codon) is 139.6 kb. Empirical estimates of recombination breakpoints in primates, coupled with consideration of the recombination ratchet, suggest that individual coalescence genes (c-genes) approach ∼12 bp or less for Song et al.'s (2012) dataset, three to four orders of magnitude shorter than the c-genes reported by these authors. This result has general implications for the application of coalescence methods in species tree estimation. We contend that it is illogical to apply coalescence methods to complete protein-coding sequences. Such analyses amalgamate c-genes with different evolutionary histories (i.e., exons separated by >100,000 bp), distort true gene tree stoichiometry that is required for accurate species tree inference, and contradict the central rationale for applying coalescence methods to difficult phylogenetic problems. In addition, Song et al.'s (2012) dataset of 447 genes includes 21 loci with switched taxonomic names, eight duplicated loci, 26 loci with non-homologous sequences that are

  6. The gene tree delusion.

    Science.gov (United States)

    Springer, Mark S; Gatesy, John

    2016-01-01

    Higher-level relationships among placental mammals are mostly resolved, but several polytomies remain contentious. Song et al. (2012) claimed to have resolved three of these using shortcut coalescence methods (MP-EST, STAR) and further concluded that these methods, which assume no within-locus recombination, are required to unravel deep-level phylogenetic problems that have stymied concatenation. Here, we reanalyze Song et al.'s (2012) data and leverage these re-analyses to explore key issues in systematics including the recombination ratchet, gene tree stoichiometry, the proportion of gene tree incongruence that results from deep coalescence versus other factors, and simulations that compare the performance of coalescence and concatenation methods in species tree estimation. Song et al. (2012) reported an average locus length of 3.1 kb for the 447 protein-coding genes in their phylogenomic dataset, but the true mean length of these loci (start codon to stop codon) is 139.6 kb. Empirical estimates of recombination breakpoints in primates, coupled with consideration of the recombination ratchet, suggest that individual coalescence genes (c-genes) approach ∼12 bp or less for Song et al.'s (2012) dataset, three to four orders of magnitude shorter than the c-genes reported by these authors. This result has general implications for the application of coalescence methods in species tree estimation. We contend that it is illogical to apply coalescence methods to complete protein-coding sequences. Such analyses amalgamate c-genes with different evolutionary histories (i.e., exons separated by >100,000 bp), distort true gene tree stoichiometry that is required for accurate species tree inference, and contradict the central rationale for applying coalescence methods to difficult phylogenetic problems. In addition, Song et al.'s (2012) dataset of 447 genes includes 21 loci with switched taxonomic names, eight duplicated loci, 26 loci with non-homologous sequences that are

  7. Estimation of Tree Lists from Airborne Laser Scanning Using Tree Model Clustering and k-MSN Imputation

    Directory of Open Access Journals (Sweden)

    Jörgen Wallerman

    2013-04-01

    Full Text Available Individual tree crowns may be delineated from airborne laser scanning (ALS data by segmentation of surface models or by 3D analysis. Segmentation of surface models benefits from using a priori knowledge about the proportions of tree crowns, which has not yet been utilized for 3D analysis to any great extent. In this study, an existing surface segmentation method was used as a basis for a new tree model 3D clustering method applied to ALS returns in 104 circular field plots with 12 m radius in pine-dominated boreal forest (64°14'N, 19°50'E. For each cluster below the tallest canopy layer, a parabolic surface was fitted to model a tree crown. The tree model clustering identified more trees than segmentation of the surface model, especially smaller trees below the tallest canopy layer. Stem attributes were estimated with k-Most Similar Neighbours (k-MSN imputation of the clusters based on field-measured trees. The accuracy at plot level from the k-MSN imputation (stem density root mean square error or RMSE 32.7%; stem volume RMSE 28.3% was similar to the corresponding results from the surface model (stem density RMSE 33.6%; stem volume RMSE 26.1% with leave-one-out cross-validation for one field plot at a time. Three-dimensional analysis of ALS data should also be evaluated in multi-layered forests since it identified a larger number of small trees below the tallest canopy layer.

  8. Decoupled leaf and stem economics in rain forest trees.

    Science.gov (United States)

    Baraloto, Christopher; Timothy Paine, C E; Poorter, Lourens; Beauchene, Jacques; Bonal, Damien; Domenach, Anne-Marie; Hérault, Bruno; Patiño, Sandra; Roggy, Jean-Christophe; Chave, Jerome

    2010-11-01

    Cross-species analyses of plant functional traits have shed light on factors contributing to differences in performance and distribution, but to date most studies have focused on either leaves or stems. We extend these tissue-specific analyses of functional strategy towards a whole-plant approach by integrating data on functional traits for 13 448 leaves and wood tissues from 4672 trees representing 668 species of Neotropical trees. Strong correlations amongst traits previously defined as the leaf economics spectrum reflect a tradeoff between investments in productive leaves with rapid turnover vs. costly physical leaf structure with a long revenue stream. A second axis of variation, the 'stem economics spectrum', defines a similar tradeoff at the stem level: dense wood vs. high wood water content and thick bark. Most importantly, these two axes are orthogonal, suggesting that tradeoffs operate independently at the leaf and at the stem levels. By simplifying the multivariate ecological strategies of tropical trees into positions along these two spectra, our results provide a basis to improve global vegetation models predicting responses of tropical forests to global change.

  9. Early fruit setting from tissue culture-derived mangosteen tree

    Directory of Open Access Journals (Sweden)

    Sompong Te-chato

    2004-05-01

    Full Text Available Vitro-plantlets of mangosteen derived from culturing young leaves were acclimatized in 1993. Small and large polybag seedlings were carefully raised under controlled environmental conditions until 1994 when they were ready to be transferred to the field. During this stage, morphological abnormalities of the seedlings were recorded. After transferring to the field for 5-6 years (1994-1999 at Yi Ngo District, Narathiwat Province and Klong Hoi Khong District, Songkhla Province, morphological characters of the plants were again observed in comparison with seed-derived plants. The results showed that tissue culture-derived plants were more bushy and started blooming 5 years after planting while the seed-derived plants still had tall canopy (not bushy and were not bearing fruit in the same period of time. However, the blooming of cultured plants did not give the fruit setting in the first blooming year. All flowers dropped off completely. Heavy fruit setting was observed in the following year (2000. Tissue culture trees had smaller but healthier leaves whereas seed-derived trees had pale yellowish green leaves. Fruit qualities in terms of total soluble solids (TSS and total acids (TA were not much different between the two types of these mangosteen trees.

  10. Uptake and Translocation of Manganese by Native Tree Species in a Constructed Wetland Treating Landfill Leachates

    Directory of Open Access Journals (Sweden)

    A. Snow

    2007-01-01

    Full Text Available A surface flow constructed wetland was used to treat stormwater runoff from surrounding watersheds which are comprised primarily of commercial properties and two former landfills. The uptake of manganese by red maple, white birch and red spruce trees growing under flooded soil conditions in the constructed wetland was compared to that of the same trees growing under well drained soil conditions in a nearby reference site. The seasonal variability of manganese and its distribution in different compartments of these trees (leaves, twigs, branches, trunk wood, trunk bark and roots were studied. The average manganese concentrations in the aboveground compartments of red maple, white birch and red spruce trees were within the range of manganese concentrations reported in the literature for these trees. The concentrations of manganese in the aboveground compartments of red maple, white birch and red spruce trees in the reference site were significantly greater than those in the constructed wetland (with the exception of manganese concentrations in the trunk wood of red maple trees because of the acidic soil conditions of the reference site. The percent distribution of manganese in the aboveground compartments of trees did not vary during the growing season. Higher concentrations of manganese were present in the trunk bark and either the leaves or twigs of species on both the constructed wetland and the reference site regardless of the sampling date.

  11. How to leave your job.

    Science.gov (United States)

    Gurden, Dean

    2016-08-10

    'Leaving a job is never a decision you should take lightly,' says Nick Simpson, CEO of health recruitment agency MSI Group. 'Every nursing professional has things about their job they find frustrating and daily tasks they may not necessarily enjoy doing, but it's important to consider the positive aspects of your current role before you make a decision.' PMID:27507390

  12. Tree-string duality

    International Nuclear Information System (INIS)

    After the termination of perturbative QCD tree evolution, colourless clusters are formed. Similarly, after the first generation cuts in the (classical) Artru-Mennessier string model, disconnected lengths of string result. The mass spectra of clusters and first generation strings are similar, and the similarity extends to the rapidity distributions as a function of mass. (author)

  13. Christmas Tree Category Manual.

    Science.gov (United States)

    Bowman, James S.; Turmel, Jon P.

    This manual provides information needed to meet the standards for pesticide applicator certification. Pests and diseases of christmas tree plantations are identified and discussed. Section one deals with weeds and woody plants and the application, formulation and effects of herbicides in controlling them. Section two discusses specific diseases…

  14. A Universal Phylogenetic Tree.

    Science.gov (United States)

    Offner, Susan

    2001-01-01

    Presents a universal phylogenetic tree suitable for use in high school and college-level biology classrooms. Illustrates the antiquity of life and that all life is related, even if it dates back 3.5 billion years. Reflects important evolutionary relationships and provides an exciting way to learn about the history of life. (SAH)

  15. The Sacred Tree.

    Science.gov (United States)

    Lethbridge Univ. (Alberta).

    Designed as a text for high school students and adults, this illustrated book presents ethical concepts and teachings of Native societies throughout North America concerning the nature and possibilities of human existence. The final component of a course in self-discovery and development, the book begins with the legend of the "Sacred Tree"…

  16. Multiscale singularity trees

    DEFF Research Database (Denmark)

    Somchaipeng, Kerawit; Sporring, Jon; Johansen, Peter;

    2007-01-01

    We propose MultiScale Singularity Trees (MSSTs) as a structure to represent images, and we propose an algorithm for image comparison based on comparing MSSTs. The algorithm is tested on 3 public image databases and compared to 2 state-of-theart methods. We conclude that the computational complexi...

  17. Nitrogen availability, leaf life span and nitrogen conservation mechanisms in leaves of tropical trees Disponibilidade de nitrogênio, longevidade foliar e mecanismos de conservação de nitrogênio em folhas de espécies arbóreas tropicais

    Directory of Open Access Journals (Sweden)

    Guilherme Nascimento Corte

    2009-12-01

    Full Text Available Evergreen species of temperate regions are dominant in low-nutrient soils. This feature is attributed to more efficient mechanisms of nutrient economy. Nevertheless, the cashew (Anacardium occidentale- Anacardiaceae, a deciduous species, is native to regions in Brazil with sandy soil, whilst the annatto (Bixa orellana- Bixaceae, classified as an evergreen species native to tropical America, grows spontaneously in regions with more humid soils. Evergreens contain robust leaves that can resist adverse conditions for longer. The physical aspects of the leaves and mechanisms of nutrient economy between the two species were compared, in order to verify whether the deciduous species had more efficient mechanisms that might explain its occurrence in regions of low soil fertility. The mechanisms of nitrogen economy were also compared for the two species at available concentrations of this nutrient. The following were analysed: (i leaf life span, (ii physical leaf characteristics (leaf mass per area, and rupture strain, (iii nitrogenous compounds (nitrogen, chlorophyll, and protein, (iv nitrogen conservation mechanisms (nitrogen resorption efficiency, resorption proficiency, and use efficiency, and (v nitrogen conservation mechanisms under different availability of this mineral. The higher values of leaf mass per area and leaf rupture strain found in A. occidentale were related to its longer leaf life span. A. occidentale showed lower concentrations of nitrogen and protein in the leaves than B. orellana. Under lower nitrogen availability, A. occidentale had higher nitrogen resorption proficiency, nitrogen use efficiency and leaf life span than B. orellana. These characteristics may contribute to the adaptation of this species to sandy soils with low nitrogen content.Perenifólias de clima temperado são dominantes em solos pouco férteis. Essa característica é atribuída a mecanismos mais eficientes de economia de nutrientes. O cajueiro (Anacardium

  18. A Suffix Tree Or Not a Suffix Tree?

    DEFF Research Database (Denmark)

    Starikovskaya, Tatiana; Vildhøj, Hjalte Wedel

    2015-01-01

    , in particular we do not require that S ends with a unique symbol. This corresponds to considering the more general definition of implicit or extended suffix trees. Such general suffix trees have many applications and are for example needed to allow efficient updates when suffix trees are built online. We prove...

  19. A Proactive Tree Recovery Mechanism for Resilient Overlay Multicast

    Directory of Open Access Journals (Sweden)

    Poorna Satyanarayana B.

    2012-06-01

    Full Text Available Overlay multicast constructs a multicast delivery tree among end hosts. An important problem for making overlay multicast more dependable is how to recover from node departures in order to minimize the disruption of service to those affected nodes. In this paper, we propose a proactive tree recovery mechanism to make the overlay multicast resilient to these failures and unexpected events. The salient feature of the approach is that rescue plans for multiple non-leaf nodes can work together for their respective children when they fail or leave at the same time. Extensive simulations demonstrate that our proactive approach can recover from node departures much faster than reactive methods, while the quality of trees restored and the cost of recovery are reasonable

  20. Bounds On The Disjunctive Total Domination Number Of A Tree

    Directory of Open Access Journals (Sweden)

    Henning Michael A.

    2016-02-01

    . A leaf of G is a vertex of degree 1, while a support vertex of G is a vertex adjacent to a leaf. We show that if T is a tree of order n with ℓ leaves and s support vertices, then 2(n−ℓ+3/5≤γtd(T≤(n+s−1/2$2(n - \\ell + 3/5 \\le \\gamma _t^d (T \\le (n + s - 1/2$ and we characterize the families of trees which attain these bounds. For every tree T, we show have γt(T/γtd(T<2$\\gamma _t (T/\\gamma _t^d (T < 2$ and this bound is asymptotically tight.

  1. Do Trees Have Personalities? Experiencing the Concepts of Texture and Form

    Science.gov (United States)

    Kosta, Timothy J.

    2012-01-01

    Nature is all around, and can be the inspiration for some excellent creations in the classroom. How can a teacher bring these rich natural elements into the art class? As the author was exploring a hiking trail, he came across a large piece of bark from an old oak tree. A strong wind began to blow through the trees, the leaves began to rustle and…

  2. An Assessment of Ecosystem Services Provided by Street Trees in Bangkok, Thailand

    OpenAIRE

    SOONSAWAD, NATTHANIJ

    2014-01-01

    This study focuses on the analysis of ecosystem services provided by green spaces in Bangkok, Thailand, as a potential tool to address urban and environmental problems there. The analyses are divided into two parts for achieving two objectives, 1) estimating the magnitude of ecosystem services provided by public street trees, and 2) examining the relationship between stable isotopic data of tree leaves and the environmental quality of Bangkok's streets. The findings could be used to identify ...

  3. Toxic hazards of the industrial atmospheric pollutant sulphur dioxide on tree crops

    OpenAIRE

    Rani, B Dr

    2009-01-01

    A study was conducted to assess the effect of the industrial atmospheric pollutant, sulphur dioxide on tree crops such as coconut. The area around the Travancore Titanium Products at Trivandrum district of Kerala State, India, concerned with the manufacture of titanium dioxide was selected as the experimental site. Coconut palm (Cocos nucifera L.)was selected as the test crop since it dominates the tree crops in the area. Chemical analysis of leaves and nuts were made to assess the extent of...

  4. Discrimination of five Tunisian cultivars by Mid Infra Red spectroscopy combined with chemometric analyses of olive Olea europaea leaves

    OpenAIRE

    Aouidi, F.; Dupuy, N.; Artaud, J.; Roussos, Sevastianos; Msallem, M.; Perraud Gaime, Isabelle; M. Hamdi

    2012-01-01

    The high biodiversity of olive tree and the economic needs require tools for the correct classification and identification of the different cultivars. Simple and rapid methods are in increasing demand. In the present work, FT-MIR spectroscopy associated to chemometric treatment is proposed as a direct and rapid tool to discriminate cultivars according to their olive leaves, a persistent tissue the whole year. A set of 75 samples of olive leaves representative of five Tunisian cultivars (Cheml...

  5. [Hydraulic limitation on photosynthetic rate of old Populus simonii trees in sandy soil of north Shaanxi Province].

    Science.gov (United States)

    Zuo, Li-Xiang; Li, Yang-Yang; Chen, Jia-Cun

    2014-06-01

    'Old and dwarf trees' on the loess plateau region mainly occurred among mature trees rather than among small trees. To elucidate the mechanism of tree age on 'old and dwarf trees' formation, taking Populus simonii, a tree species that accounted for the largest portion of 'old and dwarf trees' on the loess plateau, as an example, the growth, photosynthesis and hydraulic traits of P. simonii trees with different ages (young: 13-15 years, mid-aged: 31-34 years, and old: 49-54 years) were measured. The results showed that the dieback length increased, and net photosynthetic rate, stomatal conductance, transpiration rate, and whole plant hydraulic conductance decreased significantly with the increasing tree age. Both net photosynthetic rate and stomatal conductance measured at different dates were significantly and positively related to the whole plant hydraulic conductance, suggesting that the decreasing photosynthetic rate of old trees was possibly caused by the declined hydraulic conductance. Although the resistance to cavitation in stems and leaves was stronger in old trees than in young and mid-aged trees, there were no differences in midday native stem embolization degree and leaf hydraulic conductance based on the vulnerability curve estimation, suggesting that the increased hydraulic resistance of the soil-root system is probably the most important reason for decreasing the whole plant hydraulic conductance of old trees.

  6. Tree Formation Using Coordinate Method

    Directory of Open Access Journals (Sweden)

    Monika Choudhary

    2015-06-01

    Full Text Available In this paper we are introducing a new method of tree formation, we propose a coordinate based method by which we can store and access tree structures. As we know in NLP, parsing is the most important module. The output of this module is generally parsed trees. Currently, TAG (Tree Adjoining Grammar is widely used grammar due to its linguistic and formal nature. It is simply tree generating system. The unit structure used in TAG is structured trees. So we used our new method to store trees where we worked on English to Hindi language. We worked on different sentences from English to Hindi, our method is the easiest way to manipulate tree. We have implemented within small corpus and for finite number of structures and further can be extended in future.

  7. Tree Transduction Tools for Cdec

    Directory of Open Access Journals (Sweden)

    Austin Matthews

    2014-09-01

    Full Text Available We describe a collection of open source tools for learning tree-to-string and tree-to-tree transducers and the extensions to the cdec decoder that enable translation with these. Our modular, easy-to-extend tools extract rules from trees or forests aligned to strings and trees subject to different structural constraints. A fast, multithreaded implementation of the Cohn and Blunsom (2009 model for extracting compact tree-to-string rules is also included. The implementation of the tree composition algorithm used by cdec is described, and translation quality and decoding time results are presented. Our experimental results add to the body of evidence suggesting that tree transducers are a compelling option for translation, particularly when decoding speed and translation model size are important.

  8. Visual perception of tree forms

    Energy Technology Data Exchange (ETDEWEB)

    Muederrisoglu, Haldun; Eroglu, Engin; OEzkan, Suekran; Ak, Kivanc [Department of Landscape Architecture, Faculty of Forestry, Abant Izzet Baysal University, 81000, Duzce (Turkey)

    2006-06-15

    This study, made in the cities of Adapazari, Duzce, and Bolu, has three fundamental goals. The first one is the evaluation of visual quality and strength of each tree form, second is the determination of visual quality and strength of different tree forms next to each other, and the third goal of this study is determining the effects of personal characteristics to the perception of tree forms. To reach these three goals the semantic differential method was used to evaluate graphical visions of tree forms. According to the findings, trees with pyramid forms have the most effective visual quality and strength. Pyramid-formed tree combinations have higher visual quality and strength than mixed combinations do. At the same time personal characteristics are effective on the visual perception of tree forms. A strong relationship between the amount of area per person in the cities the participants live in and their visual perception of tree forms has been found. (author)

  9. Learning Stochastic Tree Edit Distance

    OpenAIRE

    Bernard, Marc; Habrard, Amaury; Sebban, Marc

    2006-01-01

    Trees provide a suited structural representation to deal with complex tasks such as web information extraction, RNA secondary structure prediction, or conversion of tree structured documents. In this context, many applications require the calculation of similarities between tree pairs. The most studied distance is likely the tree edit distance for which improvements in terms of complexity have been achieved during the last decade. However, this classic edit distance usually uses a priori fixe...

  10. Connected searching of weighted trees

    CERN Document Server

    Dereniowski, Dariusz

    2010-01-01

    In this paper we consider the problem of connected edge searching of weighted trees. It is shown that there exists a polynomial-time algorithm for finding optimal connected search strategy for bounded degree trees with arbitrary weights on the edges and vertices of the tree. The problem is NP-complete for general node-weighted trees (the weight of each edge is 1).

  11. Adjustable Chain Trees for Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Fonseca, Rasmus

    2012-01-01

    A chain tree is a data structure for changing protein conformations. It enables very fast detection of clashes and free energy potential calculations. A modified version of chain trees that adjust themselves to the changing conformations of folding proteins is introduced. This results in much...... tighter bounding volume hierarchies and therefore fewer intersection checks. Computational results indicate that the efficiency of the adjustable chain trees is significantly improved compared to the traditional chain trees....

  12. Stand Composition, Tree Proximity and Size Have Minimal Effects on Leaf Function of Coexisting Aspen and Subalpine Fir.

    Science.gov (United States)

    Rhodes, Aaron C; Barney, Trevor; St Clair, Samuel B

    2016-01-01

    Forest structural heterogeneity due to species composition, spatial relationships and tree size are widely studied patterns in forest systems, but their impacts on tree function are not as well documented. The objective of this study was to examine how stand composition, tree proximity relationships and tree size influence the leaf functional traits of aspen, an early successional species, and subalpine fir, a climax species. We measured foliar nutrients, nonstructural carbohydrates (aspen only), defense chemistry and xylem water potential of aspen and subalpine fir trees in three size classes growing in close proximity or independently from other trees under three stand conditions: aspen dominant, aspen-conifer mixed, and conifer dominant stands. Close proximity of subalpine fir to aspen reduced aspen's storage of starch in foliar tissue by 17% suggesting that competition between these species may have small effects on carbon metabolism in aspen leaves. Simple sugar (glucose + sucrose) concentrations in aspen leaves were slightly higher in larger aspen trees than smaller trees. However, no differences were found in stem water potential, foliar concentrations of nitrogen, phosphorus, or secondary defense chemicals of aspen or subalpine fir across the gradients of stand composition, tree proximity or tree size. These results suggest that mechanisms of coexistence allow both aspen and subalpine fir to maintain leaf function across a wide range of stand structural characteristics. For aspen, resource sharing through its clonal root system and high resource storage capacity may partially contribute to its functional stability in mixed aspen-conifer stands.

  13. A Class of Graceful Trees

    Institute of Scientific and Technical Information of China (English)

    孟凡洪; 苏耕; 杨继

    2000-01-01

    The present paper shows the coordinates of a tree and its vertices, defines a kind of Trees with Odd-Number Radiant Type (TONRT), deals with the gracefulness of TONRT by using the edge-moving theorem, and uses graceful TONRT to construct another class of graceful trees.

  14. The Hopi Fruit Tree Book.

    Science.gov (United States)

    Nyhuis, Jane

    Referring as often as possible to traditional Hopi practices and to materials readily available on the reservation, the illustrated booklet provides information on the care and maintenance of young fruit trees. An introduction to fruit trees explains the special characteristics of new trees, e.g., grafting, planting pits, and watering. The…

  15. PoInTree: A Polar and Interactive Phylogenetic Tree

    Institute of Scientific and Technical Information of China (English)

    Carreras Marco; Gianti Eleonora; Sartori Luca; Plyte Simon Edward; Isacchi Antonella; Bosotti Roberta

    2005-01-01

    PoInTree (Polar and Innteractive Tree) is an application that allows to build, visualize, and customize phylogenetic trees in a polar, interactive, and highly flexible view. It takes as input a FASTA file or multiple alignment formats. Phylogenetic tree calculation is based on a sequence distance method and utilizes the Neighbor Joining (NJ) algorithm. It also allows displaying precalculated trees of the major protein families based on Pfam classification. In PoInTree, nodes can be dynamically opened and closed and distances between genes are graphically represented.Tree root can be centered on a selected leaf. Text search mechanism, color-coding and labeling display are integrated. The visualizer can be connected to an Oracle database containing information on sequences and other biological data, helping to guide their interpretation within a given protein family across multiple species.The application is written in Borland Delphi and based on VCL Teechart Pro 6 graphical component (Steema software).

  16. Rituals, ceremonies and customs related to sacred trees with a special reference to the Middle East

    Directory of Open Access Journals (Sweden)

    Dafni Amots

    2007-07-01

    Full Text Available Abstract Tree worship is very common worldwide. This field study surveys the ceremonies and customs related to sacred trees in present-day Israel; it includes the results of interviews with 98 informants in thirty-one Arab, Bedouin, and Druze villages in the Galilee. The main results are: 1. Sacred trees were treated as another kind of sacred entity with all their metaphysical as well as physical manifestations. 2. There is not even one ceremony or custom that is peculiar only to a sacred tree and is not performed in other sacred places (such as a saint's grave or a mosque. 3. Few customs, such as: quarrel settling (= Sulkha, leaving objects to absorb the divine blessing and leaving objects for charity seem to be characteristic of this region, only. 4. In modern times, sacred trees were never recorded, in Israel, as centres for official religious ceremonies including sacrifices, nor as places for the performing of rites of passage. 5. There is some variation among the different ethnic groups: Kissing trees and worshipping them is more common among the Druze although carrying out burials under the tree, leaving water and rain-making ceremonies under them have not been recorded in this group. Passing judgments under the tree is more typical of the Bedouin in which the sacred trees were commonly used as a public social centre. Most of the customs surveyed here are known from other parts of the world. The differences between Muslims and Druze are related to the latter's belief in the transmigration of souls.

  17. 喀斯特山区9种常见树木叶片在防火期的阻火性分析%Fire Resistance of Leaves During Fire Prevention Period of Nine Common Tree Species in Karst Mountain Regions

    Institute of Scientific and Technical Information of China (English)

    梁琴; 陶建平; 邓锋; 王微; 方文; 何平

    2015-01-01

    Objective]Guizhou province of China is one of the most typical karst regions in the world,at the same time,its fire disturbance is highly representative in the national forest fires. With the fragile karst environment plus severe forest fire disturbance,the fire prevention is particularly important and urgent in the Karst mountain regions of Guizhou province. Among the many fire prevention measures,the biological firebreak with its versatile,and long-term advantage, has attracted much attention of scholars and managers. The primary task of biological firebreak is to select the appropriate pyrophyte ( the plants with good fire resistance) . However,there is few study focus on the pyrophyte selection for karst mountain regions. On the other hand,with regard to pyrophyte selection,there is no uniform evaluation method up to now. It’s necessary to select appropriate fire-resistant tree species which are also suitable for growing in karst mountain regions,[Method]we investigated 9 common tree species from karst mountain regions of northwest Guizhou. Based on the measurements of four leaf traits ( benzene -alcohol extract content,ash content,ignition time and heat value) during fire prevention period,we used the Principal Component Analysis ( PCA) ,combined with the Weighted-Technique for Order Preference by Similarity to an Ideal Solution ( W-TOPSIS) ,to analyze the fire resistance.[Result]The Viburnum foetidum var. ceanothoides’s and Castanea seguinii’s benzene-alcohol extractive content were 2. 12 and 1. 97 times higher than Murica nana’s; The ash content of M. nana’s and V. foetidum var. ceanothoides’were the highest,and Castanea seguinii’s,Vaccinium pseudorobustum ’s and Ligustrum quihoui ’s were the lowest; The ignition time of L. quihoui, Castanea seguinii and Cotoneaster glaucophyllus var. glaucophyllus were the longest, and Puracantha fortuneana, Cunninghamia lanceolata and Rhododendron simsii were the shortest;The highest heat value were

  18. Fringe trees, Crump-Mode-Jagers branching processes and $m$-ary search trees

    OpenAIRE

    Holmgren, Cecilia; Janson, Svante

    2016-01-01

    This survey studies asymptotics of random fringe trees and extended fringe trees in random trees that can be constructed as family trees of a Crump-Mode-Jagers branching process, stopped at a suitable time. This includes random recursive trees, preferential attachment trees, fragmentation trees, binary search trees and (more generally) $m$-ary search trees, as well as some other classes of random trees. We begin with general results, mainly due to Aldous (1991) and Jagers and Nerman (1984). T...

  19. Doubly robust survival trees.

    Science.gov (United States)

    Steingrimsson, Jon Arni; Diao, Liqun; Molinaro, Annette M; Strawderman, Robert L

    2016-09-10

    Estimating a patient's mortality risk is important in making treatment decisions. Survival trees are a useful tool and employ recursive partitioning to separate patients into different risk groups. Existing 'loss based' recursive partitioning procedures that would be used in the absence of censoring have previously been extended to the setting of right censored outcomes using inverse probability censoring weighted estimators of loss functions. In this paper, we propose new 'doubly robust' extensions of these loss estimators motivated by semiparametric efficiency theory for missing data that better utilize available data. Simulations and a data analysis demonstrate strong performance of the doubly robust survival trees compared with previously used methods. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27037609

  20. Tree farming. Traedjordbruk

    Energy Technology Data Exchange (ETDEWEB)

    Falk, B. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research)

    1992-07-01

    Fallowed land can initially provide very favourable conditions for tree farming, thus enabling rapid canopy closure and a short rotation period. There may be justification for fertilization, particularly close to the time of canopy closure. Heavy clay soils should be avoided on account of poor tree growth. Crosses of balsam poplar are easy to regenerate through cuttings. The plantation should either be done with small plants protected against damage by game, or with planting stems branched at the bottoms in spacing patterns that are not too dense (3.5x3.5 - 5x5m). Branches at the bottom help to avoid rubbing by deer. Drainage systems are clogged by tree roots and fields drained by subsurface drainage systems should be avoided. Open ditches are sufficient for the requirements of the trees. Selected clones of balsam poplar crosses may have great resistance against disease. However, they do not have a growth rhythm that is ideally suited to Swedish conditions. Further breeding is probably necessary. The main use for balsam poplar is expected to be in the manufacture of pulp, mechanical or chemical. Other uses are veneer, building, glulam and fuel. Under good conditions, height and diameter development suggests a very high production. In plantations with suitable spacing patterns, the economically optimum rotation time is 15-20 year and the plantation appears to withstand high demands for return on investments and price competition. Future activities should foremost be concentrated on development of additional clone material, investigations of wood quality and the establishment and following up of further production experiments. (48 refs., 6 figs., 7 tabs.).

  1. Tree farming; Traedjordbruk

    Energy Technology Data Exchange (ETDEWEB)

    Falk, B. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research

    1992-07-01

    Fallowed land can initially provide very favourable conditions for tree farming, thus enabling rapid canopy closure and a short rotation period. There may be justification for fertilization, particularly close to the time of canopy closure. Heavy clay soils should be avoided on account of poor tree growth. Crosses of balsam poplar are easy to regenerate through cuttings. The plantation should either be done with small plants protected against damage by game, or with planting stems branched at the bottoms in spacing patterns that are not too dense (3.5x3.5 - 5x5m). Branches at the bottom help to avoid rubbing by deer. Drainage systems are clogged by tree roots and fields drained by subsurface drainage systems should be avoided. Open ditches are sufficient for the requirements of the trees. Selected clones of balsam poplar crosses may have great resistance against disease. However, they do not have a growth rhythm that is ideally suited to Swedish conditions. Further breeding is probably necessary. The main use for balsam poplar is expected to be in the manufacture of pulp, mechanical or chemical. Other uses are veneer, building, glulam and fuel. Under good conditions, height and diameter development suggests a very high production. In plantations with suitable spacing patterns, the economically optimum rotation time is 15-20 year and the plantation appears to withstand high demands for return on investments and price competition. Future activities should foremost be concentrated on development of additional clone material, investigations of wood quality and the establishment and following up of further production experiments. (48 refs., 6 figs., 7 tabs.).

  2. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  3. Tree Interpolation in Vampire

    OpenAIRE

    McMillan, Ken; Middeldorp, Aart; Voronkov, Andrei; Blanc, Régis; Gupta, Ashutosh; Kovács, Laura; Kragl, Bernhard

    2013-01-01

    We describe new extensions of the Vampire theorem prover for computing tree interpolants. These extensions generalize Craig interpolation in Vampire, and can also be used to derive sequence interpolants. We evaluated our implementation on a large number of examples over the theory of linear integer arithmetic and integer-indexed arrays, with and without quantifiers. When compared to other methods, our experiments show that some examples could only be solved by our implementation.

  4. Finding a Forest in a Tree

    DEFF Research Database (Denmark)

    Bacci, Giorgio; Miculan, Marino; Rizzi, Romeo

    2014-01-01

    by instantiating variables in yi with terms using variables from xj, for a different j; etc. In order to apply a wide reaction rule, we have to find a matching of the rule redex within the global state. This problem can be restated as follows: how to match a given forest (the redex) inside an unordered tree (the...... system), possibly finding the subtrees to be grafted at the forest’s leaves (i.e., instantiating the variables)? We show that, although the problem is NP-complete in general, the exponential explosion depends only on the number n of roots of the forest (the width of the redex), and not on the size...

  5. Changes of main secondary metabolites in leaves of Ginkgo biloba in response to ozone fumigation

    Institute of Scientific and Technical Information of China (English)

    HE Xingyuan; HUANG Wei; CHEN Wei; DONG Tian; LIU Changbing; CHEN Zhenju; XU Sheng; RUAN Yanan

    2009-01-01

    To investigate the effect of elevated O3 on the accumulation of main secondary metabolites in leaves of Ginkgo biloba L., four-year-old trees were exposed in open-top chambers with ambient air and the air with twice ambient O3 concentration in Shenyang in 2006.Elevated O3 increased the concentrations of terpenes, but decreased the concentrations of phenolics in G.biloba leaves.The results showed that secondary compounds from G.biloba leaves responded to the elevated O3 exposure in a different way when compared to previous studies which showed elevated O3 increased the concentrations of phenolics but had no effect on the terpenes in leaves of other deciduous trees.Furthermore, reduced synthesis of phenolics may decrease the resistance of G.biloba to O3 and other environmental factors.On the other hand, the induced synthesis of terpenes may enhance the antioxidant abilities in G.biloba leaves at the end of O3 fumigation.

  6. Carnivorous leaves from Baltic amber.

    Science.gov (United States)

    Sadowski, Eva-Maria; Seyfullah, Leyla J; Sadowski, Friederike; Fleischmann, Andreas; Behling, Hermann; Schmidt, Alexander R

    2015-01-01

    The fossil record of carnivorous plants is very scarce and macrofossil evidence has been restricted to seeds of the extant aquatic genus Aldrovanda of the Droseraceae family. No case of carnivorous plant traps has so far been reported from the fossil record. Here, we present two angiosperm leaves enclosed in a piece of Eocene Baltic amber that share relevant morphological features with extant Roridulaceae, a carnivorous plant family that is today endemic to the Cape flora of South Africa. Modern Roridula species are unique among carnivorous plants as they digest prey in a complex mutualistic association in which the prey-derived nutrient uptake depends on heteropteran insects. As in extant Roridula, the fossil leaves possess two types of plant trichomes, including unicellular hairs and five size classes of multicellular stalked glands (or tentacles) with an apical pore. The apices of the narrow and perfectly tapered fossil leaves end in a single tentacle, as in both modern Roridula species. The glandular hairs of the fossils are restricted to the leaf margins and to the abaxial lamina, as in extant Roridula gorgonias. Our discovery supports current molecular age estimates for Roridulaceae and suggests a wide Eocene distribution of roridulid plants. PMID:25453067

  7. Somatic Embryogenesis Induction and Plant Regeneration in Strawberry Tree (Arbutus unedo L.).

    Science.gov (United States)

    Martins, João F; Correia, Sandra I; Canhoto, Jorge M

    2016-01-01

    Somatic embryogenesis is a powerful tool both for cloning and studies of genetic transformation and embryo development. Most protocols for somatic embryogenesis induction start from zygotic embryos or embryonic-derived tissues which do not allow the propagation of elite trees. In the present study, a reliable protocol for somatic embryogenesis induction from adult trees of strawberry tree is described. Leaves from in vitro proliferating shoots were used to induce somatic embryo formation on a medium containing an auxin and a cytokinin. Somatic embryos germinated in a plant growth regulator-free medium.

  8. Morphological variability of leaves of Sorbus torminalis (L. Crantz in Poland

    Directory of Open Access Journals (Sweden)

    Leszek Bednorz

    2011-04-01

    Full Text Available This paper presents the results of the study on morphological variability of leaves of a scattered tree species Sorbus torminalis (L. Crantz in Poland. The leaves from short- and long shoots were collected from 17 localities widespread within the range of the species in Poland. Leaves were measured according to 15 morphological traits. The biometric data were subjected to multivariate statistical analysis in attempt to define variability between local populations. Most of the leaf traits are significantly correlated and are characterised by moderate level of variation. The average among population component of variation was 32.82% and 27.46% for leaves on short- and long shoots, respectively. The differences between sampled populations are significant, but only a weak geographical pattern of this differentiation was detected. Clinal type of variation was ascertained in two traits. Leaf traits which discriminate best the studied populations are also indicated. It was proved that leaves on short shoots differ markedly in shape and size from those of long shoots. Leaves on long shoots are steadier, but morphological trait values are less correlated. The study also confirmed the occurrence of individuals with leaves characteristic for S. torminalis var. perincisa Borbas et Feck and S. torminalis f. mollis Beck in a few Polish populations.

  9. Sequence Determination of a Novel Tripeptide Isolated from the Young Leaves of Azadirachta indica A. Juss

    Directory of Open Access Journals (Sweden)

    M. Rajeswari Prabha

    2013-01-01

    Full Text Available The neem tree has long been recognized for its unique properties, both against insects and in improving human health. Every part of the tree has been used as a traditional medicine for household remedy against various human ailments, from antiquity. Although the occurrence of various phytochemicals in neem has been studied, we have identified the presence of a novel tripeptide in the young leaves of neem using a simple and inexpensive paper chromatographic method, detected by Cu(II-ninhydrin reagent. The peptide nature of the isolated compound is confirmed by spectral studies. The sequence of the peptide is determined using de novo sequencing by tandem MS after purification.

  10. Pushdown machines for the macro tree transducer

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1986-01-01

    The macro tree transducer can be considered as a system of recursive function procedures with parameters, where the recursion is on a tree (e.g., the syntax tree of a program). We investigate characterizations of the class of tree (tree-to-string) translations which is induced by macro tree transduc

  11. Chemical constituents and antioxidant activity of the essential oil from leaves of Annona vepretorum Mart. (Annonaceae)

    OpenAIRE

    Camila de Souza Araújo; Ana Paula de Oliveira; Rafaely Nascimento Lima; Péricles Barreto Alves; Tâmara Coimbra Diniz; Jackson Roberto Guedes da Silva Almeida

    2015-01-01

    Background: Annona vepretorum (AV) is a native tree from Caatinga biome (semiarid region of Brazil) popularly known as “araticum” and “pinha da Caatinga.” Objective: This study was carried out to evaluate the chemical constituents and antioxidant activity (AA) of the essential oil from the leaves from AV (EO-Av) collected in Petrolina, Pernambuco, Brazil. Materials and Methods: Fresh leaves of AV were cut into pieces, and subjected to distillation for 2 h in a clevenger-type apparatus. Gas ch...

  12. Effect of N and NPK fertilizers on early field performance of narrow-leaved ash, Fraxinus angustifolia.

    Science.gov (United States)

    Cicek, Emrah; Yilmaz, Faruk; Yilmaz, Murat

    2010-01-01

    The effect of fertilization in the first growing season on early survival and growth of narrow-leaved ash (NLA) (Fraxinus angustifolia ssp. oxycarpa) was evaluated throughout the first 3 years of growth in Adapazari, Turkey. A randomized complete block design with four replications was established to investigate fertilization effects. Granular N urea [46%, (NH2)2CO, NH2-N] and NPK (15/15/15%; NH3-N, P2O5, K2O) fertilizers were applied in mid-May of the first growing season. Fertilization treatments per tree were control, 67 g NPK (equal to 10/10/10 g N/P2O5 /K2O tree(-1)), 133 g NPK (20/20/20 g N/P2O5 /K2O tree(-1)), 33 g urea N (15 g N tree(-1)) and 54 g urea N (25 g N tree(-1)). After three growing seasons under these fertilizer treatments, 98% of trees were still viable. Compared to the control treatment, fertilization had a large and positive effect on diameter and height growth during the first 3 years of growth. However, since there were no significant differences among the fertilized plots in terms of tree diameter and height growth, addition of P and K to the fertilizer regime was not beneficial. The results show that N fertilization in the first growing season has the potential to improve early field growth of narrow-leaved ash. PMID:20648820

  13. Smoking Leaves Lasting Marks on DNA: Study

    Science.gov (United States)

    ... fullstory_161060.html Smoking Leaves Lasting Marks on DNA: Study Changes related to disease found in more ... cigarettes can leave a lasting imprint on human DNA, altering more than 7,000 genes in ways ...

  14. Evolutionarily stable strategy of carbon and nitrogen investments in forest leaves and its application in vegetation dynamic modeling

    Science.gov (United States)

    Weng, E.; Farrior, C.; Dybzinski, R.; Pacala, S. W.

    2015-12-01

    Leaf mass per area (LMA) and leaf lifespan (LL) are two highly correlated plant traits that are key to plant physiological and ecological properties. Usually, low LMA means short LL, high nitrogen (N) content per unit mass, and fast turnover rates of nutrients; high LMA leads to long LL, low N content, and slow turnover rates. Deciduous trees with low LMA and short lifespan leaves have low carbon cost but high nitrogen demand; and evergreen trees, with high LMA and long lifespan leaves, have high carbon cost but low nitrogen demand. These relationships lead to: 1) evergreen trees have higher leaf area index than deciduous trees; 2) evergreen trees' carbon use efficiency is lower than the deciduous trees' because of their thick leaves and therefore high maintenance respiration; 3) the advantage of evergreens trees brought by their extra leaves over deciduous trees diminishes with increase N in ecosystem. These facts determine who will win when trees compete with each other in a N-limited ecosystem. In this study, we formulate a mathematical model according to the relationships between LMA, LL, leaf nitrogen, and leaf building and maintenance cost, where LMA is the fundamental variable determining the other three. We analyze the evolutionarily stable strategies (ESSs) of LMA with this mathematical model by examining the benefits of carbon and nitrogen investments to leaves in ecosystems with different N. The model shows the ESS converges to low LMA at high N and high LMA at low N. At intermediate N, there are two ESSs at low and high ends of LMA, respectively. The ESS also leads to low forest productivity by outcompeting the possible high productive strategies. We design a simulation scheme in an individual-based competition model (LM3-PPA) to simulate forest dynamics as results of the competition between deciduous and evergreen trees in three different biomes, which are temperate deciduous forest, deciduous-evergreen mixed forest, and boreal evergreen forest. The

  15. 香樟在徐州地区的引种及前景%Prospect of Growing Camphor Tree in Xuzhou Region

    Institute of Scientific and Technical Information of China (English)

    何树川

    2009-01-01

    Camphor tree has been widely used due to its unique characteritics of large and tall trunk, dense branches and leaves, large and shady canopy,magnificent tree form, long life cycle and evergreen. With global warming,scientific and technological progress and the improvement of plant cultivation techniques, the scope of planting Camphor tree is expanded. In this paper,the conditions and prospect of growing Camphor tree in Xuzhou were illustrated from aspects of biological characteristics,feasibility of growing the trees in Xuzhou, critical techniques of planting and tending..

  16. Eucalyptus Tree: A Potential Source of Cryptococcus neoformans in Egyptian Environment

    Directory of Open Access Journals (Sweden)

    Mahmoud Elhariri

    2016-01-01

    Full Text Available In Egypt, the River Red Gum (Eucalyptus camaldulensis is a well-known tree and is highly appreciated by the rural and urban dwellers. The role of Eucalyptus trees in the ecology of Cryptococcus neoformans is documented worldwide. The aim of this survey was to show the prevalence of C. neoformans during the flowering season of E. camaldulensis at the Delta region in Egypt. Three hundred and eleven samples out of two hundred Eucalyptus trees, including leaves, flowers, and woody trunks, were collected from four governorates in the Delta region. Thirteen isolates of C. neoformans were recovered from Eucalyptus tree samples (4.2%. Molecular identification of C. neoformans was done by capsular gene specific primer CAP64 and serotype identification was done depending on LAC1 gene. This study represents an update on the ecology of C. neoformans associated with Eucalyptus tree in Egyptian environment.

  17. Effects of open-top chambers on Valencia' orange trees. [Citrus sinensis

    Energy Technology Data Exchange (ETDEWEB)

    Olszyk, D.M. (Environmental Protection Agency, Corvallis, OR (United States)); Takemoto, B.K. (California Air Resources Board, Sacramento (United States)); Kats, G.; Dawson, P.J.; Morrison, C.L.; Preston, J.W.; Thompson, C.R. (Univ. of California, Riverside (United States))

    Open-top field chambers are the most widely used technology for evaluating the impacts of air pollutants on vegetation. This study was conducted to evaluate the long-term effects of chambers on Valencia orange trees (Citrus sinensis (L.) Osbeck). The trees were exposed to ambient ozone (O{sub 3}) for 51 months in large (4.3-m diam. by 2.9-m high) nonfiltered open-top chambers (NF) and in ambient air without chambers (AA). Results suggest that the yield increases for NF compared to AA trees could, in part, be accounted for by decreased flux of O{sub 3} into leaves (based on decreased O{sub 3} exposure and leaf conductance). However, other factors, i.e., increased tree growth, altered leaf C allocation, and lack of wind stress occurring only in chambers, likely contributed to higher NF tree yields.

  18. Eucalyptus Tree: A Potential Source of Cryptococcus neoformans in Egyptian Environment.

    Science.gov (United States)

    Elhariri, Mahmoud; Hamza, Dalia; Elhelw, Rehab; Refai, Mohamed

    2016-01-01

    In Egypt, the River Red Gum (Eucalyptus camaldulensis) is a well-known tree and is highly appreciated by the rural and urban dwellers. The role of Eucalyptus trees in the ecology of Cryptococcus neoformans is documented worldwide. The aim of this survey was to show the prevalence of C. neoformans during the flowering season of E. camaldulensis at the Delta region in Egypt. Three hundred and eleven samples out of two hundred Eucalyptus trees, including leaves, flowers, and woody trunks, were collected from four governorates in the Delta region. Thirteen isolates of C. neoformans were recovered from Eucalyptus tree samples (4.2%). Molecular identification of C. neoformans was done by capsular gene specific primer CAP64 and serotype identification was done depending on LAC1 gene. This study represents an update on the ecology of C. neoformans associated with Eucalyptus tree in Egyptian environment. PMID:26884765

  19. Pb and Cd Contents in Soil, Water, and Trees at an Afforestation Site, South China.

    Science.gov (United States)

    Pei, Nancai; Chen, Bufeng; Liu, Shuguang

    2015-11-01

    Pb and Cd contents in 13 plantation tree species (leaf and branch components), soil, water (groundwater and river water) at a young (3-5 year-old) seashore afforestation stand were investigated in Nansha district, Guangzhou city in southern China. The results showed that (1) soil, rather than water or trees, had the highest content of both Pb (averagely 48.79 mg/kg) and Cd (0.50 mg/kg), demonstrating that soil might function as a major reservoir for extraneously derived heavy metals; (2) Pb content was higher in branches than in leaves, but Cd content appeared similar in both components, implying possibly different accumulation mechanisms in trees; (3) Pb and Cd appeared to accumulate differently among some tree taxa, whereas almost no significant difference was detected between introduced and indigenous species. The study indicated that trees were potentially useful to remediate sites contaminated with Pb and Cd in the urbanized areas.

  20. 1-Skeletons of the Spanning Tree Problems with Additional Constraints

    Directory of Open Access Journals (Sweden)

    V. A. Bondarenko

    2015-01-01

    Full Text Available In this paper, we study polyhedral properties of two spanning tree problems with additional constraints. In the first problem, it is required to find a tree with a minimum sum of edge weights among all spanning trees with the number of leaves less than or equal to a given value. In the second problem, an additional constraint is the assumption that the degree of all nodes of the spanning tree does not exceed a given value. The recognition versions of both problems are NP-complete. We consider polytopes of these problems and their 1-skeletons. We prove that in both cases it is a NP-complete problem to determine whether the vertices of 1-skeleton are adjacent. Although it is possible to obtain a superpolynomial lower bounds on the clique numbers of these graphs. These values characterize the time complexity in a broad class of algorithms based on linear comparisons. The results indicate a fundamental difference between combinatorial and geometric properties of the considered problems from the classical minimum spanning tree problem.

  1. Hydraulic constraints modify optimal photosynthetic profiles in giant sequoia trees.

    Science.gov (United States)

    Ambrose, Anthony R; Baxter, Wendy L; Wong, Christopher S; Burgess, Stephen S O; Williams, Cameron B; Næsborg, Rikke R; Koch, George W; Dawson, Todd E

    2016-11-01

    Optimality theory states that whole-tree carbon gain is maximized when leaf N and photosynthetic capacity profiles are distributed along vertical light gradients such that the marginal gain of nitrogen investment is identical among leaves. However, observed photosynthetic N gradients in trees do not follow this prediction, and the causes for this apparent discrepancy remain uncertain. Our objective was to evaluate how hydraulic limitations potentially modify crown-level optimization in Sequoiadendron giganteum (giant sequoia) trees up to 90 m tall. Leaf water potential (Ψ l ) and branch sap flow closely followed diurnal patterns of solar radiation throughout each tree crown. Minimum leaf water potential correlated negatively with height above ground, while leaf mass per area (LMA), shoot mass per area (SMA), leaf nitrogen content (%N), and bulk leaf stable carbon isotope ratios (δ(13)C) correlated positively with height. We found no significant vertical trends in maximum leaf photosynthesis (A), stomatal conductance (g s), and intrinsic water-use efficiency (A/g s), nor in branch-averaged transpiration (E L), stomatal conductance (G S), and hydraulic conductance (K L). Adjustments in hydraulic architecture appear to partially compensate for increasing hydraulic limitations with height in giant sequoia, allowing them to sustain global maximum summer water use rates exceeding 2000 kg day(-1). However, we found that leaf N and photosynthetic capacity do not follow the vertical light gradient, supporting the hypothesis that increasing limitations on water transport capacity with height modify photosynthetic optimization in tall trees. PMID:27553681

  2. Hydraulic constraints modify optimal photosynthetic profiles in giant sequoia trees.

    Science.gov (United States)

    Ambrose, Anthony R; Baxter, Wendy L; Wong, Christopher S; Burgess, Stephen S O; Williams, Cameron B; Næsborg, Rikke R; Koch, George W; Dawson, Todd E

    2016-11-01

    Optimality theory states that whole-tree carbon gain is maximized when leaf N and photosynthetic capacity profiles are distributed along vertical light gradients such that the marginal gain of nitrogen investment is identical among leaves. However, observed photosynthetic N gradients in trees do not follow this prediction, and the causes for this apparent discrepancy remain uncertain. Our objective was to evaluate how hydraulic limitations potentially modify crown-level optimization in Sequoiadendron giganteum (giant sequoia) trees up to 90 m tall. Leaf water potential (Ψ l ) and branch sap flow closely followed diurnal patterns of solar radiation throughout each tree crown. Minimum leaf water potential correlated negatively with height above ground, while leaf mass per area (LMA), shoot mass per area (SMA), leaf nitrogen content (%N), and bulk leaf stable carbon isotope ratios (δ(13)C) correlated positively with height. We found no significant vertical trends in maximum leaf photosynthesis (A), stomatal conductance (g s), and intrinsic water-use efficiency (A/g s), nor in branch-averaged transpiration (E L), stomatal conductance (G S), and hydraulic conductance (K L). Adjustments in hydraulic architecture appear to partially compensate for increasing hydraulic limitations with height in giant sequoia, allowing them to sustain global maximum summer water use rates exceeding 2000 kg day(-1). However, we found that leaf N and photosynthetic capacity do not follow the vertical light gradient, supporting the hypothesis that increasing limitations on water transport capacity with height modify photosynthetic optimization in tall trees.

  3. LAI based trees selection for mid latitude urban developments: A microclimatic study in Cairo, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Fahmy, Mohamad [School of Architecture, University of Sheffield, Sheffield (United Kingdom); Department of Architecture, Military Technical College, Cairo (Egypt); Sharples, Stephen [School of Architecture, University of Sheffield, Sheffield (United Kingdom); Yahiya, Mahmoud [Department of Mechanical Engineering, University of Sheffield, Sheffield (United Kingdom); Mechanical Engineering Branch, Military Technical College, Cairo (Egypt)

    2010-02-15

    To study the leaf area index, LAI, based thermal performance in distinguishing trees for Cairo's urban developments, ENVI-met plants database was used as platform for a foliage modeling parameter, the leaf area density, LAD. Two Egyptian trees; Ficus elastica, and Peltophorum pterocarpum were simulated in 2 urban sites with one having no trees, whilst the second is having Ficus nitida trees. Trees LAD values were calculated using flat leaves' trees LAI definition to produce maximum ground solid shadow at peak time. An empirical value of 1 for LAI is applied to numerically introduce LAD values for ENVI-met. Basically, different meteorological records showed improvements for pedestrian comfort and ambient microclimate of the building using F. elastica. About 40-50% interception of direct radiation, reductions in surfaces' fluxes around trees and in radiant temperature T{sub mrt} in comparison to base cases gave preferability to F. elastica. The lack of soil water prevented evapotranspiration to take place effectively and the reduced wind speeds concluded negligible air temperature differences from both base cases except slightly appeared with the F. elastica. Results show that a flat leaves tree if does not validate LAI of 1, the ground shading would not fulfill about 50% direct radiation interception and this value can be used as a reference for urban trees selection. Further simulations were held to investigate LAI value of maximum direct radiation interception. Performing additional simulations, F. elastica of LAI of 3 intercepted almost 84% of direct radiation and revealed implications about urban trees in practice and its actual LAI. (author)

  4. MEMORY ENHANCING ACTIVITIES OF FICUS RELIGIOSA LEAVES IN RODENTS

    Directory of Open Access Journals (Sweden)

    Wangkhem Bandana Devi

    2011-03-01

    Full Text Available Ficus religiosa, a sacred tree to both Hindus and Buddhists, is recognized for its medicinal as well as religious purposes in India. The ethanolic extract prepared from the leaves of Ficus religiosa was studied for memory enhancing activities in Wistar albino rats and Swiss albino mice. The present study was carried out on five models such as Elevated-Plus Maze, Step through passive avoidance test, Sodium nitrite intoxication, Hebb-Williams Maze and Radial Arm Maze to evaluate learning and memory parameters. Scopolamine (1mg/kg, i.p was used as inducing agent in Elevated-plus maze, Step through passive avoidance test and sodium nitrite (95mg/kg, s.c was used as inducing agent in Sodium nitrite intoxication model. Piracetam (200mg/kg, i.p was used as standard nootropic agent for all the models except for Sodium nitrite intoxication; Mentat was used as positive control for Sodium nitrite intoxication model. The ethanolic extract of Ficus religiosa leaves significantly improved memory and reversed the amnesia induced by scopolamine and hypoxia induced by sodium nitrite. The ethanolic extract of Ficus religiosa leaves (100 mg/kg was comparable to that of piracetam (200 mg/kg and Mentat (100mg/kg. From the results of the present study it is concluded that the leaf extract of Ficus religiosa might possess anti-amnesic as well as nootropic properties. Also the major active constituents present in its leaves such as amino acids may be responsible for these activities.

  5. The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C-3 species

    NARCIS (Netherlands)

    Poorter, H; VanBerkel, Y; Baxter, R; DenHertog, J; Dijkstra, P; Gifford, RM; Griffin, KL; Roumet, C; Roy, J

    1997-01-01

    We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO2, These species comprised wild and agricultural herbaceous plants as well as tree seedlings, Both average responses a

  6. The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C3 species

    NARCIS (Netherlands)

    Poorter, H.; Berkel, Y. van; Baxter, B.; Hertog, J. den; Dijkstra, P.; Gifford, R.M.; Griffin, K.L.; Roumet, C.; Roy, J.; Wong, S.C.

    1997-01-01

    We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO₂. These species comprised wild and agricultural herbaceous plants as well as tree seedlings. Both average responses a

  7. Extraction of arbutin and its comparative content in branches, leaves, stems, and fruits of Japanese pear Pyrus pyrifolia cv. Kousui.

    Science.gov (United States)

    Sasaki, Chizuru; Ichitani, Masaki; Kunimoto, Ko-Ki; Asada, Chikako; Nakamura, Yoshitoshi

    2014-01-01

    Arbutin is a tyrosinase inhibitor and is extensively used as a human skin-whitening agent. This study investigated the optimum conditions for extracting arbutin by ultrasonic homogenization from discarded branches pruned from Japanese pear (Pyrus pyrifolia cv. Kousui) trees. The arbutin content was measured in the branches and also in the leaves, stems, fruit peel, and fruit flesh.

  8. Water supply and tree growth. Part I. Water deficits

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, T.T.

    1982-02-01

    Water supply is the most important environmental factor determining distribution, species composition and growth of forests. Net annual primary production of forests varies from as much as 3000 g/m/sub 2/ in wet regions to negligible amounts in dry regions. The water balance of trees has been characterized by visible wilting, tissue moisture content, relative water content, saturation deficit, and water potential. Water deficits develop readily in forest trees, even in trees growing in wet soil, because of excess transpiration over absorption of water. Water deficits adversely affect seed germination and cause shrinkage of leaves, stems, roots, fruits, and cones. Some of the decrease in photosynthesis during drought is the result of increased resistance to diffusion of CO/sub 2/ to chloroplasts and some to decrease in photosynthetic capacity. Water deficits inhibit shoot growth, wood production, and root growth. Yield of fruits and seeds can be inhibited at various stages of reproductive growth such as flower bud initiation, anthesis, pollination, fertilization, embryo growth, and fruit and seed enlargement. Water deficits may also induce leaf scorching and abscission, dieback of twigs and branches, and drought cracks. Severe water deficits often kill trees. Drought tolerance of trees may reflect desiccation avoidance or desiccation tolerance, with the former much more important. Among the most important of these are reduction in number and size of leaves; small, few, and sunken stomata; rapid stomatal closure; abundant leaf waxes; leaf shedding during droughts; extensive root development; capacity for twig and stem photosynthesis; living wood fibers; and strong development of palisade mesophyll.

  9. Morphometric characteristics of the leaves of Greek maple (Acer heldreichii Orph in central Serbia

    Directory of Open Access Journals (Sweden)

    Perović Marko

    2007-01-01

    Full Text Available The taxonomic characteristics of Greek maple (Acer heldreichii Orph were studied based on the analysis of leaf characteristics, by comparative-morphological method. The study was performed at three localities in central Serbia: Goč, Jastrebac and Rudnik. 30 normally developed trees were selected per each locality, and 30 leaves were selected from each tree for the analysis. The study includes 8 measured and 15 derived characteristics of leaves. The study results were statistically processed by correlation analysis, analysis of variance and cluster-analysis. It is concluded that there are two varieties, var. heldreichii and var. macropterum. Four forms are set aside in the variety macropterum: f. typicum f. dissectum, f. Equiloba and f. rotundiloba. The populations are relatively homogeneous, and both varieties occur at all three localities in significant numbers.

  10. Effect of tree-crop intercropping on a young Populus tomentosa plantation

    Institute of Scientific and Technical Information of China (English)

    JIANG Yuezhong; QIN Guanghua

    2007-01-01

    In order to study the effect of tree crop intercropping on a young plantation ofPopulus tomentosa in the plains along the Yellow River,field experiments were conducted by observing the growth of the plantation,the nutrient content in leaves,the nutrient and water content in the soil,and the output of crops.The relationship between forest growth and nutrient content in the tree leaves and the soil were analyzed.Results show that tree crop intercropping in young plantations can not only improve soil water content,but also enhance the contents of organic matter and the available nitrogen,phosphorus and potassium in soil resulting in the vigorous growth of the individual trees.Diameter at breast height (DBH) was positively related to the contents of organic matter in the soil,and the contents of N,P and K in the tree leaves had correlation coefficients of 0.967,0.955,0.988 and 0.972,respectively.Whole tree leaf area,crown width,number of branches and the mean length of branches in the intercropped plantation (intercropped with watermelon and vegetables,peanut and winter wheat,and soybean) were,respectively,1.70-3.0 times,2.22-2.47 times,1.0-1.41 times and 1.70-2.32 times of those of CK (without intercropping).Diameter at breast height (DBH) and tree height in the intercropped plantation were 50.5%-136.7% and 27%-59.5% higher than those of the CK,respectively.The study also showed that intercropping with watermelon and vegetables proved to have the highest economic return among the treatments adopted.Tree crop intercropping in young plantations is an effective measure to increase forest growth and economic benefit.

  11. Palm trees and islands – Current filaments in the edge of JET

    DEFF Research Database (Denmark)

    Maszl, Ch.; Naulin, Volker; Brix, M.;

    2011-01-01

    be conjectured that ELM filaments leave corresponding holes behind. If such a hole is able to reach a resonant magnetic surface it may close on itself and thus increase its lifetime significantly, thereby becoming detectable. We presume that the Palm Tree Mode (PTM) is a signature of such an event. Understanding...

  12. Resource capture by single leaves

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  13. Save a Tree

    Science.gov (United States)

    Williams, Kathryn R.

    1999-10-01

    Starting in September 1925, JCE reproduced pictures of famous chemists or chemistry-related works of art as frontispieces. Often, the Journal included a biography or other article about the picture. The August 1945 frontispiece featured the largest cork oak in the United States. An accompanying article described the goals of the Cork Project to plant cork trees in suitable locations in the U.S., to compensate for uncertain European and African sources during World War II. The final frontispiece appeared in December 1956. To view supplementary material, please refer to JCE Online's supplementary links.

  14. PHARMACOGNOSTIC AND PHYSICO- CHEMICAL EVALUATION OF LEAVES OF TECOMA GAUDICHAUDI DC (BIGNONIACEAE)

    OpenAIRE

    Kedar K.A; S. R. CHAUDHARI; A. Srinivasa Rao

    2013-01-01

    Tecoma gaudichaudi DC (Family Bignoniaceae) is a small tree of height 9-12m. and various Tecoma species are attractive to bees, butterflies or birds. Present study focuses on determination of some quantitative microscopical factors of leaves of Tecoma gaudichaudi DC includes Stomatal no., vein islet no etc. Under physicochemical standards various parameters were checked, such as ash value, acid insoluble ash value and moisture content etc. It helps in to check purity of crude drug. Ultimately...

  15. Dye-sensitized solar cells based on dyes extracted from dried plant leaves

    OpenAIRE

    Sofyan A. Taya; Taher M. El-Agez; ELREFI, Kamal S.

    2015-01-01

    In this work, natural dyes were extracted from dried plant leaves of plant cream, apricot, figs, apples, sage, thyme, mint, Ziziphus jujuba, orange, shade tree, basil, berry, Mirabelle plum, Victoria plum, peach, mango, pomegranate, banana, guava, and fluoridation-treated plant. The extracts were used as photosensitizers for dye-sensitized solar cells (DSSCs). The cells were assembled using nanostructured TiO2 films. The best performance was observed for the DSSC sensitized with Ziziphus juju...

  16. Characteristics of element composition of aerosols adsorbed on leaves by radioactivation analysis and their effects on plants

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, Takejiro; Koshikawa, Masami [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan); Sase, Hiroyuki; Masuzawa, Toshiyuki; Kawashima, Munetsugu; Takada, Jitsuya; Matsushita, Rokuji

    1999-01-01

    Aerosol deposits on leaves of various trees, especially cedar in different regions of Japan were collected to characterize the elemental composition using neutron activation analysis, ICP-AES, etc. and also investigate the effects of deposit aerosols on plants and the efficacy as an indicator for air pollution. Compared with the elemental composition of the soil, Se, Cr, Au, Br, As, Sb, Ag, etc. were more abundant in aerosols on cedar leaves. Especially, Sb is thought to be mostly derived from combustion of fossil fuels (exhaust gas from cars, etc.). Since Sb was accumulated on leaves at high levels and the analytical precision for Sb by neutron radioactivation was very high, the element was thought useful as an indicator for air pollution. If the amounts of Sb on the leaves of cedar and pine trees, which are widely distributed in Japan are determined, the degrees of pollution in all regions of Japan would be determined. In cedar trees of Saitama Prefecture where the deposit amounts of aerosols were comparatively larger, 42% of stoma was covered with the deposits, resulting that the rate of cuticular transpiration was increased and the amounts of basic elements leached from the leave surface was also increased. Thus, it was suggested that these changes might be the cause of recent declining of cedars in Japanese urban regions. (M.N.)

  17. Characteristics of element composition of aerosols adsorbed on leaves by radioactivation analysis and their effects on plants

    International Nuclear Information System (INIS)

    Aerosol deposits on leaves of various trees, especially cedar in different regions of Japan were collected to characterize the elemental composition using neutron activation analysis, ICP-AES, etc. and also investigate the effects of deposit aerosols on plants and the efficacy as an indicator for air pollution. Compared with the elemental composition of the soil, Se, Cr, Au, Br, As, Sb, Ag, etc. were more abundant in aerosols on cedar leaves. Especially, Sb is thought to be mostly derived from combustion of fossil fuels (exhaust gas from cars, etc.). Since Sb was accumulated on leaves at high levels and the analytical precision for Sb by neutron radioactivation was very high, the element was thought useful as an indicator for air pollution. If the amounts of Sb on the leaves of cedar and pine trees, which are widely distributed in Japan are determined, the degrees of pollution in all regions of Japan would be determined. In cedar trees of Saitama Prefecture where the deposit amounts of aerosols were comparatively larger, 42% of stoma was covered with the deposits, resulting that the rate of cuticular transpiration was increased and the amounts of basic elements leached from the leave surface was also increased. Thus, it was suggested that these changes might be the cause of recent declining of cedars in Japanese urban regions. (M.N.)

  18. The fault-tree compiler

    Science.gov (United States)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

    The Fault Tree Compiler Program is a new reliability tool used to predict the top event probability for a fault tree. Five different gate types are allowed in the fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N gates. The high level input language is easy to understand and use when describing the system tree. In addition, the use of the hierarchical fault tree capability can simplify the tree description and decrease program execution time. The current solution technique provides an answer precise (within the limits of double precision floating point arithmetic) to the five digits in the answer. The user may vary one failure rate or failure probability over a range of values and plot the results for sensitivity analyses. The solution technique is implemented in FORTRAN; the remaining program code is implemented in Pascal. The program is written to run on a Digital Corporation VAX with the VMS operation system.

  19. A study of metal distribution from lignite fuels using trees as biological monitors.

    Science.gov (United States)

    Sawidis, T; Chettri, M K; Papaioannou, A; Zachariadis, G; Stratis, J

    2001-01-01

    Concentrations of five metals (Cd, Cu, Mn, Fe, Zn) were determined in tree leaves collected from an area with large coal-fired plants in Ptolemais, Macedonia, Greece. The analyses were carried out with flame atomic absorption spectroscopy. Mean heavy metal content in the tree leaves is, in descending order, Fe>Mn>Zn>Cu>Cd. In Populus nigra and Salix babylonica the dense piled leaves and the widespread root system are the reasons for high heavy metal uptake. Conifer trees Pinus nigra and Juniperus arizona, which have a rough leaf surface, also had elevated concentrations. Leaves with a smooth surface were less contaminated. The presence of one metal within leaf cells may reduce the uptake or toxicity of other metals. Fruits accumulated less heavy metal than the corresponding leaves. The most damaged areas are those in the direct vicinity of the coal power plants, and the rate of damage caused in the environment is affected by the main wind direction. All sampling sites in Ptolemais basin are generally more or less polluted when compared with the control site.

  20. Limit theorems for sequences of random trees

    OpenAIRE

    Balding, David; Ferrari, Pablo A.; Fraiman, Ricardo; Sued, Mariela

    2004-01-01

    We consider a random tree and introduce a metric in the space of trees to define the ``mean tree'' as the tree minimizing the average distance to the random tree. When the resulting metric space is compact we have laws of large numbers and central limit theorems for sequence of independent identically distributed random trees. As application we propose tests to check if two samples of random trees have the same law.

  1. The Steiner tree problem

    CERN Document Server

    Hwang, FK; Winter, P

    1992-01-01

    The Steiner problem asks for a shortest network which spans a given set of points. Minimum spanning networks have been well-studied when all connections are required to be between the given points. The novelty of the Steiner tree problem is that new auxiliary points can be introduced between the original points so that a spanning network of all the points will be shorter than otherwise possible. These new points are called Steiner points - locating them has proved problematic and research has diverged along many different avenues. This volume is devoted to the assimilation of the rich field of intriguing analyses and the consolidation of the fragments. A section has been given to each of the three major areas of interest which have emerged. The first concerns the Euclidean Steiner Problem, historically the original Steiner tree problem proposed by Jarník and Kössler in 1934. The second deals with the Steiner Problem in Networks, which was propounded independently by Hakimi and Levin and has enjoyed the most...

  2. Distributed Merge Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther

    2013-01-08

    Improved simulations and sensors are producing datasets whose increasing complexity exhausts our ability to visualize and comprehend them directly. To cope with this problem, we can detect and extract significant features in the data and use them as the basis for subsequent analysis. Topological methods are valuable in this context because they provide robust and general feature definitions. As the growth of serial computational power has stalled, data analysis is becoming increasingly dependent on massively parallel machines. To satisfy the computational demand created by complex datasets, algorithms need to effectively utilize these computer architectures. The main strength of topological methods, their emphasis on global information, turns into an obstacle during parallelization. We present two approaches to alleviate this problem. We develop a distributed representation of the merge tree that avoids computing the global tree on a single processor and lets us parallelize subsequent queries. To account for the increasing number of cores per processor, we develop a new data structure that lets us take advantage of multiple shared-memory cores to parallelize the work on a single node. Finally, we present experiments that illustrate the strengths of our approach as well as help identify future challenges.

  3. Optical Inspection and Morphological Analysis of Diospyros kaki Plant Leaves for the Detection of Circular Leaf Spot Disease.

    Science.gov (United States)

    Wijesinghe, Ruchire Eranga; Lee, Seung-Yeol; Kim, Pilun; Jung, Hee-Young; Jeon, Mansik; Kim, Jeehyun

    2016-08-12

    The feasibility of using the bio-photonic imaging technique to assess symptoms of circular leaf spot (CLS) disease in Diospyros kaki (persimmon) leaf samples was investigated. Leaf samples were selected from persimmon plantations and were categorized into three groups: healthy leaf samples, infected leaf samples, and healthy-looking leaf samples from infected trees. Visually non-identifiable reduction of the palisade parenchyma cell layer thickness is the main initial symptom, which occurs at the initial stage of the disease. Therefore, we established a non-destructive bio-photonic inspection method using a 1310 nm swept source optical coherence tomography (SS-OCT) system. These results confirm that this method is able to identify morphological differences between healthy leaves from infected trees and leaves from healthy and infected trees. In addition, this method has the potential to generate significant cost savings and good control of CLS disease in persimmon fields.

  4. Optical Inspection and Morphological Analysis of Diospyros kaki Plant Leaves for the Detection of Circular Leaf Spot Disease

    Directory of Open Access Journals (Sweden)

    Ruchire Eranga Wijesinghe

    2016-08-01

    Full Text Available The feasibility of using the bio-photonic imaging technique to assess symptoms of circular leaf spot (CLS disease in Diospyros kaki (persimmon leaf samples was investigated. Leaf samples were selected from persimmon plantations and were categorized into three groups: healthy leaf samples, infected leaf samples, and healthy-looking leaf samples from infected trees. Visually non-identifiable reduction of the palisade parenchyma cell layer thickness is the main initial symptom, which occurs at the initial stage of the disease. Therefore, we established a non-destructive bio-photonic inspection method using a 1310 nm swept source optical coherence tomography (SS-OCT system. These results confirm that this method is able to identify morphological differences between healthy leaves from infected trees and leaves from healthy and infected trees. In addition, this method has the potential to generate significant cost savings and good control of CLS disease in persimmon fields.

  5. Human decision error (HUMDEE) trees

    Energy Technology Data Exchange (ETDEWEB)

    Ostrom, L.T.

    1993-08-01

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision.

  6. Tree felling: a necessary evil

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    CERN started a campaign of tree felling in 2010 for safety reasons, and it will continue this year in various parts of the Meyrin site. As in previous years, the trees cut down in 2013 will be recycled and some will be replaced.   Diseased tree that had to be cut down on the Meyrin site. In association with the Geneva nature and countryside directorate (Direction générale de la nature et du paysage, DGNP), CERN commissioned the Geneva school of landscaping, engineering and architecture (Haute école du paysage, d’ingénierie et d’architecture, HEPIA) to compile an inventory of the trees on the Meyrin site. In total, 1285 trees (excluding poplars) were recorded. 75.5% of these trees were declared to be in a good state of health (i.e. 971 trees), 21.5% in a moderate state of health (276 trees) and 3% in a poor state of health (38 trees). As for the poplars, the 236 specimens recorded on the Meyrin site were judged to be too old, to...

  7. Transmission and Propagation of 'Candidatus Liberibacter asiaticus' by Grafting with Individual Citrus Leaves.

    Science.gov (United States)

    Hilf, Mark E; Lewis, Reid S

    2016-05-01

    Huanglongbing (HLB) is a chronic, progressive decline disease in citrus associated with a systemic infection by the bacterium 'Candidatus Liberibacter asiaticus'. Transmission of the bacterium in the field is by the Asian citrus psyllid, Diaphorina citri Kuwayama. Experimental propagation of 'Ca. L. asiaticus' is done primarily by grafting pieces of bud wood from an infected plant. To produce a small-scale model system for investigation of pathogen biology, we investigated grafting single leaves from infected citrus plants as sources of inoculum for propagation of the bacterium. In total, 162 plants ranging in age from 3 to 18 months were grafted. Grafting with intact asymptomatic and HLB-symptomatic leaves resulted in 61 of 78 (78%) and 35 of 41 (85%) of the plants infected with 'Ca. L. asiaticus', respectively. Inoculum consisting of the leaf petiole only or only an inoculum tissue remnant under the bark of the receptor tree resulted in 6 of 12 (50%) and 7 of 31 (23%) infected trees, respectively. Real-time polymerase chain reaction (qPCR) assays verified the infection in plants, a majority of which developed the foliar blotchy mottle symptom considered diagnostic for HLB, while some plants also displayed the stunted, chlorotic shoots for which the disease is named. The qPCR data together with the symptoms displayed demonstrated that individual leaves from infected trees can serve as effective inoculum sources for transmission and propagation of 'Ca. L. asiaticus' via grafting.

  8. Transmission and Propagation of 'Candidatus Liberibacter asiaticus' by Grafting with Individual Citrus Leaves.

    Science.gov (United States)

    Hilf, Mark E; Lewis, Reid S

    2016-05-01

    Huanglongbing (HLB) is a chronic, progressive decline disease in citrus associated with a systemic infection by the bacterium 'Candidatus Liberibacter asiaticus'. Transmission of the bacterium in the field is by the Asian citrus psyllid, Diaphorina citri Kuwayama. Experimental propagation of 'Ca. L. asiaticus' is done primarily by grafting pieces of bud wood from an infected plant. To produce a small-scale model system for investigation of pathogen biology, we investigated grafting single leaves from infected citrus plants as sources of inoculum for propagation of the bacterium. In total, 162 plants ranging in age from 3 to 18 months were grafted. Grafting with intact asymptomatic and HLB-symptomatic leaves resulted in 61 of 78 (78%) and 35 of 41 (85%) of the plants infected with 'Ca. L. asiaticus', respectively. Inoculum consisting of the leaf petiole only or only an inoculum tissue remnant under the bark of the receptor tree resulted in 6 of 12 (50%) and 7 of 31 (23%) infected trees, respectively. Real-time polymerase chain reaction (qPCR) assays verified the infection in plants, a majority of which developed the foliar blotchy mottle symptom considered diagnostic for HLB, while some plants also displayed the stunted, chlorotic shoots for which the disease is named. The qPCR data together with the symptoms displayed demonstrated that individual leaves from infected trees can serve as effective inoculum sources for transmission and propagation of 'Ca. L. asiaticus' via grafting. PMID:26807818

  9. NMR-Based Metabolomic Analysis of Huanglongbing-Asymptomatic and -Symptomatic Citrus Trees.

    Science.gov (United States)

    Freitas, Deisy dos Santos; Carlos, Eduardo Fermino; Gil, Márcia Cristina Soares de Souza; Vieira, Luiz Gonzaga Esteves; Alcantara, Glaucia Braz

    2015-09-01

    Huanglongbing (HLB) is one of the most severe diseases that affects citrus trees worldwide and is associated with the yet uncultured bacteria Candidatus Liberibacter spp. To assess the metabolomic differences between HLB-asymptomatic and -symptomatic tissues, extracts from leaf and root samples taken from a uniform 6-year-old commercial orchard of Valencia trees were subjected to nuclear magnetic resonance (NMR) and chemometrics. The results show that the symptomatic trees had higher sucrose content in their leaves and no variation in their roots. In addition, proline betaine and malate were detected in smaller amounts in the HLB-affected symptomatic leaves. The changes in metabolic processes of the plant in response to HLB are corroborated by the relationship between the bacterial levels and the metabolic profiles.

  10. Analyzing lead absorption by the sycamore tree species in the industrial park of Rasht, Iran.

    Science.gov (United States)

    Hashemi, Seyed Armin; FallahChay, Mir Mozaffar; Tarighi, Fattaneh

    2015-07-01

    In this study, the subject of heavy metal concentration in soil, rock, sediment, surface water and groundwater, which can be caused by natural or man-posed pollution, was analyzed in the industrial park of Rasht. These concentrations were compared with the standard range of environmental data. Heavy metals are important environmental pollutants that can cause health hazards to humans, plants and microorganisms by entering food chain. This study aimed to investigate the absorption of lead by the leaves of sycamore tree species in the industrial park of Rasht. For this purpose, a sample of 32 sycamore tree species were randomly selected at a specified time, and the concentration of lead were measured using an atomic absorption device. Results showed that the amount of lead absorption by sycamore leaves is remarkable. The highest amount of lead absorption by sycamore leaves was detected at station 1 (Khazar Steel) and the lowest amount at station 2 (control station).

  11. [Diagnosing Low Health and Wood Borer Attacked Trees of Chinese Arborvitae by Using Thermography].

    Science.gov (United States)

    Wang, Fei; Wu, De-jun; Zhai, Guo-feng; Zang, Li-peng

    2015-12-01

    Water and energy metabolism of plants is very important actions in their lives. Although the studies about these actions by using thermography were often reported, seldom were found in detecting the health status of forest trees. In this study, we increase the measurement accuracy and comparability of thermo-images by creating the difference indices. Based on it, we exam the water and energy status in stem of Chinese arborvitae (Platycladus orientalis (L.) Franco) by detecting the variance of far infrared spectrum between sap-wood and heart-wood of the cross-section of felling trees and the cores from an increment borer using thermography. The results indicate that the sap rate between sapwood and heartwood is different as the variance of the vigor of forest trees. Meanwhile, the image temperature of scale leaves from Chinese arborvitae trees with different vigor is also dissimilar. The far infrared spectrum more responds the sap status not the wood percentage in comparing to the area rate between sapwood and heartwood. The image temperature rate can be used in early determining the health status of Chinese arborvitae trees. The wood borers such as Phloeosinus aubei Perris and Semanotus bifasciatus Motschulsky are the pests which usually attack the low health trees, dying trees, wilted trees, felled trees and new cultivated trees. This measuring technique may be an important index to diagnose the health and vigor status after a large number of measurements for Chinese arborvitae trees. Therefore, there is potential to be an important index to check the tree vigor and pest damage status by using this technique. It will be a key in the tending and management of ecological and public Chinese arborvitae forest.

  12. Estimating Single Tree Stem Volume of Pinus sylvestris Using Airborne Laser Scanner and Multispectral Line Scanner Data

    Directory of Open Access Journals (Sweden)

    Barbara Koch

    2011-05-01

    Full Text Available So far, only a few studies have been carried out in central European forests to estimate individual tree stem volume of pine trees from high resolution remote sensing data. In this article information derived from airborne laser scanner and multispectral line scanner data were tested to predict the stem volume of 178 pines (Pinus sylvestris in a study site in the south-west of Germany. First, tree crowns were automatically delineated using both multispectral and laser scanner data. Next, tree height, crown diameter and crown volume were derived for each crown segment. All combinations of the derived tree features were used as explanatory variables in allometric models to predict the stem volume. A model with tree height and crown diameter had the best performance with respect to the prediction accuracy determined by a leave-one-out cross-validation: Root Mean Square Error (RMSE = 24.02% and Bias = 1.36%.

  13. DIF Trees: Using Classification Trees to Detect Differential Item Functioning

    Science.gov (United States)

    Vaughn, Brandon K.; Wang, Qiu

    2010-01-01

    A nonparametric tree classification procedure is used to detect differential item functioning for items that are dichotomously scored. Classification trees are shown to be an alternative procedure to detect differential item functioning other than the use of traditional Mantel-Haenszel and logistic regression analysis. A nonparametric…

  14. Sussing Merger Trees: A proposed Merger Tree data format

    CERN Document Server

    Thomas, Peter A; Tweed, Dylan; Benson, Andrew J; Croton, Darren; Elahi, Pascal; Henriques, Bruno; Iliev, Ilian T; Knebe, Alexander; Lux, Hanni; Mao, Yao-Yuan; Neyrinck, Mark; Pearce, Frazer R; Rodriguez-Gomez, Vicente; Schneider, Aurel; Srisawat, Chaichalit

    2015-01-01

    We propose a common terminology for use in describing both temporal merger trees and spatial structure trees for dark-matter halos. We specify a unified data format in HDF5 and provide example I/O routines in C, FORTRAN and PYTHON.

  15. Tree Decomposition based Steiner Tree Computation over Large Graphs

    OpenAIRE

    Wei-Kleiner, Fang

    2013-01-01

    In this paper, we present an exact algorithm for the Steiner tree problem. The algorithm is based on certain pre-computed index structures. Our algorithm offers a practical solution for the Steiner tree problems on graphs of large size and bounded number of terminals.

  16. [Magnetic Response of Dust-loaded Leaves in Parks of Shanghai to Atmospheric Heavy Metal Pollution].

    Science.gov (United States)

    Liu, Fei; Chu, Hui-min; Zheng, Xiang-min

    2015-12-01

    To reveal the magnetic response to the atmospheric heavy metal pollution in leaves along urban parks, Camphor leaf samples, widely distributed at urban parks, were collected along the year leading wind direction of Shanghai, by setting two vertical and horizontal sections, using rock magnetic properties and heavy metal contents analysis. The results showed that the magnetic minerals of samples were predominated by ferromagnetic minerals, and both the concentration and grain size of magnetite particles gradually decreased with the winter monsoon direction from the main industrial district. A rigorous cleaning of leaves using ultrasonic agitator washer could remove about 63%-90% of low-field susceptibility values of the leaves, and this strongly indicated that the intensity of magnetic signal was mainly controlled by the PMs accumulated on the leaves surfaces. Moreover, there was a significant linear relationship between heavy metals contents (Fe, Mn, Zn, Cu, Cr, V and Pb) and magnetic parameters (0.442 ≤ R ≤ 0.799, P magnetic parameters of urban park leaves could be used as a proxy for atmospheric heavy metal pollution. The results of multivariate statistical analysis showed that the content of magnetic minerals and heavy metal indust-loaded tree leaves was affected by associated pollution of industry and traffic.

  17. Transfer characterization of sulfur from coal-burning emission to plant leaves by PIXE and XANES

    Energy Technology Data Exchange (ETDEWEB)

    Bao, L.M.; Zhang, G.L.; Zhang, Y.X.; Li, Y.; Lin, J.; Liu, W.; Cao, Q.C.; Zhao, Y.D.; Ma, C.Y.; Han, Y. [Chinese Academy of Sciences, Shanghai (China). Shanghai Institute of Applied Physics

    2009-11-15

    The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO{sub 4}2{sup -}. It can monitor the sulfur pollution in atmosphere.

  18. [Magnetic Response of Dust-loaded Leaves in Parks of Shanghai to Atmospheric Heavy Metal Pollution].

    Science.gov (United States)

    Liu, Fei; Chu, Hui-min; Zheng, Xiang-min

    2015-12-01

    To reveal the magnetic response to the atmospheric heavy metal pollution in leaves along urban parks, Camphor leaf samples, widely distributed at urban parks, were collected along the year leading wind direction of Shanghai, by setting two vertical and horizontal sections, using rock magnetic properties and heavy metal contents analysis. The results showed that the magnetic minerals of samples were predominated by ferromagnetic minerals, and both the concentration and grain size of magnetite particles gradually decreased with the winter monsoon direction from the main industrial district. A rigorous cleaning of leaves using ultrasonic agitator washer could remove about 63%-90% of low-field susceptibility values of the leaves, and this strongly indicated that the intensity of magnetic signal was mainly controlled by the PMs accumulated on the leaves surfaces. Moreover, there was a significant linear relationship between heavy metals contents (Fe, Mn, Zn, Cu, Cr, V and Pb) and magnetic parameters (0.442 ≤ R ≤ 0.799, P < 0.05), which suggested that magnetic parameters of urban park leaves could be used as a proxy for atmospheric heavy metal pollution. The results of multivariate statistical analysis showed that the content of magnetic minerals and heavy metal indust-loaded tree leaves was affected by associated pollution of industry and traffic. PMID:27011970

  19. Chemical composition and phytotoxicity of volatile essential oil from intact and fallen leaves of Eucalyptus citriodora.

    Science.gov (United States)

    Batish, Daizy R; Singh, Harminder P; Setia, Nidhi; Kaur, Shalinder; Kohli, Ravinder K

    2006-01-01

    A total of 23 volatile constituents was identified and characterized by GC and GC-MS in the volatile essential oil extracted from intact (juvenile and adult) and fallen (senescent and leaf litter) leaves of lemon-scented eucalyptus (Eucalyptus citriodora Hook.). The leaves differed in their pigment, water and protein content, and C/N ratio. The oils were, in general, monoterpenoid in nature with 18 monoterpenes and 5 sesquiterpenes. However, a great variability in the amount of essential oils and their individual constituents was observed in different leaf tissues. The amount was maximum in the senescent leaves collected from the floor of the tree closely followed by that from juvenile leaves. In all, 19 constituents were identified in oil from juvenile and senescent leaves compared to 23 in adult leaves and 20 in leaf litter, respectively. Citronellal, a characteristic monoterpene of the oil reported hitherto was found to be more (77-78%) in the juvenile and senescent leaves compared to 48 and 54%, respectively, in the adult leaves and leaf litter. In the adult leaves, however, the content of citronellol--another important monoterpene-- was very high (21.9%) compared to other leaf types (7.8-12.2%). Essential oil and its two major monoterpenes viz. citronellal and citronellol were tested for their phytotoxicity against two weeds (Amaranthus viridis and Echinochloa crus-galli) and two crops (Triticum aestivum and Oryza sativa) under laboratory conditions. A difference in the phytotoxicity, measured in terms of seedling length and dry weight, of oil from different leaves and major monoterpenes was observed. Oil from adult leaves was found to be most phytotoxic although it occurs in smaller amount (on unit weight basis). The different toxicity of different oil types was due to the relative amount of individual monoterpenes present in the oil, their solubility and interactive action. The study concludes that oil from senescent and juvenile leaves being rich in

  20. RECRUITMENT FINANCED BY SAVED LEAVE (RSL PROGRAMME)

    CERN Document Server

    Division du Personnel; Tel. 73903

    1999-01-01

    Transfer to the saved leave account and saved leave bonusStaff members participating in the RSL programme may opt to transfer up to 10 days of unused annual leave or unused compensatory leave into their saved leave account, at the end of the leave year, i.e. 30 September (as set out in the implementation procedure dated 27 August 1997).A leave transfer request form, which you should complete, sign and return, if you wish to use this possibility, has been addressed you. To allow the necessary time for the processing of your request, you should return it without delay.As foreseen in the implementation procedure, an additional day of saved leave will be granted for each full period of 20 days remaining in the saved leave account on 31 December 1999, for any staff member participating in the RSL programme until that date.For part-time staff members participating in the RSL programme, the above-mentioned days of leave (annual, compensatory and saved) are adjusted proportionally to their contractual working week as...

  1. The green leaves of Nanjing

    Institute of Scientific and Technical Information of China (English)

    Rainer Thomm

    2004-01-01

    <正> August 1989Hot town, summer in the city, with temperatures in the high 30s. Amazingly enough, the heat is bearable because there is plenty of shade. Nanjing is famous for the plane trees that line its streets and avenues. It’s a good thing for people like me who have little vegetation on their heads: we don’t have to worry about getting sunburnt on top.1989 being a year when nothing much is being done by way of business, I have plenty of time to travel around different parts of China. Nanjing most certainly is one of the nicer destinations among the places I am visiting. One of the most beautiful features of the city is the Zijin Shan (Purple Mountain) right in the middle of it. Few places I have been to can boast of such an attraction. Miles and miles of woodland to climb, and then

  2. Tree Diametric Increment and Litterfall Production in an Eastern Amazonian Forest: the Role of Functional Groups

    Science.gov (United States)

    Camargo, P. B. D.; Ferreira, M. L.; Oliveira Junior, R. C.; Saleska, S. R.

    2014-12-01

    Tree growth is a biotic variable of great importance in understanding the dynamics of tree communities and may be used as a tool in studies of biological or climate modeling. Some climate models predict more recurrent climate anomalies in this century, which may alter the functioning of tropical forests with serious structural and demographic implications. The present study aimed to evaluate the profile of tree growth and litterfall production in an eastern Amazon forest, which has suffered recent climatic disturbances. We contrasted different functional groups based on wood density (stem with 0.55; 0.56-0.7; >0.7 g cm-3), light availability (crown illumination index; high illuminated crown - IIC1 until shaded crown - IIC5), and, size class (trees 10-22.5; 22.6-35; 35.1-55; 55,1-90; >90 cm dbh). Tree diameter increment was monthly measured from November 2011 to September 2013 by using dendrometer bands installed on 850 individuals from different families. Litterfall was collected in 64 circular traps, oven dried and weighed, separated into leaves, twigs, reproductive parts and miscellaneous. During the rainy season the sampled trees had the highest rates of tree diametric increment. When analyzing the data by functional groups, large trees had faster growth, but when grouped by wood density, trees with wood density up to 0.55 and between 0.56 and 0.7 g cm-3 had the fastest rates of growth. When grouped by crown illumination index, trees exposed to higher levels of light grew more in comparison to partially shaded trees. Maximum daily air temperature and precipitation were the most important environmental variables in determining the diametric increment profile of the trees. Litterfall production was estimated to be 7.1 Mg ha-1.year-1 and showed a strong seasonal pattern, with dry season production being higher than in the rainy season. Leaves formed the largest fraction of the litterfall, followed by twigs, reproductive parts, and finally miscellaneous. These

  3. Concentration change of radiocaesium in persimmon leaves and fruits. Observation results in 2011 Spring - 2013 Summer

    International Nuclear Information System (INIS)

    To make dried-fruits of persimmon (Diospyros kaki), its fresh fruits were generally processed to decrease their water-contents to about 30-50%. During this food process, their radiocaesium concentrations increased without any loss, and, occasionally, the dried-fruits may exceed the food standard level of 100 Bq/kg (edible form). Thus, it is necessary to estimate the radiocaesium concentrations in the products before the fresh fruit harvesting and processing. For this purpose, radiocaesium concentrations in leaves of persimmon trees were monitored with time. The 137Cs concentrations in the fruits were usually lower than those in the leaves and the concentration ratio was less than 0.4 on a fresh weight basis. The ratio became smaller when closer the harvest season. Thus the concentration of leaves could be a good indicator to estimate the processed persimmon fruits. (author)

  4. Impacts of age-dependent tree sensitivity and dating approaches on dendrogeomorphic time series of landslides

    Science.gov (United States)

    Šilhán, Karel; Stoffel, Markus

    2015-05-01

    Different approaches and thresholds have been utilized in the past to date landslides with growth ring series of disturbed trees. Past work was mostly based on conifer species because of their well-defined ring boundaries and the easy identification of compression wood after stem tilting. More recently, work has been expanded to include broad-leaved trees, which are thought to produce less and less evident reactions after landsliding. This contribution reviews recent progress made in dendrogeomorphic landslide analysis and introduces a new approach in which landslides are dated via ring eccentricity formed after tilting. We compare results of this new and the more conventional approaches. In addition, the paper also addresses tree sensitivity to landslide disturbance as a function of tree age and trunk diameter using 119 common beech (Fagus sylvatica L.) and 39 Crimean pine (Pinus nigra ssp. pallasiana) trees growing on two landslide bodies. The landslide events reconstructed with the classical approach (reaction wood) also appear as events in the eccentricity analysis, but the inclusion of eccentricity clearly allowed for more (162%) landslides to be detected in the tree-ring series. With respect to tree sensitivity, conifers and broad-leaved trees show the strongest reactions to landslides at ages comprised between 40 and 60 years, with a second phase of increased sensitivity in P. nigra at ages of ca. 120-130 years. These phases of highest sensitivities correspond with trunk diameters at breast height of 6-8 and 18-22 cm, respectively (P. nigra). This study thus calls for the inclusion of eccentricity analyses in future landslide reconstructions as well as for the selection of trees belonging to different age and diameter classes to allow for a well-balanced and more complete reconstruction of past events.

  5. Role of leaves in phototropism.

    Science.gov (United States)

    Lam, S L; Leopold, A C

    1966-05-01

    Experiments with green seedlings of sunflower (Helianthus annuns L.) indicate the existence of a phototropic mechanism which involves the leaves or cotyledons, and which can produce an asymmetry of auxin content without the involvement of lateral auxin transport, the classic explanation of phototropism in etiolated seedlings. The basic lines of evidence for the leaf-mediated tropism are: 1) darkening of one cotyledon will cause curvature of the stem toward the lighted cotyledon: 2) the darkened cotyledon sustains an enhanced growth rate in the stem below it: 3) conversely, light suppresses the growth-stimulating effects of a single cotyledon: and 4) more diffusible auxin is obtained from the stem below darkened cotyledons than below lighted ones.

  6. Wading bird guano contributes to Hg accumulation in tree island soils in the Florida Everglades

    International Nuclear Information System (INIS)

    Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those in mid and tail region, and marsh soils. Hg concentrations in bird guano (286 μg kg−1) were significantly higher than those in mammal droppings (105 μg kg−1) and plant leaves (53 μg kg−1). In addition, Hg concentrations and δ15N values displayed positive correlation in soils influenced by guano. During 1998–2010, estimated annual Hg deposition by guano was 148 μg m−2 yr−1 and ∼8 times the atmospheric deposition. Highlights: • Hg concentrations in the head region of tree islands were the highest. • Hg concentrations in bird guano (286 μg kg−1) were significantly higher than those in mammal droppings and plant leaves. • Hg concentrations and δ15N values showed positive correlation in soils influenced by guano. • Estimated annual Hg deposition by guano was 148 μg m−2 yr−1, ∼8 times the atmospheric deposition. -- The annual Hg deposition by bird guano to tree island soils in the Everglades was ∼8 times the atmospheric deposition

  7. On aligning trees

    CERN Document Server

    Calder, J

    1997-01-01

    The increasing availability of corpora annotated for linguistic structure prompts the question: if we have the same texts, annotated for phrase structure under two different schemes, to what extent do the annotations agree on structuring within the text? We suggest the term tree alignment to indicate the situation where two markup schemes choose to bracket off the same text elements. We propose a general method for determining agreement between two analyses. We then describe an efficient implementation, which is also modular in that the core of the implementation can be reused regardless of the format of markup used in the corpora. The output of the implementation on the Susanne and Penn treebank corpora is discussed.

  8. Tree Quantum Field Theory

    CERN Document Server

    Gurau, R; Rivasseau, V

    2008-01-01

    We propose a new formalism for quantum field theory which is neither based on functional integrals, nor on Feynman graphs, but on marked trees. This formalism is constructive, i.e. it computes correlation functions through convergent rather than divergent expansions. It applies both to Fermionic and Bosonic theories. It is compatible with the renormalization group, and it allows to define non-perturbatively {\\it differential} renormalization group equations. It accommodates any general stable polynomial Lagrangian. It can equally well treat noncommutative models or matrix models such as the Grosse-Wulkenhaar model. Perhaps most importantly it removes the space-time background from its central place in QFT, paving the way for a nonperturbative definition of field theory in noninteger dimension.

  9. Fires on trees

    CERN Document Server

    Bertoin, Jean

    2010-01-01

    We consider random dynamics on the edges of a uniform Cayley tree with $n$ vertices, in which edges are either inflammable, fireproof, or burt. Every inflammable edge is replaced by a fireproof edge at unit rate, while fires start at smaller rate $n^{-\\alpha}$ on each inflammable edge, then propagate through the neighboring inflammable edges and are only stopped at fireproof edges. A vertex is called fireproof when all its adjacent edges are fireproof. We show that as $n\\to \\infty$, the density of fireproof vertices converges to 1 when $\\alpha>1/2$, to 0 when $\\alpha<1/2$, and to some non-degenerate random variable when $\\alpha=1/2$. We further study the connectivity of the fireproof forest, in particular the existence of a giant component.

  10. Random Projection Trees Revisited

    CERN Document Server

    Dhesi, Aman

    2010-01-01

    The Random Projection Tree structures proposed in [Freund-Dasgupta STOC08] are space partitioning data structures that automatically adapt to various notions of intrinsic dimensionality of data. We prove new results for both the RPTreeMax and the RPTreeMean data structures. Our result for RPTreeMax gives a near-optimal bound on the number of levels required by this data structure to reduce the size of its cells by a factor $s \\geq 2$. We also prove a packing lemma for this data structure. Our final result shows that low-dimensional manifolds have bounded Local Covariance Dimension. As a consequence we show that RPTreeMean adapts to manifold dimension as well.

  11. Estimating Leaf Water Potential of Giant Sequoia Trees from Airborne Hyperspectral Imagery

    Science.gov (United States)

    Francis, E. J.; Asner, G. P.

    2015-12-01

    Recent drought-induced forest dieback events have motivated research on the mechanisms of tree survival and mortality during drought. Leaf water potential, a measure of the force exerted by the evaporation of water from the leaf surface, is an indicator of plant water stress and can help predict tree mortality in response to drought. Scientists have traditionally measured water potentials on a tree-by-tree basis, but have not been able to produce maps of tree water potential at the scale of a whole forest, leaving forest managers unaware of forest drought stress patterns and their ecosystem-level consequences. Imaging spectroscopy, a technique for remote measurement of chemical properties, has been used to successfully estimate leaf water potentials in wheat and maize crops and pinyon-pine and juniper trees, but these estimates have never been scaled to the canopy level. We used hyperspectral reflectance data collected by the Carnegie Airborne Observatory (CAO) to map leaf water potentials of giant sequoia trees (Sequoiadendron giganteum) in an 800-hectare grove in Sequoia National Park. During the current severe drought in California, we measured predawn and midday leaf water potentials of 48 giant sequoia trees, using the pressure bomb method on treetop foliage samples collected with tree-climbing techniques. The CAO collected hyperspectral reflectance data at 1-meter resolution from the same grove within 1-2 weeks of the tree-level measurements. A partial least squares regression was used to correlate reflectance data extracted from the 48 focal trees with their water potentials, producing a model that predicts water potential of giant sequoia trees. Results show that giant sequoia trees can be mapped in the imagery with a classification accuracy of 0.94, and we predicted the water potential of the mapped trees to assess 1) similarities and differences between a leaf water potential map and a canopy water content map produced from airborne hyperspectral data, 2

  12. TREE DECOMPOSITIONS OF MULTIGRAPHS

    Institute of Scientific and Technical Information of China (English)

    SHI Minyong

    1999-01-01

    For a graph G, ifE(G) can be partitioned into several pairwise disjointsets as { E1, E2,……,El} such thatthe subgraph induced by Ei is a tree of orderki, (i=1,2, ……, l), then G is said to have a {k1,k2,……, kl}-tree-decomposition, denoted by {k1,k2,……, kl}∈G.For k≥1 and l≥0, a collection(G)(k,l) is the setof multigraphs such that G∈(G)(k,l) if and only if ε(G) = k(|G|-1)-l and ε(H)≤max{(k-1)(|H|-1), k(|H|-1)-l} for any subgraph H of G.We prove that (1) If k≥2, 0≤l≤3 and G∈(G)(k,l) of order n≥l+1, then {n,n,……, n-l}∈ G. (2) If k≥2 and G∈(G)(k,2) oforder n≥3, then {n,n,……, n,n-2}∈G and {n,n,……, n,n-1,n-1}∈G. (3) If k3 and G∈(G)(k,3) oforder n≥4, then {n,n,……, n,n-3}∈G ,{ n,n,……, n,n-1,n-2}∈ G and {n,n, ……, n,n-1,n-1,n-1}∈G.

  13. Tree Hydraulics: How Sap Rises

    Science.gov (United States)

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

  14. Some Hopf algebras of trees

    NARCIS (Netherlands)

    Laan, P. van der

    2001-01-01

    In the literature several Hopf algebras that can be described in terms of trees have been studied. This paper tries to answer the question whether one can understand some of these Hopf algebras in terms of a single mathematical construction. The starting point is the Hopf algebra of rooted trees as

  15. Community tree nursery, Meru, Kenya.

    OpenAIRE

    2006-01-01

    This is a photograph of a community tree nursery, Meru, Kenya. In this nursery a community group has started a nursery to provide seedlings for their own forest reforestation projects as well as for sale. This shows that use of common pool resources and shows community forestry activities that also do private tree planting on homesteads.

  16. The supernatural characters and powers of sacred trees in the Holy Land

    Science.gov (United States)

    Dafni, Amots

    2007-01-01

    This article surveys the beliefs concerning the supernatural characteristics and powers of sacred trees in Israel; it is based on a field study as well as a survey of the literature and includes 118 interviews with Muslims and Druze. Both the Muslims and Druze in this study attribute supernatural dimensions to sacred trees which are directly related to ancient, deep-rooted pagan traditions. The Muslims attribute similar divine powers to sacred trees as they do to the graves of their saints; the graves and the trees are both considered to be the abode of the soul of a saint which is the source of their miraculous powers. Any violation of a sacred tree would be strictly punished while leaving the opportunity for atonement and forgiveness. The Druze, who believe in the transmigration of souls, have similar traditions concerning sacred trees but with a different religious background. In polytheistic religions the sacred grove/forest is a centre of the community's official worship; any violation of the trees is regarded as a threat to the well being of the community. Punishments may thus be collective. In the monotheistic world (including Christianity, Islam and Druze) the pagan worship of trees was converted into the worship/adoration of saints/prophets; it is not a part of the official religion but rather a personal act and the punishments are exerted only on the violating individual. PMID:17319970

  17. Incorporating social and cultural significance of large old trees in conservation policy.

    Science.gov (United States)

    Blicharska, Malgorzata; Mikusiński, Grzegorz

    2014-12-01

    In addition to providing key ecological functions, large old trees are a part of a social realm and as such provide numerous social-cultural benefits to people. However, their social and cultural values are often neglected when designing conservation policies and management guidelines. We believe that awareness of large old trees as a part of human identity and cultural heritage is essential when addressing the issue of their decline worldwide. Large old trees provide humans with aesthetic, symbolic, religious, and historic values, as well as concrete tangible benefits, such as leaves, branches, or nuts. In many cultures particularly large trees are treated with reverence. Also, contemporary popular culture utilizes the image of trees as sentient beings and builds on the ancient myths that attribute great powers to large trees. Although the social and cultural role of large old trees is usually not taken into account in conservation, accounting for human-related values of these trees is an important part of conservation policy because it may strengthen conservation by highlighting the potential synergies in protecting ecological and social values.

  18. Modelling tree biomasses in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Repola, J.

    2013-06-01

    Biomass equations for above- and below-ground tree components of Scots pine (Pinus sylvestris L), Norway spruce (Picea abies [L.] Karst) and birch (Betula pendula Roth and Betula pubescens Ehrh.) were compiled using empirical material from a total of 102 stands. These stands (44 Scots pine, 34 Norway spruce and 24 birch stands) were located mainly on mineral soil sites representing a large part of Finland. The biomass models were based on data measured from 1648 sample trees, comprising 908 pine, 613 spruce and 127 birch trees. Biomass equations were derived for the total above-ground biomass and for the individual tree components: stem wood, stem bark, living and dead branches, needles, stump, and roots, as dependent variables. Three multivariate models with different numbers of independent variables for above-ground biomass and one for below-ground biomass were constructed. Variables that are normally measured in forest inventories were used as independent variables. The simplest model formulations, multivariate models (1) were mainly based on tree diameter and height as independent variables. In more elaborated multivariate models, (2) and (3), additional commonly measured tree variables such as age, crown length, bark thickness and radial growth rate were added. Tree biomass modelling includes consecutive phases, which cause unreliability in the prediction of biomass. First, biomasses of sample trees should be determined reliably to decrease the statistical errors caused by sub-sampling. In this study, methods to improve the accuracy of stem biomass estimates of the sample trees were developed. In addition, the reliability of the method applied to estimate sample-tree crown biomass was tested, and no systematic error was detected. Second, the whole information content of data should be utilized in order to achieve reliable parameter estimates and applicable and flexible model structure. In the modelling approach, the basic assumption was that the biomasses of

  19. Changes in free amino acids and polyamine levels in Satsuma leaves in response to Asian citrus psyllid infestation and water stress.

    Science.gov (United States)

    Malik, Nasir S A; Perez, Jose L; Kunta, Madhurababu; Patt, Joseph M; Mangan, Robert L

    2014-12-01

    The effects of biotic and abiotic stresses on changes in amino acids and polyamine levels in Satsuma orange (Citrus unshiu; cultivar Owari) leaves were investigated. Asian citrus psyllids Diaphorina citri (Kuwayama) (ACP) infestation was used to induce biotic stress while a water deficit was imposed to induce abiotic stress. Potted trees were infested by placing 50 psyllids on 3 citrus leaves enclosed in nylon mesh bags for 5 d. A parallel set of plants were kept water stressed by maintaining the soil at 20% water holding capacity for 5 d. Levels of total free amino acids were higher in water stressed and ACP infested leaves. Polyamine putrescine increased in infested leaves but not in water stressed leaves. Proline was the most abundant amino acid and its levels significantly increased by both biotic and abiotic stresses. Proline levels in infested leaves were significantly higher than the water stressed leaves. Histidine, methionine, asparagine, arginine, serine, and leucine levels also increased significantly in infested leaves, but in water stressed leaves only leucine, methionine, and threonine increased. Levels of amino acids, such as tyrosine, isoleucine, phenylalanine, glutamic acid, and alanine, declined in infested leaves. Under water stress asparagine, phenylalanine, serine, and histidine also declined compared to controls. This indicates that while proteolysis occurred under both stresses, metabolic conversion of amino acids was different under the two stresses. In ACP infested leaves some amino acids may be used as feeding material and/or converted into secondary metabolites for defense. PMID:24178691

  20. The effect of treating plum tree with Rovral (iprodion and Euparen (dichlofluanid on the content of soluble solids in fruit

    Directory of Open Access Journals (Sweden)

    Halina Borecka

    2013-12-01

    Full Text Available The concentration of soluble solids in plum fruit varied and depended on the cultivar, year, and fungicide treatment. Plums from trees treated with Rovral (iprodion contained in some case the lowest level of soluble solids, higher or equal levels were found in those sprayed with Euparen (dichlofluanid, and the highest concentration of soluble solids was in fruits from untreated trees. Explanation of this phenomenon is possible by looking for changes in photosynthesis of treated and untreated leaves. Fungicide treatment of some plum cultivars, particularly with Rovral, decreased the photosynthesis of the leaves.

  1. Sweet potato leaves for growing pigs

    OpenAIRE

    An, Le

    2004-01-01

    The aim of the present studies was to evaluate the potential of using sweet potato leaves (Ipomoea batatas (L.) Lam) as a protein source in diets for growing pigs. A number of sweet potato varieties were evaluated with respect to the biomass yield of the leaves, stems and tubers under different leaf harvesting intervals and defoliation techniques with the aim of selecting the best varieties for forage production. The biomass yields of leaves, stems and tubers were found to vary according to v...

  2. Predicting tree crown defoliation using color-infrared orthophoto maps

    Directory of Open Access Journals (Sweden)

    Eigirdas M

    2013-01-01

    Full Text Available Orthophoto maps based on color-infrared aerial photography have been used by the Lithuanian forest inventory since 2001. This study aimed to investigate the opportunities for using these orthophoto maps to predict tree crown defoliation at the single tree and sample plot levels. The test area was located in the Aukstaitija National Park, eastern Lithuania, and it was photographed in the summer of 2008 using a Vexcel UltraCam D digital frame aerial camera to produce digital orthophoto maps with a 0.5 x 0.5 m ground sampling density. Some 1721 tree crowns (mainly pine, spruce and birch, located in 166 permanent sample plots, were identified and delineated on the orthophoto maps. Crown defoliation and other dendrometric characteristics were field-estimated for all of these trees in summer 2008. Judgments on the suitability of using color-infrared aerial photography based orthophotos to estimate tree crown defoliation were based on the accuracy of the defoliation prediction. Defoliation for each crown was predicted using the non-parametric k-Nearest Neighbor (k-NN method and characteristics extracted from the digital orthophoto maps as the auxiliary variables for prediction. Prediction accuracies were validated using the “Leave One Out” technique by comparing the predicted data with data from field-assessed crown defoliations. The lowest root mean square errors for the predicted tree crown defoliation values were 7.564 for pine trees, 9.166 for spruce and 7.712 for birch and the highest coefficients of correlation between field-estimated and predicted crown defoliations were 0.576, 0.600 and 0.386, respectively. However, there was no best performing solution for using the k-NN prediction found, as the best results were achieved using different approaches. Next, predicted and field estimated tree crown defoliation values were aggregated up to the sample plot level by taking an averaging of trees in the same sample plot. The root mean square error

  3. Translocation of radiocesium from stems and leaves of plants and the effect on radiocesium concentrations in newly emerged plant tissues

    International Nuclear Information System (INIS)

    An accident occurred at the Fukushima Dai-ichi Nuclear Power Plant in March 2011 at which time large amounts of radionuclides were released into the atmosphere and the sea. In early May 2011, it was found that newly emerged tea (Camellia sinensis) leaves contained radiocesium, both 134Cs and 137Cs in some areas more than 300 km away from the Fukushima plant. To understand the mechanisms of radiocesium transfer to newly emerged tissues (shoots, leaves and fruits) of other plants in the future, radiocesium concentrations in newly emerged leaves of 14 plant species collected from the sampling areas in and near National Institute of Radiological Sciences in Chiba, Japan. The studied plant types were: (1) herbaceous plants, (2) woody plants with no old leaves at the time of the March accident, and (3) woody plants with old leaves out before the accident. About 40–50 d after the start of the accident, newly emerged leaves from woody plant with old leaves tended to show higher values than other woody or herbaceous plants. Concentrations of radiocesium in newly emerged tissues of trees decreased with time, but they did not decrease to the level of herbaceous plants. The type of the plant and presence of old leaves at the time of the heavy deposition period affected the radiocesium concentrations in newly emerged tissues.

  4. Fingerprint Gender Classification using Univariate Decision Tree (J48

    Directory of Open Access Journals (Sweden)

    S. F. Abdullah

    2016-09-01

    Full Text Available Data mining is the process of analyzing data from a different category. This data provide information and data mining will extracts a new knowledge from it and a new useful information is created. Decision tree learning is a method commonly used in data mining. The decision tree is a model of decision that looklike as a tree-like graph with nodes, branches and leaves. Each internal node denotes a test on an attribute and each branch represents the outcome of the test. The leaf node which is the last node will holds a class label. Decision tree classifies the instance and helps in making a prediction of the data used. This study focused on a J48 algorithm for classifying a gender by using fingerprint features. There are four types of features in the fingerprint that is used in this study, which is Ridge Count (RC, Ridge Density (RD, Ridge Thickness to Valley Thickness Ratio (RTVTR and White Lines Count (WLC. Different cases have been determined to be executed with the J48 algorithm and a comparison of the knowledge gain from each test is shown. All the result of this experiment is running using Weka and the result achieve 96.28% for the classification rate.

  5. Recovery of trees from drought depends on belowground sink control.

    Science.gov (United States)

    Hagedorn, Frank; Joseph, Jobin; Peter, Martina; Luster, Jörg; Pritsch, Karin; Geppert, Uwe; Kerner, Rene; Molinier, Virginie; Egli, Simon; Schaub, Marcus; Liu, Jian-Feng; Li, Maihe; Sever, Krunoslav; Weiler, Markus; Siegwolf, Rolf T W; Gessler, Arthur; Arend, Matthias

    2016-01-01

    Climate projections predict higher precipitation variability with more frequent dry extremes(1). CO2 assimilation of forests decreases during drought, either by stomatal closure(2) or by direct environmental control of sink tissue activities(3). Ultimately, drought effects on forests depend on the ability of forests to recover, but the mechanisms controlling ecosystem resilience are uncertain(4). Here, we have investigated the effects of drought and drought release on the carbon balances in beech trees by combining CO2 flux measurements, metabolomics and (13)CO2 pulse labelling. During drought, net photosynthesis (AN), soil respiration (RS) and the allocation of recent assimilates below ground were reduced. Carbohydrates accumulated in metabolically resting roots but not in leaves, indicating sink control of the tree carbon balance. After drought release, RS recovered faster than AN and CO2 fluxes exceeded those in continuously watered trees for months. This stimulation was related to greater assimilate allocation to and metabolization in the rhizosphere. These findings show that trees prioritize the investment of assimilates below ground, probably to regain root functions after drought. We propose that root restoration plays a key role in ecosystem resilience to drought, in that the increased sink activity controls the recovery of carbon balances. PMID:27428669

  6. Spatial structuring of bacterial communities within individual Ginkgo biloba trees.

    Science.gov (United States)

    Leff, Jonathan W; Del Tredici, Peter; Friedman, William E; Fierer, Noah

    2015-07-01

    Plant-associated microorganisms affect the health of their hosts in diverse ways, yet the distribution of these organisms within individual plants remains poorly understood. To address this knowledge gap, we assessed the spatial variability in bacterial community diversity and composition found on and in aboveground tissues of individual Ginkgo biloba trees. We sampled bacterial communities from > 100 locations per tree, including leaf, branch and trunk samples and used high-throughput sequencing of the 16S rRNA gene to determine the diversity and composition of these communities. Bacterial community structure differed strongly between bark and leaf samples, with bark samples harbouring much greater bacterial diversity and a community composition distinct from leaves. Within sample types, we observed clear spatial patterns in bacterial diversity and community composition that corresponded to the samples' proximity to the exterior of the tree. The composition of the bacterial communities found on trees is highly variable, but this variability is predictable and dependent on sampling location. Moreover, this work highlights the importance of carefully considering plant spatial structure when characterizing the microbial communities associated with plants and their impacts on plant hosts.

  7. Random self-similar trees and a hierarchical branching process

    CERN Document Server

    Kovchegov, Yevgeniy

    2016-01-01

    We study self-similarity in random binary rooted trees. In a well-understood case of Galton-Watson trees, a distribution is called self-similar if it is invariant with respect to the operation of pruning, which cuts the tree leaves. This only happens in the critical case (a constant process progeny), which also exhibits other special symmetries. We extend the prune-invariance set-up to a non-Markov situation and trees with edge lengths. In this general case the class of self-similar processes becomes much richer and covers a variety of practically important situations. The main result is construction of the hierarchical branching processes that satisfy various self-similarity constraints (distributional, mean, in edge-lengths) depending on the process parameters. Taking the limit of averaged stochastic dynamics, as the number of trajectories increases, we obtain a deterministic system of differential equations that describes the process evolution. This system is used to establish a phase transition that separ...

  8. Ecophysiological studies on photosynthesis and pigment adaptation of light and shade leaves; Oekophysiologische Untersuchungen zur Photosynthese und Pigment-Adaptation bei Licht- und Schattenblaettern

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, M.

    2005-07-01

    Photosynthetic function and pigment adaptation, as well as several other leaf parameters of light and shade adapted leaves of trees were studied under different environmental conditions. These measurements were performed primarily on a solitary standing beech during a summer drought stress period and an autumnal partial regeneration of physiological activity. Mainly investigated were beech leaves, sun leaves growing at the south side of the tree and shade leaves from the interior of the crown, since beech leaves show the strongest physiological light and shade adaptation responses among all deciduous trees. Similar adaptation studies were also performed with red, light-exposed, anthocyanin-containing leaves of the herbaceous purple foliage plant Perilla (beefsteak plant, Chinese basil) and some other plant species with either slightly or more red leaves, in order to check whether the accumulation of anthocyanins in the upper leaf epidermis of sun exposed-leaves blocks the high-light induced formation of sun-type chloroplasts. The latter are known to possess a much higher photosynthetic capacity and a different pigment composition as compared to shade-type chloroplasts of shaded green leaves. Special consideration was given to the natural drought stress effects usually occurring in the summer period (ca. end of July to end of August), caused by a combination of unfavourable weather conditions, such as a longer heat stress, with strong solar radiation and a very low rain precipitation lying clearly below the annual mean. The obtained research results provided new facts for a better understanding of the physiology of photosynthesis in sun and shade leaves of beech at both normal physiological conditions (June) and at environmental stress conditions (July, August), as well as the effect of anthocyanins on the formation of sun-type chloroplasts and their photosynthetic pigments (chlorophylls and carotenoids) in light-exposed purple foliage. (orig.)

  9. Fathers on Parental Leave in Denmark

    DEFF Research Database (Denmark)

    Reinicke, Kenneth; Cybulski, Franz Wilhelm; Drews, Lea Vedel;

    2005-01-01

    In the article it is argued that contemporary fatherhood and masculinity differ increasingly from hegemonic masculinity according to which men are primarily responsible for ensuring the financial basis of the family. The article “Fathers on Parental Leave in Denmark”, based on interviews with 15 ......, parental leave and domestic affairs. The article also demonstrates that the issue of parental leave may cause a conflict of interest between an employer and en employee although the majority of employers in this study emphasize that parental leave is unproblematic for them....

  10. Leaf morphology of 89 tree species from a lowland tropical rain forest (Atlantic forest) in South Brazil

    OpenAIRE

    Maria Regina Torres Boeger; Luiz Carlos Alves; Raquel Rejane Bonatto Negrelle

    2004-01-01

    We examined the leaf morphology and anatomy of 89 tree species growing in an area of coastal Atlantic Forest in South Brazil. The majority of the species (> 75%) had small (notophyll and microphyll) elliptical simple leaves with entire margins. These leaves presented a typical anatomical structure consisting of a single epidermal cell layer, single palisade parenchyma cell layer, and spongy parenchyma with 5 to 8 cell layers. The sclerenchyma was limited to the vascular bundles. The majority ...

  11. Improving flavonoid extraction from Ginkgo biloba leaves by prefermentation processing.

    Science.gov (United States)

    Wang, Jiahong; Cao, Fuliang; Su, Erzheng; Wu, Caie; Zhao, Linguo; Ying, Ruifeng

    2013-06-19

    This paper presents a prefermentation treatment method involving fungi to improve flavonoid extraction from the leaves of Ginkgo biloba . The fungi employed for this treatment were screened from the soil present under an ancient ginkgo tree. Seventy-six strains belonging to 23 genera were isolated and identified by a molecular identification method employing 18S rDNA sequences. Thirty-three strains grew well using ginkgo leaves as the growth medium. One strain, Gyx086, with higher extracted yield of flavonoids and more similar to the control, was finally selected for prefermentation processing. The major fermentation factors were optimized by response surface methodology. The optimal conditions for the highest total falvonoid yield were 27.8 °C for temperature, 64.2% for moisture content, and 61 h for fermentation time. Under the optimal condition, a actual total flavonoid yield of 27.59 ± 0.52 mg/g dry weight culture sample was obtained, which was about 70% higher than that of unfermented gingko leaf samples.

  12. Microhabitat heterogeneity across leaves and flower organs promotes bacterial diversity.

    Science.gov (United States)

    Junker, Robert R; Keller, Alexander

    2015-09-01

    Eukaryote-associated microbiomes interact with their hosts in multiple manners, thereby affecting the hosts' phenotype, physical condition and behaviour. In plants, bacteria have numerous functions, with variable net effects, both in natural and agricultural systems. However, information about the composition and diversity of the bacterial communities associated with different aboveground plant organs, particularly flowers, is lacking. In addition, the relative effects of microhabitat and environmental conditions on community establishment require further attention. Here, using culture-independent methods, we determine that leaves and three floral microhabitats (nectar, stamina and styles) of Metrosideros polymorpha (Myrtaceae), a tree endemic to Hawai'i, host unique indicator communities composed of relatively abundant bacterial taxa. These indicator communities are accompanied by a large number of ubiquitous or rare bacteria with lower abundances. In our study system, the strong effect of microhabitat filtering on plant-associated community composition and bacterial richness and diversity strongly exceeds the influence of environmental effects such as precipitation, altitude, substrate age and geographic distance. Thus, the bacterial richness of aboveground plant organs is strongly underestimated when only one microhabitat, e.g. leaves, is considered. Our study represents a first step towards a comprehensive characterization of the distribution, composition and underlying factors, of plant bacterial communities, with implications for future basic and applied research on plant health, pollination and reproduction. PMID:26253507

  13. Uptake, metabolism, accumulation and toxicity of cyanide in willow trees

    DEFF Research Database (Denmark)

    Larsen, Morten; Ucisik, Ahmed Süheyl; Trapp, Stefan

    2005-01-01

    Chemicals taken up into plants may be accumulated so leading to toxic effects. Uptake and phytotoxicity of free cyanide was determined with the willow-tree transpiration test. Willow sets were grown in sand and irrigated with varying levels of cyanide (CN). Toxicity was determined by measuring...... tissue was observed at 40 and 50 mg/L. The kinetics of metabolism of cyanide by roots, stems and leaves of willows was determined by the closed-bottle metabolism test. The Michaelis−Menten parameters vmax and KM (maximal metabolic velocity and half-saturation constant, respectively) were determined...

  14. Associational resistance protects mangrove leaves from crab herbivory

    Science.gov (United States)

    Erickson, Amy A.; Bell, Susan S.; Dawes, Clinton J.

    2012-05-01

    While associational defenses have been well documented in many plant and algal ecosystems, this study is the first to document associational resistance in mangroves. Mangrove tree crab (Aratus pisonii) density and herbivory on three life-stages of the red mangrove (Rhizophora mangle) were documented in pure red versus mixed-species and predominantly non-red mangrove stands containing black (Avicennia germinans) and white (Laguncularia racemosa) mangroves in 1999-2000 in Tampa Bay, Florida. This study first established that R. mangle is the focal species in the context of associational resistance because it is damaged more than either of the other mangrove species. Next, it was hypothesized that crab density and leaf damage on R. mangle would be lower when in mixed-species and predominantly non-red versus red mangrove stands. A non-significant trend suggested that crab density varies among stands, and crab damage on R. mangle leaves was significantly lower in mixed-species and non-red stands. Mechanisms to explain associational resistance were examined. Positive Pearson correlations between the percent of adult R. mangle in a stand and both crab density and R. mangle leaf damage provided support for the resource concentration hypothesis. Limited support was found for the attractant-decoy hypothesis because the total amount of damaged leaves of all mangrove species combined typically differed among stands, suggesting that crabs were not shifting to alternative mangrove species to offset reduced availability of R. mangle leaves. Finally, while R. mangle seedlings were shorter in non-red stands compared to others, intra-specific differences in R. mangle leaf chemistry and sclerophylly among stands failed to explain associational patterns. These combined results argue for the need for additional experiments to elucidate mechanisms responsible for defensive plant associations in mangrove ecosystems and to determine whether such associations could be of use in mangrove

  15. Spanning Trees in Random Satisfiability Problems

    OpenAIRE

    Ramezanpour, A.; Moghimi-Araghi, S.

    2005-01-01

    Working with tree graphs is always easier than with loopy ones and spanning trees are the closest tree-like structures to a given graph. We find a correspondence between the solutions of random K-satisfiability problem and those of spanning trees in the associated factor graph. We introduce a modified survey propagation algorithm which returns null edges of the factor graph and helps us to find satisfiable spanning trees. This allows us to study organization of satisfiable spanning trees in t...

  16. Are There Infinite Irrigation Trees?

    Science.gov (United States)

    Bernot, M.; Caselles, V.; Morel, J. M.

    2006-08-01

    In many natural or artificial flow systems, a fluid flow network succeeds in irrigating every point of a volume from a source. Examples are the blood vessels, the bronchial tree and many irrigation and draining systems. Such systems have raised recently a lot of interest and some attempts have been made to formalize their description, as a finite tree of tubes, and their scaling laws [25], [26]. In contrast, several mathematical models [5], [22], [10], propose an idealization of these irrigation trees, where a countable set of tubes irrigates any point of a volume with positive Lebesgue measure. There is no geometric obstruction to this infinitesimal model and general existence and structure theorems have been proved. As we show, there may instead be an energetic obstruction. Under Poiseuille law R(s) = s -2 for the resistance of tubes with section s, the dissipated power of a volume irrigating tree cannot be finite. In other terms, infinite irrigation trees seem to be impossible from the fluid mechanics viewpoint. This also implies that the usual principle analysis performed for the biological models needs not to impose a minimal size for the tubes of an irrigating tree; the existence of the minimal size can be proven from the only two obvious conditions for such irrigation trees, namely the Kirchhoff and Poiseuille laws.

  17. Wading bird guano contributes to Hg accumulation in tree island soils in the Florida Everglades.

    Science.gov (United States)

    Zhu, Yingjia; Gu, Binhe; Irick, Daniel L; Ewe, Sharon; Li, Yuncong; Ross, Michael S; Ma, Lena Q

    2014-01-01

    Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those in mid and tail region, and marsh soils. Hg concentrations in bird guano (286 μg kg(-1)) were significantly higher than those in mammal droppings (105 μg kg(-1)) and plant leaves (53 μg kg(-1)). In addition, Hg concentrations and δ(15)N values displayed positive correlation in soils influenced by guano. During 1998-2010, estimated annual Hg deposition by guano was 148 μg m(-2) yr(-1) and ~8 times the atmospheric deposition. PMID:24080244

  18. Induction of hybrid decision tree based on post-discretization strategy

    Institute of Scientific and Technical Information of China (English)

    WANG Limin; YUAN Senmiao

    2004-01-01

    By redefining test selection measure, we propose in this paper a new algorithm, Flexible NBTree, which induces a hybrid of decision tree and Naive Bayes. Flexible NBTree mitigates the negative effect of information loss on test selection by applying postdiscretization strategy: at each internal node in the tree, we first select the test which is the most useful for improving classification accuracy, then apply discretization of continuous tests. The finial decision tree nodes contain univariate splits as regular decision trees, but the leaves contain Naive Bayesian classifiers. To evaluate the performance of Flexible NBTree, we compare it with NBTree and C4.5, both applying pre-discretization of continuous attributes. Experimental results on a variety of natural domains indicate that the classification accuracy of Flexible NBTree is substantially improved.

  19. Static terrestrial laser scanning of juvenile understory trees for field phenotyping

    Science.gov (United States)

    Wang, Huanhuan; Lin, Yi

    2014-11-01

    This study was to attempt the cutting-edge 3D remote sensing technique of static terrestrial laser scanning (TLS) for parametric 3D reconstruction of juvenile understory trees. The data for test was collected with a Leica HDS6100 TLS system in a single-scan way. The geometrical structures of juvenile understory trees are extracted by model fitting. Cones are used to model trunks and branches. Principal component analysis (PCA) is adopted to calculate their major axes. Coordinate transformation and orthogonal projection are used to estimate the parameters of the cones. Then, AutoCAD is utilized to simulate the morphological characteristics of the understory trees, and to add secondary branches and leaves in a random way. Comparison of the reference values and the estimated values gives the regression equation and shows that the proposed algorithm of extracting parameters is credible. The results have basically verified the applicability of TLS for field phenotyping of juvenile understory trees.

  20. Tree ecophysiological traits related to tree drought mortality are linked to the aridity of the environment in eucalypts

    Science.gov (United States)

    Arndt, S. K.; Sanders, G.; Hirsch, M.

    2013-12-01

    Increases in tree drought mortality are observed in forest ecosystems in all continents but the actual mechanisms how trees succumb to drought are still controversial. Physiological traits and thresholds have often be proposed as possible tools to predict tree drought mortality but these traits and thresholds have only been studied in a few tree species in detail. We investigated the vulnerability to hydraulic cavitation in leaves (P50leaf), turgor loss point (TLP) and osmotic potential at full turgor (OPFT) in 16 different eucalypts species that occur in environments of differing aridity in south-eastern Australia (gradient from 300mm to 1500 mm of precipitation per year). The species were grown from seed, planted in an arboretum in Melbourne and measured under well-watered conditions as two-year old saplings. We observed strong correlations between all measured ecophysiological traits and the aridity of the environment of the origin of the species. P50leaf and TLP were more negative in the eucalypts from more arid environments and more positive in eucalypts from more mesic environments, indicating that eucalypts in arid environments lose turgor at lower water potentials and have a lower vulnerability to hydraulic cavitation in leaves. Eucalypts from arid environments also had a much more negative osmotic potential at full turgor than eucalypts from mesic environments and more rigid cell walls. The measured plants all grew in the same environmental conditions and were well watered at the time of measurement. The results therefore indicate a strong genetic control over these physiological traits in eucalypts - trees from more arid environments lose turgor and hydraulic conductivity at lower water potentials and achieve these lower water potentials by having more osmotically active substances, even if they are not drought stressed. This is the first time these strong correlations between physiological traits and aridity of the origin of the species have been

  1. Counting spanning trees in graphs

    OpenAIRE

    Azarija, Jernej

    2012-01-01

    The history of counting the number of spanning trees dates back into the year 1842 in which the German mathematician Gustav Kirchhoff derived a relation between the number of spanning trees of a graph G (τ(G)) and the determinant of a specific submatrix associated with G. After this result many other related results followed. For example in 1889 the British mathematician A. Cayley showed that the complete graph on n nodes has nn−2 spanning trees.The function τ can nowadays be found in the fi...

  2. Trees Are Useful to Man

    Institute of Scientific and Technical Information of China (English)

    赵明

    2005-01-01

    Trees are useful to man in three impor-tant ways. They provide him with wood and other products;they give him shade;they help prevent drought(干旱)and floods. Unfortunately,in many parts of the world, man has not realized that the third one is the most important. Two thousand years ago a rich and pow-erful country cut down its trees to build war-ships, with which to gain itself an empire. It gained the empire,however,without its trees, its soil became hard and poor. When the em-pire fell to pieces, the home c...

  3. Proximate composition and mineral content of two edible species of Cnidoscolus (tree spinach).

    Science.gov (United States)

    Kuti, J O; Kuti, H O

    1999-01-01

    Proximate composition and mineral content of raw and cooked leaves of two edible tree spinach species (Cnidoscolus chayamansa and C. aconitifolius), known locally as 'chaya', were determined and compared with that of a traditional green vegetable, spinach (Spinicia oleraceae). Results of the study indicated that the edible leafy parts of the two chaya species contained significantly (p0.05) differences were found in nutritional composition and mineral content between the chaya species, except minor differences in the relative composition of fatty acids, protein and amino acids. Cooking of chaya leaves slightly reduced nutritional composition of both chaya species. Cooking is essential prior to consumption to inactivate the toxic hydrocyanic glycosides present in chaya leaves. Based on the results of this study, the edible chaya leaves may be good dietary sources of minerals (Ca, K and Fe) and vitamins (ascorbic acid and beta-carotene). PMID:10540979

  4. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees

    Science.gov (United States)

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees. PMID:27764099

  5. Trees as bioindicator of heavy metal pollution in three European cities

    International Nuclear Information System (INIS)

    Concentrations of four heavy metals were determined in tree leaves and bark collected from polluted and non-polluted areas of three European cities (Salzburg, Belgrade and Thessaloniki) for a comparative study. Platanus orientalis L. and Pinus nigra Arn., widespread in urban northern and southern Europe, were tested for their suitability for air quality biomonitoring. Leaves and barks were collected uniformly of an initial quantity of about 30 g of each sample. Analysis was accomplished by electrothermal atomic absorption spectrometry after total digestion. Site-dependent variations were found with the highest concentration level measured in Belgrade, followed by Thessaloniki and Salzburg. A higher accumulation of heavy metals was found in bark compared to leaves. Pine tree bark, accumulating higher concentrations of trace metals compared to plane tree bark, shows a higher efficiency as bioindicator for urban pollution. Both indicator species are suitable for comparative studies on bioindication of urban air pollution. - Highlights: → Oriental plane and Austrian pine are suitable for comparative urban air quality biomonitoring of heavy metal pollution. → Pine tree is excellently suitable as urban bioindicator as it accumulates high concentrations of trace metals. → The highest heavy metal pollution was found in Belgrade followed by Thessaloniki and Salzburg. - Oriental plane (Platanus orientalis L.) and Austrian pine (Pinus nigra Arn.), widespread in urban northern and southern Europe, are suitable for comparative biomonitoring of urban air pollution.

  6. Trees as bioindicator of heavy metal pollution in three European cities

    Energy Technology Data Exchange (ETDEWEB)

    Sawidis, T. [Department of Botany, University of Thessaloniki, 54124 Thessaloniki (Greece); Breuste, J., E-mail: juergen.breuste@sbg.ac.at [Department of Geography and Geology, University of Salzburg, 5010 Salzburg (Austria); Mitrovic, M.; Pavlovic, P. [Department of Ecology, Institute for Biological Research ' Sinisa Stankovic' , University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade (Serbia); Tsigaridas, K. [Department of Botany, University of Thessaloniki, 54124 Thessaloniki (Greece)

    2011-12-15

    Concentrations of four heavy metals were determined in tree leaves and bark collected from polluted and non-polluted areas of three European cities (Salzburg, Belgrade and Thessaloniki) for a comparative study. Platanus orientalis L. and Pinus nigra Arn., widespread in urban northern and southern Europe, were tested for their suitability for air quality biomonitoring. Leaves and barks were collected uniformly of an initial quantity of about 30 g of each sample. Analysis was accomplished by electrothermal atomic absorption spectrometry after total digestion. Site-dependent variations were found with the highest concentration level measured in Belgrade, followed by Thessaloniki and Salzburg. A higher accumulation of heavy metals was found in bark compared to leaves. Pine tree bark, accumulating higher concentrations of trace metals compared to plane tree bark, shows a higher efficiency as bioindicator for urban pollution. Both indicator species are suitable for comparative studies on bioindication of urban air pollution. - Highlights: > Oriental plane and Austrian pine are suitable for comparative urban air quality biomonitoring of heavy metal pollution. > Pine tree is excellently suitable as urban bioindicator as it accumulates high concentrations of trace metals. > The highest heavy metal pollution was found in Belgrade followed by Thessaloniki and Salzburg. - Oriental plane (Platanus orientalis L.) and Austrian pine (Pinus nigra Arn.), widespread in urban northern and southern Europe, are suitable for comparative biomonitoring of urban air pollution.

  7. Implementing Municipal Tree Planting: Los Angeles Million-Tree Initiative

    OpenAIRE

    Pincetl, Stephanie

    2010-01-01

    Urban forests are increasingly being seen as an important infrastructure that can help cities remediate their environmental impacts. This work reports on the first steps in implementing a million tree program in Los Angeles and the ways such a biogenic—living—infrastructure has been approached. Numbers of studies have been done to quantify the benefits of urban forests, but little has been written on the process of implementing urban tree planting programs. The investigative methods were prim...

  8. The elm, tree of milk and wine

    Directory of Open Access Journals (Sweden)

    Heybroek HM

    2015-04-01

    Full Text Available Elm has played an important role in European culture for thousands of years, in many roles, with regional variation. In material culture, its wood has assisted in hunting and warfare for over seven thousand years; but more importantly, its leaves and bark were semi-indispensible for the production of milk and meat, and served as an emergency food for humans. In the Mediterranean, elm was the main tool for the production of a good quality wine by providing support for the grapevine, and it helped feeding the cattle. These functions sometimes found an echo in the non-material culture. The fact that in Germanic genesis stories the first woman was created out of an elm (the man out of an ash, as well as a severe local taboo on the use of elm wood for skis, threatening the offender with a place in hell, seem both connected to the superior feeding value of this tree. In England and in parts of continental Europe most sacred trees were elms, sometimes performing female functions such as the production of babies. In the Mediterranean, however, the elm was seen as the male partner in the “marriage of the vine to the elm”, which was the celebrated system of viticulture. That image has been used by poets and politicians over the ages to praise the effects of human marriage, cooperation and interdependence. It even forms the core of the apocryphal Bible book “The Shepherd”, where it is seen as a symbol and example for a kind of symbiosis between the rich and the poor. - In conclusion, the ultimate origin of the English elm or “Atinia”, as well as its discovery is discussed, which appears to be a question of milk and wine.

  9. A new class of non-leaves

    CERN Document Server

    Souza, Fábio S

    2011-01-01

    We give examples of open smooth manifolds that cannot be leaves of any Riemannian foliation of arbitrary codimension on a compact manifold. We also present a new class of non-leaves of C^0 codimension one foliations, simply connected manifolds of dimension at least 5 that are non-periodic in homotopy, namely in their 2-dimensional homotopy groups.

  10. When and Why Dropouts Leave High School

    Science.gov (United States)

    Stearns, Elizabeth; Glennie, Elizabeth J.

    2006-01-01

    Teens may leave school because of academic failure, disciplinary problems, or employment opportunities. In this article, the authors test whether the reasons dropouts leave school differ by grade level and age. We compare dropout rates and reasons across grade levels and ages for all high school students, ethnic groups, and gender groups. Across…

  11. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Document Server

    DIVISION HR

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programs) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave. They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leave a...

  12. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Multimedia

    DIVISION HR; TEL. 74474

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programmes) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave. They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system 1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leav...

  13. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Document Server

    HR Division

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programmes) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave.They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system 1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leave...

  14. A Feminist Perspective on Parental Leave Policies

    Science.gov (United States)

    Sallee, Margaret W.

    2008-01-01

    This article focuses on the ways that three feminist theories--liberal feminism, cultural feminism, and feminist poststructuralism--might be used to craft parental leave policies. After examining each theory in detail, the article concludes by offering one example of an ideal parental leave policy that combines the best features of each theory to…

  15. 20 CFR 638.532 - Annual leave.

    Science.gov (United States)

    2010-04-01

    ... regardless of the date of enrollment provided that the student was not AWOL or on administrative leave without pay from the date of enrollment. Accrual time shall begin on the day the student departs for a... only once per year of enrollment. (e) Students shall not be charged annual leave for travel time to...

  16. Transpiration of urban trees and its cooling effect in a high latitude city

    Science.gov (United States)

    Konarska, Janina; Uddling, Johan; Holmer, Björn; Lutz, Martina; Lindberg, Fredrik; Pleijel, Håkan; Thorsson, Sofia

    2016-01-01

    An important ecosystem service provided by urban trees is the cooling effect caused by their transpiration. The aim of this study was to quantify the magnitude of daytime and night-time transpiration of common urban tree species in a high latitude city (Gothenburg, Sweden), to analyse the influence of weather conditions and surface permeability on the tree transpiration, and to find out whether tree transpiration contributed to daytime or nocturnal cooling. Stomatal conductance and leaf transpiration at day and night were measured on mature street and park trees of seven common tree species in Gothenburg: Tilia europaea, Quercus robur, Betula pendula, Acer platanoides, Aesculus hippocastanum, Fagus sylvatica and Prunus serrulata. Transpiration increased with vapour pressure deficit and photosynthetically active radiation. Midday rates of sunlit leaves ranged from less than 1 mmol m-2 s-1 ( B. pendula) to over 3 mmol m-2 s-1 ( Q. robur). Daytime stomatal conductance was positively related to the fraction of permeable surfaces within the vertically projected crown area. A simple estimate of available rainwater, comprising of precipitation sum and fractional surface permeability within the crown area, was found to explain 68 % of variation in midday stomatal conductance. Night-time transpiration was observed in all studied species and amounted to 7 and 20 % of midday transpiration of sunlit and shaded leaves, respectively. With an estimated night-time latent heat flux of 24 W m-2, tree transpiration significantly increased the cooling rate around and shortly after sunset, but not later in the night. Despite a strong midday latent heat flux of 206 W m-2, a cooling effect of tree transpiration was not observed during the day.

  17. Implementing Municipal Tree Planting: Los Angeles Million-Tree Initiative

    Science.gov (United States)

    Pincetl, Stephanie

    2010-02-01

    Urban forests are increasingly being seen as an important infrastructure that can help cities remediate their environmental impacts. This work reports on the first steps in implementing a million tree program in Los Angeles and the ways such a biogenic—living—infrastructure has been approached. Numbers of studies have been done to quantify the benefits of urban forests, but little has been written on the process of implementing urban tree planting programs. The investigative methods were primarily qualitative, involving interviews, attending meetings and conducting literature reviews. Results indicate that multiple nonprofit and city agency programs are involved in planting and maintaining trees and this has required coordination among groups that here-to-fore were unaccustomed to having to collaborate. The main finding that emerge from this research is that the implementation of such a program in Los Angeles is more complicated than it may seem due to several interacting factors: the need to rely on multiple public and private organizations to put trees into the ground and to maintain them; coordination of these multiple efforts must be centralized, but requires a great deal of time and effort and maybe resisted by some of the partners; funding for planting and long term maintenance must be pieced together from multiple sources; acceptance of trees by residents varies by neighborhood as does tree canopy cover; appropriate nursery supply can be limited; the location of the program within the city administration is determined by who initiates the program.

  18. Implementing municipal tree planting: Los Angeles million-tree initiative.

    Science.gov (United States)

    Pincetl, Stephanie

    2010-02-01

    Urban forests are increasingly being seen as an important infrastructure that can help cities remediate their environmental impacts. This work reports on the first steps in implementing a million tree program in Los Angeles and the ways such a biogenic-living-infrastructure has been approached. Numbers of studies have been done to quantify the benefits of urban forests, but little has been written on the process of implementing urban tree planting programs. The investigative methods were primarily qualitative, involving interviews, attending meetings and conducting literature reviews. Results indicate that multiple nonprofit and city agency programs are involved in planting and maintaining trees and this has required coordination among groups that here-to-fore were unaccustomed to having to collaborate. The main finding that emerge from this research is that the implementation of such a program in Los Angeles is more complicated than it may seem due to several interacting factors: the need to rely on multiple public and private organizations to put trees into the ground and to maintain them; coordination of these multiple efforts must be centralized, but requires a great deal of time and effort and maybe resisted by some of the partners; funding for planting and long term maintenance must be pieced together from multiple sources; acceptance of trees by residents varies by neighborhood as does tree canopy cover; appropriate nursery supply can be limited; the location of the program within the city administration is determined by who initiates the program. PMID:20016982

  19. Decomposition and nutrient release in leaves of Atlantic Rainforest tree species used in agroforestry systems

    NARCIS (Netherlands)

    Duarte, E.M.G.; Cardoso, I.M.; Stijnen, T.; Mendonça, M.A.F.C.; Coelho, M.S.; Cantarutti, R.B.; Kuyper, T.W.; Villani, E.M.A.; Mendonça, E.S.

    2013-01-01

    Aiming to support the use of native species from the Atlantic Rainforest in local agroforestry systems, we analysed chemical and biochemical components related to leaf decomposition of Inga subnuda, Senna macranthera, Erythrina verna, Luehea grandiflora, Zeyheria tuberculosa, Aegiphila sellowiana, a

  20. A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer tree species.

    Science.gov (United States)

    Johnson, Daniel M; Wortemann, Remi; McCulloh, Katherine A; Jordan-Meille, Lionel; Ward, Eric; Warren, Jeffrey M; Palmroth, Sari; Domec, Jean-Christophe

    2016-08-01

    Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-tree hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature tree trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are nonredundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf and xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer tree species. Across all species, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-tree vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many species. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. This study also highlights the necessity for more research of whole-plant hydraulic physiology to better