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Growth of ten multipurpose tree species on acid soils in Sangmelima, Cameroon  

Microsoft Academic Search

Ten multipurpose tree species were planted both in monoculture and intercropped withArachis hypogea (groundnut) in a randomized complete block with three replications. The vigrou, biomass, nutrient content, and coppicing percentage of the trees were evaluated. Intercropping with groundnuts during the establishment phase did not affect subsequent growth and development of the species.Acacia mangium, Acacia auriculiformis, Cassia siamea, Calliandra calothyrsus andParaserianthes

B. Duguma; J. Tonye; J. Kanmegne; T. Manga; T. Enoch




Microsoft Academic Search

A field study was conducted at NIA experimental farm, Tandojam to observe the growth and nutrients (macro and micro) content of some salt tolerant multipurpose tree species (Acacia ampliceps, Acacia stenophylla, Acacia nilotica, Eucalyptus camaldulensis, and Conocarpus lancifolius) under saline environment. The salinity of the soil was varying from medium saline to very highly saline. The growth performances recorded at



Ameliorative Effect of Multipurpose Tree Species Grown on Sodic Soils of Indo-Gangetic Alluvial Plains of India  

Microsoft Academic Search

A Long-term field study was carried out to compare the impact of ten-year old plantation of ten multipurpose tree species, viz., Terminalia arjuna, Azadirachta indica, Prosopis juliflora, Pongamia pinnata, Casuarina equisetifolia, Prosopis alba, Acacia nilotica, Eucalyptus tereticornis, Pithecellobium dulce, and Cassia siamea on tree growth, biomass yield, and physico-chemical properties of sodic soils representing major tract of salt-affected soils of

Y. P. Singh; Gurbachan Singh; D. K. Sharma



Biomass and bio-energy production of ten multipurpose tree species planted in sodic soils of indo-gangetic plains  

Microsoft Academic Search

Ten multipurpose tree species, Terminalia arjuna, Azadirechta indica, Prosopis juliflora, Pongamia pinnata, Casuarina equisetifolia, Prosopis alba, Acacia\\u000a nilotica, Eucalyptus tereticornis, Pithecellobium dulce and Cassia siamea, were raised in a monoculture tree cropping system on the sodic soil of Gangetic alluvium in north India (26° 47? N: 80°46?\\u000a E) for 10 years to evaluate the biomass and bio-energy production. The soil

Y. P. Singh; Gurbachan Singh; D. K. Sharma



Vegetative and reproductive phenology of some multipurpose tree species in the homegardens of Barak Valley, northeast India.  


Traditional homegardens are an important component of the farming systems in many rural communities and have been highlighted considerably due to their sustainability and role in the conservation of biodiversity. However, the functional aspect of the homegardens, which includes the phenological behavior of the dominant tree species in such agroforestry systems, has been undermined till date, and there is a lack of adequate data on this aspect of the traditional homegardens. As a step in this direction the present study was carried out to determine the phenological behavior of important multipurpose trees in the homegardens of the village of Dargakona, Assam, northeast India. The study revealed the dominance of periodic growth deciduous species from a total of 25 tree species selected for phenological observation. The diversity of multipurpose trees in the homegardens is represented by different plant functional types with different phenological behavior which showed significant changes in their responses to inter-annual climatic variations. The diversity of tree species with different phenological behavior has implications for the temporal partitioning of resources, especially during periods of scarcity, thereby resulting in efficient utilization of resources such as water. Also the diverse phenological behavior plays an important role in regulating the food supply for the herbivore population and the year-round availability of products, and such information can be useful in the selection of species for integration into other agroforestry systems which can be sustainable in the long run. PMID:22555388

Das, Tapasi; Das, Ashesh Kumar



Effective information management in forestry: An application to fuel wood and multi-purpose tree species research in Central America  

SciTech Connect

The main goals of this study were: (a) the development of a methodology to collect and organize silvicultural and environmental information in forestry research on fuel wood and multi-purpose tree species (MPTS) production, and (b) the design of a Management Information System (MIS) to supply decision-support for different end-users. This study was supported by a project of USAID for fuel wood research in six Central American countries. Uniform standards and guidelines for implementing fuel wood and MPTS experiments were established in order to permit global exchange and transfer of information on MPTS research. These standards for data collection and field measurements, and minimum data sets were developed in coordination with scientists to ensure the collection of useful information and to gain acceptance of these standards. The minimum data sets were developed to reflect what can be achieved at a reasonable logistic expense with an acceptable degree of consistency. Establishment of MPTS information data bases will permit improvement in all phases of forest management, including seed procurement and species selection for environmental zones.

Ugalde Arias, L.A.



Effects of species and season on chemical composition and ruminal crude protein and organic matter degradability of some multi-purpose tree species by West African dwarf rams.  


Seasonal chemical composition and ruminal organic matter (OM) and crude protein (CP) degradabilities were determined in four tropical multi-purpose tree species (MPTS) namely; Pterocarpus santalinoides, Grewia pubescens, Enterolobium cyclocarpum and Leucaena leucocephala. Three West African dwarf (WAD) rams fitted with permanent rumen cannula were used for the degradability trials. Foliage samples were collected four times to represent seasonal variations as follows: January--mid dry; April--late dry; July--mid rainy and October--late rainy seasons. Leaf samples were randomly collected from the trees for estimation of dry matter (DM) and chemical composition. Ruminal in sacco OM and CP degradabilities were estimated from residues in nylon bags. All samples had high CP (161-259 g/kg DM) and moderate fibre concentrations [neutral detergent fibre (without residual ash], 300-501 g/kg DM; acid detergent fibre (without residual ash), 225-409 g/kg DM and acid detergent lignin, 87-179 g/kg DM across seasons. Interaction effects of species and season on chemical composition were highly significant (p = 0.001) except for trypsin inhibitor (p = 0.614). The MPTS recorded more than 60% OM and CP degradability at 24 h, which implied that they were all highly degradable in the rumen. Their incorporation into ruminant feeding systems as dry season forage supplements is therefore recommended. PMID:21535229

Arigbede, O M; Anele, U Y; Südekum, K-H; Hummel, J; Oni, A O; Olanite, J A; Isah, A O



Nutritional and anti-nutritional characters and rumen degradability of dry matter and nitrogen for some multipurpose tree species with potential for agroforestry in Zimbabwe  

Microsoft Academic Search

In a preliminary study on the nutritional value of seven multipurpose trees (MPTs), currently showing potential use in agroforestry systems in Zimbabwe, crude protein values ranged from 189 g kg?1 DM in Flemingia macrophylla to 292 g kg?1 DM in Acacia angustissima. Acid detergent fibre (ADF) content was low especially in Sesbania sesban (99 g kg?1 DM), while ADF contents

B. H. Dzowela; L. Hove; J. H. Topps; P. L. Mafongoya



Fifth International Poplar Symposium: 'Poplars and willows: from research models to multipurpose trees for a bio-based society'.  


Carefully managed tree plantations offer an opportunity for sustainable biomass production. In recent years, the responses of the Salicaceae to environmental constraints have increasingly been investigated at different levels of biological integration, giving rise to a physiological approach to the function of trees in environmental restoration and monitoring. Significant progress has been achieved by the poplar and willow community in understanding targeted characteristics of complex tree stress responses. The Fifth International Poplar Symposium brought together experts in this area, with the main objective being to improve, coordinate and communicate existing national research on the biological and environmental dimension of multifunctional poplar and willow plantations. The secondary objective was to develop a network of research scientists and extension workers to provide scientific support for subjects interested in using fast-growing poplar and willow species for tree-related environmental projects. The ultimate goal was to build up services for the multipurpose tree plantation network on local-level management in order to obtain maximized benefits from tree crops. The purpose was also to maximize the synergy between local knowledge and global-level processes that require information on multipurpose tree crop production. PMID:22158009

Tognetti, Roberto; Massacci, Angelo; Mugnozza, Giuseppe Scarascia



Acacia albida and other multipurpose trees on the fur farmlands in the Jebel Marra highlands, Western Darfur, Sudan  

Microsoft Academic Search

This paper describes the traditional agroforestry systems based on Acacia albida and other multipurpose trees as practised by the sedentary Fur people on the lower slopes and highlands of the Jebel Marra massif, Sudan. The basic agrosilvopastoral system consists of terraced village fields, where semipermanent rainfed cropping of staple millet and other subsistence crops takes place under stands of multipurpose

S. Miehe




Microsoft Academic Search

Capparis decidua (Forsk) Edgew. is an under-exploited, drought hardy, multipurpose, woody shrub or small tree found throughout arid regions of Indian sub-continent. It is of great value to the inhabitants in a variety of ways. The green immature fruits are rich in protein, carbohydrates, fats and minerals (Ca, P & Fe); immature fruits are either pickled or made into a




Discordance of Species Trees with Their Most Likely Gene Trees  

Microsoft Academic Search

Because of the stochastic way in which lineages sort during speciation, gene trees may differ in topology from each other and from species trees. Surprisingly, assuming that genetic lineages follow a coalescent model of within-species evolution, we find that for any species tree topology with five or more species, there exist branch lengths for which gene tree discordance is so

James H. Degnan; Noah A. Rosenberg



Removal of chromium by some multipurpose tree seedlings of Indian thar desert.  


An experiment was conducted to study the potential of chromium (Cr) phytoaccumulatory capabilities of four tree species viz., Anogeissus latifolia, Terminalia arjuna, Tecomella undulata, and Salvadora persica Possibility of enhancement of Cr uptake by citric acid and vesicular arbuscular mycorrhizal fungi (VAM) amendments were also tried. Cr is a major pollutant of the environment. Chromium can exist in oxidation states from III to VI, but the most stable and common forms of Cr are trivalent and hexavalent species. Cr(VI) was more toxic to the tree growth in terms of collar diameter (CD) increment in all the tree species than Cr(lll). Roots accumulated more Cr than shoots in all the tree species. There was more than 10 fold increase in root Cr content in comparison with shoot Cr content in all the trees at all the concentration of Cr and all sources of Cr. Citric acid significantly increased the Cr content in the tissues of roots in all the species under both speciation of Cr. The highest increase in Cr content brought by 20 mM citric acid addition was in A. latifolia Results suggest that Anogeissus latifolia is a potential Cr accumulator with citric acid as soil amendment. PMID:21166349

Mathur, Nishi; Singh, Joginder; Bohra, Sachendra; Bohra, Avinash; Vyas, Anil


The Probability of Topological Concordance of Gene Trees and Species Trees  

Microsoft Academic Search

The concordance of gene trees and species trees is reconsidered in detail, allowing for samples of arbitrary size to be taken from the species. A sense of concordance for gene tree and species tree topologies is clarified, such that if the “collapsed gene tree” produced by a gene tree has the same topology as the species tree, the gene tree

Noah A. Rosenberg



From event-labeled gene trees to species trees  

PubMed Central

Background Tree reconciliation problems have long been studied in phylogenetics. A particular variant of the reconciliation problem for a gene tree T and a species tree S assumes that for each interior vertex x of T it is known whether x represents a speciation or a duplication. This problem appears in the context of analyzing orthology data. Results We show that S is a species tree for T if and only if S displays all rooted triples of T that have three distinct species as their leaves and are rooted in a speciation vertex. A valid reconciliation map can then be found in polynomial time. Simulated data shows that the event-labeled gene trees convey a large amount of information on underlying species trees, even for a large percentage of losses. Conclusions The knowledge of event labels in a gene tree strongly constrains the possible species tree and, for a given species tree, also the possible reconciliation maps. Nevertheless, many degrees of freedom remain in the space of feasible solutions. In order to disambiguate the alternative solutions additional external constraints as well as optimization criteria could be employed.




Microsoft Academic Search

Studies on rooting patterns of eight important multipurpose tree species demonstrated large variation in root depth and horizontal root spread 5 year after planting. The root depth varied between 1.01m (Acacia lenticularis L.) and 2.71m (Acacia nilotica (L.) Willd ex. Del.). Variation in horizontal root spread was 1.69m in Syzygium cumini (L.) and 7.70m in Pithecellobium dulce (Roxb.) Benth…Root spread




Discordance of Species Trees with Their Most Likely Gene Trees: The Case of Five Taxa  

Microsoft Academic Search

Under a coalescent model for within-species evolution, gene trees may differ from species trees to such an extent that the gene tree topology most likely to evolve along the branches of a species tree can disagree with the species tree topology. Gene tree topologies that are more likely to be produced than the topology that matches that of the species




Effect of supplementation of maize stover with foliage of various tropical multipurpose trees and Lablab purpureus on intake, rumen fermentation, digesta kinetics and microbial protein supply of sheep  

Microsoft Academic Search

Foliage of four multipurpose trees (Calliandra calothyrsus, Chamaecytisus palmensis, Leucaena diversifolia and Vernonia amygdalina) and a woody leguminous perennial (Lablab purpureus) were evaluated for their potential as protein supplements for sheep fed maize stover ad libitum. The chemical composition of the feed was analysed, and maize stover degradation, rumen kinetics, passage rate were measured and enumeration of microbial population in

I. K Hindrichsen; P. O Osuji; A. A Odenyo; J Madsen; T Hvelplund



In vitro and in situ evaluation of selected multipurpose trees, wheat bran and Lablab purpureus as potential feed supplements to tef ( Eragrostis tef) straw  

Microsoft Academic Search

In vitro and in situ evaluations of feed samples were carried out at Debre Zeit Research Station (Ethiopia) of the International Livestock Research Institute. The feed samples consisted of tef straw, wheat bran, dried Lablab purpureus, and dried foliage of the multipurpose trees (MPT), namely Sesbania sesban 1198, Sesbania sesban 15019, Acacia angustissima 15132, Leucaena pallida 14203, and mixtures of

Solomon Melaku; Kurt J Peters; Azage Tegegne



Predicting spacing effects on growth and optimal rotations of tropical multipurpose trees  

Microsoft Academic Search

In order to improve our ability to analyze growth of tropical fast-growing trees, we developed a simple model (MPTGro) to predict development of even-aged stands from allometric equations of leaf area and total biomass. and a competition index based on wood production per unit leaf area, or net assimilation rate (E). In this study we (1) tested te model assumption

Robin A. Harrington; James H. Fownes



A characterization of the set of species trees that produce anomalous ranked gene trees.  


Ranked gene trees, which consider both the gene tree topology and the sequence in which gene lineages separate, can potentially provide a new source of information for use in modeling genealogies and performing inference of species trees. Recently,we have calculated the probability distribution of ranked gene trees under the standard multispecies coalescent model for the evolution of gene lineages along the branches of a fixed species tree, demonstrating the existence of anomalous ranked gene trees (ARGTs), in which a ranked gene tree that does not match the ranked species tree can have greater probability under the model than the matching ranked gene tree. Here, we fully characterize the set of unranked species tree topologies that give rise to ARGTs, showing that this set contains all species tree topologies with five or more taxa, with the exceptions of caterpillars and pseudocaterpillars. The results have implications for the use of ranked gene trees in phylogenetic inference. PMID:22868677

Degnan, James H; Rosenberg, Noah A; Stadler, Tanja


Litter of multipurpose trees in Kerala, India: variations in the amount, quality, decay rates and release of nutrients  

Microsoft Academic Search

In a field study involving 8–9 year-old woodlots of nine fast growing tree species in Kerala, India, the amount and nutrient content of litterfall were monitored. Decay rate constants and litter half-lives were estimated by fitting a single exponential model to the litter decomposition data. Annual litter production ranged from 3.43Mgha?1 (Pterocarpus) to 12.69Mgha?1 (Acacia). Litterfall of Acacia, Ailanthus, Pterocarpus

V Jamaludheen; B. Mohan Kumar



Properties of Consensus Methods for Inferring Species Trees from Gene Trees  

PubMed Central

Consensus methods provide a useful strategy for summarizing information from a collection of gene trees. An important application of consensus methods is to combine gene trees to estimate a species tree. To investigate the theoretical properties of consensus trees that would be obtained from large numbers of loci evolving according to a basic evolutionary model, we construct consensus trees from rooted gene trees that occur in proportion to gene-tree probabilities derived from coalescent theory. We consider majority-rule, rooted triple (R*), and greedy consensus trees obtained from known, rooted gene trees, both in the asymptotic case as numbers of gene trees approach infinity and for finite numbers of genes. Our results show that for some combinations of species-tree branch lengths, increasing the number of independent loci can make the rooted majority-rule consensus tree more likely to be at least partially unresolved. However, the probability that the R* consensus tree has the species-tree topology approaches 1 as the number of gene trees approaches ?. Although the greedy consensus algorithm can be the quickest to converge on the correct species-tree topology when increasing the number of gene trees, it can also be positively misleading. The majority-rule consensus tree is not a misleading estimator of the species-tree topology, and the R* consensus tree is a statistically consistent estimator of the species-tree topology. Our results therefore suggest a method for using multiple loci to infer the species-tree topology, even when it is discordant with the most likely gene tree.

Degnan, James H.; DeGiorgio, Michael; Bryant, David; Rosenberg, Noah A.



A tree species inventory over Europe  

NASA Astrophysics Data System (ADS)

Atmospheric transport models are used in studies of atmospheric chemistry as well as aerobiology. Atmospheric transport models in general needs accurate emissions inventories, which includes biogenic emissions such as Volatile Organic Compounds (VOCs) and pollen. Trees are important VOC and pollen sources and a needed requirement is specie distribution which takes into account important species such as Betula and Alnus. We present here a detailed tree species inventory covering Europe, parts of Africa and parts of Asia. Forest inventories have been obtained for each European country, parts of Asia and parts of Africa. The national inventories vary with respect to number of species as well as the number of sub-regions each nation is divided into. The inventories are therefore harmonised within a GIS system and afterwards gridded to the model grid defined by the EMEP model: 50 km x 50 km. The inventory is designed to be used with existing land-use data, which separates forest cover into broad leaved, mixed and conifer forests. This will be exemplified by using two different remote sensing products with different grid resolution such as GLC2000 and CLC2000 in selected areas. The final inventory includes 16 conifer species and 23 broadleaved species that are important for biogenic VOCs or pollen emission calculations. For example: Oak (Quercus), poplar (Populus), pines (Pinus), spruce (Picea), birch (Betula) and alder (Alnus). 774 regions with forest inventories are included, mainly on sub-national level. The coverage of each specie ranges from national to European scale, where the latter includes VOC and allergy relevant species such as Quercus, Alnus and Betula. The inventory is gridded to the model grid defined by the EMEP model, which is also the basis for many emissions inventories throughout Europe. The inventory is therefore prepared for easy implementation into atmospheric transport models by providing an extension to already applied land use data such as the Corine Land Cover (CLC2000) or Global Land Cover (GLC2000). Possible applications of the inventory include emissions of VOCs and pollen, CO2 fluxes and dry deposition - in general calculations which are tree specie dependent.

Ambelas Skjøth, C.; Geels, C.; Hvidberg, M.; Hertel, O.; Brandt, J.; Frohn, L. M.; Hansen, K. M.; Hedegaard, G. B.; Christensen, J. H.; Moseholm, L.



DNA barcoding: species delimitation in tree peonies.  


Delimitations of species are crucial for correct and precise identification of taxa. Unfortunately "species" is more a subjective than an objective concept in taxonomic practice due to difficulties in revealing patterns of infra- or inter-specific variations. Molecular phylogenetic studies at the population level solve this problem and lay a sound foundation for DNA barcoding. In this paper we exemplify the necessity of adopting a phylogenetic concept of species in DNA barcoding for tree peonies (Paeonia sect. Moutan). We used 40 samples representing all known populations of rare and endangered species and several populations of widely distributed tree peonies. All currently recognized species and major variants have been included in this study. Four chloroplast gene fragments, i.e. ndhF, rps16-trnQ, trnL-F and trnS-G (a total of 5040 characters, 96 variable and 69 parsimony-informative characters) and one variable and single-copy nuclear GPAT gene fragment (2093-2197 bp, 279 variable and 148 parsimony-informative characters) were used to construct phylogenetic relationships among the taxa. The evolutionary lineages revealed by the nuclear gene and the chloroplast genes are inconsistent with the current circumscriptions of P. decomposita, P. jishanensis, P. qiui, and P. rockii based on morphology. The inconsistencies come from (1) significant chloroplast gene divergence but little nuclear GPAT gene divergence among population systems of P. decomposita + P. rockii, and (2) well-diverged nuclear GPAT gene but little chloroplast gene divergence between P. jishanensis and P. qiui. The incongruence of the phylogenies based on the chloroplast genes and the nuclear GPAT gene is probably due to the chloroplast capture event in evolutionary history, as no reproductive barriers exist to prevent inter-specific hybridization. We also evaluated the suitability of these genes for use as DNA barcodes for tree peonies. The variability of chloroplast genes among well-defined species or population systems of a species complex is 4.82 times the figure within the groups, and the GPAT gene is twice as variable between the groups as within the groups. The number of completely divergent sites is sufficient to mark the two subsections, the two species in subsection Delavayanae, and the well-divergent species in subsection Vaginatae. But the genes currently used either from the chloroplast genome or from the nuclear genome alone cannot correctly assign samples of P. decomposita, P. jishanensis, P. qiui, or P. rockii to the species as currently defined. We conclude that (1) DNA barcoding should be based on prior phylogenetic studies to understand the evolutionary lineages and how well the taxonomic species correspond to the lineages; (2) it is unlikely to find a single short fragment as a barcode for every plant and such a fragment could result in misidentification when a chloroplast capture event happened in the evolutionary history of plants like tree peonies; and (3) we suggest striving for a universal marker at the familial level and locally universal barcodes within a family instead of looking for a universal barcode for all plants. PMID:19557335

ZHANG, JinMei; WANG, JianXiu; XIA, Tao; ZHOU, ShiLiang



Flavanol binding of nuclei from tree species.  


Light microscopy was used to examine the nuclei of five tree species with respect to the presence of flavanols. Flavanols develop a blue colouration in the presence of a special p-dimethylaminocinnamaldehyde (DMACA) reagent that enables those nuclei loaded with flavanols to be recognized. Staining of the nuclei was most pronounced in both Tsuga canadensis and Taxus baccata, variable in Metasequoia glyptostroboides, faint in Coffea arabica and minimal in Prunus avium. HPLC analysis showed that the five species contained substantial amounts of different flavanols such as catechin, epicatechin and proanthocyanidins. Quantitatively, total flavanols were quite different among the species. The nuclei themselves, as studied in Tsuga seed wings, were found to contain mainly catechin, much lower amounts of epicatechin and traces of proanthocyanidins. Blue-coloured nuclei located centrally in small cells were often found to maximally occupy up to 90% of a cell's radius, and the surrounding small rim of cytoplasm was visibly free of flavanols. A survey of 34 gymnosperm and angiosperm species indicated that the first group has much higher nuclear binding capacities for flavanols than the second group. PMID:14595514

Feucht, W; Treutter, D; Polster, J



Isoprene emission capacity for US tree species  

NASA Astrophysics Data System (ADS)

Isoprene emission capacity measurements are presented from 18 North American oak ( Quercus) species and species from six other genera previously found to emit significant quantities of isoprene. Sampling was conducted at physiographically diverse locations in North Carolina, Central California, and Northern Oregon. Emissions from several sun leaves of each species were measured at or near standard conditions (leaf temperature of 30°C and photosynthetically active radiation of 1000 ?mol m -2 s -1) using environmentally controlled cuvette systems and gas chromatography with reduction gas detectors. Species mean emission capacity ranged from 39 to 158 ?g C g -1 h -1 (mean of 86), or 22 to 79 nmol m -2 s -1 (mean of 44). These rates are 2-28 times higher than those previously reported from the same species, which were summarized in a recent study where isoprene emission rates were assigned based on published data and taxonomy. These discrepancies were attributed to differences in leaf environment during development, measurement technique (branch or plant enclosure versus leaf enclosure), and lack of environmental measurements associated with some of the earlier branch enclosure measurements. Mass-based emission capacities for 15 of 18 oak species, sweetgum ( Liquidambar styraciflua), and poplars ( Populus trichocarpa and P. deltoides) were within ranges used in current biogenic volatile organic compound (BVOC) emission models, while measured rates for the remaining three oak species, Nyssa sylvatica, Platanus occidentalis, Robinia pseudoacacia, Salix nigra, and Populus hybrids ( Populus trichocarpa × P. deltoides) were considerably higher. In addition, mean specific leaf mass of the oak species was 30% higher than assumed in current emission models. Emission rates reported here and in other recent studies support recent conclusions that isoprene emission capacities for sun leaves of high emitting species may be better represented by a value of 100±50 ?g C g -1 h -1 during hot summer conditions. We also find that intermediate isoprene emission rates previously suggested for some tree species may not represent their true emission capacities, and that broadleaf plant species may have either low (<1.0 ?g C g -1 h -1) or very high (˜100 ?g C g -1 h -1) genetic capacity to emit isoprene when mature foliage is exposed to a high ambient temperature and light environment.

Geron, Chris; Harley, Peter; Guenther, Alex


Tree Species Diversity in Commercially Logged Bornean Rainforest  

Microsoft Academic Search

The effects of commercial logging on tree diversity in tropical rainforest are largely unknown. In this study, selectively logged tropical rainforest in Indo- nesian Borneo is shown to contain high tree species richness, despite severe structural damage. Plots logged 8 years before sampling contained fewer spe- cies of trees greater than 20 centimeters in diameter than did similar-sized unlogged plots.

Charles H. Cannon; David R. Peart; Mark Leighton



Full modeling versus summarizing gene-tree uncertainty: method choice and species-tree accuracy.  


With the proliferation of species-tree methods, empiricists now have to confront the daunting task of method choice. Such decisions might be made based on theoretical considerations alone. However, the messiness of real data means that theoretical ideals may not hold in practice (e.g., with convergence of complicated MCMC algorithms and computational times that limit analyses to small data sets). On the other hand, simplifying assumptions made by some approaches may compromise the accuracy of species-tree estimates. Here we examine the purported tradeoff between accuracy and computational simplicity for species-tree analysis, focusing on the different ways the approaches treat gene-tree uncertainty. By considering a diversity of species trees, as well as different sampling designs and total sampling efforts, we not only compare the accuracy of species-tree estimates across methods, but we also partition the variation in accuracy across factors to identify their relative importance. This analysis shows that although the method of analysis affects accuracy, other factors - namely, the history of species divergence and aspects of the sampling design - have a larger impact. Despite a full modeling of gene tree uncertainty (e.g., using a Bayesian framework), species-tree estimates may not be accurate, particularly for recent diversification histories. Nevertheless, we demonstrate how factors within the control of the empirical investigator (e.g., decisions about sampling) improve the accuracy of species tree estimates, and more so than the method of analysis. Lastly, with much of the attention on species-tree analyses focused on the discord among loci arising from the coalescent, this work also highlights a previously overlooked key determinant of species-tree accuracy for recent divergences - the level of genetic variation at a locus, which has important implications for improving species-tree estimates in practice. PMID:22835380

Knowles, L Lacey; Lanier, Hayley C; Klimov, Pavel B; He, Qixin



Dominance of legume trees alters nutrient relations in mixed species ...  


Nutrient relations of four tree species occurring in both planting mixtures were ... This demonstrate forms of plastic adjustment in all three non-N2-fixing species ... nitrate immobilization and tighter P recycling compared with the diverse mixture.


Multipurpose Spaces  

ERIC Educational Resources Information Center

|The concept of multipurpose spaces in schools is certainly not new. Especially in elementary schools, the combination of cafeteria and auditorium (and sometimes indoor physical activity space as well) is a well-established approach to maximizing the use of school space and a school district's budget. Nonetheless, there continue to be refinements…

Gordon, Douglas



Inferring Species Trees Directly from Biallelic Genetic Markers: Bypassing Gene Trees in a Full Coalescent Analysis  

PubMed Central

The multispecies coalescent provides an elegant theoretical framework for estimating species trees and species demographics from genetic markers. However, practical applications of the multispecies coalescent model are limited by the need to integrate or sample over all gene trees possible for each genetic marker. Here we describe a polynomial-time algorithm that computes the likelihood of a species tree directly from the markers under a finite-sites model of mutation effectively integrating over all possible gene trees. The method applies to independent (unlinked) biallelic markers such as well-spaced single nucleotide polymorphisms, and we have implemented it in SNAPP, a Markov chain Monte Carlo sampler for inferring species trees, divergence dates, and population sizes. We report results from simulation experiments and from an analysis of 1997 amplified fragment length polymorphism loci in 69 individuals sampled from six species of Ourisia (New Zealand native foxglove).

Bryant, David; Bouckaert, Remco; Felsenstein, Joseph; Rosenberg, Noah A.; RoyChoudhury, Arindam



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

Microsoft Academic Search

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

Lourens Poorter; F. J. J. M. Bongers; Frank J. Sterck; Hannsjörg Wöll



Exploring the Taxonomy of Oaks and Related Tree Species  

ERIC Educational Resources Information Center

|A lab in Eastern North America conducted a study to determine the taxonomic relationship between deciduous trees and several species of oaks by calculating the similarity index of all species to be studied. The study enabled students to classify the different species of oaks according to their distinct characteristics.|

McMaster, Robert T.



Micropropagation of Pithecellobium dulce (Roxb.) Benth-a multipurpose leguminous tree and assessment of genetic fidelity of micropropagated plants using molecular markers.  


An efficient and reproducible protocol has been developed for in vitro propagation of Pithecellobium dulce (Roxb.) Benth (a multipurpose leguminous tree) from field grown nodal segments (axillary bud). Shoot bud induction occurred from nodal explants of 15-years-old tree on Murashige and Skoog (MS) basal medium supplemented with 4.4 ?M 6-benzyladenine (BA) and multiplication was achieved on MS medium supplemented with 4.4 ?M BA + 0.73 ?M phenylacetic acid (PAA) i.e. up to 7 shoot buds in the period of 5-6 weeks. Addition of adenine sulphate (AdS) to this medium further enhanced the number of shoot buds up to 10. Proliferating shoot cultures were established by repeatedly subculturing primary culture on fresh medium (MS + 4.4 ?M BA + 0.73 ?M PAA) after every 25 days. In vitro rooting was achieved on MS medium supplemented with 2.46 ?M Indole-3-butyric acid (IBA) + 41.63 ?M activated charcoal (AC). The micropropagated shoots with well developed roots were acclimatized in green house in pots containing sand, soil and manure (1:1:1). Genetic stability of micropropagated clones was evaluated using Random amplified polymorphic DNA (RAPD) and Inter simple sequence repeat (ISSR) markers. The amplification products were monomorphic in micropropagated plants and similar to those of mother plant. No polymorphism was detected revealing the genetic uniformity of micropropagated plants. This is the first report of an efficient protocol for regeneration of P. dulce through organogenesis, which can be used for further genetic transformation and pharmaceutical purposes. PMID:23573054

Goyal, Pooja; Kachhwaha, Sumita; Kothari, S L



Calibrating divergence times on species trees versus gene trees: implications for speciation history of Aphelocoma jays.  


Estimates of the timing of divergence are central to testing the underlying causes of speciation. Relaxed molecular clocks and fossil calibration have improved these estimates; however, these advances are implemented in the context of gene trees, which can overestimate divergence times. Here we couple recent innovations for dating speciation events with the analytical power of species trees, where multilocus data are considered in a coalescent context. Divergence times are estimated in the bird genus Aphelocoma to test whether speciation in these jays coincided with mountain uplift or glacial cycles. Gene trees and species trees show general agreement that diversification began in the Miocene amid mountain uplift. However, dates from the multilocus species tree are more recent, occurring predominately in the Pleistocene, consistent with theory that divergence times can be significantly overestimated with gene-tree based approaches that do not correct for genetic divergence that predates speciation. In addition to coalescent stochasticity, Haldane's rule could account for some differences in timing estimates between mitochondrial DNA and nuclear genes. By incorporating a fossil calibration applied to the species tree, in addition to the process of gene lineage coalescence, the present approach provides a more biologically realistic framework for dating speciation events, and hence for testing the links between diversification and specific biogeographic and geologic events. PMID:20681982

McCormack, John E; Heled, Joseph; Delaney, Kathleen S; Peterson, A Townsend; Knowles, L Lacey



Mapping urban forest tree species using IKONOS imagery: preliminary results  

Microsoft Academic Search

A stepwise masking system with high-resolution IKONOS imagery was developed to identify and map urban forest tree species\\/groups\\u000a in the City of Tampa, Florida, USA. The eight species\\/groups consist of sand live oak (Quercus geminata), laurel oak (Quercus laurifolia), live oak (Quercus virginiana), magnolia (Magnolia grandiflora), pine (species group), palm (species group), camphor (Cinnamomum camphora), and red maple (Acer rubrum).

Ruiliang Pu



Seedling Growth Strategies in Bauhinia Species: Comparing Lianas and Trees  

PubMed Central

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

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



Bayesian Inference of Species Trees from Multilocus Data  

PubMed Central

Until recently, it has been common practice for a phylogenetic analysis to use a single gene sequence from a single individual organism as a proxy for an entire species. With technological advances, it is now becoming more common to collect data sets containing multiple gene loci and multiple individuals per species. These data sets often reveal the need to directly model intraspecies polymorphism and incomplete lineage sorting in phylogenetic estimation procedures. For a single species, coalescent theory is widely used in contemporary population genetics to model intraspecific gene trees. Here, we present a Bayesian Markov chain Monte Carlo method for the multispecies coalescent. Our method coestimates multiple gene trees embedded in a shared species tree along with the effective population size of both extant and ancestral species. The inference is made possible by multilocus data from multiple individuals per species. Using a multiindividual data set and a series of simulations of rapid species radiations, we demonstrate the efficacy of our new method. These simulations give some insight into the behavior of the method as a function of sampled individuals, sampled loci, and sequence length. Finally, we compare our new method to both an existing method (BEST 2.2) with similar goals and the supermatrix (concatenation) method. We demonstrate that both BEST and our method have much better estimation accuracy for species tree topology than concatenation, and our method outperforms BEST in divergence time and population size estimation.

Heled, Joseph; Drummond, Alexei J.



Phylogenomics-Based Reconstruction of Protozoan Species Tree  

PubMed Central

We have developed a semi-automatic methodology to reconstruct the phylogenetic species tree in Protozoa, integrating different phylogenetic algorithms and programs, and demonstrating the utility of a supermatrix approach to construct phylogenomics-based trees using 31 universal orthologs (UO). The species tree obtained was formed by three major clades that were related to three groups of data: i) Species containing at least 80% of UO (25/31) in the concatenated multiple alignment or supermatrix, this clade was called C1, ii) Species containing between 50%–79% (15–24/31) of UO called C2, and iii) Species containing less than 50% (1–14/31) of UO called C3. C1 was composed by only protozoan species, C2 was composed by species related to Protozoa, and C3 was composed by some species of C1 (Protozoa) and C2 (related to Protozoa). Our phylogenomics-based methodology using a supermatrix approach proved to be reliable with protozoan genome data and using at least 25 UO, suggesting that (a) the more UO used the better, (b) using the entire UO sequence or just a conserved block of it for the supermatrix produced similar phylogenomic trees.

Ocana, Kary A.C.S.; Davila, Alberto M.R.



Geographical Range and Local Abundance of Tree Species in China  

PubMed Central

Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1) whether locally abundant species tend to be geographically widespread; 2) whether species are more abundant towards their range-centers; and 3) how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20–25 ha where all individuals ?1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km2, and >90% of 651 species had ranges >105 km2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species’ abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges.

Ren, Haibao; Condit, Richard; Chen, Bin; Mi, Xiangcheng; Cao, Min; Ye, Wanhui; Hao, Zhanqing; Ma, Keping



Geographical range and local abundance of tree species in china.  


Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1) whether locally abundant species tend to be geographically widespread; 2) whether species are more abundant towards their range-centers; and 3) how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20-25 ha where all individuals ?1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km(2), and >90% of 651 species had ranges >10(5) km(2). There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species' abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges. PMID:24130772

Ren, Haibao; Condit, Richard; Chen, Bin; Mi, Xiangcheng; Cao, Min; Ye, Wanhui; Hao, Zhanqing; Ma, Keping



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


The New World swallow genus Tachycineta comprises nine species that collectively have a wide geographic distribution and remarkable variation both within- and among-species in ecologically important traits. Existing phylogenetic hypotheses for Tachycineta are based on mitochondrial DNA sequences, thus they provide estimates of a single gene tree. In this study we sequenced multiple individuals from each species at 16 nuclear intron loci. We used gene concatenated approaches (Bayesian and maximum likelihood) as well as coalescent-based species tree inference to reconstruct phylogenetic relationships of the genus. We examined the concordance and conflict between the nuclear and mitochondrial trees and between concatenated and coalescent-based inferences. Our results provide an alternative phylogenetic hypothesis to the existing mitochondrial DNA estimate of phylogeny. This new hypothesis provides a more accurate framework in which to explore trait evolution and examine the evolution of the mitochondrial genome in this group. PMID:22750631

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



Gas exchange of six tree species from Central Amazonian floodplains  

Microsoft Academic Search

In Central Amazonian floodplain forests, trees are subjected to periodical flood- ing. The gas exchange behaviour of six tree species with different growth strategies was com- pared between the non-flooded and flooded period. Photosynthetic assimilation and quantum yields were 20-50% lower in the flooded period in non-pioneers, and 10-20% lower in pioneers. The photosynthetic activities reported here appear to be



Why abundant tropical tree species are phylogenetically old.  


Neutral models of species diversity predict patterns of abundance for communities in which all individuals are ecologically equivalent. These models were originally developed for Panamanian trees and successfully reproduce observed distributions of abundance. Neutral models also make macroevolutionary predictions that have rarely been evaluated or tested. Here we show that neutral models predict a humped or flat relationship between species age and population size. In contrast, ages and abundances of tree species in the Panamanian Canal watershed are found to be positively correlated, which falsifies the models. Speciation rates vary among phylogenetic lineages and are partially heritable from mother to daughter species. Variable speciation rates in an otherwise neutral model lead to a demographic advantage for species with low speciation rate. This demographic advantage results in a positive correlation between species age and abundance, as found in the Panamanian tropical forest community. PMID:24043767

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



Species richness, endemism, and conservation of American tree ferns (Cyatheales)  

Microsoft Academic Search

Analyses of richness and endemism of Cyatheales (tree ferns) in tropical America were performed and evidence of a diversity\\u000a gradient is presented. For this, the occurrence ranges of 239 species were plotted into a 5° × 5° grid-cell map and then analyzed\\u000a using species richness and endemism indices. Here we show that species richness and endemism are not distributed randomly

Santiago Ramirez-BarahonaIsolda; Isolda Luna-Vega; Daniel Tejero-Díez



The use of tree rings in tropical forest management: Projecting timber yields of four Bolivian tree species  

Microsoft Academic Search

Sustainable management systems for tropical forests require information on tree growth. Generally, growth rates of commercial tropical tree species are derived from repeated measurements in permanent sample plots. Here, we present an alternative method: the use of tree ring analysis. It has some important advantages over plot studies.The aims of this study were (1) to demonstrate how tree ring analysis

Roel J. W. Brienen; Pieter A. Zuidema



DNA barcoding: species delimitation in tree peonies  

Microsoft Academic Search

Delimitations of species are crucial for correct and precise identification of taxa. Unfortunately “species” is more a subjective\\u000a than an objective concept in taxonomic practice due to difficulties in revealing patterns of infra- or inter-specific variations.\\u000a Molecular phylogenetic studies at the population level solve this problem and lay a sound foundation for DNA barcoding. In\\u000a this paper we exemplify the

JinMei Zhang; JianXiu Wang; Tao Xia; ShiLiang Zhou



Boron toxicity characteristics of four northern California endemic tree species  

Microsoft Academic Search

A greenhouse study was undertaken to determine the characteristics of soil B toxicity for four tree species endemic to The Geysers area in northern California: digger pine (Pinus sabiniana Dougl. ex D. Don), California laurel (or, California bay) (Umbellularia californica (Hoo. and Arn. Nutt.)), madrone (Arbutus menziesii Pursh), and bigleaf maple (Acer macrophyllum Pursh). Significant exponential relationships were found between

B. A. Glaubig; F. T. Bingham



Tree Mass Equations for Commons Species of Newfoundland.  

National Technical Information Service (NTIS)

Equations to predict masses of tree components were prepared for seven species common to the island of Newfoundland. Equations that are applicable to regions of the island and to the whole Island are provided. Breast-height diameter and total height were ...

M. B. Lavigne



Fuelwood characteristics of tree species in homegardens of Kerala, India  

Microsoft Academic Search

Indiscriminate use of natural resources in the past has lead to fuelwood shortages in many parts of the tropical world. To surmount this domestic energy crisis, not only degraded sites must be planted with trees having high fuel value potential, but also agroforestry promoted on arable lands. To enable choice of species for such energy plantations\\/agroforests in the humid tropics

A. Shanavas; B. Mohan Kumar



Improvements to a class of distance matrix methods for inferring species trees from gene trees.  


Among the methods currently available for inferring species trees from gene trees, the GLASS method of Mossel and Roch (2010), the Shallowest Divergence (SD) method of Maddison and Knowles (2006), the STEAC method of Liu et al. (2009), and a related method that we call Minimum Average Coalescence (MAC) are computationally efficient and provide branch length estimates. Further, GLASS and STEAC have been shown to be consistent estimators of tree topology under a multispecies coalescent model. However, divergence time estimates obtained with these methods are all systematically biased under the model because the pairwise interspecific gene divergence times on which they rely must be more ancient than the species divergence time. Jewett and Rosenberg (2012) derived an expression for the bias of GLASS and used it to propose an improved method that they termed iGLASS. Here, we derive the biases of SD, STEAC, and MAC, and we propose improved analogues of these methods that we call iSD, iSTEAC, and iMAC. We conduct simulations to compare the performance of these methods with their original counterparts and with GLASS and iGLASS, finding that each of them decreases the bias and mean squared error of pairwise divergence time estimates. The new methods can therefore contribute to improvements in the estimation of species trees from information on gene trees. PMID:22697239

Helmkamp, Laura J; Jewett, Ethan M; Rosenberg, Noah A



Effects of tree species on soil properties in a forest of the northeastern United States  

Microsoft Academic Search

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

F. A. Dijkstra



An Assessment of Canopy Stratification and Tree Species Diversity Following Clearcutting in Central Appalachian Hardwoods  

Microsoft Academic Search

On high quality growing sites in West Virginia, shade intolerant tree species have increased in importance in third-generation forests following clearcutting. We investi- gated the effect of tree species canopy position on the Shannon-Weiner Diversity Index (H'), Pielou's evenness index (0, and species richness (S) using a chronosequence of 13 clearcuts. Two to 26 yr after clearcutting, tree species diversity

Mark Benjamin Brashears; Mary Ann Fajvan; Thomas M. Schuler



Nonasymptotic Species Richness Models and the Insects of British Trees  

PubMed Central

Nonasymptotic models of species diversity are those that do not consider negative feedback between number of species in a biota and the net rate of species addition. These models propose species richness differences to be primarily the product of geologic age differences among biotas. Nonasymptotic explanations are traditional for various diversity difference spectra, including latitudinal diversity gradients and the greater species richness of ancient compared to young lakes. I review new evidence that renders these nonasymptotic explanations doubtful. The only uncontested evidence in favor of nonasymptotic species accumulation is Southwood's correlation between the number of insect species associated with British tree taxa and the number of Quaternary fossil records of these taxa. I show that nonasymptotic explanations of species richness variation are unacceptable for this system also. The variation in insect species richness among these taxa is well accounted for by a species-area relationship. The species richness asymptote is attained within a few hundred years, and the influence of cumulative host taxon abundance (number of fossil records) upon insect species richness is insignificant after the statistical influence of present-day host plant range is removed. I conclude Southwood's correlation to lack causality; it probably derives from a correlation between the number of fossil records of the host taxa and their present range.

Strong, Donald R.



Complementary resource use by tree species in a rain forest tree plantation.  


Mixed-species tree plantations, composed of high-value native rain forest timbers, are potential forestry systems for the subtropics and tropics that can provide ecological and production benefits. Choices of rain forest tree species for mixtures are generally based on the concept that assemblages of fast-growing and light-demanding species are less productive than assemblages of species with different shade tolerances. We examined the hypothesis that mixtures of two fast-growing species compete for resources, while mixtures of shade-tolerant and shade-intolerant species are complementary. Ecophysiological characteristics of young trees were determined and analyzed with a physiology-based canopy model (MAESTRA) to test species interactions. Contrary to predictions, there was evidence for complementary interactions between two fast-growing species with respect to nutrient uptake, nutrient use efficiency, and nutrient cycling. Fast-growing Elaeocarpus angustifolius had maximum demand for soil nutrients in summer, the most efficient internal recycling of N, and low P use efficiency at the leaf and whole-plant level and produced a large amount of nutrient-rich litter. In contrast, fast-growing Grevillea robusta had maximum demand for soil nutrients in spring and highest leaf nutrient use efficiency for N and P and produced low-nutrient litter. Thus, mixtures of fast-growing G. robusta and E. angustifolius or G. robusta and slow-growing, shade-tolerant Castanospermum australe may have similar or even greater productivity than monocultures, as light requirement is just one of several factors affecting performance of mixed-species plantations. We conclude that the knowledge gained here will be useful for designing large-scale experimental mixtures and commercial forestry systems in subtropical Australia and elsewhere. PMID:20666247

Richards, Anna E; Schmidt, Susanne



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

SciTech Connect

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

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



Genetic engineering and lignin biosynthetic regulation in forest tree species  

Microsoft Academic Search

Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve\\u000a genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products.\\u000a Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral\\u000a diseases, the use of pest

Tang Wei; Janet Ogbon; Aquilla McCoy



Conservation of tree seeds from tropical dry-lands  

Microsoft Academic Search

The tropical trees, Azadirachta indica (neem), Lannea microcarpa, Sclerocarya birrea and Khaya senegalensis, are important multipurpose species. Unfortunately, difficult seed storage behaviour limits the utilization of these species in reforestation programs and agroforestry systems. This thesis presents the results of investigations aimed at a better understanding of the seed biology, particularly focussed on the improvement of seed survival after drying

Oblé Neya



Tree species classification from fused active hyperspectral reflectance and LIDAR measurements  

Microsoft Academic Search

A new terrestrial laser system was tested for tree species classification. A dataset consisting of shape parameters of three boreal tree species was collected with Light Detection and Ranging (LIDAR) and integrated with an actively measured reflectance hyperspectra. Tree species were classified using parameters derived from reflectance spectra and point cloud shape distribution. Classification performance was tested with individual, paired,

Eetu Puttonen; Juha Suomalainen; Teemu Hakala; Esa Räikkönen; Harri Kaartinen; Sanna Kaasalainen; Paula Litkey



Population structure and morphology of the frankincense tree Boswellia papyrifera along an altitude gradient in Eritrea  

Microsoft Academic Search

In Eritrea, the frankincense tree Boswellia papyrifera is a multipurpose plant. Human induced factors such as land clearing for agriculture, overgrazing by livestock and overtapping of resin are threatening its distribution. Against this background, a study was carried out to investigate the species current population structure and tree morphology in five Boswellia areas along an altitude gradient (range 800 -

W. Ogbazghi; F. J. J. M. Bongers; A. J. M. Rijkers; M. Wessel



Urban Tree Species Show the Same Hydraulic Response to Vapor Pressure Deficit across Varying Tree Size and Environmental Conditions  

PubMed Central

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

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



Seasonal variations in isoprene emission from tropical deciduous tree species.  


Isoprene is a dominant constituent of the global biogenic volatile organic compounds budget. It plays an important role in regulating the atmospheric trace gas composition including tropospheric ozone concentrations. In this study, monthly measurements of isoprene emission rates were carried out over a 1-year period (December 2002-November 2003) from four Indian deciduous tree species, namely Ficus relegiosa, Ficus infectoria, Pongamia pinnata, and Morus alba, using branch enclosure method. Significantly high monthly variations in isoprene emission rates were observed in all four-plant species. Also, each plant species exhibited pronounced seasonal variation in isoprene emission. Maximum isoprene emissions were observed during summer and minimum during the winter or spring months. PMID:17242968

Singh, Abhai Pratap; Varshney, C K; Singh, U K



Interannual Variation in Stand Transpiration is Dependent Upon Tree Species  

NASA Astrophysics Data System (ADS)

In order to successfully predict transpirational water fluxes from forested watersheds, interannual variability in transpiration must be quantified and understood. In a heterogeneous forested landscape in northern Wisconsin, we quantified stand transpiration across four forest cover types representing more than 80 percent of the land area in order to 1) quantify differences in stand transpiration and leaf area over two years and 2) determine the mechanisms governing the changes in transpiration over two years. We measured sap flux in eight trees of each tree species in the four cover types. We found that in northern hardwoods, the leaf area of sugar maple increased between the two measurement years with transpiration per unit ground area increasing even more than could be explained by leaf area. In an aspen stand, tent caterpillars completely defoliated the stand for approximately a month until a new set of leaves flushed out. The new set of leaves resulted in a lower leaf area but the same transpiration per unit leaf area indicating there was no physiological compensation for the lower leaf area. At the same time, balsam fir growing underneath the aspen increased their transpiration rate in response to greater light penetration through the dominant aspen canopy Red pine had a thirty percent change in leaf area within a growing season due to multiple cohorts of leaves and transpiration followed this leaf area dynamic. In a forested wetland, white cedar transpiration was proportional to surface water depth between the two years. Despite the specific tree species' effects on stand transpiration, all species displayed a minimum water potential regulation resulting in a saturating response of transpiration to vapor pressure deficit that did not vary across the two years. This physiological set point will allow future water flux models to explain mechanistically interannual variability in transpiration of this and similar forests.

Ewers, B. E.; Mackay, D. S.; Burrows, S. N.; Ahl, D. E.; Samanta, S.



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

Microsoft Academic Search

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




Carbon Storage Traits of Main Tree Species in Natural Forests in Northeast China  

Microsoft Academic Search

Carbon storage capacity of tree species is important for sustainable forest management especially in the context of international policy agendas on greenhouse gas emissions mitigation. In this research, the carbon storage traits of main tree species over their life spans in natural forests in Northeast China are studied through allometric relationships between diameter at breast height, tree age, and total

Xiongwen Chen



Resprouting from roots in four Brazilian tree species.  


Previous studies pointed out that species richness and high density values within the Leguminosae in Brazilian forest fragments affected by fire could be due, at least partially, to the high incidence of root sprouting in this family. However, there are few studies of the factors that induce root sprouting in woody plants after disturbance. We investigated the bud formation on root cuttings, and considered a man-made disturbance that isolates the root from the shoot apical dominance of three Leguminosae (Bauhinia forficata Link., Centrolobium tomentosum Guill. ex Benth, and Inga laurina (Sw.) Willd) and one Rutaceae (Esenbeckia febrifuga (St. Hil.) Juss. ex Mart.). All these species resprout frequently after fire. We also attempted to induce bud formation on root systems by removing the main trunk, girdling or sectioning the shallow lateral roots from forest tree species Esenbeckia febrifuga and Hymenaea courbaril L. We identified the origin of shoot primordia and their early development by fixing the samples in Karnovsky solution, dehydrating in ethyl alcohol series and embedding in plastic resin. Serial sections were cut on a rotary microtome and stained with toluidine blue O. Permanent slides were mounted in synthetic resin. We observed different modes of bud origin on root cuttings: close to the vascular cambium (C. tomentosum), from the callus (B. forficata and E. febrifuga) and from the phloematic parenchyma proliferation (I. laurina). Fragments of B. forficata root bark were also capable of forming reparative buds from healing phellogen formed in callus in the bark's inner side. In the attempt of bud induction on root systems, Hymenaea courbaril did not respond to any of the induction tests, probably because of plant age. However, Esenbeckia febrifuga roots formed suckers when the main trunk was removed or their roots were sectioned and isolated from the original plant. We experimentally demonstrated the ability of four tree species to resprout from roots after disturbance. Our results suggest that the release of apical dominance enables root resprouting in the studied species. PMID:19928472

Hayashi, Adriana Hissae; Appezzato-da-Glória, Beatriz



Earthworm Abundance and Species Composition in Abandoned Tropical Croplands: Comparisons of Tree Plantations and Secondary Forests.  

National Technical Information Service (NTIS)

We compared patterns of earthworm abundance and species composition in tree plantations and secondary forests of Puerto Rico. Tree plantations included pine (Pinus carbibaea Morelet) and mahogany (Swietenia macrophylla King) established in the 1930s; 1960...

G. Gonzalez X. Zou S. Borges



Process-based modeling of species' distributions: what limits temperate tree species' range boundaries?  


Niche-based models are widely used to understand what environmental factors determine species' distributions, but they do not provide a clear framework to study the processes involved in defining species' ranges. Here we used a process-based model to identify these processes and to assess the potential distribution of 17 North American boreal/temperate tree species. Using input of only climate and soil properties, the model reproduced the 17 species' distributions accurately. Our results allowed us to identify the climatic factors as well as the biological processes involved in limiting species' ranges. The model showed that climatic constraints limit species' distributions mainly through their impact on phenological processes, and secondarily through their impact on drought and frost mortality. The northern limit of species' ranges appears to be caused mainly by the inability to undergo full fruit ripening and/or flowering, while the southern limit is caused by the inability to flower or by frost injury to flowers. These findings about the ecological processes shaping tree species' distribution represent a crucial step toward obtaining a more complete picture of the potential impact of climate on species' ranges. PMID:17918406

Morin, Xavier; Augspurger, Carol; Chuine, Isabelle



Neogene origins and implied warmth tolerance of Amazon tree species.  


Tropical rain forest has been a persistent feature in South America for at least 55 million years. The future of the contemporary Amazon forest is uncertain, however, as the region is entering conditions with no past analogue, combining rapidly increasing air temperatures, high atmospheric carbon dioxide concentrations, possible extreme droughts, and extensive removal and modification by humans. Given the long-term Cenozoic cooling trend, it is unknown whether Amazon forests can tolerate air temperature increases, with suggestions that lowland forests lack warm-adapted taxa, leading to inevitable species losses. In response to this uncertainty, we posit a simple hypothesis: the older the age of a species prior to the Pleistocene, the warmer the climate it has previously survived, with Pliocene (2.6-5 Ma) and late-Miocene (8-10 Ma) air temperature across Amazonia being similar to 2100 temperature projections under low and high carbon emission scenarios, respectively. Using comparative phylogeographic analyses, we show that 9 of 12 widespread Amazon tree species have Pliocene or earlier lineages (>2.6 Ma), with seven dating from the Miocene (>5.6 Ma) and three >8 Ma. The remarkably old age of these species suggest that Amazon forests passed through warmth similar to 2100 levels and that, in the absence of other major environmental changes, near-term high temperature-induced mass species extinction is unlikely. PMID:23404439

Dick, Christopher W; Lewis, Simon L; Maslin, Mark; Bermingham, Eldredge



The complex biogeographic history of a widespread tropical tree species.  


Many tropical forest tree species have broad geographic ranges, and fossil records indicate that population disjunctions in some species were established millions of years ago. Here we relate biogeographic history to patterns of population differentiation, mutational and demographic processes in the widespread rainforest tree Symphonia globulifera using ribosomal (ITS) and chloroplast DNA sequences and nuclear microsatellite (nSSR) loci. Fossil records document sweepstakes dispersal origins of Neotropical S. globulifera populations from Africa during the Miocene. Despite historical long-distance gene flow, nSSR differentiation across 13 populations from Costa Rica, Panama, Ecuador (east and west of Andes) and French Guiana was pronounced (F(ST)= 0.14, R(ST)= 0.39, P < 0.001) and allele-size mutations contributed significantly (R(ST) > F(ST)) to the divergences between cis- and trans-Andean populations. Both DNA sequence and nSSR data reflect contrasting demographic histories in lower Mesoamerica and Amazonia. Amazon populations show weak phylogeographic structure and deviation from drift-mutation equilibrium indicating recent population expansion. In Mesoamerica, genetic drift was strong and contributed to marked differentiation among populations. The genetic structure of S. globulifera contains fingerprints of drift-dispersal processes and phylogeographic footprints of geological uplifts and sweepstakes dispersal. PMID:18764917

Dick, Christopher W; Heuertz, Myriam



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

Microsoft Academic Search

Modern forest management poses an increasing need for detailed knowledge of forest information at different spatial scales. At the forest level, the information for tree species assemblage is desired whereas at or below the stand level, individual tree related information is preferred. Remote Sensing provides an effective tool to extract the above information at multiple spatial scales in the continuous

Le Wang



Fusion of airborne hyperspectral and LiDAR data for tree species classification in the temperate forest of northeast China  

Microsoft Academic Search

Tree species classification using hyperspectral data has a problem over the cases of different tree species with similar spectral signals, especially in the natural boreal forests which have abundant tree species. In this paper, we assessed the data fusion capacity of airborne hyperspectral and LiDAR for mapping dominant tree species in Liangshui National Nature Reserve, Heilongjiang Province, China. Training samples

Lijuan Liu; Yong Pang; Wenyi Fan; Zengyuan Li; Mingze Li



Selecting framework tree species for restoring seasonally dry tropical forests in northern Thailand based on field performance  

Microsoft Academic Search

Framework tree species are indigenous forest tree species, planted to complement and accelerate natural regeneration of forest ecosystems and encourage biodiversity recovery, on degraded sites. In this paper we test the extent to which 37 native forest tree species might act as framework tree species to accelerate recovery of evergreen, seasonal forest in a degraded upper watershed in Doi Suthep-Pui

Stephen Elliott; Puttipong Navakitbumrung; Cherdsak Kuarak; Sudarat Zangkum; Vilaiwan Anusarnsunthorn; David Blakesley



Inferring Species Trees from Gene Trees: A Phylogenetic Analysis of the Elapidae (Serpentes) Based on the Amino Acid Sequences of Venom Proteins  

Microsoft Academic Search

Toward the goal of recovering the phylogenetic relationships among elapid snakes, we separately found the shortest trees from the amino acid sequences for the venom proteins phospholipase A2and the short neurotoxin, collectively representing 32 species in 16 genera. We then applied a method we term gene tree parsimony for inferring species trees from gene trees that works by finding the

Joseph B. Slowinski; Alec Knight; Alejandro P. Rooney



Illegal logging, landscape structure and the variation of tree species richness across North Andean forest remnants  

Microsoft Academic Search

We explored the influence of a common practice in tropical countries, namely illegal logging for household consumption (ILHC), as well as that of characteristics of habitat structure on the variation of tree species richness across 10 cloud forest remnants of a Colombian Andean landscape. We estimated species richness for total, early and late successional tree species for each forest fragment.

Jorge Aubad; Pedro Aragón; Miguel Á. Olalla-Tárraga; Miguel Á. Rodríguez



Competitive hierarchies of temperate tree species: Interactions between resource availability and white-tailed deer  

Microsoft Academic Search

Rankings of species-specific juvenile tree growth and survivorship define competitive hierarchies that play a central role in forest dynamics and may also vary in response to herbivory. We conducted an experiment to examine species-specific rankings of sapling growth and survival for six common tree species in temperate forests of the northeastern US as a function of both resource availability and

Christopher E. Tripler; Charles D. Canham; Richard S. Inouye; Jaclyn L. Schnurr



The vertical foliage distributions of six understory tree species in a Chamaecyparis obtusa Endl. forest  

Microsoft Academic Search

The relationships between the amounts of foliage and heights of trees were studied for the dominant understory tree species, including three evergreen and three deciduous species, in a secondary forest of Chamaecyparis obtusa Endl. The relationships showed two phases: leaf increasing and stationary phases. In the leaf-increasing phase, the height growth allowed these species to expand the canopy by increasing

I. P. G. Ardhana; Hiroshi Takeda; Michinori Sakimoto; Toshio Tsutsumi



Phenology of tree species in subtropical forests of Manipur in north eastern India  

Microsoft Academic Search

Phenological characteristics of 32 dominant tree species have been studied in forest ecosystems at Kangchup hills, Manipur (24o45' to 24o51' N latitude and 93o48' to 93o55' E longitude). The leaf drop, leaf flushing, flower and fruit development in understorey and overstorey tree species were studied during January 1993 to December 1994. The number of evergreen tree species were greater than



Ecological distribution of homobaric and heterobaric leaves in tree species of Malaysian lowland tropical rainforest.  


Tree species can generally be classified into two groups, heterobaric and homobaric leafed species, according to whether bundle-sheath extensions (BSEs) are found in the leaf (heterobaric leaf) or not (homobaric leaf). In this study, we study whether the leaf type is related to the growth environment and/or life form type, even in a tropical rain forest, where most trees have evergreen leaves that are generally homobaric. Accordingly, we investigated the distribution of leaf morphological differences across different life forms of 250 tree species in 45 families in a tropical rainforest. In total, 151 species (60%) in 36 families had homobaric leaves, and 99 species (40%) in 21 families had heterobaric leaves. We found that the proportion of heterobaric and homobaric leaf species differed clearly across taxonomic groups and life form types, which were divided into five life form types by their mature tree heights (understory, subcanopy, canopy, and emergent species) and as canopy gap species. Most understory (94%) and subcanopy (83%) species such as Annonaceae had homobaric leaves. In contrast, heterobaric leaf trees appeared more frequently in the canopy species (43%), the emergent species (96%) (such as Dipterocarpaceae), and the canopy gap species (62%). Our results suggest that tree species in the tropical rainforest adapt to spatial differences in the environmental conditions experienced at the mature height of each tree species, such as light intensity and vapor pressure difference, by having differing leaf types (heterobaric or homobaric) because these types potentially have different physiological and/or mechanical functions. PMID:21636445

Kenzo, Tanaka; Ichie, Tomoaki; Watanabe, Yoko; Hiromi, Toru



Recruitment in tropical tree species: revealing complex spatial patterns.  


Seed dispersal should leave a signature on the spatial distribution of recruits that can be quantified using sophisticated techniques of spatial pattern analysis. Here we study spatial patterns of five frugivore-dispersed tropical tree species at the Barro Colorado Island forest, Panama, to describe detailed properties of the spatial patterns of recruits and to investigate whether these patterns were produced by temporally consistent mechanisms. Our spatial point pattern analyses detected the existence of surprising spatial structures, such as double-cluster and superposition patterns, and they allowed for a detailed quantification of their properties. The spatial recruitment patterns were composed of two independent components comprising a random component and a component showing a complex spatial pattern with two critical scales of clustering. The analysis allowed an estimation of the relative contribution of scatter dispersal versus clump dispersal in effective seed dispersal for our study species. Additionally, the cluster characteristics were temporally consistent over 25 years and correlated with several species traits. We are just beginning to discover the richness of spatial patterns found at tropical forests, and we are confident that a combination of advanced point pattern analysis with field data will allow for significant advances in establishing the link between spatial patterns and processes. PMID:19691434

Wiegand, Thorsten; Martínez, Isabel; Huth, Andreas



Consistent influence of tree diameter and species on damage in nine eastern North America tornado blowdowns  

Microsoft Academic Search

Are tree damage patterns in natural-forest windthrows predictable? Here, I synthesize published and unpublished findings from nine North American forest sites that were disturbed by tornadoes, to ask how well tree damage patterns might be predicted on the basis of tree diameter and species identity. All sites were sampled by the author and assistants, using generally similar methodology, thereby avoiding

Chris J. Peterson



Tree root characteristics as criteria for species selection and systems design in agroforestry  

Microsoft Academic Search

This literature review presents information about the role of tree root systems for the functioning of agroforestry associations and rotations and attempts to identify root-related criteria for the selection of agroforestry tree species and the design of agroforestry systems. Tree roots are expected to enrich soil with organic matter, feed soil biomass, reduce nutrient leaching, recycle nutrients from the subsoil

G. Schroth




Microsoft Academic Search

In rainforests, trunk size, strength, crown position, and geometry of a tree affect light interception and the likelihood of mechanical failure. Allometric relationships of tree diameter, wood density, and crown architecture vs. height are described for a diverse range of rainforest trees in Brunei, northern Borneo. The understory species follow a geometric model in their diameter- height relationship (slope, b



Safety of Multipurpose Vans.  

National Technical Information Service (NTIS)

Since 1970, the sales of multipurpose vans have increased threefold. Vans are popular because of their versatility; outdoorsmen, small businessmen, service technicians, and the 'weekend vanner' are using vans for personal transportation, business operatio...



Measuring and Modeling Interspecies Competition of Tree Species in Logged Boreal Mixed Forests  

NASA Astrophysics Data System (ADS)

Forest tree species strongly affect biogeochemical cycles, and the differences are especially pronounced between evergreen and deciduous trees. Many boreal forests are mixed stands containing evergreen and deciduous species. The balance of evergreen and deciduous species changes during succession, yet most biogeochemical field studies and process models ignore mixed stands. The objective of the study was to determine the successional trends of tree species for a boreal logging age sequence in northern Manitoba. The experimental design consisted of eight replicate plots in four different-aged stands that originated from clearcut harvests in 1935 (mature), 1971, 1983, 1990. Dominant tree species were trembling aspen (Populus tremuloides), jack pine (Pinus banksiana), and black spruce (Picea mariana). Six trees of each major tree species were harvested and diameter * height growth relationships were determined by analyzing radial growth of stem disks collected every 0.25 m up the stem. Trembling aspen was the dominant tree species in the younger stands (1983, 1990) while jack pine and black spruce were the dominant tree species in the older stands (1971, mature). Annual growth rings of jack pine and trembling aspen decreased with age and annual radial growth of black spruce increased with stand age. The relationship of annual radial growth with stand age for the three species is discussed in relation to canopy architecture and biogeochemical cycles.

Martin, J.; Plaut, J.; Gower, S. T.; Weber, J.



Survival of tree seedlings on different species of decaying wood maintains tree distribution in Michigan hemlock-hardwood forests  

Microsoft Academic Search

Summary 1. Seedlings of some tree species are strongly associated with decaying wood in the germination or establishment period. Despite recognition of this pattern in forests around the world, few studies have compared the ability of different species of decaying wood to support seedlings. 2. We measured the abundance, survival, and age distribution of seedlings of Tsuga canadensis (eastern hemlock),

Laura Marx; Michael B. Walters



EPA Science Inventory

Empirical ecological response surfaces were derived for eight dominant tree species in the boreal forest region of Canada. tepwise logistic regression was used to model species dominance as a response to five climatic predictor variables. he predictor variables (annual snowfall, ...


A dynamic species modeling approach to assess climate change impacts on California tree species  

NASA Astrophysics Data System (ADS)

Global climate change during the 21st century is anticipated to have consequences on potential niche viability for woody plant species. Previous research on modeling bioclimatic envelopes has allowed us to predict where to find species assemblages under future climate scenarios and hence predict loss or gain of specific habitats. However, species may not identically respond to climate change. This could result in species disassembling and disagreement between predicted potential niches and realized niches. Therefore, it is critical to examine potential niche shifts at the species level. We used a spatially explicit demographic model to predict shifts in tree species of the northern Sierra Nevada mountains in the context of competition with neighboring plant functional types as well as disturbance (i.e. fire) under various climate change scenarios. Additionally, we incorporated a dispersal model to account for intermediary dispersal strategies. In particular, we were interested in modeling Pinus species found in the "checkerboard" region of the northern Sierra Nevada. These populations are of novel interest due to their disparate management strategies (private vs. public landownership). Our findings have important implications for the assessment of the impact of climate change on these high elevation Montane species.

Ries, L. P.; Hannah, L.; Thorne, J.; Seo, C.; Davis, F.



Investigating multiple data sources for tree species classification in temperate forest and use for single tree delineation  

NASA Astrophysics Data System (ADS)

Despite numerous studies existing for tree species classification the difficult situation in dense and mixed temperate forest is still a challenging task. This study attempts to extend the existing limitations by investigating comprehensive sets of different types of features derived from multiple data sources. These sets include features from full-waveform LiDAR, LiDAR height metrics, texture, hyperspectral data and colour infrared (CIR) images. Support vector machines (SVM) are used as an appropriate classifier to handle the high dimensional feature space and an internal ranking method allows the determination of the most important parameters. In addition, for species discrimination, focus is put on single tree applicable scale. While most experiences within these scales derive from boreal forests and are often restricted to two or three species, we concentrate on more complex temperate forests. The four main species pine (Pinus sylvestris), spruce (Picea abies), oak (Quercus petraea) and beech (Fagus sylvatica) are classified with an accuracy of 89.7%, 88.7%, 83.1% and 90.7%, respectively. Instead of directly classifying delineated single trees a raster cell based classification is conducted. This overcomes problems with erroneous polygons of merged tree crowns, which occur frequently within dense deciduous or mixed canopies. Lastly, we further test the possibility to correct these failures by combining species classification with single tree delineation.

Heinzel, Johannes; Koch, Barbara



Phenology and recruitment of Caryocar costaricense (Caryocaceae), an endemic tree species of Southern Central America  

Microsoft Academic Search

Basic aspects of the reproductive biology are largely unknown for most tropical tree species, although they are important elements to understand the impacts of anthropogenic activities as logging and forest fragmentation on these populations. In this study, data are presented on leaf and reproductive phenol- ogy, fruit production and seedling demography of a population of an endemic tree species of

Silvia Solís; Jorge Lobo; Mayori Grimaldo



Adaptability of 14 Tree Species to Two Hydrol Humic Latosol Soils in Hawaii.  

National Technical Information Service (NTIS)

Tree species capable of thriving on soils in high rainfall areas are needed in Hawaii for reforestation. The soils are highly leached and infertile. Two native and 12 introduced tree species were planted at two sites to determine adaptability. Survival, g...

C. D. Whitesell M. O. Isherwood



Species-specific effects of a 1994 ice storm on radial tree growth in ...  


However, long-term effects of ice storms on tree growth are largely unknown. ... established seventy-five study plots to sample four species of trees (southern red ... The objective of this study is to identify multi-year species-specific responses to  ...


Ambient Levels of Ozone Reduce Net Photosynthesis in Tree and Crop Species  

Microsoft Academic Search

Experiments were conducted to measure the photosynthetic response of three crop and four tree species to realistic concentrations of ozone and (for tree species only) simulated acidic rain. The ozone concentrations were representative of those found in clean ambient air, in mildly to moderately polluted air such as occurs in much of the United States during the summer, and in

Peter B. Reich; Robert G. Amundson



Population and species differences in treeline tree species germination in response to climate change  

NASA Astrophysics Data System (ADS)

The ability of plant species to recruit within and beyond their current geographic ranges in response to climate warming may be constrained by population differences in response. A number of studies have highlighted the degree to which genotype and environment are strongly linked in forest trees (i.e., provenances), but few studies have examined whether these local adaptations are at all predictive of population or species response to change. We report the results of lab germination experiments using high and low elevation populations of both limber pine (Pinus flexilis) and Engelmann spruce (Picea engelmannii), which are important treeline species in the Rocky Mountains. Seeds collected in 2008 were germinated under two different temperature regimes (ambient and +5°C) and two different moisture regimes, and followed for 17 weeks. For both species and source elevations, warmer temperatures advanced the timing of emergence by up to 20 days, whereas the effects of moisture were less consistent. At harvest, high elevation limber pine had less root and shoot biomass, and a slightly lower root:shoot ratio, under the +5°C treatment, whereas low elevation limber pine seedling mass was not sensitive to temperature. Whether these differences persist under field conditions will be tested in a field experiment now established at Niwot Ridge, CO. The ability to accurately predict tree seedling recruitment and ultimately shifts in treeline position with climate change will improve our ability to model changes in surface albedo, water cycling and carbon cycling, all of which can generate feedbacks to regional and global climate.

Kueppers, L. M.; Faist, A.; Castanha, C.



Tree species richness promotes productivity in temperate forests through strong complementarity between species.  


Understanding the link between biodiversity and ecosystem functioning (BEF) is pivotal in the context of global biodiversity loss. Yet, long-term effects have been explored only weakly, especially for forests, and no clear evidence has been found regarding the underlying mechanisms. We explore the long-term relationship between diversity and productivity using a forest succession model. Extensive simulations show that tree species richness promotes productivity in European temperate forests across a large climatic gradient, mostly through strong complementarity between species. We show that this biodiversity effect emerges because increasing species richness promotes higher diversity in shade tolerance and growth ability, which results in forests responding faster to small-scale mortality events. Our study generalises results from short-term experiments in grasslands to forest ecosystems and demonstrates that competition for light alone induces a positive effect of biodiversity on productivity, thus providing a new angle for explaining BEF relationships. PMID:21955682

Morin, Xavier; Fahse, Lorenz; Scherer-Lorenzen, Michael; Bugmann, Harald



OA01. 33. High-yielding, medicinal and multi-purpose chenopods (Chenopodium species) for multistorey cropping  

PubMed Central

Purpose: In an effort to develop crop ideotypes for multi-storey cropping under the conditions of eastern Uttar Pradesh, India, a few locally well-adapted chenopods (Chenopodium species) were examined for high yields and their compatibility with many other crops. A few genotypes were identified, selected and recommended as a sole crop as well as along with many other crops. The medicinal value of these chenopods in increasing haemoglobin content in anaemic patient was also evaluated. Method: Available chenopods were evaluated for yield and compatibility in a completely randomized design. About 200 grammes of fresh tender shoots were cooked and fed every day to an anaemic patient having his initial haemoglobin content at 5.2 units. Result: These chenopods produced 13125 to 22688 kgs/ha of edible grade biomass as a sole crop as well as in various crop combinations. The average land equivalent ratio for intercropping with Phaseolus vulgaris was 1.20 indicating 20 per cent yield advantage over sole cropping. These plants were also used as mulch, fuel-wood, walking sticks and live standards for pole type rajma and many other climber crops. After nine days feeding to the anaemic patient, the haemoglobin content increased from 5.2 to 10.0 units. Conclusion: High-density sowing/transplanting coupled with frequent uprooting/picking is trapping solar radiation very efficiently right from its early life stage. A concerted research effort would make it a successful industrial crop. These genotypes are high yielding, input responsive and amenable to scaling up for large scale cultivation. These chenopods are also amenable to the spirit of intensification in the sense that they are responding well to transplanting, spacing and canopy management. A temporally staggered sowing/transplanting, frequent picking/harvesting and high input and high density agriculture would generate a large amount of edible grade biomass that could be used as food, medicine, fodder and feed.

Singh, Shri Niwas; Narayan, Shyam; Gaur, Sateesh Chandra



Growth and physiological response of six Australian rainforest tree species to a light gradient  

Microsoft Academic Search

An understanding of growth and photosynthetic potential of subtropical rainforest species to variations in light environment can be useful for determining the sequence of species introductions in rainforest restoration projects and mixed species plantations. We examined the growth and physiology of six Australian subtropical rainforest tree species in a greenhouse consisting of three artificial light environments (10%, 30%, and 60%

Jeffrey Kelly; Shibu Jose; J. Doland Nichols; Mila Bristow



Tree species fine-root demography parallels habitat specialization across a sandhill soil resource gradient  

Microsoft Academic Search

Single species can substantially alter belowground processes in ecosystems via differential root production and death. However, information on species differences in fine- root demography is virtually absent for natural communities. In this field study, we recorded species-specific fine-root (,2 mm in diameter) demography in adults of four tree species (Pinus palustris, Quercus laevis, Q. incana, and Q. margaretta) that are

Javier F. Espeleta; Jason B. West; Lisa A. Donovan



Soil magnetic susceptibility reflects soil moisture regimes and the adaptability of tree species to these regimes  

USGS Publications Warehouse

Flooded, saturated or poorly drained soils are frequently anaerobic, leading to dissolution of the strongly magnetic minerals, magnetite and maghemite, and a corresponding decrease in soil magnetic susceptibility (MS). In this study of five temperate deciduous forests in east-central Illinois, USA, mean surface soil MS was significantly higher adjacent to upland tree species (31 ?? 10-5 SI) than adjacent to floodplain or lowland tree species (17 ?? 10-5 SI), when comparing regional soils with similar parent material of loessal silt. Although the sites differ in average soil MS for each tree species, the relative order of soil MS means for associated tree species at different locations is similar. Lowland tree species, Celtis occidentalis L., Ulmus americana L., Acer saccharinum L., Carya laciniosa (Michx. f.) Loud., and Fraxinus pennsylvanica Marsh. were associated with the lowest measured soil MS mean values overall and at each site. Tree species' flood tolerance rankings increased significantly, as soil MS values declined, the published rankings having significant correlations with soil MS values for the same species groups. The three published classifications of tree species' flood tolerance were significantly correlated with associated soil MS values at all sites, but most strongly at Allerton Park, the site with the widest range of soil drainage classes and MS values. Using soil MS measurements in forests with soil parent material containing similar initial levels of strongly magnetic minerals can provide a simple, rapid and quantitative method to classify soils according to hydric regimes, including dry conditions, and associated plant composition. Soil MS values thus have the capacity to quantify the continuum of hydric tolerances of tree species and guide tree species selection for reforestation. ?? 2007 Elsevier B.V. All rights reserved.

Wang, J. -S.; Grimley, D. A.; Xu, C.; Dawson, J. O.



Lichen diversity and red-listed lichen species relationships with tree species and diameter in wooded meadows  

Microsoft Academic Search

This study provides a unique large dataset of total epiphytic lichen diversity (fruticose, foliose and crustose species) and\\u000a composition on 1,294 trees of 17 tree species in wooded meadows in Sweden and Estonia, the Baltic region. The inventory (25,380\\u000a observations and 246 lichen taxa) clearly illustrated that Ulmus minor, Quercus robur and Fraxinus excelsior contributed most significantly to epiphytic lichen

Göran Thor; Per Johansson; Mari T. Jönsson



Water-use Comparison of the Invasive Tree Species, Melaleuca Quinquenervia, and two Native Tree Species,Taxodium Distichum and Pinus Elliottii, in Southwest Florida  

NASA Astrophysics Data System (ADS)

Melaleuca (Melaleuca quinquenervia), an invasive tree species in southern Florida, is generally thought to have higher transpiration rates than the native vegetation, however little empirical data is available to support this claim. In this study, thermal dissipation probes were used to measure transpiration rates of the three species growing in a hydric ecotone in southwest Florida. Transpiration rates of melaleuca, slash pine (Pinus elliottii), and bald cypress (Taxodium distichum) were compared to assess seasonal variability between the wet and dry seasons. Individually trees of both bald cypress and slash pine showed significantly higher water fluxes than melaleuca (p<0.05). However, when individual tree fluxes were scaled to the ecosystem-level, melaleuca contributed 21% of the water flux and bald cypress contributed 72% during the wet season. Melaleuca's increased contribution at the landscape-level results from higher tree densities at our study site. Following leaf senescence in the early dry season, bald cypress continues to be a significant water user at the landscape level. With higher atmospheric demands for water, bald cypress was the least conservative of the three species with respect to water use, whereas on days with low atmospheric demands for water the three species function similarly. These results do not support the hypothesis that melaleuca uses more water than the native Florida tree species, however, they suggest the density of melaleuca at the landscape-scale is important in our understanding of its role in the hydrologic cycle.

Knight, T. M.; Leisure, R. M.; Everham, E. M.; Bovard, B. D.



Population genetics of the threatened tree daisy Olearia gardneri (Asteraceae), conservation of a critically endangered species  

Microsoft Academic Search

All known populations of the nationally critical tree daisy, Olearia gardneri, were studied using AFLP markers. With fewer than 160 individual plants, Olearia gardneri is the third-rarest tree in New Zealand and a good model with which to study evolutionary process in fragmented endangered\\u000a plants. Genetic variation was at similar levels to other long-lived tree species in New Zealand and

A. Barnaud; G. J. Houliston



Mechanical resistance of different tree species to rockfall in the French Alps  

Microsoft Academic Search

In order to determine the mechanical resistance of several forest tree species to rockfall, an inventory of the type of\\u000a damage sustained in an active rockfall corridor was carried out in the French Alps. The diameter, spatial position\\u000a and type of damage incurred were measured in 423 trees. Only 5% of trees had sustained damage above a height\\u000a of 1.3

Alexia Stokes; Franck Salin; Adzo Dzifa Kokutse; Stéphane Berthier; Henri Jeannin; Shaun Mochan; Luuk Dorren; Nomessi Kokutse; Murad Abd. Ghani; Thierry Fourcaud


Triad Tasks, a Multipurpose Tool to Elicit Similarity Judgments: The Case of Tzotzil Maya Plant Taxonomy  

Microsoft Academic Search

The universality of multipurpose taxonomies has been widely established in folk biology. However, recent studies with nonprofessional fish experts in the United States as well as with tree experts in the Chicago area suggest that different goals can affect category organization of natural kinds. This article reports the results of a triad task study exploring specific aspects of the multipurpose

Norbert Ross; Tomás Barrientos; Alberto Esquit-Choy



Energy Values for Whole Trees and Crowns of Selected Species  

Microsoft Academic Search

Background Energy values, Btu's (British thermal units) per ovendry pound, were determined for whole-tree and crown materials from western hemlock {Tsuga heterophylla (Raf.) Sarg.), coast Douglas-fir {Pseudotsuga menziesii (Mirb.) Franco var. menziesii), and western redcedar (Thuja plicata Donn ex D. Don). Samples were collected from small-diameter stands in northwest Washington where whole-tree harvesting is underway. Samples of crown material representing

James O. Howard


Method for estimating potential tree-grade distributions for northeastern forest species. Forest Service research paper (Final)  

SciTech Connect

The generalized logistic regression was used to distribute trees into four potential tree grades for 20 northeastern species groups. The potential tree grade is defined as the tree grade based on the length and amount of clear cuttings and defects only, disregarding minimum grading diameter. The algorithms described use site index and tree diameter as the predictive variables, allowing the equations to be incorporated into individual-tree growth and yield simulators such as NE-TWIGS.

Yaussy, D.A.



Analysis of deciduous tree species dynamics after a severe ice storm using SORTIE model simulations  

Microsoft Academic Search

Ice storms are frequent natural disturbance events in hardwood forests of eastern Canada and the United States, but their effects on forest dynamics are not well understood. Our objectives were to characterize short- and long-term tree species dynamics after a severe ice storm, and to assess the influence of spatial distribution of trees on these dynamics. SORTIE, a spatially explicit

M. Tremblay; C. Messier; D. J. Marceau



Stem biomass and volume models of selected tropical tree species in West Africa  

Microsoft Academic Search

Estimating tree volume and biomass constitutes an essential part of the forest resources assessment and the evaluation of the climate change mitigation potential of forests through biomass accumulation and carbon sequestration. This research article provides stem volume and biomass equations applicable to five tree species, namely Afzelia africana Sm. (Caesalpiniaceae), Anogeissus leiocarpa (DC.) Guill. and Perr. (Combretaceae), Ceiba pentandra (L.)

GHS Guendehou; A Lehtonen; M Moudachirou; R Mäkipää; B Sinsin




Technology Transfer Automated Retrieval System (TEKTRAN)

Peach (Prunus persica) represents a model species for the Rosaceae, which includes a number of economically important fruit trees. To develop an extensive Prunus EST database for identification and cloning of genes important to fruit and tree development, we generated 9984 high-quality expressed seq...


Multilocus species tree analyses resolve the radiation of the widespread Bufo bufo species group (Anura, Bufonidae).  


New analytical methods are improving our ability to reconstruct robust species trees from multilocus datasets, despite difficulties in phylogenetic reconstruction associated with recent, rapid divergence, incomplete lineage sorting and/or introgression. In this study, we applied these methods to resolve the radiation of toads in the Bufo bufo (Anura, Bufonidae) species group, ranging from the Iberian Peninsula and North Africa to Siberia, based on sequences from two mitochondrial and four nuclear DNA regions (3490 base pairs). We obtained a fully-resolved topology, with the recently described Bufo eichwaldi from the Talysh Mountains in south Azerbaijan and Iran as the sister taxon to a clade including: (1) north African, Iberian, and most French populations, referred herein to Bufo spinosus based on the implied inclusion of populations from its type locality and (2) a second clade, sister to B. spinosus, including two sister subclades: one with all samples of Bufo verrucosissimus from the Caucasus and another one with samples of B. bufo from northern France to Russia, including the Apennine and Balkan peninsulas and most of Anatolia. Coalescent-based estimations of time to most recent common ancestors for each species and selected subclades allowed historical reconstruction of the diversification of the species group in the context of Mediterranean paleogeography and indicated a long evolutionary history in this region. Finally, we used our data to delimit the ranges of the four species, particularly the more widespread and historically confused B. spinosus and B. bufo, and identify potential contact zones, some of which show striking parallels with other co-distributed species. PMID:21964513

Recuero, E; Canestrelli, D; Vörös, J; Szabó, K; Poyarkov, N A; Arntzen, J W; Crnobrnja-Isailovic, J; Kidov, A A; Cog?lniceanu, D; Caputo, F P; Nascetti, G; Martínez-Solano, I



Multipurpose marine Buoy  

Microsoft Academic Search

Solving the meteorological and oceanographic monitoring problems in frame of the actual ldquoJadran Projectrdquo the multipurpose marine buoy was developed to meat specific requirements in Adriatic Sea. The aluminum plastic coated buoy was designed to ensure stabile behavior at any waves high and wind speed that can occur in Adriatic aquatory. The 3 m high upper platform is provided for

Tomislav Tomiša; Slavko Krajcar; D. Pinezic



Multipurpose Visualization System  

Microsoft Academic Search

This paper deals with the design and architecture of the low cost multipurpose flight visualization system (MFVS). The MFVS system was originally developed as a passive IFR approach system for general aviation small planes. A relatively high adaptability is one of the main advantages. It can be easily used with many types of avionics devices. The GPS\\/INS system is used

P. Bojda; P. Frantis



Multipurpose Reprocessing Hot Cell.  

National Technical Information Service (NTIS)

A multipurpose hot cell for use in the new head end system is described. The use of a hot cell as part of the routine fuel charging procedure provides considerable flexibility in handling a wide variety of fuel sizes up to 25,000 lb.

R. D. Fletcher



Leapfrogging of tree species provenances? Interaction of microclimate and genetics on upward shifts in tree species' range limits  

NASA Astrophysics Data System (ADS)

The elevation limit of tree growth (alpine treeline) is considered to be constrained by environmental (i.e., thermal) and genetic (i.e., inability to adapt to climatic conditions) limitations to growth. Warming conditions due to climate change are predicted to cause upward shifts in the elevation of alpine treelines, through relief of cold-induced physiological limitations on seedling recruitment beyond current treeline boundaries. To determine how genetics and climate may interact to affect seedling establishment, we transplanted recently germinated seedlings from high- and low-elevation provenances (HI and LO, respectively) of Pinus flexilis in common gardens arrayed along an elevation and canopy gradient from subalpine forest into the alpine zone at Niwot Ridge, CO. We compared differences in microclimate and seedling ecophysiology among sites and between provenances. During the first summer of growth, frequently cloudy skies resulted in similar solar radiation incidence and air and soil temperatures among sites, despite nearly a 500 m-span in elevation across all sites. Preliminary findings suggest that survival of seedlings was similar between the lowest and highest elevations, with greater survival of LO (60%) compared to HI (40%) seedlings at each of these sites. Photosynthesis, carbon balance (photosynthesis/respiration), and conductance increased more than 2X with elevation for both provenances, and were 35-77% greater in LO seedlings compared to HI seedlings. There were no differences in dark-adapted chlorophyll fluorescence (Fv/Fm) among sites or between provenances. However, in a common-garden study at low elevation, we observed no differences in carbon or water relations between two naturally-germinated mitochondrial haplotypes of P. flexilis (of narrow and wide-ranging distributions). We did observe water-related thresholds on seedling carbon balance and survival that occurred when soil volumetric water content dropped below 10% and seedling water potentials went below -4 MPa. Our preliminary results suggest that for high-elevation conifer seedlings such as P. flexilis: 1) individuals can survive and even have enhanced physiological performance at and above treeline when/where clouds or other conditions minimize factors like cold-induced photoinhibition; 2) in the field, provenances selected for aboveground growth may out-perform those selected for stress-resistance in the absence of harsh climatic conditions, even well above the species' range limits in the alpine; 3) water, and not thermal, limitations might explain treeline altitude in this particular mountain range; 4) forest genetics may be important to understanding and managing species' range adjustments due to climate change.

Reinhardt, K.; Castanha, C.; Germino, M. J.; Kueppers, L. M.



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


P.O. Box 96090 ... Hutton's Vireos, American Robins, and Black-headed Grosbeaks showed a preference for ... For recruitment to mature trees, these shade-intolerant species need openings in the understory that were probably created ...


Reproductive phenology of Atlantic forest tree species in Brazil: an eleven year study  

Microsoft Academic Search

This paper describes the reproductive phenorhythms of tree species in a tropical seasonal lowland forest in Southeastern Brazil. Every two weeks, five individuals of 41 species were observed for the occurrence of flowering and fruiting, from May 1982 to December 1992. All phenophases showed high seasonality, when considering the whole set of species, but the amplitude of the cycles was



Variation in quality parameters between and within 14 Nordic tree fruit and berry species  

Microsoft Academic Search

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient

Grete Skrede; Berit Karoline Martinsen; Anne-Berit Wold; Stein-Erik Birkeland; Kjersti Aaby



Variation in quality parameters between and within 14 Nordic tree fruit and berry species  

Microsoft Academic Search

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient

Grete Skrede; Berit Karoline Martinsen; Anne-Berit Wold; Stein-Erik Birkeland; Kjersti Aaby



Comparison of methods for species-tree inference in the sawfly genus Neodiprion (Hymenoptera: Diprionidae).  


Conifer-feeding sawflies in the genus Neodiprion provide an excellent opportunity to investigate the origin and maintenance of barriers to reproduction, but obtaining a phylogenetic estimate for comparative studies of Neodiprion speciation has proved difficult. Specifically, nonmonophyly within and discordance between individual gene trees, both of which are common in groups that diverged recently and/or rapidly, make it impossible to infer a species tree using methods that are designed to estimate gene trees. Therefore, in this study, we estimate relationships between members of the lecontei species group using four approaches that are intended to estimate species, not gene, trees: (1) minimize deep coalescences (MDC), (2) shallowest divergences (SD), (3) Bayesian estimation of species trees (BEST), and (4) a novel approach that combines concatenation with monophyly constraints (CMC). Multiple populations are sampled for most species and all four methods incorporate this intraspecific variation into estimates of interspecific relationships. We investigate the sensitivity of each method to taxonomic sampling, and, for the BEST method, we assess the impact of prior choice on species-tree inference. We also compare species-tree estimates to one another and to a morphologically based hypothesis to identify clades that are supported by multiple analyses and lines of evidence. We find that both taxonomic sampling and method choice impact species-tree estimates and that, for these data, the BEST method is strongly influenced by Theta and branch-length priors. We also find that the CMC method is the least sensitive to taxonomic sampling. Finally, although interspecific genetic variation is low due to the recent divergence of the lecontei group, our results to date suggest that incomplete lineage sorting and interspecific gene flow are the main factors complicating species-tree inference in Neodiprion. Based on these analyses, we propose a phylogenetic hypothesis for the lecontei group. Finally, our results suggest that, even for very challenging groups like Neodiprion, an underlying species-tree signal can be extracted from multi-locus data as long as intraspecific variation is adequately sampled and methods that focus on the estimation of species trees are used. PMID:19085330

Linnen, Catherine R; Farrell, Brian D



Conservation prospects for threatened Vietnamese tree species: results from a demographic study  

Microsoft Academic Search

Given that changes in population size are slow, information on future prospects of long-lived tree species is necessarily\\u000a obtained from demographic models. We studied six threatened tree species in four Vietnamese protected areas: the broad-leaved\\u000a Annamocarya sinensis, Manglietia fordiana and Parashorea chinensis, and the coniferous Calocedrus macrolepis, Dacrydium elatum and Pinus kwangtungensis. With data from a 2-year field study on

Pham Duc Chien; Pieter A. Zuidema; Nguyen Hoang Nghia



Tree species impact the terrestrial cycle of silicon through various uptakes  

Microsoft Academic Search

The quantification of silicon (Si) uptake by tree species is a mandatory step to study the role of forest vegetations in the\\u000a global cycle of Si. Forest tree species can impact the hydrological output of dissolved Si (DSi) through root induced weathering\\u000a of silicates but also through Si uptake and restitution via litterfall. Here, monospecific stands of Douglas fir, Norway

J.-T. Cornelis; J. Ranger; A. Iserentant; B. Delvaux



Calcium weathering in forested soils and the effect of different tree species  

Microsoft Academic Search

Soil weathering can be an important mechanism to neutralize acidity inforest soils. Tree species may differ in their effect on or response to soilweathering. We used soil mineral data and the natural strontium isotope ratio87Sr\\/86Sr as a tracer to identify the effect of treespecies on the Ca weathering rate. The tree species studied were sugar maple(Acer saccharum), hemlock (TsugaCanadensis), American

Feike A. Dijkstra; Nico Van Breemen; Antoine G. Jongmans; Gareth R. Davies; Gene E. Likens



Soil-atmosphere exchange of greenhouse gases in subtropical plantations of indigenous tree species  

Microsoft Academic Search

Indigenous broadleaf plantations are increasingly developing as a prospective silvicultural management approach for substituting\\u000a in place of large pure conifer plantations in subtropical China. However, little information is known about the effects of\\u000a tree species conversion on soil-atmosphere greenhouse gas (GHG) exchanges. Four adjacent monospecific plantations were selected\\u000a in subtropical China to examine the effects of tree species on soil-atmosphere

Hui Wang; Shirong Liu; Jiangming Mo; Tao Zhang



Supercooling Capacity Increases from Sea Level to Tree Line in the Hawaiian Tree Species Metrosideros polymorpha.  


Population-specific differences in the freezing resistance of Metrosideros polymorpha leaves were studied along an elevational gradient from sea level to tree line (located at ca. 2500 m above sea level) on the east flank of the Mauna Loa volcano in Hawaii. In addition, we also studied 8-yr-old saplings grown in a common garden from seeds collected from the same field populations. Leaves of low-elevation field plants exhibited damage at -2 degrees C, before the onset of ice formation, which occurred at -5.7 degrees C. Leaves of high-elevation plants exhibited damage at ca. -8.5 degrees C, concurrent with ice formation in the leaf tissue, which is typical of plants that avoid freezing in their natural environment by supercooling. Nuclear magnetic resonance studies revealed that water molecules of both extra- and intracellular leaf water fractions from high-elevation plants had restricted mobility, which is consistent with their low water content and their high levels of osmotically active solutes. Decreased mobility of water molecules may delay ice nucleation and/or ice growth and may therefore enhance the ability of plant tissues to supercool. Leaf traits that correlated with specific differences in supercooling capacity were in part genetically determined and in part environmentally induced. Evidence indicated that lower apoplastic water content and smaller intercellular spaces were associated with the larger supercooling capacity of the plant's foliage at tree line. The irreversible tissue-damage temperature decreased by ca. 7 degrees C from sea level to tree line in leaves of field populations. However, this decrease appears to be only large enough to allow M. polymorpha trees to avoid leaf tissue damage from freezing up to a level of ca. 2500 m elevation, which is also the current tree line location on the east flank of Mauna Loa. The limited freezing resistance of M. polymorpha leaves may be partially responsible for the occurrence of tree line at a relatively low elevation in Hawaii compared with continental tree lines, which can be up to 1500 m higher. If the elevation of tree line is influenced by the inability of M. polymorpha leaves to supercool to lower subzero temperatures, then it will be the first example that freezing damage resulting from limited supercooling capacity can be a factor in tree line formation. PMID:10817972

Melcher; Cordell; Jones; Scowcroft; Niemczura; Giambelluca; Goldstein



Features of elementary shoot systems of some temperate tree species  

Microsoft Academic Search

Modern concepts of the tree crown structure are based on hierarchic relations of its constitutive elements (Halle, Oldeman, Tomlinson, 1978; Edelin, 1984, 1991; Godin, 2000). Studying for 20 years the crown systems of broad-leaved wood plants of the temperate zone in the natural communities of the European and Far-East parts of Russia, we aimed to describe peculiarities of distinctive young

Irina Sergeevna Antonov; Oxana Valerievna Azov


Effects of urban tree management and species selection on ...  


Author: Nowak, David J.; Stevens, Jack C.; Sisinni, Susan M.; Luley, Christopher J. ... amounts based on such factors as tree size at maturity, life span, and growth rate. ... This article was written and prepared by U.S. Government employees on ...


Relationships among environmental variables and distribution of tree species at high elevation in the Olympic Mountains  

USGS Publications Warehouse

Relationships among environmental variables and occurrence of tree species were investigated at Hurricane Ridge in Olympic National Park, Washington, USA. A transect consisting of three plots was established down one north-and one south-facing slope in stands representing the typical elevational sequence of tree species. Tree species included subalpine fir (Abies lasiocarpa), Douglas-fir (Pseudotsuga menziesii), mountain hemlock (Tsuga mertensiana), and Pacific silver fir (Abies amabilis). Air and soil temperature, precipitation, and soil moisture were measured during three growing seasons. Snowmelt patterns, soil carbon and moisture release curves were also determined. The plots represented a wide range in soil water potential, a major determinant of tree species distribution (range of minimum values = -1.1 to -8.0 MPa for Pacific silver fir and Douglas-fir plots, respectively). Precipitation intercepted at plots depended on topographic location, storm direction and storm type. Differences in soil moisture among plots was related to soil properties, while annual differences at each plot were most often related to early season precipitation. Changes in climate due to a doubling of atmospheric CO2 will likely shift tree species distributions within, but not among aspects. Change will be buffered by innate tolerance of adult trees and the inertia of soil properties.

Woodward, Andrea



Visible and microscopic injury in leaves of five deciduous tree species related to current critical ozone levels  

Microsoft Academic Search

Because the current critical level of ozone (O3) for forest trees is based only on one species, the responses of five deciduous tree species were differentiated in a climate chamber experiment. The number of symptomatic leaves per tree was significantly increased, and stomatal conductance was decreased under 50% ambient+30 nl l?1 O3 as compared to ‘normal’ senescence at 50% ambient

M. S. Günthardt-Goerg; C. J. McQuattie; S. Maurer; B. Frey




Microsoft Academic Search

The performance of six native forest tree species, planted to restore forest in a degraded watershed in Doi Suthep-Pui National Park, Thailand and their responses to four fertiliser treatments are reported. The species were chosen for their potential to i) shade out competing weeds rapidly and ii) enhance tree species richness by attracting seed-dispersing wildlife. All species planted, except Gmelina

Stephen Elliott; Puttipong Navakitbumrung; Sudarat Zangkum; Cherdsak Kuarak; Janice Kerby; David Blakesley; Vilaiwan Anusarnsunthorn


Identification, measurement and interpretation of tree rings in woody species from mediterranean climates.  


We review the literature dealing with mediterranean climate, vegetation, phenology and ecophysiology relevant to the understanding of tree-ring formation in mediterranean regions. Tree rings have been used extensively in temperate regions to reconstruct responses of forests to past environmental changes. In mediterranean regions, studies of tree rings are scarce, despite their potential for understanding and predicting the effects of global change on important ecological processes such as desertification. In mediterranean regions, due to the great spatio-temporal variability of mediterranean environmental conditions, tree rings are sometimes not formed. Often, clear seasonality is lacking, and vegetation activity is not always associated with regular dormancy periods. We present examples of tree-ring morphology of five species (Arbutus unedo, Fraxinus ornus, Quercus cerris, Q. ilex, Q. pubescens) sampled in Tuscany, Italy, focusing on the difficulties we encountered during the dating. We present an interpretation of anomalies found in the wood structure and, more generally, of cambial activity in such environments. Furthermore, we propose a classification of tree-ring formation in mediterranean environments. Mediterranean tree rings can be dated and used for dendrochronological purposes, but great care should be taken in selecting sampling sites, species and sample trees. PMID:12620063

Cherubini, Paolo; Gartner, Barbara L; Tognetti, Roberto; Bräker, Otto U; Schoch, Werner; Innes, John L



Crown light environments of saplings of two species of rain forest emergent trees  

Microsoft Academic Search

The crown light environments of saplings of two Costa Rican rain forest tree species were simultaneously compared. The species, Dipteryx panamensis (Pitt.) Record & Mell., a relatively shade-intolerant species, and Lecythis ampla Miers, a shade-tolerant species, have contrasting growth and branching patterns. Quantum sensors were placed throughout the crowns of saplings up to 2.5 m tall and quantum fluxes were

S. F. Oberbauer; D. B. Clark; M. Quesada



Tree Species Effects on Soil Organic Matter Dynamics: The Role of Soil Cation Composition  

Microsoft Academic Search

We studied the influence of tree species on soil carbon and nitrogen (N) dynamics in a common garden of replicated monocultures\\u000a of fourteen angiosperm and gymnosperm, broadleaf and needleleaf species in southwestern Poland. We hypothesized that species\\u000a would influence soil organic matter (SOM) decomposition primarily via effects on biogeochemical recalcitrance, with species\\u000a having tissues with high lignin concentrations retarding rates

Sarah E. Hobbie; Megan Ogdahl; Jon Chorover; Oliver A. Chadwick; Jacek Oleksyn; Roma Zytkowiak; Peter B. Reich



Photosynthesis-nitrogen relations in Amazonian tree species  

Microsoft Academic Search

Among species, photosynthetic capacity (Amax) is usually related to leaf nitrogen content (N), but variation in the species-specific relationship is not well understood. To address this issue, we studied Amax-N relationships in 23 species in adjacent Amazonian communities differentially limited by nitrogen (N), phosphorus (P), and\\/or other mineral nutrients. Five species were studied in each of three late successional forest

P. B. Reich; M. B. Walters; D. S. Ellsworth; C. Uhl



The interface between phylogenetics and population genetics: investigating gene trees, species trees, and population dynamics in the Phyllophaga fraterna species group.  


This study uses traditional and contemporary phylogenetic and population genetic analyses to assess the causes of discordance (i.e., lineage sorting and introgression) among mitochondrial and nuclear gene trees for a clade of eastern North American scarab beetles (fraterna species group, genus Phyllophaga). I estimated gene trees using individual and combined analysis of one mitochondrial and two nuclear loci in MrBayes, and inferred a species tree using a hierarchical coalescent approach based on all loci in the program Best. Because hybridization violates the assumptions of BEST, I tested for introgression by comparing species monophyly between the mitochondrial and nuclear gene trees based on the prediction that cytoplasmic genomes introgress more readily than nuclear genomes. Haplotype exclusivity was identified using Bayesian tests of monophyly and the genealogical sorting index. I used the results of the phylogenetic analyses and monophyly tests to develop an explicit hypothesis of introgression that could be tested in the program IMa. Results from these analyses provided evidence for introgression across clades within the fraterna group. The tiered analytical approach used in this study demonstrated how the use of multiple methods can identify when assumptions are violated and methods are prone to yield misleading results. PMID:19895558

Polihronakis, Maxi



Climate warming and precipitation redistribution modify tree-grass interactions and tree species establishment in a warm-temperate savanna.  


Savanna tree-grass interactions may be particularly sensitive to climate change. Establishment of two tree canopy dominants, post oak (Quercus stellata) and eastern redcedar (Juniperus virginiana), grown with the dominant C4 perennial grass (Schizachyrium scoparium) in southern oak savanna of the United States were evaluated under four climatic scenarios for 6 years. Tree-grass interactions were examined with and without warming (+1.5 °C) in combination with a long-term mean rainfall treatment and a modified rainfall regime that redistributed 40% of summer rainfall to spring and fall, intensifying summer drought. The aim was to determine: (1) the relative growth response of these species, (2) potential shifts in the balance of tree-grass interactions, and (3) the trajectory of juniper encroachment into savannas, under these anticipated climatic conditions. Precipitation redistribution reduced relative growth rate (RGR) of trees grown with grass. Warming increased growth of J. virginiana and strongly reduced Q. stellata survival. Tiller numbers of S. scoparium plants were unaffected by warming, but the number of reproductive tillers was increasingly suppressed by intensified drought each year. Growth rates of J. virginiana and Q. stellata were suppressed by grass presence early, but in subsequent years were higher when grown with grass. Quercus stellata had overall reduced RGR, but enhanced survival when grown with grass, while survival of J. virginiana remained near 100% in all treatments. Once trees surpassed a threshold height of 1.1 m, both tiller number and survival of S. scoparium plants were drastically reduced by the presence of J. virginiana, but not Q. stellata. Juniperus virginiana was the only savanna dominant in which neither survival nor final aboveground mass were adversely affected by the climate scenario of warming and intensified summer drought. These responses indicate that climate warming and altered precipitation patterns will further accelerate juniper encroachment and woody thickening in a warm-temperate oak savanna. PMID:23504841

Volder, Astrid; Briske, David D; Tjoelker, Mark G



Effects of missing data on species tree estimation under the coalescent.  


With recent advances in genomic sequencing, the importance of taking the effects of the processes that can cause discord between the speciation history and the individual gene histories into account has become evident. For multilocus datasets, it is difficult toachieve complete coverage of all sampled loci across all sample specimens, a problem that also arises when combining incompletely overlapping datasets. Here we examine how missing data affects the accuracy of species tree reconstruction. In our study, 10- and 100-locus sequence datasets were simulated under the coalescent model from shallow and deep speciation histories, and species trees were estimated using the maximum likelihood and Bayesian frameworks (with STEM and (*)BEAST, respectively). The accuracy of the estimated species trees was evaluated using the symmetric difference and the SPR distance. We examine the effects of sampling more than one individual per species, as well as the effects of different patterns of missing data (i.e., different amounts of missing data, which is represented among random taxa as opposed to being concentrated in specific taxa, as is often the case for empirical studies). Our general conclusion is that the species tree estimates are remarkably resilient to the effects of missing data. We find that for datasets with more limited numbers of loci, sampling more than one individual per species has the strongest effect on improving species tree accuracy when there is missing data, especially at higher degrees of missing data. For larger multilocus datasets (e.g., 25-100loci), the amount of missing data has a negligible effect on species tree reconstruction, even at 50% missing data and a single sampled individual per species. PMID:23769751

Hovmöller, Rasmus; Lacey Knowles, L; Kubatko, Laura S



Population structure, physiology and ecohydrological impacts of dioecious riparian tree species of western North America.  


The global water cycle is intimately linked to vegetation structure and function. Nowhere is this more apparent than in the arid west where riparian forests serve as ribbons of productivity in otherwise mostly unproductive landscapes. Dioecy is common among tree species that make up western North American riparian forests. There are intrinsic physiological differences between male and female dioecious riparian trees that may influence population structure (i.e., the ratio of male to female trees) and impact ecohydrology at large scales. In this paper, we review the current literature on sex ratio patterns and physiology of dioecious riparian tree species. Then develop a conceptual framework of the mechanisms that underlie population structure of dominant riparian tree species. Finally, we identify linkages between population structure and ecohydrological processes such as evapotranspiration and streamflow. A more thorough understanding of the mechanisms that underlie population structure of dominant riparian tree species will enable us to better predict global change impacts on vegetation and water cycling at multiple scales. PMID:17665219

Hultine, K R; Bush, S E; West, A G; Ehleringer, J R



Stem radial growth of different tree species in an unmanaged southern taiga stand  

NASA Astrophysics Data System (ADS)

Radial growth of stems was measured in altogether 32 sample trees of 5 species (Picea abies (L.)Karst., Populus tremula L., Betula alba L., Sorbus aucuparia L. and Alnus incana (L.) Moench) during the growing season 2000 in a mixed uneven-aged stand dominated by spruce and aspen in the region of upper Volga within the framework of international project “Volgaforest”. Measurement was done by band dendrometers read every two weeks from May to late October 2000. In addition, two readings were done in 2001 (the last one in November, i.e. only the total seasonal growth for this year was obtained). Subsequently the woody cores were taken from all sample spruce and aspen trees in October 2002 in order to evaluate the stem growth over a longer period of time. The growing season 2000 was characterized by late spring frost (approximately until May 20) and very wet summer. In contrast the season 2001 was hot and dry. Radial growth of stems in majority of sample trees of all species started during early May and continued until mid August. However the smallest spruce trees and some deciduous trees (especially birches) started growing later (in late May or even in mid June) and the relatively small aspen trees (although reaching DBH up to 33 cm) did not grew at all during the whole season. As an exception, growth of 2 sample trees (spruce and aspen) continued during the whole season up to mid October. The most interesting seems that aspen showed significantly lower growth of basal area in absolute and relative terms when compared to spruce. This difference was observed in both years under consideration, but was more pronounced in 2000, when the relative growth of basal area reached 1 to 6% in spruce, and was increasing with tree DBH, whereas for aspens the same parameter ranged from 0% for smaller trees to 0.8% for the largest ones. Such difference was not so pronounced and occurred only in small and medium DBH trees in the more favorable growing season of 2001. However, radial growth of the largest aspen tree was similar as in spruce trees with comparable DBH. The reduced growth of aspens can be explained by different factors including normal decrease of growth for the given, rather old age for the species (about 60 years) and the specific conditions of the season 2000 (especially strong spring frost). This result well corresponds with the observed succession changes. Massive occurrence of stem rot and following windfall of aspen trees was manifested. No young aspen trees occurred in the stand, whereas gradual prevailing of regenerated spruce was evident.

Tatarinov, F.; Nadezhdina, N.; Bochkarev, Yu.; Cermak, J.



Fodder shrub and tree species in the Highlands of southern Mexico  

Microsoft Academic Search

The purpose of this investigation was to recognize, to select and to evaluate shrub and tree species with forage potential as a way to promote their systematic use as food for sheep. This research took place in five indigenous communities of Chiapas, Mexico. By means of interviews with producers, a list of 37 species was obtained, of which 14 were

J. Nahed; L. Villafuerte; D. Grande; F. Pérez-Gil; T. Alemán; J. Carmona



Feature selection for tree species identification in very high resolution satellite images  

Microsoft Academic Search

The aim of this study was to provide an effective feature selection for tree species classifiers in mixed-species boreal forest, from a very high resolution optical satellite image. The 35 input features were the 5 input spectral bands (multispectral and panchromatic channels), 9 contextual features derived from the panchromatic channel and 21 segment-wise features computed at three segment sizes around

Matthieu Molinier; Heikki Astola



Ecological response surfaces for North American boreal tree species and their use in forest classification  

Microsoft Academic Search

Empirical ecological response surfaces were derived for eight dominant tree species in the boreal forest region of Canada. Stepwise logistic regression was used to model species dominance as a response to five climatic predictor variables. The predictor variables (annual snowfall, degree-days, absolute minimum temperature, annual soil moisture deficit, and actual evapotranspiration summed over the summer months) influence the response of

James M. Lenihan



Effect of tree species and soil properties on nutrient immobilization in the forest floor  

Microsoft Academic Search

To investigate the effect of tree species and soil properties on organic matter accumulation and associated nutrients, an area-based sampling of the forest floor was carried out in a 28 years old species trial including Norway spruce, Douglas fir, beech, and common oak at two sites, a poor and sandy soil, and a fertile loamy soil.

Karsten Raulund-Rasmussen; Henrik Vejre



Spatial Distribution and Interspecific Associations of Tree Species in a Tropical Seasonal Rain Forest of China  

PubMed Central

Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1) fourteen of the twenty tree species were negatively (or positively) associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2) Most saplings of the study species showed a significantly clumped distribution at small scales (0–10 m) which was lost at larger scales (10–30 m). (3) The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4) It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely) contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China.

Lan, Guoyu; Getzin, Stephan; Wiegand, Thorsten; Hu, Yuehua; Xie, Guishui; Zhu, Hua; Cao, Min



Firewood crops. Shrub and tree species for energy production  

SciTech Connect

The report of an ad hoc panel of the Advisory Committee on Technology Innovation Board on Science and Technology for International Development Commission on International Relations. After an introduction by Eckholm, E., the first chapter, Wood as fuel, discusses firewood plantations, fuelwood management and species, wood-burning stoves, and the use of charcoal. The remaining 3 chapters each describe in alphabetical order: fuelwood species for humid tropics, tropical highlands, and for arid and semiarid regions. For each species there is a general description and data on distribution, use as firewood, yield, other uses, environmental requirements, establishment, pests and diseases, and limitations, with at least one black and white plate. There are 10 appendices: Using fuelwood efficiently; Case study; Ethiopia; Cast study: South Korea (Eckholm, E.); Master list of firewood species; Selected readings (general, and by species); Research contacts (by species); Explanation of terms; Biographical sketches of panel members; Contributors (to the report); and Index of plants.

Ruskin, F.R.



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


Several fast-growing and multipurpose tree species have been widely used in West Africa to both reverse the tendency of land degradation and restore soil productivity. Although beneficial effects have been reported on soil stabilization, there still remains a lack of information about their impact on soil microorganisms. Our investigation has been carried out in exotic and native tree plantations of 28 years and aimed to survey and compare the abundance and genetic diversity of natural legume-nodulating rhizobia (LNR). The study of LNR is supported by the phylogenetic analysis which clustered the isolates into three genera: Bradyrhizobium, Mesorhizobium, and Sinorhizobium. The results showed close positive correlations between the sizes of LNR populations estimated both in the dry and rainy seasons and the presence of legume tree hosts. There were significant increases in Rhizobium spp. population densities in response to planting with Acacia spp., and high genetic diversities and richness of genotypes were fittest in these tree plantations. This suggests that enrichment of soil Rhizobium spp. populations is host specific. The results indicated also that species of genera Mesorhizobium and Sinorhizobium were lacking in plantations of non-host species. By contrast, there was a widespread distribution of Bradyrhizobium spp. strains across the tree plantations, with no evident specialization in regard to plantation type. Finally, the study provides information about the LNR communities associated with a range of old tree plantations and some aspects of their relationships to soil factors, which may facilitate the management of man-made forest systems that target ecosystem rehabilitation and preservation of soil biota. PMID:22864803

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



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


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

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



Supplemental planting of early successional tree species during bottomland hardwood afforestation  

USGS Publications Warehouse

Reforestation of former bottom land hardwood forests that have been cleared for agriculture (i.e., afforestation) has historically emphasized planting heavy-seeded oaks (Quercus spp.) and pecans (Carya spp.). These species are slow to develop vertical forest structure. However, vertical forest structure is key to colonization of afforested sites by forest birds. Although early-successional tree species often enhance vertical structure, few of these species invade afforested sites that are distant from seed sources. Furthermore, many land mangers are reluctant to establish and maintain stands of fast-growing plantation trees. Therefore, on 40 afforested bottomland sites, we supplemented heavy-seeded seedlings with 8 patches of fast-growing trees: 4 patches of 12 eastern cottonwood (Populus deltoides) stem cuttings and 4 patches of 12 American sycamore (Platanus occidentalis) seedlings. To enhance survival and growth, tree patches were subjected to 4 weed control treatments: (1) physical weed barriers, (2) chemical herbicide, (3) both physical and chemical weed control, or (4) no weed control. Overall, first-year survival of cottonwood and sycamore was 25 percent and 47 percent, respectively. Second-year survival of extant trees was 52 percent for cottonwood and 77 percent for sycamore. Physical weed barriers increased survival of cottonwoods to 30 percent versus 18 percent survival with no weed control. Similarly, sycamore survival was increased from 49 percent without weed control to 64 percent with physical weed barriers. Chemical weed control adversely impacted sycamore and reduced survival to 35 percent. Tree heights did not differ between species or among weed control treatments. Girdling of trees by deer often destroyed saplings. Thus, little increase in vertical structure was detected between growing seasons. Application of fertilizer and protection via tree shelters did not improve survival or vertical development of sycamore or cottonwood.

Twedt, D. J.; Wilson, R.R.



Wild fruit trees and shrubs of Southern Africa: Geographic distribution of species richness  

Microsoft Academic Search

Fruit trees and shrubs dominate the edible flora of Africa. Does their geographic distribution differ significantly from that\\u000a of the woody flora in general? Based on analyses of macro-scale geographic variations in the species richness (hereinafter\\u000a SR) of southern Africa’s trees and shrubs, there is a west-to-east trend of increasing edible-fruit-providing SR that is similar\\u000a to that of woody plants

Charles R. Peters



Soil nutrients influence spatial distributions of tropical tree species  

Microsoft Academic Search

and regional scales. At local scales (< 1k m 2), however, habitat factors and species distributions show comparable spatial aggre- gation, making it difficult to disentangle the importance of niche and dispersal processes. In this article, we test soil resource-based niche assembly at a local scale, using species and soil nutrient distributions obtained at high spatial resolution in three diverse

Robert John; J. W. Dalling; K. E. Harms; J. B. Yavitt; R. F. Stallard; Matthew Mirabello; S. P. Hubbell; Renato Valencia; Hugo Navarrete; Martha Vallejo; R. B. Foster



Quantifying tree mortality in a mixed species woodland using multitemporal high spatial resolution satellite imagery  

USGS Publications Warehouse

Widespread tree mortality events have recently been observed in several biomes. To effectively quantify the severity and extent of these events, tools that allow for rapid assessment at the landscape scale are required. Past studies using high spatial resolution satellite imagery have primarily focused on detecting green, red, and gray tree canopies during and shortly after tree damage or mortality has occurred. However, detecting trees in various stages of death is not always possible due to limited availability of archived satellite imagery. Here we assess the capability of high spatial resolution satellite imagery for tree mortality detection in a southwestern U.S. mixed species woodland using archived satellite images acquired prior to mortality and well after dead trees had dropped their leaves. We developed a multistep classification approach that uses: supervised masking of non-tree image elements; bi-temporal (pre- and post-mortality) differencing of normalized difference vegetation index (NDVI) and red:green ratio (RGI); and unsupervised multivariate clustering of pixels into live and dead tree classes using a Gaussian mixture model. Classification accuracies were improved in a final step by tuning the rules of pixel classification using the posterior probabilities of class membership obtained from the Gaussian mixture model. Classifications were produced for two images acquired post-mortality with overall accuracies of 97.9% and 98.5%, respectively. Classified images were combined with land cover data to characterize the spatiotemporal characteristics of tree mortality across areas with differences in tree species composition. We found that 38% of tree crown area was lost during the drought period between 2002 and 2006. The majority of tree mortality during this period was concentrated in piñon-juniper (Pinus edulis-Juniperus monosperma) woodlands. An additional 20% of the tree canopy died or was removed between 2006 and 2011, primarily in areas experiencing wildfire and management activity. -Our results demonstrate that unsupervised clustering of bi-temporal NDVI and RGI differences can be used to detect tree mortality resulting from numerous causes and in several forest cover types.

Garrity, Steven R.; Allen, Craig D.; Brumby, Steven P.; Gangodagamage, Chandana; McDowell, Nate G.; Cai, D. Michael



Tree species control rates of free-living nitrogen fixation in a tropical rain forest.  


Tropical rain forests represent some of the most diverse ecosystems on earth, yet mechanistic links between tree species identity and ecosystem function in these forests remains poorly understood. Here, using free-living nitrogen (N) fixation as a model, we explore the idea that interspecies variation in canopy nutrient concentrations may drive significant local-scale variation in biogeochemical processes. Biological N fixation is the largest "natural" source of newly available N to terrestrial ecosystems, and estimates suggest the highest such inputs occur in tropical ecosystems. While patterns of and controls over N fixation in these systems remain poorly known, the data we do have suggest that chemical differences among tree species canopies could affect free-living N fixation rates. In a diverse lowland rain forest in Costa Rica, we established a series of vertical, canopy-to-soil profiles for six common canopy tree species, and we measured free-living N fixation rates and multiple aspects of chemistry of live canopy leaves, senesced canopy leaves, bulk leaf litter, and soil for eight individuals of each tree species. Free-living N fixation rates varied significantly among tree species for all four components, and independent of species identity, rates of N fixation ranged by orders of magnitude along the vertical profile. Our data suggest that variations in phosphorus (P) concentration drove a significant fraction of the observed species-specific variation in free-living N fixation rates within each layer of the vertical profile. Furthermore, our data suggest significant links between canopy and forest floor nutrient concentrations; canopy P was correlated with bulk leaf litter P below individual tree crowns. Thus, canopy chemistry may affect a suite of ecosystem processes not only within the canopy itself, but at and beneath the forest floor as well. PMID:18959329

Reed, Sasha C; Cleveland, Cory C; Townsend, Alan R



Species tree reconstruction of a poorly resolved clade of salamanders (Ambystomatidae) using multiple nuclear loci.  


The analysis of diverse data sets can yield different phylogenetic estimates that challenge systematists to explain the source of discordance. The mole salamanders (family Ambystomatidae) are a classic example of this phylogenetic conflict. Previous attempts to resolve the ambystomatid species tree using allozymic, morphological, and mitochondrial sequence data have yielded different estimates, making it unclear which data source best approximates ambystomatid phylogeny and which ones yield phylogenetically inaccurate reconstructions. To shed light on this conflict, we present the first multi-locus DNA sequence-based phylogenetic study of the Ambystomatidae. We utilized a range of analyses, including coalescent-based methods of species-tree estimation that account for incomplete lineage sorting within a locus and concordance-based methods that estimate the number of sampled loci that support a particular clade. We repeated these analyses with the removal of individual loci to determine if any locus has a disproportionate effect on our phylogenetic results. Collectively, these results robustly resolved many deep and relatively shallow clades within Ambystoma, including the placement of A. gracile and A. talpoideum as the sister clade to a clade containing all remaining ambystomatids, and the placement of A. maculatum as the sister lineage to all remaining ambystomatids excluding A. gracile and A. talpoideum. Both Bayesian coalescent and concordance methods produced similar results, highlighting strongly supported branches in the species tree. Furthermore, coalescent-based analyses that excluded loci produced overlapping species-tree posterior distributions, suggesting that no particular locus--including mtDNA--disproportionately contributed to our species-tree estimates. Overall, our phylogenetic estimates have greater similarity with previous allozyme and mitochondrial sequence-based phylogenetic estimates. However, intermediate depths of divergence in the ambystomatid species tree remain unresolved, potentially highlighting a region of rapid species radiation or a hard polytomy, which limits our ability to comment on previous morphologically-based taxonomic groups. PMID:23632032

Williams, Joshua S; Niedzwiecki, John H; Weisrock, David W



Distribution patterns of tree species in an evergreen broadleaved forest in eastern China  

Microsoft Academic Search

Ecological assembly rules in evergreen broad-leaved forest are far from clear understanding. Spatial dispersion of individuals\\u000a in a species is central in ecological theory. We analyzed the spatial patterns as well as associations between adult and juvenile\\u000a of each tree species in a 5-ha subtropical evergreen broad-leaved forest plot in eastern China. Out of the 74 species occurring\\u000a with more

Zhengrong Luo; Bingyang Ding; Xiangcheng Mi; Jiuhua Yu; Yougui Wu



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

Microsoft Academic Search

In spring 2002, ambrosia beetles (Coleoptera: Scolytidae) infested an intensively managed 22-ha tree plantation on the upper coastal plain of South Carolina. Nearly 3,500 scolytids representing 28 species were captured in ethanol-baited traps from 18 June 2002 to 18 April 2004. More than 88% of total captures were exotic species. Five species (Dryoxylon onoharaensum (Murayama), Euwallacea validus (Eichhoff), Pseudopityophthorus minutissimus

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



A Climate Change Atlas For 80 Forest Tree Species Of The Eastern United States  

NSDL National Science Digital Library

This is a tree species distribution atlas. It contains information for 80 species in the eastern half of the United States (east of the 100th meridian). The site contains distribution maps and tables for different climate change scenarios, life-history and disturbance attributes, ecological attributes, forest type maps, sorted lists of species importance values (by state and county) for different climate change scenarios, and more.

Prasad, Anantha; Iverson, Louis


Potential colonization of newly available tree-species habitat under ...  


Research & Development ... For each cell outside the current boundary, SHIFT creates an estimate of the probability that each unoccupied target cell ... However , humans could hasten the migration of certain species by physically moving the ...


Improved method of in vitro regeneration in Leucaena leucocephala - a leguminous pulpwood tree species.  


Leucaena leucocephala is a fast growing multipurpose legume tree used for forage, leaf manure, paper and pulp. Lignin in Leucaena pulp adversely influences the quality of paper produced. Developing transgenic Leucaena with altered lignin by genetic engineering demands an optimized regeneration system. The present study deals with optimization of regeneration system for L. leucocephala cv. K636. Multiple shoot induction from the cotyledonary nodes of L. leucocephala was studied in response to cytokinins, thidiazuron (TDZ) and N(6)-benzyladenine (BA) supplemented in half strength MS (½-MS) medium and also their effect on in vitro rooting of the regenerated shoots. Multiple shoots were induced from cotyledonary nodes at varied frequencies depending on the type and concentration of cytokinin used in the medium. TDZ was found to induce more number of shoots per explant than BA, with a maximum of 7 shoots at an optimum concentration of 0.23 µM. Further increase in TDZ concentration resulted in reduced shoot length and fasciation of the shoots. Liquid pulse treatment of the explants with TDZ did not improve the shoot production further but improved the subsequent rooting of the shoots that regenerated. Regenerated shoots successfully rooted on ½-MS medium supplemented with 0.54 µM ?-naphthaleneacetic acid (NAA). Rooted shoots of Leucaena were transferred to coco-peat and hardened plantlets showed ? 90 % establishment in the green house. PMID:23572941

Shaik, Noor M; Arha, Manish; Nookaraju, A; Gupta, Sushim K; Srivastava, Sameer; Yadav, Arun K; Kulkarni, Pallavi S; Abhilash, O U; Vishwakarma, Rishi K; Singh, Somesh; Tatkare, Rajeshri; Chinnathambi, Kannan; Rawal, Shuban K; Khan, Bashir M



Functional traits explain light and size response of growth rates in tropical tree species.  


Relationships between functional traits and average or potential demographic rates have provided insight into the functional constraints and trade-offs underlying life-history strategies of tropical tree species. We have extended this framework by decomposing growth rates of -130 000 trees of 171 Neotropical tree species into intrinsic growth and the response of growth to light and size. We related these growth characteristics to multiple functional traits (wood density, adult stature, seed mass, leaf traits) in a hierarchical Bayesian model that accounted for measurement error and intraspecific variability of functional traits. Wood density was the most important trait determining all three growth characteristics. Intrinsic growth rates were additionally strongly related to adult stature, while all traits contributed to light response. Our analysis yielded a predictive model that allows estimation of growth characteristics for rare species on the basis of a few easily measurable morphological traits. PMID:23431593

Rüger, Nadja; Wirth, Christian; Wright, S Joseph; Condit, Richard



Carbon, nitrogen and phosphorus mineralization of tree leaves and manure  

Microsoft Academic Search

Farmers in developing countries cannot afford inorganic fertilizers. Multipurpose tree leaves or livestock manure are major\\u000a sources of nutrients for soil fertility replenishment. Nutrient release from these organic inputs depends on their chemical\\u000a composition and on soil properties. This study determined the chemical composition of leaves of four African browse species\\u000a and manure from goats fed leaves as protein supplements,

P. L. Mafongoya; P. Barak; J. D. Reed



Genetic variation in a tropical tree species influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem.  


Genetic differences among tree species, their hybrids and within tree species are known to influence associated ecological communities and ecosystem processes in areas of limited species diversity. The extent to which this same phenomenon occurs based on genetic variation within a single tree species, in a diverse complex ecosystem such as a tropical forest, is unknown. The level of biodiversity and complexity of the ecosystem may reduce the impact of a single tree species on associated communities. We assessed the influence of within-species genetic variation in the tree Brosimum alicastrum (Moraceae) on associated epiphytic and invertebrate communities in a neotropical rainforest. We found a significant positive association between genetic distance of trees and community difference of the epiphytic plants growing on the tree, the invertebrates living among the leaf litter around the base of the tree, and the invertebrates found on the tree trunk. This means that the more genetically similar trees are host to more similar epiphyte and invertebrate communities. Our work has implications for whole ecosystem conservation management, since maintaining sufficient genetic diversity at the primary producer level will enhance species diversity of other plants and animals. PMID:21444307

Zytynska, Sharon E; Fay, Michael F; Penney, David; Preziosi, Richard F



A Phylogenetic Perspective on the Individual Species-Area Relationship in Temperate and Tropical Tree Communities  

PubMed Central

Ecologists have historically used species-area relationships (SARs) as a tool to understand the spatial distribution of species. Recent work has extended SARs to focus on individual-level distributions to generate individual species area relationships (ISARs). The ISAR approach quantifies whether individuals of a species tend have more or less species richness surrounding them than expected by chance. By identifying richness ‘accumulators’ and ‘repellers’, respectively, the ISAR approach has been used to infer the relative importance of abiotic and biotic interactions and neutrality. A clear limitation of the SAR and ISAR approaches is that all species are treated as evolutionarily independent and that a large amount of work has now shown that local tree neighborhoods exhibit non-random phylogenetic structure given the species richness. Here, we use nine tropical and temperate forest dynamics plots to ask: (i) do ISARs change predictably across latitude?; (ii) is the phylogenetic diversity in the neighborhood of species accumulators and repellers higher or lower than that expected given the observed species richness?; and (iii) do species accumulators, repellers distributed non-randomly on the community phylogenetic tree? The results indicate no clear trend in ISARs from the temperate zone to the tropics and that the phylogenetic diversity surrounding the individuals of species is generally only non-random on very local scales. Interestingly the distribution of species accumulators and repellers was non-random on the community phylogenies suggesting the presence of phylogenetic signal in the ISAR across latitude.

Yang, Jie; Swenson, Nathan G.; Cao, Min; Chuyong, George B.; Ewango, Corneille E. N.; Howe, Robert; Kenfack, David; Thomas, Duncan; Wolf, Amy; Lin, Luxiang



Diversity makes a difference: Farmers managing inter- and intra-specific tree species diversity in Meru Kenya  

Microsoft Academic Search

Farmers plant trees in pursuit of their livelihood goals of income generation, risk management, household food security and optimum use of available land, labour and capital. Trees also play a crucial role in the cultural life of people. The many products, services and roles needed by people to be fulfilled by trees cannot be provided by only a few species.

A. G. Lengkeek



Effects of stand age and tree species on canopy transpiration and average stomatal conductance of boreal forests  

Microsoft Academic Search

We quantified the effect of stand age and tree species com- position on canopy transpiration ( E C ) by analysing transpi- ration per unit leaf area ( E L ) and canopy stomatal conductance ( G S ) for boreal trees comprising a five stand wildfire chronosequence. A total of 196 sap flux sensors were used on 90 trees




Log Susceptibility of Iberian Tree Species to Phytophthora ramorum1  

Microsoft Academic Search

Phytophthora ramorum is a plant pathogen introduced into Europe and North America. It can infect any host species belonging to different botanical families within the seed plants. Such infective capacity indicates that it can overcome basic plant defence responses that have been phylogenetically conserved in plants (Heath 1991). In addition, P. ramorum is capable of infecting woody plants that are

Eduardo Moralejo; José Andrés García-Muñoz; Enrique Descals


Whitefly Pest Species (Homoptera: Aleyrodidae) on Citrus Trees  

Microsoft Academic Search

SUMMARY Today, the Citrus whitefly, Dialeurodes citri (Ashmead), is a very important pest on all Citrus species throughout the citrus growing areas in Croatia. It causes direct damage by sucking the plant juice from the leaves. Furthermore, immatures excrete honeydew that stimulates sooy mold. The presence of sooty mold on contaminated leaves interferes with the photosynthesis of plants. Citrus fruits

Sonja KAI


Site-Index Comparisons for Tree Species in Northern Minnesota.  

National Technical Information Service (NTIS)

The report presents site-index comparisons for the following forest species in northern Minnesota: quaking aspen, paper birch, basswood, red oak, black ash, jack pine, red pine, white pine, white spruce, black spruce, balsam fir, white-cedar, and tamarack...

W. H. Carmean A. Vasilevsky



Radial variation in sap flow in five laurel forest tree species in Tenerife, Canary Islands.  


Variations in radial patterns of xylem water content and sap flow rate were measured in five laurel forest tree species (Laurus azorica (Seub.) Franco, Persea indica (L.) Spreng., Myrica faya Ait., Erica arborea L. and Ilex perado Ait. ssp. platyphylla (Webb & Berth.) Tutin) growing in an experimental plot at Agua García, Tenerife, Canary Islands. Measurements were performed around midday during warm and sunny days by the heat field deformation method. In all species, water content was almost constant (around 35% by volume) over the whole xylem cross-sectional area. There were no differences in wood color over the whole cross-sectional area of the stem in most species with the exception of E. arborea, whose wood became darker in the inner layers. Radial patterns of sap flow were highly variable and did not show clear relationships with tree diameter or species. Sap flow occurred over the whole xylem cross-sectional area in some species, whereas it was limited to the outer xylem layers in others. Sap flow rate was either similar along the xylem radius or exhibited a peak in the outer part of the xylem area. Low sap flow rates with little variation in radial pattern were typical for shaded suppressed trees, whereas dominant trees exhibited high sap flow rates with a peak in the radial pattern. Stem damage resulted in a significant decrease in sap flow rate in the outer xylem layers. The outer xylem is more important for whole tree water supply than the inner xylem because of its larger size. We conclude that measurement of radial flow pattern provides a reliable method of integrating sap flow from individual measuring points to the whole tree. PMID:12651490

Jiménez, M. Soledad; Nadezhdina, Nadezhda; Cermák, Jan; Morales, Domingo



Analyzing tropical forest tree species abundance distributions using a nonneutral model and through approximate Bayesian inference.  


The neutral theory of biodiversity challenges the classical niche-based view of ecological communities, where species attributes and environmental conditions jointly determine community composition. Functional equivalence among species, as assumed by neutral ecological theory, has been recurrently falsified, yet many patterns of tropical tree communities appear consistent with neutral predictions. This may mean that neutral theory is a good first-approximation theory or that species abundance data sets contain too little information to reject neutrality. Here we present a simple test of neutrality based on species abundance distributions in ecological communities. Based on this test, we show that deviations from neutrality are more frequent than previously thought in tropical forest trees, especially at small spatial scales. We then develop a nonneutral model that generalizes Hubbell's dispersal-limited neutral model in a simple way by including one additional parameter of frequency dependence. We also develop a statistical method to infer the parameters of this model from empirical data by approximate Bayesian computation. In more than half of the permanent tree plots, we show that our new model fits the data better than does the neutral model. Finally, we discuss whether observed deviations from neutrality may be interpreted as the signature of environmental filtering on tropical tree species abundance distributions. PMID:21750378

Jabot, Franck; Chave, Jérôme



Forest floor leachate fluxes under six different tree species on a metal contaminated site.  


Trees play an important role in the biogeochemical cycling of metals, although the influence of different tree species on the mobilization of metals is not yet clear. This study examined effects of six tree species on fluxes of Cd, Zn, DOC, H(+) and base cations in forest floor leachates on a metal polluted site in Belgium. Forest floor leachates were sampled with zero-tension lysimeters in a 12-year-old post-agricultural forest on a sandy soil. The tree species included were silver birch (Betula pendula), oak (Quercus robur and Q. petraea), black locust (Robinia pseudoacacia), aspen (Populus tremula), Scots pine (Pinus sylvestris) and Douglas fir (Pseudotsuga menziesii). We show that total Cd fluxes in forest floor leachate under aspen were slightly higher than those in the other species' leachates, yet the relative differences between the species were considerably smaller when looking at dissolved Cd fluxes. The latter was probably caused by extremely low H(+) amounts leaching from aspen's forest floor. No tree species effect was found for Zn leachate fluxes. We expected higher metal leachate fluxes under aspen as its leaf litter was significantly contaminated with Cd and Zn. We propose that the low amounts of Cd and Zn leaching under aspen's forest floor were possibly caused by high activity of soil biota, for example burrowing earthworms. Furthermore, our results reveal that Scots pine and oak were characterized by high H(+) and DOC fluxes as well as low base cation fluxes in their forest floor leachates, implying that those species might enhance metal mobilization in the soil profile and thus bear a potential risk for belowground metal dispersion. PMID:23376521

Van Nevel, Lotte; Mertens, Jan; De Schrijver, An; Baeten, Lander; De Neve, Stefaan; Tack, Filip M G; Meers, Erik; Verheyen, Kris



Certified and Uncertified Logging Concessions Compared in Gabon: Changes in Stand Structure, Tree Species, and Biomass  

NASA Astrophysics Data System (ADS)

Forest management certification is assumed to promote sustainable forest management, but there is little field-based evidence to support this claim. To help fill this gap, we compared a Forest Stewardship Council (FSC)-certified with an adjacent uncertified, conventionally logged concession (CL) in Gabon on the basis of logging damage, above-ground biomass (AGB), and tree species diversity and composition. Before logging, we marked, mapped, and measured all trees >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and tree damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m3/ha (0.39 trees/ha) and 11.4 m3/ha (0.76 trees/ha). For each tree felled, averages of 9.1 and 20.9 other trees were damaged in the FSC and CL plots, respectively; when expressed as the impacts per timber volume extracted, the values did not differ between the two treatments. Skid trails covered 2.9 % more of the CL surface, but skid trail length per unit timber volume extracted was not greater. Logging roads were wider in the CL than FSC site and disturbed 4.7 % more of the surface. Overall, logging caused declines in AGB of 7.1 and 13.4 % at the FSC and CL sites, respectively. Changes in tree species composition were small but greater for the CL site. Based on these findings and in light of the pseudoreplicated study design with less-than perfect counterfactual, we cautiously conclude that certification yields environmental benefits even after accounting for differences in logging intensities.

Medjibe, V. P.; Putz, Francis E.; Romero, Claudia



Certified and uncertified logging concessions compared in Gabon: changes in stand structure, tree species, and biomass.  


Forest management certification is assumed to promote sustainable forest management, but there is little field-based evidence to support this claim. To help fill this gap, we compared a Forest Stewardship Council (FSC)-certified with an adjacent uncertified, conventionally logged concession (CL) in Gabon on the basis of logging damage, above-ground biomass (AGB), and tree species diversity and composition. Before logging, we marked, mapped, and measured all trees >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and tree damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m(3)/ha (0.39 trees/ha) and 11.4 m(3)/ha (0.76 trees/ha). For each tree felled, averages of 9.1 and 20.9 other trees were damaged in the FSC and CL plots, respectively; when expressed as the impacts per timber volume extracted, the values did not differ between the two treatments. Skid trails covered 2.9 % more of the CL surface, but skid trail length per unit timber volume extracted was not greater. Logging roads were wider in the CL than FSC site and disturbed 4.7 % more of the surface. Overall, logging caused declines in AGB of 7.1 and 13.4 % at the FSC and CL sites, respectively. Changes in tree species composition were small but greater for the CL site. Based on these findings and in light of the pseudoreplicated study design with less-than perfect counterfactual, we cautiously conclude that certification yields environmental benefits even after accounting for differences in logging intensities. PMID:23277438

Medjibe, V P; Putz, Francis E; Romero, Claudia



Sustainable multipurpose tree production systems for Nepal  

SciTech Connect

Argonne National Laboratory is developing methods for producing reforestation plating stock, fuel, and fodder in a sustainable manner in Nepal. This project, in cooperation with the Ministry of Forest and Soil Conservation of Nepal, is sponsored by the US Agency for International Development (AID). Several production systems are being evaluated for the Mid-Hills Region of Nepal. To provide sustainable biomass production and ecological management of the fragile Mid-Hills Region, the production systems must simultaneously satisfy the physiological requirements of the plants, the symbiotic requirements of the plant and the microorganisms in its rhizosphere, the physicochemical requirements of nutrient and water cycling, and the climatic and topographic constraints.

Shen, S.Y.; Kilpatrick, K.J.



Tree species identity and interactions with neighbors determine nutrient leaching in model tropical forests.  


An ecosystem containing a mixture of species that differ in phenology, morphology, and physiology might be expected to resist leaching of soil nutrients to a greater extent than one composed of a single species. We tested the effects of species identity and plant-life-form richness on nutrient leaching at a lowland tropical site where deep infiltration averages >2 m year(-1). Three indigenous tree species with contrasting leafing phenologies (evergreen, dry-season deciduous, and wet-season deciduous) were grown in monoculture and together with two other life-forms with which they commonly occur in tropical forests: a palm and a giant, perennial herb. To calculate nutrient leaching over an 11-year period, concentrations of nutrients in soil water were multiplied by drainage rates estimated from a water balance. The effect of plant-life-form richness on retention differed according to tree species identity and nutrient. Nitrate retention was greater in polycultures of the dry-season deciduous tree species (mean of 7.4 kg ha(-1) year(-1) of NO(3)-N lost compared to 12.7 in monoculture), and calcium and magnesium retention were greater in polycultures of the evergreen and wet-season deciduous tree species. Complementary use of light led to intensification of soil exploitation by roots, the main agent responsible for enhanced nutrient retention in some polycultures. Other mechanisms included differences in nutrient demand among species, and avoidance of catastrophic failure due to episodic weather events or pest outbreaks. Even unrealistically simple multi-life-form mimics of tropical forest can safeguard a site's nutrient capital if careful attention is paid to species' characteristics and temporal changes in interspecific interactions. PMID:21691855

Ewel, John J; Bigelow, Seth W



Influences of calcium availability and tree species on Ca isotope fractionation in soil and vegetation  

USGS Publications Warehouse

The calcium (Ca) isotope system is potentially of great use for understanding biogeochemical processes at multiple scales in forest ecosystems, yet remains largely unexplored for this purpose. In order to further our understanding of Ca behavior in forests, we examined two nearly adjacent hardwood-dominated catchments with differing soil Ca concentrations, developed from crystalline bedrock, to determine the variability of 44Ca/ 40Ca ratios (expressed as ??44Ca) within soil and vegetation pools. For both sugar maple and American beech, the Ca isotope compositions of the measured roots and calculated bulk trees were considerably lighter than those of soil pools at these sites, suggesting that the trees were able to preferentially take up light Ca at the root-soil interface. The Ca isotope compositions of three of four root samples were among the lightest values yet reported for terrestrial materials (??44Ca ???-3.95???). Our results further indicate that Ca isotopes were fractionated along the transpiration streams of both tree species with roots having the least ??44Ca values and leaf litter the greatest. An approximately 2??? difference in ??44Ca values between roots and leaf litter of both tree species suggests a persistent fractionation mechanism along the transpiration stream, likely related to Ca binding in wood tissue coupled with internal ion exchange. Finally, our data indicate that differing tree species demand for Ca and soil Ca concentrations together may influence Ca isotope distribution within the trees. Inter-catchment differences in Ca isotope distributions in soils and trees were minor, indicating that the results of our study may have broad transferability to studies of forest ecosystems in catchments developed on crystalline substrates elsewhere. ?? 2008 Springer Science+Business Media B.V.

Page, B. D.; Bullen, T. D.; Mitchell, M. J.



Leaf gas exchange traits of domestic and exotic tree species in Cambodia  

NASA Astrophysics Data System (ADS)

In forests under the management by community villagers, exotic tree species with rapid growth rate are introduced in wide range of Cambodia. To evaluate the influence of the introduction on the forest gas exchange and water budget, we investigated the leaf gas exchange traits of two domestic (Dipterocarpus obtusifolius and Shorea roxburghii) and exotic tree species (Acasia auriculiformis and Eucalyptus camadilansis). We sampled shoots of each species and measured the leaf gas exchange traits (photosynthetic rates under different CO2 concentrations, transpiration rate and stomatal conductance) (6 leaves x 3 trees x 4 species). We carried out this measurement at 2 months intervals for a year from the beginning of rainy season and compared the obtained traits among species. Light saturated rate of net photosynthesis was higher in E. camadilansis but did not differ among other species both in rainy and dry seasons. Seasonal patter in photosynthetic traits was not obvious. Each species changed stomatal conductance in response to changes in environmental conditions. The response was more sensitive than reported values. In this presentation, we show details about the basic information about the leaf-level gas exchange traits, which are required to run soil- vegetation - atmosphere transfer model.

Miyazawa, Y.; Tateishi, M.; Kumagai, T.; Otsuki, K.



Modern tree species composition reflects ancient Maya "forest gardens" in northwest Belize.  


Ecology and ethnobotany were integrated to assess the impact of ancient Maya tree-dominated home gardens (i.e., "forest gardens"), which contained a diversity of tree species used for daily household needs, on the modern tree species composition of a Mesoamerican forest. Researchers have argued that the ubiquity of these ancient gardens throughout Mesoamerica led to the dominance of species useful to Maya in the contemporary forest, but this pattern may be localized depending on ancient land use. The tested hypothesis was that species composition would be significantly different between areas of dense ancient residential structures (high density) and areas of little or no ancient settlement (low density). Sixty-three 400-m2 plots (31 high density and 32 low density) were censused around the El Pilar Archaeological Reserve in northwestern Belize. Species composition was significantly different, with higher abundances of commonly utilized "forest garden" species still persisting in high-density forest areas despite centuries of abandonment. Subsequent edaphic analyses only explained 5% of the species composition differences. This research provides data on the long-term impacts of Maya forests gardens for use in development of future conservation models. For Mesoamerican conservation programs to work, we must understand the complex ecological and social interactions within an ecosystem that developed in intimate association with humans. PMID:21516889

Ross, Nanci J



Epigenetic regulation of adaptive responses of forest tree species to the environment  

PubMed Central

Epigenetic variation is likely to contribute to the phenotypic plasticity and adaptative capacity of plant species, and may be especially important for long-lived organisms with complex life cycles, including forest trees. Diverse environmental stresses and hybridization/polyploidization events can create reversible heritable epigenetic marks that can be transmitted to subsequent generations as a form of molecular “memory”. Epigenetic changes might also contribute to the ability of plants to colonize or persist in variable environments. In this review, we provide an overview of recent data on epigenetic mechanisms involved in developmental processes and responses to environmental cues in plant, with a focus on forest tree species. We consider the possible role of forest tree epigenetics as a new source of adaptive traits in plant breeding, biotechnology, and ecosystem conservation under rapid climate change.

Brautigam, Katharina; Vining, Kelly J; Lafon-Placette, Clement; Fossdal, Carl G; Mirouze, Marie; Marcos, Jose Gutierrez; Fluch, Silvia; Fraga, Mario Fernandez; Guevara, M Angeles; Abarca, Dolores; Johnsen, ?ystein; Maury, Stephane; Strauss, Steven H; Campbell, Malcolm M; Rohde, Antje; Diaz-Sala, Carmen; Cervera, Maria-Teresa



Neither Host-specific nor Random: Vascular Epiphytes on Three Tree Species in a Panamanian Lowland Forest  

PubMed Central

• Background and Aims A possible role of host tree identity in the structuring of vascular epiphyte communities has attracted scientific attention for decades. Specifically, it has been suggested that each host tree species has a specific subset of the local species pool according to its own set of properties, e.g. physicochemical characteristics of the bark, tree architecture, or leaf phenology patterns. • Methods A novel, quantitative approach to this question is presented, taking advantage of a complete census of the vascular epiphyte community in 0·4 ha of undisturbed lowland forest in Panama. For three locally common host-tree species (Socratea exorrhiza, Marila laxiflora, Perebea xanthochyma) null models were created of the expected epiphyte assemblages assuming that epiphyte colonization reflected random distribution of epiphytes in the forest. • Key Results In all three tree species, abundances of the majority of epiphyte species (69–81?%) were indistinguishable from random, while the remaining species were about equally over- or under-represented compared with their occurrence in the entire forest plot. Permutations based on the number of colonized trees (reflecting observed spatial patchiness) yielded similar results. Finally, a third analysis (canonical correspondence analysis) also confirmed host-specific differences in epiphyte assemblages. In spite of pronounced preferences of some epiphytes for particular host trees, no epiphyte species was restricted to a single host. • Conclusions The epiphytes on a given tree species are not simply a random sample of the local species pool, but there are no indications of host specificity either.




Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam's Avifauna  

Microsoft Academic Search

Predation by brown tree snakes ( Boiga irregularis ) devastated the avifauna of Guam in the Mari- ana Islands during the last half of the twentieth century, causing the extirpation or serious reduction of most of the island's 25 resident bird species. Past studies have provided qualitative descriptions of the decline of na- tive forest birds but have not considered

Gary J. Wiles; Jonathan Bart; ROBERT E. BECK JR.; Celestino F. Aguon



Photosynthetic responses to light in seedlings of selected Amazonian and Australian rainforest tree species  

Microsoft Academic Search

Seedlings of the Caesalpinoids Hymenaea courbaril, H. parvifolia and Copaifera venezuelana, emergent trees of Amazonian rainforest canopies, and of the Araucarian conifers Agathis microstachya and A. robusta, important elements in tropical Australian rainforests, were grown at 6% (shade) and 100% full sunlight (sun) in glasshouses. All species produced more leaves in full sunlight than in shade and leaves of sun

J. H. Langenheim; C. B. Osmond; A. Brooks; P. J. Ferrar



Species diversity and seasonal dynamics of Acari on abandoned apple trees in southern Ontario, Canada  

Microsoft Academic Search

Foliage-inhabiting mites and associated insects were observed over a 3-year period on abandoned apple trees at two sites in southern Ontario. This study included species diversity and seasonal dynamics as well as the total habitat size and its seasonal fluctuations. Due to heavy feeding on the leaves in the early season by the fall cankerworm, at one observation site, the

Hiroshi Amano; D. A. Chant



Growth responses to arbuscular mycorrhizae by rain forest seedlings vary with light intensity and tree species  

Microsoft Academic Search

Light intensity and root colonization by arbuscular mycorrhizal (AM) fungi are considered important factors af- fecting the performance of rain forest plants, yet few studies have examined how these two factors interact. Whether AM colonization promoted growth or caused shifts in biomass allocation in seedlings of four species of Australian rain forest tree (Flindersia brayleana, Acmena resa, Cryptocarya mackinnoniana and

Catherine A. Gehring



Growth responses to arbuscular mycorrhizae by rain forest seedlings vary with light intensity and tree species  

Microsoft Academic Search

Light intensity and root colonization by arbuscular mycorrhizal (AM) fungi are considered important factors affecting the performance of rain forest plants, yet few studies have examined how these two factors interact. Whether AM colonization promoted growth or caused shifts in biomass allocation in seedlings of four species of Australian rain forest tree (Flindersia brayleana, Acmena resa, Cryptocarya mackinnoniana and Cryptocarya

Catherine A. Gehring



Nematicidal activity of leaves of common shrub and tree species from Southern Chile against Meloidogyne hapla  

Microsoft Academic Search

L. Böhm, N. Arismendi, and L. Ciampi. 2009. Nematicidal activity of leaves of common shrub and tree species from Southern Chile against Meloidogyne hapla. Cien. Inv. Agr. 36 (2): 249-258. The biological control of the root-knot nematode, Meloidogyne hapla, was evaluated through the addition of organic amendments of dry and chopped leaves of Buddleja globosa, Drymis winteri, Eucalyptus globulus, Gevuina

Laura Böhm; Nolberto Arismendi; Luigi Ciampi



Simulated Multispectral Imagery for Tree Species Classification Using Support Vector Machines  

Microsoft Academic Search

The information content of remotely sensed data depends primarily on the spatial and spectral properties of the imaging device. This paper focuses on the classification performance of the different spectral features (hyper- and multispectral measurements) with respect to three tree species. The Support Vector Machine was chosen as the classification algorithm for these features. A simulated optical radiation model was

Ville Heikkinen; Timo Tokola; Jussi Parkkinen; Ilkka Korpela; Timo Jaaskelainen



An SVM Classification of Tree Species Radiometric Signatures Based on the Leica ADS40 Sensor  

Microsoft Academic Search

This paper focuses on the use of multispectral mea- surements to classify remotely sensed radiance and reflectance information into three tree species, Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), and birch (Betula pubescens Ehrh., Betula pendula Roth), using a Support Vector Machine (SVM) algorithm. The features used for the classifier are radiometric involving different viewing

Ville Heikkinen; Ilkka Korpela; Timo Tokola; Eija Honkavaara; Jussi Parkkinen



An object-oriented forest landscape model and its representation of tree species  

Microsoft Academic Search

LANDIS is a forest landscape model that simulates the interaction of large landscape processes and forest successional dynamics at tree species level. We discuss how object-oriented design (OOD) approaches such as modularity, abstraction and encapsulation are integrated into the design of LANDIS. We show that using OOD approaches, model decisions (often as model assumptions) can be made at three levels

Hong S. He; David J. Mladenoff; Joel Boeder



Canopy tree-soil interactions within temperate forest: species effects on soil carbon and nitrogen  

Microsoft Academic Search

In a northwestern Connecticut forest, we quantified the carbon (C) and ni- trogen (N) content of the forest floor and the top 15 cm of mineral soil and the rate of midsummer net N mineralization beneath six different tree species. There were large in- terspecific differences in forest floor depth and mass, in the size and distribution of C and

Adrien C. Finzi; Nico Van Breemen; Charles D. Canham



Biomass relationships for tree species in regenerating semi-deciduous tropical moist forest in Cameroon  

Microsoft Academic Search

To enable carbon accumulation in regenerating tropical forest to be assessed, regression equations which permit the estimation of above and below ground biomass from measurements of stem diameter (D) and height (H) were derived from destructive harvests and dimensions of 14 trees distributed among five species in the moist tropical forest zone of Cameroon. Coarse root biomass (over 10 mm

J. D. Deans; J. Moran; J. Grace



Vertical structure and spatial associations of dominant tree species in an old-growth temperate forest  

Microsoft Academic Search

A 25-ha broad-leaved Korean pine (Pinus koraiensis) mixed forest plot was established on Changbai Mountain, PR China, in 2004 in order to gain insights into the processes driving regeneration and succession of the forest. All trees at least 1cm in diameter at breast height were mapped and identified to species. In this study, the spatial distribution patterns and spatial associations

Zhanqing Hao; Jian Zhang; Bo Song; Ji Ye; Buhang Li



Preliminary operational genetic management units of a highly fragmented forest tree species of southern South America  

Microsoft Academic Search

The management of the genetic resources of any wild species requires the definition of genetically homogeneous units about which practical decisions can be taken. To this end, a structure analysis was performed on the Patagonian cypress Austrocedrus chilensis (D.Don) Pic. Ser. et Bizzarri. A total of 746 seed trees corresponding to 27 natural populations sampled across its entire Argentinean range

Mario J. Pastorino; Leonardo A. Gallo



Pre-epidemic Mortality Rates for Common Phytophthora ramorum Host Tree Species in California1  

Microsoft Academic Search

Understanding the impacts of Phytophthora ramorum on forests will require knowledge of pre-disease distribution, abundance, and rates of change for affected species. This study estimated pre-epidemic mortality rates for nine common host tree species: bigleaf maple (Acer macrophyllum), California bay laurel (Umbellularia californica), California black oak (Quercus kelloggii), canyon live oak (Quercus chrysolepis), coast live oak (Quercus agrifolia), Douglas-fir (Pseudotsuga

T. M. Barrett


Stem and leaf hydraulics of congeneric tree species from adjacent tropical savanna and forest ecosystems  

Microsoft Academic Search

Leaf and stem functional traits related to plant water relations were studied for six congeneric species pairs, each composed\\u000a of one tree species typical of savanna habitats and another typical of adjacent forest habitats, to determine whether there\\u000a were intrinsic differences in plant hydraulics between these two functional types. Only individuals growing in savanna habitats\\u000a were studied. Most stem traits,

Guang-You Hao; William A. Hoffmann; Fabian G. Scholz; Sandra J. Bucci; Frederick C. Meinzer; Augusto C. Franco; Kun-Fang Cao; Guillermo Goldstein



Effects of canopy tree species on belowground biogeochemistry in a lowland wet tropical forest  

USGS Publications Warehouse

Tropical rain forests are known for their high biological diversity, but the effects of plant diversity on important ecosystem processes in this biome remain unclear. Interspecies differences in both the demand for nutrients and in foliar and litter nutrient concentrations could drive variations in both the pool sizes and fluxes of important belowground resources, yet our understanding of the effects and importance of aboveground heterogeneity on belowground biogeochemistry is poor, especially in the species-rich forests of the wet tropics. To investigate the effects of individual tree species on belowground biogeochemical processes, we used both field and laboratory studies to examine how carbon (C), nitrogen (N), and phosphorus (P) cycles vary under nine different canopy tree species – including three legume and six non-legume species – that vary in foliar nutrient concentrations in a wet tropical forest in southwestern Costa Rica. We found significant differences in belowground C, N and P cycling under different canopy tree species: total C, N and P pools in standing litter varied by species, as did total soil and microbial C and N pools. Rates of soil extracellular acid phosphatase activity also varied significantly among species and functional groups, with higher rates of phosphatase activity under legumes. In addition, across all tree species, phosphatase activity was significantly positively correlated with litter N/P ratios, suggesting a tight coupling between relative N and P inputs and resource allocation to P acquisition. Overall, our results suggest the importance of aboveground plant community composition in promoting belowground biogeochemical heterogeneity at relatively small spatial scales.

Keller, Adrienne B.; Reed, Sasha C.; Townsend, Alan R.; Cleveland, Cory C.



Light acclimation of four native tree species in felling gaps within a tropical mountain rainforest  

Microsoft Academic Search

Ecuadorian mountain rainforests are declining dramatically due to deforestation. Exploitation of remaining forests has led\\u000a to low abundances of native, valuable timber species. Enrichment planting of selected native tree species into forest gaps\\u000a is a strategy that may increase their abundance and maintain biodiversity. However, the development of successful planting\\u000a strategies requires knowledge of environmental demands on, and ecological requirements

Daniel Kuptz; Thorsten E. E. Grams; Sven Günter



Isolation of LEAFY and TERMINAL FLOWER 1 homologues from six fruit tree species in the subfamily Maloideae of the Rosaceae  

Microsoft Academic Search

Flowering is an essential stage of fruit production. To understand the molecular mechanisms controlling flowering in maloid fruit tree species, we isolated and analyzed genes homologous to Arabidopsis LEAFY (LFY; flower meristem identity gene) and TERMINAL FLOWER 1 (TFL1; inflorescence meristem identity gene) from six fruit tree species in the subfamily Maloideae of the Rosaceae; apple (Malus × domestica), Japanese

Tomoya Esumi; Ryutaro Tao; Keizo Yonemori



The Exotic Legume Tree Species Acacia holosericea Alters Microbial Soil Functionalities and the Structure of the Arbuscular Mycorrhizal Community  

Microsoft Academic Search

The response of microbial functional diversity as well as its resistance to stress or disturbances caused by the introduction of an exotic tree species, Acacia holosericea, ectomycorrhized or not with Pisolithus albus, was examined. The results show that this ectomycorrhizal fungus promotes drastically the growth of this fast- growing tree species in field conditions after 7 years of plantation. Compared

P. Remigi; A. Faye; A. Kane; M. Deruaz; J. Thioulouse; M. Cissoko; Y. Prin; A. Galiana; B. Dreyfus; R. Duponnois



Soil phosphorus and tree cover modify the effects of livestock grazing on plant species richness in Australian grassy woodland  

Microsoft Academic Search

The effects of grazing on the richness of understorey plant communities are predicted to vary along gradients of resources and tree cover. In temperate Australia livestock management has involved phosphorus addition and tree removal but little research has examined how the effects of grazing on plant species richness may vary with these management regimes. Patterns of understorey plant species richness

Josh Dorrough; Claire Moxham; Vivienne Turner; Geoff Sutter



Nitrogen uptake by four tree species of the Catskill Mountains, New York: Implications for forest N dynamics  

Microsoft Academic Search

Watersheds of the Catskill Mountains, New York have marked differences in nitrogen (N) dynamics among dominant tree species stands. Our objectives were to study how tree species vary in N uptake to better understand the basis for the observed variation in these forested watersheds. We conducted a 15N tracer greenhouse study to determine NH4+ and NO3- uptake of American beech

P. H. Templer; T. E. Dawson



Multipurpose Compact Spectrometric Unit  

NASA Astrophysics Data System (ADS)

A new standalone compact spectrometer was developed. The device consists of analog (peamplifier, amplifier) and digital parts. The digital part is based on the 160 MIPS Digital Signal Processor. It contains 20 Msps Flash-ADC, 1 MB RAM for spectra storage, 128 KB Flash/ROM for firmware storage, Real Time Clock and several voltage regulators providing the power for user peripherals (e.g. amplifier, temperature sensors, etc.). Spectrometer is connected with a notebook via high-speed USB 2.0 bus. The spectrometer is multipurpose device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.

Bo?arov, Viktor; ?ermák, Pavel; Mamedov, Fadahat; Štekl, Ivan



Temperature dependence, spatial scale, and tree species diversity in eastern Asia and North America  

PubMed Central

The increase of biodiversity from poles to equator is one of the most pervasive features of nature. For 2 centuries since von Humboldt, Wallace, and Darwin, biogeographers and ecologists have investigated the environmental and historical factors that determine the latitudinal gradient of species diversity, but the underlying mechanisms remain poorly understood. The recently proposed metabolic theory of ecology (MTE) aims to explain ecological patterns and processes, including geographical patterns of species richness, in terms of the effects of temperature and body size on the metabolism of organisms. Here we use 2 comparable databases of tree distributions in eastern Asia and North America to investigate the roles of environmental temperature and spatial scale in shaping geographical patterns of species diversity. We find that number of species increases exponentially with environmental temperature as predicted by the MTE, and so does the rate of spatial turnover in species composition (slope of the species-area relationship). The magnitude of temperature dependence of species richness increases with spatial scale. Moreover, the relationship between species richness and temperature is much steeper in eastern Asia than in North America: in cold climates at high latitudes there are more tree species in North America, but the reverse is true in warmer climates at lower latitudes. These patterns provide evidence that the kinetics of ecological and evolutionary processes play a major role in the latitudinal pattern of biodiversity.

Wang, Zhiheng; Brown, James H.; Tang, Zhiyao; Fang, Jingyun



Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam's Avifauna  

USGS Publications Warehouse

Predation by brown tree snakes (Boiga irregularis) devastated the avifauna of Guam in the Mariana Islands during the last half of the twentieth century, causing the extirpation or serious reduction of most of the island's 25 resident bird species. Past studies have provided qualitative descriptions of the decline of native forest birds but have not considered all species or presented quantitative analyses. We analyzed two sets of survey data gathered in northern Guam between 1976 and 1998 and reviewed unpublished sources to provide a comprehensive account of the impact of brown tree snakes on the island's birds. Our results indicate that 22 species, including 17 of 18 native species, were severely affected by snakes. Twelve species were likely extirpated as breeding residents on the main island, 8 others experienced declines of ???90% throughout the island or at least in the north, and 2 were kept at reduced population levels during all or much of the study. Declines of ???90% occurred rapidly, averaging just 8.9 years along three roadside survey routes combined and 1.6 years at a 100-ha forested study site. Declines in northern Guam were also relatively synchronous and occurred from about 1976 to 1986 for most species. The most important factor predisposing a species to coexistence with brown tree snakes was its ability to nest and roost at locations where snakes were uncommon. Large clutch size and large body size were also related to longer persistence times, although large body size appeared to delay, but not prevent, extirpation. Our results draw attention to the enormous detrimental impact that brown tree snakes are likely to have upon invading new areas. Increased containment efforts on Guam are needed to prevent further colonizations, but a variety of additional management efforts would also benefit the island's remaining bird populations.

Wiles, G. J.; Bart, J.; Beck, Jr. , R. E.; Aguon, C. F.



The trait contribution to wood decomposition rates of 15 Neotropical tree species.  


The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in species traits on differences in wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 tree species in a Bolivian semi-evergreen tropical moist forest. We hypothesized that interspecific differences in species traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr(-1). We measured 10 different chemical, anatomical, and morphological traits for all species. The species' average traits were useful predictors of wood decomposition rates, particularly the average diameter (dbh) of the tree species (R2 = 0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2 = 0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When dbh values of the actual dead trees sampled for decomposition rate determination were used as a predictor variable, the final model (including dead tree dbh and lignin concentration) explained even more variation in wood decomposition rates (R2 = 0.71), underlining the importance of dbh in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations, and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-species study, in which for the first time a large set of traits is explicitly linked to wood decomposition rates, merits further testing in other forest ecosystems. PMID:21302839

van Geffen, Koert G; Poorter, Lourens; Sass-Klaassen, Ute; van Logtestijn, Richard S P; Cornelissen, Johannes H C



Large difference of inhibitive effect of nitrogen deposition on soil methane oxidation between plantations with N-fixing tree species and non-N-fixing tree species  

NASA Astrophysics Data System (ADS)

The responses of soil methane (CH4) net fluxes to nitrogen (N) addition in a N-fixing tree species (Acacia auriculiformis (AA)) and a non-N-fixing tree species (Eucalyptus citriodora (EU)) plantation were studied in southern China. Treatments were conducted at each plantation with three N levels (0, 50, and 100 kg N ha-1 yr-1 for control, medium-N, and high-N treatment, respectively, abbreviated as C, MN, and HN). From August 2010 to July 2011, CH4 flux was measured biweekly using a static chamber and gas chromatography technique. The soils of both sites acted as sink of atmospheric CH4. The CH4 uptake rate in control of the AA site (36.3 ± 3.2 ?g CH4-C m-2 h-1) was greater than that of the EU plantation (29.9 ± 0.9 ?g CH4-C m-2 h-1). In the AA plantation, the averaged rates of CH4 uptake for the MN (28.6 ± 2.3 ?g CH4-C m-2 h-1) and HN treatment (23.8 ± 2.8 ?g CH4-C m-2 h-1) were decreased by 21% and 35%, respectively, compared to the control. However, there was no change of soil CH4 uptake between N-treated plots and the controls in the EU site. Our results indicated that there might be large difference of inhibitive effect of N deposition on soil CH4 oxidation between the AA and EU plantations. The projected increase of N deposition would weaken the capability of N-fixing tree species plantations for atmospheric CH4 sink in tropical and subtropical regions.

Zhang, Wei; Zhu, Xiaomin; Liu, Lei; Fu, Shenglei; Chen, Hao; Huang, Juan; Lu, Xiankai; Liu, Zhanfeng; Mo, Jiangming



Tree species diversity influences herbivore abundance and damage: meta-analysis of long-term forest experiments.  


Plant monocultures are commonly believed to be more susceptible to herbivore attacks than stands composed of several plant species. However, few studies have experimentally tested the effects of tree species diversity on herbivory. In this paper, we present a meta-analysis of uniformly collected data on insect herbivore abundance and damage on three tree species (silver birch, black alder and sessile oak) from seven long-term forest diversity experiments in boreal and temperate forest zones. Our aim was to compare the effects of forest diversity on herbivores belonging to different feeding guilds and inhabiting different tree species. At the same time we also examined the variation in herbivore responses due to tree age and sampling period within the season, the effects of experimental design (plot size and planting density) and the stability of herbivore responses over time. Herbivore responses varied significantly both among insect feeding guilds and among host tree species. Among insect feeding guilds, only leaf miner densities were consistently lower and less variable in mixed stands as compared to tree monocultures regardless of the host tree species. The responses of other herbivores to forest diversity depended largely on host tree species. Insect herbivory on birch was significantly lower in mixtures than in birch monocultures, whereas insect herbivory on oak and alder was higher in mixtures than in oak and alder monocultures. The effects of tree species diversity were also more pronounced in older trees, in the earlier part of the season, at larger plots and at lower planting density. Overall our results demonstrate that forest diversity does not generally and uniformly reduce insect herbivory and suggest instead that insect herbivore responses to forest diversity are highly variable and strongly dependent on the host tree species and other stand characteristics as well as on the type of the herbivore. PMID:17356813

Vehviläinen, Harri; Koricheva, Julia; Ruohomäki, Kai



Recruitment of tree species visible in a canopy gap in a southern Appalachian forest.  

NSDL National Science Digital Library

Natural recruitment of tree species is visible in a forest canopy gap at Coweeta Long Term Ecological Research (LTER) station in the Southern Appalachians. A recent study investigated temporal variability in seedling establishment in the Appalachians in order to predict the effects of climate change on tree recruitment. Communities found at higher elevations may be in danger of regional extinction if their habitats disappear, which is predicted to occur given the current climatic trends. This photograph originally appeared on the cover of Ecological Monographs (77:2) in May of 2007.

Ibanez, Ines



Complementary Models of Tree Species–Soil Relationships in Old-Growth Temperate Forests  

Microsoft Academic Search

Ecosystem-level studies identify plant–soil feedbacks as important controls on soil nutrient availability, particularly for\\u000a nitrogen and phosphorus. Although site- and species-specific studies of tree species–soil relationships are relatively common,\\u000a comparatively fewer studies consider multiple co-existing species in old-growth forests across a range of sites that vary\\u000a in underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients

Alison Cross; Steven S. Perakis



Comparative hydraulic architecture of tropical tree species representing a range of successional stages and wood density.  


Plant hydraulic architecture (PHA) has been linked to water transport sufficiency, photosynthetic rates, growth form and attendant carbon allocation. Despite its influence on traits central to conferring an overall competitive advantage in a given environment, few studies have examined whether key aspects of PHA are indicative of successional stage, especially within mature individuals. While it is well established that wood density (WD) tends to be lower in early versus late successional tree species, and that WD can influence other aspects of PHA, the interaction of WD, successional stage and the consequent implications for PHA have not been sufficiently explored. Here, we studied differences in PHA at the scales of wood anatomy to whole-tree hydraulic conductance in species in early versus late successional Panamanian tropical forests. Although the trunk WD was indistinguishable between the successional groups, the branch WD was lower in the early successional species. Across all species, WD correlated negatively with vessel diameter and positively with vessel packing density. The ratio of branch:trunk vessel diameter, branch sap flux and whole-tree leaf-specific conductance scaled negatively with branch WD across species. Pioneer species showed greater sap flux in branches than in trunks and a greater leaf-specific hydraulic conductance, suggesting that pioneer species can move greater quantities of water at a given tension gradient. In combination with the greater water storage capacitance associated with lower WD, these results suggest these pioneer species can save on the carbon expenditure needed to build safer xylem and instead allow more carbon to be allocated to rapid growth. PMID:21445684

McCulloh, Katherine A; Meinzer, Frederick C; Sperry, John S; Lachenbruch, Barbara; Voelker, Steven L; Woodruff, David R; Domec, Jean-Christophe



Measurement carbon dioxide concentration does not affect root respiration of nine tree species in the field.  


Inhibition of respiration has been reported as a short-term response of tree roots to elevated measurement CO2 concentration ([CO2]), calling into question the validity of root respiration rates determined at CO2 concentrations that differ from the soil [CO2] in the rooting zone. Our objectives were to validate previous observations of a direct CO2 effect on root respiration in sugar maple (Acer saccharum Marsh.) and to determine if high [CO2] also inhibited root respiration in other tree species. Root respiration rates for nine common North American tree species were measured in the field at ambient soil temperature at both 350 and 1000 microl CO2 l-1. No evidence of direct inhibition of root respiration by elevated measurement [CO2] was found for any of the species tested. The ratio of respiration rates at 1000 and 350 microl CO2 l-1 ranged from 0.97 to 1.07, and the 95% confidence intervals for this ratio included unity for all species tested. Tests of a respiration cuvette used in earlier experiments suggested that gas leakage from the cuvette/IRGA system created an apparent direct CO2 effect on respiration of sugar maple roots when none actually existed. Small sample masses used in those experiments exacerbated the error. Careful attention to the possibility of gas leaks and the avoidance of small sample masses should produce data that will allow researchers to accurately assess whether direct effects of measurement [CO2] exist. Our findings of no direct CO2 effect on respiration of roots of a wide variety of species suggest that such effects may be less common than previously thought for tree roots. PMID:11772557

Burton, Andrew J; Pregitzer, Kurt S



Microbiology of Wetwood: Importance of Pectin Degradation and Clostridium Species in Living Trees  

PubMed Central

Wetwood samples from standing trees of eastern cottonwood (Populus deltoides), black poplar (Populus nigra), and American elm (Ulmus americana) contained high numbers of aerobic and anaerobic pectin-degrading bacteria (104 to 106 cells per g of wood). High activity of polygalacturonate lyase (?0.5 U/ml) was also detected in the fetid liquid that spurted from wetwood zones in the lower trunk when the trees were bored. A prevalent pectin-degrading obligately anaerobic bacterium isolated from these wetwoods was identified as Clostridium butyricum. Pectin decomposition by C. butyricum strain 4P1 was associated with an inducible polygalacturonate lyase and pectin methylesterase, the same types of pectinolytic activity expressed in the wetwood of these trees. The pH optimum of the extracellular polygalacturonate lyase was alkaline (near pH 8.5). In vitro tests with sapwood samples from a conifer (Douglas fir, Pseudotsuga menziesii) showed that tori in membranes of bordered pits are degraded by pure cultures of strain 4P1, polygalacturonate lyase enzyme preparations of strain 4P1, and mixed methanogenic cultures from the tree samples of wetwood. These results provide evidence that pectin in xylem tissue is actively degraded by C. butyricum strain 4P1 via polygalacturonate lyase activity. The importance of pectin degradation by bacteria, including Clostridium species, appears paramount in the formation and maintenance of the wetwood syndrome in certain living trees. Images

Schink, Bernhard; Ward, James C.; Zeikus, J. Gregory



Substrate conditions, foliar nutrients and the distributions of two canopy tree species in a Costa Rican secondary rain forest  

Microsoft Academic Search

A 28 yr old secondary lowland rain forest in Costa Rica was dominated by two tree species of contrasting ecologies, Vochysia ferruginea - a species typical of well-drained but infertile soils of high Al saturation, and Cordia alliodora, a species requiring soils of at least moderate fertility. The two species exhibited markedly different spatial distributions in the forest and we

Bernal Herrera; Bryan Finegan



Diurnal and seasonal carbon balance of four tropical tree species differing in successional status.  


This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality. PMID:19197495

Souza, G M; Ribeiro, R V; Sato, A M; Oliveira, M S



Crown Plasticity and Competition for Canopy Space: A New Spatially Implicit Model Parameterized for 250 North American Tree Species  

PubMed Central

Background Canopy structure, which can be defined as the sum of the sizes, shapes and relative placements of the tree crowns in a forest stand, is central to all aspects of forest ecology. But there is no accepted method for deriving canopy structure from the sizes, species and biomechanical properties of the individual trees in a stand. Any such method must capture the fact that trees are highly plastic in their growth, forming tessellating crown shapes that fill all or most of the canopy space. Methodology/Principal Findings We introduce a new, simple and rapidly-implemented model–the Ideal Tree Distribution, ITD–with tree form (height allometry and crown shape), growth plasticity, and space-filling, at its core. The ITD predicts the canopy status (in or out of canopy), crown depth, and total and exposed crown area of the trees in a stand, given their species, sizes and potential crown shapes. We use maximum likelihood methods, in conjunction with data from over 100,000 trees taken from forests across the coterminous US, to estimate ITD model parameters for 250 North American tree species. With only two free parameters per species–one aggregate parameter to describe crown shape, and one parameter to set the so-called depth bias–the model captures between-species patterns in average canopy status, crown radius, and crown depth, and within-species means of these metrics vs stem diameter. The model also predicts much of the variation in these metrics for a tree of a given species and size, resulting solely from deterministic responses to variation in stand structure. Conclusions/Significance This new model, with parameters for US tree species, opens up new possibilities for understanding and modeling forest dynamics at local and regional scales, and may provide a new way to interpret remote sensing data of forest canopies, including LIDAR and aerial photography.

Purves, Drew W.; Lichstein, Jeremy W.; Pacala, Stephen W.



Tree species diversity influences herbivore abundance and damage: meta-analysis of long-term forest experiments  

Microsoft Academic Search

Plant monocultures are commonly believed to be more susceptible to herbivore attacks than stands composed of several plant\\u000a species. However, few studies have experimentally tested the effects of tree species diversity on herbivory. In this paper,\\u000a we present a meta-analysis of uniformly collected data on insect herbivore abundance and damage on three tree species (silver\\u000a birch, black alder and sessile

Harri Vehviläinen; Julia Koricheva; Kai Ruohomäki



Sap Flux Scaled Transpiration in Ring-porous Tree Species: Assumptions, Pitfalls and Calibration  

NASA Astrophysics Data System (ADS)

Thermal dissipation probes for measuring sap flow (Granier-type) at the whole tree and stand level are routinely used in forest ecology and site water balance studies. While the original empirical relationship used to calculate sap flow was reported as independent of wood anatomy (ring-porous, diffuse-porous, tracheid), it has been suggested that potentially large errors in sap flow calculations may occur when using the original calibration for ring-porous species, due to large radial trends in sap velocity and/or shallow sapwood depth. Despite these concerns, sap flux measurements have rarely been calibrated in ring-porous taxa. We used a simple technique to calibrate thermal dissipation sap flux measurements on ring-porous trees in the lab. Calibration measurements were conducted on five ring-porous species in the Salt Lake City, USA metropolitan area including Quercus gambelii (Gambel oak), Gleditsia triacanthos (Honey locust), Elaeagnus angustifolia (Russian olive), Sophora japonica (Japanese pagoda), and Celtis occidentalis (Common hackberry). Six stems per species of approximately 1 m in length were instrumented with heat dissipation probes to measure sap flux concurrently with gravimetric measurements of water flow through each stem. Safranin dye was pulled through the stems following flow rate measurements to determine sapwood area. As expected, nearly all the conducting sapwood area was limited to regions within the current year growth rings. Consequently, we found that the original Granier equation underestimated sap flux density for all species considered. Our results indicate that the use of thermal dissipation probes for measuring sap flow in ring-porous species should be independently calibrated, particularly when species- specific calibration data are not available. Ring-porous taxa are widely distributed and represent an important component of the regional water budgets of many temperate regions. Our results are important for evaluating plant water use of ring-porous tree species with thermal dissipation probes at multiple spatial scales.

Bush, S. E.; Hultine, K. R.; Ehleringer, J. R.



Tree Species of the Central Amazon Affects Natural Abundance of Nitrous Oxide Isotopes  

NASA Astrophysics Data System (ADS)

The use of stable isotopes of N and O in N2O has been proposed as a way to better constrain the global budget of atmospheric N2O and to better understand relative contribution of the main microbial processes (nitrification and denitrification) responsible for N2O formation in soil. This study examined the effects of tree species used in plantation systems of the Brazilian Amazon in comparison to natural and secondary forests on the isotopic composition of N{2}O emitted from the soil. We also compared the effects of tree species with those of soil moisture, as we expected the latter to be the main factor regulating the proportion of nitrifier and denitrifier derived N2O and, consequently, isotopic signatures of N2O. To our knowledge, this is the first study to show that tree species significantly affect the 15N composition of nitrous oxide, likely due to tree-mediated changes in microbial communities. However, we found no evidence that varying contributions of nitrification and denitrification to N2O flux contributed to variation in the 15N composition of N2O. In our study, all N2O was likely produced by denitrification. We suspect that the differences in 15N observed were due to effect of nitrate immobilization on isotopes of N in nitrate, the substrate for denitrification. However, this explanation needs further verification. While tree species did affect the 15N composition of N2O, they did not affect the rate of N2O emission. We conclude that tree species contribute to a large isotopic variation in N2O observed in a range tropical forest soils. We found that soil water affects both 15N and 18O in N2O, with wetter soils producing N2O depleted in 15N and 18O. This is likely caused by increased activity of denitrification and/or decrease nitrate immobilization in case of 15N, and both by denitrification and by direct exchange of 18O-H2O and N2O with NO3-.

Menyailo, O. V.; Lehmann, J.; Gebauer, G.; Hungate, B. A.; Zech, W.



Strong Neutral Spatial Effects Shape Tree Species Distributions across Life Stages at Multiple Scales  

PubMed Central

Traditionally, ecologists use lattice (regional summary) count data to simulate tree species distributions to explore species coexistence. However, no previous study has explicitly compared the difference between using lattice count and basal area data and analyzed species distributions at both individual species and community levels while simultaneously considering the combined scenarios of life stage and scale. In this study, we hypothesized that basal area data are more closely related to environmental variables than are count data because of strong environmental filtering effects. We also address the contribution of niche and the neutral (i.e., solely dependent on distance) factors to species distributions. Specifically, we separately modeled count data and basal area data while considering life stage and scale effects at the two levels with simultaneous autoregressive models and variation partitioning. A principal coordinates of neighbor matrix (PCNM) was used to model neutral spatial effects at the community level. The explained variations of species distribution data did not differ significantly between the two types of data at either the individual species level or the community level, indicating that the two types of data can be used nearly identically to model species distributions. Neutral spatial effects represented by spatial autoregressive parameters and the PCNM eigenfunctions drove species distributions on multiple scales, different life stages and individual species and community levels in this plot. We concluded that strong neutral spatial effects are the principal mechanisms underlying the species distributions and thus shape biodiversity spatial patterns.

Hu, Yue-Hua; Lan, Guo-Yu; Sha, Li-Qing; Cao, Min; Tang, Yong; Li, Yi-De; Xu, Da-Ping



Effect of chlorine pollution on three fruit tree species at Ranoli near Baroda, India.  


This paper describes the effect of chlorine pollution from an alkalies and chemical plant at Ranoli, near Baroda, on three tropical fruit tree species-Mangifera indica L. (mango) Manilkara hexandra Dubard. (rayan) and Syzygium cumini Skeels (Jamun). As compared to controls growing in a less polluted area, trees growing close to the plant showed reduced mean leaf area, a higher percentage of leaf area damaged, a reduction in fruit yield, chlorophyll pigments, protein and carbohydrate content, and higher accumulation of chloride in the foliar tissues. The accumulation of pollutaant, chloride, in the foliar tissues was very high in mango and jamun. Based on the degree of damage to the plants, the species studied were arranged in decreasing order of their sensitivity to chlorine pollution-mango, jamun and rayan. PMID:15092455

Vijayan, R; Bedi, S J



Temporal and spatial variability in insect grazing of the canopies of five Australian rainforest tree species  

Microsoft Academic Search

Herbivory was measured monthly for 2 years on leaves of permanently rnarkecl replicate branches in the canopies of five Australian rainforesr tree species. Variability in insect grazing activities was evident with respect to several factors: I. lec~f age - young letrvc,., werc prqfc~rretl olbrr older Icc~f tiss~~e; 2. height - lectves c.loscr to grourltl Ic~,el rvere more heirr'il~ prtc;etl:




Potential of some Neotropical Albizia species as shade trees whenreplanting cacao in Ghana  

Microsoft Academic Search

The Cocoa Research Institute of Ghana has embarked on studies to support the replanting of cacao (Theobroma cacao L) in areas, which previously carried the crop but are now degraded. A key component of the studies is to identify fast growing\\u000a tree species capable of ameliorating degraded soils and ultimately providing suitable shade for cacao. A screening trial involving\\u000a ten

G. J. Anim-Kwapong



The water relations of two evergreen tree species in a karst savanna  

Microsoft Academic Search

The ecohydrology of karst has not received much attention, despite the disproportionally large contribution of karst aquifers\\u000a to freshwater supplies. Karst savannas, like many savannas elsewhere, are encroached by woody plants, with possibly negative\\u000a consequences on aquifer recharge. However, the role of savanna tree species in hydrological processes remains unclear, not\\u000a least because the location and water absorption zones of

Susanne Schwinning



In vitro propagation of Syzygium travancoricum Gamble – an endangered tree species  

Microsoft Academic Search

Rapid multiplication in Syzygium travancoricum, an endangered tree species was achieved from nodal explants on Murashige and Skoog's (MS) medium supplemented with Woody Plant Medium (WPM) micronutrients and plant growth regulators. Multiple shoot induction from young 1–2-year-old seedlings was observed on basal medium supplemented with 17.7 µM benzyladenine and 1.3 µM a-naphthalene acetic acid. A high number of multiple shoots

Ajith Anand; C. Srinivasa Rao; P. Balakrishna



Tree species and wood ash affect soil in Michigan’s Upper Peninsula  

Microsoft Academic Search

Tree species and wood ash application in plantations of short-rotation woody crops (SRWC) may have important effects on the\\u000a soil productive capacity through their influence on soil organic matter (SOM) and exchangeable cations. An experiment was\\u000a conducted to assess changes in soil C and N contents and pH within the 0–50 cm depth, and exchangeable cation (Ca2+, Mg2+, K+, and Na+)

Fabio Sartori; Rattan Lal; Michael H. Ebinger; Raymond O. Miller



Amino acid uptake by temperate tree species characteristic of low- and high-fertility habitats  

Microsoft Academic Search

The relationship between inorganic nitrogen (N) cycling and plant productivity is well established. However, recent research\\u000a has demonstrated the ability of plants to take up low molecular weight organic N compounds (i.e., amino acids) at rates that\\u000a often rival those of inorganic N forms. In this study, we hypothesize that temperate forest tree species characteristic of\\u000a low-fertility habitats will prefer

Emily E. ScottDavid; David E. Rothstein


Atmospheric change alters foliar quality of host trees and performance of two outbreak insect species.  


This study examined the independent and interactive effects of elevated carbon dioxide (CO(2)) and ozone (O(3)) on the foliar quality of two deciduous trees species and the performance of two outbreak herbivore species. Trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) were grown at the Aspen FACE research site in northern Wisconsin, USA, under four combinations of ambient and elevated CO(2) and O(3). We measured the effects of elevated CO(2) and O(3) on aspen and birch phytochemistry and on gypsy moth (Lymantria dispar) and forest tent caterpillar (Malacosoma disstria) performance. Elevated CO(2) nominally affected foliar quality for both tree species. Elevated O(3) negatively affected aspen foliar quality, but only marginally influenced birch foliar quality. Elevated CO(2) slightly improved herbivore performance, while elevated O(3) decreased herbivore performance, and both responses were stronger on aspen than birch. Interestingly, elevated CO(2) largely offset decreased herbivore performance under elevated O(3). Nitrogen, lignin, and C:N were identified as having strong influences on herbivore performance when larvae were fed aspen, but no significant relationships were observed for insects fed birch. Our results support the notion that herbivore performance can be affected by atmospheric change through altered foliar quality, but how herbivores will respond will depend on interactions among CO(2), O(3), and tree species. An emergent finding from this study is that tree age and longevity of exposure to pollutants may influence the effects of elevated CO(2) and O(3) on plant-herbivore interactions, highlighting the need to continue long-term atmospheric change research. PMID:21971584

Couture, John J; Meehan, Timothy D; Lindroth, Richard L



Soil fertility enhancement by planted tree-fallow species in the humid lowlands of Cameroon  

Microsoft Academic Search

Four shrub\\/tree species, Alchornea cordifolia, Pennisetum purpureum, Chromolaena odorata, and Calliandra calothyrsus were\\u000a evaluated for their potential contribution to soil fertility restoration after two years fallow. Standing biomass, root distribution,\\u000a nutrient content in the biomass, decomposition and nutrient release patterns, and association with mycorrhizae were the evaluation\\u000a parameters. Alchornea and Pennisetum produced thehighest above-ground biomass, 66 t and 54 t\\/ha

J. Kanmegne; B. Duguma; J. Henrot; N. O. Isirimah



Contrasting effects of ozone under different water supplies in two Mediterranean tree species  

Microsoft Academic Search

The effects of ozone (O3) exposure under different water availabilities were studied in two Mediterranean tree species: Quercus ilex and Ceratonia siliqua. Plants were exposed to different O3 concentrations in open top chambers (charcoal-filtered air (CF), non-filtered air (NF)) and non-filtered air plus 40ppbv of O3 ((7:00–17:00 solar time) (NF+)) during 2 years, and to different water regimes (IR, sample

Àngela Ribas; Josep Peñuelas; Susana Elvira; Benjamín S. Gimeno



The All-Species Living Tree project: A 16S rRNA-based phylogenetic tree of all sequenced type strains  

Microsoft Academic Search

The signing authors together with the journal Systematic and Applied Microbiology (SAM) have started an ambitious project that has been conceived to provide a useful tool especially for the scientific microbial taxonomist community. The aim of what we have called “The All-Species Living Tree” is to reconstruct a single 16S rRNA tree harboring all sequenced type strains of the hitherto

Pablo Yarza; Michael Richter; Jörg Peplies; Jean Euzeby; Rudolf Amann; Karl-Heinz Schleifer; Wolfgang Ludwig; Frank Oliver Glöckner; Ramon Rosselló-Móra



Altered resource availability and the population dynamics of tree species in Amazonian secondary forests.  


Despite research demonstrating that water and nutrient availability exert strong effects on multiple ecosystem processes in tropical forests, little is known about the effect of these factors on the demography and population dynamics of tropical trees. Over the course of 5 years, we monitored two common Amazonian secondary forest species-Lacistema pubescens and Myrcia sylvatica-in dry-season irrigation, litter-removal and control plots. We then evaluated the effects of altered water and nutrient availability on population demography and dynamics using matrix models and life table response experiments. Our results show that despite prolonged experimental manipulation of water and nutrient availability, there were nearly no consistent and unidirectional treatment effects on the demography of either species. The patterns and significance of observed treatment effects were largely dependent on cross-year variability not related to rainfall patterns, and disappeared once we pooled data across years. Furthermore, most of these transient treatment effects had little effect on population growth rates. Our results suggest that despite major experimental manipulations of water and nutrient availability-factors considered critical to the ecology of tropical pioneer tree species-autogenic light limitation appears to be the primary regulator of tree demography at early/mid successional stages. Indeed, the effects of light availability may completely override those of other factors thought to influence the successional development of Amazonian secondary forests. PMID:19997929

Fortini, Lucas Berio; Bruna, Emilio M; Zarin, Daniel J; Vasconcelos, Steel S; Miranda, Izildinha S



Structural and chemical characterization of hardwood from tree species with applications as bioenergy feedstocks.  


Eucalypt species are a group of flowering trees widely used in pulp production for paper manufacture. For several decades, the wood pulp industry has focused research and development efforts on improving yields, growth rates and pulp quality through breeding and the genetic improvement of key tree species. Recently, this focus has shifted from the production of high quality pulps to the investigation of the use of eucalypts as feedstocks for biofuel production. Here the structure and chemical composition of the heartwood and sapwood of Eucalyptus dunnii, E. globulus, E. pillularis, E. urophylla, an E. urophylla-E. grandis cross, Corymbia citriodora ssp. variegata, and Acacia mangium were compared using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD) and biochemical composition analysis. Some trends relating to these compositions were also identified by Fourier transform near infrared (FT-NIR) spectroscopy. These results will serve as a foundation for a more comprehensive database of wood properties that will help develop criteria for the selection of tree species for use as biorefinery feedstocks. PMID:23300786

Cetinkol, Özgül Persil; Smith-Moritz, Andreia M; Cheng, Gang; Lao, Jeemeng; George, Anthe; Hong, Kunlun; Henry, Robert; Simmons, Blake A; Heazlewood, Joshua L; Holmes, Bradley M



Soil Terpene Emissions in a Subalpine Coniferous Forest: Tree Species, Soil Temperature and Moisture Effects  

NASA Astrophysics Data System (ADS)

Some studies have shown soils can contribute significantly to the canopy level fluxes of volatile organic compounds (VOCs) in some ecosystem types during some seasons. Yet patterns of soil VOCs fluxes as well as controls are poorly known and so the potential importance of soil VOCs emissions on the total global BVOCs emissions from terrestrial sources remains unclear. We measured soil terpene emission at a high-elevation, mixed conifer, subalpine forest site at the Niwot Ridge Ameriflux Site in Colorado. Given the important role of terpenes on the formation of secondary organic aerosols and given that high amounts of terpenes are produced and stored in coniferous tissues (e. g. roots and litter) we focused only on these compounds in this study. The objectives were to quantify soil terpene flux and its contribution to the canopy level flux and to identify environmental variables controlling soil terpene emissions in this forest, such as tree species, tree species density, total soil organic matter content, soil temperature and soil moisture . During the summer 2009 (August), soil terpene emission rates were measured in soil chambers regularly distributed in a 200 x 200 m area around the flux tower. To test the effect of the tree species on soil emissions, additional chambers were placed on relative pure stands of each one of the representative species. The average total monoterterpene emission rate during August 2009 was 21 ?g C m-2 h-1. These emissions represent 9% of the total terpene canopy fluxes reported in this forest during the same period on previous summers (August 2007, 238 ?g C m-2 h-1). The range of monoterpene emission was found to be high; emissions went up to 368 ?g C m-2 h-1 under specific conditions. Total sesquiterpene emissions were much lower than monoterpenes (0.04 ± 0.01 ?g C m-2 h-1). Due to the high variability found, no clear effect of the space distribution was identified. However, soil terpene emissions were significantly affected by the tree species (higher emissions under Pine > Spruce > Fir) and consequently tree species density was found to explain better soil terpene emissions variability. When data from all soil emission measurements were pooled and regressed against total soil organic matter content, soil temperature or soil moisture no significant linear relationship was found. These results show soil terpene emissions can be significant compared to canopy level fluxes during some periods of the year and that could be altered in response to vegetation changes. The fact that no significant linear relationship was found between soil terpene emissions and soil temperature and moisture suggest other possible factors may be controlling soil emission in this ecosystem, such as roots or microbial activity.

Asensio, D.; Duhl, T.; Greenberg, J.; Guenther, A. B.; Monson, R. K.



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

NASA Astrophysics Data System (ADS)

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

Chauhan, S. K.; Soni, R.



Identification of endangered or threatened Costa Rican tree species by wood anatomy and fluorescence activity.  


A total of 45 native Costa Rican tree species are threatened or in danger of extinction, but the Convention on International Trade Endangered Species (CITES) includes only eight of these in its Appendices. However, the identification of other species based on their wood anatomy is limited. The present study objective was to describe and to compare wood anatomy and fluorescence activity in some endangered or threatened species of Costa Rica. A total of 45 (22 endangered and 23 threatened with extinction) wood samples of these species, from the xylaria of the Instituto Tecnológico de Costa Rica and the Forest Products Laboratory in Madison, Wisconsin, were examined. Surface fluorescence was positive in eight species, water extract fluorescence was positive in six species and ethanol extract fluorescence was positive in 24 species. Almost all species were diffuse porous except for occasional (Cedrela odorata, C. fissilis, Cordia gerascanthus) or regular (C. salvadorensis and C. tonduzii) semi-ring porosity. A dendritic vessel arrangement was found in Sideroxylon capari, and pores were solitary in Guaiacum sanctum and Vantanea barbourii. Vessel element length was shortest in Guaiacum sanctum and longest in Humiriastrum guianensis, Minquartia guianensis and Vantanea barbourii. Finally, anatomical information and fluorescence activity were utilized to construct an identification key of species, in which fluorescence is a feature used in identification. PMID:24027913

Moya, Róger; Wiemann, Michael C; Olivares, Carlos



Interspecific variation in xylem vulnerability to cavitation among tropical tree and shrub species.  


In tropical moist forests, seasonal drought limits plant survival, productivity and diversity. Drought-tolerance mechanisms of tropical species should reflect the maximum seasonal water deficits experienced in a particular habitat. We investigated stem xylem vulnerability to cavitation in nine tropical species with different life histories and habitat associations. Stem xylem vulnerability was scored as the xylem water potential causing 50 and 75% loss of hydraulic conductivity (P50 and P75, respectively). Four shade-tolerant shrubs ranged from moderately resistant (P50=-1.9 MPa for Ouratea lucens Kunth. Engl.) to highly resistant to cavitation (P50=-4.1 MPa for Psychotria horizontalis Sw.), with shallow-rooted species being the most resistant. Among the tree species, those characteristic of waterlogged soils, Carapa guianensis Aubl., Prioria copaifera Griseb. and Ficus citrifolia Mill., were the most vulnerable to cavitation (P50=-0.8 to -1.6 MPa). The wet-season, deciduous tree, Cordia alliodora (Ruiz and Pav.) Oken., had resistant xylem (P50=-3.2 MPa), whereas the dry-season, deciduous tree, Bursera simaruba (L.) Sarg. was among the most vulnerable to cavitation (P50=-0.8 MPa) of the species studied. For eight out of the nine study species, previously reported minimum seasonal leaf water potentials measured in the field during periods of drought correlated with our P50 and P75 values. Rooting depth, deciduousness, soil type and growth habit might also contribute to desiccation tolerance. Our results support the functional dependence of drought tolerance on xylem resistance to cavitation. PMID:16137941

Lopez, Omar R; Kursar, Thomas A; Cochard, Hervé; Tyree, Melvin T



Tree species yielding edible fruit in the coffee-based homegardens of Kerala, India: their diversity, uses and management  

Microsoft Academic Search

The homegardens of Kerala are known for the high diversity of their species in both cultivated and managed plant communities,\\u000a with fruit trees as one of the more important components. A study was conducted to quantify the density and diversity of both\\u000a cultivated and non-crop trees that yielded edible fruit (hereafter, fruit trees) in coffee-based homegardens of the State.\\u000a Among

U. M. Chandrashekara



Contribution of tree species to the biodiversity of a 1ha Old World rainforest in Brunei, Borneo  

Microsoft Academic Search

Tree biodiversity data is presented for a 1-ha permanent study plot on a low slope position of the Kuala Belalong valley in Temburong District, Brunei, Borneo. This is the first study in the region to document the tree flora of a low slope. All trees =5?cm at 1.3?m were mapped, measurements of dbh and height taken, and identified to species

Andrew Small; Tara G. Martin; Roger L. Kitching; Khoon Meng Wong



Does flood tolerance explain tree species distribution in tropical seasonally flooded habitats?  


In the tropics, seasonally flooded forests (SFF) harbor fewer tree species than terra firme (i.e. non-flooded) forests. The low species diversity of tropical flooded forests has been ascribed to the paucity of species with adaptations to tolerate flooding. To test the hypothesis that flooding is the only factor restricting most species from SFF, we compared plant morphological and physiological responses to flooding in 2-month old seedlings of 6 species common to SFF and 12 species common to terra firme forests. Although flooding impaired growth, total biomass, maximum root length and stomatal conductance in most species, responses varied greatly and were species-specific. For example, after 90 days, flooding reduced leaf area growth by 10-50% in all species, except in Tabebuia, a common species from non-flooded habitats. Similarly, flooding had a 5-45% negative effect on total biomass for all species, except in 1 SFF and 1 terra firme species both of which had more biomass under flooding. A principal component analysis, using the above responses to flooding, provided no evidence that SFF and terra firme species differed in their responses to flooding. Flooding also caused reductions in root growth for most species. Rooting depth and root: shoot ratios were significantly less affected by flooding in SFF than in terra firme species. Although flood tolerance is critical for survival in flooded habitats, we hypothesize that responses to post-flooding events such as drought might be equally important in seasonal habitats. Therefore, we suggest that the ability to grow roots under anoxia might be critical in predicting success in inundated habitats that also experience a strong dry season. PMID:12743794

Lopez, Omar R; Kursar, Thomas A



The Influence of Recent Climate Change on Tree Height Growth Differs with Species and Spatial Environment  

PubMed Central

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

Messaoud, Yassine; Chen, Han Y. H.



Mapping of forest species and tree density using new Earth observation sensors for wildfire applications  

NASA Astrophysics Data System (ADS)

The success of any decision support system for managing wildfires lies on its ability to simulate fire evolution. Therefore, accurate information on the natural fuel material in any area of interest is necessary. The present study aims to provide methodological tools to explore in depth the potential of new Earth Observation data for horizontal mapping of vegetated areas. Two approaches are mainly described. The first one deals with the classification of ASTER visible, near- and short-wave infrared images in a detailed nomenclature including both different species and tree densities. This is important for wildfire studies since the same vegetation classes may represent completely different risk ignition levels depending on their morphological characteristics (i.e., trees height and density). The improvement of class separability using hyperspectral images acquired by Hyperion is also investigated. The second approach refers to a pattern recognition software tool for single tree counting using a very high spatial resolution image acquired by IKONOS-2 satellite. According to this approach, the regions dense in plants are identified by applying a suitable thresholding on the image. The resulted regions are further processed in order to estimate the number and location of single trees based on a pre-specified crown size per stratified zone. The outcome of the latter approach may provide direct evidence of tree density relating to ground biomass. Finally, the two approaches are used in a complementary manner to explore the possibilities offered by new sensor technology to override past limitations in species and fuel classification due to inadequate spectral/spatial resolution. The pilot application area is Mount. Pendeli and the east side of Mount. Parnitha, in the prefecture of Attiki, Greece.

Keramitsoglou, Iphigenia; Kontoes, Charalambos; Koutroumbas, Konstantinos; Sykioti, Olga; Sifakis, Nicolaos



Fruit production in three masting tree species does not rely on stored carbon reserves.  


Fruiting is typically considered to massively burden the seasonal carbon budget of trees. The cost of reproduction has therefore been suggested as a proximate factor explaining observed mast-fruiting patterns. Here, we used a large-scale, continuous (13)C labeling of mature, deciduous trees in a temperate Swiss forest to investigate to what extent fruit formation in three species with masting reproduction behavior (Carpinus betulus, Fagus sylvatica, Quercus petraea) relies on the import of stored carbon reserves. Using a free-air CO2 enrichment system, we exposed trees to (13)C-depleted CO2 during 8 consecutive years. By the end of this experiment, carbon reserve pools had significantly lower ?(13)C values compared to control trees. ?(13)C analysis of new biomass during the first season after termination of the CO2 enrichment allowed us to distinguish the sources of built-in carbon (old carbon reserves vs. current assimilates). Flowers and expanding leaves carried a significant (13)C label from old carbon stores. In contrast, fruits and vegetative infructescence tissues were exclusively produced from current, unlabeled photoassimilates in all three species, including F. sylvatica, which had a strong masting season. Analyses of ?(13)C in purified starch from xylem of fruit-bearing shoots revealed a complete turn-over of starch during the season, likely due to its usage for bud break. This study is the first to directly demonstrate that fruiting is independent from old carbon reserves in masting trees, with significant implications for mechanistic models that explain mast seeding. PMID:23306421

Hoch, Günter; Siegwolf, Rolf T W; Keel, Sonja G; Körner, Christian; Han, Qingmin



On the functional role of tree species in two forest ecosystems  

NASA Astrophysics Data System (ADS)

Ecosystems can be characterized in different ways depending on the point of view or the scientific background. Summarizing these views, one can describe ecosystems by their structure and metabolism. The species composition is part of the ecosystem structure. Moreover, ecosystem structures are detailed by biomass or soil and canopy architecture. Ecosystem metabolism represents the functional side. It can be described by primary production, nutrient retention, or control and use of water resources. Structure and function are connected. The biomass that is produced by the ecosystem metabolism is used to construct the ecosystem structure, which vice versa the structure controls the efficiency of the ecosystem metabolism. One hypothesis is that ecosystems with many species provide a more efficient metabolism than ecosystems with fewer species. We tested this hypothesis by using two ecosystems functional parameters in several deciduous forest ecosystems. The first example are possible relations between canopy carbon uptake capacity (FP,max) as measured with the eddy covariance technique (ecosystem metabolism) and LAI as well as spatial and temporal variability of leaf traits (ecosystem structure). We investigated leaf traits of four tree species in a mixed deciduous forest in northern Germany in search for an explanation for the differences in canopy photosynthetic capacity between different forest sectors consisting of different species and species numbers (Quercus robur + Fagus sylvatica, Fraxinus excelsior + Alnus glutinosa, pure Fagus sylvatica). We identified leaf traits that were adjusted to the canopy light profile in species-specific ways, and for these traits the plasticity indices were calculated. Canopy photosynthetic capacity did neither correlate with leaf area index (LAI) alone nor with canopy plasticity indices which were almost similar between the three sectors although it differed at the species level. It is suggested that the spatial variability of FP,max in deciduous forests can be explained by a combined effect of LAI and some species-specific reference leaf traits, rather than by the plasticity index or by pure LAI. In a second study we compared a mixed canopy of Fagus sylvatica and Fraxinus excelsior to a pure Fagus sylvatica stand during a drought period in summer 2006. Leaf gas exchange measurements suggested that beech trees responded faster and stronger to soil drought and changed stomatal sensitivity to leaf to air water vapour pressure deficit, while ash trees remained more progressive. Scaling these results in a modelling approach resulted in an lower impact of drought in a two-species canopy than in a beech monoculture and an increase of the Fraxinus contribution to total ecosystem carbon uptake. Both results support the hypothesis that multi-species canopies may buffer unfavourable environmental constraints and increase efficiency in the use of resources.

Kutsch, Werner Leo; Herbst, Mathias; Liu, Chunjiang



Effect of distance, aggregation, and habitat on levels of seed predation for two mammal — dispersed neotropical rain forest tree species  

Microsoft Academic Search

The effect of seed aggregation and distance from conspecific trees on seed predation was experimentally examined for two neotropical tree species, Macoubea guianensis (Apocynaceae) and Pouteria sp. (Sapotaceae) in a lowland tropical rain forest in northeastern Peru. Results of these experiments are discussed in the context of the Janzen-Connell model (Janzen 1970; Connell 1971), which predicts decreased seed survival near

Evan Notman; David L. Gorchov; Fernando Cornejo




Technology Transfer Automated Retrieval System (TEKTRAN)

In long-term experimental plantations at La Selva Biological Station, Costa Rica, we investigated the effects of six tree species on soil properties. In 1988, trees were established on degraded pasture in a randomized complete block design. Soil organic Carbon (SOC) differed significantly among spec...


Diameter increment patterns among 106 tree species in a logged and silviculturally treated Costa Rican rain forest  

Microsoft Academic Search

Studies of growth rates of trees in managed neotropical forests have rarely employed complete botanical identification of all species, while published information for Central American lowland rain forests largely concerns forests free of recent disturbance. We studied diameter increments of trees in a managed Costa Rican rain forest. The Pentaclethra macroloba-dominated forest was located on low hills with Ultisols in

Bryan Finegan; Marlen Camacho; Nelson Zamora



Wood carbon content of tree species in Eastern China: Interspecific variability and the importance of the volatile fraction  

Microsoft Academic Search

Data on the mass density and carbon content of tree organs, and in particular stem wood, are essential for accurate assessments of forest carbon sequestration. However most available data, including that for East Asia, has neglected the volatile C fraction. Wood samples were collected and assayed for C content from 14 native tree species in Jilin Province, NE China. C

S. C. Thomas; G. Malczewski



Elevational adaptation and plasticity in seedling phenology of temperate deciduous tree species.  


Phenological events, such as the initiation and the end of seasonal growth, are thought to be under strong evolutionary control because of their influence on tree fitness. Although numerous studies highlighted genetic differentiation in phenology among populations from contrasting climates, it remains unclear whether local adaptation could restrict phenological plasticity in response to current warming. Seedling populations of seven deciduous tree species from high and low elevations in the Swiss Alps were investigated in eight common gardens located along two elevational gradients from 400 to 1,700 m. We addressed the following questions: are there genetic differentiations in phenology between populations from low and high elevations, and are populations from the upper elevational limit of a species' distribution able to respond to increasing temperature to the same extent as low-elevation populations? Genetic variation of leaf unfolding date between seedlings from low and high populations was detected in six out of seven tree species. Except for beech, populations from high elevations tended to flush later than populations from low elevations, emphasizing that phenology is likely to be under evolutionary pressure. Furthermore, seedlings from high elevation exhibited lower phenological plasticity to temperature than low-elevation provenances. This difference in phenological plasticity may reflect the opposing selective forces involved (i.e. a trade-off between maximizing growing season length and avoiding frost damages). Nevertheless, environmental effects were much stronger than genetic effects, suggesting a high phenological plasticity to enable tree populations to track ongoing climate change, which includes the risk of tracking unusually warm springs followed by frost. PMID:23306445

Vitasse, Yann; Hoch, Günter; Randin, Christophe F; Lenz, Armando; Kollas, Chris; Scheepens, J F; Körner, Christian



Co-occurring species differ in tree-ring delta(18)O trends.  


The stable oxygen isotope ratio (delta(18)O) of tree-ring cellulose is jointly determined by the delta(18)O of xylem water, the delta(18)O of atmospheric water vapor, the humidity of the atmosphere and perhaps by species-specific differences in leaf structure and function. Atmospheric humidity and the delta(18)O of water vapor vary seasonally and annually, but if the canopy atmosphere is well mixed, atmospheric characteristics should be uniform among co-occurring trees. In contrast, xylem water delta(18)O is determined by the delta(18)O of water being drawn from the soil, which varies with depth. If co-occurring trees draw water from different soil depths, this soil-water delta(18)O signal would be manifest as differences in delta(18)O among the trees. We examined the variation in tree ring delta(18)O, over eight decades during the 20th Century, among three species co-occurring in natural forest stands of the northern Rocky Mountains in the USA. We sampled 10 Douglas-firs (Pseudotsuga menziesii (Mirb.) Franco var. glauca), 10 ponderosa pines (Pinus ponderosa Laws.) and seven western white pines (Pinus monticola Dougl.). As expected, variation in atmospheric conditions was recorded in the delta(18)O of the cellulose produced in a given year, but observed climatic correlations with delta(18)O were weak. Significant correlations with June climate data included: daily maximum temperature (r = 0.29), daily minimum temperature (r = -0.25), mean temperature (r = 0.20), mean daily precipitation (r = -0.54), vapor pressure deficit (r = 0.32) and solar radiation (r = 0.44). Lagged effects were observed in Douglas-fir and western white pine. In these species, the delta(18)O of a given annual ring was correlated with the delta(18)O of the previous ring. Ponderosa pine showed no significant autocorrelation. Although the species means were correlated among years (r = 0.67 to 0.76), ponderosa pine was consistently enriched in delta(18)O relative to the other species; differences were close to 2 per thousand and they are steadily increasing. Relative to the mean for the three species, ponderosa pine is becoming steadily more enriched (-1.0 per thousand). In contrast, Douglas-fir is being steadily depleted and western pine is intermediate, with an enrichment of 0.5 per thousand. Because all trees were exposed to the same atmospheric conditions, the differences in delta(18)O observed between species are likely due either to differences in the depth of water extraction or leaf function. If the former, presumably ponderosa pine has steadily taken up more water from near the soil surface and Douglas-fir has shifted uptake to a greater depth. If the latter, we suggest the pronounced changes in leaf-water delta(18)O are a result of changes in leaf structure and function with tree size and age. PMID:16651255

Marshall, John D; Monserud, Robert A



Wood density and its radial variation in six canopy tree species differing in shade-tolerance in western Thailand  

PubMed Central

Background and Aims Wood density is a key variable for understanding life history strategies in tropical trees. Differences in wood density and its radial variation were related to the shade-tolerance of six canopy tree species in seasonally dry tropical forest in Thailand. In addition, using tree ring measurements, the influence of tree size, age and annual increment on radial density gradients was analysed. Methods Wood density was determined from tree cores using X-ray densitometry. X-ray films were digitized and images were measured, resulting in a continuous density profile for each sample. Mixed models were then developed to analyse differences in average wood density and in radial gradients in density among the six tree species, as well as the effects of tree age, size and annual increment on radial increases in Melia azedarach. Key Results Average wood density generally reflected differences in shade-tolerance, varying by nearly a factor of two. Radial gradients occurred in all species, ranging from an increase of (approx. 70%) in the shade-intolerant Melia azedarach to a decrease of approx. 13% in the shade-tolerant Neolitsea obtusifolia, but the slopes of radial gradients were generally unrelated to shade-tolerance. For Melia azedarach, radial increases were most-parsimoniously explained by log-transformed tree age and annual increment rather than by tree size. Conclusions The results indicate that average wood density generally reflects differences in shade-tolerance in seasonally dry tropical forests; however, inferences based on wood density alone are potentially misleading for species with complex life histories. In addition, the findings suggest that a ‘whole-tree’ view of life history and biomechanics is important for understanding patterns of radial variation in wood density. Finally, accounting for wood density gradients is likely to improve the accuracy of estimates of stem biomass and carbon in tropical trees.

Nock, Charles A.; Geihofer, Daniela; Grabner, Michael; Baker, Patrick J.; Bunyavejchewin, Sarayudh; Hietz, Peter



[Time lag characteristics of stem sap flow of common tree species during their growth season in Beijing downtown].  


From April to September in 2008, the stem sap flow velocity (Js) of several common tree species (Ginkgo biloba, Aesculus chinensis, Magnolia denudata, Robinia pseudoacacia, Pinus tabulaeformis and Cedrus deodara) in Beijing was measured by thermal dissipation method. Crosscorrelation analysis was used to estimate the time lag between the stem sap flow and the driving factors of canopy transpiration among the tree species. The Js of the six tree species was significantly correlated with the total radiation (Rs) and vapor pressure deficit (D), and the Js was lagged behind Rs but ahead of D. The maximum correlation coefficient of Js with Rs (0.74-0.93) was often higher than that of Js with D (0.57-0.79), indicating that the diurnal Js was more dependent on Rs than on D. The sampled tree species except P. tabulaeformis had a shorter time lag of Js with Rs (10-70 min) than with D (47-130 min), and there existed significant differences among R. pseudoacacia, P. tabulaeformis, and C. deodara. The time lag between the Js and the driving factors of canopy transpiration was mainly correlated with the tree features (DBH, tree height, canopy area, and sapwood area) and the nocturnal water recharge, regardless of tree species. PMID:20030130

Wang, Hua; Ouyang, Zhi-yun; Zheng, Hua; Wang, Xiao-ke; Ni, Yong-ming; Ren, Yu-fen



Contrasts in growth and water sources in co-occurring Mediterranean riparian tree species: Evidence from tree ring isotopes and dendrochronology  

NASA Astrophysics Data System (ADS)

Riparian trees have growth responses to varying water sources that are more subtle than those of their upland counterparts, but differences in water use between co-occurring riparian species are not easily discerned by conventional dendrochronology. While tree ring isotopes have been developed as a useful tool for understanding past climate (temperature and precipitation) at the growth limits for particular species, relatively little research has investigated responses in tree growth in water-rich environments, where co-occurring tree species may express differential adaptation to water availability and shifting water sources. Better understanding of such subtle adaptations will improve predictions of the response of lowland riparian forests to climate changes that manifest as shifts in: regional ground water tables; the spatial/temporal distribution of precipitation; or volumes and timing of streamflow. We use an approach that combines dendrochronology and tree ring isotopes (?18O) to discern the relationships between tree growth and water sources for two contrasting, co-occurring Mediterranean riparian species-- Fraxinus excelsior and Populus nigra. We developed growth time series via two methods (one de-trended for climate) and extracted alpha-cellulose from tree rings to assess relative responses to water stress via ?18O, and we analyzed these data alongside streamflow and precipitation data for the Ain River basin in France. We find that both species exhibit decreased growth during drought years, but F. excelsior demonstrates more consistent annual growth than P. nigra. In contrast, oxygen isotopic values in P. nigra have low interannual variability compared with ?18O in F. excelsior. These differences suggest contrasting patterns of water use by these co-occurring species, wherein F. excelsior functions as an opportunist, scavenging water from the vadose zone where and when it cannot access groundwater. In contrast, the P. nigra demonstrates consistent groundwater usage (consistent with its moniker-obligate phreatophyte) and tends to struggle in drought years. These observations are consistent with ancillary data on rooting depths which show that F. excelsior maintains its roots above the gravel layer, where it can extract soil water from precipitation or overbank flooding. In contrast, P. nigra roots deeply into the phreatic zone without maintaining significant vadose zone roots, and is therefore less adaptable to rapid declines in the water table. These factors suggest, in contrast to prior work, that poplars may be more sensitive to drought than ash trees. Such dynamics in water use between such co-occurring, yet contrasting riparian trees within a riparian floodplain may indicate the response in succession and stand composition to climate changes or major anthropogenic impacts.

Singer, M. B.; Dufour, S.; Stella, J. C.; Piégay, H.; Johnstone, L.; Wilson, R.



Interactions of gap size and herbivory on establishment, growth and survival of three species of neotropical pioneer trees  

Microsoft Academic Search

Summary 1 The difference in gap size requirements observed for neotropical pioneer species is a classic example of habitat partitioning among tropical tree species. Previous research has shown that the three species Miconia argentea , Cecropia insignis and Trema micrantha differ in the minimum gap size that they occupy as adult plants in semi-deciduous tropical forest in Panamá. Here we

Timothy R. H. Pearson; David F. R. P. Burslem; Rachel E. Goeriz; James W. Dalling



Light environment and tree development of young Acacia melanoxylon in mixed-species regrowth forest, Tasmania, Australia  

Microsoft Academic Search

Blackwood (Acacia melanoxylon R. Br.) is a valuable leguminous cabinetwood species which is commonly found as a canopy or subcanopy tree in a broad range of mixed-species moist forests on tablelands and coastal escarpments in eastern Australia. This paper reports on the competitive light environment of a commercially valuable multi-species regrowth forest in NW Tasmania, in order to define some

G. L. Unwin; S. M. Jennings; M. A. Hunt



Differential responses of antioxidant enzymes in pioneer and late-successional tropical tree species grown under sun and shade conditions  

Microsoft Academic Search

To investigate the ability of pioneer and late-successional species to adapt to a strong light environment in a reforestation area, we examined the activities of antioxidant enzymes in relation to photosystem II, chlorophyll a fluorescence and photosynthetic pigment concentration for eight tropical tree species grown under 100% (sun) and 10% (shade) sunlight irradiation. The pioneer (early-succession) species (PS) were Cecropia

Viviane F. Favaretto; Carlos A. Martinez; Hilda H. Soriani; Rosa P. M. Furriel



Colloquium paper: how many tree species are there in the Amazon and how many of them will go extinct?  


New roads, agricultural projects, logging, and mining are claiming an ever greater area of once-pristine Amazonian forest. The Millennium Ecosystems Assessment (MA) forecasts the extinction of a large fraction of Amazonian tree species based on projected loss of forest cover over the next several decades. How accurate are these estimates of extinction rates? We use neutral theory to estimate the number, relative abundance, and range size of tree species in the Amazon metacommunity and estimate likely tree-species extinctions under published optimistic and nonoptimistic Amazon scenarios. We estimate that the Brazilian portion of the Amazon Basin has (or had) 11,210 tree species that reach sizes >10 cm DBH (stem diameter at breast height). Of these, 3,248 species have population sizes >1 million individuals, and, ignoring possible climate-change effects, almost all of these common species persist under both optimistic and nonoptimistic scenarios. At the rare end of the abundance spectrum, however, neutral theory predicts the existence of approximately 5,308 species with <10,000 individuals each that are expected to suffer nearly a 50% extinction rate under the nonoptimistic deforestation scenario and an approximately 37% loss rate even under the optimistic scenario. Most of these species have small range sizes and are highly vulnerable to local habitat loss. In ensembles of 100 stochastic simulations, we found mean total extinction rates of 20% and 33% of tree species in the Brazilian Amazon under the optimistic and nonoptimistic scenarios, respectively. PMID:18695228

Hubbell, Stephen P; He, Fangliang; Condit, Richard; Borda-de-Agua, Luís; Kellner, James; Ter Steege, Hans



Some autecological characteristics of early to late successional tree species in Venezuela  

NASA Astrophysics Data System (ADS)

The breadth of the continuum concept of strategy with respect to succession was tested on 21 tree and shrub species common in either unlogged or logged stands, respectively, in the Forest Reserve of Caparo, Venezuela, by examining morphological, physiological and population characteristics. Based on a preliminary abundance analysis, `early', `mid' and `late' successional species as well as `generalists' were distinguished. Early successional species, i.e. Ochroma lagopus, Heliocarpus popayanensis and Cecropia peltata were similar in many autecological aspects, e.g. monolayered leaf arrangement, orthotropic architectural models, no adaptive reiteration, clumped distribution, but differed in gap association and distribution along a drainage gradient. Mid-successional species established themselves both in large and small gaps (> 300 m[sup2 ]; 80-300 m[sup2 ]) and showed a clumped to regular distribution pattern in logged areas; they exhibited more diverse crown and leaf characteristics than early successional species. Late successional species established themselves only in small gaps and understorey, and showed a regular spatial pattern in undisturbed areas. All late successional species displayed architectural models with plagiotropic lateral axes and showed a multilayered leaf arrangement. Adaptive reiteration was a common feature of late successional species which could be further subdivided into large, medium-sized and small trees, indicating different light requirements at maturity. Generalists were common treelet and shrub species in both disturbed and undisturbed sites where they are also capable of completing their life cycle. The light compensation point (LCP) of an individual plant was strongly influenced by its crown illuminance. Large late successional species showed the widest range of LCP values, reflecting the increasing light availability with increasing height in mature forest. On the basis of many autecological characteristics, it was found (i) that there is in fact a continuum of species strategies with respect to succession even among early and mid-successional species and (ii) that the latter group of species showed the widest breadth of autecological traits, reflecting the heterogeneous environment in which they establish and mature.

Kammesheidt, Ludwig



Responses of four succession tree species in low subtropics to enhanced UV-B radiation in the field  

Microsoft Academic Search

The tested tree species included pioneer species Acacia mangium, early succession stage species Schima superba, mesophyte intermediate-succession species Machilus chinensis, and shade-tolerant plant or late-succession species Cryptocarya concinna which occur in the lower subtropical forest community. A comparison with the current ambient level of UV-B radiation (UV-B)\\u000a showed the leaf net photosynthetic rate (P\\u000a N), transpiration rate (E), and stomatal

X. A. Cai; S. L. Peng; H. P. Xia; P. Zhao; F. Mason



Separating the Effects of Environment and Space on Tree Species Distribution: From Population to Community  

PubMed Central

Quantifying the relative contributions of environmental conditions and spatial factors to species distribution can help improve our understanding of the processes that drive diversity patterns. In this study, based on tree inventory, topography and soil data from a 20-ha stem-mapped permanent forest plot in Guangdong Province, China, we evaluated the influence of different ecological processes at different spatial scales using canonical redundancy analysis (RDA) at the community level and multiple linear regression at the species level. At the community level, the proportion of explained variation in species distribution increased with grid-cell sizes, primarily due to a monotonic increase in the explanatory power of environmental variables. At the species level, neither environmental nor spatial factors were important determinants of overstory species' distributions at small cell sizes. However, purely spatial variables explained most of the variation in the distributions of understory species at fine and intermediate cell sizes. Midstory species showed patterns that were intermediate between those of overstory and understory species. At the 20-m cell size, the influence of spatial factors was stronger for more dispersal-limited species, suggesting that much of the spatial structuring in this community can be explained by dispersal limitation. Comparing environmental factors, soil variables had higher explanatory power than did topography for species distribution. However, both topographic and edaphic variables were highly spatial structured. Our results suggested that dispersal limitation has an important influence on fine-intermediate scale (from several to tens of meters) species distribution, while environmental variability facilitates species distribution at intermediate (from ten to tens of meters) and broad (from tens to hundreds of meters) scales.

Lin, Guojun; Stralberg, Diana; Gong, Guiquan; Huang, Zhongliang; Ye, Wanhui; Wu, Linfang



Modelling predicts positive and negative interactions between three Australian tropical tree species in monoculture and binary mixture  

Microsoft Academic Search

Computer modelling promises to be an important tool for analysing and predicting interactions between trees within mixed species forest plantations. This study explored the use of an individual-based mechanistic model as a predictive tool for designing mixed species plantations of Australian tropical trees. The ‘spatially explicit individually based-forest simulator’ (SeXI-FS) modelling system was used to describe the spatial interaction of

Daniel G. Manson; Jim Hanan; Mark Hunt; Mila Bristow; Peter D. Erskine; David Lamb; Susanne Schmidt



The influence of tree species on canopy soil nutrient status in a tropical lowland wet forest in Costa Rica  

Microsoft Academic Search

The canopy is host to a large percentage of the flora and fauna in tropical wet forests and is distinct from the forest floor\\u000a in plant richness, soil type and microclimate. In this study, we examined the influence of tree species and season on soil\\u000a nutrient cycling processes in canopy soils of four tree species common to Costa Rican wet

Catherine L. Cardelús; Michelle C. Mack; Carrie Woods; Jennie DeMarco; Kathleen K. Treseder



Retranslocation of foliar nutrients in evergreen tree species planted in a Mediterranean environment.  


Internal nutrient recycling through retranslocation (resorption) is important for meeting the nutrient demands of new tissue production in trees. We conducted a comparative study of nutrient retranslocation from leaves of five tree species from three genera grown in plantation forests for commercial or environmental purposes in southern Australia--Acacia mearnsii De Wild., Eucalyptus globulus Labill., E. fraxinoides H. Deane & Maiden, E. grandis W. Hill ex Maiden and Pinus radiata D. Don. Significant amounts of nitrogen, phosphorus and potassium were retranslocated during three phases of leaf life. In the first phase, retranslocation occurred from young leaves beginning 6 months after leaf initiation, even when leaves were physiologically most active. In the second phase, retranslocation occurred from mature green leaves during their second year, and in the third phase, retranslocation occurred during senescence before leaf fall. Nutrient retranslocation occurred mainly in response to new shoot production. The pattern of retranslocation was remarkably similar in the leaves of all study species (and in the phyllodes of Casuarina glauca Sieber ex Spreng.), despite their diverse genetics, leaf forms and growth rates. There was no net retranslocation of calcium in any of the species. The amounts of nutrients at the start of each pre-retranslocation phase had a strong positive relationship with the amounts subsequently retranslocated, and all species fitted a common relationship. The percentage reduction in concentration or content (retranslocation efficiency) at a particular growth phase is subject to many variables, even within a species, and is therefore not a meaningful measure of interspecific variation. It is proposed that the pattern of retranslocation and its governing factors are similar among species in the absence of interspecies competition for growth and crown structure which occurs in mixed species stands. PMID:18055429

Fife, D N; Nambiar, E K S; Saur, E



Physiological characteristics of tropical rain forest tree species: A basis for the development of silvicultural technology  

PubMed Central

The physiological characteristics of the dominant tree species in the tropical rain forest mainly belonging to dipterocarps as well as the environmental conditions especially for the light in the forest were studied to establish the silvicultural system for the forest regeneration in the tropical South Asia. The flowering patterns of the dipterocarp trees are usually irregular and unpredictable, which make difficult to collect sufficient seeds for raising the seedlings. The field survey revealed the diverged features of the so-called gregarious or simultaneous flowering of various species of this group. Appropriate conditions and methods for the storage of the seeds were established according to the detailed analyses of the morphological and physiological characteristics of the seeds such as the low temperature tolerance and the moisture contents. The intensity and spectra of the light in the forest primarily determine the growth and the morphological development of the seedlings under the canopy. Based on the measurements of the diffused light at the sites in the tropical forest in the varying sunlight, the parameters such as “the steady state of the diffuse light” and “the turning point” were defined, which were useful to evaluate the light conditions in the forest. To improve the survival of the transplanted seedlings, a planting method of “the bare-root seedlings”, the seedlings easy to be handled by removal of all leaves, soil and pots, was developed. Its marked efficiency was proved with various dipterocarps and other tropical trees by the field trial in the practical scale. Tolerance of the various species to the extreme environmental conditions such as fires, acid soils and drought were examined by the experiments and the field survey, which revealed marked adaptability of Shorea roxburghii as a potential species for regeneration of the tropical forests.

SASAKI, Satohiko



Experimental warming studies on tree species and forest ecosystems: a literature review.  


Temperature affects a cascade of ecological processes and functions of forests. With future higher global temperatures being inevitable it is critical to understand and predict how forest ecosystems and tree species will respond. This paper reviews experimental warming studies in boreal and temperate forests or tree species beyond the direct effects of higher temperature on plant ecophysiology by scaling up to forest level responses and considering the indirect effects of higher temperature. In direct response to higher temperature (1) leaves emerged earlier and senesced later, resulting in a longer growing season (2) the abundance of herbivorous insects increased and their performance was enhanced and (3) soil nitrogen mineralization and leaf litter decomposition were accelerated. Besides these generalizations across species, plant ecophysiological traits were highly species-specific. Moreover, we showed that the effect of temperature on photosynthesis is strongly dependent on the position of the leaf or plant within the forest (canopy or understory) and the time of the year. Indirect effects of higher temperature included among others higher carbon storage in trees due to increased soil nitrogen availability and changes in insect performance due to alterations in plant ecophysiological traits. Unfortunately only a few studies extrapolated results to forest ecosystem level and considered the indirect effects of higher temperature. Thus more intensive, long-term studies are needed to further confirm the emerging trends shown in this review. Experimental warming studies provide us with a useful tool to examine the cascade of ecological processes in forest ecosystems that will change with future higher temperature. PMID:23689840

Chung, Haegeun; Muraoka, Hiroyuki; Nakamura, Masahiro; Han, Saerom; Muller, Onno; Son, Yowhan



Comparative height crown allometry and mechanical design in 22 tree species of Kuala Belalong rainforest, Brunei, Borneo.  


In rainforests, trunk size, strength, crown position, and geometry of a tree affect light interception and the likelihood of mechanical failure. Allometric relationships of tree diameter, wood density, and crown architecture vs. height are described for a diverse range of rainforest trees in Brunei, northern Borneo. The understory species follow a geometric model in their diameter-height relationship (slope, ? = 1.08), while the stress-elasticity models prevail (? = 1.27-1.61) for the midcanopy and canopy/emergent species. These relationships changed with ontogeny, especially for the understory species. Within species, the tree stability safety factor (SSF) and relative crown width decreased exponentially with increasing tree height. These trends failed to emerge in across-species comparisons and were reversed at a common (low) height. Across species, the relative crown depth decreased with maximum potential height and was indistinguishable at a common (low) height. Crown architectural traits influence SSF more than structural property of wood density. These findings emphasize the importance of applying a common reference size in comparative studies and suggest that forest trees (especially the understory group) may adapt to low light by having deeper rather than wider crowns due to an efficient distribution and geometry of their foliage. PMID:21636390

Osunkoya, Olusegun O; Omar-Ali, Kharunnisa; Amit, Norratna; Dayan, Juita; Daud, Dayanawati S; Sheng, Tan K



Clade Age and Species Richness Are Decoupled Across the Eukaryotic Tree of Life  

PubMed Central

Explaining the dramatic variation in species richness across the tree of life remains a key challenge in evolutionary biology. At the largest phylogenetic scales, the extreme heterogeneity in species richness observed among different groups of organisms is almost certainly a function of many complex and interdependent factors. However, the most fundamental expectation in macroevolutionary studies is simply that species richness in extant clades should be correlated with clade age: all things being equal, older clades will have had more time for diversity to accumulate than younger clades. Here, we test the relationship between stem clade age and species richness across 1,397 major clades of multicellular eukaryotes that collectively account for more than 1.2 million described species. We find no evidence that clade age predicts species richness at this scale. We demonstrate that this decoupling of age and richness is unlikely to result from variation in net diversification rates among clades. At the largest phylogenetic scales, contemporary patterns of species richness are inconsistent with unbounded diversity increase through time. These results imply that a fundamentally different interpretative paradigm may be needed in the study of phylogenetic diversity patterns in many groups of organisms.



Species delineation in the tree pathogen genus Celoporthe (Cryphonectriaceae) in southern Africa.  


The genus Celoporthe was first described when C. dispersa was discovered in South Africa associated with dieback and cankers on trees in the Myrtales. Four additional species were recently described from Eucalyptus and Syzygium cumini in China as well as S. aromaticum and Eucalyptus in Indonesia. Inoculation trials have shown that all Celoporthe species, including those that have not been found on Eucalyptus species in nature, are pathogenic to Eucalyptus and they are thus potentially threatening to commercial Eucalyptus forestry. New isolates, morphologically similar to Celoporthe, have been collected from S. legatti in South Africa and S. guineense in Zambia. Multigene phylogenetic analyses based on DNA sequences of the ITS region, TEF1? gene and two areas of the ?-tubulin gene revealed additional cryptic species in Celoporthe. Phylogenetic data were supported by morphological differences. These resulted in the description of two previously unknown species of Celoporthe, namely C. fontana and C. woodiana, for two of these cryptic groups, while the third group represented C. dispersa. These species all can readily infect Eucalyptus as well as several species of Syzygium, the latter of which are native to Africa. PMID:23233512

Vermeulen, Marcele; Gryzenhout, Marieka; Wingfield, Michael J; Roux, Jolanda



Effects of tree species richness and composition on moose winter browsing damage and foraging selectivity: an experimental study.  


The optimal foraging theory, the nutrient balance hypothesis, and the plant association theories predict that foraging decisions and resulting tree damage by large mammalian browsers may be influenced by the species richness and species composition of forest stands. This may lead to either associational susceptibility (increased damage on a focal plant in a mixed stand) or associational resistance (reduced damage in a mixed stand). Better understanding of the mechanisms and the relative importance of tree species richness and composition effects on foraging by mammalian browsers is needed to support sustainable management of forests and mammal populations. However, existing knowledge of forest diversity effects on foraging by large mammalian browsers comes largely from observational studies while experimental evidence is limited. We analysed winter browsing by moose (Alces alces L.) in a long-term, large-scale experiment in Finland, which represents a tree species richness gradient from monocultures to 2-, 3- and 5-species mixtures composed of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L.), Siberian larch (Larix sibirica Ledeb.), silver birch (Betula pendula Roth.) and black alder (Alnus glutinosa L.). The intensity of browsing per plot increased with tree species richness while browsing selectivity decreased with tree species being targeted more equally in species-rich mixtures. Tree species composition of a plot was also an important determinant of intensity of browsing. The greatest browsing occurred in plots containing preferred species (pine and birch) while intermediate preference species (larch and alder) experienced associational susceptibility when growing with pine and birch compared with their monocultures or mixtures without pine and birch. In contrast, we found no evidence of associational resistance; the presence of a least preferred species (spruce) in a mixture had no significant effect on moose browsing on other tree species. We demonstrate that the presence of alternative forage species allows moose to spend longer opportunistically foraging in a plot, resulting in increased level of damage in species-rich stands and stands containing preferred tree species. Our results highlight the limitations of the optimal foraging theory in predicting browsing patterns and demonstrate the importance of associational effects within mixed stands. PMID:23363076

Milligan, Harriet T; Koricheva, Julia



Nitrogen-fixing legume tree species for the reclamation of severely degraded lands in Brazil.  


The main challenges faced in the reclamation of severely degraded lands are in the management of the systems and finding plant species that will grow under the harsh conditions common in degraded soils. This is especially important in extremely adverse situations found in some substrates from mining activities or soils that have lost their upper horizons. Under these conditions, recolonization of the area by native vegetation through natural succession processes may be extremely limited. Once the main physical and chemical factors restrictive to plant growth are corrected or attenuated, the introduction of leguminous trees able to form symbioses with nodulating N?-fixing bacteria and arbuscular mycorrhizal fungi constitutes an efficient strategy to accelerate soil reclamation and initiate natural succession. These symbioses give the legume species a superior capacity to grow quickly in poor substrates and to withstand the harsh conditions presented in degraded soils. In this article we describe several successful results in Brazil using N?-fixing legume tree species for reclamation of areas degraded by soil erosion, construction and mining activities, emphasizing the potential of the technique to recover soil organic matter levels and restore ecosystem biodiversity and other environmental functions. PMID:21378065

Chaer, Guilherme Montandon; Resende, Alexander Silva; Campello, Eduardo Francia Carneiro; de Faria, Sergio Miana; Boddey, Robert Michael



Emission of short-chained oxygenated voc from the leaves of mature central european tree species  

NASA Astrophysics Data System (ADS)

The photolytic and oxidative destruction of volatile organic compounds (VOC) in the atmosphere results in a net production of tropospheric ozone. Oxygenated VOC (OVOC) are either directly emitted into the atmosphere or are produced there by oxidation of other hydrocarbons. Besides anthropogenic sources, the emission of OVOC by vegetation, particularly by forest ecosystems, is considered a major source of atmospheric OVOC. Exact numbers on emission rates from important tree species as well as production mechanisms that lead to the release of OVOC from leaves are, however, not known. In the present study, field campaigns were conducted in typical forest ecosystems in Germany in order to elucidate the spectrum and the amount of OVOC emitted by Central European tree species. Exchange data obtained were compared with physiological and meteorological parameters to obtain information on the factors controlling trace gas exchange. The field campaigns were accompanied by studies under controlled conditions in the laboratory. The poster presents data on carbonyl exchange between Picea abies, Fagus sylvatica, Carpinus betulus and other species and the atmosphere and indicates plant internal and meteorological factors (temperature, ambient OVOC concentrations, light intensities, water supply, etc.) that may determine exchange rates.

Kreuzwieser, J.; Cojocariu, C.; Rennenberg, H.



Multi-purpose seismic transducer  

SciTech Connect

A multi-purpose seismic transducer includes a first seismic sensor having a first transfer function. A transfer-function shaping filter is coupled to the output of the first seismic sensor. The filter is adjustable to shape the first transfer function to match a plurality of different second transfer functions.

Hall, E.M.



Multipurpose system for ecological monitoring  

Microsoft Academic Search

Moscow Research Television Institute has conducted theoretical and experimental researches concerning the integration of image sensors operating in different ranges on board of vehicles. On the base of these researches a prototype of multipurpose system for ecological monitoring is made. The scope of the system: ecological monitoring of each and water surface, control of sources of pollution and zones of

V. M. Berezansky



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

Microsoft Academic Search

Anthropogenic disturbance of ecosystem processes is increasingly being explored in urban settings. One profound impact is the striking increase in the distribution of invasive plant species. For example, Tree of Heaven (Ailanthus altissima, TOH), introduced into the U.S. from Asia in 1784, is a successful colonist of recently deforested habitats. As a result, remnant patches in urban ecosystems have become

C. Swan; B. Healey



Consumer preference for seeds and seedlings of rare species impacts tree diversity at multiple scales.  


Positive density-dependent seed and seedling predation, where herbivores selectively eat seeds or seedlings of common species, is thought to play a major role in creating and maintaining plant community diversity. However, many herbivores and seed predators are known to exhibit preferences for rare foods, which could lead to negative density-dependent predation. In this study, we first demonstrate the occurrence of increased predation of locally rare tree species by a widespread group of insular seed and seedling predators, land crabs. We then build computer simulations based on these empirical data to examine the effects of such predation on diversity patterns. Simulations show that herbivore preferences for locally rare species are likely to drive scale-dependent effects on plant community diversity: at small scales these foraging patterns decrease plant community diversity via the selective consumption of rare plant species, while at the landscape level they should increase diversity, at least for short periods, by promoting clustered local dominance of a variety of species. Finally, we compared observed patterns of plant diversity at the site to those obtained via computer simulations, and found that diversity patterns generated under simulations were highly consistent with observed diversity patterns. We posit that preference for rare species by herbivores may be prevalent in low- or moderate-diversity systems, and that these effects may help explain diversity patterns across different spatial scales in such ecosystems. PMID:23229391

Young, Hillary S; McCauley, Douglas J; Guevara, Roger; Dirzo, Rodolfo



Impact of tree species on nutrient stocks in the forest floors of a temperate forest ecosystem.  


To investigate the effect of silvicultural methods on forest floor C, N and elements stocks an experiment was carried out by sampling the forest floors of a 100-120-years-old species including beech, Norway spruce and mixed beech-spruce at the Solling forest, Germany. While the stocks of carbon and nitrogen in the forest floors of pure beech and spruce were significantly influenced by species specific differences of litter quality (p < 0.001), no significant differences were detected between pure and mixed species stands. Forest floor mass, some elements concentrations and C/nutrient ratios were significantly affected by tree species differences, while no clear dependency between pH and site specific effects was found among pure stands. Acid element concentrations in the forest floors of pure spruce were remarkably higher than the values obtained at beech stand, while the stocks were to some extent modified in mixed silviculture. The base-pump effect of beech significantly controlled variation between mono cultures on calcium stocks, while the acidifying effect of spruce in mixtures resulted in modification of Ca stocks of forest floors. The status of other nutrient elements at mixed species cultures due to variation in nutritional properties and composition of litter compared to pure species were between the range of values observed in mono cultures. PMID:18819535

Bagherzadeh, Ali; Brumme, Rainer; Beese, Friedrich



Effect of dust load on the leaf attributes of the tree species growing along the roadside.  


Dust is considered as one of the most widespread air pollutants. The objective of the study was to analyse the effect of dust load (DL) on the leaf attributes of the four tree species planted along the roadside at a low pollution Banaras Hindu University (BHU) campus and a highly polluted industrial area (Chunar, Mirzapur) of India. The studied leaf attributes were: leaf area, specific leaf area (SLA), relative water content (RWC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), chlorophyll content (Chl), maximum stomatal conductance (Gs(max)), maximum photosynthetic rate (A (max)) and intrinsic water-use efficiency (WUEi). Results showed significant effect of sites and species for DL and the leaf attributes. Average DL across the four tree species was greater at Chunar, whereas, the average values of leaf attributes were greater at the BHU campus. Maximum DL was observed for Tectona grandis at Chunar site and minimum for Syzygium cumini at BHU campus. Across the two sites, maximum value of SLA, Chl and Gs(max) were exhibited by S. cumini, whereas, the greatest value of RWC, LNC, LPC, A (max) and WUEi were observed in Anthocephalus cadamba. A. cadamba and S. cumini exhibited 28 and 27 times more dust accumulation, respectively, at the most polluted Chunar site as compared to the BHU campus. They also exhibited less reduction in A (max) due to dust deposition as compared to the other two species. Therefore, both these species may be promoted for plantation along the roadside of the sites having greater dust deposition. PMID:22367367

Chaturvedi, R K; Prasad, Shikha; Rana, Savita; Obaidullah, S M; Pandey, Vijay; Singh, Hema



Stem and leaf hydraulics of congeneric tree species from adjacent tropical savanna and forest ecosystems.  


Leaf and stem functional traits related to plant water relations were studied for six congeneric species pairs, each composed of one tree species typical of savanna habitats and another typical of adjacent forest habitats, to determine whether there were intrinsic differences in plant hydraulics between these two functional types. Only individuals growing in savanna habitats were studied. Most stem traits, including wood density, the xylem water potential at 50% loss of hydraulic conductivity, sapwood area specific conductivity, and leaf area specific conductivity did not differ significantly between savanna and forest species. However, maximum leaf hydraulic conductance (K (leaf)) and leaf capacitance tended to be higher in savanna species. Predawn leaf water potential and leaf mass per area were also higher in savanna species in all congeneric pairs. Hydraulic vulnerability curves of stems and leaves indicated that leaves were more vulnerable to drought-induced cavitation than terminal branches regardless of genus. The midday K (leaf) values estimated from leaf vulnerability curves were very low implying that daily embolism repair may occur in leaves. An electric circuit analog model predicted that, compared to forest species, savanna species took longer for their leaf water potentials to drop from predawn values to values corresponding to 50% loss of K (leaf) or to the turgor loss points, suggesting that savanna species were more buffered from changes in leaf water potential. The results of this study suggest that the relative success of savanna over forest species in savanna is related in part to their ability to cope with drought, which is determined more by leaf than by stem hydraulic traits. Variation among genera accounted for a large proportion of the total variance in most traits, which indicates that, despite different selective pressures in savanna and forest habitats, phylogeny has a stronger effect than habitat in determining most hydraulic traits. PMID:18049826

Hao, Guang-You; Hoffmann, William A; Scholz, Fabian G; Bucci, Sandra J; Meinzer, Frederick C; Franco, Augusto C; Cao, Kun-Fang; Goldstein, Guillermo



Historical Human Footprint on Modern Tree Species Composition in the Purus-Madeira Interfluve, Central Amazonia  

PubMed Central

Background Native Amazonian populations managed forest resources in numerous ways, often creating oligarchic forests dominated by useful trees. The scale and spatial distribution of forest modification beyond pre-Columbian settlements is still unknown, although recent studies propose that human impact away from rivers was minimal. We tested the hypothesis that past human management of the useful tree community decreases with distance from rivers. Methodology/Principal Findings In six sites, we inventoried trees and palms with DBH?10 cm and collected soil for charcoal analysis; we also mapped archaeological evidence around the sites. To quantify forest manipulation, we measured the relative abundance, richness and basal area of useful trees and palms. We found a strong negative exponential relationship between forest manipulation and distance to large rivers. Plots located from 10 to 20 km from a main river had 20–40% useful arboreal species, plots between 20 and 40 km had 12–23%, plots more than 40 km had less than 15%. Soil charcoal abundance was high in the two sites closest to secondary rivers, suggesting past agricultural practices. The shortest distance between archaeological evidence and plots was found in sites near rivers. Conclusions/Significance These results strongly suggest that past forest manipulation was not limited to the pre-Columbian settlements along major rivers, but extended over interfluvial areas considered to be primary forest today. The sustainable use of Amazonian forests will be most effective if it considers the degree of past landscape domestication, as human-modified landscapes concentrate useful plants for human sustainable use and management today.

Levis, Carolina; de Souza, Priscila Figueira; Schietti, Juliana; Emilio, Thaise; Pinto, Jose Luiz Purri da Veiga; Clement, Charles R.; Costa, Flavia R. C.



Interspecific variation in the response of growth, crown morphology, and survivorship to light of six tree species in the conifer belt of the Bhutan Himalayas  

Microsoft Academic Search

Abstract: The responses of radial and height growth, plant architecture, and the probability of mortality of saplings to varying light levels were quantified for six tree species in temperate,conifer forests of the Bhutan Himalayas. Increases in growth,with increasing light were comparable,with those of high latitude tree species but lower than those of tropi - cal tree species and temperate,species in

Georg Gratzer; Andras Darabant; Purna B. Chhetri; Prem Bahadur Rai; Otto Eckmüllner



Effect of leaf phenology on canopy exchange processes in temperate tree species  

NASA Astrophysics Data System (ADS)

Many forest ecosystems worldwide are exposed to enhanced atmospheric deposition of nitrogen (N) and sulphur (S), which may have adverse effects on forest structure and functioning. Canopy exchange processes, i.e. ion exchange between the water layer covering plant tissues and the underlying apoplast, as well as stomatal or cuticular uptake of gases, can play an important role in determining the impact of air pollution on forest ecosystems and in studying internal nutrient cycling. However, leaf phenology exhibits a large influence on these processes, in particular for deciduous trees where leaf longevity is restricted to one growing season. In a first experiment, 15N-labelled sources were used to investigate the uptake of dissolved (NH4+, NO3-) and gaseous N (NH3) by leaves and twigs at four phenological stages, i.e. the period of leaf development, the fully leafed period, the period of leaf senescence and the leafless period. For this purpose, potted saplings of tree deciduous species, i.e. European beech (Fagus sylvatica L.), pedunculate oak (Quercus robur L.) and common birch (Betula pendula L.), and one coniferous species, Scots pine (Pinus sylvestris L.) were used. Along with the uptake of dissolved N, leaf water storage capacity, leaf wettability and canopy leaching of ions in throughfall water were assessed. In general, dissolved N uptake was highest during leaf senescence, while for gaseous N this was during the fully leafed period. Dissolved NH4+ uptake was significantly correlated with the leaching of base cations (K+, Mg2+ and Ca2+), but only during the growing season. Furthermore, dissolved N uptake was related to leaf wettability and not to leaf water storage capacity. A second experiment assessed the temporal variation of throughfall water along a vertical gradient within the canopy of an adult European beech tree. To analyse temporal trends a generalized additive model was used, which showed that throughfall deposition at all canopy levels followed the same pattern over time. Furthermore, canopy exchange processes were significantly higher during the growing season than during the dormant season, with higher between-season variation for base cations than for N compounds. This research showed that leaf phenology has a significant impact on canopy exchange processes in temperate tree species and that it is recommended to consider each phenological period separately when assessing the response of a forest ecosystem to air pollution.

Adriaenssens, S.; Staelens, J.; Wuyts, K.; Samson, R.; Boeckx, P. F.; Verheyen, K.



Interannual consistency in canopy stomatal conductance control of leaf water potential across seven tree species.  


We investigated interannual variability of canopy transpiration per unit ground area (E (C)) and per unit leaf area (E (L)) across seven tree species in northern Wisconsin over two years. These species have previously been shown to be sufficient to upscale stand-level transpiration to the landscape level during one growing season. Our objective was to test whether a simple plant hydraulic model could capture interannual variation in transpiration. Three species, wetland balsam fir (Abies balsamea (L.) Mill), basswood (Tilia Americana L.) and speckled alder (Alnus rugosa (DuRoi) Spreng), had no change in E (C) or E (L) between 2000 and 2001. Red pine (Pinus resinosa Ait) had a 57 and 19% increase in E (C) and E (L), respectively, and sugar maple (Acer saccharum Marsh) had an 83 and 41% increase in E (C) and E (L), respectively, from 2000 to 2001. Quaking aspen (Populus tremuloides Michx) had a 50 and 21% decrease in E (C) and E (L), respectively, from 2000 to 2001 in response to complete defoliation by forest tent caterpillar (Malascoma distria Hüber) and subsequent lower total leaf area index of the reflushed foliage. White cedar (Thuja occidentalis L.) had a 20% decrease in both E (C) and E (L) caused by lowered surface water in wetlands in 2001 because of lower precipitation and wetland flow management. Upland A. balsamea increased E (L) and E (C) by 55 and 53%, respectively, as a result of release from light competition of the defoliated, overstory P. tremuloides. We hypothesized that regardless of different drivers of interannual variability in E (C) and E (L), minimum leaf water potential would be regulated at the same value. Minimum midday water potentials were consistent over the two years within each of the seven species despite large changes in transpiration between years. This regulation was independently verified by the exponential saturation between daily E (C) and vapor pressure deficit (D) and the tradeoff between a reference canopy stomatal conductance (G (S)) and the sensitivity of G (S) to D, indicating that trees with high G (S) must decrease G (S) in response to atmospheric drought faster than trees with low G (S). Our results show that models of forest canopy transpiration can be simplified by incorporating G (S) regulation of minimum leaf water potential for isohydric species. PMID:17169902

Ewers, B E; Mackay, D S; Samanta, S



Mapping regional distribution of a single tree species: Whitebark pine in the Greater Yellowstone Ecosystem  

USGS Publications Warehouse

Moderate resolution satellite imagery traditionally has been thought to be inadequate for mapping vegetation at the species level. This has made comprehensive mapping of regional distributions of sensitive species, such as whitebark pine, either impractical or extremely time consuming. We sought to determine whether using a combination of moderate resolution satellite imagery (Landsat Enhanced Thematic Mapper Plus), extensive stand data collected by land management agencies for other purposes, and modern statistical classification techniques (boosted classification trees) could result in successful mapping of whitebark pine. Overall classification accuracies exceeded 90%, with similar individual class accuracies. Accuracies on a localized basis varied based on elevation. Accuracies also varied among administrative units, although we were not able to determine whether these differences related to inherent spatial variations or differences in the quality of available reference data.

Landenburger, L.; Lawrence, R. L.; Podruzny, S.; Schwartz, C. C.



Liberomyces gen. nov. with two new species of endophytic coelomycetes from broadleaf trees.  


During a study of endophytic and saprotrophic fungi in the sapwood and phloem of broadleaf trees (Salix alba, Quercus robur, Ulmus laevis, Alnus glutinosa, Betula pendula) fungi belonging to an anamorphic coelomycetous genus not attributable to a described taxon were detected and isolated in pure culture. The new genus, Liberomyces, with two species, L. saliciphilus and L. macrosporus, is described. Both species have subglobose conidiomata containing holoblastic sympodial conidiogenous cells. The conidiomata dehisce irregularly or by ostiole and secrete a slimy suspension of conidia. The conidia are hyaline, narrowly allantoid with a typically curved distal end. In L. macrosporus simultaneous production of synanamorph with thin filamentous conidia was observed occasionally. The genus has no known teleomorph. Related sequences in the public databases belong to endophytes of angiosperms. Phylogenetic analysis revealed a position close to the Xylariales (Sordariomycetes), but family and order affiliation remained unclear. PMID:21937729

Pazoutová, Sylvie; Srutka, Petr; Holusa, Jaroslav; Chudícková, Milada; Kubátová, Alena; Kolarík, Miroslav



Contrasting responses to ectomycorrhizal inoculation in seedlings of six tropical African tree species.  


Five caesalpinioid legumes, Afzelia africana, Afzelia bella, Anthonotha macrophylla, Cryptosepalum tetraphylum and Paramacrolobium coeruleum, and one Euphorbiaceae species, Uapaca somon, with a considerable range in seed sizes, exhibited different responses to inoculation by four species of ectomycorrhizal (ECM) fungi, Scleroderma dictyosporum, S. verrucosum, Pisolithus sp. and one thelephoroid sp. in greenhouse conditions. Thelephoroid sp. efficiently colonized seedlings of all of the five caesalpinioid legumes except U. somon, but provided no more growth benefit than the other fungi. Thelephoroid sp. and S. dictyosporum colonized seedlings of U. somon poorly, but stimulated plant growth more than the other fungi. The relative mycorrhizal dependency (RMD) values of the caesalpinioid legumes were never higher than 50%, whilst U. somon had RMD values ranging from 84.6 to 88.6%, irrespective of the fungal species. The RMD values were negatively related to seed mass for all plant species. Potassium concentrations in leaves were more closely related than phosphorus to the stimulation of seedling biomass production by the ECM fungi. Our data support the hypothesis that African caesalpinioid legumes and euphorbe tree species with smaller seeds show higher RMD values than those with the larger seeds. PMID:16007470

Diédhiou, A G; Guèye, O; Diabaté, M; Prin, Y; Duponnois, R; Dreyfus, B; Bâ, A M



Restinga forests of the Brazilian coast: richness and abundance of tree species on different soils.  


The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in species richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some species are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant species in Restinga forests than basic soil fertility attributes. PMID:22886165

Magnago, Luiz F S; Martins, Sebastião V; Schaefer, Carlos E G R; Neri, Andreza V



Above- and belowground interactions drive habitat segregation between two cryptic species of tropical trees.  


In the lowlands of central Panama, the Neotropical pioneer tree Trema micrantha (sensu lato) exists as two cryptic species: "landslide" Trema is restricted to landslides and road embankments, while "gap" Trema occurs mostly in treefall gaps. In this study, we explored the relative contributions of biotic interactions and physical factors to habitat segregation in T. micrantha. Field surveys showed that soils from landslides were significantly richer in available phosphorus and harbored distinct arbuscular mycorrhizal fungal (AMF) communities compared to gap soils. Greenhouse experiments designed to determine the effect of these abiotic and biotic differences showed that: (1) both landslide and gap species performed better in sterilized soil from their own habitat, (2) the availability of phosphorus and nitrogen was limiting in gap and landslide soils, respectively, (3) a standardized AMF inoculum increased performance of both species, but primarily on gap soils, and (4) landslide and gap species performed better when sterilized soils were inoculated with the microbial inoculum from their own habitat. A field experiment confirmed that survival and growth of each species was highest in its corresponding habitat. This experiment also showed that browsing damage significantly decreased survival of gap Trema on landslides. We conclude that belowground interactions with soil microbes and aboveground interactions with herbivores contribute in fundamental ways to processes that may promote and reinforce adaptive speciation. PMID:21560675

Pizano, Camila; Mangan, Scott A; Herre, Edward Allen; Eom, Ahn-Heum; Dalling, James W



Direct measurements of intervessel pit membrane hydraulic resistance in two angiosperm tree species.  


The hydraulic resistance of pit membranes was measured directly in earlywood vessels of Fraxinus americana and Ulmus americana. The area-specific resistance of pit membranes (r(mem)) was higher than modeled or measured values obtained previously for hardwood species, with r(mem) of 5.24 × 10(3) MPa·s·m(-1) for Fraxinus and 2.56 × 10(3) MPa·s·m(-1) for Ulmus. The calculated resistance of pit canals was three orders of magnitude below total pit resistance indicating that pit membranes contributed the majority of resistance. Scanning electron microscopy indicated that pit membranes of Ulmus were thinner and more porous than those of Fraxinus, consistent with the difference in r(mem) between the species. Measurements of average vessel diameter and length and area of wall overlap with neighboring vessels were used to partition the vascular resistance between vessel lumen and pit membrane components. Pit membrane resistance accounted for 80% of the total resistance in Fraxinus and 87% in Ulmus in 2-yr-old branch sections. However, measurements of vessel dimensions in the trunk suggest that the division of resistance between pit membrane and lumen components would be closer to co-limiting in older regions of the tree. Thus, pit membrane resistance may be of greater relative importance in small branches than in older regions of mature trees. PMID:21642164

Choat, Brendan; Brodie, Tyler W; Cobb, Alexander R; Zwieniecki, Maciej A; Holbrook, N Michele



[Light response curve of dominant tree species photosynthesis in broadleaved Korean pine forest of Changbai mountain].  


Based on the measurements of leaf photosynthesis, the light response curves of Pinus koraiensis, Tilia amurensis, Quercus mongolica and Fraxinus mandshurica photosynthesis in broadleaved Korean pine forest of Changbai Mountains were fitted with rectangle and non-rectangle hyperbolae. The results showed that rectangle hyperbola was simpler for fitting, while non-rectangle hyperbola was more reasomable because of its fitted results better matched physiological meanings. The values of intrinsic quantum efficiency for CO2 uptake (alpha), light-saturated net photosynthetic rate (Pmax), and dark respiration rate (Rd) of the four tree species were higher when fitted with rectangle hyperbola than with non-rectangle hyperbola, while that of light compensation point (Lcp) varied with tree species. The values of alpha and Rd obtained from the two hyperholae had the same sequences, i.e., F. mandshurica > T. amurensis > Q. mongolica > P. koraiensis for alpha, and F. mandshurica > Q. mongolica > T. amurensis > P. koraiensis for Rd, but for Pmax and Lcp, the sequences were not the same. PMID:17147159

Zhang, Mi; Wu, Jiabing; Guan, Dexin; Shi, Tingting; Chen, Pengshi; Ji, Ruipeng



Early seedling establishment of two tropical montane cloud forest tree species: The role of native and exotic grasses  

Microsoft Academic Search

Tropical montane cloud forest has been undergoing a drastic reduction because of its widespread conversion to pastures. Once these forests have been cleared exotic grasses are deliberately introduced for forage production. Exotic grass species commonly form monodominant stands and produce more biomass than native grass species, resulting in the inhibition of secondary succession and tree regeneration. The purpose of this

Aline Ortega-Pieck; Fabiola López-Barrera; Neptalí Ramírez-Marcial; José G. García-Franco



Bioinformatic analysis of ESTs collected by Sanger and pyrosequencing methods for a keystone forest tree species: oak  

Microsoft Academic Search

BACKGROUND: The Fagaceae family comprises about 1,000 woody species worldwide. About half belong to the Quercus family. These oaks are often a source of raw material for biomass wood and fiber. Pedunculate and sessile oaks, are among the most important deciduous forest tree species in Europe. Despite their ecological and economical importance, very few genomic resources have yet been generated

Saneyoshi Ueno; Grégoire Le Provost; Valérie Léger; Christophe Klopp; Céline Noirot; Jean-Marc Frigerio; Franck Salin; Jérôme Salse; Michael Abrouk; Florent Murat; Oliver Brendel; Jérémy Derory; Pierre Abadie; Patrick Léger; Cyril Cabane; Aurélien Barré; Antoine de Daruvar; Arnaud Couloux; Patrick Wincker; Marie-Pierre Reviron; Antoine Kremer; Christophe Plomion



Plasticity in leaf traits of 38 tropical tree species in response to light; relationships with light demand and adult stature  

Microsoft Academic Search

1. The sun¿shade acclimation and plasticity of 16 functional leaf traits of 38 tropical tree species were studied in relation to their light demand, maximum adult stature and ontogenetic changes in crown exposure. 2. Species differed significantly in all leaf traits, which explained a large part of the observed variation (average R2 = 0·72). Light had a significant effect on

D. M. A. Rozendaal; V. H. Hurtado; L. Poorter



Light-dependent changes in biomass allocation and their importance for growth of rain forest tree species  

Microsoft Academic Search

1. Sapling growth of six rain forest tree species was compared to evaluate whether species respond in a similar way to a natural light gradient. Saplings were measured non-destructively; production and loss of leaves, stem and branches were analysed in detail. 2. Sapling height growth was positively related to light environment and leaf area. No single descriptor of light environment

L. Poorter



Developing risk hypotheses and selecting species for assessing non-target impacts of GM trees with novel traits: the case of altered-lignin pine trees.  


A procedure is presented for developing environmental risk hypotheses associated with the deployment of forest trees genetically modified to have altered wood properties and for selecting non-target species to test these hypotheses. Altered-lignin Pinus radiata trees intended for use in New Zealand are used as a hypothetical case study to illustrate our approach. Firstly, environmental management goals (such as wood production, flood control or preservation of biodiversity) were identified and linked to the forest attributes they require. Necessary conditions for each attribute were listed and appropriate assessment endpoints for them developed. For example, biological control of pests may be one condition necessary for a forest to have healthy trees, and the diversity and abundance of natural enemy species in the forest could be an appropriate assessment endpoint for measuring this condition. A conceptual model describing the relationships between an altered-lignin GM pine tree and potentially affected invertebrates and micro-organisms in a plantation forest was used to develop a set of risk hypotheses describing how the GM trees might affect each assessment endpoint. Because purified lignin does not represent the properties it imparts to wood, maximum hazard dose tests with non-target organisms, as are used to inform toxin risk assessment, cannot be conducted. Alternative experiments, based on current knowledge of the responses of organisms to lignin, must be designed. A screening method was adapted and applied to a database of invertebrate species known to inhabit New Zealand pine forests to identify and prioritize non-target invertebrate species that could be used as experimental subjects for examining these hypotheses. The screening model and its application are presented, along with a set of recommendations for pre-release tests with GM pines and potentially affected invertebrates and micro-organisms. PMID:22293130

Malone, Louise A; Todd, Jacqui H; Burgess, Elisabeth P J; Walter, Christian; Wagner, Armin; Barratt, Barbara I P



Structure and regeneration dynamics of dominant tree species along altitudinal gradient in a dry valley slopes of the Bhutan Himalaya  

Microsoft Academic Search

The aim of our study was to characterize the structure and regeneration dynamics of dominant tree species along altitudinal gradient in dry valley slopes of the Bhutan Himalaya. In the typical dry valley slopes of west-central Bhutan, we analyzed forest stratification, tree crown projection, and population structure from lower dry valley bottom (1520m a.s.l.) to upper humid ridge top (3370m

Pema Wangda; Masahiko Ohsawa



Phytoseiid mites (Acari: Phytoseiidae) on apple trees and in surrounding vegetation in southern Finland. Densities and species composition  

Microsoft Academic Search

Leaf samples were collected from sprayed (n=29) and unsprayed (n=19) apple orchards, from the surrounding vegetation (n=58) and from one arboretum (n=12), altogether from 46 plant species (1–5 samples each). The density of phytoseiid mites averaged 1.2 mites\\/leaf on unsprayed apple trees, but only 0.06 mites\\/leaf on sprayed trees. The phytoseiid density exceeded 1\\/leaf onAesculus hippocastani, Aristolochia macrophylla, Corylus avellana,

T. Tuovinen; J. A. H. Rokx



Predicting the Potential Future Distribution of Four Tree Species in Ohio Using Current Habitat Availability and Climatic Forcing  

Microsoft Academic Search

Weinvestigated the effect of habitat loss on the ability of trees to shift in distribution across a landscape dominated by\\u000a agriculture. The potential distribution shifts of four tree species (Diospyros virginiana, Oxydendron arboreum, Pinus virginiana, Quercus falcata var. falcata) whose northern distribution limits fall in the southern third of Ohio were used to assess possible distribution shift scenarios\\u000a as a

Mark W. Schwartz; Louis R. Iverson; Anantha M. Prasad



Tagetes: A multipurpose plant  

Microsoft Academic Search

Tagetes species, popularly known as marigold, are grown as ornamental plants and thrive in varied agroclimates. Bioactive extracts of different Tagetes parts exhibit nematocidal, fungicidal and insecticidal activity. Nematocidal activity of roots is attributed to thienyls while the biocidal components of the essential oil from flowers and leaves are terpenoids. Also carotenoid pigments from Tagetes are useful in food coloring.

Padma Vasudevan; Suman Kashyap; Satyawati Sharma



Surface tension phenomena in the xylem sap of three diffuse porous temperate tree species.  


In plant physiology models involving bubble nucleation, expansion or elimination, it is typically assumed that the surface tension of xylem sap is equal to that of pure water, though this has never been tested. In this study we collected xylem sap from branches of the tree species Populus tremuloides, Betula papyrifera and Sorbus aucuparia over 3 months. We measured the instantaneous surface tension and followed changes over a period of 0.5-5 h using the pendant drop technique. In all three species the instantaneous surface tension was equal to or within a few percent of that of pure water. Further, in B. papyrifera and S. aucuparia the change over time following drop establishment, although significant, was very small. In P. tremuloides, however, there was a steep decline in surface tension over time that leveled off towards values 21-27% lower than that of pure water. This indicated the presence of surfactants. The values were lower for thinner distal branch segments than for proximal ones closer to the trunk. In some species it appears valid to assume that the surface tension of xylem sap is equal to that of water. However, in branch segments of P. tremuloides close to the terminal bud and hence potentially in other species as well, it may be necessary to take into account the presence of surfactants that reduce the surface tension over time. PMID:21470981

Christensen-Dalsgaard, Karen K; Tyree, Melvin T; Mussone, Paolo G



Global meta-analysis of wood decomposition rates: a role for trait variation among tree species?  


The carbon flux from woody debris, a crucial uncertainty within global carbon-climate models, is simultaneously affected by climate, site environment and species-based variation in wood quality. In the first global analysis attempting to explicitly tease out the wood quality contribution to decomposition, we found support for our hypothesis that, under a common climate, interspecific differences in wood traits affect woody debris decomposition patterns. A meta-analysis of 36 studies from all forested continents revealed that nitrogen, phosphorus, and C : N ratio correlate with decomposition rates of angiosperms. In addition, gymnosperm wood consistently decomposes slower than angiosperm wood within common sites, a pattern that correlates with clear divergence in wood traits between the two groups. New empirical studies are needed to test whether this difference is due to a direct effect of wood trait variation on decomposer activity or an indirect effect of wood traits on decomposition microsite environment. The wood trait-decomposition results point to an important role for changes in the wood traits of dominant tree species as a driver of carbon cycling, with likely feedback to atmospheric CO(2) particularly where angiosperm species replace gymnosperms regionally. Truly worldwide upscaling of our results will require further site-based multi-species wood trait and decomposition data, particularly from low-latitude ecosystems. PMID:19016827

Weedon, James T; Cornwell, William K; Cornelissen, Johannes H C; Zanne, Amy E; Wirth, Christian; Coomes, David A



A time-calibrated species tree of Crocodylia reveals a recent radiation of the true crocodiles.  


True crocodiles (Crocodylus) are the most broadly distributed, ecologically diverse, and species-rich crocodylian genus, comprising about half of extant crocodylian diversity and exhibiting a circumtropical distribution. Crocodylus traditionally has been viewed as an ancient group of morphologically conserved species that originated in Africa prior to continental breakup. In this study, these long-held notions about the temporal and geographic origin of Crocodylus are tested using DNA sequence data of 10 loci from 76 individuals representing all 23 crocodylian species. I infer a time-calibrated species tree of all Crocodylia and estimate the spatial pattern of diversification within Crocodylus. For the first time, a fully resolved phylogenetic estimate of all Crocodylia is well-supported. The results overturn traditional views of the evolution of Crocodylus by demonstrating that the true crocodiles are not "living-fossils" that originated in Africa. Rather, Crocodylus originated from an ancestor in the tropics of the Late Miocene Indo-Pacific, and rapidly radiated and dispersed around the globe during a period marked by mass extinctions of fellow crocodylians. The findings also reveal more diversity within the genus than is recognized by current taxonomy. PMID:22023592

Oaks, Jamie R



Species-time-area and phylogenetic-time-area relationships in tropical tree communities  

PubMed Central

The species-area relationship (SAR) has proven to be one of the few strong generalities in ecology. The temporal analog of the SAR, the species-time relationship (STR), has received considerably less attention. Recent work primarily from the temperate zone has aimed to merge the SAR and the STR into a synthetic and unified species-time-area relationship (STAR) as originally envisioned by Preston (1960). Here we test this framework using two tropical tree communities and extend it by deriving a phylogenetic-time-area relationship (PTAR). The work finds some support for Preston's prediction that diversity-time relationships, both species and phylogenetic, are sensitive to the spatial scale of the sampling. Contrary to the Preston's predictions we find a decoupling of diversity-area and diversity-time relationships in both forests as the time period used to quantify the diversity-area relationship changes. In particular, diversity-area and diversity-time relationships are positively correlated using the initial census to quantify the diversity-area relationship, but weakly or even negatively correlated when using the most recent census. Thus, diversity-area relationships could forecast the temporal accumulation of biodiversity of the forests, but they failed to “back-cast” the temporal accumulation of biodiversity suggesting a decoupling of space and time.

Swenson, Nathan G; Mi, Xiangcheng; Kress, W John; Thompson, Jill; Uriarte, Maria; Zimmerman, Jess K



Leaf respiratory acclimation to climate: comparisons among boreal and temperate tree species along a latitudinal transect.  


In common gardens along an ?900 km latitudinal transect through Wisconsin and Illinois, U.S.A., tree species typical of boreal and temperate forests were compared with respect to the nature and magnitude of leaf respiratory acclimation to contrasting climates. The boreal representatives were trembling aspen (Populus tremuloides Michx.) and paper birch (Betula papyrifera Marsh.), while the temperate species were eastern cottonwood (Populus deltoides Bartr ex. Marsh var. deltoides) and sweetgum (Liquidambar styraciflua L.). Assessments were conducted on seedlings grown from seed sources collected near southern and northern range boundaries, respectively. Nighttime rates of leaf dark respiration (R(d)) at common temperatures, as well as R(d)'s short-term temperature sensitivity (energy of activation, E(o)), were assessed for all species and gardens twice during a growing season. Little evidence of R(d) thermal acclimation was observed, despite a 12 °C range in average air temperature across gardens. Instead, R(d) variation at warm temperatures was linked most closely with prior leaf photosynthetic performance, while R(d) variation at cooler temperatures was most strongly related to leaf nitrogen concentration. Moreover, E(o) differences across species and gardens appeared to stem from the somewhat independent limitations on warm versus cool R(d). Based on this construct, an empirical model relying on R(d) estimates from leaf photosynthesis and nitrogen concentration explained 55% of the observed E(o) variation. PMID:21990024

Dillaway, Dylan N; Kruger, Eric L



Unrestricted quality of seeds in European broad-leaved tree species growing at the cold boundary of their distribution  

PubMed Central

Background and Aims The low-temperature range limit of tree species may be determined by their ability to produce and disperse viable seeds. Biological processes such as flowering, pollen transfer, pollen tube growth, fertilization, embryogenesis and seed maturation are expected to be affected by cold temperatures. The aim of this study was to assess the quality of seeds of nine broad-leaved tree species close to their elevational limit. Methods We studied nine, mostly widely distributed, European broad-leaved tree species in the genera Acer, Fagus, Fraxinus, Ilex, Laburnum, Quercus, Sorbus and Tilia. For each species, seeds were collected from stands close to optimal growth conditions (low elevation) and from marginal stands (highest elevation), replicated in two regions in the Swiss Alps. Measurements included seed weight, seed size, storage tissue quality, seed viability and germination success. Key Results All species examined produced a lot of viable seeds at their current high-elevation range limit during a summer ranked ‘normal’ by long-term temperature records. Low- and high-elevation seed sources showed hardly any trait differences. The concentration of non-structural carbohydrates tended to be higher at high elevation. Additionally, in one species, Sorbus aucuparia, all measured traits showed significantly higher seed quality in high-elevation seed sources. Conclusions For the broad-leaved tree taxa studied, the results are not in agreement with the hypothesis of reduced quality of seeds in trees at their high-elevation range limits. Under the current climatic conditions, seed quality does not constitute a serious constraint in the reproduction of these broad-leaved tree species at their high-elevation limit.

Kollas, C.; Vitasse, Y.; Randin, C. F.; Hoch, G.; Korner, C.



Flavylium chromophores as species markers for dragon's blood resins from Dracaena and Daemonorops trees.  


A simple and rapid liquid chromatographic method with diode-array UV-vis spectrophotometric detection has been developed for the authentication of dragon's blood resins from Dracaena and Daemonorops trees. Using this method it was discovered that the flavylium chromophores, which contribute to the red colour of these resins, differ among the species and could be used as markers to differentiate among species. A study of parameters, such as time of extraction, proportion of MeOH and pH, was undertaken to optimise the extraction of the flavyliums. This method was then used to make extracts from samples of dragon's blood resin obtained from material of known provenance. From the samples analysed 7,6-dihydroxy-5-methoxyflavylium (dracorhodin), 7,4'-dihydroxy-5-methoxyflavylium (dracoflavylium) and 7,4'-dihydroxyflavylium were selected as species markers for Daemonorops spp., Dracaena draco and Dracaena cinnabari, respectively. The chromatograms from these samples were used to build an HPLC-DAD database. The ability to discriminate among species of dragon's blood using the single marker compounds was compared with a principal components analysis of the chromatograms in the HPLC-DAD database. The results from the HPLC-DAD method based on the presence of these flavylium markers was unequivocal. The HPLC-DAD method was subsequently applied to 37 samples of dragon blood resins from the historical samples in the Economic Botany Collection, Royal Botanic Gardens, Kew. The method identified anomalies in how samples in this collection had been labelled. It is clear that the method can be used to evaluate the provenance of samples used in different areas of cultural heritage. It also could be used to monitor the trade of endangered species of dragon's blood and the species being used in complex formulations of traditional Chinese medicine. PMID:18817913

Sousa, Micaela M; Melo, Maria J; Parola, A Jorge; Seixas de Melo, J Sérgio; Catarino, Fernando; Pina, Fernando; Cook, Frances E M; Simmonds, Monique S J; Lopes, João A



Canopy gaps decrease microbial densities and disease risk for a shade-intolerant tree species  

NASA Astrophysics Data System (ADS)

Canopy disturbances such as windthrow events have obvious impacts on forest structure and composition aboveground, but changes in soil microbial communities and the consequences of these changes are less understood. We characterized the densities of a soil-borne pathogenic oomycete ( Pythium) and a common saprotrophic zygomycete ( Mortierella) in nine pairs of forest gaps created by windthrows and adjacent forest understories. We determined the levels of Pythium necessary to cause disease by performing pathogenicity experiments using two Pythium species, a range of Pythium densities, and two common tree species ( Acer rubrum and Prunus serotina) from the study sites. Three years post-disturbance, densities of Mortierella remained suppressed in soil from forest gaps compared to levels in intact forest understories while varying across sites and sampling dates. Pythium were infrequently detected likely because of soil handling effects. Expression of disease symptoms increased with increasing inoculum density for seedlings of P. serotina with each Pythium spp. having a similar effect on this species. Conversely, A. rubrum appeared resistant to the two species of Pythium. These results suggest that Pythium densities at sites where they were detected are sufficient to cause disease and possibly affect establishment of susceptible species like P. serotina. Because early seral environments have lower loads of the saprotrophic Mortierella, pathogen loads may follow a similar pattern, causing susceptible species to establish more frequently in those habitats than in late-seral forests. Forest disturbances that alter the disease landscape may provide an additional mechanism for explaining succession of temperate forests in addition to the shade-tolerance paradigm.

Reinhart, Kurt O.; Royo, Alejandro A.; Kageyama, Stacie A.; Clay, Keith



Species richness of herbivorous insects on Nothofagus trees in South America and New Zealand: The importance of chemical attributes of the host  

Microsoft Academic Search

Several studies have evaluated the relative contribution of various host-plant attributes to the species richness of the associated insect herbivores, with and without the inclusion of the phylogeny of the host species for Northern hemisphere trees. In general these studies reached the same conclusion: tree availability (range and abundance) was a good predictor of insect species richness, although chemical attributes

Blas Lavandero; Antonieta Labra; Claudio C. Ramírez; Hermann M. Niemeyer; Eduardo Fuentes-Contreras



Differential sectoriality in long-distance transport in temperate tree species: evidence from dye flow, 15 N transport, and vessel element pitting  

Microsoft Academic Search

The capture of patchily distributed nutrients by tree roots has received extensive research, but the fate of those nutrients has not. We performed experiments to determine if nutrient transport within tree species is preferentially transported from specific roots to specific branches. Saplings of five species with contrasting growth requirements were examined: two Betula species ( B. papyrifera and B. lenta),

Colin M. Orians; Margret M. I. van Vuuren; Nancy L. Harris; Benjamin A. Babst; George S. Ellmore



Impacts of repeated fuel reduction burning on tree growth, mortality and recruitment in mixed species eucalypt forests of southeast Queensland, Australia  

Microsoft Academic Search

The long-term effects of repeated prescribed burning on diameter growth of trees in mixed species dry and wet sclerophyll forest sites in southeast Queensland, Australia were assessed. In addition, fire effects on tree mortality and recruitment in the wet sclerophyll site were evaluated. The results show that growth responses of species to fire were variable. Nevertheless, for most species, recurrent

Danilo F Guinto; Alan P. N House; Zhi Hong Xu; Paul G Saffigna



Volatile profile differences and the associated Sirex noctilio activity in two host tree species in the Northeastern United States.  


Sirex noctilio females are known to be attracted to stem sections of stressed pine trees for oviposition. The volatile profiles and attractiveness of Eastern white pine (Pinus strobus) and two chemotypes of Scots pine (P. sylvestris) were compared after stem injection with herbicide. In general, trap captures on herbicide-treated trees were higher than on controls. The high-carene chemotype of Scots pine captured the highest numbers of females, followed by the low-carene chemotype, and finally the Eastern white pine. Herbicide-treated trees of both species emitted larger quantities of volatiles than the controls. The herbicide treatment induced higher volatile emission rates in the Scots pine chemotypes than in white pine, although there was no difference between the two chemotypes. However, qualitative differences were found between the volatile profiles of the two species as well as between the two Scots pine chemotypes, which could account for the differential attractiveness of the species and chemotypes tested. PMID:22359190

Böröczky, Katalin; Zylstra, Kelley E; McCartney, Nathaniel B; Mastro, Victor C; Tumlinson, James H



Using Data From Seed-Dispersal Modelling to Manage Invasive Tree Species: The Example of Fraxinus pennsylvanica Marshall in Europe  

NASA Astrophysics Data System (ADS)

Management strategies to control invasive species need information about dispersal distances to predict establishment potential. Fraxinus pennsylvanica is a North American anemochorous tree species that is invasive in many Central European floodplain forests. To predict seed-dispersal potential, the stochastic model WaldStat was used, which enables different options for directionality (isotropic and anisotropic) to be simulated. In this article, we (1) show empirical results of fructification and seed dispersal for this tree species. The model predicts approximately 250,000 seeds for one F. pennsylvanica tree. These results were used to (2) calculate species-specific dispersal distances and effects of wind direction. To consider the influence of wind on dispersal potential of the tree species, long-distance dispersal (LDD [95th percentile dispersal distance]) was calculated. Mean dispersal distances varied between 47 and 66 m. LDD values modelled along the main wind direction ranged from 60 to 150 m. Seed production, dispersal distance, and direction data were (3) incorporated into theoretical management scenarios for forest ecosystems. Finally (4), we discuss management options and the practical relevance of model scenarios in relation to the accuracy of spatial dispersal predictions. Further analyses should be focused on possible, well-adapted management concepts at stand level that could restrict the potential spread of invasive species.

Schmiedel, Doreen; Huth, Franka; Wagner, Sven



Using Data From Seed-Dispersal Modelling to Manage Invasive Tree Species: The Example of Fraxinus pennsylvanica Marshall in Europe.  


Management strategies to control invasive species need information about dispersal distances to predict establishment potential. Fraxinus pennsylvanica is a North American anemochorous tree species that is invasive in many Central European floodplain forests. To predict seed-dispersal potential, the stochastic model WaldStat was used, which enables different options for directionality (isotropic and anisotropic) to be simulated. In this article, we (1) show empirical results of fructification and seed dispersal for this tree species. The model predicts approximately 250,000 seeds for one F. pennsylvanica tree. These results were used to (2) calculate species-specific dispersal distances and effects of wind direction. To consider the influence of wind on dispersal potential of the tree species, long-distance dispersal (LDD [95th percentile dispersal distance]) was calculated. Mean dispersal distances varied between 47 and 66 m. LDD values modelled along the main wind direction ranged from 60 to 150 m. Seed production, dispersal distance, and direction data were (3) incorporated into theoretical management scenarios for forest ecosystems. Finally (4), we discuss management options and the practical relevance of model scenarios in relation to the accuracy of spatial dispersal predictions. Further analyses should be focused on possible, well-adapted management concepts at stand level that could restrict the potential spread of invasive species. PMID:23974901

Schmiedel, Doreen; Huth, Franka; Wagner, Sven



Heterogeneity of net precipitation due to tree species and edge effect in a semi arid cloud forest in Dhofar, Oman  

NASA Astrophysics Data System (ADS)

The cloud forests of the Dhofar mountains in Oman are one of few water limited seasonal cloud forests in the world. Because of the dry conditions (annual rainfall is only 114-252 mm depending on the location), cloud water interception by tree canopies (horizontal precipitation) is believed to play a major role for survival of the forest. Being the only green belt in the region, these ecosystems are under considerable pressure from animal feeding on tree canopies. In order to protect the Dhofar cloud forest from overgrazing and degradation a number of fenced forest enclosures have been established. Many of the originally established enclosures, however, did not survive and degraded similar to the enclosure surroundings. Our research focuses on the distribution of net precipitation (total water received below the tree canopies), as a function of throughfall, stemflow, and, horizontal precipitation within one of the few successful forest enclosures at Tawi Attair. Based on intensive measurements of throughfall, stemflow, fog, and rainfall water our work shows that the heterogeneity of net precipitation is linked to tree species and tree positioning within the enclosure. We demonstrate the contribution of both stemflow and throughfall for two different tree species, Pithicellobium dulce and Leucaenia leucacephala, as well as for different sectors within the enclosure. For stemflow results show significantly higher amounts for trees situated at the enclosure fence as well as significant differences between the two tree species. For throughfall the results were less pronounced but still show significant differences between different sectors. Generally, stemflow was considerable in all sectors, and is believed to contribute significantly to ground water recharge in this region. The work contributes to the understanding of these water limited seasonal cloud forests and to the future design of successful forest enclosures in the Dhofar mountains.

Bawain, Abdullah; Friesen, Jan; Hildebrandt, Anke



Role of bioinoculants and organic fertilizers in fodder production and quality of leguminous tree species.  


The comparative effect of dual inoculation of native N fixer (Rhizobium) and AM fungi consortia with different organic fertilizers (vermicompost and farm yard manure) on fodder production and quality of two leguminous tree species (Leucaena leucocephala (Lam) de. Wit. and Sesbania sesban (L.) Merr.) in silvopastoral system and their impact on the fodder production of un-inoculated Panicum maximum Jacq. under cut and carry system. After three years of plantation maximum tree survival was in L. leucocephala in all the treatments in comparison to S. sesban while fodder production was more in S. sesban for initial two years and in third year it accelerated in L. leucocephala. Dual inoculation with vermicompost significantly improved fodder production, fodder quality and rhizosphere microflora in L. leucocephala but in S. sesban dual inoculation was at par with single inoculation of N fixer, AM fungi and control (without inoculation). The grass production was higher with L. leucocephala for two years while in third year it was more with S. sesban. The association of Rhizobium with AM fungi in L. leucocephala was better than in S. sesban. PMID:21888233

Mishra, Seema; Sharma, Satyawati; Vasudevan, Padma



Multiple evolutionary processes drive the patterns of genetic differentiation in a forest tree species complex  

PubMed Central

Forest trees frequently form species complexes, complicating taxonomic classification and gene pool management. This is certainly the case in Eucalyptus, and well exemplified by the Eucalyptus globulus complex. This ecologically and economically significant complex comprises four taxa (sspp. bicostata, globulus, maidenii, pseudoglobulus) that are geographically and morphologically distinct, but linked by extensive “intergrade” populations. To resolve their genetic affinities, nine microsatellites were used to genotype 1200 trees from throughout the natural range of the complex in Australia, representing 33 morphological core and intergrade populations. There was significant spatial genetic structure (FST = 0.10), but variation was continuous. High genetic diversity in southern ssp. maidenii indicates that this region is the center of origin. Genetic diversity decreases and population differentiation increases with distance from this area, suggesting that drift is a major evolutionary process. Many of the intergrade populations, along with other populations morphologically classified as ssp. pseudoglobulus or ssp. globulus, belong to a “cryptic genetic entity” that is genetically and geographically intermediate between core ssp. bicostata, ssp. maidenii, and ssp. globulus. Geography, rather than morphology, therefore, is the best predictor of overall genetic affinities within the complex and should be used to classify germplasm into management units for conservation and breeding purposes.

Jones, Rebecca C; Steane, Dorothy A; Lavery, Martyn; Vaillancourt, Rene E; Potts, Brad M



Multiple evolutionary processes drive the patterns of genetic differentiation in a forest tree species complex.  


Forest trees frequently form species complexes, complicating taxonomic classification and gene pool management. This is certainly the case in Eucalyptus, and well exemplified by the Eucalyptus globulus complex. This ecologically and economically significant complex comprises four taxa (sspp. bicostata, globulus, maidenii, pseudoglobulus) that are geographically and morphologically distinct, but linked by extensive "intergrade" populations. To resolve their genetic affinities, nine microsatellites were used to genotype 1200 trees from throughout the natural range of the complex in Australia, representing 33 morphological core and intergrade populations. There was significant spatial genetic structure (F(ST) = 0.10), but variation was continuous. High genetic diversity in southern ssp. maidenii indicates that this region is the center of origin. Genetic diversity decreases and population differentiation increases with distance from this area, suggesting that drift is a major evolutionary process. Many of the intergrade populations, along with other populations morphologically classified as ssp. pseudoglobulus or ssp. globulus, belong to a "cryptic genetic entity" that is genetically and geographically intermediate between core ssp. bicostata, ssp. maidenii, and ssp. globulus. Geography, rather than morphology, therefore, is the best predictor of overall genetic affinities within the complex and should be used to classify germplasm into management units for conservation and breeding purposes. PMID:23403692

Jones, Rebecca C; Steane, Dorothy A; Lavery, Martyn; Vaillancourt, René E; Potts, Brad M



Elevated night-time temperatures increase growth in seedlings of two tropical pioneer tree species.  


Increased night-time temperatures, through their influence on dark respiration, have been implicated as a reason behind decreasing growth rates in tropical trees in the face of contemporary climate change. Seedlings of two neo-tropical tree species (Ficus insipida and Ochroma pyramidale) were grown in controlled-environment chambers at a constant daytime temperature (33°C) and a range of increasing night-time temperatures (22, 25, 28, 31°C) for between 39 d and 54 d. Temperature regimes were selected to represent a realistic baseline condition for lowland Panama, and a rise in night-time temperatures far in excess of those predicted for Central America in the coming decades. Experiments were complemented by an outdoor open-top chamber study in which night-time temperatures were elevated by 2.4°C above ambient. Increasing night-time temperatures resulted in > 2-fold increase in biomass accumulation in growth-chamber studies despite an increase in leaf-level dark respiration. Similar trends were seen in open-top chambers, in which elevated night-time temperatures resulted in stimulation of growth. These findings challenge simplistic considerations of photosynthesis-directed growth, highlighting the role of temperature-dependent night-time processes, including respiration and leaf development as drivers of plant performance in the tropics. PMID:23278464

Cheesman, Alexander W; Winter, Klaus



21 CFR 866.2300 - Multipurpose culture medium.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Multipurpose culture medium. 866.2300 Section 866.2300 Food...Devices § 866.2300 Multipurpose culture medium. (a) Identification. A multipurpose culture medium is a device that consists...



Partitioning the factors of spatial variation in regeneration density of shade-tolerant tree species.  


Understanding coexistence of highly shade-tolerant tree species is a longstanding challenge for forest ecologists. A conceptual model for the coexistence of sugar maple (Acer saccharum) and American beech (Fagus grandibfolia) has been proposed, based on a low-light survival/high-light growth trade-off, which interacts with soil fertility and small-scale spatiotemporal variation in the environment. In this study, we first tested whether the spatial distribution of seedlings and saplings can be predicted by the spatiotemporal variability of light availability and soil fertility, and second, the manner in which the process of environmental filtering changes with regeneration size. We evaluate the support for this hypothesis relative to the one for a neutral model, i.e., for seed rain density predicted from the distribution of adult trees. To do so, we performed intensive sampling over 86 quadrats (5 x 5 m) in a 0.24-ha plot in a mature maple-beech community in Quebec, Canada. Maple and beech abundance, soil characteristics, light availability, and growth history (used as a proxy for spatiotemporal variation in light availability) were finely measured to model variation in sapling composition across different size classes. Results indicate that the variables selected to model species distribution do effectively change with size, but not as predicted by the conceptual model. Our results show that variability in the environment is not sufficient to differentiate these species' distributions in space. Although species differ in their spatial distribution in the small size classes, they tend to correlate at the larger size class in which recruitment occurs. Overall, the results are not supportive of a model of coexistence based on small-scale variations in the environment. We propose that, at the scale of a local stand, the lack of fit of the model could result from the high similarity of species in the range of environmental conditions encountered, and we suggest that coexistence would be stable only at larger spatial scales at which variability in the environment is greater. PMID:18959325

Gravel, Dominique; Beaudet, Marilou; Messier, Christian



Digital Representations of Tree Species Range Maps from "Atlas of United States Trees" by Elbert L. Little, Jr. (and other publications)  

NSDL National Science Digital Library

The Earth Surface Dynamics section of the USGS provides this excellent collection of graphics, depicting range maps for more than 100 common North American tree species. From Abies amabilis to Yucca brevifolia, these color maps may be viewed or downloaded (.pdf, .zip, tgz). Most of the ranges depicted here were digitized by Elbert L. Little, Jr. (USDA Forest Service) for vegetation-climate modeling studies; graphics are best viewed as downloaded files.



PubMed Central

Spatially explicit data layers of tree species assemblages, referred to as forest types or forest type groups, are a key component in large-scale assessments of forest sustainability, biodiversity, timber biomass, carbon sinks and forest health monitoring. This paper explores the utility of coupling georeferenced national forest inventory (NFI) data with readily available and spatially complete environmental predictor variables through spatially-varying multinomial logistic regression models to predict forest type groups across large forested landscapes. These models exploit underlying spatial associations within the NFI plot array and the spatially-varying impact of predictor variables to improve the accuracy of forest type group predictions. The richness of these models incurs onerous computational burdens and we discuss dimension reducing spatial processes that retain the richness in modeling. We illustrate using NFI data from Michigan, USA, where we provide a comprehensive analysis of this large study area and demonstrate improved prediction with associated measures of uncertainty.

Banerjee, Sudipto; McRoberts, Ronald E.



[Effects of NaCl stress on the seedling growth and K(+)- and Na(+) -allocation of four leguminous tree species].  


Taking the pot-cultured seedlings of four leguminous tree species (Albizia julibrissin, Robinia pseudoacacia, Sophora japonica, and Gleditsia sinensis) as test materials, this paper studied their growth indices, critical salt concentration (C50), and K+ and Na+ allocation under different levels of NaCl stress, aimed to understand the difference of test tree species in salt tolerance. NaCl stress inhibited the seedling growth of the tree species. Under NaCl stress, the dry matter accumulation decreased, while the root/shoot ratio increased, especially for A. julibrissin and G. sinensis. Quadratic regression analysis showed that the C50 of A. julibrissin, R. pseudoacacia, S. japonica, and G. sinensis was 3.0 per thousand, 5.0 per thousand, 4.5 per thousand, and 3.9 per thousand, respectively, i.e., the salt tolerance of the four tree species was in the order of R. pseudoacacia > S. japonica > G. sinensis > A. julibrissin. In the root, stem, and leaf of the four tree species seedlings, the Na+ content increased with the increase of NaCl stress, while the K+ content (except in the root of A. julibrissin) decreased after an initial increase, resulting in a larger difference in the K+/Na+ ratio in the organs. Under the same NaCl stress, the allocation of Na+ in different organs of the four tree species seedlings decreased in the order of root>stem>leaf, while that of K+ differed with tree species and NaCl stress, and leaf was the main storage organ for K+. The K+/Na+ ratio in different organs decreased in the sequence of leaf>stem>root. R. pseudoacacia under NaCl stress accumulated more K+ and less Na+ in stem and leaf, and had higher K+/Na+ ratio in all organs and higher dry mass, being assessed to be more salt-tolerant. In contrast, A. julibrissin under high NaCl stress accumulated more Na+ in stem and leaf, and had a lower K+/Na+ ratio in all organs and lower dry mass, being evaluated to be lesser salt-tolerant. The K+ accumulation in seedling stem and leaf and the Na+ retention in seedling root could be the main reasons for the salt tolerance of leguminous tree species under NaCl stress. PMID:21812288

Mo, Hai-Bo; Yin, Yun-Long; Lu, Zhi-Guo; Wei, Xiu-Jun; Xu, Jian-Hua



Contrasting relationships between species diversity and genetic diversity in natural and disturbed forest tree communities.  


• This study aimed to reveal species-genetic diversity correlations (SGDCs) and their underlying mechanisms in natural and disturbed forests. • A community survey and molecular analyses were carried out to compare species diversity (SD), the genetic diversity of the dominant tree species Euptelea pleiospermum (GD), the altitudinal patterns of SD and GD, SGDC, genetic differentiation (F(ST) ), community divergence (F(ST) -C), effective population size (N(e) ), and recent migration rate between mountain riparian forests along the Yandu (natural) and Nan (disturbed) rivers. • In natural forests, both SD and GD showed a unimodal altitudinal pattern and GD was positively correlated with SD, whereas a unimodal pattern and positive SGDC were not found in the disturbed forests. SD and F(ST) at the natural sites were higher than those at the disturbed sites. However, there were no significant differences in GD, F(ST) -C, N(e) or recent migration rate between the natural and disturbed sites. • A correlation between the patterns of SD and GD along a geographical gradient (e.g. altitude) is an important driver of positive SGDC. The absence of positive SGDC in the disturbed forests may result from reduced SD but unaffected GD, indicating nonparallel changes in SD and GD. This study furthermore cautions against generalizations about changes in SD and GD following disturbance. PMID:22106986

Wei, Xinzeng; Jiang, Mingxi



Extractives content in cooperage oak wood during natural seasoning and toasting; influence of tree species, geographic location, and single-tree effects.  


The chemical composition of cooperage oak wood is highly variable, depending upon the tree species (Quercus robur L. versus Quercus petraea Liebl.), its geographic location, and the single-tree effect. In the process of cask-making, natural seasoning and toasting contribute strongly to the modification of the oak wood chemical composition and therefore influence wine cooperaging. HPLC and GC quantification of ellagitannins and volatile compounds such as whiskey-lactones, eugenol, and vanillin over a sample set of 61 pedunculate oaks and 72 sessile oaks originating from six different forests showed that natural drying leads to a decrease of the ellagitannins and total extractives content level and a quasi constant level of the volatile compounds. Toasting (medium type) drastically enhanced the loss of ellagitannins and the gain in volatile compounds. Statistical treatment showed that the species effect remained significant throughout the process of drying and toasting, but not the provenance. The poor correlation with ring width of extractives levels measured on fresh timber remained unchanged as did the single-tree effect, with high variability found for all chemical parameters. These results provide further evidence that cooperage oak selection should not be based solely on the wood grain or the provenance but rather on a species-provenance combination. PMID:12358465

Doussot, Franck; De Jéso, Bernard; Quideau, Stéphane; Pardon, Patrick



Genetic structure of tree and shrubby species among anthropogenic edges, natural edges, and interior of an atlantic forest fragment.  


Two species, Psychotria tenuinervis (shrub, Rubiaceae) and Guarea guidonia (tree, Meliaceae), were used as models to compare the genetic structure of tree and shrubby species among natural edges, anthropogenic edges, and a fragment interior. There were significant differences between two genetic markers. For isozymes, P. tenuinervis presented greater heterozygosity (expected and observed) and a higher percentage of polymorphic loci and median number of alleles than G. guidonia. For microsatellites, there was no difference in genetic variability between the species. Only P. tenuinervis, for isozymes, showed differences in genetic variability among the three habitats. There was no genetic structure (F (ST) < 0.05) among habitats in both plant species for both genetic markers. Isozymes showed great endogamy for both plant species, but not microsatellites. The forest fragmentation may have negative effects on both spatial (among edges and interior) and temporal genetic variability. PMID:19941054

Ramos, Flavio Nunes; de Lima, Paula Feliciano; Zucchi, Maria Imaculada; Colombo, Carlos Augusto; Solferini, Vera Nisaka



Stem water storage in five coexisting temperate broad-leaved tree species: significance, temporal dynamics and dependence on tree functional traits.  


The functional role of internal water storage is increasingly well understood in tropical trees and conifers, while temperate broad-leaved trees have only rarely been studied. We examined the magnitude and dynamics of the use of stem water reserves for transpiration in five coexisting temperate broad-leaved trees with largely different morphology and physiology (genera Fagus, Fraxinus, Tilia, Carpinus and Acer). We expected that differences in water storage patterns would mostly reflect species differences in wood anatomy (ring vs. diffuse-porous) and wood density. Sap flux density was recorded synchronously at five positions along the root-to-branch flow path of mature trees (roots, three stem positions and branches) with high temporal resolution (2 min) and related to stem radius changes recorded with electronic point dendrometers. The daily amount of stored stem water withdrawn for transpiration was estimated by comparing the integrated flow at stem base and stem top. The temporal coincidence of flows at different positions and apparent time lags were examined by cross-correlation analysis. Our results confirm that internal water stores play an important role in the four diffuse-porous species with estimated 5-12 kg day(-1) being withdrawn on average in 25-28 m tall trees representing 10-22% of daily transpiration; in contrast, only 0.5-2.0 kg day(-1) was withdrawn in ring-porous Fraxinus. Wood density had a large influence on storage; sapwood area (diffuse- vs. ring-porous) may be another influential factor but its effect was not significant. Across the five species, the length of the time lag in flow at stem top and stem base was positively related to the size of stem storage. The stem stores were mostly exhausted when the soil matrix potential dropped below -0.1 MPa and daily mean vapor pressure deficit exceeded 3-5 hPa. We conclude that stem storage is an important factor improving the water balance of diffuse-porous temperate broad-leaved trees in moist periods, while it may be of low relevance in dry periods and in ring-porous species. PMID:23999137

Köcher, Paul; Horna, Viviana; Leuschner, Christoph



Biosafety in Populus spp. and other forest trees: from non-native species to taxa derived from traditional breeding and genetic engineering  

Microsoft Academic Search

Forest trees are fundamental components of our environment, mainly due to their long lifetime and important role in forest ecology. In the past, some non-native tree species and taxa from traditional breeding have induced severe environmental impacts such as biological invasion, changes in the ‘gene pool’, and spread of diseases in forestry. Genetically modified trees obtained in different research groups

Hans Hoenicka; Matthias Fladung



Habitat associations of saproxylic beetles in the southeastern United States: A comparison of forest types, tree species and wood postures.  

SciTech Connect

Saproxylic beetles are highly sensitive to forest management practices that reduce the abundance and variety of dead wood. However, this diverse fauna continues to receive little attention in the southeastern United States even though this region supports some of the most diverse, productive and intensively managed forests in North America. In this replicated three-way factorial experiment, we investigated the habitat associations of saproxylic beetles on the coastal plain of South Carolina. The factors of interest were forest type (upland pine-dominated vs. bottomland hardwood), tree species (Quercus nigra L., Pinustaeda L. and Liquidambar styraciflua L.) and wood posture (standing and downed dead wood, i.e., snags and logs). Wood samples were taken at four positions along each log and snag (lower bole,middle bole, upper bole and crown) _11 months after the trees were killed and placed in rearing bags to collect emerging beetles. Overall, 33,457 specimens from 52 families and _250 species emerged. Based on an analysis of covariance, with surface area and bark coverage as covariates, saproxylic beetle species richness differed significantly between forest types as well as between wood postures. There were no significant interactions. Species richness was significantly higher in the upland pine-dominated stand than the bottomland hardwood forest, possibly due to higher light exposure and temperature in upland forests. Although L. styraciflua yielded more beetle species (152) than either Q. nigra (122) or P. taeda (125), there were no significant differences in species richness among tree species. There were also no relationships evident between relative tree abundance and observed or expected beetle species richness. Significantly more beetle species emerged from logs than from snags. However snags had a distinct fauna including several potential canopy specialists. Our results suggest that conservation practices that retain or create entire snags as opposed to high stumps or logs alone will most greatly benefit saproxylic beetles in southeastern forests.

Ulyshen, Michael, D.; Hanula, James, L.



Compartmentalization of Decayed Wood Associated with 'Armillaria mellea' in Several Tree Species.  

National Technical Information Service (NTIS)

Decayed wood associated with Armillaria mellea was compartmentalized according to the CODIT (Compartmentalization Of Decay In Trees) model. Compartmentalization in the sapwood began after the tree walled off the area of dead cambium associated with the in...

A. L. Shigo J. T. Tippett



Species-specific patterns of hydraulic lift in co-occurring adult trees and grasses in a sandhill community.  


Plants can significantly affect ecosystem water balance by hydraulic redistribution (HR) from dry to wet soil layers via roots (also called hydraulic lift, HL, when the redistribution is from deep to shallow soil). However, the information on how co-occurring species in natural habitats differ in HL ability is insufficient. In a field study, we compared HL ability of four tree species (including three congeneric oak species) and two C4 bunch grass species that co-occur in subxeric habitats of fall-line sandhills in southeastern USA. Soil water potentials (psi(s)) were recorded hourly for 3 years both in large chambers that isolated roots for each species and outside the chambers. Outside of root chambers, soil drying occurred periodically in the top 25 cm and corresponded with lack of precipitation during the summer growing season. Soil moisture was continuously available at a 1 m depth. HL activity was observed in three of the tree species, with greater frequency for Pinus palustris than for Quercus laevis and Q. incana. The fourth tree species Q. margaretta did not exhibit HL activity even though it experienced a similar psi(s) gradient. For the C4 bunch grasses, Aristida stricta exhibited a small amount of HL activity, but Schizachyrium scoparium did not. The capacity for HL activity may be linked to the species ecological distribution. The four species that exhibited HL activity in this subxeric habitat are also dominant in adjacent xeric sandhill habitats, whereas the species that did not exhibit HL are scarcely found in the xeric areas. This is consistent with other studies that found greater fine root survival in dry soil for the four xeric species exhibiting HL activity. The differential ability of these species to redistribute water from the deep soil to the rapidly drying shallow soil likely has a strong effect on the water balance of sandhill plant communities, and is likely linked to their differential distribution across edaphic gradients. PMID:14689298

Espeleta, J F; West, J B; Donovan, L A



Identification, measurement and interpretation of tree rings in woody species from mediterranean climates  

Microsoft Academic Search

We review the literature dealing with mediterranean climate, vegetation, phenology and ecophysiology relevant to the understanding of tree-ring formation in mediterranean regions. Tree rings have been used extensively in temperate regions to reconstruct responses of forests to past environmental changes. In mediterranean regions, studies of tree rings are scarce, despite their potential for understanding and predicting the eects of global




OH reactivity measurements from Boreal tree species in a plant chamber  

NASA Astrophysics Data System (ADS)

Boreal forest covers a large area (ca. 15 million km2) comparable in size to the Tropical rain forest (ca. 17 million km2). The vegetation in Boreal regions is typically conifer forest which is known to emit significant amounts of biogenic volatile organic compounds (BVOCS), such as monoterpenes, sesquiterpenes, methanol and acetone. Many of these organic chemicals react rapidly with hydroxyl (OH) radicals to produce aerosols or secondary pollutants such as ozone. The total effect of the emitted species on the OH radical can be determined by measuring the total OH reactivity directly. Therefore a new measurement method was recently devised (Sinha et al., 2008). The Jülich plant atmosphere chamber (JPAC) at the Forschungszentrum-Jülich was used to investigate the overall reactivity of emissions from several Boreal tree species under controlled conditions in October 2009. Vegetation, temperature and light intensities typical of the Hyytiälä measurement station in Finland were used in these experiments and the levels of CO2, humidity and NOx were controlled. In addition to the reactivity measurement, a gas chromatograph (GC), a proton transfer reaction mass spectrometer (PTRMS) and a time-of-flight PTRMS (TOF-PTRMS) were used to quantify individual organic chemicals emitted by the plants for comparison with the overall reactivity. Experiments were performed under three different conditions. 1) Lower temperatures (T=20° C) resulted in low plant emissions with no diurnal variation. The total measured OH reactivity ranged from below detection limit (3 sec-1) to 7 sec-1 during the day and overnight rose to 8-13 sec-1. 2) Higher temperatures (T=35° C) produced higher emissions of volatile organic compounds and a clear diurnal trend. Reactivity data matched well with these results rising to 30-50 sec-1 by day and during the night sinking again to 8-13 sec-1. 3) Finally a control experiment was performed without trees in the plant chamber. In this experiment, reactivity showed no nocturnal or diurnal variation and measured values remained below detection limit. Significant fractions of the diurnal reactivity could be explained by the individual VOC measurements; however, for all measured organic species we found higher emissions during periods of illumination than during periods of darkness. Also subsequent laboratory tests have eliminated interferences and influences of CO2 and water vapor concentrations as a possible explanation. The elevated nighttime values can be attributed to the presence of the plants and not to a chamber related artefact. The cause of the high nocturnal reactivity remains unexplained.

Nölscher, Anke; Custer, Thomas; Sinha, Vinayak; Kiendler-Scharr, Astrid; Kleist, Einhard; Tillmann, Ralf; Wildt, Jürgen; Williams, Jonathan



An inexpensive, multipurpose physical pendulum  

NASA Astrophysics Data System (ADS)

The pendulum is a highly versatile tool for teaching physics. Many special purpose pendula for student experiments have been described.1-4 In this paper, I describe an inexpensive, multipurpose physical pendulum that can function as both a variable gravity and ballistic pendulum. I designed the apparatus for use in a rotational dynamics unit of the AP Physics C mechanics course. The use of a bike wheel hub pivot allows for low-friction, rugged operation that yields results commensurate with those obtained with much more expensive pendula available on the market (typically $500 per unit5), placing these types of experiments within reach of the teacher on a restricted budget.

Schultz, David



Development of microsatellite markers for the endangered Neotropical tree species Tibouchina papyrus (Melastomataceae).  


We isolated and characterized 12 microsatellite loci for Tibouchina papyrus (Melastomataceae), an endangered species with narrow and disjunct range, endemics to a few localities in "cerrado rupestre" from Central Brazil. These microsatellites were obtained by sequencing of a genomic shotgun library for primer design. Leaves from 96 individuals collected in the three known local populations were genotyped using the 12 primers designed to analyze the polymorphisms at each locus. The number of alleles per locus ranged from one to six; two loci were monomorphic. Among the polymorphic loci, expected heterozygosities ranged from 0.161 to 0.714. Combined paternity exclusion probability was 0.957 and combined genetic identity (0.051) was high for studies on parentage. Tibouchina papyrus is a rare and endemic tree species of outcrop quartzite and sandstone soils, with highly isolated populations, which may have lead to the low degree of polymorphism that we detected. Also, motifs of most loci are larger than dinucleotide, which typically display lower levels of polymorphism. PMID:21365547

Telles, M P C; Peixoto, F P; Lima, J S; Resende, L V; Vianello, R P; Walter, M E M T; Collevatti, R G



Herbivory As A Driver For Biogenic Methanol Flux From North American Temperate Tree Species  

NASA Astrophysics Data System (ADS)

Ecological relationships of plants and herbivores have implications for biosphere-atmosphere interactions. For instance, plant monoterpene emission response to herbivory can significantly impact air quality /(Litvak et al. /(1999/) Ecol. Appl. 9/(4/):1147-1159/). Studies on biogenic methanol emission response to herbivory have observed significant methanol emissions directly following herbivore attack and even larger emissions 24hrs later /(Penuelas et al. /(2005/) New Phytol. 167:851-857/). We investigated gypsy moth defoliation impacts on methanol emissions in the abundant North American temperate tree species big tooth aspen Populus grandidentata. Specifically, we measured methanol emission response to herbivory on both short and long time scales at a field site in northern Michigan. Our results suggest herbivory can significantly increase methanol emissions on both short and long time scales. Unlike previous investigations, we did not observe methanol emissions 24hrs post-attack to be significantly higher than emissions detected directly following attack. When compared to mechanical wounding, herbivory did not elicit a quantitatively different methanol emission response in this species. These results suggest that herbivory in temperate forests may be an important driver for biogenic methanol flux and may therefore be helpful in improving models of methanol dynamics.

Oikawa, P.; Lerdau, M.; Mak, J.



Base-cation Cycling by Individual Tree Species in Old-growth Forests of Upper Michigan, USA  

Microsoft Academic Search

The influence of individual tree species on base-cation (Ca, Mg, K, Na) distribution and cycling was examined in sugar maple (Acer saccharum Marsh.), basswood (Tilia americana L.), and hemlock (Tsuga canadensis L.) in old-growth northern hardwood – hemlock forests on a sandy, mixed, frigid, Typic Haplorthod over two growing seasons in northwestern Michigan. Base cations in biomass, forest floor, and

Ryo Fujinuma; James Bockheim; Nick Balster




Microsoft Academic Search

The potential of 6 tree species (Leucaena leucocephala, Acacia mangium, Peltophorum pterocarpum, Pterocarpus macrocarpus, Lagerstroemia floribunda, Eucalyptus camaldulensis) for phytoremediation of Pb in sand tailings (total Pb>9850 mg kg) from KEMCO Pb mine in Kanchanaburi province, Thailand, were investigated employing a pot experiment (3 months) and field trial experiment (12 months). In pot study E. camaldulensis treated with Osmocote fertilizer

Weeradej Meeinkuirt; Phanwimol Tanhan; Prayad Pokethitiyook; Maleeya Kruatrachue; Rattanawat Chaiyarat




Technology Transfer Automated Retrieval System (TEKTRAN)

In 15-yr-old experimental plantations at La Selva Biological Station, Costa Rica, six tree species differed in their effects on soil organic carbon (SOC) sequestration and soil pH. In initial studies to identify underlying mechanisms, we measured several biochemical attributes of fine roots, senesce...


The relationship between growth and mortality for seven co-occurring tree species in the southern Appalachian Mountains  

Microsoft Academic Search

Summary 1 Slow growth is associated with high mortality risk for trees, but few data exist to assess interspecific differences in the relationship between growth and mortality. Here we compare low growth tolerance for seven co-occurring species in the southern Appa- lachian Mountains: Acer rubrum , Betula lenta , Cornus florida , Liriodendron tulipifera , Quercus prinus , Quercus rubra

Peter H. Wyckoff; James S. Clark



Species-specific patterns of hydraulic lift in co-occurring adult trees and grasses in a sandhill community  

Microsoft Academic Search

Plants can significantly affect ecosystem water balance by hydraulic redistribution (HR) from dry to wet soil layers via roots (also called hydraulic lift, HL, when the redistribution is from deep to shallow soil). However, the information on how co-occurring species in natural habitats differ in HL ability is insufficient. In a field study, we compared HL ability of four tree

J. F. Espeleta; J. B. West; L. A. Donovan



Respiration characteristics in temperate rainforest tree species differ along a long-term soil-development chronosequence  

Microsoft Academic Search

We measured the response of dark respiration (Rd) to temperature and foliage characteristics in the upper canopies of tree species in temperate rainforest communites in New Zealand along a soil chronosequence (six sites from 6 years to 120,000 years). The chronosequence provided a vegetation gradient characterised by significant changes in soil nutrition. This enabled us to examine the extent to which changes

Matthew H. Turnbull; David T. Tissue; Kevin L. Griffin; Sarah J. Richardson; Duane A. Peltzer; David Whitehead



Population structure and genetic diversity of three species of Pythium isolated from forest tree nursery soils in Oregon and Washington  

Technology Transfer Automated Retrieval System (TEKTRAN)

The genus Pythium includes some of the most important soilborne pathogens that cause damping–off and root rot of conifers, resulting in high seedling mortality in forest tree nurseries. The aim of this study was to analyze the diversity and population structure of three species of Pythium (P. irregu...


In vitro ruminal fermentation kinetics and energy utilization of three Mexican tree fodder species during the rainy and dry period  

Microsoft Academic Search

A factorial experimental design (3×2×3) was used to evaluate the effect of season of harvest and type of ruminal inoculums on in vitro ruminal fermentation kinetics and energy utilization of three browse tree foliages (Lysiloma acapulcencis, Quercus laeta and Pithecellobium dulce). Browse species were harvested during the dry season (DS) and rainy season (RS) and incubated with three different ruminal

L. M. Camacho; R. Rojo; A. Z. M. Salem; G. D. Mendoza; D. López; J. L. Tinoco; B. Albarrán; O. D. Montañez-Valdez



MODIS enhanced vegetation index predicts tree species richness across forested ecoregions in the contiguous U.S.A  

Microsoft Academic Search

With the expectation of major shifts in climate, ecologists have focused attention on developing predictive relationships between current climatic conditions and species diversity. Climatic relationships appear best defined at regional rather than local levels. In reference to tree diversity, process-based models that express gross primary production (GPP) as an integrated function of climate seem most appropriate. Since 2000, NASA's MODIS

R. H. Waring; N. C. Coops; W. Fanc; J. M. Nightingale



The influence of the development of temperate fruit tree species on the potential for their uptake of radionuclides  

Microsoft Academic Search

This paper reviews the published literature that describes the phenological development of above and below ground organs of temperate fruit trees (top fruit), particularly with respect to apple (Malus domestica). Critical information is presented which is considered appropriate in developing an understanding of the potential for top fruit species to take up radionuclide contaminants from the atmosphere and the soil.

C. J Atkinson; A. D Webster



Tree species selection for land rehabilitation in Ethiopia: from fragmented knowledge to an integrated multi-criteria decision approach  

Microsoft Academic Search

Dryland regions worldwide are increasingly suffering from losses of soil and biodiversity as a consequence of land degradation.\\u000a Integrated conservation, rehabilitation and community-based management of natural resources are therefore of vital importance.\\u000a Local planting efforts should focus on species performing a wide range of functions. Too often however, unsuitable tree species\\u000a are planted when both ecological suitability for the targeted

Bert Reubens; Clara Moeremans; Jean Poesen; Jan Nyssen; Sarah Tewoldeberhan; Steve Franzel; Jozef Deckers; Caleb Orwa; Bart Muys



Foliar Damage, Ion Content, and Mortality Rate of Five Common Roadside Tree Species Treated with Soil Applications of Magnesium Chloride  

Microsoft Academic Search

Sensitivity to magnesium chloride (MgCl2) was assessed on five common roadside tree species by maintaining soil concentrations at 0-, 400-, 800-, or 1,600-ppm chloride\\u000a via MgCl2 solution over four growing seasons. Evaluations of growth, leaf retention, foliar damage, and ion concentrations were conducted.\\u000a Water potentials were measured on two species. Foliar chloride and magnesium concentrations were positively correlated with\\u000a foliar

Betsy A. Goodrich; William R. Jacobi


Importance of seed size for the establishment of seedlings of five deciduous broad-leaved tree species  

Microsoft Academic Search

Effects of seed size and phenology on the establishment of five deciduous broad-leaved tree species were examined in deciduous woodland. Treatments included absence and presence of litter in the forest understory, a small gap, and a large gap. Seedling emergence of large-seeded speciesQuercus mongolica var.grosseserrata andAcer mono was not reduced by accumulation of litter in the forest understory, but was

Kenji Seiwa; Kihachiro Kikuzawa



JContextExplorer: a tree-based approach to facilitate cross-species genomic context comparison  

PubMed Central

Background Cross-species comparisons of gene neighborhoods (also called genomic contexts) in microbes may provide insight into determining functionally related or co-regulated sets of genes, suggest annotations of previously un-annotated genes, and help to identify horizontal gene transfer events across microbial species. Existing tools to investigate genomic contexts, however, lack features for dynamically comparing and exploring genomic regions from multiple species. As DNA sequencing technologies improve and the number of whole sequenced microbial genomes increases, a user-friendly genome context comparison platform designed for use by a broad range of users promises to satisfy a growing need in the biological community. Results Here we present JContextExplorer: a tool that organizes genomic contexts into branching diagrams. We implement several alternative context-comparison and tree rendering algorithms, and allow for easy transitioning between different clustering algorithms. To facilitate genomic context analysis, our tool implements GUI features, such as text search filtering, point-and-click interrogation of individual contexts, and genomic visualization via a multi-genome browser. We demonstrate a use case of our tool by attempting to resolve annotation ambiguities between two highly homologous yet functionally distinct genes in a set of 22 alpha and gamma proteobacteria. Conclusions JContextExplorer should enable a broad range of users to analyze and explore genomic contexts. The program has been tested on Windows, Mac, and Linux operating systems, and is implemented both as an executable JAR file and java WebStart. Program executables, source code, and documentation is available at



Impact of season, stem diameter and intensity of debarking on survival and bark re-growth pattern of medicinal tree species, Benin, West Africa  

Microsoft Academic Search

Bark is a greatly coveted non-timber forest product (NTFP). Its overexploitation from medicinal tree species threatens an essential source of medication for rural populations. Despite the relevance of bark, not much information is available on the ecological impact of bark harvesting. In Benin, West Africa, we investigated how various harvesting techniques affect the bark re-growth of 12 tree species and

Claire Delvaux; Brice Sinsin; Patrick Van Damme



Tree species effects on soil enzyme activities through effects on soil physicochemical and microbial properties in a tropical montane forest on Mt. Kinabalu, Borneo  

Microsoft Academic Search

Tree species influence on the soil mineralization process can regulate overall nutrient cycling in a forest ecosystem, which may occur through their effects on substrate quality, soil physicochemical properties and soil microbial community. We investigated tree species effects on soil enzyme activities in a tropical montane forest on Mt. Kinabalu, Borneo. Specifically, we analyzed C- and P-degrading enzyme activities, as

Masayuki Ushio; Kanehiro Kitayama; Teri C. Balser



Genetic variation in the Solanaceae fruit bearing species lulo and tree tomato revealed by Conserved Ortholog (COSII) markers.  


The Lulo or naranjilla (Solanum quitoense Lam.) and the tree tomato or tamarillo (Solanum betaceum Cav. Sendt.) are both Andean tropical fruit species with high nutritional value and the potential for becoming premium products in local and export markets. Herein, we present a report on the genetic characterization of 62 accessions of lulos (n = 32) and tree tomatoes (n = 30) through the use of PCR-based markers developed from single-copy conserved orthologous genes (COSII) in other Solanaceae (Asterid) species. We successfully PCR amplified a set of these markers for lulos (34 out of 46 initially tested) and tree tomatoes (26 out of 41) for molecular studies. Six polymorphic COSII markers were found in lulo with a total of 47 alleles and five polymorphic markers in tree tomato with a total of 39 alleles in the two populations. Further genetic analyses indicated a high population structure (with F(ST) > 0.90), which may be a result of low migration between populations, adaptation to various niches and the number of markers evaluated. We propose COSII markers as sound tools for molecular studies, conservation and the breeding of these two fruit species. PMID:21637482

Enciso-Rodríguez, Felix; Martínez, Rodrigo; Lobo, Mario; Barrero, Luz Stella



Elevated atmospheric CO? mitigated photoinhibition in a tropical tree species, Gmelina arborea.  


Effects of elevated CO? on photosynthetic CO? assimilation, PSII photochemistry and photoinhibition were investigated in the leaves of a fast growing tropical tree species, Gmelina arborea (Verbenaceae) during summer days of peak growth season under natural light. Elevated CO? had a significant effect on CO? assimilation rates and maximal efficiency of PSII photochemistry. Chlorophyll a fluorescence induction kinetics were measured to determine the influence of elevated CO? on PSII efficiency. During midday, elevated CO?-grown Gmelina showed significantly higher net photosynthesis (p<0.001) and greater F(V)/F(M) (p<0.001) than those grown under ambient CO?. The impact of elevated CO? on photosynthetic rates and Chl a fluorescence were more pronounced during midday depression where the impact of high irradiance decreased in plants grown under elevated CO? compared to ambient CO?-grown plants. Our results clearly demonstrate that decreased susceptibility to photoinhibition in elevated CO? grown plants was associated with increased accumulation of active PSII reaction centers and efficient photochemical quenching. We conclude that elevated CO? treatment resulted in easy diminution of midday photosynthetic depression. PMID:21441036

Rasineni, Girish Kumar; Guha, Anirban; Reddy, Attipalli Ramachandra



Comparison of the pyrolysis behavior of lignins from different tree species.  


Despite the increasing importance of biomass pyrolysis, little is known about the pyrolysis behavior of lignin--one of the main components of biomass--due to its structural complexity and the difficulty in its isolation. In the present study, we extracted lignins from Manchurian ash (Fraxinus mandschurica) and Mongolian Scots pine (Pinus sylvestris var. mongolica) using the Bjorkman procedure, which has little effect on the structure of lignin. Fourier transform infrared (FTIR) spectrometry was used to characterize the microstructure of the Bjorkman lignins, i.e., milled wood lignins (MWLs), from the different tree species. The pyrolysis characteristics of MWLs were investigated using a thermogravimetric analyzer, and the release of the main volatile and gaseous products of pyrolysis were detected by FTIR spectroscopy. During the pyrolysis process, MWLs underwent thermo-degradation over a wide temperature range. Manchurian ash MWL showed a much higher thermal degradation rate than Mongolian Scots pine MWL in the temperature range from 290-430 degrees C. High residue yields were achieved at 37 wt.% for Mongolian Scots pine MWL and 26 wt.% for Manchurian ash MWL. In order to further investigate the mechanisms of lignin pyrolysis, we also analyzed the FTIR profiles for the main pyrolysis products (CO(2), CO, methane, methanol, phenols and formaldehyde) and investigated the variation in pyrolysis products between the different MWLs. PMID:19393737

Wang, Shurong; Wang, Kaige; Liu, Qian; Gu, Yueling; Luo, Zhongyang; Cen, Kefa; Fransson, Torsten



Assessing the potential for rhizoremediation of PCB contaminated soils in northern regions using native tree species.  


Rhizosphere bioremediation of polychlorinated biphenyls (PCBs) offers a potentially inexpensive approach to remediating contaminated soils that is particularly attractive in remote regions including the Arctic. We assessed the abilities of two tree species native to Alaska, Salix alaxensis (felt-leaf willow) and Picea glauca (white spruce), to promote microbial biodegradation of PCBs via the release of phytochemicals upon fine root death. Crushed fine roots, biphenyl (PCB analogue) or salicylate (willow secondary compound) were added to microcosms containing soil spiked with PCBs and resultant PCB disappearance, soil toxicity and microbial community changes were examined. After 180d, soil treated with willow root crushates showed a significantly greater PCB loss than untreated soils for some PCB congeners, including the toxic congeners, PCB 77, 105 and 169, and showed a similar PCB loss pattern (in both extent of degradation and congeners degraded) to biphenyl-treated microcosms. Neither P. glauca (white spruce) roots nor salicylate enhanced PCB loss, indicating that biostimulation is plant species specific and was not mediated by salicylate. Soil toxicity assessed using the Microtox bioassay indicated that the willow treatment resulted in a less toxic soil environment. Molecular microbial community analyses indicated that biphenyl and salicylate promoted shifts in microbial community structure and composition that differed distinctly from each other and from the crushed root treatments. The biphenyl utilizing bacterium, Cupriavidus spp. was isolated from the soil. The findings suggest that S. alaxensis may be an effective plant for rhizoremediation by altering microbial community structure, enhancing the loss of some PCB congeners and reducing the toxicity of the soil environment. PMID:21596420

Slater, Heather; Gouin, Todd; Leigh, Mary Beth



Geographic Variation in Advertisement Calls in a Tree Frog Species: Gene Flow and Selection Hypotheses  

PubMed Central

Background In a species with a large distribution relative to its dispersal capacity, geographic variation in traits may be explained by gene flow, selection, or the combined effects of both. Studies of genetic diversity using neutral molecular markers show that patterns of isolation by distance (IBD) or barrier effect may be evident for geographic variation at the molecular level in amphibian species. However, selective factors such as habitat, predator, or interspecific interactions may be critical for geographic variation in sexual traits. We studied geographic variation in advertisement calls in the tree frog Hyla japonica to understand patterns of variation in these traits across Korea and provide clues about the underlying forces for variation. Methodology We recorded calls of H. japonica in three breeding seasons from 17 localities including localities in remote Jeju Island. Call characters analyzed were note repetition rate (NRR), note duration (ND), and dominant frequency (DF), along with snout-to-vent length. Results The findings of a barrier effect on DF and a longitudinal variation in NRR seemed to suggest that an open sea between the mainland and Jeju Island and mountain ranges dominated by the north-south Taebaek Mountains were related to geographic variation in call characters. Furthermore, there was a pattern of IBD in mitochondrial DNA sequences. However, no comparable pattern of IBD was found between geographic distance and call characters. We also failed to detect any effects of habitat or interspecific interaction on call characters. Conclusions Geographic variations in call characters as well as mitochondrial DNA sequences were largely stratified by geographic factors such as distance and barriers in Korean populations of H. japoinca. Although we did not detect effects of habitat or interspecific interaction, some other selective factors such as sexual selection might still be operating on call characters in conjunction with restricted gene flow.

Jang, Yikweon; Hahm, Eun Hye; Lee, Hyun-Jung; Park, Soyeon; Won, Yong-Jin; Choe, Jae C.



Comparison of temperate and tropical rainforest tree species: photosynthetic responses to growth temperature  

Microsoft Academic Search

Little is known about the differences in physiology between temperate and tropical trees. Australian rainforests extend from tropical climates in the north to temperate climates in the south over a span of 33° latitude. Therefore, they provide an opportunity to investigate differences in the physiology of temperate and tropical trees within the same vegetation type. This study investigated how the

S. Cunningham; J. Read



Using phylogeographic analyses of gene trees to test species status and processes  

Microsoft Academic Search

A gene tree is an evolutionary reconstruction of the genealogical history of the genetic vari- ation found in a sample of homologous genes or DNA regions that have experienced little or no recombination. Gene trees have the potential of straddling the interface between intra- and interspecific evolution. It is precisely at this interface that the process of speciation occurs, and




Predicting tree diameter and height from above-ground biomass for four eucalypt species  

Microsoft Academic Search

Previous work has suggested that tree stems are structured dimensionally to resist the forces to which they are subjected by the weight of the crown and the action of wind, snow and other loads on the crown. This proposition has been used to develop allometric relationships relating diameter at breast height or height of individual trees growing in even-aged monoculture

P. W. West; K. F. Wells; D. M. Cameron; S. J. Rance; C. R. A. Turnbull; C. L. Beadle



Tree-crown biomass estimation in forest species of the Ural and of Kazakhstan  

Microsoft Academic Search

Tree foliage biomass forms an essential element in forest modelling. Its measurement is costly and its relation to other measurements of standing trees have come under closer scrutiny since the introduction of the pipe model. Regressions of foliage and green shoot biomass of various levels of complexity are given, using as predictors diameter at the base of the crown (dc),

Christian W Hoffmann; Vladimir A Usoltsev



Remote sensing-based predictors improve distribution models of rare, early successional and broadleaf tree species in Utah  

USGS Publications Warehouse

1. Compared to bioclimatic variables, remote sensing predictors are rarely used for predictive species modelling. When used, the predictors represent typically habitat classifications or filters rather than gradual spectral, surface or biophysical properties. Consequently, the full potential of remotely sensed predictors for modelling the spatial distribution of species remains unexplored. Here we analysed the partial contributions of remotely sensed and climatic predictor sets to explain and predict the distribution of 19 tree species in Utah. We also tested how these partial contributions were related to characteristics such as successional types or species traits. 2. We developed two spatial predictor sets of remotely sensed and topo-climatic variables to explain the distribution of tree species. We used variation partitioning techniques applied to generalized linear models to explore the combined and partial predictive powers of the two predictor sets. Non-parametric tests were used to explore the relationships between the partial model contributions of both predictor sets and species characteristics. 3. More than 60% of the variation explained by the models represented contributions by one of the two partial predictor sets alone, with topo-climatic variables outperforming the remotely sensed predictors. However, the partial models derived from only remotely sensed predictors still provided high model accuracies, indicating a significant correlation between climate and remote sensing variables. The overall accuracy of the models was high, but small sample sizes had a strong effect on cross-validated accuracies for rare species. 4. Models of early successional and broadleaf species benefited significantly more from adding remotely sensed predictors than did late seral and needleleaf species. The core-satellite species types differed significantly with respect to overall model accuracies. Models of satellite and urban species, both with low prevalence, benefited more from use of remotely sensed predictors than did the more frequent core species. 5. Synthesis and applications. If carefully prepared, remotely sensed variables are useful additional predictors for the spatial distribution of trees. Major improvements resulted for deciduous, early successional, satellite and rare species. The ability to improve model accuracy for species having markedly different life history strategies is a crucial step for assessing effects of global change. ?? 2007 The Authors.

Zimmermann, N. E.; Edwards, Jr. , T. C.; Moisen, G. G.; Frescino, T. S.; Blackard, J. A.



Remote sensing-based predictors improve distribution models of rare, early successional and broadleaf tree species in Utah  

PubMed Central

Compared to bioclimatic variables, remote sensing predictors are rarely used for predictive species modelling. When used, the predictors represent typically habitat classifications or filters rather than gradual spectral, surface or biophysical properties. Consequently, the full potential of remotely sensed predictors for modelling the spatial distribution of species remains unexplored. Here we analysed the partial contributions of remotely sensed and climatic predictor sets to explain and predict the distribution of 19 tree species in Utah. We also tested how these partial contributions were related to characteristics such as successional types or species traits. We developed two spatial predictor sets of remotely sensed and topo-climatic variables to explain the distribution of tree species. We used variation partitioning techniques applied to generalized linear models to explore the combined and partial predictive powers of the two predictor sets. Non-parametric tests were used to explore the relationships between the partial model contributions of both predictor sets and species characteristics. More than 60% of the variation explained by the models represented contributions by one of the two partial predictor sets alone, with topo-climatic variables outperforming the remotely sensed predictors. However, the partial models derived from only remotely sensed predictors still provided high model accuracies, indicating a significant correlation between climate and remote sensing variables. The overall accuracy of the models was high, but small sample sizes had a strong effect on cross-validated accuracies for rare species. Models of early successional and broadleaf species benefited significantly more from adding remotely sensed predictors than did late seral and needleleaf species. The core-satellite species types differed significantly with respect to overall model accuracies. Models of satellite and urban species, both with low prevalence, benefited more from use of remotely sensed predictors than did the more frequent core species. Synthesis and applications. If carefully prepared, remotely sensed variables are useful additional predictors for the spatial distribution of trees. Major improvements resulted for deciduous, early successional, satellite and rare species. The ability to improve model accuracy for species having markedly different life history strategies is a crucial step for assessing effects of global change.




Gender specific patterns of carbon uptake and water use in a dominant riparian tree species exposed to a warming climate.  


Air temperatures in the arid western United States are predicted to increase over the next century. These increases will likely impact the distribution of plant species, particularly dioecious species that show a spatial segregation of the sexes across broad resource gradients. On the basis of spatial segregation patterns, we hypothesized that temperature increases will have a greater negative impact on female plants compared with co-occurring male plants of dioecious species. This hypothesis was tested by examining the whole-plant carbon and water relations of 10-year-old female (n = 18) and male (n = 13) Acer negundo Sarg. trees grown in a common garden in Salt Lake City, UT. The trees were established from cuttings collected where the growing season temperature averaged about 6.5 °C cooler than at the common garden. During May and June, stem sap flux (Js ) was similar between genders, but averaged 25% higher in males during the warmer months of July and August. Daytime canopy stomatal conductance (gs ) per unit leaf area was 12% higher in females in May : June, but was 11% higher in males in July : August. We combined measurements of sap flux-scaled transpiration with measurements of tree allometry and ?(13) C of leaf soluble sugars to estimate whole-tree carbon assimilation (Atree ) and water use efficiency (WUE) (Atree  : Etree ). Atree was similar between genders until late August when Atree was 32% higher in male trees. Atree  : Etree was on average 7% higher in females than in males during the growing season. Patterns of Js , gs , Atree and Atree  : Etree in the present study were in contrast to those previously reported for A. negundo genders under native growing season temperatures. Results suggest that the spatial segregation of the sexes could shift under global warming such that female plants lose their dominance in high-resource habitats, and males increase their dominance in relatively lower-resource habitats. PMID:23666790

Hultine, Kevin R; Burtch, Kelley G; Ehleringer, James R



Differences Between Standing and Downed Dead Tree Wood Density Reduction Factors: A Comparison Across Decay Classes and Tree Species.  

National Technical Information Service (NTIS)

Woody detritus or dead wood is an important part of forest ecosystems and has now become a routine facet of forest monitoring and inventory. Biomass and carbon estimates of dead wood depend on knowledge of species- and decay class- specifi c density or de...

B. Fasth C. W. Woodall J. Sexton M. Yatkov M. E. Harmon



High population differentiation and unusual haplotype structure in a shade-intolerant pioneer tree species, Zanthoxylum ailanthoides (Rutaceae) revealed by analysis of DNA polymorphism at four nuclear loci  

Microsoft Academic Search

Differences in demographic history, life-history traits, and breeding systems affect nucleotide variation patterns. It is expected that shade-intolerant pioneer tree species have different patterns of genetic polymorphism and population structure than climax species. We studied patterns of nucleotide polymorphism at four putative starch pathway loci (agpSA, agpSB, agpL, and GBSSI) in Zanthoxylum ailanthoides, a shade-intolerant pioneer tree species that occupies





Microsoft Academic Search

Epiphytic lichen and bryophyte species composition, richness and diversity were surveyed on basal trunks of six common old-growth forest tree species,Picea abies,Pinus sylvestris,Betula pendula,Alnus incana,Salix capreaandPopulus tremula, in two old-growth forest areas, one in southern and one in middle boreal Finland. The average species numbers per tree ranged from 18 (Picea) to 27 (Salix) in the southern and from 20




Individual-tree diameter growth and mortality models for bottomland mixed-species hardwood stands in the lower Mississippi alluvial valley  

Microsoft Academic Search

Individual-tree diameter growth and mortality models were developed for the bottomland mixed-species hardwood stands in the Lower Mississippi Alluvial Valley (LMAV). Data came from 5-year remeasurements of continuous forest inventory plots. Six species groups were created according to diameter structure, tree growth, mortality, recruitment and light demand of species. A 5-year basal area increment model and logistic mortality model were

Dehai Zhao; Bruce Borders; Machelle Wilson



Effects of species-specific leaf characteristics and reduced water availability on fine particle capture efficiency of trees.  


Trees can improve air quality by capturing particles in their foliage. We determined the particle capture efficiencies of coniferous Pinus sylvestris and three broadleaved species: Betula pendula, Betula pubescens and Tilia vulgaris in a wind tunnel using NaCl particles. The importance of leaf surface structure, physiology and moderate soil drought on the particle capture efficiencies of the trees were determined. The results confirm earlier findings of more efficient particle capture by conifers compared to broadleaved plants. The particle capture efficiency of P. sylvestris (0.21%) was significantly higher than those of B. pubescens, T. vulgaris and B. pendula (0.083%, 0.047%, 0.043%, respectively). The small leaf size of P. sylvestris was the major characteristic that increased particle capture. Among the broadleaved species, low leaf wettability, low stomatal density and leaf hairiness increased particle capture. Moderate soil drought tended to increase particle capture efficiency of P. sylvestris. PMID:23735814

Räsänen, Janne V; Holopainen, Toini; Joutsensaari, Jorma; Ndam, Collins; Pasanen, Pertti; Rinnan, Asmund; Kivimäenpää, Minna



First record of Bursaphelenchus rainulfi on pine trees from eastern China and its phylogenetic relationship with intro-genus species*  

PubMed Central

Bursaphelenchus rainulfi isolated from dead pine trees in Zhejiang, China, is described and illustrated. It also provided some molecular characters of the Chinese population, including the PCR-RFLP and sequences of ITS region and D2-D3 expansion region of the large subunit (LSU) rRNA gene. Both the morphological characters and ITS-RFLP patterns match with the original description. The phylogenetic trees based on the 13 sequences of D2-D3 expansion region of the LSU rRNA gene and ITS region of Bursaphelenchus species were constructed, respectively, with the results showing the similar clades. The phylogenetic relationship based on the molecular data is similar to that with morphological characters. This is the first report of the species on pine wood in eastern China.

Jiang, Li-qin; Li, Xu-qing; Zheng, Jing-wu



Small multipurpose stored data acquisition system.  

National Technical Information Service (NTIS)

Sandia National Laboratories Telemetry Department has designed and is fielding a small, inexpensive multipurpose stored data acquisition system in tests ranging from 6000 meters below the ocean surface in seafloor penetrators to 40,000 meters above sea le...

G. C. Hauser D. E. Ryerson



Facilitation and Inhibition of Seedlings of an Invasive Tree ( Acer platanoides ) by Different Tree Species in a Mountain Ecosystem  

Microsoft Academic Search

Facilitation is known to be an important process structuring natural plant communities. However, much less is known about\\u000a its role in facilitating the invasion of ecosystems by non-native plant species. In this study we evaluated the effects of\\u000a invasive (Acer platanoides) and native (Pseudotsuga menziesii) forest types on the performance of A. platanoides seedlings, and related these effects to structural

K. O. Reinhart; Fernando T. Maestre; Ragan M. Callaway



Litter dynamics and soil properties under different tree species in a semi-arid region of Rajasthan, India  

Microsoft Academic Search

Litterfall and decomposition are the two main processes accounting for soil enrichment in agroforestry. The extent of enrichment\\u000a in soil properties depends on the tree species, management practices and the quantity and quality of litter. A field investigation\\u000a was carried out to study litterfall production, decay rates, release of nutrients and consequent changes in soil physicochemical\\u000a properties under crowns of

R. S. Yadav; B. L. Yadav; B. R. Chhipa



Litterfall, litter decomposition and the use of mulch of four indigenous tree species in the Atlantic lowlands of Costa Rica  

Microsoft Academic Search

Litterfall, forest-floor litter biomass and nutrients, short-term litter decomposition and the effects of leaf mulches on initial growth of maize were studied for four indigenous tree species with agroforestry potential:Stryphnodendron microstachyum Poepp. et Endl.(S. excelsum), Vochysia ferruginea Mart,Vochysia guatemalensis Donn. Sm. (V. hondurensis) andHyeronima alchorneoides (O), growing in a young experimental plantation in the Atlantic humid lowlands of Costa Rica.

F. Montagnini; K. Ramstad; F. Sancho



Genetic diversity of Dalbergia monticola (Fabaceae) an endangered tree species in the fragmented oriental forest of Madagascar  

Microsoft Academic Search

There is an urgent need to maintain and restore a broad genetic base for the management of Dalbergia monticola, a very economically important but endangered tree species in Madagascar. Random amplified polymorphism DNAs (RAPDs) and\\u000a chloroplast micro-satellite markers were used to quantify the genetic variation and to analyse the geographic distribution\\u000a of diversity. Ten locations covering most of the natural

Olivarimbola Andrianoelina; Hery Rakotondraoelina; Lolona Ramamonjisoa; Jean Maley; Pascal Danthu; Jean-Marc Bouvet


Genetic Diversity of Dalbergia monticola (Fabaceae) an Endangered Tree Species in the Fragmented Oriental Forest of Madagascar  

Microsoft Academic Search

There is an urgent need to maintain and restore a broad genetic base for the management of Dalbergia monticola, a very economically important but endangered tree species in Madagascar. Random amplified polymorphism DNAs (RAPDs) and\\u000a chloroplast microsatellite markers were used to quantify the genetic variation and to analyse the geographic distribution\\u000a of diversity. Ten locations covering most of the natural

Olivarimbola Andrianoelina; Hery Rakotondraoelina; Lolona Ramamonjisoa; Jean Maley; Pascal Danthu; Jean-Marc Bouvet



Inferring Species Networks from Gene Trees in High-Polyploid North American and Hawaiian Violets (Viola, Violaceae)  

PubMed Central

The phylogenies of allopolyploids take the shape of networks and cannot be adequately represented as bifurcating trees. Especially for high polyploids (i.e., organisms with more than six sets of nuclear chromosomes), the signatures of gene homoeolog loss, deep coalescence, and polyploidy may become confounded, with the result that gene trees may be congruent with more than one species network. Herein, we obtained the most parsimonious species network by objective comparison of competing scenarios involving polyploidization and homoeolog loss in a high-polyploid lineage of violets (Viola, Violaceae) mostly or entirely restricted to North America, Central America, or Hawaii. We amplified homoeologs of the low-copy nuclear gene, glucose-6-phosphate isomerase (GPI), by single-molecule polymerase chain reaction (PCR) and the chloroplast trnL-F region by conventional PCR for 51 species and subspecies. Topological incongruence among GPI homoeolog subclades, owing to deep coalescence and two instances of putative loss (or lack of detection) of homoeologs, were reconciled by applying the maximum tree topology for each subclade. The most parsimonious species network and the fossil-based calibration of the homoeolog tree favored monophyly of the high polyploids, which has resulted from allodecaploidization 9–14 Ma, involving sympatric ancestors from the extant Viola sections Chamaemelanium (diploid), Plagiostigma (paleotetraploid), and Viola (paleotetraploid). Although two of the high-polyploid lineages (Boreali-Americanae, Pedatae) remained decaploid, recurrent polyploidization with tetraploids of section Plagiostigma within the last 5 Ma has resulted in two 14-ploid lineages (Mexicanae, Nosphinium) and one 18-ploid lineage (Langsdorffianae). This implies a more complex phylogenetic and biogeographic origin of the Hawaiian violets (Nosphinium) than that previously inferred from rDNA data and illustrates the necessity of considering polyploidy in phylogenetic and biogeographic reconstruction.

Marcussen, Thomas; Jakobsen, Kjetill S.; Danihelka, Jiri; Ballard, Harvey E.; Blaxland, Kim; Brysting, Anne K.; Oxelman, Bengt



Multi-locus species tree for the Amazonian peacock basses (Cichlidae: Cichla): Emergent phylogenetic signal despite limited nuclear variation.  


The inference of phylogenies of closely related species is obstructed by phenomena such as porous species boundaries and deep coalescence, and is often exacerbated by low levels of nucleotide variation among most loci surveyed in phylogenetic studies. We investigated the utility of twenty-one nuclear loci that had a range of 5-40 (median of 14) variable sites per locus to estimate the phylogeny of the genus Cichla, a group of 15 Neotropical cichlid fishes that began to diverge in the early to mid Miocene. We found that under a concatenated approach, the least variable loci, while contributing less to the overall phylogenetic signal (posterior node support), nevertheless provided information that increased support for the final tree. Moreover, this was not a result of misdirection by mutational noise, as the inference from all data was far superior to those from reduced datasets (those with more variable loci) in terms of the relative precision of posterior tree space. Phylogenetic methods that allowed each locus to have a separate genealogy, including Bayesian concordance analysis and a multispecies coalescent model, provided phylogenies that were also compatible with the concatenated tree in terms of the eight recently delimited species of Cichla, albeit with somewhat diminished support for some branches. In contrast, described species that still regularly exchange genes showed unstable relationships among analyses: not a surprising result from analyses that assume that gene tree heterogeneity results from incomplete lineage sorting and not gene flow. Importantly, we also observed that the confidence intervals for node ages in the coalescent analyses were quite wide, and likely susceptible to influence of the prior on node density (e.g. birth-death). PMID:23939135

Willis, Stuart C; Farias, Izeni P; Ortí, Guillermo



Do coarse resolution U.S. presettlement land survey records adequately represent the spatial pattern of individual tree species?  

Microsoft Academic Search

Presettlement land survey records (PLSRs) are a valuable and unique source of information for the reconstruction of presettlement\\u000a forest patterns. The purpose of this study was to determine whether coarsely resolved PLSRs are adequate to characterize the\\u000a spatial patterns of individual tree species over large areas. The General Land Office Survey records of the PLSRs of Minnesota\\u000a were used and

Yi-Chen Wang; Chris P. S. Larsen



Object-Oriented Classification of LIDAR-Fused Hyperspectral Imagery for Tree Species Identification in an Urban Environment  

Microsoft Academic Search

The objective of the current study was to develop a methodology for the identification of tree species in an urban environment by using Quickbird multispectral data, AISA hyperspectral data, AISA Eagle hyperspectral data and Leica ALS50 LiDAR data. For this research, object-oriented classification was performed using eCognition Professional. The classifications were performed on each of the images available with and

Ramanathan Sugumaran; Matthew Voss



Control of Nitrogen Loss from Forested Watersheds by Soil Carbon:Nitrogen Ratio andTree Species Composition  

Microsoft Academic Search

Leaching losses of nitrate from forests can have potentially serious consequences for soils and receiving waters. In this\\u000a study, based on extensive sampling of forested watersheds in the Catskill Mountains of New York State, we examine the relationships\\u000a among stream chemistry, the properties of the forest floor, and the tree species composition of watersheds. We report the\\u000a first evidence from

Gary M. Lovett; Kathleen C. Weathers; Mary A. Arthur



Thysanoptera (thrips) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, and species on vines and ground cover plants.  


Seven citrus orchards on reduced to no pesticide spray programs were sampled for Thysanoptera in central and south central Florida. Inner and outer canopy leaves, fruits, twigs, trunk scrapings, vines and ground cover plants were sampled monthly between January 1995 and January 1996. Thirty-six species of thrips were identified from 2,979 specimens collected from within citrus tree canopies and 18,266 specimens from vines and ground cover plants within the seven citrus orchards. The thrips species included seven predators [Aleurodothrips fasciapennis (Franklin), Karnyothrips flavipes (Jones), K. melaleucus (Bagnall), Leptothrips cassiae (Watson), L. macroocellatus (Watson), L. pini (Watson), and Scolothrips sexmaculatus (Pergande)] 21 plant feeding species [Anaphothrips n. sp., Arorathrips mexicanus (Crawford), Aurantothrips orchidaceous (Bagnall), Baileyothrips limbatus (Hood), Chaetanaphothrips orchidii (Moulton), Danothrips trifasciatus (Sakimura), Echinothrips americanus (Morgan), Frankliniella bispinosa (Morgan), F. cephalica (Crawford), F. fusca (Hinds), F. gossypiana (Hood), Frankliniella sp. (runneri group), Haplothrips gowdeyi (Franklin), Heliothrips haemorrhoidalis (Bouché), Leucothrips piercei (Morgan), Microcephalothrips abdominalis (Crawford), Neohydatothrips floridanus (Watson), N. portoricensis (Morgan), Pseudothrips inequalis (Beach), Scirtothrips sp., and Thrips hawaiiensis (Morgan)]; and eight fungivorous feeding species [Adraneothrips decorus (Hood), Hoplandrothrips pergandei (Hinds), Idolothripinae sp., Merothrips floridensis (Watson), M. morgani (Hood), Neurothrips magnafemoralis (Hinds), Stephanothrips occidentalis Hood and Williams, and Symphyothrips sp.]. Only F. bispinosa, C. orchidii, D. trifasciatus, and H. haemorrhoidalis have been considered economic pests on Florida citrus. Scirtothrips sp. and T. hawaiiensis were recovered in low numbers within Florida citrus orchards. Both are potential pest species to citrus and possibly other crops in Florida. The five most abundant thrips species collected within citrus tree canopies were: A. fasciapennis, F. bispinosa, C. orchidii, K. flavipes, and D. trifasciatus. In comparison, the following five thrips species were most abundant on vines or ground cover plants: F. bispinosa, H. gowdeyi, F. cephalica, M. abdominalis, and F. gossypiana. Fifty-eight species of vines or ground cover plants in 26 families were infested with one or more of 27 species of thrips. PMID:20233100

Childers, Carl C; Nakahara, Sueo



[Effects of relative abundance of Quercus mongolica acorns on five tree species seed dispersal in Xiaoxing' an Mountains, Northeast China].  


An investigation was conducted in a forest farm in the Xiaoxing' an Mountains in autumn, 2009 and 2010 to study the effects of Quercus mongolica acorn quantity and rodent density on the seed dispersal of five tree species (Juglans mandshurica, Pinus koraiensis, Corylus mandshurica, Corylus heterophylla, and Q. mongolica). In the farm, there was an annual change in rodent density. The total capture rate of small rodents in 2009 (31.0%) was significantly higher than that in 2010 (16.7%). The acorn quantity and relative seed abundance (per capita rodent) of Quercus mongolica in 2009 (6.2 +/- 2.1 acorns x m(-2) and 20.0, respectively) were significantly lower than those in 2010 (26.7 +/- 10.2 acorns x m(-2) and 160.0, respectively). In 2009, all the seeds of the five tree species except J. mandshurica were dispersed or eaten in situ, among which, the acorns of Q. mongolica were scatter-hoarded most, and their average dispersal distance was the furthest. In 2010, the seeds of J. mandshurica were scatter-hoarded most, and their average dispersal distance was the furthest. The relative seed abundance of Q. mongolica could be the key factor determining the seed dispersal of the other tree species in the study area. PMID:24066536

Yu, Fei; Shi, Xiao-Xiao; Yi, Xian-Feng; Wang, De-Xiang




Microsoft Academic Search

Many studies have shown that initial tree diameter is closely correlated with subsequent tree growth. But initial tree diameter is actually a confounded variable, incorporating both competitive position (crown class) and age. A study in hardwood stands in Pennsylvania has shown that the two latter variables were more reliable predictors of tree growth than initial diameter. These two variables lack

David A. Marquis


Effects of calcium on seed germination, seedling growth and photosynthesis of six forest tree species under simulated acid rain.  


We selected six tree species, Pinus massoniana Lamb., Cryptomeria fortunei Hooibr. ex Otto et Dietr., Cunninghamia lanceolata (Lamb.) Hook., Liquidambar formosana Hance, Pinus armandii Franch. and Castanopsis chinensis Hance, which are widely distributed as dominant species in the forest of southern China where acid deposition is becoming more and more serious in recent years. We investigated the effects and potential interactions between simulated acid rain (SiAR) and three calcium (Ca) levels on seed germination, radicle length, seedling growth, chlorophyll content, photosynthesis and Ca content in leaves of these six species. We found that the six species showed different responses to SiAR and different Ca levels. Pinus armandii and C. chinensis were very tolerant to SiAR, whereas the others were more sensitive. The results of significant SiAR?×?Ca interactions on different physiological parameters of the six species demonstrate that additional Ca had a dramatic rescue effect on the seed germination and seedling growth for the sensitive species under SiAR. Altogether, we conclude that the negative effects of SiAR on seed germination, seedling growth and photosynthesis of the four sensitive species could be ameliorated by Ca addition. In contrast, the physiological processes of the two tolerant species were much less affected by both SiAR and Ca treatments. This conclusion implies that the degree of forest decline caused by long-term acid deposition may be attributed not only to the sensitivity of tree species to acid deposition, but also to the Ca level in the soil. PMID:21470980

Liu, Ting-Wu; Wu, Fei-Hua; Wang, Wen-Hua; Chen, Juan; Li, Zhen-Ji; Dong, Xue-Jun; Patton, Janet; Pei, Zhen-Ming; Zheng, Hai-Lei



Tree Species for Planting in Forest, Rural, and Urban Areas of Puerto Rico.  

National Technical Information Service (NTIS)

Responding to near total deforestation in Puerto Rico, in the 1920's the U.S. Department of Agriculture, Forest Service, began to produce tree seedlings, reforest degraded lands, establish planting trials, and conduct silvicultural research.

J. K. Francis



Greater Soil Carbon Sequestration under Nitrogen-fixing Trees Compared with Eucalyptus Species  

Microsoft Academic Search

Forests with nitrogen-fixing trees (N–fixers) typically accumulate more carbon (C) in soils than similar forests without N–fixing\\u000a trees. This difference may develop from fundamentally different processes, with either greater accumulation of recently fixed\\u000a C or reduced decomposition of older soil C. We compared the soil C pools under N–fixers with Eucalyptus (non–N–fixers) at four tropical sites: two sites on Andisol

Sigrid C. Resh; Dan Binkley; John A. Parrotta



Using Haplotype Trees for Phylogeographic and Species Inference in Fish Populations  

Microsoft Academic Search

Genetic variation is now routinely screened at the DNA sequence level in many studies. If the DNA region being screened has\\u000a not experienced excessive amounts of recombination, it is often possible to reconstruct the evolutionary history of the genetic\\u000a variation in the form of a haplotype tree. This tree estimates the evolutionary pathway that interconnects all the different\\u000a haplotypes (sequence

Alan R. Templeton



A rapid and efficient method for the isolation of mitochondrial DNA from angiosperm tree species. Application to the restriction fragment length polymorphism distinction between European and American ashes  

Microsoft Academic Search

A simplified method for the isolation of mitochondrial DNA (mtDNA) from several angiosperm tree species is described. The procedure does not require gradient ultracen- trifugation or organic solvent extractions and can be performed in a single day. mtDNA was isolated from flower buds collected from adult trees just after the first pollen mitosis and purified by gravity flow through disposable

M. E. Morand; F. Vedel; C. Raquin; N. Frascaria-Lacoste



Seedling establishment of five evergreen tree species in relation to topography, sika deer (Cervus nippon yakushimae) and soil surface environments.  


We investigated the seedling survival of five evergreen tree species over 3 years inside and outside deer-exclusion fences in a warm temperate evergreen broad-leaved forest on Yakushima Island, Japan. Seedling survival was examined in relation to topography, herbivory by sika deer, and the soil surface environment (i.e., soil surface wetness, light conditions, slope inclination, and soil disturbance). The study species included Myrsine seguinii Lév., Syzygium buxifolium Hook. et Arn. (Group A: species distributed on the upper slope of the study site), Litsea accuminata (Bl.) Kurata, Schefflera octophylla (Lour.) Harms (Group B: species distributed on the lower slope), and Cleyera japonica Thunb. p.p. emend. Sieb. et Zucc. (Group C: species distributed on both slopes). The soil surface environment on the upper slope was drier, lighter, and more easily disturbed than the lower slope. Generalized linear model analyses indicated that seedling survival in fenced and unfenced quadrats was greater on the upper slope than on the lower slope for Group A and B species but not for Group C species. A micro-spatial scale analysis revealed that seedling survival was correlated with soil wetness, ground light conditions, and soil disturbance but not slope inclination. These results indicate that seedling survival was correlated with topography, sika deer herbivory, and the micro-spatial scale environment. Topography-related differences in seedling survival appear to adequately reflect the observed adult plant distributions for Group A and C species but not for Group B species. PMID:18704623

Tsujino, Riyou; Yumoto, Takakazu



Tree Species Identity Affects Soil CO2 and N2O Fluxes in Primary Forest and Plantation Sites in Amazonia  

NASA Astrophysics Data System (ADS)

Tropical soils are a large and highly variable source of natural CO2 and N2O flux to the atmosphere. Soil texture and moisture have limited ability to explain this variability, probably because in moist clayey soils, denitrification can be a significant contributor, but this process is carbon limited. Vegetation characteristics, including species composition, should therefore influence CO2 and N{_2}O fluxes through their effect on quantity and quality of carbon inputs. To test whether tree species composition influence soil gas fluxes we studied two sites (km 67 and Belterra plantation) south of Santarem, Brazil. Soils at both sites are clay-rich and not N-limited. We measured CO2 and N2O fluxes and surface soil bulk density, moisture, and temperature within 2 m of large (DBH >35 cm), randomly selected trees from 12 species within survey transects (total area ~ 50ha) at the km 67 primary forest site and in monoculture plots on a plantation on similar soil in Belterra. Irrespective of soil factors, N2O fluxes close to Piquia were elevated relative to Quarubarana and Quaruba verdadeira (QV) within the forest and relative to Jarana and Angelim da mata on the plantation. Here CO2 fluxes were high under Piquia, QV and Macaranduba and low under Jarana and Castanha da Para. We found no statistical differences between the mean CO2 fluxes close to the selected tree species within the primary forest. Our analyses suggest that soil gas fluxes can be modeled by species composition, even in complex forests.

van Haren, J.; Oliveira, R.; Keller, M.; Saleska, S.



The Astrophysical Multipurpose Software Environment  

NASA Astrophysics Data System (ADS)

We present the open source Astrophysical Multi-purpose Software Environment (AMUSE), a component library for performing astrophysical simulations involving different physical domains and scales. It couples existing codes within a Python framework based on a communication layer using MPI. The interfaces are standardized for each domain and their implementation based on MPI guarantees that the whole framework is well-suited for distributed computation. It includes facilities for unit handling and data storage. Currently it includes codes for gravitational dynamics, stellar evolution, hydrodynamics and radiative transfer. Within each domain the interfaces to the codes are as similar as possible. We describe the design and implementation of AMUSE, as well as the main components and community codes currently supported and we discuss the code interactions facilitated by the framework. Additionally, we demonstrate how AMUSE can be used to resolve complex astrophysical problems by presenting example applications. The current version of the code is available at the CDS via anonymous ftp to ( or via

Pelupessy, F. I.; van Elteren, A.; de Vries, N.; McMillan, S. L. W.; Drost, N.; Portegies Zwart, S. F.



[Multipurpose treatment of vaginal infections].  


Untreated bacterial vaginosis is related with many complications for non-pregnant women in reproductive age, most common from them are vaginal discharge and postoperative infections. The aim of our investigation was to compare the effectiveness of two therapeutic regimes which consist in Macmiror/Macmiror Complex alone and in combination with Feminella Vagi C for treatment of bacterial vaginosis (BV) and/or mycotic infection. 117 non-pregnant women with symptoms of vaginal infection were prospectively enrolled into two groups according their treatment. First group consist 66 women treated with Macmiror tablets and vaginal capsules followed with local application of Feminella Vagi C, the second group consist 54 women treated with Macmiror tablets and vaginal capsules only. The impact of treatment on clinical symptoms was observed at the end of medication and 20 days after it. Microbiological testing was repeated 20 days after treatment. Over than 80% (78.6 divided by 86.7%) of the cases with vaginal infection (BV and mycotic one) were successfully treated with Macmiror/Macmiror Complex. Supplement treatment with Feminella Vagi C lead to higher percentage of clinically recovery (86.7% vs 84.6%), better microbiological cleaning (86.7% vs 82.1%) and longer effect of treatment. Used medication showed higher efficacy against BV than to fungal infection. According obtained results we may conclude that bacterial vaginosis was better treated with multipurpose treatment (Nifuratel, Nistatin and vit. C) than with Macmiror alone. PMID:23234030

Nikolov, A; Masseva, A; Shopova, E; Georgiev, S



A review of the jumping tree bugs (Hemiptera: Heteroptera: Miridae: Isometopinae) of Argentina and nearby areas of Brazil and Paraguay, with descriptions of nine new species  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nine new species of jumping tree bugs, or Isometopinae, from Argentina, Paraguay, and southern Brazil are described. The genus Aristotelesia is revised and the two new species A. fuscata (Brazil) and A. medialis (Argentina) are described, and the Argentine and Paraguayan species of Myiomma are revie...


Light-dependent changes in the relationship between seed mass and seedling traits: a meta-analysis for rain forest tree species  

Microsoft Academic Search

Seed mass is considered to be an important attribute for the establishment success of plant species being linked with their seed production, establishment, and survival. This meta-analysis shows that seed mass is also closely correlated to growth-related species attributes of the established phase of rain forest tree species, and that the strength of this relationship varies with light conditions. Seed

Lourens Poorter; Simmoné A. Rose



Fog reduces transpiration in tree species of the Canarian relict heath-laurel cloud forest (Garajonay National Park, Spain).  


The ecophysiologic role of fog in the evergreen heath-laurel 'laurisilva' cloud forests of the Canary Islands has not been unequivocally demonstrated, although it is generally assumed that fog water is important for the survival and the distribution of this relict paleoecosystem of the North Atlantic Macaronesian archipelagos. To determine the role of fog in this ecosystem, we combined direct transpiration measurements of heath-laurel tree species, obtained with Granier's heat dissipation probes, with micrometeorological and artificial fog collection measurements carried out in a 43.7-ha watershed located in the Garajonay National Park (La Gomera, Canary Islands, Spain) over a 10-month period. Median ambient temperature spanned from 7 to 15 degrees C under foggy conditions whereas higher values, ranging from 9 to 21 degrees C, were registered during fog-free periods. Additionally, during the periods when fog water was collected, global solar radiation values were linearly related (r2=0.831) to those under fog-free conditions, such that there was a 75+/-1% reduction in median radiation in response to fog. Fog events greatly reduced median diurnal tree transpiration, with rates about 30 times lower than that during fog-free conditions and approximating the nighttime rates in both species studied (the needle-like leaf Erica arborea L. and the broadleaf Myrica faya Ait.). This large decrease in transpiration in response to fog was independent of the time of the day, tree size and species and micrometeorological status, both when expressed on a median basis and in cumulative terms for the entire 10-month measuring period. We conclude that, in contrast to the turbulent deposition of fog water droplets on the heath-laurel species, which may be regarded as a localized hydrological phenomenon that is important for high-altitude wind-exposed E. arborea trees, the cooler, wetter and shaded microenvironment provided by the cloud immersion belt represents a large-scale effect that is crucial for reducing the transpirational water loss of trees that have profligate water use, such as those of the 'laurisilva'. PMID:19203969

Ritter, Axel; Regalado, Carlos M; Aschan, Guido



High variation in foliage and leaf litter chemistry among 45 tree species of a neotropical rainforest community.  


Distinct ecosystem level carbon : nitrogen : phosphorus (C : N : P) stoichiometries in forest foliage have been suggested to reflect ecosystem-scale selection for physiological strategies in plant nutrient use. Here, this hypothesis was explored in a nutrient-poor lowland rainforest in French Guiana. Variation in C, N and P concentrations was evaluated in leaf litter and foliage from neighbour trees of 45 different species, and the litter concentrations of major C fractions were also measured. Litter C ranged from 45.3 to 52.4%, litter N varied threefold (0.68-2.01%), and litter P varied seven-fold (0.009-0.062%) among species. Compared with foliage, mean litter N and P concentrations decreased by 30% and 65%, respectively. Accordingly, the range in mass-based N : P shifted from 14 to 55 in foliage to 26 to 105 in litter. Resorption proficiencies indicated maximum P withdrawal in most species, but with a substantial increase in variation in litter P compared with foliage. These data suggest that constrained ecosystem-level C : N : P ratios do not preclude the evolution of highly diversified strategies of nutrient use and conservation among tropical rainforest tree species. The resulting large variation in litter quality will influence stoichiometric constraints within the decomposer food web, with potentially far-ranging consequences on nutrient dynamics and plant-soil feedbacks. PMID:18422903

Hättenschwiler, Stephan; Aeschlimann, Beat; Coûteaux, Marie-Madeleine; Roy, Jacques; Bonal, Damien



Mapping species density of trees, shrubs and vines in a tropical forest, using field measurements, satellite multiespectral imagery and spatial interpolation  

Microsoft Academic Search

We estimated the number of species in a tropical forest landscape in Quintana Roo, Mexico, based on the relationship between\\u000a reflectance values of satellite imagery and field measurements of plant species density (mean number of species per plot).\\u000a Total species density as well as that of tree, shrub and vine species were identified from 141 sampling quadrats (16543 individuals\\u000a sampled).

J. Luis Hernández-Stefanoni; Juan Manuel Dupuy



Long-term presence of tree species but not chemical diversity affect litter mixture effects on decomposition in a neotropical rainforest  

Microsoft Academic Search

Plant litter diversity effects on decomposition rates are frequently reported, but with a strong bias towards temperate ecosystems.\\u000a Altered decomposition and nutrient recycling with changing litter diversity may be particularly important in tree species-rich\\u000a tropical rainforests on nutrient-poor soils. Using 28 different mixtures of leaf litter from 16 Amazonian rainforest tree\\u000a species, we tested the hypothesis that litter mixture effects

Sandra Barantal; Jacques Roy; Nathalie Fromin; Heidy Schimann; Stephan Hättenschwiler


Environmental heterogeneity and disturbance by humans control much of the tree species diversity of Atlantic montane forest fragments in SE Brazil  

Microsoft Academic Search

The effects of human impact and environmental heterogeneity on the tree species diversity were assessed in 20 fragments of\\u000a tropical montane seasonal forest in southeastern Brazil. Previous surveys of the tree community, soils and topography of the\\u000a fragments provided the bulk of the data. The diversity parameters used were the means of species richness, Shannon diversity\\u000a (H?), and Pielou evenness

José Aldo A. Pereira; Ary T. Oliveira-Filho; José P. Lemos-Filho



Environmental heterogeneity and disturbance by humans control much of the tree species diversity of Atlantic montane forest fragments in SE Brazil  

Microsoft Academic Search

The effects of human impact and environmental heterogeneity on the tree species diversity were assessed in 20 fragments of\\u000a tropical montane seasonal forest in southeastern Brazil. Previous surveys of the tree community, soils and topography of the\\u000a fragments provided the bulk of the data. The diversity parameters used were the means of species richness, Shannon diversity\\u000a (H?), and Pielou evenness

José Aldo A. Pereira; Ary T. Oliveira-Filho; José P. Lemos-Filho


Effects of aluminium and mineral nutrition on growth and chemical composition of hydroponically grown seedlings of five different forest tree species  

Microsoft Academic Search

Forest die-back and impaired tree vitality have frequently been ascribed to Al-toxicity and Al-induced nutritional disorders\\u000a due to increased acidification of forest soils. Therefore, in this experiment effects of Al were studied on growth and nutrient\\u000a uptake with seedlings of five different forest tree species. During growth in culture solutions with and without Al all five\\u000a species proved to be

Willem G. Keltjens; Elisabeth van Loenen



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

Microsoft Academic Search

This study is a part of a research programme on selection and improvement of fast growing tree species suitable for wood fuel production on sodic wastelands (pH 8.6–10.5). Field trials of nine legumes (Acacia auriculiformis, A. nilotica, Albizia lebbeck, A. procera, Dalbergia sissoo, Leucaena leucocephala, Pongamia pinnata, Prosopis juliflora, Pithecellobium dulce) and three other tree species (Azadirachta indica, Eucalyptus tereticornis

V. L Goel; H. M Behl



Water Chemistry and Temporal Variation of Nutrients in Stemflow of Three Dominant Tree Species in the Subtropics of the Fu-Shan Forest  

Microsoft Academic Search

The chemistry of stemflow for the forests at Fu-shan site has not been studied. The objective of this study was to compare stemflow of three dominant tree species in a subtropical rain forest of northeastern (NE) Taiwan. The three dominant tree species were yellow basket-willow (Engelhardtia roxburghiana), Morris persimmon (Diospyros morrisiana) and Chinese cryptocarya (Cryptocarya chinensis). Stemflow from yellow basket-willow

Chiung-Pin Liu; Hen-Biau King; Ming-Kuang Wang; Yue-Joe Hsia; Jeen-Lian Hwong



Reactive schedule modification in multipurpose batch chemical plants  

SciTech Connect

A new scheme is described for reactive schedule modification in the face of unexpected deviations in processing times and unit availabilities of a multipurpose batch plant (MBP). Schedule modification is done using at least impact heuristic beam search which proceeds in two levels: creation of a decision tree which makes use of possible reroutings of the product that is causing a conflict, and heuristic pruning of the search space to contain the combinatorial complexity. The heuristic chooses a path among all possible reroutings for a product such that the impact of each decision on the rest of the schedule is kept as small as possible. This approach has been implemented and tested on a number of simulated deviations in a MBP case study with three products. The proposed least impact heuristic was found to perform better than the earliest finishing unit heuristic in all the cases considered.

Kanakamedala, K.B.; Reklaitis, G.V.; Venkatasubramanian, V. (Purdue Univ., West Lafayette, IN (United States). School of Chemical Engineering)



Evaluation of the yield of Lentinus squarrosulus (Mont) Singer on selected economic tree species.  


Sawdust from seven economic trees (Mansonia altissima, Piptadeniastrum africanum, Nesogordonia papaverifera, Combretodendron macrocarpum, Terminalia sp., Khaya ivorensis and Brachystegia nigerica were used to cultivate Lentinus squarrosulus (Mont) Singer. The highest mycelial density was observed in the sawdust of Mansonia altissimia and lowest in Piptadeniastrum africanum. Time of premodial emergence, fresh weight of mushroom and number of flushes varied from one sawdust to the other. The best sawdust for the growth of this mushroom among the sawdust of the economic trees was that of Combretodendron macrocarpum. PMID:19086587

Ayodele, S M; Akpaja, E O; Anyiador, F



Growth analysis of nine multipurpose woody legumes native from southern Mexico  

Microsoft Academic Search

The growth of nine multipurpose woody legumes was evaluated in nursery conditions. These species, belonging to the genera Acacia, Leucaena, Lysiloma, Prosopis and Pithecellobium, inhabit both primary and secondary tropical deciduous and thorn forests. The total length of the experiments was 165 days. At a variable frequency, the following four variables were measured: (1) relative growth rate (RGR), (2) root\\/shoot

Virginia Cervantes; Vicente Arriaga; Jorge Meave; Julia Carabias



The genus Drosophila as a model for testing tree- and character-based methods of species identification using DNA barcoding.  


DNA barcoding has recently been proposed as a promising tool for the (1) rapid assignment of unknown samples to described species by non-expert workers and (2) a potential method of new species discovery based on degree of DNA sequence divergence. Two broad methods have been used, one based on degree of DNA sequence variation, within and between species and another requiring the recovery of species as discrete clades (monophyly) on a phylogenetic tree. An alternative method relies on the identification of a set of specific diagnostic nucleotides for a given species (characters). The genus Drosophila has long served as a model system in genetics, development, ecology and evolutionary biology. As a result of this work, species boundaries within this genus are quite well delimited, with most taxa being defined by morphological characters and also conforming to a biological species concept (e.g., partial or complete reproductive isolation has used to erect and define species). In addition, some of the species in this group have also been subjected to phylogenetic analysis, yielding cases where taxa both conform and conflict with a phylogenetic species concept. Here, we analyzed 1058 COI sequences belonging to 68 species belonging to Drosophila and its allied genus Zaprionus and with more than a single representative to assess the performance of the three DNA barcoding methods. 26% of the species could not be defined using distance methods, i.e. had a barcoding gap of ? 0, and 23% were not monophyletic. We focused then on four groups of closely-related species whose taxonomy is well-established on non-molecular basis (e.g., morphology, geography, reproductive isolation) and to which most of the problematic species belonged. We showed that characters performed better than other approaches in the case of paraphyletic species, but all methods failed in the case of polyphyletic species. For these polyphyletic species, other sources of evidence (e.g., morphology, geography, reproductive isolation) are more relevant than COI sequences, highlighting the limitation of DNA barcoding and the needs for integrative taxonomy approaches. In conclusion, DNA barcoding of Drosophila shows no reason to alter the 250 years old tradition of character-based taxonomy, and many reasons to shy away from the alternatives. PMID:20800099

Yassin, Amir; Markow, Therese A; Narechania, Apurva; O'Grady, Patrick M; DeSalle, Rob



Host preferences and differential contributions of deciduous tree species shape mycorrhizal species richness in a mixed Central European forest  

Microsoft Academic Search

Summary  Mycorrhizal species richness and host ranges were investigated in mixed deciduous stands composed of Fagus sylvatica, Tilia spp., Carpinus betulus, Acer spp., and Fraxinus excelsior. Acer and Fraxinus were colonized by arbuscular mycorrhizas and contributed 5% to total stand mycorrhizal fungal species richness. Tilia hosted similar and Carpinus half the number of ectomycorrhizal (EM) fungal taxa compared with Fagus (75

Christa Lang; Jasmin Seven; Andrea Polle



Variable conductivity and embolism in roots and branches of four contrasting tree species and their impacts on whole-plant hydraulic performance under future atmospheric CO? concentration.  


Anatomical and physiological acclimation to water stress of the tree hydraulic system involves trade-offs between maintenance of stomatal conductance and loss of hydraulic conductivity, with short-term impacts on photosynthesis and long-term conseque