WorldWideScience

Sample records for host tree species

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-03-16

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

  3. Microenvironment in the canopy rivals the host tree water status in controlling sap flow of a mistletoe species.

    Science.gov (United States)

    Yang, Da; Goldstein, Guillermo; Wang, Miao; Zhang, Wei-Wei; Wang, Ai-Ying; Liu, Yan-Yan; Hao, Guang-You

    2017-04-01

    Mistletoes absorb water from the vascular system of their hosts and thus the water use of mistletoes can be influenced by the water status of their hosts besides abiotic environmental conditions; however, there is a lack of studies on the dynamics of mistletoe water utilization in relation to both types of controlling factors. By building a canopy platform at 20 m above the ground, we monitored the dynamic changes of sap flow of Viscum coloratum (Kom.) Nakai (Loranthaceae) in combination with continuous measurements of microclimatic variables and volumetric water content (VWC) of its host tree branch xylem. We found that the host tree VWC exhibited substantial fluctuations during sunny days but lower VWC of the host did not negatively affect the sap flow of V. coloratum. Hourly and daily mean transpiration rates (Esap) of V. coloratum calculated from sap flow measurements showed strong positive correlations with photosynthetic photon flux density (PPFD) and vapor pressure deficit (VPD) measured in close vicinity to the point of mistletoe attachment. The mean Esap of V. coloratum was substantially higher than that of their host during clear days (4.55 ± 0.54 vs 2.01 ± 0.15 kg m-2 day-1). Moreover, the mistletoe-to-host transpiration ratio was not constant but became increasingly larger with the increase of PPFD or VPD on both hourly and daily bases, suggesting a weaker control of water loss in the mistletoe in comparison to its host species. The strong dependence of mistletoe Esap on micrometeorological variables and its decoupling from the host tree xylem water status suggests that the development of dense tree canopy functions as a potential mechanism for the host trees in reducing the competitive water use of mistletoes. These findings have important implications for the interactions between mistletoe species and their host trees in temperate forests. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email

  4. North American tree squirrels and ground squirrels with overlapping ranges host different Cryptosporidium species and genotypes

    Czech Academy of Sciences Publication Activity Database

    Stenger, B.L.S.; Clark, M.E.; Kváč, Martin; Khan, E.; Giddings, C.W.; Prediger, Jitka; McEvoy, J.M.

    2015-01-01

    Roč. 36, 2015-Dec (2015), s. 287-293 ISSN 1567-1348 R&D Projects: GA ČR GA15-01090S Institutional support: RVO:60077344 Keywords : Cryptosporidium * Tree squirrels * Ground squirrels * Host specificity * Zoonotic Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.591, year: 2015

  5. Native trees of the Northeast Argentine: natural hosts of the Cryptococcus neoformans-Cryptococcus gattii species complex.

    Science.gov (United States)

    Cattana, Maria Emilia; Sosa, María de Los Ángeles; Fernández, Mariana; Rojas, Florencia; Mangiaterra, Magdalena; Giusiano, Gustavo

    2014-01-01

    In Argentina, information about epidemiology and environmental distribution of Cryptococcus is scarce. The city of Resistencia borders with Brazil and Paraguay where this fungus is endemic. All these supported the need to investigate the ecology of the genus and the epidemiology of cryptococcosis in this area. The aim was to investigate the presence of species of Cryptococcus neoformans-Cryptococcus gattii complex and their genotypes in trees of the city of Resistencia. One hundred and five trees were sampled by swabbing technique. The isolates were identified using conventional and commercial methods and genotyped by PCR-RFLP (Restriction Fragment Length Polymorphism). Cryptococcus was found in 7 out of the total trees. 6 out of 7 Cryptococcus isolates were identified as C. neoformans and one as C. gattii. C. gattii was isolated from Grevillea robusta. C. neoformans strains were isolated from Tabebuia avellanedae and Peltophorum dubium. Genotyping showed that all C. neoformans belonged to the VNI type and C. gattii belonged to the VGI type. This represents the first study on the ecology of Cryptococcus spp. associated to trees from northeastern Argentina, and the first report describing Grevillea robusta as a host of members of this fungal genus. Another finding is the isolation of C. neoformans from Tabebuia avellanedae and Peltophorum dubium, both tree species native to northeastern Argentina. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  6. Effect of host tree species on cellulase activity and bacterial community composition in the gut of larval Asian longhorned beetle.

    Science.gov (United States)

    Geib, Scott M; Jimenez-Gasco, Maria Del Mar; Carlson, John E; Tien, Ming; Hoover, Kelli

    2009-06-01

    Anoplophora glabripennis, the Asian longhorned beetle, is a wood-boring insect that can develop in a wide range of healthy deciduous hosts and requires gut microbes to aid in wood degradation and digestion. Here we show that larval A. glabripennis harbor a diverse gut bacterial community, and this community can be extremely variable when reared in different host trees. A. glabripennis reared in a preferred host (Acer saccharum) had the highest gut bacterial diversity compared with larvae reared either in a secondary host (Quercus palustris), a resistant host (Pyrus calleryana), or on artificial diet. The gut microbial community of larval A. glabripennis collected from field populations on Brooklyn, NY, showed the highest degree of complexity among all samples in this study. Overall, when larvae fed on a preferred host, they harbored a broad diversity of gut bacteria spanning the alpha-, beta-, gamma-Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Cellulase activities (beta-1,4-endoglucanase, beta-1,4-exoglucanase, and beta-1,4-glucosidase) in the guts of larvae fed in a preferred host (A. saccharum) or a secondary host (Q. palustris) were significantly higher than that of artificial diet fed larvae. Larvae that fed on wood from a resistant host (P. calleryana) showed suppressed total gut cellulase activity. Results show that the host tree can impact both gut microbial community complexity and cellulase activity in A. glabripennis.

  7. Novel Paraconiothyrium species on stone fruit trees and other woody hosts

    NARCIS (Netherlands)

    Damm, U.; Verkley, G.J.M.; Crous, P.W.; Fourie, P.H.; Haegi, A.; Riccioni, L.

    2008-01-01

    Coniothyrium-like fungi are common wood and soil inhabitants and hyperparasites on other fungi. They belong to different fungal genera within the Pleosporales. Several isolates were obtained on wood of different Prunus species (plum, peach and nectarine) from South Africa, on Actinidia species from

  8. Novel Paraconiothyrium species on stone fruit trees and other woody hosts

    NARCIS (Netherlands)

    Damm, U; Verkley, G J M; Crous, P W; Fourie, P H; Haegi, A; Riccioni, L

    Coniothyrium-like fungi are common wood and soil inhabitants and hyperparasites on other fungi. They belong to different fungal genera within the Pleosporales. Several isolates were obtained on wood of different Prunus species (plum, peach and nectarine) from South Africa, on Actinidia species from

  9. Genetic and morphological diversity of Trisetacus species (Eriophyoidea: Phytoptidae) associated with coniferous trees in Poland: phylogeny, barcoding, host and habitat specialization.

    Science.gov (United States)

    Lewandowski, Mariusz; Skoracka, Anna; Szydło, Wiktoria; Kozak, Marcin; Druciarek, Tobiasz; Griffiths, Don A

    2014-08-01

    Eriophyoid species belonging to the genus Trisetacus are economically important as pests of conifers. A narrow host specialization to conifers and some unique morphological characteristics have made these mites interesting subjects for scientific inquiry. In this study, we assessed morphological and genetic variation of seven Trisetacus species originating from six coniferous hosts in Poland by morphometric analysis and molecular sequencing of the mitochondrial cytochrome oxidase subunit I gene and the nuclear D2 region of 28S rDNA. The results confirmed the monophyly of the genus Trisetacus as well as the monophyly of five of the seven species studied. Both DNA sequences were effective in discriminating between six of the seven species tested. Host-dependent genetic and morphological variation in T. silvestris and T. relocatus, and habitat-dependent genetic and morphological variation in T. juniperinus were detected, suggesting the existence of races or even distinct species within these Trisetacus taxa. This is the first molecular phylogenetic analysis of the Trisetacus species. The findings presented here will stimulate further investigations on the evolutionary relationships of Trisetacus as well as the entire Phytoptidae family.

  10. Mitochondrial COI and morphological evidence for host specificity of the black cherry aphids Myzus cerasi (Fabricius, 1775) collected from different cherry tree species in Europe (Hemiptera, Aphididae).

    Science.gov (United States)

    Rakauskas, Rimantas; Havelka, Jekaterina; Zaremba, Audrius; Bernotienė, Rasa

    2014-01-01

    Partial sequences of the mitochondrial COI gene of forty eight European and two Turkish population samples of Myzus cerasi from different winter hosts (Prunus spp.) were subjected to phylogenetic analyses. The analysed M. cerasi samples emerged as paraphyletic relative to a Myzus borealis sample used as an out-group, and formed two major clades in neighbor joining, maximum parsimony, maximum likelihood and Bayesian inference trees, corresponding to subspecies living specifically on Prunus avium and P. cerasus. Multivariate discriminant analysis (method of canonical variates) was applied to find out if morphological variation of samples correlated with mitochondrial COI and host plant information. Mean scores on the first two canonical variables clustered samples fully in accordance with their COI haplotypes and host plants confirming the existence of two morphologically similar winter host - specific subspecies of M. cerasi in Europe. No single morphological character enabled satisfactory discrimination between apterous viviparous females of the two subspecies. A three-character linear discriminant function enabled 92.37% correct identification of apterous viviparous females of M. cerasi cerasi (n = 118) and 93.64% of M. cerasi pruniavium (n = 110). A key for the morphological identification of the two subspecies is presented and their taxonomic status is discussed.

  11. Mitochondrial COI and morphological evidence for host specificity of the black cherry aphids Myzus cerasi (Fabricius, 1775 collected from different cherry tree species in Europe (Hemiptera, Aphididae

    Directory of Open Access Journals (Sweden)

    Rimantas Rakauskas

    2014-03-01

    Full Text Available Partial sequences of the mitochondrial COI gene of forty eight European and two Turkish population samples of Myzus cerasi from different winter hosts (Prunus spp. were subjected to phylogenetic analyses. The analysed M. cerasi samples emerged as paraphyletic relative to a Myzus borealis sample used as an out-group, and formed two major clades in neighbor joining, maximum parsimony, maximum likelihood and Bayesian inference trees, corresponding to subspecies living specifically on Prunus avium and P. cerasus. Multivariate discriminant analysis (method of canonical variates was applied to find out if morphological variation of samples correlated with mitochondrial COI and host plant information. Mean scores on the first two canonical variables clustered samples fully in accordance with their COI haplotypes and host plants confirming the existence of two morphologically similar winter host - specific subspecies of M.cerasi in Europe. No single morphological character enabled satisfactory discrimination between apterous viviparous females of the two subspecies. A three-character linear discriminant function enabled 92.37% correct identification of apterous viviparous females of M. cerasi cerasi (n=118 and 93.64% of M. cerasi pruniavium (n=110. A key for the morphological identification of the two subspecies is presented and their taxonomic status is discussed.

  12. storey and canopy tree species

    African Journals Online (AJOL)

    different tree species. The data presented here would therefore help in the planning and management of tropical forest reserves and development of management inteiventions to enhance forest productivity and ecological balance. Materials and methods. Study site. Kalinzu Forest Reserve is a tropical rain forest locate<.! in.

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

    NARCIS (Netherlands)

    Eilmann, B.; Rigling, A.

    2012-01-01

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

  14. The Inference of Gene Trees with Species Trees

    Science.gov (United States)

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

    2015-01-01

    This article reviews the various models that have been used to describe the relationships between gene trees and species trees. Molecular phylogeny has focused mainly on improving models for the reconstruction of gene trees based on sequence alignments. Yet, most phylogeneticists seek to reveal the history of species. Although the histories of genes and species are tightly linked, they are seldom identical, because genes duplicate, are lost or horizontally transferred, and because alleles can coexist in populations for periods that may span several speciation events. Building models describing the relationship between gene and species trees can thus improve the reconstruction of gene trees when a species tree is known, and vice versa. Several approaches have been proposed to solve the problem in one direction or the other, but in general neither gene trees nor species trees are known. Only a few studies have attempted to jointly infer gene trees and species trees. These models account for gene duplication and loss, transfer or incomplete lineage sorting. Some of them consider several types of events together, but none exists currently that considers the full repertoire of processes that generate gene trees along the species tree. Simulations as well as empirical studies on genomic data show that combining gene tree–species tree models with models of sequence evolution improves gene tree reconstruction. In turn, these better gene trees provide a more reliable basis for studying genome evolution or reconstructing ancestral chromosomes and ancestral gene sequences. We predict that gene tree–species tree methods that can deal with genomic data sets will be instrumental to advancing our understanding of genomic evolution. PMID:25070970

  15. Two mistletoes are too many?: Interspecific occurrence of mistletoes on the same host tree

    Directory of Open Access Journals (Sweden)

    Rafael Arruda

    2013-03-01

    Full Text Available Mistletoe can have a major impact on the fitness of the host plant. If there is more than one species of mistletoe on the same host tree, the overall impact might be amplified. We report the occurrence of more than one species of mistletoe on the same host tree. Although it is not a rule in the field, to our knowledge, there have been no studies of this topic. In most cases, two species of mistletoe were recorded on the same host tree, although we recorded three species of mistletoe on one occasion. This demonstrates that different species of mistletoe can be compatible with the same host species. Therefore, compatibility (structural and physiological might be an important factor for the occurrence of mistletoe. Recent studies have shown that if the mistletoe does not "recognize" the host species, the deposited seeds will germinate but the haustorium will not penetrate the host branch. This is probably the primary mechanism in the establishment of more than one species of mistletoe on the same host, which can trigger a cascade of harmful effects for the host species.

  16. Demography of threatened tree species in Vietnam

    NARCIS (Netherlands)

    Chien, P.D.

    2006-01-01

    Demography of threatened tree species in Vietnam (Summary for the library) Effective conservation of threatened tree species requires information on natural dynamics and future prospects of populations of these species. Such information can be obtained from demographic studies. We investigated the

  17. Host tree influences on longicorn beetle (Coleoptera: Cerambycidae) attack in subtropical Corymbia (Myrtales: Myrtaceae).

    Science.gov (United States)

    Nahrung, Helen F; Smith, Timothy E; Wiegand, Aaron N; Lawson, Simon A; Debuse, Valerie J

    2014-02-01

    Phoracantha longicorn beetles are endemic to Australia, and some species have become significant pests of eucalypts worldwide, yet little is known about their host plant interactions and factors influencing tree susceptibility in Australia. Here, we investigate the host relationships of Phoracantha solida (Blackburn, 1894) on four eucalypt taxa (one pure species and three hybrid families), examining feeding site physical characteristics including phloem thickness, density, and moisture content, and host tree factors such as diameter, height, growth, taper, and survival. We also determine the cardinal and vertical (within-tree) and horizontal (between-tree) spatial distribution of borers. Fewer than 10% of P. solida attacks were recorded from the pure species (Corymbia citriodora subsp. variegate (Hook)), and this taxon also showed the highest survival, phloem thickness, relative growth rate, and bark:wood area. For the two most susceptible taxa, borer severity was negatively correlated with moisture content, and positively related to phloem density. Borers were nonrandomly and nonuniformly distributed within trees, and were statistically aggregated in 32% of plots. More attacks were situated on the northern side of the tree than the other aspects, and most larvae fed within the lower 50 cm of the bole, with attack height positively correlated with severity. Trees with borers had more dead neighbors, and more bored neighbors, than trees without borers, while within plots, borer incidence and severity were positively correlated. Because the more susceptible taxa overlapped with less susceptible taxa for several physical tree factors, the role of primary and secondary chemistries in determining host suitability needs to be investigated. Nevertheless, taxon, moisture content, phloem density, tree size, and mortality of neighboring trees appeared the most important physical characteristics influencing host suitability for P. solida at this site.

  18. Big data of tree species distributions

    DEFF Research Database (Denmark)

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

    2018-01-01

    are currently available in big databases, several challenges hamper their use, notably geolocation problems and taxonomic uncertainty. Further, we lack a complete picture of the data coverage and quality assessment for open/public databases of tree occurrences. Methods: We combined data from five major....... Conclusions: Our geographical coverage analysis shows that a wealth of easily accessible data exist on tree species occurrences worldwide, but regional gaps and coordinate errors are abundant. Thus, assessment of tree distributions will need accurate occurrence quality control protocols and key collaborations......Background: Trees play crucial roles in the biosphere and societies worldwide, with a total of 60,065 tree species currently identified. Increasingly, a large amount of data on tree species occurrences is being generated worldwide: from inventories to pressed plants. While many of these data...

  19. Trees Wanted—Dead or Alive! Host Selection and Population Dynamics in Tree-Killing Bark Beetles

    Science.gov (United States)

    Kausrud, Kyrre L.; Grégoire, Jean-Claude; Skarpaas, Olav; Erbilgin, Nadir; Gilbert, Marius; Økland, Bjørn; Stenseth, Nils Chr.

    2011-01-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) feed and breed in dead or severely weakened host trees. When their population densities are high, some species aggregate on healthy host trees so that their defences may be exhausted and the inner bark successfully colonized, killing the tree in the process. Here we investigate under what conditions participating with unrelated conspecifics in risky mass attacks on living trees is an adaptive strategy, and what this can tell us about bark beetle outbreak dynamics. We find that the outcome of individual host selection may deviate from the ideal free distribution in a way that facilitates the emergence of tree-killing (aggressive) behavior, and that any heritability on traits governing aggressiveness seems likely to exist in a state of flux or cycles consistent with variability observed in natural populations. This may have implications for how economically and ecologically important species respond to environmental changes in climate and landscape (forest) structure. The population dynamics emerging from individual behavior are complex, capable of switching between “endemic” and “epidemic” regimes spontaneously or following changes in host availability or resistance. Model predictions are compared to empirical observations, and we identify some factors determining the occurrence and self-limitation of epidemics. PMID:21647433

  20. Trees wanted--dead or alive! Host selection and population dynamics in tree-killing bark beetles.

    Science.gov (United States)

    Kausrud, Kyrre L; Grégoire, Jean-Claude; Skarpaas, Olav; Erbilgin, Nadir; Gilbert, Marius; Økland, Bjørn; Stenseth, Nils Chr

    2011-01-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) feed and breed in dead or severely weakened host trees. When their population densities are high, some species aggregate on healthy host trees so that their defences may be exhausted and the inner bark successfully colonized, killing the tree in the process. Here we investigate under what conditions participating with unrelated conspecifics in risky mass attacks on living trees is an adaptive strategy, and what this can tell us about bark beetle outbreak dynamics. We find that the outcome of individual host selection may deviate from the ideal free distribution in a way that facilitates the emergence of tree-killing (aggressive) behavior, and that any heritability on traits governing aggressiveness seems likely to exist in a state of flux or cycles consistent with variability observed in natural populations. This may have implications for how economically and ecologically important species respond to environmental changes in climate and landscape (forest) structure. The population dynamics emerging from individual behavior are complex, capable of switching between "endemic" and "epidemic" regimes spontaneously or following changes in host availability or resistance. Model predictions are compared to empirical observations, and we identify some factors determining the occurrence and self-limitation of epidemics.

  1. Trees wanted--dead or alive! Host selection and population dynamics in tree-killing bark beetles.

    Directory of Open Access Journals (Sweden)

    Kyrre L Kausrud

    Full Text Available Bark beetles (Coleoptera: Curculionidae, Scolytinae feed and breed in dead or severely weakened host trees. When their population densities are high, some species aggregate on healthy host trees so that their defences may be exhausted and the inner bark successfully colonized, killing the tree in the process. Here we investigate under what conditions participating with unrelated conspecifics in risky mass attacks on living trees is an adaptive strategy, and what this can tell us about bark beetle outbreak dynamics. We find that the outcome of individual host selection may deviate from the ideal free distribution in a way that facilitates the emergence of tree-killing (aggressive behavior, and that any heritability on traits governing aggressiveness seems likely to exist in a state of flux or cycles consistent with variability observed in natural populations. This may have implications for how economically and ecologically important species respond to environmental changes in climate and landscape (forest structure. The population dynamics emerging from individual behavior are complex, capable of switching between "endemic" and "epidemic" regimes spontaneously or following changes in host availability or resistance. Model predictions are compared to empirical observations, and we identify some factors determining the occurrence and self-limitation of epidemics.

  2. Removing other Tree Species does not benefit the Timber Species ...

    African Journals Online (AJOL)

    The endemic canopy tree Cephalosphaera usambarensis is a valuable timber species in montane rainforest of Tanzania. Here we evaluate an experiment in which mature trees of species other than C. usambarensis were removed from an area in the East Usambara Mountains. We compared stage/size structure of the ...

  3. Reconciliation of Gene and Species Trees

    Directory of Open Access Journals (Sweden)

    L. Y. Rusin

    2014-01-01

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

  4. Do parasitic trematode cercariae demonstrate a preference for susceptible host species?

    Directory of Open Access Journals (Sweden)

    Brittany F Sears

    Full Text Available Many parasites are motile and exhibit behavioural preferences for certain host species. Because hosts can vary in their susceptibility to infections, parasites might benefit from preferentially detecting and infecting the most susceptible host, but this mechanistic hypothesis for host-choice has rarely been tested. We evaluated whether cercariae (larval trematode parasites prefer the most susceptible host species by simultaneously presenting cercariae with four species of tadpole hosts. Cercariae consistently preferred hosts in the following order: Anaxyrus ( = Bufo terrestris (southern toad, Hyla squirella (squirrel tree frog, Lithobates ( = Rana sphenocephala (southern leopard frog, and Osteopilus septentrionalis (Cuban tree frog. These host species varied in susceptibility to cercariae in an order similar to their attractiveness with a correlation that approached significance. Host attractiveness to parasites also varied consistently and significantly among individuals within a host species. If heritable, this individual-level host variation would represent the raw material upon which selection could act, which could promote a Red Queen "arms race" between host cues and parasite detection of those cues. If, in general, motile parasites prefer to infect the most susceptible host species, this phenomenon could explain aggregated distributions of parasites among hosts and contribute to parasite transmission rates and the evolution of virulence. Parasite preferences for hosts belie the common assumption of disease models that parasites seek and infect hosts at random.

  5. Species tree inference by minimizing deep coalescences.

    Directory of Open Access Journals (Sweden)

    Cuong Than

    2009-09-01

    Full Text Available In a 1997 seminal paper, W. Maddison proposed minimizing deep coalescences, or MDC, as an optimization criterion for inferring the species tree from a set of incongruent gene trees, assuming the incongruence is exclusively due to lineage sorting. In a subsequent paper, Maddison and Knowles provided and implemented a search heuristic for optimizing the MDC criterion, given a set of gene trees. However, the heuristic is not guaranteed to compute optimal solutions, and its hill-climbing search makes it slow in practice. In this paper, we provide two exact solutions to the problem of inferring the species tree from a set of gene trees under the MDC criterion. In other words, our solutions are guaranteed to find the tree that minimizes the total number of deep coalescences from a set of gene trees. One solution is based on a novel integer linear programming (ILP formulation, and another is based on a simple dynamic programming (DP approach. Powerful ILP solvers, such as CPLEX, make the first solution appealing, particularly for very large-scale instances of the problem, whereas the DP-based solution eliminates dependence on proprietary tools, and its simplicity makes it easy to integrate with other genomic events that may cause gene tree incongruence. Using the exact solutions, we analyze a data set of 106 loci from eight yeast species, a data set of 268 loci from eight Apicomplexan species, and several simulated data sets. We show that the MDC criterion provides very accurate estimates of the species tree topologies, and that our solutions are very fast, thus allowing for the accurate analysis of genome-scale data sets. Further, the efficiency of the solutions allow for quick exploration of sub-optimal solutions, which is important for a parsimony-based criterion such as MDC, as we show. We show that searching for the species tree in the compatibility graph of the clusters induced by the gene trees may be sufficient in practice, a finding that helps

  6. Phylogenetic isolation of host trees affects assembly of local Heteroptera communities

    Science.gov (United States)

    Vialatte, A.; Bailey, R. I.; Vasseur, C.; Matocq, A.; Gossner, M. M.; Everhart, D.; Vitrac, X.; Belhadj, A.; Ernoult, A.; Prinzing, A.

    2010-01-01

    A host may be physically isolated in space and then may correspond to a geographical island, but it may also be separated from its local neighbours by hundreds of millions of years of evolutionary history, and may form in this case an evolutionarily distinct island. We test how this affects the assembly processes of the host's colonizers, this question being until now only invoked at the scale of physically distinct islands or patches. We studied the assembly of true bugs in crowns of oaks surrounded by phylogenetically more or less closely related trees. Despite the short distances (less than 150 m) between phylogenetically isolated and non-isolated trees, we found major differences between their Heteroptera faunas. We show that phylogenetically isolated trees support smaller numbers and fewer species of Heteroptera, an increasing proportion of phytophages and a decreasing proportion of omnivores, and proportionally more non-host-specialists. These differences were not due to changes in the nutritional quality of the trees, i.e. species sorting, which we accounted for. Comparison with predictions from meta-community theories suggests that the assembly of local Heteroptera communities may be strongly driven by independent metapopulation processes at the level of the individual species. We conclude that the assembly of communities on hosts separated from their neighbours by long periods of evolutionary history is qualitatively and quantitatively different from that on hosts established surrounded by closely related trees. Potentially, the biotic selection pressure on a host might thus change with the evolutionary proximity of the surrounding hosts. PMID:20335208

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

    Science.gov (United States)

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

    2012-11-15

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

  8. Pushing the pace of tree species migration.

    Directory of Open Access Journals (Sweden)

    Eli D Lazarus

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

  9. Pushing the pace of tree species migration.

    Science.gov (United States)

    Lazarus, Eli D; McGill, Brian J

    2014-01-01

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

  10. Isoprene emission from tropical tree species

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-05-01

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

  11. Host-Tree Monoterpenes and Biosynthesis of Aggregation Pheromones in the Bark Beetle Ips paraconfusus

    Directory of Open Access Journals (Sweden)

    John A. Byers

    2012-01-01

    Full Text Available A paradigm developed in the 1970s that Ips bark beetles biosynthesize their aggregation pheromone components ipsenol and ipsdienol by hydroxylating myrcene, a host tree monoterpene. Similarly, host α-pinene was hydroxylated to a third pheromone component cis-verbenol. In 1990, however, we reported that amounts of ipsenol and ipsdienol produced by male Ips paraconfusus (Coleoptera: Scolytinae feeding in five host pine species were nearly the same, even though no detectable myrcene precursor was detected in one of these pines (Pinus sabiniana. Subsequent research showed ipsenol and ipsdienol are also biosynthesized from smaller precursors such as acetate and mevalonate, and this de novo pathway is the major one, while host tree myrcene conversion by the beetle is the minor one. We report concentrations of myrcene, α-pinene and other major monoterpenes in five pine hosts (Pinus ponderosa, P. lambertiana, P. jeffreyi, P. sabiniana, and P. contorta of I. paraconfusus. A scheme for biosynthesis of ipsdienol and ipsenol from myrcene and possible metabolites such as ipsenone is presented. Mass spectra and quantities of ipsenone are reported and its possible role in biosynthesis of aggregation pheromone. Coevolution of bark beetles and host trees is discussed in relation to pheromone biosynthesis, host plant selection/suitability, and plant resistance.

  12. Ecological interactions of bark beetles with host trees

    Science.gov (United States)

    Certain species of bark beetles in the insect order Coleoptera, family Curculionidae (formerly Scolytidae) are keystone species in forest ecosystems. However, the tree-killing and woodboring bark and ambrosia beetles are also among the most damaging insects of forest products including lumber, paper...

  13. Vascular epiphytes and host trees of ant-gardens in an anthropic landscape in southeastern Mexico

    Science.gov (United States)

    Morales-Linares, Jonas; García-Franco, José G.; Flores-Palacios, Alejandro; Valenzuela-González, Jorge E.; Mata-Rosas, Martín; Díaz-Castelazo, Cecilia

    2016-12-01

    Ant-gardens (AGs) are considered one of the most complex mutualist systems between ants and plants, since interactions involving dispersal, protection, and nutrition occur simultaneously in them; however, little is known about the effects of the transformation of ecosystems on their diversity and interactions. In five environments with different land use within an anthropic landscape in southeastern Mexico, we investigated the diversity and composition of epiphytes and host trees of AGs built by Azteca gnava. A total of 10,871 individuals of 26 epiphytic species, associating with 859 AGs located in 161 host trees, were recorded. The diversity and composition of epiphytes tended to be different between environments; however, Aechmea tillandsioides and Codonanthe uleana were the most important species and considered true AG epiphytes, because they were the most frequent, abundant, and occurred exclusively in AGs. Other important species were the orchids Epidendrum flexuosum, Coryanthes picturata, and Epidendrum pachyrachis, and should also be considered true AG epiphytes, because they occurred almost exclusively in the AGs. The AG abundance in agroforestry plantations was similar or even greater than in riparian vegetation (natural habitat). The AGs were registered in 37 host species but were more frequent in Mangifera indica and Citrus sinensis. We conclude that true epiphytes of A. gnava AGs persist in different environments and host trees, and even these AGs could proliferate in agroforestry plantations of anthropic landscapes.

  14. Tree Species Identity Shapes Earthworm Communities

    DEFF Research Database (Denmark)

    Schelfhout, Stephanie; Mertens, Jan; Verheyen, Kris

    2017-01-01

    of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer...... and Tilia, which is related to calcium-rich litter and low soil acidification. Epigeic earthworms were indifferent to calcium content in leaf litter and were shown to be mainly related to soil moisture content and litter C:P ratios. Almost no earthworms were found in Picea stands, likely because......Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden...

  15. Canopy soil bacterial communities altered by severing host tree limbs

    Directory of Open Access Journals (Sweden)

    Cody R. Dangerfield

    2017-09-01

    Full Text Available Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities.

  16. Tree Species Identity Shapes Earthworm Communities

    Directory of Open Access Journals (Sweden)

    Stephanie Schelfhout

    2017-03-01

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

  17. Enumeration of Ancestral Configurations for Matching Gene Trees and Species Trees.

    Science.gov (United States)

    Disanto, Filippo; Rosenberg, Noah A

    2017-09-01

    Given a gene tree and a species tree, ancestral configurations represent the combinatorially distinct sets of gene lineages that can reach a given node of the species tree. They have been introduced as a data structure for use in the recursive computation of the conditional probability under the multispecies coalescent model of a gene tree topology given a species tree, the cost of this computation being affected by the number of ancestral configurations of the gene tree in the species tree. For matching gene trees and species trees, we obtain enumerative results on ancestral configurations. We study ancestral configurations in balanced and unbalanced families of trees determined by a given seed tree, showing that for seed trees with more than one taxon, the number of ancestral configurations increases for both families exponentially in the number of taxa n. For fixed n, the maximal number of ancestral configurations tabulated at the species tree root node and the largest number of labeled histories possible for a labeled topology occur for trees with precisely the same unlabeled shape. For ancestral configurations at the root, the maximum increases with [Formula: see text], where [Formula: see text] is a quadratic recurrence constant. Under a uniform distribution over the set of labeled trees of given size, the mean number of root ancestral configurations grows with [Formula: see text] and the variance with ∼[Formula: see text]. The results provide a contribution to the combinatorial study of gene trees and species trees.

  18. An estimate of the number of tropical tree species

    Science.gov (United States)

    J. W. Ferry Slik; Victor Arroyo-Rodriguez; Shin-Ichiro and others. Aiba

    2015-01-01

    The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fishers alpha and an approximate pantropical stem...

  19. Survey Of Indigenous Tree Species In Osun Sacred Grove, Osun ...

    African Journals Online (AJOL)

    A botanical survey of indigenous tree species present in core regions of the Osun sacred grove, Osun state, Nigeria,was conducted. A total of eighty (80) tree species belonging to sixty-six (66) genera and twenty seven (27) families were identified and recorded. The family Fabaceae had the largest number of tree species ...

  20. Inferring rooted species trees from unrooted gene trees using approximate Bayesian computation.

    Science.gov (United States)

    Alanzi, Ayed R A; Degnan, James H

    2017-11-01

    Methods for inferring species trees from gene trees motivated by incomplete lineage sorting typically use either rooted gene trees to infer a rooted species tree, or use unrooted gene trees to infer an unrooted species tree, which is then typically rooted using one or more outgroups. Theoretically, however, it has been known since 2011 that it is possible to consistently infer the root of the species tree directly from unrooted gene trees without assuming an outgroup. Here, we use approximate Bayesian computation to infer the root of the species tree from unrooted gene trees assuming the multispecies coalescent model. It is hoped that this approach will be useful in cases where an appropriate outgroup is difficult to find and gene trees do not follow a molecular clock. We use approximate Bayesian computation to infer the root of the species tree from unrooted gene trees. This approach could also be useful when there is prior information that makes a small number of root locations plausible in an unrooted species tree. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Codivergence and multiple host species use by fig wasp populations of the Ficus pollination mutualism

    Directory of Open Access Journals (Sweden)

    McLeish Michael J

    2012-01-01

    Full Text Available Abstract Background The interaction between insects and plants takes myriad forms in the generation of spectacular diversity. In this association a species host range is fundamental and often measured using an estimate of phylogenetic concordance between species. Pollinating fig wasps display extreme host species specificity, but the intraspecific variation in empirical accounts of host affiliation has previously been underestimated. In this investigation, lineage delimitation and codiversification tests are used to generate and discuss hypotheses elucidating on pollinating fig wasp associations with Ficus. Results Statistical parsimony and AMOVA revealed deep divergences at the COI locus within several pollinating fig wasp species that persist on the same host Ficus species. Changes in branching patterns estimated using the generalized mixed Yule coalescent test indicated lineage duplication on the same Ficus species. Conversely, Elisabethiella and Alfonsiella fig wasp species are able to reproduce on multiple, but closely related host fig species. Tree reconciliation tests indicate significant codiversification as well as significant incongruence between fig wasp and Ficus phylogenies. Conclusions The findings demonstrate more relaxed pollinating fig wasp host specificity than previously appreciated. Evolutionarily conservative host associations have been tempered by horizontal transfer and lineage duplication among closely related Ficus species. Independent and asynchronistic diversification of pollinating fig wasps is best explained by a combination of both sympatric and allopatric models of speciation. Pollinator host preference constraints permit reproduction on closely related Ficus species, but uncertainty of the frequency and duration of these associations requires better resolution.

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

    African Journals Online (AJOL)

    ... tree species encountered were threatened/endangered, 23 species were rare with only 3 tree species (Brachystegia eurycoma, Bailonella toxisperma and Ceiba pentandra) being abundant in the area. Frequent and occasional species were not encountered in the area. Leguminoseae was the most represented family ...

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

    Directory of Open Access Journals (Sweden)

    QUEIROZ J. M.

    2002-01-01

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

  4. An estimate of the number of tropical tree species

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  5. Role of volatile and non-volatile plant secondary metabolites in host tree selection by Christmas beetles.

    Science.gov (United States)

    Matsuki, Mamoru; Foley, William J; Floyd, Robert B

    2011-03-01

    Individual Eucalyptus trees in south-eastern Australia vary considerably in susceptibility to herbivores. On the one hand, studies with insect herbivores have suggested that variation in the concentrations of foliar monoterpenes is related to variation in susceptibility. On the other, studies with marsupial folivores have suggested that variation in the concentrations of sideroxylonals (a group of formylated phloroglucinol compounds) is responsible for variation in susceptibility. We examined relative importance of sideroxylonals and 1,8-cineole (a dominant monoterpene) in host tree selection by Christmas beetles (Anoplognathus species: Coleoptera: Scarabaeidae) by using no-choice experiments, choice/no-choice experiments, and manipulative experiments in which concentrations of sideroxylonals or 1,8-cineole were altered. We used two species of host Eucalyptus, one species of non-host Eucalyptus, and three species of non-host non-Eucalyptus trees. Leaf consumption by Christmas beetles was negatively correlated with the concentrations of sideroxylonals and 1,8-cineole. Artificial increases in the concentration of sideroxylonals or 1,8-cineole reduced leaf consumption by Christmas beetles. An artificial reduction in foliar monoterpenes had no effect on leaf consumption by the beetles when leaves contained high or very low concentrations of sideroxylonals. However, when the concentration of sideroxylonals was moderate, a reduction in the foliar monoterpenes increased leaf consumption by the beetles. Therefore, monoterpenes such as 1,8-cineole may be used as a negative cue by Christmas beetles. The pattern of food consumption on non-host Eucalyptus species and non-host non-Eucalyptus species suggest that both positive and negative cues may be used by Christmas beetles to select host trees.

  6. Isoprene emission capacity for US tree species

    Science.gov (United States)

    Geron, Chris; Harley, Peter; Guenther, Alex

    -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 μg C g -1 h -1) or very high (˜100 μg C g -1 h -1) genetic capacity to emit isoprene when mature foliage is exposed to a high ambient temperature and light environment.

  7. Tree species, tree genotypes and tree genotypic diversity levels affect microbe-mediated soil ecosystem functions in a subtropical forest

    Science.gov (United States)

    Purahong, Witoon; Durka, Walter; Fischer, Markus; Dommert, Sven; Schöps, Ricardo; Buscot, François; Wubet, Tesfaye

    2016-11-01

    Tree species identity and tree genotypes contribute to the shaping of soil microbial communities. However, knowledge about how these two factors influence soil ecosystem functions is still lacking. Furthermore, in forest ecosystems tree genotypes co-occur and interact with each other, thus the effects of tree genotypic diversity on soil ecosystem functions merit attention. Here we investigated the effects of tree species, tree genotypes and genotypic diversity levels, alongside soil physicochemical properties, on the overall and specific soil enzyme activity patterns. Our results indicate that tree species identity, tree genotypes and genotypic diversity level have significant influences on overall and specific soil enzyme activity patterns. These three factors influence soil enzyme patterns partly through effects on soil physicochemical properties and substrate quality. Variance partitioning showed that tree species identity, genotypic diversity level, pH and water content all together explained ~30% variations in the overall patterns of soil enzymes. However, we also found that the responses of soil ecosystem functions to tree genotypes and genotypic diversity are complex, being dependent on tree species identity and controlled by multiple factors. Our study highlights the important of inter- and intra-specific variations in tree species in shaping soil ecosystem functions in a subtropical forest.

  8. Exploring tree species signature using waveform LiDAR data

    Science.gov (United States)

    Zhou, T.; Popescu, S. C.; Krause, K.

    2015-12-01

    Successful classification of tree species with waveform LiDAR data would be of considerable value to estimate the biomass stocks and changes in forests. Current approaches emphasize converting the full waveform data into discrete points to get larger amount of parameters and identify tree species using several discrete-points variables. However, ignores intensity values and waveform shapes which convey important structural characteristics. The overall goal of this study was to employ the intensity and waveform shape of individual tree as the waveform signature to detect tree species. The data was acquired by the National Ecological Observatory Network (NEON) within 250*250 m study area located in San Joaquin Experimental Range. Specific objectives were to: (1) segment individual trees using the smoothed canopy height model (CHM) derived from discrete LiDAR points; (2) link waveform LiDAR with above individual tree boundaries to derive sample signatures of three tree species and use these signatures to discriminate tree species in a large area; and (3) compare tree species detection results from discrete LiDAR data and waveform LiDAR data. An overall accuracy of the segmented individual tree of more than 80% was obtained. The preliminary results show that compared with the discrete LiDAR data, the waveform LiDAR signature has a higher potential for accurate tree species classification.

  9. Carving out indigenous tree species to sustain rural livelihood ...

    African Journals Online (AJOL)

    However, the over-dependence on a few selected indigenous tree species for carving is a source of concern, threatening local livelihoods and survival of the industry. This study sought to investigate the sources, availability and sustainability of tree species used, awareness of alternative species for carving and the ...

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

    African Journals Online (AJOL)

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

  11. Infection of non-host model plant species with the narrow-host-range Cacao swollen shoot virus.

    Science.gov (United States)

    Friscina, Arianna; Chiappetta, Laura; Jacquemond, Mireille; Tepfer, Mark

    2017-02-01

    Cacao swollen shoot virus (CSSV) is a major pathogen of cacao (Theobroma cacao) in Africa, and long-standing efforts to limit its spread by the culling of infected trees have had very limited success. CSSV is a particularly difficult virus to study, as it has a very narrow host range, limited to several tropical tree species. Furthermore, the virus is not mechanically transmissible, and its insect vector can only be used with difficulty. Thus, the only efficient means to infect cacao plants that have been experimentally described so far are by particle bombardment or the agroinoculation of cacao plants with an infectious clone. We have genetically transformed three non-host species with an infectious form of the CSSV genome: two experimental hosts widely used in plant virology (Nicotiana tabacum and N. benthamiana) and the model species Arabidopsis thaliana. In transformed plants of all three species, the CSSV genome was able to replicate, and, in tobacco, CSSV particles could be observed by immunosorbent electron microscopy, demonstrating that the complete virus cycle could be completed in a non-host plant. These results will greatly facilitate the preliminary testing of CSSV control strategies using plants that are easy to raise and to transform genetically. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  12. Farmers' preferences for tree species on Agroforestry System in ...

    African Journals Online (AJOL)

    This study was conducted to generate information on tree species farmers are willing to retain or plant on their farms; the benefits they derive from the trees and the traditional management practices used for such trees in Ijebu North Local Government Area of Ogun State, in southwestern Nigeria. Multistage sampling ...

  13. Tree species richness affecting fine root biomass in European forests

    Science.gov (United States)

    Finér, Leena; Domisch, Timo; Vesterdal, Lars; Dawud, Seid M.; Raulund-Rasmussen, Karsten

    2016-04-01

    Fine roots are an important factor in the forest carbon cycle, contributing significantly to below-ground biomass and soil carbon storage. Therefore it is essential to understand the role of the forest structure, indicated by tree species diversity in controlling below-ground biomass and managing the carbon pools of forest soils. We studied how tree species richness would affect fine root biomass and its distribution in the soil profile and biomass above- and below-ground allocation patterns of different tree species. Our main hypothesis was that increasing tree species richness would lead to below-ground niche differentiation and more efficient soil exploitation by the roots, resulting in a higher fine root biomass in the soil. We sampled fine roots of trees and understorey vegetation in six European forest types in Finland, Poland, Germany, Romania, Italy and Spain, representing boreal, temperate and Mediterranean forests, established within the FunDivEUROPE project for studying the effects of tree species diversity on forest functioning. After determining fine root biomasses, we identified the percentages of different tree species in the fine root samples using the near infrared reflectance spectroscopy (NIRS) method. Opposite to our hypothesis we did not find any general positive relationship between tree species richness and fine root biomass. A weak positive response found in Italy and Spain seemed to be related to dry environmental conditions during Mediterranean summers. At the Polish site where we could sample deeper soil layers (down to 40 cm), we found more tree fine roots in the deeper layers under species-rich forests, as compared to the monocultures, indicating the ability of trees to explore more resources and to increase soil carbon stocks. Tree species richness did not affect biomass allocation patterns between above- and below-ground parts of the trees.

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  15. Phytophagy on phylogenetically isolated trees: why hosts should escape their relatives.

    NARCIS (Netherlands)

    Yguel, B.; Bailey, R.; Everhart, D.; Vialatte, A.; Vasseur, C.; Vitrac, X.; Prinzing, A.

    2011-01-01

    Hosts belonging to the same species suffer dramatically different impacts from their natural enemies. This has been explained by host neighbourhood, that is, by surrounding host-species diversity or spatial separation between hosts. However, even spatially neighbouring hosts may be separated by many

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

    Directory of Open Access Journals (Sweden)

    Michelle M McMahon

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

    Ethnobotanical survey of tree species used for wound healing in Ibadan, southwest Nigeria. ... The most frequently mentioned family is Fabaceae, followed by Meliaceae and Annonaceae. Stem barks were predominant in the ... Keywords: Wound healing, ethnobotanical survey, tree species, medicinal uses, conservation ...

  20. Anatomical studies of selected tree species of the Moraceae family ...

    African Journals Online (AJOL)

    Anatomical studies of selected tree species of the Moraceae family grown in Nigeria. CEC Ugwoke, GC Uju. Abstract. The internode, bark and wood anatomy of seven tree species of the Family Moraceae, grown in Nigeria were studied to determine their characteristic tissue distribution and unique ergastic substances which ...

  1. Seasonal drought limits tree species across the Neotropics

    NARCIS (Netherlands)

    Esquivel-Muelbert, Adriane; Baker, Timothy R.; Dexter, Kyle G.; Lewis, Simon L.; Steege, ter Hans; Lopez-Gonzalez, Gabriela; Monteagudo Mendoza, Abel; Brienen, Roel; Feldpausch, Ted R.; Pitman, Nigel; Alonso, Alfonso; Heijden, van der Geertje; Peña-Claros, Marielos; Ahuite, Manuel; Alexiaides, Miguel; Álvarez Dávila, Esteban; Murakami, Alejandro Araujo; Arroyo, Luzmila; Aulestia, Milton; Balslev, Henrik; Barroso, Jorcely; Boot, Rene; Cano, Angela; Chama Moscoso, Victor; Comiskey, James A.; Cornejo, Fernando; Dallmeier, Francisco; Daly, Douglas C.; Dávila, Nallarett; Duivenvoorden, Joost F.; Duque Montoya, Alvaro Javier; Erwin, Terry; Fiore, Di Anthony; Fredericksen, Todd; Fuentes, Alfredo; García-Villacorta, Roosevelt; Gonzales, Therany; Guevara Andino, Juan Ernesto; Honorio Coronado, Euridice N.; Huamantupa-Chuquimaco, Isau; Killeen, Timothy J.; Malhi, Yadvinder; Mendoza, Casimiro; Mogollón, Hugo; Jørgensen, Peter Møller; Montero, Juan Carlos; Mostacedo, Bonifacio; Nauray, William; Neill, David; Vargas, Percy Núñez; Palacios, Sonia; Palacios Cuenca, Walter; Pallqui Camacho, Nadir Carolina; Peacock, Julie; Phillips, Juan Fernando; Pickavance, Georgia; Quesada, Carlos Alberto; Ramírez-Angulo, Hirma; Restrepo, Zorayda; Reynel Rodriguez, Carlos; Paredes, Marcos Ríos; Sierra, Rodrigo; Silveira, Marcos; Stevenson, Pablo; Stropp, Juliana; Terborgh, John; Tirado, Milton; Toledo, Marisol; Torres-Lezama, Armando; Umaña, María Natalia; Urrego, Ligia Estela; Vasquez Martinez, Rodolfo; Gamarra, Luis Valenzuela; Vela, César I.A.; Vilanova Torre, Emilio; Vos, Vincent; Hildebrand, von Patricio; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R.; Zartman, Charles Eugene; Phillips, Oliver L.

    2017-01-01

    Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This implies

  2. Tree species composition, richness and diversity in the northern ...

    African Journals Online (AJOL)

    ... variability in tree species composition, richness, density and diversity across the northern forest-savanna ecotone of Ghana. The information could be crucial for monitoring and managing agro-ecosystems sustainability. A future study would be required to isolate proximate factors of tree species distribution in the ecotone.

  3. Efficient Bayesian Species Tree Inference under the Multispecies Coalescent.

    Science.gov (United States)

    Rannala, Bruce; Yang, Ziheng

    2017-09-01

    We develop a Bayesian method for inferring the species phylogeny under the multispecies coalescent (MSC) model. To improve the mixing properties of the Markov chain Monte Carlo (MCMC) algorithm that traverses the space of species trees, we implement two efficient MCMC proposals: the first is based on the Subtree Pruning and Regrafting (SPR) algorithm and the second is based on a node-slider algorithm. Like the Nearest-Neighbor Interchange (NNI) algorithm we implemented previously, both new algorithms propose changes to the species tree, while simultaneously altering the gene trees at multiple genetic loci to automatically avoid conflicts with the newly proposed species tree. The method integrates over gene trees, naturally taking account of the uncertainty of gene tree topology and branch lengths given the sequence data. A simulation study was performed to examine the statistical properties of the new method. The method was found to show excellent statistical performance, inferring the correct species tree with near certainty when 10 loci were included in the dataset. The prior on species trees has some impact, particularly for small numbers of loci. We analyzed several previously published datasets (both real and simulated) for rattlesnakes and Philippine shrews, in comparison with alternative methods. The results suggest that the Bayesian coalescent-based method is statistically more efficient than heuristic methods based on summary statistics, and that our implementation is computationally more efficient than alternative full-likelihood methods under the MSC. Parameter estimates for the rattlesnake data suggest drastically different evolutionary dynamics between the nuclear and mitochondrial loci, even though they support largely consistent species trees. We discuss the different challenges facing the marginal likelihood calculation and transmodel MCMC as alternative strategies for estimating posterior probabilities for species trees. [Bayes factor; Bayesian

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

    Science.gov (United States)

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

    2015-09-01

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

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

    Science.gov (United States)

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

    2012-01-01

    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). PMID:22422763

  6. Patterns of host adaptation in fly infecting Entomophthora species

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Jensen, Annette Bruun; Eilenberg, Jørgen

    .g. Entomophthora, Strongwellsea and Entomophaga). Species diversification of the obligate IPF within Entomophthoromycota thus seems to be primarily driven by co-evolutionary host adaptation to specific insect families, genera or species-complexes, but the underlying genetic factors of host adaptation...... in this fungal order are largely unknown and leave many unanswered questions. For example are the number of virulence factors increasing, or decreasing when fungal pathogens adapt to a narrow range of potential hosts? And, are host specialization based on many genetic changes with small effect or few with large...... differences and similarities in order to detect patterns of host-specific molecular adaptation....

  7. Defects in host immune function in tree frogs with chronic chytridiomycosis.

    Science.gov (United States)

    Young, Sam; Whitehorn, Paul; Berger, Lee; Skerratt, Lee F; Speare, Rick; Garland, Stephen; Webb, Rebecca

    2014-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused mass mortality leading to population declines and extinctions in many frog species worldwide. The lack of host resistance may be due to fungal immunosuppressive effects that have been observed when Bd is incubated with cultured lymphocytes, but whether in vivo host immunosuppression occurs is unknown. We used a broad range of hematologic and protein electrophoresis biomarkers, along with various functional tests, to assess immune competence in common green (Litoria caerulea) and white-lipped (L. infrafrenata) tree frogs experimentally infected with Bd. Compared with uninfected frogs, Bd infection in L. caerulea caused a reduction in immunoglobulin and splenic lymphocyte responses to antigenic stimulation with sheep red blood cells, along with decreased white blood cell and serum protein concentrations, indicating possible impaired immune response capability of Bd-infected frogs. This is the first in vivo study suggesting that infection with Bd causes multiple defects in systemic host immune function, and this may contribute to disease development in susceptible host species. Although L. infrafrenata failed to maintain Bd infection after exposure, white blood cell and serum globulin concentrations were lower in recovered frogs compared with unexposed frogs, but antigen-specific serum and splenic antibody, and splenic cellular, responses were similar in both recovered and unexposed frogs. This may indicate potential systemic costs associated with infection clearance and/or redirection of host resources towards more effective mechanisms to overcome infection. No clear mechanism for resistance was identified in L. infrafrenata, suggesting that localized and/or innate immune defense mechanisms may be important factors involved in disease resistance in this species.

  8. Defects in host immune function in tree frogs with chronic chytridiomycosis.

    Directory of Open Access Journals (Sweden)

    Sam Young

    Full Text Available The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd has caused mass mortality leading to population declines and extinctions in many frog species worldwide. The lack of host resistance may be due to fungal immunosuppressive effects that have been observed when Bd is incubated with cultured lymphocytes, but whether in vivo host immunosuppression occurs is unknown. We used a broad range of hematologic and protein electrophoresis biomarkers, along with various functional tests, to assess immune competence in common green (Litoria caerulea and white-lipped (L. infrafrenata tree frogs experimentally infected with Bd. Compared with uninfected frogs, Bd infection in L. caerulea caused a reduction in immunoglobulin and splenic lymphocyte responses to antigenic stimulation with sheep red blood cells, along with decreased white blood cell and serum protein concentrations, indicating possible impaired immune response capability of Bd-infected frogs. This is the first in vivo study suggesting that infection with Bd causes multiple defects in systemic host immune function, and this may contribute to disease development in susceptible host species. Although L. infrafrenata failed to maintain Bd infection after exposure, white blood cell and serum globulin concentrations were lower in recovered frogs compared with unexposed frogs, but antigen-specific serum and splenic antibody, and splenic cellular, responses were similar in both recovered and unexposed frogs. This may indicate potential systemic costs associated with infection clearance and/or redirection of host resources towards more effective mechanisms to overcome infection. No clear mechanism for resistance was identified in L. infrafrenata, suggesting that localized and/or innate immune defense mechanisms may be important factors involved in disease resistance in this species.

  9. The distribution of weaver ant pheromones on host trees

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2007-01-01

    for correlations between spot density, ant activity and the likelihood of being detected by an ant. Spots were only found on trees with ants. On ant-trees, spots were distributed throughout the trees but with higher densities in areas with high ant activity and pheromone densities were higher on twigs compared...

  10. Fish, fans and hydroids: host species of pygmy seahorses

    Directory of Open Access Journals (Sweden)

    Bastian Reijnen

    2011-06-01

    Full Text Available An overview of the octocoral and hydrozoa host species of pygmy seahorses is provided, based on recently collected data for H. bargibanti, H. denise and H. pontohi and literature records. Seven new interspecific host-species associations are recognized, and an overview of the so far documented number of host species is given. Detailed re-examination of octocoral type material and a review of the taxonomic history are included, as a baseline for further studies. The host-specificity and colour morphs of pygmy seahorses are discussed, as well as the validity of (previous identifications and conservations issues.

  11. Fish, fans and hydroids: host species of pygmy seahorses

    NARCIS (Netherlands)

    Reijnen, B.T.; Meij, van der S.E.T.; Ofwegen, van L.P.

    2011-01-01

    An overview of the octocoral and hydrozoan host species of pygmy seahorses is provided based on literature records and recently collected field data for Hippocampus bargibanti, H. denise and H. pontohi. Seven new associations are recognized and an overview of the so far documented host species is

  12. Intraspecific Variation in Armillaria Species from Shrubs and Trees in Northwestern Spain

    Directory of Open Access Journals (Sweden)

    O. Aguín

    2004-08-01

    Full Text Available Until recently, the identification of Armillaria species relied upon morphological characteristics and mating tests, but now molecular techniques based on polymorphisms in the IGS region of the fungal rDNA are more commonly used, since these are more rapid and reliable. Differences found in RFLP patterns identifying Armillaria species have suggested the existence of intraspecific variation. In this work, 185 Armillaria isolates from different plant species (including fruit trees, broadleaf and coniferous trees, ornamental shrubs, kiwifruit and grapevine affected by white root rot were analyzed by RFLP-PCR, in order to study intraspecific variation in Armillaria and the relationship with the plant host. Armillaria mellea was found in the majority of samples (71%, and was the most frequent Armillaria species in symptomatic ornamental shrubs, kiwifruit, grapevine, fruit trees and broadleaf trees. In conifers however white root rot was generally caused by Armillaria ostoyae. Armillaria gallica was identified, although with low incidence, in ornamental, coniferous, broadleaf and fruit hosts. Intraspecies variation was recorded only in A. mellea, for which RFLP patterns mel 1 and mel 2 were found. Most plants infected with A. mellea showed the mel 2 pattern. Further research is needed to study whether Armillaria RFLP patterns are specific to certain plant hosts, and whether intraspecific variation is related to differences in pathogenicity.

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

    Science.gov (United States)

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

    2011-05-12

    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.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  15. Spatial patterns of ectomycorrhizal assemblages in a monospecific forest in relation to host tree genotype

    Directory of Open Access Journals (Sweden)

    Christa eLang

    2013-04-01

    Full Text Available Ectomycorrhizas (EcM are important for soil exploration and thereby may shape belowground interactions of roots. We investigated the composition and spatial structures of EcM assemblages in relation to host genotype in an old-growth, monospecific beech (Fagus sylvatica forest. We hypothesized that neighboring roots of different beech individuals are colonized by similar EcM assemblages if host genotype had no influence on the fungal colonization and that the similarity would decrease with increasing distance of the sampling points. The alternative was that the EcM species showed preferences for distinct beech genotypes resulting in intraspecific variation of EcM-host assemblages. EcM species identities, abundance and exploration type as well as the genotypes of the colonized roots were determined in each sampling unit of a 1 L soil core (r = 0.04m, depth 0.2m. The Morisita-Horn similarity indices (MHSI based on EcM species abundance and multiple community comparisons were calculated. No pronounced variation of MHSI with increasing distances of the sampling points within a plot was found, but variations between plots. Very high similarities and no between-plot variation were found for MHSI based on EcM exploration types suggesting homogenous soil foraging in this ecosystem. The EcM community on different root genotypes in the same soil core exhibited high similarity, whereas the EcM communities on the root of the same tree genotype in different soil cores were significantly dissimilar. This finding suggests that spatial structuring of EcM assemblages occurs within the root system of an individual. This may constitute a novel, yet unknown mechanism ensuring colonization by a diverse EcM community of the roots of a given host individual.

  16. Status of Indigenous Tree Species in Girei Forest Reserve of ...

    African Journals Online (AJOL)

    ... sampled plot (p > 0.05). At this point of endangerment of the indigenous tree species, there is therefore a need for conservation strategies for future use of these indigenous trees and to reduce the effect of global warming on the earth surface. Keywords: Quantitative assessment, Global warming, Indigenous, Conservation, ...

  17. Composition and distribution of economic tree species in Nagi ...

    African Journals Online (AJOL)

    The inventory of economic trees in Nagi Natural Forest Reserve, Benue state was carried out to determine the status and dominance tree species. A total area of 0.4ha was sampled representing twenty percent of the reserve. Ten (10) sample plots of equal size (20 m x 20m) were randomly selected using simple random ...

  18. Directional Selection from Host Plants Is a Major Force Driving Host Specificity in Magnaporthe Species.

    Science.gov (United States)

    Zhong, Zhenhui; Norvienyeku, Justice; Chen, Meilian; Bao, Jiandong; Lin, Lianyu; Chen, Liqiong; Lin, Yahong; Wu, Xiaoxian; Cai, Zena; Zhang, Qi; Lin, Xiaoye; Hong, Yonghe; Huang, Jun; Xu, Linghong; Zhang, Honghong; Chen, Long; Tang, Wei; Zheng, Huakun; Chen, Xiaofeng; Wang, Yanli; Lian, Bi; Zhang, Liangsheng; Tang, Haibao; Lu, Guodong; Ebbole, Daniel J; Wang, Baohua; Wang, Zonghua

    2016-05-06

    One major threat to global food security that requires immediate attention, is the increasing incidence of host shift and host expansion in growing number of pathogenic fungi and emergence of new pathogens. The threat is more alarming because, yield quality and quantity improvement efforts are encouraging the cultivation of uniform plants with low genetic diversity that are increasingly susceptible to emerging pathogens. However, the influence of host genome differentiation on pathogen genome differentiation and its contribution to emergence and adaptability is still obscure. Here, we compared genome sequence of 6 isolates of Magnaporthe species obtained from three different host plants. We demonstrated the evolutionary relationship between Magnaporthe species and the influence of host differentiation on pathogens. Phylogenetic analysis showed that evolution of pathogen directly corresponds with host divergence, suggesting that host-pathogen interaction has led to co-evolution. Furthermore, we identified an asymmetric selection pressure on Magnaporthe species. Oryza sativa-infecting isolates showed higher directional selection from host and subsequently tends to lower the genetic diversity in its genome. We concluded that, frequent gene loss or gain, new transposon acquisition and sequence divergence are host adaptability mechanisms for Magnaporthe species, and this coevolution processes is greatly driven by directional selection from host plants.

  19. Determination of horizontal and vertical distribution of tree species in ...

    African Journals Online (AJOL)

    Determination of horizontal and vertical distribution of tree species in Turkey via Shuttle Radar Topography Mission (SRTM) satellite data and geographic information system: the case of Crimean pine ( Pinus nigra )

  20. The role of exotic tree species in Nordic forestry

    DEFF Research Database (Denmark)

    Kjær, Erik Dahl; Lobo, Albin; Myking, Tor

    2014-01-01

    The selection of suitable tree species is a prerequisite for successful forestry, and the use of exotic species as an alternative to native species is often a relevant option. In this paper, we discuss this option in relation to the present and future wood production in Nordic forestry. We revisi...

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

    Science.gov (United States)

    Lückmann, Katrin; Menzel, Susanne

    2014-01-01

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

  2. On the Number of Non-equivalent Ancestral Configurations for Matching Gene Trees and Species Trees.

    Science.gov (United States)

    Disanto, Filippo; Rosenberg, Noah A

    2017-09-14

    An ancestral configuration is one of the combinatorially distinct sets of gene lineages that, for a given gene tree, can reach a given node of a specified species tree. Ancestral configurations have appeared in recursive algebraic computations of the conditional probability that a gene tree topology is produced under the multispecies coalescent model for a given species tree. For matching gene trees and species trees, we study the number of ancestral configurations, considered up to an equivalence relation introduced by Wu (Evolution 66:763-775, 2012) to reduce the complexity of the recursive probability computation. We examine the largest number of non-equivalent ancestral configurations possible for a given tree size n. Whereas the smallest number of non-equivalent ancestral configurations increases polynomially with n, we show that the largest number increases with [Formula: see text], where k is a constant that satisfies [Formula: see text]. Under a uniform distribution on the set of binary labeled trees with a given size n, the mean number of non-equivalent ancestral configurations grows exponentially with n. The results refine an earlier analysis of the number of ancestral configurations considered without applying the equivalence relation, showing that use of the equivalence relation does not alter the exponential nature of the increase with tree size.

  3. Mapping urban forest tree species using IKONOS imagery: preliminary results.

    Science.gov (United States)

    Pu, Ruiliang

    2011-01-01

    A stepwise masking system with high-resolution IKONOS imagery was developed to identify and map urban forest tree species/groups 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). The system was implemented with soil-adjusted vegetation index (SAVI) threshold, textural information after running a low-pass filter, and brightness threshold of NIR band to separate tree canopies from non-vegetated areas from other vegetation types (e.g., grass/lawn) and to separate the tree canopies into sunlit and shadow areas. A maximum likelihood classifier was used to identify and map forest type and species. After IKONOS imagery was preprocessed, a total of nine spectral features were generated, including four spectral bands, three hue-intensity-saturation indices, one SAVI, and one texture image. The identified and mapped results were examined with independent ground survey data. The experimental results indicate that when classifying all the eight tree species/ groups with the high-resolution IKONOS image data, the identifying accuracy was very low and could not satisfy a practical application level, and when merging the eight species/groups into four major species/groups, the average accuracy is still low (average accuracy = 73%, overall accuracy = 86%, and κ = 0.76 with sunlit test samples). Such a low accuracy of identifying and mapping the urban tree species/groups is attributable to low spatial resolution IKONOS image data relative to tree crown size, to complex and variable background spectrum impact on crown spectra, and to shadow/shaded impact. The preliminary results imply that to improve the tree species identification accuracy and achieve a practical application level in urban area, multi-temporal (multi

  4. Evaluation of weeds as possible hosts of the potyviruses associated with tree tomato (Solanum betaceum Cav. viroses

    Directory of Open Access Journals (Sweden)

    Sierra S. Adela

    2012-04-01

    Full Text Available

    To determine possible weed hosts of potyviruses associated with the disease known as “tree tomato virus disease” in Antioquia department (Colombia, a sampling was conducted to identify weed species commonly found in commercial crops of S. betaceum affected by the virus and the possible presence of the virus in these plants. The encountered weed species were grouped into seven different taxonomic families, within which we evaluated the ten most common species. The selected weeds, three indicator species of the virus and tree tomato plants were grown in a greenhouse and mechanically inoculated with an extract of infected tree tomato tissue. One month after inoculation, the tree tomato plants and Nicotiana tabacum showed symptoms of the disease and were serologically positive, whereas none of the weeds showed symptoms or were positive for potyviruses serology. In order to confirm that the detection of the virus was not caused by low viral titers that did not reach the minimum detection level of the test used, the tomato tree plants were reinoculated with an extract of sap from the studied weeds and potyviruses was not detected in any of the tested weeds and therefore cannot be considered, with the utilized methodology, as hosts for the potyviruses affecting tree tomato plants.

  5. Genetic improvement of forest tree species

    Directory of Open Access Journals (Sweden)

    Teotônio Francisco Assis

    2011-01-01

    Full Text Available Brazilian forestry sector is considered one of the most developed in the world, being the base for important industrialsegments which use wood as raw material. Tree breeding has played an important role on improving the competitiveness ofBrazilian forestry-based companies, especially for its positive reflexes on increasing adaptation, forestry productivity and woodquality. In spite of the importance of other forest trees for the economy, such as Schizolobium, Araucaria, Populus and Hevea, themain genera under genetic improvement in the country are Eucalyptus, Pinus, Acacia and Tectona. They are used by industries likepulp and paper, siderurgy, tannin, chips for exportation and lumber, constituting an important source of revenues for the Brazilian’seconomy, besides their positive social and environmental impacts. This paper presents a generic approach to genetic improvementaspects of these four major genera currently undergoing breeding in Brazil.

  6. Tree-oriented silviculture for growing valuable broadleaved tree species in Turkey oak coppices

    Directory of Open Access Journals (Sweden)

    Diego Giuliarelli

    2016-11-01

    Full Text Available Valuable broadleaved tree species can play an important role in mixed-forest management; in these forests, silviculture may play an important role in getting high value timber. This paper illustrates a tree-oriented silviculture approach with an application in a Turkey oak coppice stand in Central Italy. This silvicultural approach has been developed in the last decades in France, Germany, Switzerland. The rationale behind the tree-oriented approach is to select a number of target sporadic tree species with valuable timber and to support their growth through repeated thinning from above. We tested the effectiveness of this silviculture approach as an alternative to customary coppice management in Italy, which is traditionally focused on the dominant tree species and does not consider valuable broadleaved tree species. The two silviculture approaches (tree-oriented and customary coppicing were compared through a financial evaluation of the economic convenience of the two alternatives in a Turkey oak coppice stand in Central Italy

  7. Soil nutrients influence spatial distributions of tropical tree species.

    Science.gov (United States)

    John, Robert; Dalling, James W; Harms, Kyle E; Yavitt, Joseph B; Stallard, Robert F; Mirabello, Matthew; Hubbell, Stephen P; Valencia, Renato; Navarrete, Hugo; Vallejo, Martha; Foster, Robin B

    2007-01-16

    The importance of niche vs. neutral assembly mechanisms in structuring tropical tree communities remains an important unsettled question in community ecology [Bell G (2005) Ecology 86:1757-1770]. There is ample evidence that species distributions are determined by soils and habitat factors at landscape (Yasuni), and Panama (Barro Colorado Island). Using spatial distribution maps of >0.5 million individual trees of 1,400 species and 10 essential plant nutrients, we used Monte Carlo simulations of species distributions to test plant-soil associations against null expectations based on dispersal assembly. We found that the spatial distributions of 36-51% of tree species at these sites show strong associations to soil nutrient distributions. Neutral dispersal assembly cannot account for these plant-soil associations or the observed niche breadths of these species. These results indicate that belowground resource availability plays an important role in the assembly of tropical tree communities at local scales and provide the basis for future investigations on the mechanisms of resource competition among tropical tree species.

  8. tree structural and species diversities in okwangwo forest, cross river

    African Journals Online (AJOL)

    Tersor

    tree species, which form the frame for other life forms. The Okwangwo forest is an area generally believed to be rich in plant and animal species, not present in other ...... Distribution and Abundance of Selected. Non-timber Forest Products in the. Takamanda National Park, Cameroon. International Journal of Biodiversity.

  9. tree structural and species diversities in okwangwo forest, cross river

    African Journals Online (AJOL)

    Tersor

    ABSTRACT. For sound forest management decisions, appraisal of flora species and forest structure is crucial for any meaningful .... the study area. TREE STRUCTURAL AND SPECIES DIVERSITIES IN OKWANGWO FOREST, CROSS RIVER STATE, NIGERIA ..... architecture to absorb nutrients for growth. This is in line with ...

  10. ( Dialium guineense willd), a multipurpose tree species

    African Journals Online (AJOL)

    The velvet tamarind (Dialium guineense Willd) is one of the key species for domestication in Sub-Saharan Africa. In order to help the sustainable management and conservation of this species, its structural characteristics and ethnobotanical traits were studied in the 4 vegetation types (typical dense forest, degraded dense ...

  11. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Invasive plants are species that can grow and spread aggressively, mature quickly, and invade an ecosystem causing economic and environmental damage. Invasive plants usually invade disturbed areas, but can also colonize small areas quickly, and may spread and dominate large areas in a few short years. Invasive plant species displace native or desirable forest...

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

    Directory of Open Access Journals (Sweden)

    Haibao Ren

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

  13. Host Life History Strategy, Species Diversity, and Habitat Influence Trypanosoma cruzi Vector Infection in Changing Landscapes

    Science.gov (United States)

    Gottdenker, Nicole L.; Chaves, Luis Fernando; Calzada, José E.; Saldaña, Azael; Carroll, C. Ronald

    2012-01-01

    Background Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. Methodology/Principal Findings R. pallescens vectors (N = 643) were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3%) vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3%) dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas) were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as rmax, the maximum intrinsic rate of population increase), and habitat type (forest fragments and peridomiciliary sites) were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of rmax were positively associated with higher vector infection rate at a site. Conclusions/Significance In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially

  14. Host life history strategy, species diversity, and habitat influence Trypanosoma cruzi vector infection in Changing landscapes.

    Directory of Open Access Journals (Sweden)

    Nicole L Gottdenker

    Full Text Available Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama.R. pallescens vectors (N = 643 were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3% vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3% dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as r(max, the maximum intrinsic rate of population increase, and habitat type (forest fragments and peridomiciliary sites were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of r(max were positively associated with higher vector infection rate at a site.In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially by changing host community structure to favor hosts

  15. Species richness and resource availability: A phylogenetic analysis of insects associated with trees

    OpenAIRE

    Kelly, C. K.; Southwood, T. R. E.

    1999-01-01

    The data on the number of species of insects associated with various trees in Britain have been reanalyzed to factor out possible bias from phylogenetic effects. It was found that tree availability (range and abundance) continues to provide a good predictor (r = 0.852) of insect-species richness, slightly better than straightforward cross-species analyses. Of the two components of tree availability, tree abundance gives a much better prediction than tree range. The species richness on trees o...

  16. Colletotrichum species with curved conidia from herbaceous hosts

    NARCIS (Netherlands)

    Damm, U.; Woudenberg, J.H.C.; Cannon, P.F.; Crous, P.W.

    2009-01-01

    Colletotrichum (Glomerellaceae, Sordariomycetes) species with dark setae and curved conidia are known as anthracnose pathogens of a number of economically important hosts and are often identified as C. dematium. Colletotrichum dematium has been synonymised with many species, including the type of

  17. Germplasm characterization of three jabuticaba tree species

    Directory of Open Access Journals (Sweden)

    Moeses Andrigo Danner

    2011-09-01

    Full Text Available The purpose of this study was to characterize cultivated genotypes of three jabuticaba species (Plinia cauliflora, P. trunciflora, and P. jaboticaba. Phenology and fruit growth, as well as leaf, flower and fruit traits were evaluated. Variability in all traits was observed among genotypes of the three jabuticaba species. The trait peduncle size is indicated for differentiation of the three species under study. The leaf and fruit sizes of the genotypes P. trunciflora 3, P. trunciflora 4, P. trunciflora 5 and P. jaboticaba 1 differ from those described in the literature for these species, indicating the formation of ecotypes. Jabuticaba fruit skin contains high anthocyanin and flavonoid concentrations, with potential use in food and pharmaceutical industries.

  18. Are cryptic host species also cryptic to parasites? Host specificity and geographical distribution of acanthocephalan parasites infecting freshwater Gammarus

    OpenAIRE

    Westram A. M.; Baumgartner C; Keller I; Jokela J.

    2011-01-01

    Many parasites infect multiple host species. In coevolving host parasite interactions theory predicts that parasites should be adapted to locally common hosts which could lead to regional shifts in host preferences. We studied the interaction between freshwater Gammarus (Crustacea Amphipoda) and their acanthocephalan parasites using a large scale field survey and experiments combined with molecular identification of cryptic host and parasite species. Gammarus pulex is a common host for multip...

  19. Genera of diaporthalean coelomycetes associated with leaf spots of tree hosts.

    Science.gov (United States)

    Crous, P W; Summerell, B A; Alfenas, A C; Edwards, J; Pascoe, I G; Porter, I J; Groenewald, J Z

    2012-06-01

    Four different genera of diaporthalean coelomycetous fungi associated with leaf spots of tree hosts are morphologically treated and phylogenetically compared based on the DNA sequence data of the large subunit nuclear ribosomal DNA gene (LSU) and the internal transcribed spacers and 5.8S rRNA gene of the nrDNA operon. These include two new Australian genera, namely Auratiopycnidiella, proposed for a leaf spotting fungus occurring on Tristaniopsis laurina in New South Wales, and Disculoides, proposed for two species occurring on leaf spots of Eucalyptus leaves in Victoria. Two new species are described in Aurantiosacculus, a hitherto monotypic genus associated with leaf spots of Eucalyptus in Australia, namely A. acutatus on E. viminalis, and A. eucalyptorum on E. globulus, both occurring in Tasmania. Lastly, an epitype specimen is designated for Erythrogloeum hymenaeae, the type species of the genus Erythrogloeum, and causal agent of a prominent leaf spot disease on Hymenaea courbaril in South America. All four genera are shown to be allied to Diaporthales, although only Aurantiosacculus (Cryphonectriaceae) could be resolved to family level, the rest being incertae sedis.

  20. Effects of tree species composition on within-forest distribution of understorey species

    NARCIS (Netherlands)

    Oijen, van D.; Feijen, M.; Hommel, P.W.F.M.; Ouden, den J.; Waal, de R.W.

    2005-01-01

    Question: Do tree species, with different litter qualities, affect the within-forest distribution of forest understorey species on intermediate to base-rich soils? Since habitat loss and fragmentation have caused ancient forest species to decline, those species are the main focus of this study.

  1. Differential Host Plant-Associated Genetic Variation Between Sympatric Mite Species of the Genus Oligonychus (Acari: Tetranychidae).

    Science.gov (United States)

    Guzman-Valencia, Stephanie; Santillán-Galicia, Ma Teresa; Guzmán-Franco, Ariel W; Vega-Muñoz, Ricardo

    2017-04-01

    Adaptation to different host plants can lead to host-associated differentiation (HAD). The mites Oligonychus perseae and Oligonychus punicae have a broad range of host plants, but, to date, records of them coexisting sympatrically had only been reported on avocado. However, our field observations showed both species coexisting on host plants other than avocado. The lack of previous records of these mites on the host plants studied here suggests only recent divergence to new host plant species. Previous studies showed that O. punicae had a limited migration capacity compared with O. perseae, suggesting that O. punicae is more likely to develop a close host plant relationship leading to HAD. Adults of both species were collected from trees hosting both mite species. Three genera of host plants considered were Persea, Salix, and Alnus; two species within one genus were Alnus jorullensis and Alnus acuminata; and three varieties within one species were Persea americana var. Fuerte, var. Hass, and var. Criollo, a noncommercial variety. Using sequence data from a segment of the mitochondrial cytochrome oxidase subunit I, the phylogenetic relationships and genetic population structure of both mite species in relation to the host plant were determined. Oligonychus perseae populations showed a significant population structure in relation to host plant at the species and genus level, but there was no effect of variety. In contrast, host plant explained none of the genetic variation among O. punicae populations. The potential role of coexistence mechanisms in the contrasting genetic population structure of both mite species is discussed. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest.

    Science.gov (United States)

    Victoriano-Romero, Elizabeth; Valencia-Díaz, Susana; Toledo-Hernández, Víctor Hugo; Flores-Palacios, Alejandro

    2017-01-01

    Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera) and low (Conzattia multiflora) epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4-5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds.

  3. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest

    Science.gov (United States)

    2017-01-01

    Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera) and low (Conzattia multiflora) epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4–5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds. PMID:28158320

  4. EFFECTS OF TREE SPECIES, TREE CROWN TYPE AND SEASONS ON SOIL ACIDITY

    Directory of Open Access Journals (Sweden)

    Temel Sarıyıldız

    2004-11-01

    Full Text Available The aim of the present study was to determine the effects of tree species, crown type, seasons and distance from the stem on soil pH. The soil samples (depth of 0-15 and >15 cm were collected from under pine (Pinus sylvestris L., spruce (Picea orientalis L. and alder (Alnus glutinosa L. trees in November 2002, March and June 2003 at distance of 30, 90, 180 and 270 cm from the stem. Highest pH was found under alder trees, whereas lowest pH was found under pine trees. There was a decrease in soil pH from Autumn to Summer for all species. In Autumn and Spring, pine and spruce showed an increase in soil pH from the stem to the distance of 180 cm. After that they showed a decrease, whereas in Summer, they didn’t show any changes with the distances. Alder, however, didn’t show any significant changes between the distances in any season. It was found that the differences in soil pH between species, seasons and the distances from the stem were significantly affected by the changes in pH of organic layer. In conclusion, the results in the present study indicate that tree species, seasons and the distance from the stem are all important factors influencing soil pH, and should be considered together in future studies.

  5. Multilocus inference of species trees and DNA barcoding.

    Science.gov (United States)

    Mallo, Diego; Posada, David

    2016-09-05

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

  6. Regional assessment of ozone sensitive tree species using bioindicator plants.

    Science.gov (United States)

    Coulston, John W; Smith, Gretchen C; Smith, William D

    2003-04-01

    Tropospheric ozone occurs at phytotoxic levels in the northeastern and mid-Atlantic regions of the United States. Quantifying possible regional-scale impacts of ambient ozone on forest tree species is difficult and is confounded by other factors, such as moisture and light, which influence the uptake of ozone by plants. Biomonitoring provides an approach to document direct foliar injury irrespective of direct measure of ozone uptake. We used bioindicator and field plot data from the USDA Forest Service to identify tree species likely to exhibit regional-scale ozone impacts. Approximately 24% of sampled sweetgum (Liquidambar styraciflua), 15% of sampled loblolly pine (Pinus taeda), and 12% of sampled black cherry (Prunus serotina) trees were in the highest risk category. Sweetgum and loblolly pine trees were at risk on the coastal plain of Maryland, Virginia and Delaware. Black cherry trees were at risk on the Allegheny Plateau (Pennsylvania), in the Allegheny Mountains (Pennsylvania, West Virginia, and Maryland) as well as coastal plain areas of Maryland and Virginia. Our findings indicate a need for more in-depth study of actual impacts on growth and reproduction of these three species.

  7. Nitrogen addition enhances drought sensitivity of young deciduous tree species

    Directory of Open Access Journals (Sweden)

    Christoph Dziedek

    2016-07-01

    Full Text Available Understanding how trees respond to global change drivers is central to predict changes in forest structure and functions. Although there is evidence on the mode of nitrogen (N and drought (D effects on tree growth, our understanding of the interplay of these factors is still limited. Simultaneously, as mixtures are expected to be less sensitive to global change as compared to monocultures, we aimed to investigate the combined effects of N addition and D on the productivity of three tree species (Fagus sylvatica, Quercus petraea, Pseudotsuga menziesii in relation to functional diverse species mixtures using data from a four-year field experiment in Northwest Germany. Here we show that species mixing can mitigate the negative effects of combined N fertilization and D events, but the community response is mainly driven by the combination of certain traits rather than the tree species richness of a community. For beech, we found that negative effects of D on growth rates were amplified by N fertilization (i.e. combined treatment effects were non-additive, while for oak and fir, the simultaneous effects of N and D were additive. Beech and oak were identified as most sensitive to combined N+D effects with a strong size-dependency observed for beech, suggesting that the negative impact of N+D becomes stronger with time as beech grows larger. As a consequence, the net biodiversity effect declined at the community level, which can be mainly assigned to a distinct loss of complementarity in beech-oak mixtures. This pattern, however, was not evident in the other species-mixtures, indicating that neighborhood composition (i.e. trait combination, but not tree species richness mediated the relationship between tree diversity and treatment effects on tree growth. Our findings point to the importance of the qualitative role (‘trait portfolio’ that biodiversity play in determining resistance of diverse tree communities to environmental changes. As such, they

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

    Science.gov (United States)

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

    2016-01-01

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

  9. tropiTree: an NGS-based EST-SSR resource for 24 tropical tree species.

    Directory of Open Access Journals (Sweden)

    Joanne R Russell

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

  10. tropiTree: an NGS-based EST-SSR resource for 24 tropical tree species.

    Science.gov (United States)

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

    2014-01-01

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

  11. Species of Mycosphaerellaceae and Teratosphaeriaceae on native Myrtaceae in Uruguay: evidence of fungal host jumps.

    Science.gov (United States)

    Pérez, C A; Wingfield, M J; Altier, N; Blanchette, R A

    2013-02-01

    Mycosphaerella species are well-known causal agents of leaf diseases on many economically and ecologically important plant species. In Uruguay, a relatively large number of Mycosphaerellaceae and Teratosphaeriaceae are found on Eucalyptus, but nothing is known of these fungi on native Myrtaceae. The aim of this study was to identify Mycosphaerellaceae and Teratosphaeriaceae species associated with leaf diseases on native Myrtaceae in Uruguay and to consider whether host jumps by the pathogen from introduced Eucalyptus to native Myrtaceae have occurred. Several native forests throughout the country were surveyed with special attention given to those located close to Eucalyptus plantations. Five species belonging to the Mycosphaerellaceae and Teratosphaeriaceae clades were found on native Myrtaceous trees and three of these had previously been reported on Eucalyptus in Uruguay. Those occurring both on Eucalyptus and native Myrtaceae included Pallidocercospora heimii, Pseudocercospora norchiensis, and Teratosphaeria aurantia. In addition, Mycosphaerella yunnanensis, a species known to occur on Eucalyptus but not previously recorded in Uruguay, was found on leaves of two native Myrtaceous hosts. Because most of these species occur on Eucalyptus in countries other than Uruguay, it appears that they were introduced in this country and have adapted to be able to infect native Myrtaceae. These apparent host jumps have the potential to result in serious disease problems and they should be carefully monitored. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  12. Stem biomass and volume models of selected tropical tree species ...

    African Journals Online (AJOL)

    (Bombacaceae), Dialium guineense Willd. (Caesalpiniaceae), Diospyros mespiliformis Hochst. ex A.DC. (Ebenaceae) in natural protected tropical forests and, in addition, Tectona grandis L.f. (Verbenaceae) in plantations. In addition to the tree species specific equations, basic wood density, as well as carbon, nitrogen, ...

  13. Performance of Asian longhorned beetle among tree species

    Science.gov (United States)

    Kelli Hoover; Scott Ludwig; James Sellmer; Deborah McCullough; Laura Lazarus

    2003-01-01

    Two procedures were evaluated for assessing susceptibility of a variety of tree species to Anoplophora glabripennis. In the first procedure, adult beetles were caged with a section of sugar maple, northern red oak, white oak, honeylocust, eastern cottonwood, sycamore or tulip poplar wood and allowed to oviposit.

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

    African Journals Online (AJOL)

    It is well established that trees help to reduce air pollution, and there is a growing impetus for green belt expansion in urban areas. For greenbelt development, it is necessary to select plants that tolerant air pollution. In this study, the air pollution tolerance index (APTI) of plant species was evaluated by analyzing some ...

  15. Updated generalized biomass equations for North American tree species

    Science.gov (United States)

    David C. Chojnacky; Linda S. Heath; Jennifer C. Jenkins

    2014-01-01

    Historically, tree biomass at large scales has been estimated by applying dimensional analysis techniques and field measurements such as diameter at breast height (dbh) in allometric regression equations. Equations often have been developed using differing methods and applied only to certain species or isolated areas. We previously had compiled and combined (in meta-...

  16. Anatomical studies of selected tree species of the Moraceae family ...

    African Journals Online (AJOL)

    The internode, bark and wood anatomy of seven tree species of the Family Moraceae, grown in Nigeria were studied to determine their characteristic tissue distribution and unique ergastic substances which could be of immense value in taxonomic work as well as of great economic and medicinal values. Direct microscopic ...

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

    African Journals Online (AJOL)

    Administrator

    2011-05-05

    May 5, 2011 ... Mycorrhizal colonization of different agroforestry tree species in two social forestry nurseries was investigated. Percentage of Arbuscular ... collected from two social forestry nurseries of Mahabubnagar district (A.P), and brought to the .... main regression line is shown in red. Spores of the lower infection ...

  18. Tolerance of Four Tropical Tree Species to Heavy Petroleum Contamination

    NARCIS (Netherlands)

    Perez-Hernandez, I.; Ochoa-Gaona, S.; Schroeder, R.H.A.; Rivera-Cruz, M.C.; Geissen, V.

    2013-01-01

    Four species of trees were selected to evaluate the tolerance to heavy crude oil contamination by means of a tolerance index integrating germination, height, biomass and survival as variables. Fresh seeds to Cedrela odorata (tropical cedar), Haematoxylum campechianum (tinto bush), Swietenia

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-01

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

  20. Tree species composition, structure and utilisation in Maruzi Hills ...

    African Journals Online (AJOL)

    The study investigated the tree species composition, vegetation structure and harvesting pattern to guide management of the Maruzi Hills Forest Reserve. Stratified random sampling was used to site six (100 m × 100 m) permanent sample plots in the woodland, bushland and grassland vegetation types identified in the ...

  1. Performance of some multipurpose tree species: the Forestry ...

    African Journals Online (AJOL)

    The mortality of the tree species on-farm was variable, ranging from 39 to 64% in 1991 and 2 to 54% in 1996. Leucaena leucocephala, A. holosericea, Melia azedarach and Senna atomaria had the greatest growth and biomass production. Farmers preferred L. leucocephala and Casuarina cunninghamiana, which was ...

  2. Biomass equations for major tree species of the Northeast

    Science.gov (United States)

    Louise M. Tritton; James W. Hornbeck

    1982-01-01

    Regression equations are used in both forestry and ecosystem studies to estimate tree biomass from field measurements of dbh (diameter at breast height) or a combination of dbh and height. Literature on biomass is reviewed, and 178 sets of publish equation for 25 species common to the Northeastern Unites States are listed. On the basis of these equations, estimates of...

  3. Evaluation of three indigenous Multi-purpose tree species for ...

    African Journals Online (AJOL)

    Agronomic evaluation of three indigenous Multi-purpose tree species (MPTS) namely Pterocarpus santalinoides (PS), Grewia pubescens (GP) and Enterolobium cyclocarpum (EC) and one exotic Leucaena leucocephala (LL) which acted as the control were investigated to determine their growth performance and biomass ...

  4. Determination of horizontal and vertical distribution of tree species in ...

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... using a digital elevation model obtained from Shuttle Radar Topography Mission (SRTM) satellite data and 1/100,000 scale Forest Information System database, horizontal and vertical distribution of Pinus nigra (Crimean Pine), which is geographically the largest spread needled tree species in Turkey, (to.

  5. Distribution Characteristics of Mineral Elements in Tree Species ...

    African Journals Online (AJOL)

    Fiifi Baidoo

    The other families comprised Papilionaceae, Apocynaceae, Sterculiaceae, Connaraceae,. Sapindaceae, Laurraceae, Combretaceae, Bombaceae, Bignoniaceae, Ulmaceae, Annonaceae and. Anacardiaceae, and constituted 34.4% (Fig. 1b). A total of 18 different tree species families were identified in AS and 16 in DS ...

  6. Bat fly species richness in Neotropical bats: correlations with host ecology and host brain.

    Science.gov (United States)

    Bordes, Frédéric; Morand, Serge; Ricardo, Guerrero

    2008-11-01

    Patterns of ectoparasite species richness in mammals have been investigated in various terrestrial mammalian taxa such as primates, ungulates and carnivores. Several ecological or life traits of hosts are expected to explain much of the variability in species richness of parasites. In the present comparative analysis we investigate some determinants of parasite richness in bats, a large and understudied group of flying mammals, and their obligate blood-sucking ectoparasite, streblid bat flies (Diptera). We investigate the effects of host body size, geographical range, group size and roosting ecology on the species richness of bat flies in tropical areas of Venezuela and Peru, where both host and parasite diversities are high. We use the data from a major sampling effort on 138 bat species from nine families. We also investigate potential correlation between bat fly species richness and brain size (corrected for body size) in these tropical bats. We expect a relationship if there is a potential energetic trade-off between costly large brains and parasite-mediated impacts. We show that body size and roosting in cavities are positively correlated with bat fly species richness. No effects of bat range size and group size were observed. Our results also suggest an association between body mass-independent brain size and bat fly species richness.

  7. Host preference and species richness of wood-inhabiting aphyllophoraceous fungi in a cool temperate area of Japan.

    Science.gov (United States)

    Yamashita, Satoshi; Hattori, Tsutomu; Abe, Hisashi

    2010-01-01

    We examined the species richness and host utilization patterns of wood-inhabiting aphyllophoraceous fungi (polypores and related fungi) in an old-growth beech and oak forest in a cool, temperate area of Japan. Coarse woody debris (CWD) > or = 20 cm diam within a 6 ha plot was surveyed in Sep 2002. Tree genus, diameter, decay class and tree part of CWD samples were recorded. Fruiting bodies of aphyllophoraceous fungi that arose from the CWD were surveyed three times and identified to species. In total 256 CWD samples from 12 tree genera were surveyed with Quercus being the most frequent followed by Castanea and Fagus. From 196 CWD samples we recorded 436 wood-inhabiting fungi belonging to 63 species. Fifteen fungal species had at least 10 records, with Hymenochaete rubiginosa, Daedalea dickinsii, Xylobolus frustulatus, Rigidoporus cinereus and the small form of Fomes fomentarius being the most frequent. The number of fungal species that appeared on Fagus was significantly larger than that on Castanea, when the number of fruiting bodies collected was at least 50. The occurrences of the 15 dominant fungal species, except Trametes versicolor, were related to traits of the CWD. Tree genus was a predictor variable that affected the appearance of 11 of the 15 species of wood-inhabiting fungi. Only the tree part was selected for the models of Rigidoporus eminens, Schizopora flavipora and Stereum ostrea. Our results suggest that tree genus and tree part are important factors determining fungal community structure because these were selected as complementary predictor variables. Both oak and beech appear to be the most important tree genera for maintaining wood-inhabiting fungal species richness because the fungal flora formed on oak CWD is nearly complementary to those on chestnut, with low fungal species richness.

  8. Tree species effects on pathogen-suppressive capacities of soil bacteria across two tropical dry forests in Costa Rica.

    Science.gov (United States)

    Becklund, Kristen; Powers, Jennifer; Kinkel, Linda

    2016-11-01

    Antibiotic-producing bacteria in the genus Streptomyces can inhibit soil-borne plant pathogens, and have the potential to mediate the impacts of disease on plant communities. Little is known about how antibiotic production varies among soil communities in tropical forests, despite a long history of interest in the role of soil-borne pathogens in these ecosystems. Our objective was to determine how tree species and soils influence variation in antibiotic-mediated pathogen suppression among Streptomyces communities in two tropical dry forest sites (Santa Rosa and Palo Verde). We targeted tree species that co-occur in both sites and used a culture-based functional assay to quantify pathogen-suppressive capacities of Streptomyces communities beneath 50 focal trees. We also measured host-associated litter and soil element concentrations as potential mechanisms by which trees may influence soil microbes. Pathogen-suppressive capacities of Streptomyces communities varied within and among tree species, and inhibitory phenotypes were significantly related to soil and litter element concentrations. Average proportions of inhibitory Streptomyces in soils from the same tree species varied between 1.6 and 3.3-fold between sites. Densities and proportions of pathogen-suppressive bacteria were always higher in Santa Rosa than Palo Verde. Our results suggest that spatial heterogeneity in the potential for antibiotic-mediated disease suppression is shaped by tree species, site, and soil characteristics, which could have significant implications for understanding plant community composition and diversity in tropical dry forests.

  9. Biomass Equations for Tropical Forest Tree Species in Mozambique

    Directory of Open Access Journals (Sweden)

    Rosta Mate

    2014-03-01

    Full Text Available Chanfuta (Afzelia quanzensis Welw., Jambire (Millettia stuhlmannii Taub. and Umbila (Pterocarpus angolensis D.C. are, among others, three of the main tropical tree species producing commercial timber in Mozambique. The present study employed destructive biomass estimation methods at three localities in Mozambique (Inhaminga, Mavume, and Tome to acquire data on the mean diameter at breast height (DBH, and height of trees sampled in 21 stands each of Chanfuta and Jambire, and 15 stands of Umbila. Mean diameter at breast height (DBH (ob for Chanfuta, Jambire, and Umbila was: 33.8 ± 12.6 (range 13.5–61.1, 33.4 ± 7.4 (range 21.0–52.2, and 27.0 ± 9.5 (range 14.0–46.5 cm. The mean total values for biomass (kg of trees of Chanfuta, Jambire, and Umbila trees were 864, 1016, and 321 respectively. The mean percentages of total tree biomass as stem, branch and leaf respectively were 54, 43, and 3 for Chanfuta; 77, 22, and 1 for Jambire; and 46, 51, and 3 for Umbila. The best fit species-specific equation for estimating total above ground biomass (AGB was the power equation with only DBH considered as independent variable yielding coefficient of determination (R2 ranging from 0.89 to 0.97. At stand level, a total mean of 27.3 tons ha−1 biomass was determined of which studied species represented 94.6%. At plot level, total mean biomass for Jambire was 11.8 tons ha−1, Chanfuta and Umbila 9.9 and 4.1 tons ha−1 respectively. The developed power equation fitted total and stem biomass data well and could be used for biomass prediction of the studied species in Mozambique.

  10. Genera of diaporthalean coelomycetes associated with leaf spots of tree hosts

    NARCIS (Netherlands)

    Crous, P.W.; Summerell, B.A.; Alfenas, A.C.; Edwards, J.; Pascoe, I.G.; Porter, I.J.; Groenewald, J.Z.

    2012-01-01

    Four different genera of diaporthalean coelomycetous fungi associated with leaf spots of tree hosts are morphologically treated and phylogenetically compared based on the DNA sequence data of the large subunit nuclear ribosomal DNA gene (LSU) and the internal transcribed spacers and 5.8S rRNA gene

  11. Method for estimating potential tree-grade distributions for northeastern forest species

    Science.gov (United States)

    Daniel A. Yaussy; Daniel A. Yaussy

    1993-01-01

    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...

  12. A multigene species tree for Western Mediterranean painted frogs (Discoglossus).

    Science.gov (United States)

    Pabijan, Maciej; Crottini, Angelica; Reckwell, Dennis; Irisarri, Iker; Hauswaldt, J Susanne; Vences, Miguel

    2012-09-01

    Painted frogs (Discoglossus) are an anuran clade that originated in the Upper Miocene. Extant species are morphologically similar and have a circum-Mediterranean distribution. We assembled a multilocus dataset from seven nuclear and four mitochondrial genes for several individuals of all but one of the extant species and reconstructed a robust phylogeny by applying a coalescent-based species-tree method and a concatenation approach, both of which gave congruent results. The earliest phylogenetic split within Discoglossus separates D. montalentii from a clade comprising all other species. Discoglossus montalentii is monophyletic for haplotype variation at all loci and has distinct morphological, bioacoustic and karyotypic characters. We find moderate support for a sister-group relationship between the Iberian taxa and the Moroccan D. scovazzi, and high support for a D. pictus -D. sardus clade distributed around the Tyrrhenian basin. Topological discordance among gene trees during the speciation of D. galganoi, D. scovazzi, D. pictus and D. sardus is interpreted as the consequence of nearly simultaneous, vicariant diversification. The timing of these events is unclear, but possibly coincided with the final geotectonic rearrangement of the Western Mediterranean in the Middle Miocene or later during the Messinian salinity crisis. The Iberian taxa D. galganoi galganoi and D. g. jeanneae are reciprocally monophyletic in mitochondrial DNA but not in nuclear gene trees, and are therefore treated as subspecies of D. galganoi. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Impact of gene family evolutionary histories on phylogenetic species tree inference by gene tree parsimony.

    Science.gov (United States)

    Shi, Tao

    2016-03-01

    Complicated history of gene duplication and loss brings challenge to molecular phylogenetic inference, especially in deep phylogenies. However, phylogenomic approaches, such as gene tree parsimony (GTP), show advantage over some other approaches in its ability to use gene families with duplications. GTP searches the 'optimal' species tree by minimizing the total cost of biological events such as duplications, but accuracy of GTP and phylogenetic signal in the context of different gene families with distinct histories of duplication and loss are unclear. To evaluate how different evolutionary properties of different gene families can impact on species tree inference, 3900 gene families from seven angiosperms encompassing a wide range of gene content, lineage-specific expansions and contractions were analyzed. It was found that the gene content and total duplication number in a gene family strongly influence species tree inference accuracy, with the highest accuracy achieved at either very low or very high gene content (or duplication number) and lowest accuracy centered in intermediate gene content (or duplication number), as the relationship can fit a binomial regression. Besides, for gene families of similar level of average gene content, those with relatively higher lineage-specific expansion or duplication rates tend to show lower accuracy. Additional correlation tests support that high accuracy for those gene families with large gene content may rely on abundant ancestral copies to provide many subtrees to resolve conflicts, whereas high accuracy for single or low copy gene families are just subject to sequence substitution per se. Very low accuracy reached by gene families of intermediate gene content or duplication number can be due to insufficient subtrees to resolve the conflicts from loss of alternative copies. As these evolutionary properties can significantly influence species tree accuracy, I discussed the potential weighting of the duplication cost by

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-28

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

  15. Below- and above-ground tree species diversity in natural forest and ...

    African Journals Online (AJOL)

    The conversion of natural forests to monoculture tree plantations (MTPs) has been known to reduce above-ground tree diversity. However, information is lacking on the impact of MTPs on below-ground tree species diversity. This study evaluated below- and above-ground tree species diversity in a Strict Nature Reserve ...

  16. Novel Phaeoacremonium species associated with necrotic wood of Prunus trees

    NARCIS (Netherlands)

    Damm, U.; Mostert, L.; Crous, P.W.; Fourie, P.H.

    2008-01-01

    The genus Phaeoacremonium is associated with opportunistic human infections, as well as stunted growth and die-back of various woody hosts, especially grapevines. In this study, Phaeoacremonium species were isolated from necrotic woody tissue of Prunus spp. (plum, peach, nectarine and apricot) from

  17. Differential responses in sympatric tree species exposed to waterlogging.

    Science.gov (United States)

    Dat, James F; Parent, Claire

    2012-02-01

    Climate change is projected to have a significant ecological impact on natural ecosystems, most notably through direct and indirect modifications of local precipitation regimes. In addition, anthropic activities such as the removal of vegetation, soil proofing due to building, the absence of storm drains and crop over-irrigation will all increase the occurrence of flooding. As a result, forest species, and more specifically trees, will increasingly be exposed to soil waterlogging. It is now well established that such flooding events can lead to changes in forest distribution and composition. For such reasons, it is becoming increasingly important to study forest ecosystems and more particularly the adaptive potential of tree species to better understand the ecological plasticity of forest communities to environmental modifications.

  18. Climatic extremes improve predictions of spatial patterns of tree species

    Science.gov (United States)

    Zimmermann, N.E.; Yoccoz, N.G.; Edwards, T.C.; Meier, E.S.; Thuiller, W.; Guisan, Antoine; Schmatz, D.R.; Pearman, P.B.

    2009-01-01

    Understanding niche evolution, dynamics, and the response of species to climate change requires knowledge of the determinants of the environmental niche and species range limits. Mean values of climatic variables are often used in such analyses. In contrast, the increasing frequency of climate extremes suggests the importance of understanding their additional influence on range limits. Here, we assess how measures representing climate extremes (i.e., interannual variability in climate parameters) explain and predict spatial patterns of 11 tree species in Switzerland. We find clear, although comparably small, improvement (+20% in adjusted D2, +8% and +3% in cross-validated True Skill Statistic and area under the receiver operating characteristics curve values) in models that use measures of extremes in addition to means. The primary effect of including information on climate extremes is a correction of local overprediction and underprediction. Our results demonstrate that measures of climate extremes are important for understanding the climatic limits of tree species and assessing species niche characteristics. The inclusion of climate variability likely will improve models of species range limits under future conditions, where changes in mean climate and increased variability are expected.

  19. Is induction ability of seed germination of Phelipanche ramosa phylogenetically structured among hosts? A case study on Fabaceae species.

    Science.gov (United States)

    Perronne, Rémi; Gibot-Leclerc, Stéphanie; Dessaint, Fabrice; Reibel, Carole; Le Corre, Valérie

    2017-12-01

    Phelipanche ramosa is a major root-holoparasitic damaging weed characterized by a broad host range, including numerous Fabaceae species. In France, the agricultural threat posed by P. ramosa has increased over two decades due to the appearance of a genetically differentiated pathovar presenting a clear host specificity for oilseed rape. The new pathovar has led to a massive expansion of P. ramosa in oilseed rape fields. The germination rate of P. ramosa seeds is currently known to vary among P. ramosa pathovars and host species. However, only a few studies have investigated whether phylogenetic relatedness among potential host species is a predictor of the ability of these species to induce the seed germination of parasitic weeds by testing for phylogenetic signal. We focused on a set of 12 Fabaceae species and we assessed the rate of induction of seed germination by these species for two pathovars based on in vitro co-cultivation experiments. All Fabaceae species tested induced the germination of P. ramosa seeds. The germination rate of P. ramosa seeds varied between Fabaceae species and tribes studied, while pathovars appeared non-influential. Considering oilseed rape as a reference species, we also highlighted a significant phylogenetic signal. Phylogenetically related species therefore showed more similar rates of induction of seed germination than species drawn at random from a phylogenetic tree. In in vitro conditions, only Lotus corniculatus induced a significantly higher germination rate than oilseed rape, and could potentially be used as a catch crop after confirmation of these results under field conditions.

  20. Determinants of host species range in plant viruses.

    Science.gov (United States)

    Moury, Benoît; Fabre, Frédéric; Hébrard, Eugénie; Froissart, Rémy

    2017-04-01

    Prediction of pathogen emergence is an important field of research, both in human health and in agronomy. Most studies of pathogen emergence have focused on the ecological or anthropic factors involved rather than on the role of intrinsic pathogen properties. The capacity of pathogens to infect a large set of host species, i.e. to possess a large host range breadth (HRB), is tightly linked to their emergence propensity. Using an extensive plant virus database, we found that four traits related to virus genome or transmission properties were strongly and robustly linked to virus HRB. Broader host ranges were observed for viruses with single-stranded genomes, those with three genome segments and nematode-transmitted viruses. Also, two contrasted groups of seed-transmitted viruses were evidenced. Those with a single-stranded genome had larger HRB than non-seed-transmitted viruses, whereas those with a double-stranded genome (almost exclusively RNA) had an extremely small HRB. From the plant side, the family taxonomic rank appeared as a critical threshold for virus host range, with a highly significant increase in barriers to infection between plant families. Accordingly, the plant-virus infectivity matrix shows a dual structure pattern: a modular pattern mainly due to viruses specialized to infect plants of a given family and a nested pattern due to generalist viruses. These results contribute to a better prediction of virus host jumps and emergence risks.

  1. Are cryptic host species also cryptic to parasites? Host specificity and geographical distribution of acanthocephalan parasites infecting freshwater Gammarus.

    Science.gov (United States)

    Westram, A M; Baumgartner, C; Keller, I; Jokela, J

    2011-07-01

    Many parasites infect multiple host species. In coevolving host-parasite interactions, theory predicts that parasites should be adapted to locally common hosts, which could lead to regional shifts in host preferences. We studied the interaction between freshwater Gammarus (Crustacea, Amphipoda) and their acanthocephalan parasites using a large-scale field survey and experiments, combined with molecular identification of cryptic host and parasite species. Gammarus pulex is a common host for multiple species of Acanthocephala in Europe but, in Switzerland, is less common than two cryptic members of the Gammarus fossarum species complex (type A and type B). We found that natural populations of these cryptic species were frequently infected by Pomphorhynchus tereticollis and Polymorphus minutus. Four additional parasite species occurred only locally. Parasites were more common in G. fossarum type B than in type A. Infection experiments using several host and parasite sources confirmed consistently lower infection rates in G. pulex than in G. fossarum type A, suggesting a general difference in susceptibility between the two species. In conclusion, we could show that cryptic host species differ in their interactions with parasites, but that these differences were much less dramatic than differences between G. fossarum (type A) and G. pulex. Our data suggest that the acanthocephalans in Switzerland have adapted to the two most common Gammarus species in this region where host species frequencies differ from near-by regions in Europe. Copyright © 2011 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    William B. Leak; Mariko. Yamasaki

    2012-01-01

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

  3. Carbon and nitrogen in forest floor and mineral soil under six common European tree species

    DEFF Research Database (Denmark)

    Vesterdal, Lars; Schmidt, Inger K.; Callesen, Ingeborg

    2007-01-01

    The knowledge of tree species effects on soil C and N pools is scarce, particularly for European deciduous tree species. We studied forest floor and mineral soil carbon and nitrogen under six common European tree species in a common garden design replicated at six sites in Denmark. Three decades...

  4. Temporal and Directional Patterns of Nymphal Halyomorpha halys (Hemiptera: Pentatomidae) Movement on the Trunk of Selected Wild and Fruit Tree Hosts in the Mid-Atlantic Region.

    Science.gov (United States)

    Acebes-Doria, Angelita L; Leskey, Tracy C; Bergh, J Christopher

    2017-04-01

    Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive and polyphagous herbivore that has been problematic in Mid-Atlantic fruit orchards, many of which are adjacent to woodlands containing its wild hosts. Our tree census in woodlands bordering 15 Mid-Atlantic apple orchards revealed 47 species of deciduous trees and shrubs, 76.6% of which were recorded hosts of H. halys. Tree of heaven was most common and abundant overall. Halyomorpha halys nymphs have a substantial walking dispersal capacity, and their fitness is enhanced by feeding on multiple hosts. Directional and temporal patterns of nymphal H. halys movement on selected wild hosts and apple and peach trees at the orchard-woodland interface were monitored in 2014 and 2015 using passive traps to capture nymphs walking up and down tree trunks. Weekly captures from mid-May to late September or mid-October were compared among hosts across both seasons. Despite higher total nymphal captures in 2014 than 2015, the seasonal trends for both years were similar and indicated bivoltine H. halys populations. In both years, more nymphs were intercepted while walking up than down and captures of upward- and downward-walking nymphs varied significantly among the hosts. All instars were captured, but captures of second instars predominated. Captures reflected seasonal changes in instar distribution and consisted predominantly of younger and older nymphs, early and later in the season, respectively. Results are discussed in relation to host and seasonal effects on the movement of nymphs at the orchard-woodland interface, and the implications for H. halys management. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2017-04-01

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

  6. The influence of gene flow on species tree estimation: a simulation study.

    Science.gov (United States)

    Leaché, Adam D; Harris, Rebecca B; Rannala, Bruce; Yang, Ziheng

    2014-01-01

    Gene flow among populations or species and incomplete lineage sorting (ILS) are two evolutionary processes responsible for generating gene tree discordance and therefore hindering species tree estimation. Numerous studies have evaluated the impacts of ILS on species tree inference, yet the ramifications of gene flow on species trees remain less studied. Here, we simulate and analyse multilocus sequence data generated with ILS and gene flow to quantify their impacts on species tree inference. We characterize species tree estimation errors under various models of gene flow, such as the isolation-migration model, the n-island model, and gene flow between non-sister species or involving ancestral species, and species boundaries crossed by a single gene copy (allelic introgression) or by a single migrant individual. These patterns of gene flow are explored on species trees of different sizes (4 vs. 10 species), at different time scales (shallow vs. deep), and with different migration rates. Species trees are estimated with the multispecies coalescent model using Bayesian methods (BEST and *BEAST) and with a summary statistic approach (MPEST) that facilitates phylogenomic-scale analysis. Even in cases where the topology of the species tree is estimated with high accuracy, we find that gene flow can result in overestimates of population sizes (species tree dilation) and underestimates of species divergence times (species tree compression). Signatures of migration events remain present in the distribution of coalescent times for gene trees, and with sufficient data it is possible to identify those loci that have crossed species boundaries. These results highlight the need for careful sampling design in phylogeographic and species delimitation studies as gene flow, introgression, or incorrect sample assignments can bias the estimation of the species tree topology and of parameter estimates such as population sizes and divergence times.

  7. Panamanian frog species host unique skin bacterial communities

    Directory of Open Access Journals (Sweden)

    Lisa K. Belden

    2015-10-01

    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  8. VEGETATIVE MORPHOLOGY FOR SPECIES IDENTIFICATION OF TROPICAL TREES: FAMILY DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Peter Hargreaves

    2006-03-01

    Full Text Available Tree specimens from the ESAL herbarium of the Universidade Federal de Lavras, Minas Gerais, Brazil, were describedby vegetative characteristics using CARipé, a Microsoft Access database application specially developed for this study. Only onespecimen per species was usually described. Thus, 2 observers described 567 herbarium species as a base to test methods ofidentification as part of a larger study. The present work formed part of that study and provides information on the distribution of22 vegetative characters among 16 families having 10 or more species described. The characters are discussed. The study foundmarked differences, even discontinuities, of distributions of characters between those families. Therefore it should be possible toincorporate phylogenetic relationships into the identification process.

  9. Trophic relationships between the parasitic plant species Phelipanche ramosa (L. and different hosts depending on host phenological stage and host growth rate

    Directory of Open Access Journals (Sweden)

    Delphine Moreau

    2016-07-01

    Full Text Available Phelipanche ramosa (L. Pomel (branched broomrape is a holoparasitic plant that reproduces on crops and also on weeds, which contributes to increase the parasite seed bank in fields. This parasite extracts all its nutrients at the host's expense so that host-parasite trophic relationships are crucial to determine host and parasite growth. This study quantified the intensity with which P. ramosa draws assimilates from its host and analyzed whether it varied with host species, host phenological stage and host growth rate. A greenhouse experiment was conducted on three host species: the crop species Brassica napus (L. (oilseed rape and two weed species, Capsella bursa-pastoris (L. Medik. and Geranium dissectum (L.. Plants were grown with or without P. ramosa and under three light levels to modulate host growth rate. The proportion of host biomass loss due to parasitism by P. ramosa differed between host species (at host fructification, biomass loss ranged from 34% to 84%. Brassica napus and C. bursa-pastoris displayed a similar response to P. ramosa, probably because they belong to the same botanical family. The sensitivity to P. ramosa in each host species could be related to the precocity of P. ramosa development on them. Host compartments could be ranked as a function of their sensitivity to parasitism, with the reproductive compartment being the most severely affected, followed by stems and roots. The proportion of biomass allocated to leaves was not reduced by parasitism. The proportion of pathosystem biomass allocated to the parasite depended on host species. It generally increased with host stage progression but was constant across light induced-host growth rate, showing that P. ramosa adapts its growth to host biomass production. The rank order of host species in terms of sink strength differed from that in terms of host sensitivity. Finally, for B. napus, the biomass of individual parasite shoots decreased with increasing their number per

  10. Accounting for Uncertainty in Gene Tree Estimation: Summary-Coalescent Species Tree Inference in a Challenging Radiation of Australian Lizards.

    Science.gov (United States)

    Blom, Mozes P K; Bragg, Jason G; Potter, Sally; Moritz, Craig

    2017-05-01

    Accurate gene tree inference is an important aspect of species tree estimation in a summary-coalescent framework. Yet, in empirical studies, inferred gene trees differ in accuracy due to stochastic variation in phylogenetic signal between targeted loci. Empiricists should, therefore, examine the consistency of species tree inference, while accounting for the observed heterogeneity in gene tree resolution of phylogenomic data sets. Here, we assess the impact of gene tree estimation error on summary-coalescent species tree inference by screening ${\\sim}2000$ exonic loci based on gene tree resolution prior to phylogenetic inference. We focus on a phylogenetically challenging radiation of Australian lizards (genus Cryptoblepharus, Scincidae) and explore effects on topology and support. We identify a well-supported topology based on all loci and find that a relatively small number of high-resolution gene trees can be sufficient to converge on the same topology. Adding gene trees with decreasing resolution produced a generally consistent topology, and increased confidence for specific bipartitions that were poorly supported when using a small number of informative loci. This corroborates coalescent-based simulation studies that have highlighted the need for a large number of loci to confidently resolve challenging relationships and refutes the notion that low-resolution gene trees introduce phylogenetic noise. Further, our study also highlights the value of quantifying changes in nodal support across locus subsets of increasing size (but decreasing gene tree resolution). Such detailed analyses can reveal anomalous fluctuations in support at some nodes, suggesting the possibility of model violation. By characterizing the heterogeneity in phylogenetic signal among loci, we can account for uncertainty in gene tree estimation and assess its effect on the consistency of the species tree estimate. We suggest that the evaluation of gene tree resolution should be incorporated

  11. BIOMASS ALLOMETRY FOR TREE SPECIES OF NORTHWESTERN MEXICO

    Directory of Open Access Journals (Sweden)

    Jose de Jesus Navar Chaidez

    2010-02-01

    Full Text Available Tree biomass plays a key role in sustainable forest management since it is the basis for estimating stocks and fluxes of several biogeochemical elements, the amount of energy stored in biomass, and other conventional goods and services. The most common mathematical model takes the form of the logarithmic equation where biomass is estimated as a function of diameter at breast height with the scaling coefficients a and B. In this study, I answered the following questions related with the allometric model: a Is it important to develop biomass equations at the species scale or at the site-specific scale?; b What is the least number of data required for fitting an allometric equation?; and c Is it possible to develop allometric equations with few or null biomass data without loosing accuracy in biomass estimation? I employed a biomass data source collected in northwestern Mexico for nine different forest species, collected in six different sites from southern Chihuahua to southern Durango, Mexico to answer these questions. Results showed that by fitting site-specific biomass equations there is a net gain of 5% and close to 20% in the coefficient of determination and the standard error, respectively in contrast to fitting an equation at the species level. The minimum number of observations needed is 60 harvested trees to calculate parameters with the least variance and with high consistency. I present two alternate restrictive methods of biomass estimation: a restricting the number of harvested trees to three to fit equations available in the scientific literature and b a non-destructive model to fit equations with the same level of accuracy that display conventional allometric models. Both methods estimate biomass within the confidence bounds imposed on the B coefficient of the conventional allometric model.

  12. Resprouting from roots in four Brazilian tree species.

    Science.gov (United States)

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

    2009-09-01

    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

  13. Generalized biomass and leaf area allometric equations for European tree species incorporating stand structure, tree age and climate

    OpenAIRE

    FORRESTER DAVID; TACHAUER ELOISE; ANNIGHOEFER PETER; BARBEITO IGNACIO; PRETZSCH HANS; RUIZ-PEINADO RICARDO; STARK HENDRIK; VACCHIANO GIORGIO; ZLATANOV TZVETAN; CHAKRABORTY TAMALIKA; SAHA SOMID; SILESHI GUDETA W.

    2017-01-01

    Biomass and leaf area equations are often required to assess or model forest productivity, carbon stocks and other ecosystem services. These factors are influenced by climate, age and stand structural attributes including stand density and tree species diversity or species composition. However, such covariates are rarely included in biomass and leaf area equations. We reviewed the literature and built a database of biomass and leaf area equations for 24 European tree species and 3 introduced ...

  14. Host switching in a generalist parasitoid: contrasting transient and transgenerational costs associated with novel and original host species

    Science.gov (United States)

    Jones, Thomas S; Bilton, Adam R; Mak, Lorraine; Sait, Steven M

    2015-01-01

    Parasitoids face challenges by switching between host species that influence survival and fitness, determine their role in structuring communities, influence species invasions, and affect their importance as biocontrol agents. In the generalist parasitoid, Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae), we investigated the costs in encapsulation, survival, and body size on juveniles when adult parasitoids switched from their original host, Plodia interpunctella (Hübner) (Lepidotera, Pyralidae) to a novel host, Ephestia kuehniella (Zeller) (Lepidoptera, Pyralidae), over multiple generations. Switching had an initial survival cost for juvenile parasitoids in the novel host, but increased survival occurred within two generations. Conversely, mortality in the original host increased. Body size, a proxy for fecundity, also increased with the number of generations in the novel host species, reflecting adaptation or maternal effects due to the larger size of the novel host, and therefore greater resources available to the developing parasitoid. Switching to a novel host appears to have initial costs for a parasitoid, even when the novel host may be better quality, but the costs rapidly diminish. We predict that the net cost of switching to a novel host for parasitoids will be complex and will depend on the initial reduction in fitness from parasitizing a novel host versus local adaptations against parasitoids in the original host. PMID:25691971

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

    DEFF Research Database (Denmark)

    Nord-Larsen, Thomas; Meilby, Henrik

    2016-01-01

    Growing concern about increasing concentrations of greenhouse gases in the atmosphere, and resulting global climate change, has spurred a growing demand for renewable energy. In this study, we hypothesized that a nurse tree crop may provide additional early yields of biomass for fuel, while...... in the longterm leading to deciduous stands that are believed to better meet the demands for other ecosystem services. Ten different species combinations were planted, with two different stocking densities, at three different sites in Denmark. Significant differences, with regard to biomass production, were...... observed among the different sites (P biomass. The additional biomass production was similar to what was obtained in stands...

  16. Occurrence of Rare Tree and Shrub Species in Hungary

    Directory of Open Access Journals (Sweden)

    BARTHA, Dénes

    2005-01-01

    Full Text Available The Department of Botany has been focusing on investigating rare taxa of theHungarian dendroflora since 1989. The research dealt with nearly 50 species regarding conditions of occurrence, habitat preference, reproduction and possible conservational management up to 2003. In the investigation of species, chorology was of primary importance. Since 1993 occurrence data have been systematically collected. As a first result, CEU grid-maps of 142 species, including all the rare dendrotaxa in Hungary, were published (Bartha – Mátyás 1995 using grid squares of 10' long. × 6' lat. equalling approx. 12 × 11 km. With organizational and methodological experience, focuses have moved to processing, correction and mapping of reference, herbaria and new field records. A detailed evaluation of the distribution of 34 rare species in Hungary was made and published (Bartha et al 1999. The Department of Botany at the University of West Hungary has been project coordinator of ‘Floristic Mapping of Hungary’ since 2001. The present study describes actual distribution maps of 20 rare tree- and shrub species with short analyses of their conditions in Hungary.

  17. Neogene origins and implied warmth tolerance of Amazon tree species.

    Science.gov (United States)

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

    2012-01-01

    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.

  18. Flowering phenology of selected wind pollinated allergenic deciduous tree species

    Directory of Open Access Journals (Sweden)

    Magdalena Kluza-Wieloch

    2012-12-01

    Full Text Available Systematic phenological observations have been carried out in the Dendrological Garden of August Cieszkowski Agricultural University, Park Sołacki, Lasek Golęciński, Przybyszewskiego Street, for two years (2003, 2004. The selected species of deciduous trees, as Betula pendula, Corylus avellana, Platanus x hispanica. There was interdependence between the course of flowering process and weather conditions. Long and frosty winter at the turn of 2002/2003 and subzero mean temperatures in the first quarter of 2003 delayed vegetation. Rapid coming of early spring in the year 2004 accelerate the development of generative organs. Each year spring ground frost during flowering did not inhibit this process. All the investigated tree species are anemophilous and produce large amounts of allergenic pollen grain. They cause allergic reactions throughout the whole period of pollen discharge. Male inflorescences in Corylus avellana, blooming very early, are one of the first plants causing allergic reactions. Betula pendula is the next to bloom, followed by Platanus x hispanica. Observations of phenological phases may provide useful information forecasting the beginning of the period of increased pollen concentration in air.

  19. A comparative analysis of genetic differentiation across six shared willow host species in leaf- and bud-galling sawflies.

    Directory of Open Access Journals (Sweden)

    Sanna A Leppänen

    Full Text Available Genetic divergence and speciation in plant-feeding insects could be driven by contrasting selection pressures imposed by different plant species and taxa. While numerous examples of host-associated differentiation (HAD have been found, the overall importance of HAD in insect diversification remains unclear, as few studies have investigated its frequency in relation to all speciation events. One promising way to infer the prevalence and repeatability of HAD is to estimate genetic differentiation in multiple insect taxa that use the same set of hosts. To this end, we measured and compared variation in mitochondrial COI and nuclear ITS2 sequences in population samples of leaf-galling Pontania and bud-galling Euura sawflies (Hymenoptera: Tenthredinidae collected from six Salix species in two replicate locations in northern Fennoscandia. We found evidence of frequent HAD in both species complexes, as individuals from the same willow species tended to cluster together on both mitochondrial and nuclear phylogenetic trees. Although few fixed differences among the putative species were found, hierarchical AMOVAs showed that most of the genetic variation in the samples was explained by host species rather than by sampling location. Nevertheless, the levels of HAD measured across specific pairs of host species were not correlated in the two focal galler groups. Hence, our results support the hypothesis of HAD as a central force in herbivore speciation, but also indicate that evolutionary trajectories are only weakly repeatable even in temporally overlapping radiations of related insect taxa.

  20. Rapid diagnosis of the infection of pine tree with pine wood nematode (Bursaphelenchus xylophilus) by use of host-tree volatiles.

    Science.gov (United States)

    Yun, Ji Eun; Kim, Junheon; Park, Chung Gyoo

    2012-08-01

    Attraction of the Bursaphelenchus xylophilus nematode toward 18 volatiles of Pinus species was evaluated by a Petri-dish bioassay under laboratory conditions to develop a rapid diagnostic kit. Among these compounds, α-pinene, β-pinene, and camphor showed significantly higher attractiveness to B. xylophilus in both the reproductive and dispersal stages, whereas these compounds were not active against Bursaphelenchus mucronatus . A trap tube was developed as a diagnostic kit, which consisted of a tube filled with 0.8% agar and a matrix impregnated with an attractant: α-pinene, β-pinene, or camphor. All tested compounds attracted a significantly higher number of B. xylophilus than that in the control treatment. No significant difference was observed among attractants. The cotton-ball matrix was significantly more effective than the filter-paper matrix for attracting B. xylophilus in the artificial pupal chamber bioassay. In a bioassay with pine wood nematode (PWN)-infected pine tree logs, B. xylophilus was initially attracted after an 8 h trap period and the number of B. xylophilus increased with time. The trap tube using camphor and the cotton-ball matrix were most effective for attracting B. xylophilus . The semiochemical-based tube-trapping method is simple to use, requires minimal labor, and is economical and effective for detecting B. xylophilus living in host pine trees during field sampling.

  1. Temperate tree species show identical response in tree water deficit but different sensitivities in sap flow to summer soil drying.

    Science.gov (United States)

    Brinkmann, Nadine; Eugster, Werner; Zweifel, Roman; Buchmann, Nina; Kahmen, Ansgar

    2016-12-01

    Temperate forests are expected to be particularly vulnerable to drought and soil drying because they are not adapted to such conditions and perform best in mesic environments. Here we ask (i) how sensitively four common temperate tree species (Fagus sylvatica, Picea abies, Acer pseudoplatanus and Fraxinus excelsior) respond in their water relations to summer soil drying and seek to determine (ii) if species-specific responses to summer soil drying are related to the onset of declining water status across the four species. Throughout 2012 and 2013 we determined tree water deficit (TWD) as a proxy for tree water status from recorded stem radius changes and monitored sap flow rates with sensors on 16 mature trees studied in the field at Lägeren, Switzerland. All tree species responded equally in their relative maximum TWD to the onset of declining soil moisture. This implies that the water supply of all tree species was affected by declining soil moisture and that none of the four species was able to fully maintain its water status, e.g., by access to alternative water sources in the soil. In contrast we found strong and highly species-specific responses of sap flow to declining soil moisture with the strongest decline in P. abies (92%), followed by F. sylvatica (53%) and A. pseudoplatanus (48%). F. excelsior did not significantly reduce sap flow. We hypothesize the species-specific responses in sap flow to declining soil moisture that occur despite a simultaneous increase in relative TWD in all species reflect how fast these species approach critical levels of their water status, which is most likely influenced by species-specific traits determining the hydraulic properties of the species tree. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Effects of drought and vegetation management on the establishment of 3 tree species in Northamptonshire, England

    OpenAIRE

    Panter, Jonathan Paul

    2006-01-01

    Water is a limiting factor in the distribution and growth of trees. Changing climatic conditions are likely to significantly effect tree species development. The planting and establishment of trees needs to take into account these changing factors in terms of design and species selection. This study looked at survival and growth of newly planted trees under field scale conditions and the effects of soil water availability and ground treatments. The experiment followed a blocked...

  3. A study on crown interception with four dominant tree species: a direct measurement

    Science.gov (United States)

    Xiang Li; Jianzhi Niu; Linus Zhang; Qingfu Xiao; Gregory E. McPherson; Natalie van Doorn; Xinxiao Yu; Baoyuan Xie; Salli Dymond; Jiao Li; Chen Meng; Ziteng Luo

    2016-01-01

    An experiment was conducted to concentrate on the rainfall interception process of individual trees for four common species in Beijing, China, which included needle species (Platycladus orientalis and Pinus tabulaeformis) and broadleaf species (Quercus variabilis and Acer truncatum)....

  4. The integrative taxonomic approach reveals host specific species in an encyrtid parasitoid species complex.

    Directory of Open Access Journals (Sweden)

    Douglas Chesters

    Full Text Available Integrated taxonomy uses evidence from a number of different character types to delimit species and other natural groupings. While this approach has been advocated recently, and should be of particular utility in the case of diminutive insect parasitoids, there are relatively few examples of its application in these taxa. Here, we use an integrated framework to delimit independent lineages in Encyrtus sasakii (Hymenoptera: Chalcidoidea: Encyrtidae, a parasitoid morphospecies previously considered a host generalist. Sequence variation at the DNA barcode (cytochrome c oxidase I, COI and nuclear 28S rDNA loci were compared to morphometric recordings and mating compatibility tests, among samples of this species complex collected from its four scale insect hosts, covering a broad geographic range of northern and central China. Our results reveal that Encyrtus sasakii comprises three lineages that, while sharing a similar morphology, are highly divergent at the molecular level. At the barcode locus, the median K2P molecular distance between individuals from three primary populations was found to be 11.3%, well outside the divergence usually observed between Chalcidoidea conspecifics (0.5%. Corroborative evidence that the genetic lineages represent independent species was found from mating tests, where compatibility was observed only within populations, and morphometric analysis, which found that despite apparent morphological homogeneity, populations clustered according to forewing shape. The independent lineages defined by the integrated analysis correspond to the three scale insect hosts, suggesting the presence of host specific cryptic species. The finding of hidden host specificity in this species complex demonstrates the critical role that DNA barcoding will increasingly play in revealing hidden biodiversity in taxa that present difficulties for traditional taxonomic approaches.

  5. Above ground biomass and tree species richness estimation with airborne lidar in tropical Ghana forests

    Science.gov (United States)

    Vaglio Laurin, Gaia; Puletti, Nicola; Chen, Qi; Corona, Piermaria; Papale, Dario; Valentini, Riccardo

    2016-10-01

    Estimates of forest aboveground biomass are fundamental for carbon monitoring and accounting; delivering information at very high spatial resolution is especially valuable for local management, conservation and selective logging purposes. In tropical areas, hosting large biomass and biodiversity resources which are often threatened by unsustainable anthropogenic pressures, frequent forest resources monitoring is needed. Lidar is a powerful tool to estimate aboveground biomass at fine resolution; however its application in tropical forests has been limited, with high variability in the accuracy of results. Lidar pulses scan the forest vertical profile, and can provide structure information which is also linked to biodiversity. In the last decade the remote sensing of biodiversity has received great attention, but few studies focused on the use of lidar for assessing tree species richness in tropical forests. This research aims at estimating aboveground biomass and tree species richness using discrete return airborne lidar in Ghana forests. We tested an advanced statistical technique, Multivariate Adaptive Regression Splines (MARS), which does not require assumptions on data distribution or on the relationships between variables, being suitable for studying ecological variables. We compared the MARS regression results with those obtained by multilinear regression and found that both algorithms were effective, but MARS provided higher accuracy either for biomass (R2 = 0.72) and species richness (R2 = 0.64). We also noted strong correlation between biodiversity and biomass field values. Even if the forest areas under analysis are limited in extent and represent peculiar ecosystems, the preliminary indications produced by our study suggest that instrument such as lidar, specifically useful for pinpointing forest structure, can also be exploited as a support for tree species richness assessment.

  6. Tree Species Recognition in Species Rich Area Using Uav-Borne Hyperspectral Imagery and Stereo-Photogrammetric Point Cloud

    Science.gov (United States)

    Tuominen, S.; Näsi, R.; Honkavaara, E.; Balazs, A.; Hakala, T.; Viljanen, N.; Pölönen, I.; Saari, H.; Reinikainen, J.

    2017-10-01

    Recognition of tree species and geospatial information of tree species composition is essential for forest management. In this study we test tree species recognition using hyperspectral imagery from VNIR and SWIR camera sensors in combination with 3D photogrammetric canopy surface model based on RGB camera stereo-imagery. An arboretum forest with a high number of tree species was used as a test area. The imagery was acquired from the test area using UAV-borne cameras. Hyperspectral imagery was calibrated for providing a radiometrically corrected reflectance mosaic, which was tested along with the original uncalibrated imagery. Alternative estimators were tested for predicting tree species and genus, as well as for selecting an optimal set of remote sensing features for this task. All tested estimators gave similar trend in the results: the calibrated reflectance values performed better in predicting tree species and genus compared to uncorrected hyperspectral pixel values. Furthermore, the combination of VNIR, SWIR and 3D features performed better than any of the data sets individually, with calibrated reflectances and original pixel values alike. The highest proportion of correctly classified trees was achieved using calibrated reflectance features from VNIR and SWIR imagery together with 3D point cloud features: 0.823 for tree species and 0.869 for tree genus.

  7. Ephedra alte (Joint Pine): An Invasive, Problematic Weedy Species in Forestry and Fruit Tree Orchards in Jordan

    Science.gov (United States)

    Qasem, Jamal R.

    2012-01-01

    A field survey was carried out to record plant species climbed by Ephedra alte in certain parts of Jordan during 2008–2010. Forty species of shrubs, ornamental, fruit, and forest trees belonging to 24 plant families suffered from the climbing habit of E. alte. Growth of host plants was adversely affected by E. alte growth that extended over their vegetation. In addition to its possible competition for water and nutrients, the extensive growth it forms over host species prevents photosynthesis, smothers growth and makes plants die underneath the extensive cover. However, E. alte did not climb all plant species, indicating a host preference range. Damaged fruit trees included Amygdalus communis, Citrus aurantifolia, Ficus carica, Olea europaea, Opuntia ficus-indica, and Punica granatum. Forestry species that were adversely affected included Acacia cyanophylla, Ceratonia siliqua, Crataegus azarolus, Cupressus sempervirens, Pinus halepensis, Pistacia atlantica, Pistacia palaestina, Quercus coccifera, Quercus infectoria, Retama raetam, Rhamnus palaestina, Rhus tripartita, and Zizyphus spina-christi. Woody ornamentals attacked were Ailanthus altissima, Hedera helix, Jasminum fruticans, Jasminum grandiflorum, Nerium oleander, and Pyracantha coccinea. Results indicated that E. alte is a strong competitive for light and can completely smother plants supporting its growth. A. communis, F. carica, R. palaestina, and C. azarolus were most frequently attacked. PMID:22645486

  8. Ephedra alte (Joint Pine: An Invasive, Problematic Weedy Species in Forestry and Fruit Tree Orchards in Jordan

    Directory of Open Access Journals (Sweden)

    Jamal R. Qasem

    2012-01-01

    Full Text Available A field survey was carried out to record plant species climbed by Ephedra alte in certain parts of Jordan during 2008–2010. Forty species of shrubs, ornamental, fruit, and forest trees belonging to 24 plant families suffered from the climbing habit of E. alte. Growth of host plants was adversely affected by E. alte growth that extended over their vegetation. In addition to its possible competition for water and nutrients, the extensive growth it forms over host species prevents photosynthesis, smothers growth and makes plants die underneath the extensive cover. However, E. alte did not climb all plant species, indicating a host preference range. Damaged fruit trees included Amygdalus communis, Citrus aurantifolia, Ficus carica, Olea europaea, Opuntia ficus-indica, and Punica granatum. Forestry species that were adversely affected included Acacia cyanophylla, Ceratonia siliqua, Crataegus azarolus, Cupressus sempervirens, Pinus halepensis, Pistacia atlantica, Pistacia palaestina, Quercus coccifera, Quercus infectoria, Retama raetam, Rhamnus palaestina, Rhus tripartita, and Zizyphus spina-christi. Woody ornamentals attacked were Ailanthus altissima, Hedera helix, Jasminum fruticans, Jasminum grandiflorum, Nerium oleander, and Pyracantha coccinea. Results indicated that E. alte is a strong competitive for light and can completely smother plants supporting its growth. A. communis, F. carica, R. palaestina, and C. azarolus were most frequently attacked.

  9. Molecular and morphological analysis reveals five new species of Zygophiala associated with flyspeck signs on plant hosts from China.

    Directory of Open Access Journals (Sweden)

    Liu Gao

    Full Text Available Species in the genus Zygophiala are associated with sooty blotch and flyspeck disease on a wide range of hosts. In this study, 63 Zygophiala isolates collected from flyspeck colonies on a range of plants from several regions of China were used for phylogeny, host range and geographic distribution analysis. Phylogenetic trees were constructed on four genes--internal transcribed spacer (ITS, partial translation elongation factor 1-alpha (TEF, β-tubulin (TUB2, and actin (ACT--both individually and in combination. Isolates were grouped into 11 clades among which five new species, Z. emperorae, Z. trispora, Z. musae, Z. inaequalis and Z. longispora, were described. Species of Zygophiala differed in observed host range and geographic distribution. Z. wisconsinensis and Z. emperorae were the most prevalent throughout the sampled regions of China, whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were collected only in southern China. The hosts of Z. wisconsinensis and Z. emperorae were mainly in the family Rosaceae whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were found mainly on banana (Musa spp.. Cross inoculation tests provided evidence of host specificity among SBFS species.

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

    Science.gov (United States)

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

    2017-09-01

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

  11. SECTION-BASED TREE SPECIES IDENTIFICATION USING AIRBORNE LIDAR POINT CLOUD

    Directory of Open Access Journals (Sweden)

    C. Yao

    2017-09-01

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

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

    NARCIS (Netherlands)

    Dijkstra, F.A.

    2001-01-01

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

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

    DEFF Research Database (Denmark)

    Raulund-Rasmussen, Karsten; Vejre, Henrik

    1995-01-01

    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...... IMMOBILIZATION; SOIL PROPERTIES; SOIL SOLUTION; TREE SPECIES...

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

    Science.gov (United States)

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

    2012-01-01

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

  15. A United States national prioritization framework for tree species vulnerability to climate change

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane; William W. Hargrove

    2017-01-01

    Climate change is one of several threats that will increase the likelihood that forest tree species could experience population-level extirpation or species-level extinction. Scientists and managers from throughout the United States Forest Service have cooperated to develop a framework for conservation priority-setting assessments of forest tree species. This framework...

  16. Tree species and functional traits but not species richness affect interrill erosion processes in young subtropical forests

    Science.gov (United States)

    Seitz, S.; Goebes, P.; Song, Z.; Bruelheide, H.; Härdtle, W.; Kühn, P.; Li, Y.; Scholten, T.

    2016-01-01

    Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale run-off plots was conducted to investigate the influence of tree species and tree species richness as well as functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 Mg ha-1 a-1 was calculated. This study provided evidence that different tree species affect interrill erosion differently, while tree species richness did not affect interrill erosion in young forest stands. Thus, different tree morphologies have to be considered, when assessing soil erosion under forest. High crown cover and leaf area index reduced interrill erosion in initial forest ecosystems, whereas rising tree height increased it. Even if a leaf litter cover was not present, the remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on interrill erosion. Long-term monitoring of soil erosion under closing tree canopies is necessary, and a wide range of functional tree traits should be considered in future research.

  17. Branch-and-bound approach for parsimonious inference of a species tree from a set of gene family trees.

    Science.gov (United States)

    Doyon, Jean-Philippe; Chauve, Cedric

    2011-01-01

    We describe a Branch-and-Bound algorithm for computing a parsimonious species tree, given a set of gene family trees. Our algorithm can consider three cost measures: number of gene duplications, number of gene losses, and both combined. Moreover, to cope with intrinsic limitations of Branch-and-Bound algorithms for species trees inference regarding the number of taxa that can be considered, our algorithm can naturally take into account predefined relationships between sets of taxa. We test our algorithm on a dataset of eukaryotic gene families spanning 29 taxa.

  18. Chemical ecology of bark beetles in regard to search and selection of host trees

    Science.gov (United States)

    Bark beetles (Coleoptera: Scolytidae), especially pests in the genera Dendroctonus, Ips, Scolytus, Trypodendron, Tomicus, and Pityogenes of the Northern hemisphere are reviewed regarding aspects of their chemical ecology during host finding and selection. Most of the species covered here feed on con...

  19. Iodine uptake and distribution in horticultural and fruit tree species

    Directory of Open Access Journals (Sweden)

    Alessandra Caffagni

    2012-07-01

    Full Text Available Iodine is an essential microelement for humans and iodine deficiency disorder (IDD is one of the most widespread nutrient-deficiency diseases in the world. Iodine biofortification of plants provides an attractive opportunity to increase iodine intake in humans and to prevent and control IDD. This study was conducted to investigate the iodine uptake and accumulation in edible portion of two fruit trees: plum and nectarine, and two horticultural crops: tomato and potato. Two type of iodine treatments (soil and foliar spray application, and, for fresh market tomato, two production systems (open field and greenhouse hydroponic culture were tested. The distribution of iodine in potato stem and leaves, and in plum tree fruits, leaves, and branches was investigated. Iodine content of potato tubers after postharvest storage and processing (cooking, and iodine content of nectarine fruits after postharvest storage and processing (peeling were also determined. Differences in iodine accumulation were observed among the four crops, between applications, and between production systems. In open field, the maximum iodine content ranged from 9.5 and 14.3 μg 100 g−1 for plum and nectarine fruit, to 89.4 and 144.0 μg 100 g−1 for potato tuber and tomato fruit, respectively. These results showed that nectarine and plum tree accumulated significantly lower amounts of iodine in their edible tissues, in comparison with potato and tomato. The experiments also indicated hydroponic culture as the most efficient system for iodine uptake in tomato, since its fresh fruits accumulated up to 2423 μg 100 g−1 of iodine. Iodine was stored mainly in the leaves, in all species investigated. Only a small portion of iodine was moved to plum tree branches and fruits, and to potato stems and tubers. No differences in iodine content after fruit peeling was observed. A significant increase in iodine content of potato was observed after baking, whereas a significant decrease was

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    European broadleaved tree species and Norway spruce.Litter δ15N and 15N enrichment factor (δ15Nlitter–δ15Nsoil) were positively correlated with N status based on soil and litter N pools, nitrification, subsoil nitrate concentration and forest growth. Tree species differences were also significant...... for these N variables and for the litter δ15N and enrichment factor. Litter from ash and sycamore maple with high N status and low fungal mycelia activity was enriched in 15N (+0.9 delta units) relative to other tree species (European beech, pedunculate oak, lime and Norway spruce) even though the latter...

  1. Nutrition facts and limits for micronutrients in tree species used in urban forestry

    OpenAIRE

    FLÁVIA G.K. BRUN; ELEANDRO J. BRUN; DIONATAN GERBER; DENISE A. SZYMCZAK; EDUARDO K. LONDERO; EVANDRO A. MEYER; MÁRCIO C. NAVROSKI

    2017-01-01

    ABSTRACT There is a huge lack of researches that evaluate the nutritional limits in tree species used in urban forestry, especially in terms of micronutrients. This study aimed to establish limits and range of micronutrients levels for the proper development of tree species utilized in urban forestry. The study was conducted in the city of Santa Maria-RS-Brazil. Through forest inventory, 23 forest species present in urban forest were selected, and 05 vegetative branches of each tree were coll...

  2. Tree-Species Classification in Subtropical Forests Using Airborne Hyperspectral and LiDAR Data

    OpenAIRE

    Xin Shen; Lin Cao

    2017-01-01

    Accurate classification of tree-species is essential for sustainably managing forest resources and effectively monitoring species diversity. In this study, we used simultaneously acquired hyperspectral and LiDAR data from LiCHy (Hyperspectral, LiDAR and CCD) airborne system to classify tree-species in subtropical forests of southeast China. First, each individual tree crown was extracted using the LiDAR data by a point cloud segmentation algorithm (PCS) and the sunlit portion of each crown wa...

  3. Household Tree Planting in Tigrai, Northern Ethiopia: Tree Species, Purposes, and Determinants

    OpenAIRE

    Gebreegziabher, Zenebe; Mekonnen, Alemu; Kassie, Menale; Köhlin, Gunnar

    2010-01-01

    Trees have multiple purposes in rural Ethiopia, providing significant economic and ecological benefits. Planting trees supplies rural households with wood products for their own consumption, as well for sale, and decreases soil degradation. We used cross-sectional household-level data to analyze the determinants of household tree planting and explored the most important tree attributes or purpose(s) that enhance the propensity to plant trees. We set up a sample selection framework that simult...

  4. Molecular phylogenetics, systematics and host-plant associations of the Bruchidius albosparsus (Fåhraeus) species group (Coleoptera, Chrysomelidae, Bruchinae) with the description of four new species.

    Science.gov (United States)

    Delobel, Alex; Le Ru, Bruno; Genson, Gwenaëlle; Musyoka, Boaz K; Kergoat, Gael J

    2015-03-16

    Bruchidius Schilsky is a large paraphyletic genus of seed beetles (Coleoptera: Chrysomelidae: Bruchinae) which consists of multiple lineages that are usually associated with narrow sets of host-plants. In this study we focus on a group that mostly develops on wattle trees (acacias) belonging to the genus Vachellia Wight & Arn. This group originally included nine species and was designated as the Bruchidius centromaculatus (Allard) species group, but recent phylogenetic analyses revealed that these species belong to a much wider group of species with similar morphologies. For reasons of anteriority we call this enlarged group Bruchidius albosparsus (Fåhraeus). Here we review the morphology of species in this group and provide new diagnoses and ecological data for 10 species. The following combinations and synonymies are proposed: Bruchidius tanaensis (Pic, 1921) (= Bruchus tanaensis Pic, 1921) comb. nov. and Bruchidius albosparsus (Fåhraeus, 1839) (= Bruchus spadiceus Fåhraeus, 1839) syn. nov. Four new species are also described: B. eminingensis sp. nov., B. gerrardiicola sp. nov., B. glomeratus sp. nov. and B. haladai sp. nov. Finally we carried out molecular phylogenetic analyses on a multi-marker dataset of 59 specimens and 35 species, including 14 species from the group. The resulting trees allow us to confirm the monophyly of the group of interest and provide a more detailed picture of their evolutionary relationships.

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

    Directory of Open Access Journals (Sweden)

    Alfred Ossai Onefeli

    2015-11-01

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

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

    Science.gov (United States)

    Menyailo, O.; Matvienko, A.

    2012-12-01

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

  7. Multispecies Biofilms and Host Responses: “Discriminating the Trees from the Forest”

    Science.gov (United States)

    Peyyala, R.; Ebersole, J.L.

    2014-01-01

    Periodontal diseases reflect a tissue destructive process of the hard and soft tissues of the periodontium that are initiated by the accumulation of multispecies bacterial biofilms in the subgingival sulcus. This accumulation, in both quantity and quality of bacteria, results in a chronic immunoinflammatory response of the host to control this noxious challenge, leading to collateral damage of the tissues. As knowledge of the characteristics of the host-bacterial interactions in the oral cavity has expanded, new knowledge has become available on the complexity of the microbial challenge and the repertoire of host responses to this challenge. Recent results from the Human Microbiome Project continue to extend the array of taxa, genera, and species of bacteria that inhabit the multiple niches in the oral cavity; however, there is rather sparse information regarding variations in how host cells discriminate commensal from pathogenic species, as well as how the host response is affected by the 3-dimensional architecture and interbacterial interactions that occur in the oral biofilms. This review provides some insights into thes- processes by including existing literature on the biology of nonoral bacterial biofilms, and the more recent literature just beginning to document how the oral cavity responds to multispecies biofilms. PMID:23141757

  8. Tree response to bark harvest: the case of a medicinal species ...

    African Journals Online (AJOL)

    Tree response to bark harvest: the case of a medicinal species, Garcinia lucida , as source of raw materials for plant-based drug development. ... on trees, from which bark was hardly removed from wood during harvest, probably characterized physiologically by a downward sap flow due to poor water supply in trees.

  9. Tree species identity and functional traits but not species richness affect interrill erosion processes in young subtropical forests

    Science.gov (United States)

    Seitz, S.; Goebes, P.; Song, Z.; Bruelheide, H.; Härdtle, W.; Kühn, P.; Li, Y.; Scholten, T.

    2015-06-01

    Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale runoff plots was conducted to investigate the influence of tree species richness and identity as well as tree functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 t ha-1 a-1 was calculated. This study provided evidence that different tree species affect interrill erosion, but higher tree species richness did not mitigate soil losses in young forest stands. Thus, different tree morphologies have to be considered, when assessing erosion under forest. High crown cover and leaf area index reduced soil losses in initial forest ecosystems, whereas rising tree height increased them. Even if a leaf litter cover was not present, remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on soil loss. Long-term monitoring of soil erosion under closing tree canopies is necessary and a wide range of functional tree traits should be taken into consideration in future research.

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

    Science.gov (United States)

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

    2015-03-15

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

  11. Accuracy of tree grade projections for five Appalachian hardwood species

    Science.gov (United States)

    Gary W. Miller; Aaron T. Graves; Kurt W. Gottschalk; John E. Baumgras

    2008-01-01

    The potential value increase of individual trees is an important factor in planning effective forest management strategies. Similar to other investments, trees with high potential value increase are retained and allowed to grow, and those with relatively low potential value increase are harvested so that the proceeds may earn a higher rate of return elsewhere. Tree...

  12. Plasmodium prevalence across avian host species is positively associated with exposure to mosquito vectors.

    Science.gov (United States)

    Medeiros, Matthew C I; Ricklefs, Robert E; Brawn, Jeffrey D; Hamer, Gabriel L

    2015-11-01

    The prevalence of vector-borne parasites varies greatly across host species, and this heterogeneity has been used to relate infectious disease susceptibility to host species traits. However, a few empirical studies have directly associated vector-borne parasite prevalence with exposure to vectors across hosts. Here, we use DNA sequencing of blood meals to estimate utilization of different avian host species by Culex mosquitoes, and relate utilization by these malaria vectors to avian Plasmodium prevalence. We found that avian host species that are highly utilized as hosts by avian malaria vectors are significantly more likely to have Plasmodium infections. However, the effect was not consistent among individual Plasmodium taxa. Exposure to vector bites may therefore influence the relative number of all avian Plasmodium infections among host species, while other processes, such as parasite competition and host-parasite coevolution, delimit the host distributions of individual Plasmodium species. We demonstrate that links between avian malaria susceptibility and host traits can be conditioned by patterns of exposure to vectors. Linking vector utilization rates to host traits may be a key area of future research to understand mechanisms that produce variation in the prevalence of vector-borne pathogens among host species.

  13. Zoospore chemotaxis of closely related legume‐root infecting Phytophthora species towards host isoflavones

    National Research Council Canada - National Science Library

    Hosseini, S; Heyman, F; Olsson, U; Broberg, A; Funck Jensen, D; Karlsson, M

    2014-01-01

    .... Phytophthora niederhauserii is considered to have a broad host range. Zoospores of some P hytophthora species are chemotactically attracted to the isoflavones that are secreted by their host plants...

  14. Species Tree Estimation for the Late Blight Pathogen, Phytophthora infestans, and Close Relatives

    Science.gov (United States)

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

    2012-01-01

    To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based “supergene” approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred. PMID:22615869

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

    Science.gov (United States)

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

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

  16. Tree Species Diversity and Population Structure in the Tropical Forests of North Central Eastern Ghats, India

    Directory of Open Access Journals (Sweden)

    Dumpa PREMAVANI

    2014-12-01

    Full Text Available The tree species diversity and population structure were studied in four stands of the tropical forests in the north-central Eastern Ghats, based on tree inventories conducted on four 1-ha plots. In the four independent plots, two 5 x 1000 m transects were established and all trees with ≥ 15 cm girth at breast height were enumerated. The density, frequency, basal area and IVI along with diversity indices viz. Shannon index, species richness, equitability and species dominance were computed to see the variation in tree community. A total of 92 species representing 73 genera under 40 families of angiosperms were recorded. Tree species richness was as low as 34 species per hectare plot in Geddapalli to as high as 48 species in Koruturu. Tree density ranged from 360 stems per hectare in plot Geddapalli to 526 stems in plot Chintapalli and that of total basal area from 16.31 m2 ha-1 in Koruturu to 31.15 m2 ha-1 in Chintapalli. The number of species and stems decreased from the smaller to the largest girth classes. The tree inventories of the study area when compared to those of the other tropical forests showed great differences in density and basal area. This may probably be due to differences in geography and annual rainfall patterns. The information on tree species structure and function can provide baseline information for conservation of the biodiversity.

  17. To include or not to include: The Impact of Gene Filtering on Species Tree Estimation Methods.

    Science.gov (United States)

    Molloy, Erin K; Warnow, Tandy

    2017-09-15

    With the increasing availability of whole genome data, many species trees are being constructed from hundreds to thousands of loci. Although concatenation analysis using maximum likelihood is a standard approach for estimating species trees, it does not account for gene tree heterogeneity, which can occur due to many biological processes, such as incomplete lineage sorting. Coalescent species tree estimation methods, many of which are statistically consistent in the presence of incomplete lineage sorting, include Bayesian methods that co-estimate the gene trees and the species tree, summary methods that compute the species tree by combining estimated gene trees, and site-based methods that infer the species tree from site patterns in the alignments of different loci. Due to concerns that poor quality loci will reduce the accuracy of estimated species trees, many recent phylogenomic studies have removed or filtered genes on the basis of phylogenetic signal and/or missing data prior to inferring species trees; little is known about the performance of species tree estimation methods when gene filtering is performed.We examine how incomplete lineage sorting, phylogenetic signal of individual loci, and missing data affect the absolute and the relative accuracy of species tree estimation methods and show how these properties affect methods' responses to gene filtering strategies. In particular, summary methods (ASTRAL-II, ASTRID, and MP-EST), a site-based coalescent method (SVDquartets within PAUP*), and an unpartitioned concatenation analysis using maximum likelihood (RAxML) were evaluated on a heterogeneous collection of simulated multi-locus datasets, and the following trends were observed. Filtering genes based on gene tree estimation error improved the accuracy of the summary methods when levels of incomplete lineage sorting were low to moderate but did not benefit the summary methods under higher levels of incomplete lineage sorting, unless gene tree estimation

  18. Screening of Tree Species for Improving Outdoor Human Thermal Comfort in a Taiwanese City

    Directory of Open Access Journals (Sweden)

    Yu-Hao Lin

    2017-02-01

    Full Text Available Tropical cities can use urban greening designs featuring trees that provide shade and cooling in hot outdoor environments. The cooling effect involves numerous tree characteristics that are not easy to control during planting design, such as the canopy size and the optical properties of leaves. Planting the appropriate tree species dominates the cooling effects and the human thermal environment. Based on environmental and plant data, including the tree species, crown diameter of trees, physiologically equivalent temperature (PET, and sky view factor (SVF in an outdoor space, a series of hierarchical cluster analysis (HCA procedures was implemented to identify the tree species that are appropriate for improving thermal comfort. The results indicated strong correlations between SVF, average crown diameter, and PET. SVF decreased as the average crown diameter increased. For the average crown diameter of trees in an area wider than 1.5 m, the cooling effect was especially dominated by the tree species. Therefore, 15 species were screened by HCA procedures, based on a similar cooling effect. These species had various cooling effects, and were divided into four categories. Tree species, such as Spathodea campanulata and Cinnamomum camphora, had the appropriate crown diameter and cooling effect for the most comfortable thermal environment.

  19. Species richness and resource availability: a phylogenetic analysis of insects associated with trees.

    Science.gov (United States)

    Kelly, C K; Southwood, T R

    1999-07-06

    The data on the number of species of insects associated with various trees in Britain have been reanalyzed to factor out possible bias from phylogenetic effects. It was found that tree availability (range and abundance) continues to provide a good predictor (r = 0. 852) of insect-species richness, slightly better than straightforward cross-species analyses. Of the two components of tree availability, tree abundance gives a much better prediction than tree range. The species richness on trees of major taxa with similar trophic habits (Lepidoptera and Hymenoptera/Symphyta and the two suborders of the Homoptera-Auchenorrhyncha and Sternorrhyncha) shows positive correlations; there is thus no evidence of competitive exclusion at this taxonomic level.

  20. Host species and developmental stage, but not host social structure, affects bacterial community structure in socially polymorphic bees.

    Science.gov (United States)

    McFrederick, Quinn S; Wcislo, William T; Hout, Michael C; Mueller, Ulrich G

    2014-05-01

    Social transmission and host developmental stage are thought to profoundly affect the structure of bacterial communities associated with honey bees and bumble bees, but these ideas have not been explored in other bee species. The halictid bees Megalopta centralis and M. genalis exhibit intrapopulation social polymorphism, which we exploit to test whether bacterial communities differ by host social structure, developmental stage, or host species. We collected social and solitary Megalopta nests and sampled bees and nest contents from all stages of host development. To survey these bacterial communities, we used 16S rRNA gene 454 pyrosequencing. We found no effect of social structure, but found differences by host species and developmental stage. Wolbachia prevalence differed between the two host species. Bacterial communities associated with different developmental stages appeared to be driven by environmentally acquired bacteria. A Lactobacillus kunkeei clade bacterium that is consistently associated with other bee species was dominant in pollen provisions and larval samples, but less abundant in mature larvae and pupae. Foraging adults appeared to often reacquire L. kunkeei clade bacteria, likely while foraging at flowers. Environmental transmission appears to be more important than social transmission for Megalopta bees at the cusp between social and solitary behavior. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Balwant KUMAR

    2012-06-01

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

  2. Overstory treatment and planting season affect survival of replacement tree species in emerald ash borer threatened Fraxinus nigra forests in Minnesota, USA

    Science.gov (United States)

    Christopher E. Looney; Anthony W. D' Amato; Brian J. Palik; Robert A. Slesak

    2015-01-01

    Fraxinus nigra Marsh. (black ash) wetland forests in northern Minnesota, USA, are threatened by the invasive insect, emerald ash borer (Agrilus planipennis Fairmaire (EAB)). A potential management option is promoting regeneration of tree species that are not EAB hosts to maintain ecosystem functions. Using an operational-scale...

  3. Analysis of growth trend changes for 51 temperate tree species using Korea national forest inventory data

    Science.gov (United States)

    Park, M.; Moon, M.; Park, J.; Cho, S.; Kim, H. S.

    2016-12-01

    Individual tree growth rates can be affected by various factors such as species, soil fertility, stand development stage, disturbance, and climate etc. To estimate the effect of changes in tree growth rate on the structure and functionality of forest ecosystem in the future, we analyzed the change of species-specific growth trends using the fifth Korea national forest inventory data, which was collected from 2006 to 2010. The ring samples of average tree were collected from nationwide inventory plots and the total number of individual tree ring series was 69,128 covering 185 tree species. Among those, fifty one species with more than 100 tree ring series were used for our analysis. For growth-trend analysis, standardized regional curves of individual species growth were generated from three forest zone in South Korea; subarctic, cool temperate, warm temperate forest zone. Then individual tree ring series was indexed by dividing the growth of the tree by expected growth from standardized regional curves. Then the ratio of all tree ring series were aligned by year and the Spearman's correlation coefficient of each species was calculated. The results show that most of species had increasing growth rates as forests developed after Korean war. For the last thirty years, 67.3% of species including Quercus spp. and Zelkova serrata had positive growth trends, on the other hand, 11.5% of species including Pinus spp. showed negative growth trends probably due to the changes in successional stages in Korean forests and climate change. These trends also vary with climate zone and species. For examples, Pinus densiflora, which showed negative growth trend overall, had steep negative growth trends in boreal and temperate zone, whereas it showed no specific trend in sub-tropical climate zone. Our trend analysis on 51 temperate tree species growth will be essential to predict the temperate forests species change for the this century.

  4. Landscape variation in tree species richness in northern Iran forests.

    Directory of Open Access Journals (Sweden)

    Charles P-A Bourque

    Full Text Available Mapping landscape variation in tree species richness (SR is essential to the long term management and conservation of forest ecosystems. The current study examines the prospect of mapping field assessments of SR in a high-elevation, deciduous forest in northern Iran as a function of 16 biophysical variables representative of the area's unique physiography, including topography and coastal placement, biophysical environment, and forests. Basic to this study is the development of moderate-resolution biophysical surfaces and associated plot-estimates for 202 permanent sampling plots. The biophysical variables include: (i three topographic variables generated directly from the area's digital terrain model; (ii four ecophysiologically-relevant variables derived from process models or from first principles; and (iii seven variables of Landsat-8-acquired surface reflectance and two, of surface radiance. With symbolic regression, it was shown that only four of the 16 variables were needed to explain 85% of observed plot-level variation in SR (i.e., wind velocity, surface reflectance of blue light, and topographic wetness indices representative of soil water content, yielding mean-absolute and root-mean-squared error of 0.50 and 0.78, respectively. Overall, localised calculations of wind velocity and surface reflectance of blue light explained about 63% of observed variation in SR, with wind velocity accounting for 51% of that variation. The remaining 22% was explained by linear combinations of soil-water-related topographic indices and associated thresholds. In general, SR and diversity tended to be greatest for plots dominated by Carpinus betulus (involving ≥ 33% of all trees in a plot, than by Fagus orientalis (median difference of one species. This study provides a significant step towards describing landscape variation in SR as a function of modelled and satellite-based information and symbolic regression. Methods in this study are sufficiently

  5. Resprouting from roots in four Brazilian tree species

    Directory of Open Access Journals (Sweden)

    Adriana Hissae Hayashi

    2009-09-01

    Full Text Available 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

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  7. Quantitative metrics for assessing predicted climate change pressure on North American tree species

    Science.gov (United States)

    Kevin M. Potter; William W. Hargrove

    2013-01-01

    Changing climate may pose a threat to forest tree species, forcing three potential population-level responses: toleration/adaptation, movement to suitable environmental conditions, or local extirpation. Assessments that prioritize and classify tree species for management and conservation activities in the face of climate change will need to incorporate estimates of the...

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

    DEFF Research Database (Denmark)

    Huang, Weiwei

    and high temperatures on the development of Danish tree species are scarcely investigated. Through a dendroecological approach this dissertation assessed the growth responses related to increment, xylem anatomy and wood property of eight different important tree species, namely Picea abies (L.) Karst...

  9. Species Composition of Down Dead and Standing Live Trees: Implications for Forest Inventory Analysis

    Science.gov (United States)

    Christopher W. Woodall; Linda Nagel

    2005-01-01

    The assessment of species composition in most forest inventory analysis relies solely on standing live tree information characterized by current forest type. With the implementation of the third phase of the U.S. Department of Agriculture Forest Service's Forest Inventory and Analysis program, the species composition of down dead trees, otherwise termed coarse...

  10. Silviculture and the assessment of climate change genetic risk for southern Appalachian forest tree species

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane

    2012-01-01

    Changing climate conditions and increasing insect and pathogen infestations will increase the likelihood that forest trees could experience population-level extirpation or species-level extinction during the next century. Gene conservation and silvicultural efforts to preserve forest tree genetic diversity present a particular challenge in species-rich regions such as...

  11. Fire frequency and tree canopy structure influence plant species diversity in a forest-grassland ecotone

    Science.gov (United States)

    David W. Peterson; Peter B. Reich

    2008-01-01

    Disturbances and environmental heterogeneity are two factors thought to influence plant species diversity, but their effects are still poorly understood in many ecosystems. We surveyed understory vegetation and measured tree canopy cover on permanent plots spanning an experimental fire frequency gradient to test fire frequency and tree canopy effects on plant species...

  12. composition and size class structure of tree species in ihang'ana ...

    African Journals Online (AJOL)

    nb

    R. lucida. R. m ela nop hlo eos. R . vulg aris. P.e xcelsa. N . florib und a. Plant species. D. B. H s ize s. Figure 5: Population structure and DBH size class distribution. (a) The DBH size class distribution for all trees and (b) Average. DBH size classes for the 14 most dominant tree species,. Ihang'ana Forest Reserve, Tanzania.

  13. Endophytic Fungi from Frankincense Tree Improves Host Growth and Produces Extracellular Enzymes and Indole Acetic Acid.

    Directory of Open Access Journals (Sweden)

    Abdul Latif Khan

    Full Text Available Boswellia sacra, an economically important frankincense-producing tree found in the desert woodlands of Oman, is least known for its endophytic fungal diversity and the potential of these fungi to produce extracellular enzymes and auxins. We isolated various fungal endophytes belonging to Eurotiales (11.8%, Chaetomiaceae (17.6%, Incertae sadis (29.5%, Aureobasidiaceae (17.6%, Nectriaceae (5.9% and Sporomiaceae (17.6% from the phylloplane (leaf and caulosphere (stem of the tree. Endophytes were identified using genomic DNA extraction, PCR amplification and sequencing the internal transcribed spacer regions, whereas a detailed phylogenetic analysis of the same gene fragment was made with homologous sequences. The endophytic colonization rate was significantly higher in the leaf (5.33% than the stem (0.262%. The Shannon-Weiner diversity index was H' 0.8729, while Simpson index was higher in the leaf (0.583 than in the stem (0.416. Regarding the endophytic fungi's potential for extracellular enzyme production, fluorogenic 4-methylumbelliferone standards and substrates were used to determine the presence of cellulases, phosphatases and glucosidases in the pure culture. Among fungal strains, Penicillum citrinum BSL17 showed significantly higher amounts of glucosidases (62.15±1.8 μM-1min-1mL and cellulases (62.11±1.6 μM-1min-1mL, whereas Preussia sp. BSL10 showed significantly higher secretion of glucosidases (69.4±0.79 μM-1min-1mL and phosphatases (3.46±0.31μM-1min-1mL compared to other strains. Aureobasidium sp. BSS6 and Preussia sp. BSL10 showed significantly higher potential for indole acetic acid production (tryptophan-dependent and independent pathways. Preussia sp. BSL10 was applied to the host B. sacra tree saplings, which exhibited significant improvements in plant growth parameters and accumulation of photosynthetic pigments. The current study concluded that endophytic microbial resources producing extracellular enzymes and auxin

  14. Endophytic Fungi from Frankincense Tree Improves Host Growth and Produces Extracellular Enzymes and Indole Acetic Acid.

    Science.gov (United States)

    Khan, Abdul Latif; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Al-Farsi, Zainab; Al-Mamari, Aza; Waqas, Muhammad; Asaf, Sajjad; Elyassi, Ali; Mabood, Fazal; Shin, Jae-Ho; Lee, In-Jung

    2016-01-01

    Boswellia sacra, an economically important frankincense-producing tree found in the desert woodlands of Oman, is least known for its endophytic fungal diversity and the potential of these fungi to produce extracellular enzymes and auxins. We isolated various fungal endophytes belonging to Eurotiales (11.8%), Chaetomiaceae (17.6%), Incertae sadis (29.5%), Aureobasidiaceae (17.6%), Nectriaceae (5.9%) and Sporomiaceae (17.6%) from the phylloplane (leaf) and caulosphere (stem) of the tree. Endophytes were identified using genomic DNA extraction, PCR amplification and sequencing the internal transcribed spacer regions, whereas a detailed phylogenetic analysis of the same gene fragment was made with homologous sequences. The endophytic colonization rate was significantly higher in the leaf (5.33%) than the stem (0.262%). The Shannon-Weiner diversity index was H' 0.8729, while Simpson index was higher in the leaf (0.583) than in the stem (0.416). Regarding the endophytic fungi's potential for extracellular enzyme production, fluorogenic 4-methylumbelliferone standards and substrates were used to determine the presence of cellulases, phosphatases and glucosidases in the pure culture. Among fungal strains, Penicillum citrinum BSL17 showed significantly higher amounts of glucosidases (62.15±1.8 μM-1min-1mL) and cellulases (62.11±1.6 μM-1min-1mL), whereas Preussia sp. BSL10 showed significantly higher secretion of glucosidases (69.4±0.79 μM-1min-1mL) and phosphatases (3.46±0.31μM-1min-1mL) compared to other strains. Aureobasidium sp. BSS6 and Preussia sp. BSL10 showed significantly higher potential for indole acetic acid production (tryptophan-dependent and independent pathways). Preussia sp. BSL10 was applied to the host B. sacra tree saplings, which exhibited significant improvements in plant growth parameters and accumulation of photosynthetic pigments. The current study concluded that endophytic microbial resources producing extracellular enzymes and auxin could

  15. Spatial Distribution Patterns in the Very Rare and Species-Rich Picea chihuahuana Tree Community (Mexico)

    Science.gov (United States)

    Wehenkel, Christian; Brazão-Protázio, João Marcelo; Carrillo-Parra, Artemio; Martínez-Guerrero, José Hugo; Crecente-Campo, Felipe

    2015-01-01

    The very rare Mexican Picea chihuahuana tree community covers an area of no more than 300 ha in the Sierra Madre Occidental. This special tree community has been the subject of several studies aimed at learning more about the genetic structure and ecology of the species and the potential effects of climate change. The spatial distribution of trees is a result of many ecological processes and can affect the degree of competition between neighbouring trees, tree density, variability in size and distribution, regeneration, survival, growth, mortality, crown formation and the biological diversity within forest communities. Numerous scale-dependent measures have been established in order to describe spatial forest structure. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. In this study, we examined the spatial distribution pattern of trees in the P. chihuahuana tree community in 12 localities, in relation to i) tree stand density, ii) diameter distribution (vertical structure), iii) tree species diversity, iv) geographical latitude and v) tree dominance at a fine scale (in 0.25 ha plots), with the aim of obtaining a better understanding of the complex ecosystem processes and biological diversity. Because of the strongly mixed nature of this tree community, which often produces low population densities of each tree species and random tree fall gaps caused by tree death, we expect aggregated patterns in individual Picea chihuahuana trees and in the P. chihuahuana tree community, repulsive Picea patterns to other tree species and repulsive patterns of young to adult trees. Each location was represented by one plot of 50 x 50 m (0.25 ha) established in the centre of the tree community. The findings demonstrate that the hypothesis of aggregated tree pattern is not applicable to the mean pattern measured by Clark-Evans index, Uniform Angle index and Mean Directional index of the uneven-aged P

  16. Spatial Distribution Patterns in the Very Rare and Species-Rich Picea chihuahuana Tree Community (Mexico.

    Directory of Open Access Journals (Sweden)

    Christian Wehenkel

    Full Text Available The very rare Mexican Picea chihuahuana tree community covers an area of no more than 300 ha in the Sierra Madre Occidental. This special tree community has been the subject of several studies aimed at learning more about the genetic structure and ecology of the species and the potential effects of climate change. The spatial distribution of trees is a result of many ecological processes and can affect the degree of competition between neighbouring trees, tree density, variability in size and distribution, regeneration, survival, growth, mortality, crown formation and the biological diversity within forest communities. Numerous scale-dependent measures have been established in order to describe spatial forest structure. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. In this study, we examined the spatial distribution pattern of trees in the P. chihuahuana tree community in 12 localities, in relation to i tree stand density, ii diameter distribution (vertical structure, iii tree species diversity, iv geographical latitude and v tree dominance at a fine scale (in 0.25 ha plots, with the aim of obtaining a better understanding of the complex ecosystem processes and biological diversity. Because of the strongly mixed nature of this tree community, which often produces low population densities of each tree species and random tree fall gaps caused by tree death, we expect aggregated patterns in individual Picea chihuahuana trees and in the P. chihuahuana tree community, repulsive Picea patterns to other tree species and repulsive patterns of young to adult trees. Each location was represented by one plot of 50 x 50 m (0.25 ha established in the centre of the tree community. The findings demonstrate that the hypothesis of aggregated tree pattern is not applicable to the mean pattern measured by Clark-Evans index, Uniform Angle index and Mean Directional index of the uneven

  17. Response of tree growth and species coexistence to density and species evenness in a young forest plantation with two competing species

    Science.gov (United States)

    Collet, Catherine; Ningre, François; Barbeito, Ignacio; Arnaud, Anthony; Piboule, Alexandre

    2014-01-01

    Background and Aims There is considerable evidence for the presence of positive species diversity–productivity relationships in plant populations, but the population parameters determining the type and strength of the relationship are poorly defined. Relationships between species evenness and tree survival or species coexistence are not well established. The objective of this study was to quantify the joint effects of density and species evenness on tree productivity and species coexistence. Methods A 12-year-old experimental tree plantation mixing two species according to a double gradient of density and species proportion was used. A neighbourhood approach was employed and descriptors of local competition were used to model individual tree growth. Fagus sylvatica and Acer pseudoplatanus were used as model species, as they can be considered as ecologically equivalent in their young stages. Key Results Density and tree size were primary factors determining individual growth and stand productivity. Species identity had a significant, but less pronounced, role. Stand productivity was highest when species evenness was close to 1 and slightly lower in uneven mixtures. The reduction in stand productivity when species evenness decreased was of similar magnitude irrespective of which species became dominant, indicating symmetric effects for the two species. When examining individual tree growth in response to species proportion for each species separately, it was observed for both species that individual trees exhibited greater growth in uneven mixtures in which the other species was more frequent. Conclusions The results suggest that mixtures of these two functionally similar species have the highest production at maximum evenness, indicating a complementary effect between them. The presence of a mixture combines both stabilizing mechanisms (individuals from both species show higher growth when surrounded by individuals from the other species) and equalizing mechanisms

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

    Science.gov (United States)

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

    2014-01-01

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

  19. Species-specific responses of tree ring and leaf stable isotope signals in isohydric and anisohydric trees to drought

    Science.gov (United States)

    Oh, Y.; Welp, L.; Yi, K.; Maxwell, J. T.; Novick, K. A.

    2016-12-01

    Eastern US forests, like many globally, have experienced a significant increase in temperature and summer drought. Recently, it has been suggested to classify tree's water use strategy in response to drought along the spectrum of isohydric to anisohydric species depending on their leaf-level hydraulic regulation. The differences in water use strategy lead to differences in internal leaf CO2 concentrations (Ci). Changes in Ci from stomatal conductance (gs) response to drought and changes in carbon assimilation rates (A) contribute to the tree's intrinsic water use efficiency (iWUE), which is the ratio of A to gs. Changes in iWUE are recorded in 13C/12C (d13C) ratios of stem wood in annual tree rings. Further information from the 18O/16O ratio (d18O) of wood is hypothesized to qualitatively separate the impact of A or gs using the dual-isotope method (Scheideggar et al. 2000). However, recent studies have questioned the applicability of the dual-isotope approach in cases of severe drought. In this study, we will use 3 years (2011-2013) of bulk leaf samples and tree ring cellulose from three isohydric and two anisohydric species in Morgan-Monroe State Forest to examine how the iWUE of each tree species responds to drought in d13C and d18O. To examine dual-isotope approach applied to tree ring measurements in a mechanistic way, we will compare the temporal changes of bulk leaf isotope measurements and leaf gas exchange measurements from an infrared gas analyzer. We will further use the annual dual-isotope signals in leaves and tree rings to test the coupling between leaf and tree ring signals. We hypothesize that (1) the iWUE of isohydric species will respond more sensitively to the severe drought in 2012 than the anisohydric species, and (2) the dual-isotope approach may be more applicable for isohydric species since isotope signals are mainly controlled by the stomata, not the leaf's complicated downstream process. This study will show that oxygen and carbon isotope

  20. Covariance in species diversity and facilitation among non-interactive parasite taxa: all against the host.

    Science.gov (United States)

    Krasnov, B R; Mouillot, D; Khokhlova, I S; Shenbrot, G I; Poulin, R

    2005-10-01

    Different parasite taxa exploit different host resources and are often unlikely to interact directly. It is unclear, however, whether the diversity of any given parasite taxon is indirectly influenced by that of other parasite taxa on the same host. Some components of host immune defences may operate simultaneously against all kinds of parasites, whereas investment by the host in specific defences against one type of parasite may come at the expense of defence against other parasites. We investigated the relationships between the species diversity of 4 higher taxa of ectoparasites (fleas, sucking lice, mesostigmatid mites, and ixodid ticks), and between the species richness of ectoparasites and endoparasitic helminths, across different species of rodent hosts. Our analyses used 2 measures of species diversity, species richness and taxonomic distinctness, and controlled for the potentially confounding effects of sampling effort and phylogenetic relationships among host species. We found positive pairwise correlations between the species richness of fleas, mites and ticks; however, there was no association between species richness of any of these 3 groups and that of lice. We also found a strong positive relationship between the taxonomic distinctness of ecto- and endoparasite assemblages across host species. These results suggest the existence of a process of apparent facilitation among unrelated taxa in the organization of parasite communities. We propose explanations based on host immune responses, involving acquired cross-resistance to infection and interspecific variation in immunocompetence among hosts, to account for these patterns.

  1. Soil carbon accumulation and nitrogen retention traits of four tree species grown in common gardens

    DEFF Research Database (Denmark)

    Gurmesa, Geshere Abdisa; Schmidt, Inger Kappel; Gundersen, Per

    2013-01-01

    Tree species effects on soil carbon (C) accumulation are uncertain, especially with respect to the mineral soil C, and the consistency of such effects across soil types is not known. The interaction between C accumulation and nitrogen (N) retention among common tree species has also been little...... explored. Effects of four tree species on soil C and N stocks and soil water nitrate concentration below the root zone were evaluated in a common garden design replicated at eight sites in Denmark. The tree species were beech (Fagus sylvatica L.), oak (Quercus robur L.), larch (Larix leptolepis Kaempf...... differed significantly between conifers and broadleaves. The observed differences in forest floor C and N stocks were attributed to differences in litter turnover rates among the tree species. Mineral soil C stocks were significantly higher in stands of Norway spruce than in stands of oak and beech while...

  2. Cophylogeny of the anther smut fungi and their caryophyllaceous hosts: Prevalence of host shifts and importance of delimiting parasite species for inferring cospeciation

    Directory of Open Access Journals (Sweden)

    Yockteng Roxana

    2008-03-01

    Full Text Available Abstract Background Using phylogenetic approaches, the expectation that parallel cladogenesis should occur between parasites and hosts has been validated in some studies, but most others provided evidence for frequent host shifts. Here we examine the evolutionary history of the association between Microbotryum fungi that cause anther smut disease and their Caryophyllaceous hosts. We investigated the congruence between host and parasite phylogenies, inferred cospeciation events and host shifts, and assessed whether geography or plant ecology could have facilitated the putative host shifts identified. For cophylogeny analyses on microorganisms, parasite strains isolated from different host species are generally considered to represent independent evolutionary lineages, often without checking whether some strains actually belong to the same generalist species. Such an approach may mistake intraspecific nodes for speciation events and thus bias the results of cophylogeny analyses if generalist species are found on closely related hosts. A second aim of this study was therefore to evaluate the impact of species delimitation on the inferences of cospeciation. Results We inferred a multiple gene phylogeny of anther smut strains from 21 host plants from several geographic origins, complementing a previous study on the delimitation of fungal species and their host specificities. We also inferred a multi-gene phylogeny of their host plants, and the two phylogenies were compared. A significant level of cospeciation was found when each host species was considered to harbour a specific parasite strain, i.e. when generalist parasite species were not recognized as such. This approach overestimated the frequency of cocladogenesis because individual parasite species capable of infecting multiple host species (i.e. generalists were found on closely related hosts. When generalist parasite species were appropriately delimited and only a single representative of

  3. Analysis of Genetic Variation in Brevipalpus yothersi (Acari: Tenuipalpidae) Populations from Four Species of Citrus Host Plants.

    Science.gov (United States)

    Salinas-Vargas, Delfina; Santillán-Galicia, Ma Teresa; Guzmán-Franco, Ariel W; Hernández-López, Antonio; Ortega-Arenas, Laura D; Mora-Aguilera, Gustavo

    2016-01-01

    We studied species diversity and genetic variation among populations of Brevipalpus mites from four species of citrus host plants. We sampled mites on orange, lime, grapefruit and mandarin trees from orchards at six localities distributed in the five most important citrus producing states in Mexico. Genetic variation among citrus host plants and localities were assessed by analysis of nucleotide sequence data from fragments of the mitochondrial cytochrome oxidase subunit I (COI). Both Brevipalpus yothersi and B. californicus were found at these sites, and B. yothersi was the most abundant species found on all citrus species and in all localities sampled. B. californicus was found mainly on orange and mandarin and only in two of the states sampled. AMOVA and haplotype network analyses revealed no correlation between B. yothersi genetic population structure and geographical origin or citrus host plant species. Considering that a previous study reported greater genetic diversity in B. yothersi populations from Brazil than we observed in Mexico, we discuss the possibility that the Mexican populations may have originated in the southern region of America.

  4. Characterization of bacterial knot disease caused by Pseudomonas savastanoi pv. savastanoi on pomegranate (Punica granatum L.) trees: a new host of the pathogen.

    Science.gov (United States)

    Bozkurt, I A; Soylu, S; Mirik, M; Ulubas Serce, C; Baysal, Ö

    2014-11-01

    This study aimed to isolate and identify the causal organism causing hyperplastic outgrowths (knots) on stems and branches of pomegranate trees in the Eastern Mediterranean region of Turkey. Bacterial colonies were isolated from young knots on plates containing selective nutrient media. Biochemical tests, fatty acid analysis and PCR were performed to identify possible causal disease agent. Representative isolates were identified as Pseudomonas.pv.savastanoi (Psv) using biochemical tests, fatty acid profiling and PCR. Following inoculation of pomegranate plants (cv. hicaz) with bacterial suspensions, 25 of 54 bacterial isolates caused typical knots at the site of inoculation. PCR analysis, using specific primer for Psv, generated a single amplicon from all isolates. The similarity of the sequence of Turkish pomegranate isolate was 99% similar to the corresponding gene sequences of Psv in the databases. Based on symptoms, biochemical, molecular, pathogenicity tests and sequence analyses, the disease agent of knots observed on the pomegranate trees is Psv. To the best of our knowledge, this research has revealed pomegranate as a natural host of Psv, which extends the list of host plant species affected by the pathogen in the world and Turkey. Pomegranate trees were affected by the disease with outgrowths (galls or knot) disease. Currently, there is no published study on disease agent(s) causing the galls or knots on pomegranate trees in worldwide. Bacterial colonies were isolated from young knots. The causal agent of the knot Pseudomonas savastanoi pv.savastanoi (Psv) was identified based on symptoms, biochemical, molecular methods, pathogenicity tests and sequence analysis. To the best of our knowledge, this is the first report of Psv on pomegranate as a natural host, which extends the growing list of plant species affected by this bacterium in the world and Turkey. © 2014 The Society for Applied Microbiology.

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

    Science.gov (United States)

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

    2018-02-01

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

  6. Species-specific effects on throughfall kinetic energy below 12 subtropical tree species are related to leaf traits and tree architecture

    Science.gov (United States)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Kröber, Wenzel; Bruelheide, Helge; Li, Ying; von Oheimb, Goddert; Scholten, Thomas

    2015-04-01

    Soil erosion impacts environmental systems widely, especially in subtropical China where high erosion rates occur. The comprehension about the mechanisms that induce soil erosion on agricultural land is broad, but erosion processes below forests are only rarely understood. Especially throughfall kinetic energy (TKE) is influenced by forests and their structure as well as their succession in many ways. Today, many forests are monoculture tree stands due to economic reasons by providing timber, fuel and pulp wood. Therefore, this study investigates the role of different monoculture forest stands on TKE that were afforestated in 2008. The main questions are: Is TKE species-specific? What are characteristic leaf traits and tree architectural parameters that induce a species-specific effect on TKE and by what extend do they contribute to a mediation of species-specific effects on TKE? We measured TKE of 12 different species in subtropical China using sand-filled splash cups during five rainfall events in summer 2013. In addition, 14 leaf traits and tree architectural parameters were registered to link species-specific effects on TKE to vegetation parameters. Our results show that TKE is highly species-specific. Highest TKE was found below Choerospondias axillaris and Sapindus mukorossi, while Schima superba showed lowest TKE. The latter species can be regarded as key species for reduced erosion occurrence. This species effect is mediated by leaf habit, leaf area, leaf pinnation, leaf margin, tree ground diameter, crown base height, tree height, number of branches and LAI as biotic factors and rainfall amount as abiotic factor. Moreover, leaf habit, tree height and LA show high effect sizes on TKE and can be considered as major drivers evoking TKE differences below vegetation.

  7. Expression differences in Aphidius ervi (Hymenoptera: Braconidae) females reared on different aphid host species.

    Science.gov (United States)

    Ballesteros, Gabriel I; Gadau, Jürgen; Legeai, Fabrice; Gonzalez-Gonzalez, Angelica; Lavandero, Blas; Simon, Jean-Christophe; Figueroa, Christian C

    2017-01-01

    The molecular mechanisms that allow generalist parasitoids to exploit many, often very distinct hosts are practically unknown. The wasp Aphidius ervi, a generalist koinobiont parasitoid of aphids, was introduced from Europe into Chile in the late 1970s to control agriculturally important aphid species. A recent study showed significant differences in host preference and host acceptance (infectivity) depending on the host A. ervi were reared on. In contrast, no genetic differentiation between A. ervi populations parasitizing different aphid species and aphids of the same species reared on different host plants was found in Chile. Additionally, the same study did not find any fitness effects in A. ervi if offspring were reared on a different host as their mothers. Here, we determined the effect of aphid host species (Sitobion avenae versus Acyrthosiphon pisum reared on two different host plants alfalfa and pea) on the transcriptome of adult A. ervi females. We found a large number of differentially expressed genes (between host species: head: 2,765; body: 1,216; within the same aphid host species reared on different host plants: alfalfa versus pea: head 593; body 222). As expected, the transcriptomes from parasitoids reared on the same host species (pea aphid) but originating from different host plants (pea versus alfalfa) were more similar to each other than the transcriptomes of parasitoids reared on a different aphid host and host plant (head: 648 and 1,524 transcripts; body: 566 and 428 transcripts). We found several differentially expressed odorant binding proteins and olfactory receptor proteins in particular, when we compared parasitoids from different host species. Additionally, we found differentially expressed genes involved in neuronal growth and development as well as signaling pathways. These results point towards a significant rewiring of the transcriptome of A. ervi depending on aphid-plant complex where parasitoids develop, even if different biotypes

  8. Complementarity of native and introduced tree species: Exploring ...

    African Journals Online (AJOL)

    Given that access to timber from native trees within the protected area is restricted, management of tree resources outside of the protected area represents a critical nexus between biodiversity conservation and human benefits linked to ecosystem services. We investigated and characterized the local farmer's use of ...

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    diversity when humans reduce tree availability. Hence, woodpeckers exemplify how broad-scale diversity patterns are predominantly shaped by a biotic factor, and how climate and human influence can have indirect effects on animal biodiversity via the effects on tree availability and forest cover....

  10. Identification of indigenous tree and shrub fodder species in the ...

    African Journals Online (AJOL)

    Mo

    Family size averaged about 8 persons, though slightly higher in Wakiso district. Most (88%) respondents were married, while 7% and 5% were widowed and single respectively. Use of indigenous tree fodder by farmers. About 40% of respondents use indigenous tree fodder throughout the year. Livestock farmers in rural ...

  11. Grass species composition, yield and quality under and outside tree ...

    African Journals Online (AJOL)

    A two-year study was conducted in lightly grazed areas of Matopos Research Station, Zimbabwe, to evaluate the impact of widely spaced trees on understorey grass composition, yield and quality. The study trees were Terminalia sericea and Acacia karroo. Ordination techniques using grass density and biomass as indices ...

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

    Science.gov (United States)

    Walthert, Lorenz; Meier, Eliane Seraina

    2017-11-01

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

  13. Tree Species Composition and Regeneration Status of Shitalpur Forest Beat under Chittagong North Forest Division, Bangladesh

    Directory of Open Access Journals (Sweden)

    Asadozzaman Nur

    2016-01-01

    Full Text Available Biodiversity erosion particularly in developing countries is a matter of great concern to the global ecological community. Species composition and regeneration indicate the health of forest. This study explored tree species composition and regeneration of natural hill forest of Shitalpur under Chittagong North Forest Division through 27 sample plots of 20 m × 20 m for trees and 2 m × 2 m for regeneration. A total of 47 tree species belonging to 29 families and 17 regenerating species belonging to 15 families were recorded. The tree stem density, basal area, and wood volume were 0.49 m2/ha, 1425 stem/ha, and 189.9 m3/ha, respectively. Mean regeneration was significantly higher in bottom hill (14374 seedlings/ha compared to top hill (9671 seedlings/ha. Toona ciliata was highest (4444 seedlings/ha at the bottom hill compared to other hill positions. The result shows that only 36% of the tree species (17 out of 47 are regenerating in the study area, meaning majority of the tree species (64% are not getting favorable conditions to regenerate. This might be due to absence of mature tree species as a result of overexploitation by local people. The findings may help in monitoring the species composition changes over time and adopting specific conservation programs for Shitalpur Forest.

  14. Where are you sucking from? Using Stable Isotopes to understand Host Specificity in two Hemiparasitic plants above the tree line in Northern Sweden

    Science.gov (United States)

    Macias Sevde, A. S.

    2012-12-01

    By Alejandro Macias, Erik Hobbie, Ruth Varner, Kaitlyn Steele Hemiparasites are known to suck nutrients from nearby plants but their host specificity is not well understood. Hemiparasites are ecosystem engineers, limiting surrounding plant's growth, and decreasing local biodiversity. To better understand this phenomenon, the host specificities of two hemiparasitic angiosperms, Bartsia alpina , and Pedicularis lapponica were studied above the tree line along an elevational gradient in Sweden. B. alpina specialized in wetter environments, as indicated by their higher δ13C signature, and their growth among Salixsp.Betula nana, Bistorta vivipara, Viola biflora, Geranium sp., and Trollious europaeus. P. lapponica was common in drier, less species rich environments, known as heaths, where B. nana, Empetrum negrum, Phyllodoce coeruela, Vaccinium myrtillus and Vaccinium vitis-idaea are the most common species. P. lapponica had higher foliage δ13C due to its better water-use efficiency in a dry environment. Field survey data and δN15 values of both the foliage of the parasitic plants and their potential hosts were used to determine host specificity. Since the δN15 value of the hemiparasitic plant and its host are similar due to parasitism, it was determined that P. lapponica had a preference for plants with an ericoid mycorrhizal association, such as Vaccinium sp, and E. negrum, but not for the common P. coeruela. This does not support the idea found in the literature that P. lapponica has a preference for grasses. B. alpina was less host specific, associating with non-mycorrhizal, ericoid, and ectomycorhizal plants, such as Carex sp, Vaccinium sp., and S. lapponum. The ectomycorrhizal species, Salix sp., and B. nana, were both potential hosts for B. alpina and P. lapponica due to their presence among them. However, the isotopic data revealed that B. alpina had a preference for Salix sp., and P. lapponica had a preference for B. nana.

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

    Directory of Open Access Journals (Sweden)

    B. I. Choudhury

    2007-01-01

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

  16. The mycorrhizal type governs root exudation and nitrogen uptake of temperate tree species.

    Science.gov (United States)

    Liese, Rebecca; Lübbe, Torben; Albers, Nora W; Meier, Ina C

    2017-11-08

    Even though the two dominant mycorrhizal associations of temperate tree species differentially couple carbon (C) and nitrogen (N) cycles in temperate forests, systematic differences between the biogeochemical cycles of arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree species remain poorly described. A classification according to the mycorrhizal type offers the chance, though, to develop a global frame concept for the prediction of temperate ecosystem responses to environmental change. Focusing on the influence of mycorrhizal types on two key plant processes of biogeochemical cycling (root exudation and N acquisition), we investigated four temperate deciduous tree species per mycorrhizal type in a drought experiment in large mesocosms. We hypothesized that (H1) C loss by root exudation is higher in ECM than in AM trees, (H2) drought leads to higher reductions in root exudation of drought-sensitive ECM trees and (H3) inorganic N uptake is higher in AM than in ECM trees. In contradiction to H2, we found no systematic difference in root exudation between the mycorrhizal types at ample soil moisture, but almost twofold higher exudation in ECM trees when exposed to soil drought. In addition, photosynthetic C cost of root exudation strongly increased by ~10-fold in drought-treated ECM trees, while it only doubled in AM trees, which confirms H1. With respect to H3, we corroborated that AM trees had higher absolute and relative inorganic N acquisition rates than ECM trees, while the organic N uptake did not differ between mycorrhizal types. We conclude that ECM trees are less efficient in inorganic N uptake than AM trees, but ECM trees increase root C release as an adaptive response to dry soil to maintain hydraulic conductivity and/or nutrient availability. These systematic differences in key biogeochemical processes support hints on the key role of the mycorrhizal types in coupling C and N cycles in temperate forests. © The Author 2017. Published by Oxford

  17. Gene pool of less widely spread fruit tree species

    Directory of Open Access Journals (Sweden)

    Vojtěch Řezníček

    2004-01-01

    Full Text Available Within the gene pool collected at the Department of Breeding and Propagation of Garden Plants of the Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, in Lednice we established experimental plots with some selected less known tree species - quince (Cydonia oblonga Mill., sea buckthorn (Hippophäe rhamnoides L., Cornelian cherry (Cornus mas L. and honeysuckle (Lonicera caerulea subsp. edulis Turcy. ex Freyn.. The experimental plots were established in successive steps according to the availability of planting material and using conventional methods of cultivation. Evaluations are focused on selected growth parameters, phenology and commercial use of the fruit.The evaluations of the crown of quince showed differences in the size and shape. The variety Hemus had the largest crown volume (5.70 m3; the variety Blanár gave the highest harvest yields. The sea buckthorn varieties Polmix, Dar Katuni and Novosť Altaja produced the longest increments. The average weight of the fruit of the variety Leicora was 0.74 g. The varieties of Cornelian cherry also differed in the growth parameters; the highest shrubs were those of the variety Vyšegorodskij, which also produced the largest fruit – the average weight of the fruit was 4.85 g. The initial growth of selected varieties and genotypes of honeysuckle is different when compared to the fruit-bearing shrubs. Harvest data are in direct proportion to the size of the shrub. Fruit harvest began in mid-May and vegetation ended on 15 October.

  18. Role of Armillaria species on tree dying in Turkey oak and Hungarian oak forest in Lipovica

    Directory of Open Access Journals (Sweden)

    Keča Nenad

    2006-01-01

    Full Text Available The species and population structure of Armillaria species were studied in Turkey oak and Hungarian oak forest. Two species were observed, Armillaria gallica and A. mellea. Armillaria mellea was found on only one tree, and A. gallica was found on seven trees. Four gewets of A. gallica were observed of which two were represented only by one isolate each, while two covered the area of 5 and 9 areas respectively.

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

    Science.gov (United States)

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

    2009-12-01

    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.

  20. LVTree Viewer: An Interactive Display for the All-Species Living Tree Incorporating Automatic Comparison with Prokaryotic Systematics.

    Science.gov (United States)

    Zuo, Guanghong; Zhi, Xiaoyang; Xu, Zhao; Hao, Bailin

    2016-04-01

    We describe an interactive viewer for the All-Species Living Tree (LVTree). The viewer incorporates treeing and lineage information from the ARB-SILVA website. It allows collapsing the tree branches at different taxonomic ranks and expanding the collapsed branches as well, keeping the overall topology of the tree unchanged. It also enables the user to observe the consequence of trial lineage modifications by re-collapsing the tree. The system reports taxon statistics at all ranks automatically after each collapsing and re-collapsing. These features greatly facilitate the comparison of the 16S rRNA sequence phylogeny with prokaryotic taxonomy in a taxon by taxon manner. In view of the fact that the present prokaryotic systematics is largely based on 16S rRNA sequence analysis, the current viewer may help reveal discrepancies between phylogeny and taxonomy. As an application, we show that in the latest release of LVTree, based on 11,939 rRNA sequences, as few as 24 lineage modifications are enough to bring all but two phyla (Proteobacteria and Firmicutes) to monophyletic clusters. Copyright © 2016 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

  1. Tree mortality after synchronized forest insect outbreaks: effects of tree species, bole diameter, and cutting history

    Science.gov (United States)

    Tracey N. Johnson; Steven W. Buskirk; Gregory D. Hayward; Martin G. Raphael

    2014-01-01

    A recent series of bark beetle outbreaks in the Rocky Mountain region of the U.S. is the largest and most intense ever recorded. Factors contributing to tree mortality from bark beetles are complex, but include aspects of forest stand condition. Because stand conditions respond to forest management, evaluating bark beetle-caused tree mortality and changes in forest...

  2. From natural forest to tree crops, co-domestication of forests and tree species: an overview.

    NARCIS (Netherlands)

    Wiersum, K.F.

    1997-01-01

    The process of domestication of tree crops has only been given limited attention. This process starts with the protection of natural forests and ends with the cultivation of domesticated tree crops. In this evolutionary process three types of human-influenced forest environments may be

  3. Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize

    OpenAIRE

    Jordaan, Elizabeth M.; De Waele, D.

    1988-01-01

    The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae inf...

  4. Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) use of Opuntia host species in Argentina

    Science.gov (United States)

    A central aspect in biology and ecology is to determine the combination of factors that influence the distribution of species. In the case of herbivorous insects, the distribution of herbivorous species is necessarily associated with their host plants, a pattern often referred to as “host use”. Nove...

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

    Science.gov (United States)

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

    2018-01-01

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

  6. Gene expression plasticity across hosts of an invasive scale insect species

    DEFF Research Database (Denmark)

    Christodoulides, Nicholas; Van Dam, Alex; Peterson, Daniel A.

    2017-01-01

    For plant-eating insects, we still have only a nascent understanding of the genetic basis of host-use promiscuity. Here, to improve that situation, we investigated host-induced gene expression plasticity in the invasive lobate lac scale insect, Paratachardina pseudolobata (Hemiptera: Keriidae). We...... of several recently published studies of other plant-eating insect species. Thus, across plant-eating insect species, there may be a common set of gene expression changes that enable host-use promiscuity....

  7. Biotic mortality factors affecting emerald ash borer (Agrilus planipennis) are highly dependent on life stage and host tree crown condition

    Science.gov (United States)

    Emerald ash borer (EAB), Agrilus planipennis, is a serious invasive forest pest in North America responsible for killing tens to hundreds of millions of ash trees since it was accidentally introduced in the 1990’s. Although host plant resistance and natural enemies are known to be important sources ...

  8. Tree species functional group is a more important driver of soil properties than tree species diversity across major European forest types

    Science.gov (United States)

    Vesterdal, Lars; Muhie Dawud, Seid; Raulund-Rasmussen, Karsten; Finér, Leena; Domisch, Timo; Ratcliffe, Sophia

    2017-04-01

    The influence of tree species diversity and functional group on soil properties (carbon stock, pH and C/N ratio) has not been explored across major European forest types. We evaluated the relative importance of tree species diversity and functional group on soil carbon (C) stocks, C/N ratio and pH in major European forest types in the six regions Finland, Poland, Germany, Romania, Italy and Spain. We sampled soils in 209 permanent plots along a species diversity gradient from monocultures to 5-species mixtures in the exploratory platform of the FunDivEurope project. Carbon stocks in the topsoil (forest floor (FF), 0-10 cm, and FF+0-10 cm) were positively, but weakly, related to diversity across the regions. While the C/N ratio in the FF+0-10 cm layer decreased significantly with increasing diversity in the Spanish region, pH was unrelated to species diversity across the regions. Tree species functional group (conifer proportion) explained a larger proportion of the variability in soil properties than species diversity. Conifer admixture increased C stock and C/N ratio, and decreased pH, but the impacts differed between the regions for some soil layers. Differences in mean annual temperature, actual evapotranspiration and soil texture between the regions were possible driving factors behind the different functional group effects in Finland, Spain and Germany. The results suggest that targeted selection of tree species with desired characteristics, e.g. complementary traits for resource use, is a preferred management approach for influencing soil C stock, C/N ratio and pH in mixed forests rather than increasing tree species diversity per se.

  9. Designing mixed species tree plantations for the tropics: balancing ecological attributes of species with landholder preferences in the Philippines.

    Science.gov (United States)

    Nguyen, Huong; Lamb, David; Herbohn, John; Firn, Jennifer

    2014-01-01

    A mixed species reforestation program known as the Rainforestation Farming system was undertaken in the Philippines to develop forms of farm forestry more suitable for smallholders than the simple monocultural plantations commonly used then. In this study, we describe the subsequent changes in stand structure and floristic composition of these plantations in order to learn from the experience and develop improved prescriptions for reforestation systems likely to be attractive to smallholders. We investigated stands aged from 6 to 11 years old on three successive occasions over a 6 year period. We found the number of species originally present in the plots as trees >5 cm dbh decreased from an initial total of 76 species to 65 species at the end of study period. But, at the same time, some new species reached the size class threshold and were recruited into the canopy layer. There was a substantial decline in tree density from an estimated stocking of about 5000 trees per ha at the time of planting to 1380 trees per ha at the time of the first measurement; the density declined by a further 4.9% per year. Changes in composition and stand structure were indicated by a marked shift in the Importance Value Index of species. Over six years, shade-intolerant species became less important and the native shade-tolerant species (often Dipterocarps) increased in importance. Based on how the Rainforestation Farming plantations developed in these early years, we suggest that mixed-species plantations elsewhere in the humid tropics should be around 1000 trees per ha or less, that the proportion of fast growing (and hence early maturing) trees should be about 30-40% of this initial density and that any fruit tree component should only be planted on the plantation margin where more light and space are available for crowns to develop.

  10. Powdery mildew of Chrysanthemum × morifolium: phylogeny and taxonomy in the context of Golovinomyces species on Asteraceae hosts.

    Science.gov (United States)

    Bradshaw, Michael; Braun, Uwe; Götz, Monika; Meeboon, Jamjan; Takamatsu, Susumu

    2017-01-01

    The taxonomic history of the common powdery mildew of Chrysanthemum × morifolium (chrysanthemum, florist's daisy), originally described in Germany as Oidium chrysanthemi, is discussed. The position of O. chrysanthemi was investigated on the basis of morphological traits and molecular phylogenetic analyses. Based on the results of this study, this species, which is closely related to Golovinomyces artemisae, was reassessed and reallocated to Golovinomyces. The phylogenetic analysis and taxonomic reassessment of the chrysanthemum powdery mildew is supplemented by a morphological description, a summary of its worldwide distribution data, and a brief discussion of the introduction of this fungus to North America. G. chrysanthemi differs from true G. artemisiae in that it has much longer conidiophores, is not constricted at the base, and has much larger and most importantly longer conidia. The close affinity of Golovinomyces to Artemisia and Chrysanthemum species signifies a coevolutionary event between the powdery mildews concerned and their host species in the subtribe Artemisiinae (Asteraceae tribe Anthemideae). This conclusion is fully supported by the current phylogeny and taxonomy of the host plant genera and the coevolution that occurred with the host and pathogen. The following powdery mildew species, which are associated with hosts belonging to the tribe Anthemideae of the Asteraceae, are epitypified: Alphitomorpha depressa β artemisiae (≡ Alphitomorpha artemisiae), Erysiphe artemisiae, and Oidium chrysanthemi. Erysiphe macrocarpa is neotypified. Their sequences were retrieved from the epitype collections and have been added to the phylogenetic tree. Golovinomyces orontii, an additional powdery mildew species on Chrysanthemum ×morifolium, is reported. This species is rarely found as a spontaneous infection and was obtained from inoculation experiments.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    We explored tree species diversity effects on soil C stock, C/N ratio, and pH as compared with effects of tree species identity. We sampled forest floors and mineral soil (0–40 cm) in a diversity gradient of 1–5 tree species composed of conifers and broadleaves in Białowieża Forest, Poland...

  12. Conspecific Plant-Soil Feedbacks of Temperate Tree Species in the Southern Appalachians, USA

    Science.gov (United States)

    Reinhart, Kurt O.; Johnson, Daniel; Clay, Keith

    2012-01-01

    Many tree species have seedling recruitment patterns suggesting that they are affected by non-competitive distance-dependent sources of mortality. We conducted an experiment, with landscape-level replication, to identify cases of negative distance-dependent effects and whether variation in these effects corresponded with tree recruitment patterns in the southern Appalachian Mountains region. Specifically, soil was collected from 14 sites and used as inocula in a 62 day growth chamber experiment determining whether tree seedling growth was less when interacting with soil from conspecific (like) than heterospecific (other) tree species. Tests were performed on six tree species. Three of the tree species had been previously described as having greater recruitment around conspecifics (i.e. facilitator species group) compared to the other half (i.e. inhibitor species group). We were then able to determine whether variation in negative distance-dependent effects corresponded with recruitment patterns in the field. Across the six species, none were negatively affected by soil inocula from conspecific relative to heterospecific sources. Most species (four of six) were unaffected by soil source. Two species (Prunus serotina and Tsuga canadensis) had enhanced growth in pots inoculated with soil from conspecific trees vs. heterospecifics. Species varied in their susceptibility to soil pathogens, but trends across all species revealed that species classified as inhibitors were not more negatively affected by conspecific than heterospecific soil inocula or more susceptible to pathogenic effects than facilitators. Although plant-soil biota interactions may be important for individual species and sites, it may be difficult to scale these interactions over space or levels of ecological organization. Generalizing the importance of plant-soil feedbacks or other factors across regional scales may be especially problematic for hyperdiverse temperate forests where interactions may be

  13. Characterization of Rosaceae tree species in a young Turkey oak-dominated coppice forest

    Directory of Open Access Journals (Sweden)

    Giulietti V

    2009-09-01

    Full Text Available First results of a trial carried out in an experimental area (“Comunità Montana Colline Metallifere”, Tuscany. After coppicing (winter 1998-1999, 77 Sorbus torminalis, Sorbus domestica and others valuable tree species were released on the whole of 220 standard trees per hectare. Aim of the present study was to estimate the opportunity to produce valuable timber from standards of sporadic tree species living into coppice forests. A research trial aimed at evaluating stem and crown quality as well as radial growth of standards after coppicing was carried out in an area 3 hectares wide. Wild service tree, Service tree and Turkey oak trees were analysed. Seven years after coppicing, the growth pattern of the different species, was also analysed by means of two structural transects. In the early phase after coppicing, root and stump suckers of both Sorbus species (especially Service tree are able to compete with Turkey oak sprouts as for height growth. In the following stage, the social regression of Sorbus trees is easily foreseeible because of the high competitive ability of Quercus. The good stem and crown shaping showed to be characters owned by a few Sorbus standards only. These were characterized as the largest-sized and early well-crown shaped trees. The same trees showed the highest dbh growth and developed few epicormic branches. A better targeted selection rule of valuable timber tree species to build up the standards’ stock is the recommended practice to improve forest biodiversity, as well as to create an economically important additional option to firewood, usually produced in these coppice forests.

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

    Science.gov (United States)

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

    2016-02-01

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

  15. Coordination between water transport capacity, biomass growth, metabolic scaling and species stature in co-occurring shrub and tree species.

    Science.gov (United States)

    Smith, Duncan D; Sperry, John S

    2014-12-01

    The significance of xylem function and metabolic scaling theory begins from the idea that water transport is strongly coupled to growth rate. At the same time, coordination of water transport and growth seemingly should differ between plant functional types. We evaluated the relationships between water transport, growth and species stature in six species of co-occurring trees and shrubs. Within species, a strong proportionality between plant hydraulic conductance (K), sap flow (Q) and shoot biomass growth (G) was generally supported. Across species, however, trees grew more for a given K or Q than shrubs, indicating greater growth-based water-use efficiency (WUE) in trees. Trees also showed slower decline in relative growth rate (RGR) than shrubs, equivalent to a steeper G by mass (M) scaling exponent in trees (0.77-0.98). The K and Q by M scaling exponents were common across all species (0.80, 0.82), suggesting that the steeper G scaling in trees reflects a size-dependent increase in their growth-based WUE. The common K and Q by M exponents were statistically consistent with the 0.75 of ideal scaling theory. A model based upon xylem anatomy and branching architecture consistently predicted the observed K by M scaling exponents but only when deviations from ideal symmetric branching were incorporated. © 2014 John Wiley & Sons Ltd.

  16. Still a host of hosts for Wolbachia: analysis of recent data suggests that 40% of terrestrial arthropod species are infected.

    Directory of Open Access Journals (Sweden)

    Roman Zug

    Full Text Available Wolbachia are intracellular bacteria that manipulate the reproduction of their arthropod hosts in remarkable ways. They are predominantly transmitted vertically from mother to offspring but also occasionally horizontally between species. In doing so, they infect a huge range of arthropod species worldwide. Recently, a statistical analysis estimated the infection frequency of Wolbachia among arthropod hosts to be 66%. At the same time, the authors of this analysis highlighted some weaknesses of the underlying data and concluded that in order to improve the estimate, a larger number of individuals per species should be assayed and species be chosen more randomly. Here we apply the statistical approach to a more appropriate data set from a recent survey that tested both a broad range of species and a sufficient number of individuals per species. Indeed, we find a substantially different infection frequency: We now estimate the proportion of Wolbachia-infected species to be around 40% which is lower than the previous estimate but still points to a surprisingly high number of arthropods harboring the bacteria. Notwithstanding this difference, we confirm the previous result that, within a given species, typically most or only a few individuals are infected. Moreover, we extend our analysis to include several reproductive parasites other than Wolbachia that were also screened for in the aforementioned empirical survey. For these symbionts we find a large variation in estimated infection frequencies and corroborate the finding that Wolbachia are the most abundant endosymbionts among arthropod species.

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

    Science.gov (United States)

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

    2012-01-01

    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. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Characteristics of green-blue fluorescence generated from the adaxial sides of leaves of tree species.

    Science.gov (United States)

    Nakayama, Masayoshi; Iwashina, Tsukasa

    2017-03-01

    We discovered that some tree species have leaves whose adaxial sides show bright green-blue fluorescence upon exposure to ultraviolet irradiation. In total, 141 native Japanese species belonging to 47 families were analyzed, and the brightness of the leaf fluorescence, represented by the L* values (Lab color space) of the pictures, was evaluated. The species possessing the brightest fluorescent leaves, with L* > 50, were Camellia japonica, Camellia sasanqua, and Cleyera japonica of Theaceae, Osmanthus heterophyllus and Ligustrum japonicum of Oleaceae, Aucuba japonica of Garryaceae, and Trochodendron aralioides of Trochodendraceae. These species are propagated by pollination or seed dispersion by birds, except T. aralioides. The fluorescence was specifically observed in the cuticle tissues of the epidermal cells, indicating that the fluorescence is a signal to other organisms that can perceive the fluorescence under natural light. Species possessing the bright leaves represented 5% of the total species tested, while species possessing dark leaves, with L* ≤ 40, represented 88.6%. We deduce that the fluorescence enables the organisms to easily distinguish the minority species possessing bright leaves from the surrounding plants, which were mostly trees species with dark leaves. The structure of A. japonica var. borealis, in which dark leaves only surround its fruits while the rest of the tree is covered by bright leaves, may be useful to signal the presence of fruits to the organisms. We hypothesize that the fluorescence contributes to the propagation of the tree species by helping birds to distinguish these particular trees and/or locate the fruits.

  19. Summer droughts limit tree growth across 10 temperate species on a productive forest site

    NARCIS (Netherlands)

    Weemstra, M.; Eilmann, B.; Sass-Klaassen, U.; Sterck, F.J.

    2013-01-01

    Studies on climate impacts on tree annual growth are mainly restricted to marginal sites. To date, the climate effects on annual growth of trees in favorable environments remain therefore unclear despite the importance of these sites in terms of forest productivity. Because species respond

  20. An empirical, hierarchical typology of tree species assemblages for assessing forest dynamics under global change scenarios

    Science.gov (United States)

    Jennifer K. Costanza; John W. Coulston; David N. Wear

    2017-01-01

    The composition of tree species occurring in a forest is important and can be affected by global change drivers such as climate change. To inform assessment and projection of global change impacts at broad extents, we used hierarchical cluster analysis and over 120,000 recent forest inventory plots to empirically define forest tree assemblages across the U.S., and...

  1. Long-Term Effects of Exotic Tree Species ( Tectona grandis Linn. F ...

    African Journals Online (AJOL)

    In an effort to combat the declining forestry resources through the establishment of exotic tree species like Tectona grandis, this have lead to processes associated with soils underneath these trees that have not been properly elucidated, particularly the distributions of extractable micronutrients. Results from the study ...

  2. Earthworm abundance and species composition in abandoned tropical croplands: comparisons of tree plantations and secondary forests.

    Science.gov (United States)

    G. Gonzalez; X. Zou; S. Borges

    1996-01-01

    We compared patterns of earthworms abundance and species composition in tree plantation and secondary forest of Puerto Rico. Tree plantations included pine (Pinus caribea Morelet) and mahogany (Swietenia macrophylla King) established in the 1930's; 1960's; and 1970's; secondary forests were naturally regenerated in areas adjacent to these plantations. We...

  3. Estimating tree crown widths for the primary Acadian species in Maine

    Science.gov (United States)

    Matthew B. Russell; Aaron R. Weiskittel

    2012-01-01

    In this analysis, data for seven conifer and eight hardwood species were gathered from across the state of Maine for estimating tree crown widths. Maximum and largest crown width equations were developed using tree diameter at breast height as the primary predicting variable. Quantile regression techniques were used to estimate the maximum crown width and a constrained...

  4. Counteracting selective regimes and host preference evolution in ecotypes of two species of walking-sticks.

    Science.gov (United States)

    Sandoval, C P; Nosil, P

    2005-11-01

    The evolution of ecological specialization has been a central topic in ecology because specialized adaptations to divergent environments can result in reproductive isolation and facilitate speciation. However, the order in which different aspects of habitat adaptation and habitat preference evolve is unclear. Timema walking-stick insects feed and mate on the host plants on which they rest. Previous studies of T. cristinae ecotypes have documented divergent, host-specific selection from visual predators and the evolution of divergent host and mate preferences between populations using different host-plant species (Ceanothus or Adenostoma). Here we present new data that show that T. podura, a nonsister species of T. cristinae, has also formed ecotypes on these host genera and that in both species these ecotypes exhibit adaptive divergence in color-pattern and host preference. Color-pattern morphs exhibit survival trade-offs on different hosts due to differential predation. In contrast, fecundity trade-offs on different hosts do not occur in either species. Thus, host preference in both species has evolved before divergent physiological adaptation but in concert with morphological adaptations. Our results shed light onto which traits are involved in the initial stages of ecological specialization and ecologically based reproductive isolation.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Dar A. Roberts

    2012-06-01

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

  7. An index of forest management intensity based on assessment of harvested tree volume, tree species composition and dead wood origin

    Directory of Open Access Journals (Sweden)

    Tiemo Kahl

    2014-04-01

    Full Text Available Forest management intensity often affects biodiversity, ecosystem processes and ecosystem services. To assess the influence of past management intensity on current ecosystem properties, management intensity must be quantified in a meaningful and reproducible approach. Here we developed the simple yet effective Forest Management Intensity index (ForMI, which is based only on inventory data of the living stand, stumps and dead wood. The ForMI is the sum of three components taking into account: 1. the proportion of harvested tree volume (Iharv, 2. the proportion of tree species that are not part of the natural forest community (Inonat and 3. the proportion of dead wood showing signs of saw cuts (Idwcut. Each component ranges between 0 (no sign of management and 1 (intensive management. Our analysis suggests that the ForMI can be used to assess management intensity in Central European forests for the last 30 to 40 years, depending on decay rates of stumps and dead wood. Our approach was tested using data of 148 forest plots of 1 ha in size in Germany. We found a significant distinction between plots that were previously described as managed and unmanaged as well as between plots comprising trees species of the natural forest community and those with additional, introduced coniferous tree species. We conclude that the index is applicable to a wide range of forest management types, but should not be misinterpreted as an index for old-growth structure.

  8. Fitness consequences of pheromone production and host selection strategies in a tree-killing bark beetle (Coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Pureswaran, Deepa S; Sullivan, Brian T; Ayres, Matthew P

    2006-07-01

    Timing of arrival at a resource often determines an individual's reproductive success. Tree-killing bark beetles can reproduce in healthy trees by attacking in adequate numbers to overcome host defences that could otherwise be lethal. This process is mediated by aggregation and antiaggregation pheromones. Beetles that arrive early in such a "mass attack" must contend with undiminished tree defences, and produce enough pheromones to attract more beetles, but have a head start on gallery construction and egg-laying. Beetles that arrive late may be impeded by competition and diminishing availability of phloem, but should experience fewer costs associated with pheromone production and battling tree defences. We investigated relationships between timing of arrival, body size, pheromone production and fitness in the southern pine beetle, Dendroctonus frontalis. In field experiments, we captured beetles that arrived early (pioneers) and late on slash pine trees, Pinus elliottii, and measured pheromone amounts in their hindguts. We marked gallery entrances of beetles as they landed on a tree and measured their reproductive success after the attack terminated. We found no difference in body size or pheromone amounts between early and late arrivers. Most beetles arrived at the middle of the attack sequence, and excavated longer galleries per day than early arrivers. The number of offspring produced per day by beetles that established galleries midway through mass attack was higher than those that arrived early or very late in the sequence. Our results suggest that beetles do not exhibit adaptive phenotypic plasticity in pre-landing pheromone production, depending on the extent of previous colonisation of a host. Rather, it appears that stabilising selection favours beetles that attack in the middle of the sequence, and contributes to attack synchrony. Synchronous attack on trees is essential before population booms characteristic of tree-killing bark beetles can occur in

  9. Leaf development and photosynthetic properties of three tropical tree species with delayed greening

    NARCIS (Netherlands)

    Cai, Z.Q.; Slot, M.; Fan, Z.X.

    2005-01-01

    Leaf developmental patterns were characterized for three tropical tree species with delayed greening. Changes in the pigment contents, photosynthetic capacity, stomata development, photosystem 2 efficiency, rate of energy dissipation, and the activity of partial protective enzymes were followed in

  10. Promotion of adventitious root formation of difficult-to-root hardwood tree species

    Science.gov (United States)

    Paula M. Pijut; Keith E. Woeste; Charles H. Michler

    2011-01-01

    North American hardwood tree species, such as alder (Alnus spp.), ash (Fraxinus spp.), basswood (Tilia spp.), beech (Fagus spp.), birch (Betula spp.), black cherry (Prunus seratina), black walnut (Juglans nigra), black willow (...

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

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2016-01-01

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

  12. Shifts in relative stocking of common tree species in Kentucky from 1975 to 2004

    Science.gov (United States)

    Christopher M. Oswalt; Jeffrey A. Stringer; Jeffery A. Turner

    2008-01-01

    Changes in species-specific relative stocking indicate the extent to which a species is either increasing or decreasing in a particular system. Changes in relative stocking values of common tree species in Kentucky from 1988 to 2004 were compared to values calculated for 1975 to 1988. Mean annual increase in relative stocking between 1988 and 2004 was greatest for...

  13. Ambrosia Beetle (Coleoptera: Scolytidae) species, flight, and attack on living eastern cottonwood trees

    Science.gov (United States)

    David R. Coyle; Derek C. Booth; M. S. Wallace

    2005-01-01

    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...

  14. Dinucleotide Composition in Animal RNA Viruses Is Shaped More by Virus Family than by Host Species.

    Science.gov (United States)

    Di Giallonardo, Francesca; Schlub, Timothy E; Shi, Mang; Holmes, Edward C

    2017-04-15

    Viruses use the cellular machinery of their hosts for replication. It has therefore been proposed that the nucleotide and dinucleotide compositions of viruses should match those of their host species. If this is upheld, it may then be possible to use dinucleotide composition to predict the true host species of viruses sampled in metagenomic surveys. However, it is also clear that different taxonomic groups of viruses tend to have distinctive patterns of dinucleotide composition that may be independent of host species. To determine the relative strength of the effect of host versus virus family in shaping dinucleotide composition, we performed a comparative analysis of 20 RNA virus families from 15 host groupings, spanning two animal phyla and more than 900 virus species. In particular, we determined the odds ratios for the 16 possible dinucleotides and performed a discriminant analysis to evaluate the capability of virus dinucleotide composition to predict the correct virus family or host taxon from which it was isolated. Notably, while 81% of the data analyzed here were predicted to the correct virus family, only 62% of these data were predicted to their correct subphylum/class host and a mere 32% to their correct mammalian order. Similarly, dinucleotide composition has a weak predictive power for different hosts within individual virus families. We therefore conclude that dinucleotide composition is generally uniform within a virus family but less well reflects that of its host species. This has obvious implications for attempts to accurately predict host species from virus genome sequences alone. IMPORTANCE Determining the processes that shape virus genomes is central to understanding virus evolution and emergence. One question of particular importance is why nucleotide and dinucleotide frequencies differ so markedly between viruses. In particular, it is currently unclear whether host species or virus family has the biggest impact on dinucleotide frequencies and

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

    Science.gov (United States)

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

    2015-10-01

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

  16. Mountain landscapes offer few opportunities for high-elevation tree species migration

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Climate change is anticipated to alter plant species distributions. Regional context, notably the spatial complexity of climatic gradients, may influence species migration potential. While high-elevation species may benefit from steep climate gradients in mountain regions, their persistence may be threatened by limited suitable habitat as land area decreases with elevation. To untangle these apparently contradictory predictions for mountainous regions, we evaluated the climatic suitability of four coniferous forest tree species of the western United States based on species distribution modeling (SDM) and examined changes in climatically suitable areas under predicted climate change. We used forest structural information relating to tree species dominance, productivity, and demography from an extensive forest inventory system to assess the strength of inferences made with a SDM approach. We found that tree species dominance, productivity, and recruitment were highest where climatic suitability (i.e., probability of species occurrence under certain climate conditions) was high, supporting the use of predicted climatic suitability in examining species risk to climate change. By predicting changes in climatic suitability over the next century, we found that climatic suitability will likely decline, both in areas currently occupied by each tree species and in nearby unoccupied areas to which species might migrate in the future. These trends were most dramatic for high elevation species. Climatic changes predicted over the next century will dramatically reduce climatically suitable areas for high-elevation tree species while a lower elevation species, Pinus ponderosa, will be well positioned to shift upslope across the region. Reductions in suitable area for high-elevation species imply that even unlimited migration would be insufficient to offset predicted habitat loss, underscoring the vulnerability of these high-elevation species to climatic changes.

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

    Directory of Open Access Journals (Sweden)

    Humberto Esquivel-Mimenza

    2013-08-01

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

  18. The use of hyperspectral data for tree species discrimination: Combining binary classifiers

    CSIR Research Space (South Africa)

    Dastile, X

    2010-11-01

    Full Text Available of Hyperspectral data for tree species discrimination: Combining binary classifiers by Xolani Dastile supervised by Professor G. Jager Doctor P. Debba 2RU SASA 2010 1. Outline ? Hyperspectral Remote sensing ? Data description ? Classification... Sensor material Active Sensor Passive Sensor Incident radiation Reflected radiation Incident radiation Reflected radiation r i R R 4RU SASA 2010 3. Data description ? Aim: Assess tree species diversity in Kruger National Park ? Study...

  19. Predicting climate change extirpation risk for central and southern Appalachian forest tree species

    Science.gov (United States)

    Kevin M. Potter; William W. Hargrove; Frank H. Koch

    2010-01-01

    Climate change will likely pose a severe threat to the viability of certain forest tree species, which will be forced either to adapt to new conditions or to shift to more favorable environments if they are to survive. Several forest tree species of the central and southern Appalachians may be at particular risk, since they occur in limited high-elevation ranges and/or...

  20. Do temperate tree species diversity and identity influence soil microbial community function and composition?

    Science.gov (United States)

    Khlifa, Rim; Paquette, Alain; Messier, Christian; Reich, Peter B; Munson, Alison D

    2017-10-01

    Studies of biodiversity-ecosystem function in treed ecosystems have generally focused on aboveground functions. This study investigates intertrophic links between tree diversity and soil microbial community function and composition. We examined how microbial communities in surface mineral soil responded to experimental gradients of tree species richness (SR), functional diversity (FD), community-weighted mean trait value (CWM), and tree identity. The site was a 4-year-old common garden experiment near Montreal, Canada, consisting of deciduous and evergreen tree species mixtures. Microbial community composition, community-level physiological profiles, and respiration were evaluated using phospholipid fatty acid (PLFA) analysis and the MicroResp™ system, respectively. The relationship between tree species richness and glucose-induced respiration (GIR), basal respiration (BR), metabolic quotient (qCO 2) followed a positive but saturating shape. Microbial communities associated with species mixtures were more active (basal respiration [BR]), with higher biomass (glucose-induced respiration [GIR]), and used a greater number of carbon sources than monocultures. Communities associated with deciduous tree species used a greater number of carbon sources than those associated with evergreen species, suggesting a greater soil carbon storage capacity. There were no differences in microbial composition (PLFA) between monocultures and SR mixtures. The FD and the CWM of several functional traits affected both BR and GIR. In general, the CWM of traits had stronger effects than did FD, suggesting that certain traits of dominant species have more effect on ecosystem processes than does FD. Both the functions of GIR and BR were positively related to aboveground tree community productivity. Both tree diversity (SR) and identity (species and functional identity-leaf habit) affected soil microbial community respiration, biomass, and composition. For the first time, we identified

  1. Evolution of the M gene of the influenza A virus in different host species: large-scale sequence analysis

    Directory of Open Access Journals (Sweden)

    Kamigaki Taro

    2009-05-01

    Full Text Available Abstract Background Influenza A virus infects not only humans, but also other species including avian and swine. If a novel influenza A subtype acquires the ability to spread between humans efficiently, it could cause the next pandemic. Therefore it is necessary to understand the evolutionary processes of influenza A viruses in various hosts in order to gain better knowledge about the emergence of pandemic virus. The virus has segmented RNA genome and 7th segment, M gene, encodes 2 proteins. M1 is a matrix protein and M2 is a membrane protein. The M gene may be involved in determining host tropism. Besides, novel vaccines targeting M1 or M2 protein to confer cross subtype protection have been under development. We conducted the present study to investigate the evolution of the M gene by analyzing its sequence in different species. Results Phylogenetic tree revealed host-specific lineages and evolution rates were different among species. Selective pressure on M2 was stronger than that on M1. Selective pressure on M1 for human influenza was stronger than that for avian influenza, as well as M2. Site-by-site analyses identified one site (amino acid position 219 in M1 as positively selected in human. Positions 115 and 121 in M1, at which consensus amino acids were different between human and avian, were under negative selection in both hosts. As to M2, 10 sites were under positive selection in human. Seven sites locate in extracellular domain. That might be due to host's immune pressure. One site (position 27 positively selected in transmembrane domain is known to be associated with drug resistance. And, two sites (positions 57 and 89 locate in cytoplasmic domain. The sites are involved in several functions. Conclusion The M gene of influenza A virus has evolved independently, under different selective pressure on M1 and M2 among different hosts. We found potentially important sites that may be related to host tropism and immune responses. These

  2. Evolution of the M gene of the influenza A virus in different host species: large-scale sequence analysis.

    Science.gov (United States)

    Furuse, Yuki; Suzuki, Akira; Kamigaki, Taro; Oshitani, Hitoshi

    2009-05-29

    Influenza A virus infects not only humans, but also other species including avian and swine. If a novel influenza A subtype acquires the ability to spread between humans efficiently, it could cause the next pandemic. Therefore it is necessary to understand the evolutionary processes of influenza A viruses in various hosts in order to gain better knowledge about the emergence of pandemic virus. The virus has segmented RNA genome and 7th segment, M gene, encodes 2 proteins. M1 is a matrix protein and M2 is a membrane protein. The M gene may be involved in determining host tropism. Besides, novel vaccines targeting M1 or M2 protein to confer cross subtype protection have been under development. We conducted the present study to investigate the evolution of the M gene by analyzing its sequence in different species. Phylogenetic tree revealed host-specific lineages and evolution rates were different among species. Selective pressure on M2 was stronger than that on M1. Selective pressure on M1 for human influenza was stronger than that for avian influenza, as well as M2. Site-by-site analyses identified one site (amino acid position 219) in M1 as positively selected in human. Positions 115 and 121 in M1, at which consensus amino acids were different between human and avian, were under negative selection in both hosts. As to M2, 10 sites were under positive selection in human. Seven sites locate in extracellular domain. That might be due to host's immune pressure. One site (position 27) positively selected in transmembrane domain is known to be associated with drug resistance. And, two sites (positions 57 and 89) locate in cytoplasmic domain. The sites are involved in several functions. The M gene of influenza A virus has evolved independently, under different selective pressure on M1 and M2 among different hosts. We found potentially important sites that may be related to host tropism and immune responses. These sites may be important for evolutional process in different

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

    Directory of Open Access Journals (Sweden)

    Ilze Jankovska

    2015-12-01

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

  4. Demography of exploited tree species in the Bolivian Amazon

    NARCIS (Netherlands)

    Zuidema, P.A.

    2000-01-01

    Tropical forests are threatened world-wide. Therefore, there is a search for ways to use the forests in a sustainable way, as this could assist in the conservation of these special ecosystems. Non-timber products collected from trees in tropical forests are often mentioned as examples of

  5. The Germination of Several Tree Species in Plastic Greenhouses

    Science.gov (United States)

    Howard M. Phipps

    1969-01-01

    The technique of growing tree seedlings in plastic greenhouses is being evaluated for red pine, jack pine, white spruce, and yellow birch at the Chittenden Nursery in northern Lower Michigan. Both a long growing season and a normal-length growing season in plastic greenhouses were compared with standard outdoor nursery beds (control). First-year results showed that...

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

    African Journals Online (AJOL)

    Trees, which are important for the sustenance of life and the health of our planet, are disappearing at an alarming rate. Consequently, the need for actions to develop effective strategies to conserve them is receiving considerable attention worldwide. Forest genetic resources are fast becoming depleted in most natural ...

  7. Evaluation of land suitability for selected tree species in the ...

    African Journals Online (AJOL)

    This paper aimed at evaluating the potential of the different soil attributes for plantation of selected forest trees (Faidherbia albida, Eucalyptus camaldulensis and Balanitus aegiptica) dominantly grown in the northern highlands of Ethiopia. The study was conducted at Korir watershed, northern Ethiopia. The method used to ...

  8. Modelling dimensional growth of three street tree species in the ...

    African Journals Online (AJOL)

    The results could also be used in the process of modelling energy use reduction, air pollution uptake, rainfall interception, carbon sequestration and microclimate modification of urban forests such as those found in the City of Tshwane. Keywords: allometry; regression; size relationships; tree growth; urban forests. Southern ...

  9. Evaluation of seven drought tolerant tree species for central California

    Science.gov (United States)

    E.G. McPherson; S. Albers

    2014-01-01

    Climate change poses challenges for the Southwest, where an already parched region is expected to get hotter and, in its southern half, significantly drier (Garfin et al. 2013). Increased heat and sustained drought will stress water sources and redefine urban landscapes. As landscapes gradually evolve from lush to xeric, tolerance of trees to water-related stress...

  10. Chromosome numbers of some indigenous tree species of Ethiopia ...

    African Journals Online (AJOL)

    Chromosome data are essential information for any organism and many chromosome investigations have been performed, providing important characters for plant systematic and evolutionary analysis as well as for germplasm improvement. Trees are important to the wellbeing of people in every country, as they have ...

  11. Extending the dormant bud cryopreservation method to new tree species

    Science.gov (United States)

    In cryopreservation of germplasm, using dormant winter buds (DB) as source plant material is economically favorable over tissue culture options. Although the DB cryopreservation method has been known for many years, the approach is feasible only for cryopreserving a select number of temperate tree s...

  12. Tree species diversity under pastoral and farming systems in Kilosa ...

    African Journals Online (AJOL)

    Household survey solicited information on perceptions of local communities on drivers that influenced tree stocking and diversity of their forests. A forest inventory was ... Average stocking for the forest under pastoral system was 235 stem ha-1, whereas that of farming system was 209 stem ha-1. Basal areas of 13m2ha-1 ...

  13. Seasonal changes in infection with trematode species utilizing jellyfish as hosts: evidence of transmission to definitive host fish via medusivory.

    Science.gov (United States)

    Kondo, Yusuke; Ohtsuka, Susumu; Hirabayashi, Takeshi; Okada, Shoma; Ogawa, Nanako O; Ohkouchi, Naohiko; Shimazu, Takeshi; Nishikawa, Jun

    2016-01-01

    In the Seto Inland Sea of western Japan, metacercariae of three species of trematodes, Lepotrema clavatum Ozaki, 1932, Cephalolepidapedon saba Yamaguti, 1970, and Opechona olssoni (Yamaguti, 1934), were found in the mesoglea of the jellyfish Aurelia aurita s.l., Chrysaora pacifica, and Cyanea nozakii. Moreover, these jellyfish frequently harbored juveniles of the fish species Psenopsis anomala, Thamnaconus modestus, and Trachurus japonicus. The former two fish species are well-known medusivores. We investigated seasonal changes in the prevalence and intensity of these metacercariae in their host jellyfish from March 2010 to September 2012 and presumed that infection by the trematodes of the definitive host fish occurs through these associations. The mean intensity of metacercariae in A. aurita s.l. clearly showed seasonality, being consistently high in June of each year. The intensity of metacercariae in C. nozakii was highest among all jellyfish hosts and appeared to be enhanced by medusivory of this second intermediate, and/or paratenic host. Trophic interactions between jellyfish and associated fish were verified using both gut content and stable isotope analyses. The detection of trematodes and nematocysts in the guts of P. anomala and T. modestus juveniles, in addition to stable isotope analysis, suggests that transmission of the parasites occurs via prey-predator relationships. In addition, the stable isotope analysis also suggested that P. anomala is more nutritionally dependent on jellyfish than Th. modestus and Tr. japonicus. © Y. Kondo et al., published by EDP Sciences, 2016.

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

    Directory of Open Access Journals (Sweden)

    Nadja Rüger

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

  15. Cross-Species Virus-Host Protein-Protein Interactions Inhibiting Innate Immunity

    Science.gov (United States)

    2016-07-01

    virus families with know or suspected histories of changes in host-species tropism from animal to humans. In the Paramyxoviridae family, Hendra ...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-16-79 Cross-species virus -host...Cross-species virus -host protein-protein interactions inhibiting innate immunity What are the major goals of the project? List the major goals of

  16. Global to local genetic diversity indicators of evolutionary potential in tree species within and outside forests

    DEFF Research Database (Denmark)

    Graudal, Lars; Aravanopoulos, Filippos; Bennadji, Zohra

    2014-01-01

    , trends and potentials of the world's tree genetic resources to support sustainable growth. The state of the genetic diversity will be based on trends in population distributions and diversity patterns for selected species. The productivity of the genetic resource of trees in current use will reflect...... distributions (patterns of genetic variation of key adaptive traits in the ecological space) of selected species is a realistic way of assessing the trend of intra-specific variation, and thus provides a state indicator of tree genetic diversity also able to reflect possible pressures threatening genetic...

  17. Considering extinction of dependent species during translocation, ex situ conservation, and assisted migration of threatened hosts.

    Science.gov (United States)

    Moir, Melinda L; Vesk, Peter A; Brennan, Karl E C; Poulin, Robert; Hughes, Lesley; Keith, David A; McCarthy, Michael A; Coates, David J

    2012-04-01

    Translocation, introduction, reintroduction, and assisted migrations are species conservation strategies that are attracting increasing attention, especially in the face of climate change. However, preventing the extinction of the suite of dependent species whose host species are threatened is seldom considered, and the effects on dependent species of moving threatened hosts are unclear. There is no published guidance on how to decide whether to move species, given this uncertainty. We examined the dependent-host system of 4 disparate taxonomic groups: insects on the feather-leaf banksia (Banksia brownii), montane banksia (B. montana), and Stirling Range beard heath (Leucopogon gnaphalioides); parasites of wild cats; mites and ticks on Duvaucel's gecko (Hoplodactylus duvaucelii) and tuatara (Sphenodon punctatus); and internal coccidian parasites of Cirl Bunting (Emberiza cirlus) and Hihi (Notiomystis cincta). We used these case studies to demonstrate a simple process for use in species- and community-level assessments of efforts to conserve dependents with their hosts. The insects dependent on Stirling Range beard heath and parasites on tigers (Panthera tigris) appeared to represent assemblages that would not be conserved by ex situ host conservation. In contrast, for the cases of dependent species we examined involving a single dependent species (internal parasites of birds and the mite Geckobia naultina on Duvaucel's gecko), ex situ conservation of the host species would also conserve the dependent species. However, moving dependent species with their hosts may be insufficient to maintain viable populations of the dependent species, and additional conservation strategies such as supplementing populations may be needed. ©2012 Society for Conservation Biology.

  18. Host-related genetic differentiation in the anther smut fungus Microbotryum violaceum in sympatric, parapatric and allopatric populations of two host species Silene latifolia and S-dioica

    NARCIS (Netherlands)

    Van Putten, WF; Biere, A; Van Damme, JMM

    We investigated genetic diversity in West European populations of the fungal pathogen Microbotryum violaceum in sympatric, parapatric and allopatric populations of the host species Silene latifolia and S. dioica, using four polymorphic microsatellite loci. In allopatric host populations, the fungus

  19. Host-related genetic differentiation in the anther smut fungus Microbotryum violaceum in sympatric, parapatric and allopatric populations of two host species Silene latifolia and S. dioica

    NARCIS (Netherlands)

    Van Putten, W.F.; Biere, A.; Van Damme, J.M.M.

    2005-01-01

    We investigated genetic diversity in West European populations of the fungal pathogen Microbotryum violaceum in sympatric, parapatric and allopatric populations of the host species Silene latifolia and S. dioica, using four polymorphic microsatellite loci. In allopatric host populations, the fungus

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

    Directory of Open Access Journals (Sweden)

    Edward Ayres

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

  1. CONDITIONS FOR COEXISTENCE OF FRESHWATER MUSSEL SPECIES VIA PARTITIONING OF FISH HOST RESOURCES

    Science.gov (United States)

    Riverine freshwater mussel species can be found in highly diverse communities where many similar species coexist. Mussel species potentially compete for food and space as adults, and for fish host resources during the larval (glochidial) stage. Resource partitioning at the larv...

  2. Soil respiration and rates of soil carbon turnover differ among six common European tree species

    DEFF Research Database (Denmark)

    Vesterdal, Lars; Elberling, Bo; Christiansen, Jesper Riis

    2012-01-01

    The knowledge of tree species effects on soil organic carbon (C) turnover based on rigorous experimental designs is limited for common European deciduous tree species. We assessed soil respiration, and rates of C turnover in six tree species in a more than 30-year-old common garden experiment...... of C turnover were estimated by (i) the ratio of estimated soil heterotrophic respiration (R h) to C stock in forest floor and top mineral soil, (ii) the ratio of litterfall C to forest floor C, (iii) foliar mass loss in litterbags, and (iv) mineral soil C turnover assessed by laboratory incubation....... Soil respiration differed significantly among several species and increased in the order beechSoil respiration was temperature limited with no significant species difference in Q10. Norway spruce soils were significantly driest, and soil respiration was also limited by soil...

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

    Science.gov (United States)

    Woodward, Andrea

    1998-01-01

    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.

  4. Surface Water Storage Capacity of Twenty Tree Species in Davis, California.

    Science.gov (United States)

    Xiao, Qingfu; McPherson, E Gregory

    2016-01-01

    Urban forestry is an important green infrastructure strategy because healthy trees can intercept rainfall, reducing stormwater runoff and pollutant loading. Surface saturation storage capacity, defined as the thin film of water that must wet tree surfaces before flow begins, is the most important variable influencing rainfall interception processes. Surface storage capacity is known to vary widely among tree species, but it is little studied. This research measured surface storage capacities of 20 urban tree species in a rainfall simulator. The measurement system included a rainfall simulator, digital balance, digital camera, and computer. Eight samples were randomly collected from each tree species. Twelve rainfall intensities (3.5-139.5 mm h) were simulated. Leaf-on and leaf-off simulations were conducted for deciduous species. Stem and foliar surface areas were estimated using an image analysis method. Results indicated that surface storage capacities varied threefold among tree species, 0.59 mm for crape myrtle ( L.) and 1.81 mm for blue spruce ( Engelm.). The mean value across all species was 0.86 mm (0.11 mm SD). To illustrate application of the storage values, interception was simulated and compared across species for a 40-yr period with different rainfall intensities and durations. By quantifying the potential for different tree species to intercept rainfall under a variety of meteorological conditions, this study provides new knowledge that is fundamental to validating the cost-effectiveness of urban forestry as a green infrastructure strategy and designing functional plantings. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  5. Iodine uptake and distribution in horticultural and fruit tree species

    OpenAIRE

    Alessandra Caffagni; Nicola Pecchioni; Pierluigi Meriggi; Valerio Bucci; Emidio Sabatini; Nazareno Acciarri; Tommaso Ciriaci; Laura Pulcini; Nazzareno Felicioni; Massimiliano Beretta; Justyna Milc

    2012-01-01

    Iodine is an essential microelement for humans and iodine deficiency disorder (IDD) is one of the most widespread nutrient-deficiency diseases in the world. Iodine biofortification of plants provides an attractive opportunity to increase iodine intake in humans and to prevent and control IDD. This study was conducted to investigate the iodine uptake and accumulation in edible portion of two fruit trees: plum and nectarine, and two horticultural crops: tomato and potato. Two type of iodine tre...

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

    African Journals Online (AJOL)

    However, at 30-45 cm depth, Ca, Mg, K and N concentrations were higher in AS than in DS. The nutrient element concentrations were high at 0-15 cm than further down the soil depths for the two forests. The land quality indexes of the principal nutrients N, P, K, Ca and Mg were higher in AS than in DS. Thus, eight tree ...

  7. Tree-Species Classification in Subtropical Forests Using Airborne Hyperspectral and LiDAR Data

    Directory of Open Access Journals (Sweden)

    Xin Shen

    2017-11-01

    Full Text Available Accurate classification of tree-species is essential for sustainably managing forest resources and effectively monitoring species diversity. In this study, we used simultaneously acquired hyperspectral and LiDAR data from LiCHy (Hyperspectral, LiDAR and CCD airborne system to classify tree-species in subtropical forests of southeast China. First, each individual tree crown was extracted using the LiDAR data by a point cloud segmentation algorithm (PCS and the sunlit portion of each crown was selected using the hyperspectral data. Second, different suites of hyperspectral and LiDAR metrics were extracted and selected by the indices of Principal Component Analysis (PCA and the mean decrease in Gini index (MDG from Random Forest (RF. Finally, both hyperspectral metrics (based on whole crown and sunlit crown and LiDAR metrics were assessed and used as inputs to Random Forest classifier to discriminate five tree-species at two levels of classification. The results showed that the tree delineation approach (point cloud segmentation algorithm was suitable for detecting individual tree in this study (overall accuracy = 82.9%. The classification approach provided a relatively high accuracy (overall accuracy > 85.4% for classifying five tree-species in the study site. The classification using both hyperspectral and LiDAR metrics resulted in higher accuracies than only hyperspectral metrics (the improvement of overall accuracies = 0.4–5.6%. In addition, compared with the classification using whole crown metrics (overall accuracies = 85.4–89.3%, using sunlit crown metrics (overall accuracies = 87.1–91.5% improved the overall accuracies of 2.3%. The results also suggested that fewer of the most important metrics can be used to classify tree-species effectively (overall accuracies = 85.8–91.0%.

  8. Transcriptomes of arbuscular mycorrhizal fungi and litchi host interaction after tree girdling

    Directory of Open Access Journals (Sweden)

    Bo eShu

    2016-03-01

    Full Text Available Trunk girdling can increase carbohydrate content above the girdling site and is an important strategy for inhibiting new shoot growth to promote flowering in cultivated litchi (Litchi chinenis Sonn.. However, girdling inhibits carbohydrate transport to the root in nearly all of the fruit development periods and consequently decreases root absorption. The mechanism through which carbohydrates regulate root development in arbuscular mycorrhiza (AM remains largely unknown. Carbohydrate content, AM colonization, and transcriptome in the roots were analyzed to elucidate the interaction between host litchi and AM fungi when carbohydrate content decreases. Girdling decreased glucose, fructose, sucrose, quebrachitol and starch contents in the litchi mycorrhizal roots, thereby reducing AM colonization. RNA-seq achieved approximately 60 million reads of each sample, with an average length of reads reaching 100 bp. Assembly of all the reads of the 30 samples produced 671,316 transcripts and 381,429 unigenes, with average lengths of 780 and 643 bp, respectively. Litchi (54,100 unigenes and AM fungi unigenes (33,120 unigenes were achieved through sequence annotation during decreased carbohydrate content. Analysis of differentially expressed genes (DEG showed that flavonoids, alpha-linolenic acid, and linoleic acid are the main factors that regulate AM colonization in litchi. However, flavonoids may play a role in detecting the stage at which carbohydrate content decreases; alpha-linolenic acid or linoleic acid may affect AM formation under the adaptation process. Litchi trees stimulated the expression of defense-related genes and downregulated symbiosis signal-transduction genes to inhibit new AM colonization. Moreover, transcription factors of the AP2, ERF, Myb, WRKY, bHLH families, and lectin genes altered maintenance of litchi mycorrhizal roots in the post-symbiotic stage for carbohydrate starvation. Similar to those of the litchi host, the E3 ubiquitin

  9. Transcriptomes of Arbuscular Mycorrhizal Fungi and Litchi Host Interaction after Tree Girdling.

    Science.gov (United States)

    Shu, Bo; Li, Weicai; Liu, Liqin; Wei, Yongzan; Shi, Shengyou

    2016-01-01

    Trunk girdling can increase carbohydrate content above the girdling site and is an important strategy for inhibiting new shoot growth to promote flowering in cultivated litchi (Litchi chinensis Sonn.). However, girdling inhibits carbohydrate transport to the root in nearly all of the fruit development periods and consequently decreases root absorption. The mechanism through which carbohydrates regulate root development in arbuscular mycorrhiza (AM) remains largely unknown. Carbohydrate content, AM colonization, and transcriptome in the roots were analyzed to elucidate the interaction between host litchi and AM fungi when carbohydrate content decreases. Girdling decreased glucose, fructose, sucrose, quebrachitol, and starch contents in the litchi mycorrhizal roots, thereby reducing AM colonization. RNA-seq achieved approximately 60 million reads of each sample, with an average length of reads reaching 100 bp. Assembly of all the reads of the 30 samples produced 671,316 transcripts and 381,429 unigenes, with average lengths of 780 and 643 bp, respectively. Litchi (54,100 unigenes) and AM fungi unigenes (33,120 unigenes) were achieved through sequence annotation during decreased carbohydrate content. Analysis of differentially expressed genes (DEG) showed that flavonoids, alpha-linolenic acid, and linoleic acid are the main factors that regulate AM colonization in litchi. However, flavonoids may play a role in detecting the stage at which carbohydrate content decreases; alpha-linolenic acid or linoleic acid may affect AM formation under the adaptation process. Litchi trees stimulated the expression of defense-related genes and downregulated symbiosis signal-transduction genes to inhibit new AM colonization. Moreover, transcription factors of the AP2, ERF, Myb, WRKY, bHLH families, and lectin genes altered maintenance of litchi mycorrhizal roots in the post-symbiotic stage for carbohydrate starvation. Similar to those of the litchi host, the E3 ubiquitin ligase complex

  10. KEY TO THE POWDERY MILDEW SPECIES ON THE BASIS OF THE HOST PLANT FAMILIES AND GENERA

    Directory of Open Access Journals (Sweden)

    E. V. Rakhimova

    2015-05-01

    Full Text Available Key on the basis of the host plant taxonomy, symptoms of the infected plants and microscopic features of fungi was composed for identification of powdery mildews of the Kazakhstan. Features, which were used for identification of fungus, were the number of asci in cleistothecium, the number of ascospores in ascus and the type of appendages of cleistothecium. Key was composed for 81 species and 25 variations of Erysiphales fungi, infecting 739 species of host plants, which belong to 305 genera.

  11. Hybridization between two cestode species and its consequences for intermediate host range

    Directory of Open Access Journals (Sweden)

    Henrich Tina

    2013-02-01

    Full Text Available Abstract Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii, both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively. Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  12. Hybridization between two cestode species and its consequences for intermediate host range.

    Science.gov (United States)

    Henrich, Tina; Benesh, Daniel P; Kalbe, Martin

    2013-02-07

    Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F(1) hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii), both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively). We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  13. Tree species diversity and utilities in a contracting lowland hillside rainforest fragment in Central Vietnam

    Directory of Open Access Journals (Sweden)

    Yen Thi Van

    2017-06-01

    Full Text Available Background Within the highly bio-diverse ‘Northern Vietnam Lowland Rain Forests Ecoregion’ only small, and mostly highly modified forestlands persist within vast exotic-species plantations. The aim of this study was to elucidate vegetation patterns of a secondary hillside rainforest remnant (elevation 120–330 m, 76 ha as an outcome of natural processes, and anthropogenic processes linked to changing forest values. Methods In the rainforest remnant tree species and various bio-physical parameters (relating to soils and terrain were surveyed on forty 20 m × 20 m sized plots. The forest's vegetation patterns and tree diversity were analysed using dendrograms, canonical correspondence analysis, and other statistical tools. Results Forest tree species richness was high (172 in the survey, 94 per hectare, including many endemic species (>16%; some recently described. Vegetation patterns and diversity were largely explained by topography, with colline/sub-montane species present mainly along hillside ridges, and lowland/humid-tropical species predominant on lower slopes. Scarcity of high-value timber species reflected past logging, whereas abundance of light-demanding species, and species valued for fruits, provided evidence of human-aided forest restoration and ‘enrichment’ in terms of useful trees. Exhaustion of sought-after forest products, and decreasing appreciation of non-wood products concurred with further encroachment of exotic plantations in between 2010 and 2015. Regeneration of rare tree species was reduced probably due to forest isolation. Conclusions Despite long-term anthropogenic influences, remnant forests in the lowlands of Vietnam can harbor high plant biodiversity, including many endangered species. Various successive future changes (vanishing species, generalist dominance, and associated forest structural-qualitative changes are, however, expected to occur in small forest fragments. Lowland forest biodiversity can only

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

    Science.gov (United States)

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

    2013-03-01

    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

  15. Padus serotina (Rosaceae, a new host plant for some species of parasitic microfungi

    Directory of Open Access Journals (Sweden)

    Nałgorzata Ruszkiewicz-Michalska

    2014-08-01

    Full Text Available Four species of parasitic microfungi were collected recenUy on Padus serotina (Ehrh. Borkh. (Rosaceae in Poland. Three species, Phyllactina guttata (Wallr. ex Fr. Lév. (Erysiphales, Monilia linhartiana Sacc. (Hyphomycetes, and Microsphaeropsis olivacea (Bonord. Höhn. (Coelomycetes, have not been reported before on thc plant, and Padus serotina is a new host for them. Monnilia linhartiana Sacc. is a new species for Poland. The fourth species, Podosphaera tridactyla (Wallr. de Baly var. tridactyla (Erysiphales, is known only from three localities in Europe, and has been collected on the host plant in Poland for the first time.

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

    Directory of Open Access Journals (Sweden)

    Kyle Dexter

    2016-09-01

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

  17. Species Differentiation of Chinese Mollitrichosiphum (Aphididae: Greenideinae) Driven by Geographical Isolation and Host Plant Acquirement

    Science.gov (United States)

    Zhang, Ruiling; Huang, Xiaolei; Jiang, Liyun; Lei, Fumin; Qiao, Gexia

    2012-01-01

    The impact of both the uplift of the Qinghai-Tibetan Plateau (QTP) and the separation of the Taiwan and Hainan Islands on the evolution of the fauna and flora in adjacent regions has been a topic of considerable interest. Mollitrichosiphum is a polyphagous insect group with a wide range of host plants (14 families) and distributions restricted to Southeast Asia. Based on the mitochondrial Cytochrome C Oxidase Subunit I (COI) and Cytochrome b (Cytb) genes, the nuclear elongation factor-1α (EF-1α) gene, and the detailed distribution and host plant data, we investigated the species differentiation modes of the Chinese Mollitrichosiphum species. Phylogenetic analyses supported the monophyly of Mollitrichosiphum. The divergence time of Mollitrichosiphum tenuicorpus (c. 11.0 mya (million years ago)), Mollitrichosiphum nandii and Mollitrichosiphum montanum (c. 10.6 mya) was within the time frame of the uplift of the QTP. Additionally, basal species mainly fed on Fagaceae, while species that fed on multiple plants diverged considerably later. Ancestral state reconstruction suggests that Fagaceae may be the first acquired host, and the acquisition of new hosts and the expansion of host range may have promoted species differentiation within this genus. Overall, it can be concluded that geographical isolation and the expansion of the host plant range may be the main factors driving species differentiation of Mollitrichosiphum. PMID:22949873

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-01

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

  19. Tree-Level Harvest Optimization for Structure-Based Forest Management Based on the Species Mingling Index

    Directory of Open Access Journals (Sweden)

    Pete Bettinger

    2015-04-01

    Full Text Available This novel research investigated the use of a heuristic process to inform tree-level harvest decisions guided by the need to maximize the interspersion of tree species across a forest. In the heuristic process, a species mingling value for each tree was computed using both (1 neighbors that were simply of a different species than the reference tree and (2 neighbors that were uniquely different species from both the reference tree and other neighbors of the reference tree. The tree-level species mingling value was averaged for the stand, which was then subject to a maximization process. Constraints included residual tree density levels and minimum tree volume harvest levels. In two case studies, results suggest that the species mingling index at the stand level can be significantly increased over randomly allocated harvest decisions using the heuristic process described. In the case studies, we illustrate how this type of process can inform management decisions by suggesting the distance between residual trees of similar species given the initial stand structure and the objectives and constraints. The work represents a unique tree-level optimization approach that one day may be of value as new technologies are developed to map the location of individual trees in a timely and efficient manner.

  20. Monogenean parasite species descriptions from Labeo spp. hosts in ...

    African Journals Online (AJOL)

    Specimens of Labeo capensis (n = 13) and Labeo umbratus (n = 26) from the Vaal Dam (South Africa) were collected and examined for gill and skin monogenean parasites. Three new Dactylogyrus and one new Dogielius species are described. Dactylogyrus iwani n.sp. (longer inner root on anchor and predominates on L.

  1. Vertical distribution and species coexistence of tree hole mosquitoes in Louisiana.

    Science.gov (United States)

    Schreiber, E T; Meek, C L; Yates, M M

    1988-03-01

    Vertical distribution and species coexistence of mosquitoes inhabiting a deciduous forest in southern Louisiana were determined using 470 ml black jars for larval collections at ground level and 1, 3, 5, 7 and 9 m on selected trees. Specific preferences for discrete microhabitats by Aedes triseriatus, Ae. hendersoni, Ae. vexans and Ae. albopictus were not evident. Niche overlap indices, however, showed little overlap of these species and seemed to indicate that the mosquitoes partitioned the ovipositional/larval sites. Competition between the most abundant species, Ae. triseriatus and Ae. albopictus, was not apparent. The tree hole mosquito community structure appeared to be mediated by the predator, Toxorhynchites rutilus septentrionalis.

  2. Climate-related genetic variation in a threatened tree species, Pinus albicaulis

    Science.gov (United States)

    Marcus V. Warwell; Ruth G. Shaw

    2017-01-01

    PREMISE OF THE STUDY: With ongoing climate change, understanding of intraspecific adaptive variation is critical for conservation and restoration of plant species. Such information is especially scarce for threatened and endangered tree species, such as Pinus albicaulis Engelm. Therefore, our principal aims were to assess adaptive variation and characterize its...

  3. Assessing tree species assemblages in highly disturbed Puerto Rican karst landscapes using forest inventory data.

    Science.gov (United States)

    Thomas James Brandeis

    2006-01-01

    Tree species assemblages described by landscape-scale forest inventory data both agreed and differed from those described by intensive, site specific studies in Puerto Rico’s highly disturbed northern karst belt. Species assemblages found on hill tops (typified by Tabebuia heterophylla or Bursera simaruba with Coccoloba diversifolia, Licaria parvifolia, and Drypetes...

  4. Factors influencing non-native tree species distribution in urban landscapes

    Science.gov (United States)

    Wayne C. Zipperer

    2010-01-01

    Non-native species are presumed to be pervasive across the urban landscape. Yet, we actually know very little about their actual distribution. For this study, vegetation plot data from Syracuse, NY and Baltimore, MD were used to examine non-native tree species distribution in urban landscapes. Data were collected from remnant and emergent forest patches on upland sites...

  5. Trees of Laos and Vietnam: a field guide to 100 economically or ecologically important species

    NARCIS (Netherlands)

    Sam, Hoang Van; Nanthavong, Khamseng; Keßler, P.J.A.

    2004-01-01

    This field guide to 100 economically or ecologically important tree species from Laos and Vietnam enables the user to identify the included taxa with user-friendly keys. It includes scientific names, botanical descriptions of families, genera, and species. Specific information on distribution,

  6. Equations relating compacted and uncompacted live crown ratio for common tree species in the South

    Science.gov (United States)

    KaDonna C. Randolph

    2010-01-01

    Species-specific equations to predict uncompacted crown ratio (UNCR) from compacted live crown ratio (CCR), tree length, and stem diameter were developed for 24 species and 12 genera in the southern United States. Using data from the US Forest Service Forest Inventory and Analysis program, nonlinear regression was used to model UNCR with a logistic function. Model...

  7. Intensive Selective Deer Browsing Favors Success of Asimina triloba (Paw Paw) a Native Tree Species

    Science.gov (United States)

    Mitchell A. Slater; Roger C. Anderson

    2014-01-01

    Although white-tailed deer (Odocoileus virginianus Zimmermann) are generalist herbivores, they can have significant effects on species composition and abundance of forest trees, especially when deer densities are high and most plant species are heavily browsed but a few are selectively avoided as browse. We evaluated effects of selective deer...

  8. Characterization of Arabidopsis Transcriptional Responses to Different Aphid Species Reveals Genes that Contribute to Host Susceptibility and Non-host Resistance

    Science.gov (United States)

    Jaouannet, Maëlle; Morris, Jenny A.; Hedley, Peter E.; Bos, Jorunn I. B.

    2015-01-01

    Aphids are economically important pests that display exceptional variation in host range. The determinants of diverse aphid host ranges are not well understood, but it is likely that molecular interactions are involved. With significant progress being made towards understanding host responses upon aphid attack, the mechanisms underlying non-host resistance remain to be elucidated. Here, we investigated and compared Arabidopsis thaliana host and non-host responses to aphids at the transcriptional level using three different aphid species, Myzus persicae, Myzus cerasi and Rhopalosiphum pisum. Gene expression analyses revealed a high level of overlap in the overall gene expression changes during the host and non-host interactions with regards to the sets of genes differentially expressed and the direction of expression changes. Despite this overlap in transcriptional responses across interactions, there was a stronger repression of genes involved in metabolism and oxidative responses specifically during the host interaction with M. persicae. In addition, we identified a set of genes with opposite gene expression patterns during the host versus non-host interactions. Aphid performance assays on Arabidopsis mutants that were selected based on our transcriptome analyses identified novel genes contributing to host susceptibility, host defences during interactions with M. persicae as well to non-host resistance against R. padi. Understanding how plants respond to aphid species that differ in their ability to infest plant species, and identifying the genes and signaling pathways involved, is essential for the development of novel and durable aphid control in crop plants. PMID:25993686

  9. Characterization of Arabidopsis Transcriptional Responses to Different Aphid Species Reveals Genes that Contribute to Host Susceptibility and Non-host Resistance.

    Directory of Open Access Journals (Sweden)

    Maëlle Jaouannet

    2015-05-01

    Full Text Available Aphids are economically important pests that display exceptional variation in host range. The determinants of diverse aphid host ranges are not well understood, but it is likely that molecular interactions are involved. With significant progress being made towards understanding host responses upon aphid attack, the mechanisms underlying non-host resistance remain to be elucidated. Here, we investigated and compared Arabidopsis thaliana host and non-host responses to aphids at the transcriptional level using three different aphid species, Myzus persicae, Myzus cerasi and Rhopalosiphum pisum. Gene expression analyses revealed a high level of overlap in the overall gene expression changes during the host and non-host interactions with regards to the sets of genes differentially expressed and the direction of expression changes. Despite this overlap in transcriptional responses across interactions, there was a stronger repression of genes involved in metabolism and oxidative responses specifically during the host interaction with M. persicae. In addition, we identified a set of genes with opposite gene expression patterns during the host versus non-host interactions. Aphid performance assays on Arabidopsis mutants that were selected based on our transcriptome analyses identified novel genes contributing to host susceptibility, host defences during interactions with M. persicae as well to non-host resistance against R. padi. Understanding how plants respond to aphid species that differ in their ability to infest plant species, and identifying the genes and signaling pathways involved, is essential for the development of novel and durable aphid control in crop plants.

  10. Frost hardiness of tree species is independent of phenology and ...

    Indian Academy of Sciences (India)

    Keywords. Biogeography; bud burst; LT50 ; macroclimatic niche; spring frost. Abstract. The differences in timing in bud burst between species have been interpreted as an adaptation to late frost events in spring. Thus, it has been suggested that the degree of frost susceptibility of leaves is species-specific and depends on ...

  11. Spectral reflectance of five hardwood tree species in southern Indiana

    Science.gov (United States)

    Dale R. Weigel; J.C. Randolph

    2013-01-01

    The use of remote sensing to identify forest species has been ongoing since the launch of Landsat-1 using MSS imagery. The ability to separate hardwoods from conifers was accomplished by the 1980s. However, distinguishing individual hardwood species is more problematic due to similar spectral and phenological characteristics. With the launch of commercial satellites...

  12. Long-term changes of tree species composition and distribution in Korean mountain forests

    Science.gov (United States)

    Lee, Boknam; Lee, Hoontaek; Cho, Sunhee; Yoon, Jongguk; Park, Jongyoung; Kim, Hyun Seok

    2017-04-01

    Long-term changes in the abundance and distribution of tree species in the temperate forests of South Korea remain poorly understood. We investigated how tree species composition and stand distribution change across temperate mountainous forests using the species composition and DBH size collected over the past 15 years (1998-2012) across 130 permanent forest plots of 0.1 ha in Jiri and Baegun mountains in South Korea. The overall net change of tree communities over the years showed positive in terms of stand density, richness, diversity, and evenness. At the species level, the change of relative species composition has been led by intermediate and shade-tolerant species, such as Quercus mongolica, Carpinus laxiflora, Quercus serrate, Quercus variabilis, Styrax japonicus, Lindera erythrocarpa, and Pinus densiflora and was categorized into five species communities, representing gradual increase or decrease, establishment, extinction, fluctuation of species population. At the community level, the change in species composition appeared to have consistent and directional patterns of increase in the annual rate of change in the mean species traits including species density, pole growth rate, adult growth rate, and adult stature. Based on the additive models, the distribution of species diversity was significantly related to topographical variables including elevation, latitude, longitude, slope, topographic wetness index, and curvature where elevation was the most significant driver, followed by latitude and longitude. However, the change in distribution of species diversity was only significantly influenced by latitude and longitude. This is the first study to reveal the long-term dynamics of change in tree species composition and distribution, which are important to broaden our understanding of temperate mountainous forest ecosystem in South Korea.

  13. Spatial distribution and interspecific associations of tree species in a tropical seasonal rain forest of China.

    Directory of Open Access Journals (Sweden)

    Guoyu Lan

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

  14. Host-parasite interactions: Marine bivalve molluscs and protozoan parasites, Perkinsus species.

    Science.gov (United States)

    Soudant, Philippe; E Chu, Fu-Lin; Volety, Aswani

    2013-10-01

    This review assesses and examines the work conducted to date concerning host and parasite interactions between marine bivalve molluscs and protozoan parasites, belonging to Perkinsus species. The review focuses on two well-studied host-parasite interaction models: the two clam species, Ruditapes philippinarum and R. decussatus, and the parasite Perkinsus olseni, and the eastern oyster, Crassostrea virginica, and the parasite Perkinsus marinus. Cellular and humoral defense responses of the host in combating parasitic infection, the mechanisms (e.g., antioxidant enzymes, extracellular products) employed by the parasite in evading host defenses as well as the role of environmental factors in modulating the host-parasite interactions are described. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-15

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

  16. Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions.

    Science.gov (United States)

    Loranger, Hannah; Zotz, Gerhard; Bader, Maaike Y

    2016-01-01

    On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, tree species ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline tree populations and will depend differently on climatic conditions than adult trees. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline tree species were studied: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata and Sorbus aucuparia In addition, we monitored the germination response of three of these species to low temperatures under controlled conditions in growth chambers. The early establishment of these trees at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly species-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each species. We show that temperature and water availability are both important contributors to establishment patterns of treeline trees and hence to species-specific forms and positions of alpine treelines. The observed idiosyncratic species responses highlight the need for studies including several species and life-stages to create predictive power concerning future treeline dynamics. © The Authors 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

  17. No Effect of Host Species on Phenoloxidase Activity in a Mycophagous Beetle.

    Directory of Open Access Journals (Sweden)

    Vincent Formica

    Full Text Available Ecological immunology is an interdisciplinary field that helps elucidate interactions between the environment and immune response. The host species individuals experience have profound effects on immune response in many species of insects. However, this conclusion comes from studies of herbivorous insects even though species of mycophagous insects also inhabit many different host species. The goal of this study was to determine if fungal host species as well as individual, sex, body size, and host patch predict one aspect of immune function, phenoloxidase activity (PO. We sampled a metapopulation of Bolitotherus cornutus, a mycophagous beetle in southwestern Virginia. B. cornutus live on three species of fungus that differ in nutritional quality, social environment, and density. A filter paper phenoloxidase assay was used to quantify phenoloxidase activity. Overall, PO activity was significantly repeatable among individuals (0.57 in adult B. cornutus. While there was significant variance among individuals in PO activity, there were surprisingly no significant differences in PO activity among subpopulations, beetles living on different host species, or between the sexes; there was also no effect of body size. Our results suggest that other factors such as age, genotype, disease prevalence, or natal environment may be generating variance among individuals in PO activity.

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

    Science.gov (United States)

    Jin, Yi; Qian, Hong; Yu, Mingjian

    2015-01-01

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

  19. Do host species evolve a specific response to slave-making ants?

    Directory of Open Access Journals (Sweden)

    Delattre Olivier

    2012-12-01

    Full Text Available Abstract Background Social parasitism is an important selective pressure for social insect species. It is particularly the case for the hosts of dulotic (so called slave-making ants, which pillage the brood of host colonies to increase the worker force of their own colony. Such raids can have an important impact on the fitness of the host nest. An arms race which can lead to geographic variation in host defenses is thus expected between hosts and parasites. In this study we tested whether the presence of a social parasite (the dulotic ant Myrmoxenus ravouxi within an ant community correlated with a specific behavioral defense strategy of local host or non-host populations of Temnothorax ants. Social recognition often leads to more or less pronounced agonistic interactions between non-nestmates ants. Here, we monitored agonistic behaviors to assess whether ants discriminate social parasites from other ants. It is now well-known that ants essentially rely on cuticular hydrocarbons to discriminate nestmates from aliens. If host species have evolved a specific recognition mechanism for their parasite, we hypothesize that the differences in behavioral responses would not be fully explained simply by quantitative dissimilarity in cuticular hydrocarbon profiles, but should also involve a qualitative response due to the detection of particular compounds. We scaled the behavioral results according to the quantitative chemical distance between host and parasite colonies to test this hypothesis. Results Cuticular hydrocarbon profiles were distinct between species, but host species did not show a clearly higher aggression rate towards the parasite than toward non-parasite intruders, unless the degree of response was scaled by the chemical distance between intruders and recipient colonies. By doing so, we show that workers of the host and of a non-host species in the parasitized site displayed more agonistic behaviors (bites and ejections towards parasite

  20. Discrimination of Deciduous Tree Species from Time Series of Unmanned Aerial System Imagery.

    Science.gov (United States)

    Lisein, Jonathan; Michez, Adrien; Claessens, Hugues; Lejeune, Philippe

    2015-01-01

    Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at tree level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS) should be used in order to efficiently discriminate deciduous tree species. The goal of this research is to determine when is the best time window to achieve an optimal species discrimination. A time series of high resolution UAS imagery was collected to cover the growing season from leaf flush to leaf fall. Full benefit was taken of the temporal resolution of UAS acquisition, one of the most promising features of small drones. The disparity in forest tree phenology is at the maximum during early spring and late autumn. But the phenology state that optimized the classification result is the one that minimizes the spectral variation within tree species groups and, at the same time, maximizes the phenologic differences between species. Sunlit tree crowns (5 deciduous species groups) were classified using a Random Forest approach for monotemporal, two-date and three-date combinations. The end of leaf flushing was the most efficient single-date time window. Multitemporal datasets definitely improve the overall classification accuracy. But single-date high resolution orthophotomosaics, acquired on optimal time-windows, result in a very good classification accuracy (overall out of bag error of 16%).

  1. Discrimination of Deciduous Tree Species from Time Series of Unmanned Aerial System Imagery.

    Directory of Open Access Journals (Sweden)

    Jonathan Lisein

    Full Text Available Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at tree level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS should be used in order to efficiently discriminate deciduous tree species. The goal of this research is to determine when is the best time window to achieve an optimal species discrimination. A time series of high resolution UAS imagery was collected to cover the growing season from leaf flush to leaf fall. Full benefit was taken of the temporal resolution of UAS acquisition, one of the most promising features of small drones. The disparity in forest tree phenology is at the maximum during early spring and late autumn. But the phenology state that optimized the classification result is the one that minimizes the spectral variation within tree species groups and, at the same time, maximizes the phenologic differences between species. Sunlit tree crowns (5 deciduous species groups were classified using a Random Forest approach for monotemporal, two-date and three-date combinations. The end of leaf flushing was the most efficient single-date time window. Multitemporal datasets definitely improve the overall classification accuracy. But single-date high resolution orthophotomosaics, acquired on optimal time-windows, result in a very good classification accuracy (overall out of bag error of 16%.

  2. Nutrition facts and limits for micronutrients in tree species used in urban forestry.

    Science.gov (United States)

    Brun, Flávia G K; Brun, Eleandro J; Gerber, Dionatan; Szymczak, Denise A; Londero, Eduardo K; Meyer, Evandro A; Navroski, Márcio C

    2017-01-01

    There is a huge lack of researches that evaluate the nutritional limits in tree species used in urban forestry, especially in terms of micronutrients. This study aimed to establish limits and range of micronutrients levels for the proper development of tree species utilized in urban forestry. The study was conducted in the city of Santa Maria-RS-Brazil. Through forest inventory, 23 forest species present in urban forest were selected, and 05 vegetative branches of each tree were collected, in which the contents of B, Cu, Fe, Mn and Zn were analyzed. Ranges of micronutrients' contents were developed for class limits criteria. Nutritional problems were detected for B, Cu and Zn in G. robusta and S. cumini, indicating a need of fertilization and management of these trees. The levels of Mn were within an adequate range only for the species C. illinoensis and H. chrysotrichus. The contents of B were higher than the level considered adequate for H. chrysotrichusand M. nigra. The rates of Fe showed high levels for E. japonica, H. chrysotrichusand S. babylonica. The estimated nutritional limits enable a greater control in the classification of the results for each tree species utilized in urban forestry.

  3. Tree species composition influences enzyme activities and microbial biomass in the rhizosphere: a rhizobox approach.

    Science.gov (United States)

    Fang, Shengzuo; Liu, Dong; Tian, Ye; Deng, Shiping; Shang, Xulan

    2013-01-01

    Monoculture causes nutrient losses and leads to declines in soil fertility and biomass production over successive cultivation. The rhizosphere, a zone of usually high microbial activities and clearly distinct from bulk soil, is defined as the volume of soil around living roots and influenced by root activities. Here we investigated enzyme activities and microbial biomass in the rhizosphere under different tree compositions. Six treatments with poplar, willow, and alder mono- or mixed seedlings were grown in rhizoboxes. Enzyme activities associated with nitrogen cycling and microbial biomass were measured in all rhizosphere and bulk soils. Both enzyme activities and microbial biomass in the rhizosphere differed significantly tree compositions. Microbial biomass contents were more sensitive to the changes of the rhizosphere environment than enzyme activities. Tree species coexistence did not consistently increase tested enzyme activities and microbial biomass, but varied depending on the complementarities of species traits. In general, impacts of tree species and coexistence were more pronounced on microbial composition than total biomass, evidenced by differences in microbial biomass C/N ratios stratified across the rhizosphere soils. Compared to poplar clone monoculture, other tree species addition obviously increased rhizosphere urease activity, but greatly reduced rhizosphere L-asparaginase activity. Poplar growth was enhanced only when coexisted with alder. Our results suggested that a highly productive or keystone plant species in a community had greater influence over soil functions than the contribution of diversity.

  4. Population Development of Several Species of Ants on the Cocoa Trees in South Sulawesi

    OpenAIRE

    Fatahuddin Fatahuddin; Ahdin Gassa; Junaidi Junaidi

    2010-01-01

    Several species of ants with different behavior have been found in cocoa plantations and their behavior is important to be considered because it might be correlated with the degree of protection of cocoa plant from cocoa pests. The aim of this research is to manipulate and to develop ants population in environment, so they are able to establish permanently in cocoa trees. This research was conducted in Papakaju Regions Luwu Regency in Juli to November 2009. In this study, 10 cocoa trees with ...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    between species and gene genealogies, as indicated by situations where conspecific individuals do not form a monophyletic cluster in a gene tree. In two previous reviews, non-monophyly has been reported as being common in mitochondrial DNA gene trees. We developed a novel web service "Monophylizer...... to their nearest neighbors or exceptionally high levels of intraspecific variability. Cases of polyphyly in COI trees arising as a result of deep intraspecific divergence are negligible, as the detected cases reflected misidentifications or methodological errors. Taking into consideration variation in sampling...

  6. Leaf anatomical traits of non-arboreal savanna species along a gradient of tree encroachment

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Souza Pinheiro

    2017-10-01

    Full Text Available ABSTRACT In the Brazilian savanna (Cerrado of Brazil, fire suppression has transformed typical savanna formations (TS into forested savanna (FS due to the phenomenon of encroachment. Under encroachment, non-arboreal plants begin to receive less light due to greater tree density and canopy closure. Here we aim to evaluate if leaf anatomical traits of non-arboreal species differ according to the degree of tree encroachment at the Assis Ecological Station - São Paulo, Brazil. To this end, we evaluated leaf tissue thickness and specific leaf area (SLA in representative non-arboreal species occurring along a gradient of tree encroachment. Leaves of TS species showed a trend towards xeromorphism, with traits reported to facilitate survival under high luminosity, such as thick leaves, thick epidermis and mesophyll, and low SLA. In contrast, FS species exhibited mesomorphic leaves, with thin mesophyll and high SLA, which are able to capture diffuse light in denser environments. Thus, non-arboreal understory species with mesomorphic leaf traits should be favored in environments with denser vegetation in contrast to typical savanna species. The results suggest that typical non-arboreal savanna species would not survive under tree encroachment due to the low competitiveness of their leaf anatomical strategies in shady environments.

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

    Science.gov (United States)

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

    2018-03-01

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

  8. BOREAS TE-04 Branch Bag Data from Boreal Tree Species

    Data.gov (United States)

    National Aeronautics and Space Administration — Contains 1996 TE-04 data of branch bag studies of photosynthesis, respiration and stomatal conductance of boreal forest species using the open MPH-1000 system.

  9. BOREAS TE-04 Branch Bag Data from Boreal Tree Species

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Contains 1996 TE-04 data of branch bag studies of photosynthesis, respiration and stomatal conductance of boreal forest species using the open MPH-1000...

  10. BOREAS TE-04 Gas Exchange Data from Boreal Tree Species

    Data.gov (United States)

    National Aeronautics and Space Administration — Contains TE-04 data on gas exchange studies of photosynthesis, respiration and stomatal conductance of boreal forest species using the MPH-1000 system.

  11. BOREAS TE-04 Gas Exchange Data from Boreal Tree Species

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Contains TE-04 data on gas exchange studies of photosynthesis, respiration and stomatal conductance of boreal forest species using the MPH-1000 system.

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

    Science.gov (United States)

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

    2017-10-28

    The diversity of forest trees as an indicator of ecosystem health can be assessed using the spectral characteristics of plant communities through remote sensing data. The objectives of this study were to investigate alpha and beta tree diversity using Landsat data for six dates in the Gönen dam watershed of Turkey. We used richness and the Shannon and Simpson diversity indices to calculate tree alpha diversity. We also represented the relationship between beta diversity and remotely sensed data using species composition similarity and spectral distance similarity of sampling plots via quantile regression. A total of 99 sampling units, each 20 m × 20 m, were selected using geographically stratified random sampling method. Within each plot, the tree species were identified, and all of the trees with a diameter at breast height (dbh) larger than 7 cm were measured. Presence/absence and abundance data (tree species number and tree species basal area) of tree species were used to determine the relationship between richness and the Shannon and Simpson diversity indices, which were computed with ground field data, and spectral variables derived (2 × 2 pixels and 3 × 3 pixels) from Landsat 8 OLI data. The Shannon-Weiner index had the highest correlation. For all six dates, NDVI (normalized difference vegetation index) was the spectral variable most strongly correlated with the Shannon index and the tree diversity variables. The Ratio of green to red (VI) was the spectral variable least correlated with the tree diversity variables and the Shannon basal area. In both beta diversity curves, the slope of the OLS regression was low, while in the upper quantile, it was approximately twice the lower quantiles. The Jaccard index is closed to one with little difference in both two beta diversity approaches. This result is due to increasing the similarity between the sampling plots when they are located close to each other. The intercept differences between two

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

    Science.gov (United States)

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

    2013-01-01

    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

  14. Phenotypic interactions between tree hosts and invasive forest pathogens in the light of globalization and climate change.

    Science.gov (United States)

    Stenlid, Jan; Oliva, Jonàs

    2016-12-05

    Invasive pathogens can cause considerable damage to forest ecosystems. Lack of coevolution is generally thought to enable invasive pathogens to bypass the defence and/or recognition systems in the host. Although mostly true, this argument fails to predict intermittent outcomes in space and time, underlining the need to include the roles of the environment and the phenotype in host-pathogen interactions when predicting disease impacts. We emphasize the need to consider host-tree imbalances from a phenotypic perspective, considering the lack of coevolutionary and evolutionary history with the pathogen and the environment, respectively. We describe how phenotypic plasticity and plastic responses to environmental shifts may become maladaptive when hosts are faced with novel pathogens. The lack of host-pathogen and environmental coevolution are aligned with two global processes currently driving forest damage: globalization and climate change, respectively. We suggest that globalization and climate change act synergistically, increasing the chances of both genotypic and phenotypic imbalances. Short moves on the same continent are more likely to be in balance than if the move is from another part of the world. We use Gremmeniella abietina outbreaks in Sweden to exemplify how host-pathogen phenotypic interactions can help to predict the impacts of specific invasive and emergent diseases.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

  15. Potential tree species for use in urban areas in temperate and oceanic climates

    Directory of Open Access Journals (Sweden)

    Miklas Scholz

    2016-09-01

    Full Text Available This study aims to assess the potential of trees for integration in urban development by evaluating the damage caused by trees in relation to various tree characteristics. Tree damage to permeable pavement systems and other urban structures such as impermeable pavements, kerbs, roads, retaining walls, footpaths, walls and buildings were assessed to identify the most suitable trees for the urban environment. One hundred square sites of 100 m × 100 m were randomly selected in Greater Manchester for this representative example case study to demonstrate the assessment methodology. Among tree species in this study, Acer platanoides L. (Norway maple occurred most frequently (17%; others were Tilia spp. L. (Lime; 16%, Fraxinus excelsior L. (common ash; 12%, Acer pseudoplatanus L. (sycamore; 10% and Prunus avium L. (wild cherry; 8%. The study concludes that 44% of the damage was to impermeable pavements and 22% to permeable pavements. Other damage to structures included kerbs (19%, retaining walls (5%, footpaths (4%, roads (3% and walls (3%. Concerning the severity of damage, 66% were moderate, 21% light and 19% severe. Aesculus hippocastanum L. (horse chestnut caused the greatest damage (59% expressed in percentage as a ratio of the tree number related to damage over the corresponding tree number that was found close to structures.

  16. Drivers of variation in species impacts for a multi-host fungal disease of bats.

    Science.gov (United States)

    Langwig, Kate E; Frick, Winifred F; Hoyt, Joseph R; Parise, Katy L; Drees, Kevin P; Kunz, Thomas H; Foster, Jeffrey T; Kilpatrick, A Marm

    2016-12-05

    Disease can play an important role in structuring species communities because the effects of disease vary among hosts; some species are driven towards extinction, while others suffer relatively little impact. Why disease impacts vary among host species remains poorly understood for most multi-host pathogens, and factors allowing less-susceptible species to persist could be useful in conserving highly affected species. White-nose syndrome (WNS), an emerging fungal disease of bats, has decimated some species while sympatric and closely related species have experienced little effect. We analysed data on infection prevalence, fungal loads and environmental factors to determine how variation in infection among sympatric host species influenced the severity of WNS population impacts. Intense transmission resulted in almost uniformly high prevalence in all species. By contrast, fungal loads varied over 3 orders of magnitude among species, and explained 98% of the variation among species in disease impacts. Fungal loads increased with hibernating roosting temperatures, with bats roosting at warmer temperatures having higher fungal loads and suffering greater WNS impacts. We also found evidence of a threshold fungal load, above which the probability of mortality may increase sharply, and this threshold was similar for multiple species. This study demonstrates how differences in behavioural traits among species-in this case microclimate preferences-that may have been previously adaptive can be deleterious after the introduction of a new pathogen. Management to reduce pathogen loads rather than exposure may be an effective way of reducing disease impact and preventing species extinctions.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

  17. Phylogenetic and chemotypic diversity of Periglandula species in eight new morning glory hosts (Convolvulaceae).

    Science.gov (United States)

    Beaulieu, Wesley T; Panaccione, Daniel G; Ryan, Katy L; Kaonongbua, Wittaya; Clay, Keith

    2015-01-01

    Periglandula ipomoeae and P. turbinae (Ascomycota, Clavicipitaceae) are recently described fungi that form symbiotic associations with the morning glories (Convolvulaceae) Ipomoea asarifolia and Turbina corymbosa, respectively. These Periglandula species are vertically transmitted and produce bioactive ergot alkaloids in seeds of infected plants and ephemeral mycelia on the adaxial surface of young leaves. Whether other morning glories that contain ergot alkaloids also are infected by Periglandula fungi is a central question. Here we report on a survey of eight species of Convolvulaceae (Argyreia nervosa, I. amnicola, I. argillicola, I. gracilis, I. hildebrandtii, I. leptophylla, I. muelleri, I. pes-caprae) for ergot alkaloids in seeds and associated clavicipitaceous fungi potentially responsible for their production. All host species contained ergot alkaloids in four distinct chemotypes with concentrations of 15.8-3223.0 μg/g. Each chemotype was a combination of four or five ergot alkaloids out of seven alkaloids detected across all hosts. In addition, each host species exhibited characteristic epiphytic mycelia on adaxial surfaces of young leaves with considerable interspecific differences in mycelial density. We sequenced three loci from fungi infecting each host: the nuclear rDNA internal transcribed spacer region (ITS), introns of the translation factor 1-α gene (tefA) and the dimethylallyl-tryptophan synthase gene (dmaW), which codes for the enzyme that catalyzes the first step in ergot alkaloid biosynthesis. Phylogenetic analyses confirmed that these fungi are in the family Clavicipitaceae and form a monophyletic group with the two described Periglandula species. This study is the first to report Periglandula spp. from Asian, Australian, African and North American species of Convolvulaceae, including host species with a shrub growth form and host species occurring outside of the tropics. This study demonstrates that ergot alkaloids in morning glories

  18. Object-Based Tree Species Classification in Urban Ecosystems Using LiDAR and Hyperspectral Data

    Directory of Open Access Journals (Sweden)

    Zhongya Zhang

    2016-06-01

    Full Text Available In precision forestry, tree species identification is key to evaluating the role of forest ecosystems in the provision of ecosystem services, such as carbon sequestration and assessing their effects on climate regulation and climate change. In this study, we investigated the effectiveness of tree species classification of urban forests using aerial-based HyMap hyperspectral imagery and light detection and ranging (LiDAR data. First, we conducted an object-based image analysis (OBIA to segment individual tree crowns present in LiDAR-derived Canopy Height Models (CHMs. Then, hyperspectral values for individual trees were extracted from HyMap data for band reduction through Minimum Noise Fraction (MNF transformation which allowed us to reduce the data to 20 significant bands out of 118 bands acquired. Finally, we compared several different classifications using Random Forest (RF and Multi Class Classifier (MCC methods. Seven tree species were classified using all 118 bands which resulted in 46.3% overall classification accuracy for RF versus 79.6% for MCC. Using only the 20 optimal bands extracted through MNF, both RF and MCC achieved an increase in overall accuracy to 87.0% and 88.9%, respectively. Thus, the MNF band selection process is a preferable approach for tree species classification when using hyperspectral data. Further, our work also suggests that RF is heavily disadvantaged by the high-dimensionality and noise present in hyperspectral data, while MCC is more robust when handling high-dimensional datasets with small sample sizes. Our overall results indicated that individual tree species identification in urban forests can be accomplished with the fusion of object-based LiDAR segmentation of crowns and hyperspectral characterization.

  19. Digenean parasites of Chinese marine fishes: a list of species, hosts and geographical distribution.

    Science.gov (United States)

    Liu, Sheng-fa; Peng, Wen-feng; Gao, Peng; Fu, Ming-jun; Wu, Han-zhou; Lu, Ming-ke; Gao, Ji-qing; Xiao, Jun

    2010-01-01

    In the literature, 630 species of Digenea (Trematoda) have been reported from Chinese marine fishes. These belong to 209 genera and 35 families. The names of these species, along with their hosts, geographical distribution and records, are listed in this paper.

  20. Genetic analysis of larval host-plant preference in two sibling species of Helicoverpa

    NARCIS (Netherlands)

    Tang, Q.B.; Jiang, J.W.; Yan, Y.H.; Loon, van J.J.A.; Wang, C.Z.

    2006-01-01

    The genetic basis of larval host-plant preference was investigated in reciprocal F1, F2, and backcrossed generations derived from hybrid crosses between the generalist species Helicoverpa armigera (Hu¿bner) and the closely related specialist species Helicoverpa assulta (Guene¿e) (Lepidoptera:

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

    OpenAIRE

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

    2013-01-01

    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 ...

  2. Proceedings of the fourth international workshop on the genetics of host-parasite interactions in forestry: Disease and insect resistance in forest trees

    Science.gov (United States)

    Richard A. Sniezko; Alvin D. Yanchuk; John T. Kliejunas; Katharine M. Palmieri; Janice M. Alexander; Susan J. Frankel

    2012-01-01

    Individual papers are available at http://www.fs.fed.us/psw/publications/documents/psw_gtr240/The Fourth International Workshop on the Genetics of Host-Parasite Interactions in Forestry: Disease and Insect Resistance in Forest Trees...

  3. How do PrPSc Prions Spread between Host Species, and within Hosts?

    Directory of Open Access Journals (Sweden)

    Neil A. Mabbott

    2017-11-01

    Full Text Available Prion diseases are sub-acute neurodegenerative diseases that affect humans and some domestic and free-ranging animals. Infectious prion agents are considered to comprise solely of abnormally folded isoforms of the cellular prion protein known as PrPSc. Pathology during prion disease is restricted to the central nervous system where it causes extensive neurodegeneration and ultimately leads to the death of the host. The first half of this review provides a thorough account of our understanding of the various ways in which PrPSc prions may spread between individuals within a population, both horizontally and vertically. Many natural prion diseases are acquired peripherally, such as by oral exposure, lesions to skin or mucous membranes, and possibly also via the nasal cavity. Following peripheral exposure, some prions accumulate to high levels within the secondary lymphoid organs as they make their journey from the site of infection to the brain, a process termed neuroinvasion. The replication of PrPSc prions within secondary lymphoid organs is important for their efficient spread to the brain. The second half of this review describes the key tissues, cells and molecules which are involved in the propagation of PrPSc prions from peripheral sites of exposure (such as the lumen of the intestine to the brain. This section also considers how additional factors such as inflammation and aging might influence prion disease susceptibility.

  4. How do PrPScPrions Spread between Host Species, and within Hosts?

    Science.gov (United States)

    Mabbott, Neil A

    2017-11-24

    Prion diseases are sub-acute neurodegenerative diseases that affect humans and some domestic and free-ranging animals. Infectious prion agents are considered to comprise solely of abnormally folded isoforms of the cellular prion protein known as PrP Sc . Pathology during prion disease is restricted to the central nervous system where it causes extensive neurodegeneration and ultimately leads to the death of the host. The first half of this review provides a thorough account of our understanding of the various ways in which PrP Sc prions may spread between individuals within a population, both horizontally and vertically. Many natural prion diseases are acquired peripherally, such as by oral exposure, lesions to skin or mucous membranes, and possibly also via the nasal cavity. Following peripheral exposure, some prions accumulate to high levels within the secondary lymphoid organs as they make their journey from the site of infection to the brain, a process termed neuroinvasion. The replication of PrP Sc prions within secondary lymphoid organs is important for their efficient spread to the brain. The second half of this review describes the key tissues, cells and molecules which are involved in the propagation of PrP Sc prions from peripheral sites of exposure (such as the lumen of the intestine) to the brain. This section also considers how additional factors such as inflammation and aging might influence prion disease susceptibility.

  5. Tree species traits cause divergence in soil acidification during four decades of postagricultural forest development

    DEFF Research Database (Denmark)

    Schrijver, An de; Frenne, Pieter de; Staelens, Jeroen

    2012-01-01

    and unequivocally drives postagricultural forests towards more acidic conditions, but the rate of soil acidification is also determined by the tree species-specific leaf litter quality and litter decomposition rates. We propose that the intrinsic differences in leaf litter quality among tree species create...... fundamentally different nutrient cycles within the ecosystem, both directly through the chemical composition of the litter and indirectly through its effects on the size and composition of earthworm communities. Poor leaf litter quality contributes to the absence of a burrowing earthworm community, which...... retards leaf litter decomposition and, consequently, results in forest-floor build-up and soil acidification. Also nutrient uptake and N2 fixation are causing soil acidification, but were found to be less important. Our results highlight the fact that tree species-specific traits significantly influence...

  6. THE IMPORTANCE OF USING FRUIT TREE SPECIES WITH ORNAMENTAL ROLE IN RUSTIC GARDENS LANDSCAPING

    Directory of Open Access Journals (Sweden)

    Roxana Negrea

    2012-04-01

    Full Text Available Ornamental fruit trees are suitable for rustic gardens, although "rustic" is translated to us especially by "poverty" or "obsolete", in much broader terms refers to "something else " meaning return to nature, respect, tradition and even a certain social status. It is therefore essential that in the woody vegetation campestre gardens to find rustic tree species, which by their habitus and color bring moredynamism and candor to any type of garden, especially rustic garden type. These species can be introduced into the composition either as individual parts or grups, decorating the trees in the same visualcharacter (class, habitus, foliage, flowers, also providing the desired fruit. The great advantage of these species is that in addition to their great capacity to make the area in which they are positioned beautiful, by the beauty of the flowers, leaves or even the different colors every season, offers real taste delights through the fruit they produce.

  7. REVIEW: Species Diversity of Local Fruit Trees in Kalimantan: Problems of Conservation and Its Development

    Directory of Open Access Journals (Sweden)

    MUSTAID SIREGAR

    2006-01-01

    Full Text Available The decrease in population of local fruit trees due to the forest destruction in some places in Kalimantan is a worrying trend.The genetic diversity of fruits in Kalimantan has been saved partly through indigenous agroforestry, as species cultivated from generation to generation by indigenous people have created miniature forests in the village agroecosystem. However, there is no doubt that the existence of local fruit trees has been threatened by the introduction of a superior fruit cultivars and other commercial plant species such as coconuts (Cocos nucifera, oil palm (Elaeis guinensis and rubber trees (Hevea braziliensis. An ex-situ conservation program is proposed for the maintenance of diversity amongst local fruit species.

  8. Influences of forest structure, climate and species composition on tree mortality across the eastern US.

    Directory of Open Access Journals (Sweden)

    Emily R Lines

    Full Text Available Few studies have quantified regional variation in tree mortality, or explored whether species compositional changes or within-species variation are responsible for regional patterns, despite the fact that mortality has direct effects on the dynamics of woody biomass, species composition, stand structure, wood production and forest response to climate change. Using bayesian analysis of over 430,000 tree records from a large eastern US forest database we characterised tree mortality as a function of climate, soils, species and size (stem diameter. We found (1 mortality is U-shaped vs. stem diameter for all 21 species examined; (2 mortality is hump-shaped vs. plot basal area for most species; (3 geographical variation in mortality is substantial, and correlated with several environmental factors; and (4 individual species vary substantially from the combined average in the nature and magnitude of their mortality responses to environmental variation. Regional variation in mortality is therefore the product of variation in species composition combined with highly varied mortality-environment correlations within species. The results imply that variation in mortality is a crucial part of variation in the forest carbon cycle, such that including this variation in models of the global carbon cycle could significantly narrow uncertainty in climate change predictions.

  9. Bacterial communities of diverse Drosophila species: ecological context of a host-microbe model system.

    Science.gov (United States)

    Chandler, James Angus; Lang, Jenna Morgan; Bhatnagar, Srijak; Eisen, Jonathan A; Kopp, Artyom

    2011-09-01

    Drosophila melanogaster is emerging as an important model of non-pathogenic host-microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal-microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host-microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host-microbe interactions. Bacterial taxa used in experimental studies are rare or absent in wild

  10. Bacterial communities of diverse Drosophila species: ecological context of a host-microbe model system.

    Directory of Open Access Journals (Sweden)

    James Angus Chandler

    2011-09-01

    Full Text Available Drosophila melanogaster is emerging as an important model of non-pathogenic host-microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal-microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host-microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host-microbe interactions. Bacterial taxa used in experimental studies are rare

  11. Molecular approaches identify known species, reveal cryptic species and verify host specificity of Chinese Philotrypesis (Hymenoptera: Pteromalidae).

    Science.gov (United States)

    Zhou, Mei-Jiao; Xiao, Jin-Hua; Bian, Sheng-Nan; Li, Yan-Wei; Niu, Li-Ming; Hu, Hao-Yuan; Wu, Wen-Shan; Murphy, Robert W; Huang, Da-Wei

    2012-07-01

    Philotrypesis, a major component of the fig wasp community (Hymenoptera: Pteromalidae), is a model taxon for studying male fighting and mating behaviour. Its extreme sexual dimorphism and male polymorphism render species identification uncertain and in-depth research on its ecology, behaviour and other evolutionary topics challenging. The fig wasps' enclosed habitat within the syconia makes their mating behaviour inaccessible, to the extent of matching conspecific females and males. In this study, we combine morphological and molecular analyses to identify species of Philotrypesis sampled from south China and to associate their extraordinarily dimorphic genders and labile male morphologies. Morphological evaluations of females identify 22 species and 28 male morphs. The mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2 data detect 21 species using females, and 15 species among the males. Most of the males match the species as delimited by females. Both markers reveal cryptic species in P. quadrisetosa on Ficus vasculosa. Most species of wasps live on one species of fig but three species co-occur in two hosts (F. microcarpa and F. benjamina), which indicates host switching. © 2012 Blackwell Publishing Ltd.

  12. Separation of the bioclimatic spaces of Himalayan tree rhododendron species predicted by ensemble suitability models

    Directory of Open Access Journals (Sweden)

    Sailesh Ranjitkar

    2014-08-01

    Full Text Available The tree rhododendrons include the most widely distributed Himalayan Rhododendron species belonging to the subsection Arborea. Distributions of two members of this sub-species were modelled using bioclimatic data for current conditions (1950–2000. A subset of the least correlated bioclimatic variables was used for ecological niche modelling (ENM. We used an ENM ensemble method in the BiodiversityR R-package to map the suitable climatic space for tree rhododendrons based on 217 point location records. Ensemble bioclimatic models for tree rhododendrons had high predictive power with bioclimatic variables, which also separated the climatic spaces for the two species. Tree rhododendrons were found occurring in a wide range of climate and the distributional limits were associated with isothermality, temperature ranges, temperature of the wettest quarter, and precipitation of the warmest quarter of the year. The most suitable climatic space for tree rhododendrons was predicted to be in western Yunnan, China, with suitability declining towards the west and east. Its occurrence in a wide range of climatic settings with highly dissected habitats speaks to the adaptive capacity of the species, which might open up future options for their conservation planning in regions where they are listed as threatened.

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Science.gov (United States)

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

    2012-07-01

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

  15. Tree Species Richness, Diversity, and Vegetation Index for Federal Capital Territory, Abuja, Nigeria

    Directory of Open Access Journals (Sweden)

    Aladesanmi D Agbelade

    2017-01-01

    Full Text Available This study was conducted to investigate the tree species richness and diversity of urban and periurban areas of the Federal Capital Territory (FCT, Abuja, Nigeria, and produce Normalized Difference Vegetation Index (NDVI for the territory. Data were collected from urban (Abuja city and periurban (Lugbe areas of the FCT using both semistructured questionnaire and inventory of tree species within green areas. In the study location, all trees with diameter at breast height (dbh ≥ 10 cm were identified; their dbh was measured and frequency was taken. The NDVI was calculated in ArcGIS 10.3 environment using standard formula. A cumulative total of twenty-nine (29 families were encountered within the FCT, with 27 occurring in Abuja city (urban centre and 12 in Lugbe (periurban centre of the FCT. The results of Shannon-Wiener diversity index (H′ for the two centres are 3.56 and 2.24 while Shannon’s maximum diversity index (Hmax is 6.54 (Abuja city and 5.36 (Lugbe for the urban (Abuja city and periurban (Lugbe areas of the Federal Capital Territory (FCT. The result of tree species evenness (Shannon’s equitability (EH index in urban and periurban centres was 0.54 and 0.42, respectively. The study provided baseline information on urban and periurban forests in the FCT of Nigeria, which can be used for the development of tree species database of the territory.

  16. Floristics of mangrove tree species in Angke-Kapuk Protected Forest

    Directory of Open Access Journals (Sweden)

    RUGAYAH

    2005-01-01

    Full Text Available Angke-Kapuk Protected Forest with total area 44.76 ha is part of the Tegal Alur-Angke Kapuk mangrove forests. Therefore, this forest has important role as an interface between terrestrial and marine ecosystems, whether physical, biological or social-economic aspects, to determine mangrove ecosystem as a productive and unique ecosystem in the coastal area. However, the study of floristic of the mangrove vegetation in this forest has never to be done previously. According to the study on September to November 2003, in this forest found 8 species of mangrove trees. The tree species can be classified into two groups. The first group is true mangroves (7 species, i.e. Avicennia officinalis, Rhizophora apiculata, R. mucronata, R. stylosa, Sonneratia caseolaris (major component, Excoecaria agallocha, and Xylocarpus moluccensis (minor component. The last group is mangrove associate, i.e. Terminalia catappa. In this forest also found 7 tree species, i.e. Bruguiera gymnorrhiza, Calophyllum inophyllum, Cerbera manghas, Paraserianthes falcataria, Tamarindus indicus, Acacia mangium, and A. auriculiformis as introduced species. The growth level of B. gymnorhiza, C. inophyllum and C. manghas up to now is seedling and sapling, while the growth level of another introduced species is till in pole and tree.

  17. ECOLOGICAL CONDITIONS AND DISTRIBUTION OF GEMOR TREE SPECIES IN CENTRAL AND EAST KALIMANTAN

    Directory of Open Access Journals (Sweden)

    Wahyu C. Adinugroho

    2011-06-01

    Full Text Available The aim of this study was to determine the ecological conditions and distribution of gemor bark producing tree species at Tuanan village in Kapuas District, Central Kalimantan Province and Long Daliq village in Kutai Barat, East Kalimantan Province. In order to collect adequate vegetation data, several obser vation plots were laid out by using purposive sampling. Primary and secondary data were collected from the plot areas by obser ving directly the habitat and its ecological condition of vegetation. It was revealed that the gemor tree species tended to grow well on the habitats which have a thin layer of peat (< 2 m, pH 3 – 4 and in a humid climatic condition.  Two gemor bark producing tree species were identidfied in the study areas, namely Nothaphoebe coriacea (Kosterm. Kosterm. and  N. umbelliflora Blume. The similarity level of vegetation composition at both sites (Kapuas and Kutai Barat Districts was low. The tree species richness in the plot areas of Tuanan in Kapuas District, Central Kalimantan (82 species, 57 genera and 28 families was higher than that found in Long Daliq, Kutai Barat District, East Kalimantan (38 species, 26 genera and 19 families.

  18. Forest Management Influences Aboveground Carbon and Tree Species Diversity in Myanmar’s Mixed Deciduous Forests

    Directory of Open Access Journals (Sweden)

    Kyaw Sein Win Tun

    2016-09-01

    Full Text Available Declines in the global extent and condition of tropical forests have reduced carbon storage potential and caused biodiversity loss. However, the magnitude of these problems within individual countries may depend on the extent of the reserved forest estate, and the particular rules put in place to manage resource use in these areas. To test this hypothesis, aboveground carbon stocks and indices of tree diversity were derived for two reserved (highly regulated sites and a protected public (less regulated site in the mixed deciduous forests of Myanmar. Aboveground tree carbon stocks were around three times higher in the reserved forests than in the public forest, a difference driven by the near absence of trees >40 cm DBH at the public forest site. The species composition of large (≥20 cm DBH trees differed substantially between all three sites. In contrast, the species composition of small (<20 cm DBH trees differed between the reserved and public forest in the case of one reserved site but not the other. Both species richness and diversity of large (≥20 cm DBH trees was about five times higher in the reserved forest than in the public forest. This was not the case for small (<20 cm DBH trees, where estimates of both richness and diversity were similar at all three sites. These findings suggest that both carbon storage potential and large-tree diversity are influenced by forest protection status. This has important implications for national carbon storage estimates as forest protection status is not currently considered as part of the standard carbon accounting procedure.

  19. Climate driven range divergence among host species affects range-wide patterns of parasitism

    Directory of Open Access Journals (Sweden)

    Richard E. Feldman

    2017-01-01

    Full Text Available Species interactions like parasitism influence the outcome of climate-driven shifts in species ranges. For some host species, parasitism can only occur in that part of its range that overlaps with a second host species. Thus, predicting future parasitism may depend on how the ranges of the two hosts change in relation to each other. In this study, we tested whether the climate driven species range shift of Odocoileus virginianus (white-tailed deer accounts for predicted changes in parasitism of two other species from the family Cervidae, Alces alces (moose and Rangifer tarandus (caribou, in North America. We used MaxEnt models to predict the recent (2000 and future (2050 ranges (probabilities of occurrence of the cervids and a parasite Parelaphostrongylus tenuis (brainworm taking into account range shifts of the parasite’s intermediate gastropod hosts. Our models predicted that range overlap between A. alces/R. tarandus and P. tenuis will decrease between 2000 and 2050, an outcome that reflects decreased overlap between A. alces/R. tarandus and O. virginianus and not the parasites, themselves. Geographically, our models predicted increasing potential occurrence of P. tenuis where A. alces/R. tarandus are likely to decline, but minimal spatial overlap where A. alces/R. tarandus are likely to increase. Thus, parasitism may exacerbate climate-mediated southern contraction of A. alces and R. tarandus ranges but will have limited influence on northward range expansion. Our results suggest that the spatial dynamics of one host species may be the driving force behind future rates of parasitism for another host species.

  20. [Biomass allometric equations of nine common tree species in an evergreen broadleaved forest of subtropical China].

    Science.gov (United States)

    Zuo, Shu-di; Ren, Yin; Weng, Xian; Ding, Hong-feng; Luo, Yun-jian

    2015-02-01

    Biomass allometric equation (BAE) considered as a simple and reliable method in the estimation of forest biomass and carbon was used widely. In China, numerous studies focused on the BAEs for coniferous forest and pure broadleaved forest, and generalized BAEs were frequently used to estimate the biomass and carbon of mixed broadleaved forest, although they could induce large uncertainty in the estimates. In this study, we developed the species-specific and generalized BAEs using biomass measurement for 9 common broadleaved trees (Castanopsis fargesii, C. lamontii, C. tibetana, Lithocarpus glaber, Sloanea sinensis, Daphniphyllum oldhami, Alniphyllum fortunei, Manglietia yuyuanensis, and Engelhardtia fenzlii) of subtropical evergreen broadleaved forest, and compared differences in species-specific and generalized BAEs. The results showed that D (diameter at breast height) was a better independent variable in estimating the biomass of branch, leaf, root, aboveground section and total tree than a combined variable (D2 H) of D and H (tree height) , but D2H was better than D in estimating stem biomass. R2 (coefficient of determination) values of BAEs for 6 species decreased when adding H as the second independent variable into D- only BAEs, where R2 value for S. sinensis decreased by 5.6%. Compared with generalized D- and D2H-based BAEs, standard errors of estimate (SEE) of BAEs for 8 tree species decreased, and similar decreasing trend was observed for different components, where SEEs of the branch decreased by 13.0% and 20.3%. Therefore, the biomass carbon storage and its dynamic estimates were influenced largely by tree species and model types. In order to improve the accuracy of the estimates of biomass and carbon, we should consider the differences in tree species and model types.

  1. Vegetative propagation of twelve fodder tree species indigenous to ...

    African Journals Online (AJOL)

    ... Commiphora africana, Faidherbia albida, Ficus gnaphalocarpa, Guiera senegalensis, Kigelia africana, Pterocarpus erinaceus, Pterocarpus lucens, Pterocarpus santalinoides and Terminalia avicennioides. The series also evaluated the impacts of the size (a. africanantalinoides was revealed to be an easy-to-root species, ...

  2. Effect of Multipurpose Tree Species on Soil Fauna and Weed ...

    African Journals Online (AJOL)

    ... cordifolia / Gliricidia sepium / Dactyladenia barterii / Leucaenia leucocephala < natural fallow. Similarly, soil fauna increased more in the multipurpose woody species than in natural fallow. Recommendations based on the high weed suppressing ability, good litter formation and low soil nematode diversity were address.

  3. Within- and between- class variability of spectrally similar tree species

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2009-07-01

    Full Text Available In this paper, a comparison is made through evaluating the within and between-class species variability for the original, the first derivative and second derivative spectra. For each, the experiment was conducted (i) over the entire electromagnetic...

  4. Rubisco activity and gene expression of tropical tree species under ...

    African Journals Online (AJOL)

    Tropical rain forests contain an ecologically and physiologically diverse range of vegetation and habitats. Sun-acclimated plants can be divided into two groups, shade-tolerant and shade-intolerant, according to the plant's physiological and genetic responses. Some tropical species have potential capacity for light damage ...

  5. Residential Knowledge of Native Tree Species: A Case Study of Residents in Four Southern Ontario Municipalities

    Science.gov (United States)

    Almas, Andrew D.; Conway, Tenley M.

    2017-01-01

    In the past decade, municipalities across North America have increased investment in their urban forests in an effort to maintain and enhance the numerous benefits provided by them. Some municipalities have now drafted long-term urban forest management plans that emphasize the planting of native trees, to improve ecological integrity, and participation of residents, since the majority of urban trees are typically located on residential property. Yet it is unclear if residents are familiar with native trees or municipalities' urban forest management goals. Through a case study of southern Ontario municipalities, we administered a survey exploring residents' ability to correctly label common tree species as native or non-native, as well as their knowledge of urban forest management plans to test four hypotheses: 1) residents in municipalities with an urban forest management plans will be more knowledgeable about the native status of common street trees; 2) residents who have lived in the area longer will have greater knowledge; 3) knowledge level will be correlated with education level, ethnicity, and income; and 4) residents' knowledge will be related to having planted trees on their property. Our results indicate that residents are better able to identify common native trees than correctly determine which trees are non-native, although knowledge levels are generally low. Knowledge was significantly related to length of residency and tree planting experience, supporting hypotheses 2 and 4. These results highlight the importance of experience and local knowledge acquisition in relation to basic knowledge about urban trees, and also point to the failures of resident outreach within the case study municipalities.

  6. Invasive North American bullfrogs transmit lethal fungus Batrachochytrium dendrobatidis infections to native amphibian host species

    OpenAIRE

    Miaud, C.; Dejean, T.; Savard, K.; Millery, A.; Valentini, A.; Gaudin, N. C. G.; Garner, T. W. J.

    2016-01-01

    Invasive species can be a threat to native species in several ways, including transmitting lethal infections caused by the parasites they carry. However, invasive species may also be plagued by novel and lethal infections they acquire when invading, making inferences regarding the ability of an invasive host to vector disease difficult from field observations of infection and disease. This is the case for the pathogenic fungus Batrachochytrium dendrobatidis (Bd) in Europe and one invasive hos...

  7. Frequent Cross-Species Transmission of Parvoviruses among Diverse Carnivore Hosts

    OpenAIRE

    Allison, Andrew B.; Kohler, Dennis J.; Fox, Karen A.; Brown, Justin D.; Gerhold, Richard W.; Shearn-Bochsler, Valerie I.; Dubovi, Edward J.; Parrish, Colin R.; Holmes, Edward C.

    2013-01-01

    Although parvoviruses are commonly described in domestic carnivores, little is known about their biodiversity in nondomestic species. A phylogenetic analysis of VP2 gene sequences from puma, coyote, gray wolf, bobcat, raccoon, and striped skunk revealed two major groups related to either feline panleukopenia virus (“FPV-like”) or canine parvovirus (“CPV-like”). Cross-species transmission was commonplace, with multiple introductions into each host species but, with the exception of raccoons, r...

  8. Global correlations in tropical tree species richness and abundance reject neutrality.

    Science.gov (United States)

    Ricklefs, Robert E; Renner, Susanne S

    2012-01-27

    Patterns of species richness and relative abundance at some scales cannot be distinguished from predictions of null models, including zero-sum neutral models of population change and random speciation-extinction models of evolutionary diversification. Both models predict that species richness or population abundance produced by independent iterations of the same processes in different regions should be uncorrelated. We find instead that the number of species and individuals in families of trees in forest plots are strongly correlated across Southeast Asia, Africa, and tropical America. These correlations imply that deterministic processes influenced by evolutionarily conservative family-level traits constrain the number of confamilial tree species and individuals that can be supported in regional species pools and local assemblages in humid tropical forests.

  9. How tree species fill geographic and ecological space in eastern North America.

    Science.gov (United States)

    Ricklefs, Robert E

    2015-05-01

    Ecologists broadly accept that the number of species present within a region balances regional processes of immigration and speciation against competitive and other interactions between populations that limit distribution and constrain diversity. Although ecological theory has, for a long time, addressed the premise that ecological space can be filled to 'capacity' with species, only with the availability of time-calibrated phylogenies has it been possible to test the hypothesis that diversification slows as the number of species in a region increases. Focusing on the deciduous trees of eastern North America, this study tested predictions from competition theory concerning the distribution and abundance of species. Local assemblages of trees tabulated in a previous study published in 1950 were analysed. Assemblages were ordinated with respect to species composition by non-metric multidimensional scaling (NMS). Distributions of trees were analysed by taxonomically nested analysis of variance, discriminant analysis based on NMS scores, and canonical correlation analysis of NMS scores and Bioclim climate variables. Most of the variance in species abundance and distribution was concentrated among closely related (i.e. congeneric) species, indicating evolutionary lability. Species distribution and abundance were unrelated to the number of close relatives, suggesting that competitive effects are diffuse. Distances between pairs of congeneric species in NMS space did not differ significantly from distances between more distantly related species, in contrast to the predictions of both competitive habitat partitioning and ecological sorting of species. Eastern deciduous forests of North America do not appear to be saturated with species. The distributions and abundances of individual species provide little evidence of being shaped by competition from related (i.e. ecologically similar) species and, by inference, that diversification is constrained by interspecific

  10. The right tree for the job? perceptions of species suitability for the provision of ecosystem services.

    Science.gov (United States)

    Smaill, Simeon J; Bayne, Karen M; Coker, Graham W R; Paul, Thomas S H; Clinton, Peter W

    2014-04-01

    Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate tree species possessed those attributes. These data were combined to identify the species perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate species. Stakeholder perceptions substantially influence tree species selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services.

  11. Effects of Drought and Rewetting on Growth and Gas Exchange of Minor European Broadleaved Tree Species

    Directory of Open Access Journals (Sweden)

    Jörg Kunz

    2016-10-01

    Full Text Available Widespread and economically important European tree species such as Norway spruce, Scots pine, and European beech are projected to be negatively affected by the increasing intensity and frequency of dry and hot conditions in a future climate. Hence, there is an increasing need to investigate the suitability of presumably more drought tolerant species to ensure future ecological stability, biodiversity, and productivity of forests. Based on their distribution patterns and climatic envelopes, the rare, minor broadleaved tree species Sorbus torminalis ((L. CRANTZ, S. domestica (L., Acer campestre (L., and A. platanoides (L. are assumed to be drought tolerant, however, there is only limited experimental basis to support that notion. This study aimed at quantifying growth and gas exchange of seedlings of these species during drought conditions, and their capacity to recover following drought. For that purpose, they were compared to the common companion species Quercus petraea ((MATTUSCHKA LIEBL. and Fagus sylvatica (L.. Here, potted seedlings of these species were exposed to water limitation followed by rewetting cycles in a greenhouse experiment. Photosynthesis and transpiration rates, stomatal conductance as well as root and shoot growth rates indicated a high drought resistance of A. campestre and A. platanoides. Sorbus domestica showed a marked ability to recover after drought stress. Therefore, we conclude that these minor tree species have the potential to enrich forests on drought-prone sites. Results from this pot experiment need to be complemented by field studies, in which the drought response of the species is not influenced by restrictions to root development.

  12. The Right Tree for the Job? Perceptions of Species Suitability for the Provision of Ecosystem Services

    Science.gov (United States)

    Smaill, Simeon J.; Bayne, Karen M.; Coker, Graham W. R.; Paul, Thomas S. H.; Clinton, Peter W.

    2014-04-01

    Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate tree species possessed those attributes. These data were combined to identify the species perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate species. Stakeholder perceptions substantially influence tree species selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services.

  13. Tree cover at fine and coarse spatial grains interacts with shade tolerance to shape plant species distributions across the Alps.

    Science.gov (United States)

    Nieto-Lugilde, Diego; Lenoir, Jonathan; Abdulhak, Sylvain; Aeschimann, David; Dullinger, Stefan; Gégout, Jean-Claude; Guisan, Antoine; Pauli, Harald; Renaud, Julien; Theurillat, Jean-Paul; Thuiller, Wilfried; Van Es, Jérémie; Vittoz, Pascal; Willner, Wolfgang; Wohlgemuth, Thomas; Zimmermann, Niklaus E; Svenning, Jens-Christian

    2015-06-01

    The role of competition for light among plants has long been recognised at local scales, but its importance for plant species distributions at larger spatial scales has generally been ignored. Tree cover modifies the local abiotic conditions below the canopy, notably by reducing light availability, and thus, also the performance of species that are not adapted to low-light conditions. However, this local effect may propagate to coarser spatial grains, by affecting colonisation probabilities and local extinction risks of herbs and shrubs. To assess the effect of tree cover at both the plot- and landscape-grain sizes (approximately 10-m and 1-km), we fit Generalised Linear Models (GLMs) for the plot-level distributions of 960 species of herbs and shrubs using 6,935 vegetation plots across the European Alps. We ran four models with different combinations of variables (climate, soil and tree cover) at both spatial grains for each species. We used partial regressions to evaluate the independent effects of plot- and landscape-grain tree cover on plot-level plant communities. Finally, the effects on species-specific elevational range limits were assessed by simulating a removal experiment comparing the species distributions under high and low tree cover. Accounting for tree cover improved the model performance, with the probability of the presence of shade-tolerant species increasing with increasing tree cover, whereas shade-intolerant species showed the opposite pattern. The tree cover effect occurred consistently at both the plot and landscape spatial grains, albeit most strongly at the former. Importantly, tree cover at the two grain sizes had partially independent effects on plot-level plant communities. With high tree cover, shade-intolerant species exhibited narrower elevational ranges than with low tree cover whereas shade-tolerant species showed wider elevational ranges at both limits. These findings suggest that forecasts of climate-related range shifts for herb

  14. Tree cover at fine and coarse spatial grains interacts with shade tolerance to shape plant species distributions across the Alps

    Science.gov (United States)

    Nieto-Lugilde, Diego; Lenoir, Jonathan; Abdulhak, Sylvain; Aeschimann, David; Dullinger, Stefan; Gégout, Jean-Claude; Guisan, Antoine; Pauli, Harald; Renaud, Julien; Theurillat, Jean-Paul; Thuiller, Wilfried; Van Es, Jérémie; Vittoz, Pascal; Willner, Wolfgang; Wohlgemuth, Thomas; Zimmermann, Niklaus E.; Svenning, Jens-Christian

    2015-01-01

    The role of competition for light among plants has long been recognised at local scales, but its importance for plant species distributions at larger spatial scales has generally been ignored. Tree cover modifies the local abiotic conditions below the canopy, notably by reducing light availability, and thus, also the performance of species that are not adapted to low-light conditions. However, this local effect may propagate to coarser spatial grains, by affecting colonisation probabilities and local extinction risks of herbs and shrubs. To assess the effect of tree cover at both the plot- and landscape-grain sizes (approximately 10-m and 1-km), we fit Generalised Linear Models (GLMs) for the plot-level distributions of 960 species of herbs and shrubs using 6,935 vegetation plots across the European Alps. We ran four models with different combinations of variables (climate, soil and tree cover) at both spatial grains for each species. We used partial regressions to evaluate the independent effects of plot- and landscape-grain tree cover on plot-level plant communities. Finally, the effects on species-specific elevational range limits were assessed by simulating a removal experiment comparing the species distributions under high and low tree cover. Accounting for tree cover improved the model performance, with the probability of the presence of shade-tolerant species increasing with increasing tree cover, whereas shade-intolerant species showed the opposite pattern. The tree cover effect occurred consistently at both the plot and landscape spatial grains, albeit most strongly at the former. Importantly, tree cover at the two grain sizes had partially independent effects on plot-level plant communities. With high tree cover, shade-intolerant species exhibited narrower elevational ranges than with low tree cover whereas shade-tolerant species showed wider elevational ranges at both limits. These findings suggest that forecasts of climate-related range shifts for herb

  15. Tree species richness as the element of structure and diversity in mixed stands of beech and valuable broadleaves

    Directory of Open Access Journals (Sweden)

    Stajić Branko

    2012-01-01

    Full Text Available In our forest science and forest operations, the tree species richness and diversity of woody species in forest stands are most often evaluated based on the total number of tree species, which is a methodologically partly inadequate approach. For this reason, the quantification and the evaluation of diversity of woody species in mixed forests of beech with valuable broadleaves in the area of the National Park „Đerdap” were analyzed by five different indices of tree species richness: number of species (S index, two indices of the species richness (R1 and R2, expected number of species in the sample with equal numbers of trees (E(S84, and expected number of species in the sample with equal areas (E(S0,25ha. The results showed that the level of woody species diversity in forest stands depended on the applied index characterizing the tree species richness. It was concluded that the tree species richness and diversity were the highest in the stands of ecological unit B (E(S84=8.6 species and in the stands of ecological unit G (E(S0,25ha=9.4 species, and they were the lowest in the stands of ecological unit V (E(S84=5.8 species, E(S0,25ha=5.5 species.

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

    Science.gov (United States)

    Jabot, Franck; Chave, Jérôme

    2011-08-01

    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.

  17. Fuel wood properties of some oak tree species of Manipur, India.

    Science.gov (United States)

    Meetei, Shougrakpam Bijen; Singh, E J; Das, Ashesh Kumar

    2015-07-01

    Five indigenous oak tree species, i.e., Castanopsis indica (Roxb. ex Lindl.) A.DC., Lithocarpus fenestratus (Roxb.) Rehder, Lithocarpus pachyphyllus (Kurz) Rehder, Lithocarpus polystachyus (Wall. ex A.DC.) Rehder and Quercus serrata Murray were estimated for their wood properties such as calorific value, density, moisture content and ash content from a sub-tropical forest of Haraothel hill, Senapati District, Manipur. Wood biomass components were found to have higher calorific value (kJ g(-)) than bark components. The calorific values for tree species were found highest in L. pachyphyllus (17.99 kJ g(-1)) followed by C. indica (17.98 kJ g1), L. fenestratus (17.96 kJ g"), L. polystachyus (17.80 kJ g(-1)) and Q. serrata (17.49 kJ g(-1)). Calorific values for bole bark, bole wood and branch bark were found significantly different (F > 3.48 at p = 0.05) in five oak tree species. Percentage of ash on dry weight basis was found to be highest in Q. serrata (4.73%) and lowest in C. indica (2.19%). Ash content of tree components gives a singnificant factor in determining fuelwood value index (FVI). Of all the five oak tree species, Q. serrata exhibited highest value of wood density (0.78 g cm-) and lowest was observed in C. indica (0.63 g cm(-3)). There was significant correlation between wood density (p L. pachyphyllus (898.41)> L. polystachyus (879.02)> L. fenestratus (824.61)> Q. serrata (792.50). Thus, the present study suggests that C. indica may be considered as a fuelwood oak tree species in Manipur.

  18. Assessment of suitability of tree species for the production of biomass on trace element contaminated soils.

    Science.gov (United States)

    Evangelou, Michael W H; Deram, Annabelle; Gogos, Alexander; Studer, Björn; Schulin, Rainer

    2012-03-30

    To alleviate the demand on fertile agricultural land for production of bioenergy, we investigated the possibility of producing biomass for bioenergy on trace element (TE) contaminated land. Soil samples and plant tissues (leaves, wood and bark) of adult willow (Salix sp.), poplar (Populus sp.), and birch (Betula pendula) trees were collected from five contaminated sites in France and Germany and analysed for Zn, Cd, Pb, Cu, Ca, and K. Cadmium concentration in tree leaves were correlated with tree species, whereas Zn concentration in leaves was site correlated. Birch revealed significantly lower leaf Cd concentrations (1.2-8.9 mg kg(-1)) than willow and poplar (5-80 mg kg(-1)), thus posing the lowest risk for TE contamination of surrounding areas. Birch displayed the lowest bark concentrations for Ca (2300-6200 mg kg(-1)) and K (320-1250 mg kg(-1)), indicating that it would be the most suitable tree species for fuel production, as high concentrations of K and Ca decrease the ash melting point which results in a reduced plant lifetime. Due to higher TE concentrations in bark compared to wood a small bark proportion in relation to the trunk is desirable. In general the bark proportion was reduced with the tree age. In summary, birch was amongst the investigated species the most suitable for biomass production on TE contaminated land. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Trees

    Science.gov (United States)

    Al-Khaja, Nawal

    2007-01-01

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

  20. Yeast Communities of Diverse Drosophila Species: Comparison of Two Symbiont Groups in the Same Hosts

    Science.gov (United States)

    Eisen, Jonathan A.; Kopp, Artyom

    2012-01-01

    The combination of ecological diversity with genetic and experimental tractability makes Drosophila a powerful model for the study of animal-associated microbial communities. Despite the known importance of yeasts in Drosophila physiology, behavior, and fitness, most recent work has focused on Drosophila-bacterial interactions. In order to get a more complete understanding of the Drosophila microbiome, we characterized the yeast communities associated with different Drosophila species collected around the world. We focused on the phylum Ascomycota because it constitutes the vast majority of the Drosophila-associated yeasts. Our sampling strategy allowed us to compare the distribution and structure of the yeast and bacterial communities in the same host populations. We show that yeast communities are dominated by a small number of abundant taxa, that the same yeast lineages are associated with different host species and populations, and that host diet has a greater effect than host species on yeast community composition. These patterns closely parallel those observed in Drosophila bacterial communities. However, we do not detect a significant correlation between the yeast and bacterial communities of the same host populations. Comparative analysis of different symbiont groups provides a more comprehensive picture of host-microbe interactions. Future work on the role of symbiont communities in animal physiology, ecological adaptation, and evolution would benefit from a similarly holistic approach. PMID:22885750

  1. Gas exchange and water balance of a mistletoe species and its mangrove hosts.

    Science.gov (United States)

    Goldstein, G; Rada, F; Sternberg, L; Burguera, J L; Burguera, M; Orozco, A; Montilla, M; Zabala, O; Azocar, A; Canales, M J; Celis, A

    1989-02-01

    The gas exchange and water relations of the hemiparasite Pthirusa maritima and two its mangrove host species, Conocarpus erectus and Coccoloba uvifera, were studied in an intertidal zone of the Venezuelan coast. Carbon uptake and transpiration, leaf osmotic and total water potential, as well as nutrient content in the xylem sap and leaves of mistletoes and hosts were followed through the dry and wet season. In addition, carbon isotope ratios of leaf tissue were measured to further evaluate water use efficiency. Under similar light and humidity conditions, mistletoes had higher transpiration rates, lower leaf water potentials, and lower water use efficiencies than their hosts. Potassium content was much higher in mistletoes than in host leaves, but mineral nutrient content in the xylem sap of mistletoes was relatively low. The resistance of the liquid pathway from the soil to the leaf surface of mistletoes was larger than the total liquid flow resistance of host plants. Differences in the daily cycles of osmotic potential of the xylem sap also indicate the existence of a high resistance pathway along the vascular connection between the parasite pathway along the vascular connection between the parasite and its host. P. maritima mistletoes adjust to the different physiological characteristics of the host species which it parasitizes, thus ensuring an adequate water and carbon balance.

  2. Alternative mechanisms of increased eggshell hardness of avian brood parasites relative to host species.

    Science.gov (United States)

    Igic, Branislav; Braganza, Kim; Hyland, Margaret M; Silyn-Roberts, Heather; Cassey, Phillip; Grim, Tomas; Rutila, Jarkko; Moskát, Csaba; Hauber, Mark E

    2011-11-07

    Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo Cuculus canorus, and their respective hosts. Using tools developed for materials science, we discovered a novel correlate of increased strength of parasite eggs: the common cuckoo's egg exhibits a greater microhardness, especially in the inner region of the shell matrix, relative to its host and sympatric non-host species. We then tested predictions of four potential mechanisms of shell strength: (i) increased relative thickness overall, (ii) greater proportion of the structurally harder shell layers, (iii) higher concentration of inorganic components in the shell matrix, and (iv) elevated deposition of a high density compound, MgCO(3), in the shell matrix. We confirmed support only for hypothesis (i). Eggshell characteristics did not differ between parasite eggs sampled from different host nests in distant geographical sites, suggesting an evolutionarily shared microstructural mechanism of stronger parasite eggshells across diverse host-races of brood parasitic cuckoos.

  3. Seasonal and meteorological effects on differential stemflow funneling ratios for two deciduous tree species

    Science.gov (United States)

    Siegert, C. M.; Levia, D. F.

    2014-11-01

    Stemflow is an important subcanopy flux that delivers enriched rainfall to soils immediately surrounding a tree. Stemflow volume represents the quantity of this hydrologic flux while funneling ratio (FR) represents the efficiency with which individual trees scavenge water during rainfall events. Stemflow hydrology and storm meteorological characteristics were monitored from 2007 through 2012 to determine the interspecific differences in stemflow flux with a focus on FR efficiency. The objective of this study was to examine the influence of tree species and size on stemflow FR, determine how seasonality affects stemflow FR, and quantify the role of storm meteorological conditions on stemflow FR. The results presented in this paper build upon 2 years of previous hydrologic research from the Fair Hill, MD field site, which strengthen previous findings via larger storm sample size and highlight more complex stemflow hydrologic relationships than originally assumed. Specifically, this study has demonstrated (1) the efficiency with which smaller trees gain access to rainfall via higher FR than larger trees, (2) the FR variability of F. grandifolia induced by the species' ease of generating stemflow under many storm conditions, and (3) the necessity of many years of hydrometeorological sampling to capture long-term rainfall characteristics and trends. The efficiency of smaller trees to preferentially funnel water to their tree base has implications for forests undergoing change. Forest disturbance and subsequent regrowth is dominated by smaller trees, but additional research is necessary to understand how saplings compete among one another to gain access to stemflow and how this may be influenced by changing climates and forest composition.

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

    Science.gov (United States)

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

    2013-03-01

    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.

  5. Prevalence and beta diversity in avian malaria communities: host species is a better predictor than geography.

    Science.gov (United States)

    Scordato, Elizabeth S C; Kardish, Melissa R

    2014-11-01

    Patterns of diversity and turnover in macroorganism communities can often be predicted from differences in habitat, phylogenetic relationships among species and the geographical scale of comparisons. In this study, we asked whether these factors also predict diversity and turnover in parasite communities. We studied communities of avian malaria in two sympatric, ecologically similar, congeneric host species at three different sites. We asked whether parasite prevalence and community structure varied with host population, host phylogeography or geographical distance. We used PCR to screen birds for infections and then used Bayesian methods to determine phylogenetic relationships among malaria strains. Metrics of both community and phylogenetic beta diversity were used to examine patterns of malaria strain turnover between host populations, and partial Mantel tests were used determine the correlation between malaria beta diversity and geographical distance. Finally, we developed microsatellite markers to describe the genetic structure of host populations and assess the relationship between host phylogeography and parasite beta diversity. We found that different genera of malaria parasites infect the two hosts at different rates. Within hosts, parasite communities in one population were phylogenetically clustered, but there was otherwise no correlation between metrics of parasite beta diversity and geographical or genetic distance between host populations. Patterns of parasite turnover among host populations are consistent with malaria transmission occurring in the winter rather than on the breeding grounds. Our results indicate greater turnover in parasite communities between different hosts than between different study sites. Differences in host species, as well as transmission location and vector ecology, seem to be more important in structuring malaria communities than the distance-decay relationships frequently found in macroorganisms. Determining the factors

  6. Attraction of two lacewing species to volatiles produced by host plants and aphid prey

    Science.gov (United States)

    Zhu, J.; Obrycki, J. J.; Ochieng, Samuel A.; Baker, Thomas C.; Pickett, J. A.; Smiley, D.

    2005-06-01

    It is well documented that host-related odors enable many species of parasitoids and predatory insects to locate their prey and prey habitats. This study reports the first characterization of prey and prey host odor reception in two species of lacewings, Chrysoperla carnea (Say) and Chrysopa oculata L. 2-Phenylethanol, one of the volatiles emitted from their prey’s host plants (alfalfa and corn) evoked a significant EAG response from antennae of C. carnea. Traps baited with this compound attracted high numbers of adult C. carnea, which were predominantly females. One of the sex pheromone components (1R,4aS,7S,7aR)-nepetalactol of an aphid species, Acyrthosiphon pisum (Harris) attracted only C. oculata adults. Single sensillum recordings showed that the olfactory neurons of C. carnea responded to both 2-phenylethanol and aphid sex pheromone components, but those of C. oculata only responded to the latter.

  7. Direct vs. Microclimate-Driven Effects of Tree Species Diversity on Litter Decomposition in Young Subtropical Forest Stands.

    Directory of Open Access Journals (Sweden)

    Katrin N Seidelmann

    Full Text Available Effects of tree species diversity on decomposition can operate via a multitude of mechanism, including alterations of microclimate by the forest canopy. Studying such effects in natural settings is complicated by the fact that topography also affects microclimate and thus decomposition, so that effects of diversity are more difficult to isolate. Here, we quantified decomposition rates of standard litter in young subtropical forest stands, separating effects of canopy tree species richness and topography, and quantifying their direct and micro-climate-mediated components. Our litterbag study was carried out at two experimental sites of a biodiversity-ecosystem functioning field experiment in south-east China (BEF-China. The field sites display strong topographical heterogeneity and were planted with tree communities ranging from monocultures to mixtures of 24 native subtropical tree species. Litter bags filled with senescent leaves of three native tree species were placed from Nov. 2011 to Oct. 2012 on 134 plots along the tree species diversity gradient. Topographic features were measured for all and microclimate in a subset of plots. Stand species richness, topography and microclimate explained important fractions of the variations in litter decomposition rates, with diversity and topographic effects in part mediated by microclimatic changes. Tree stands were 2-3 years old, but nevertheless tree species diversity explained more variation (54.3% in decomposition than topography (7.7%. Tree species richness slowed litter decomposition, an effect that slightly depended on litter species identity. A large part of the variance in decomposition was explained by tree species composition, with the presence of three tree species playing a significant role. Microclimate explained 31.4% of the variance in decomposition, and was related to lower soil moisture. Within this microclimate effect, species diversity (without composition explained 8.9% and

  8. Response of brown-headed cowbirds and three host species to thinning treatments in low-elevation ponderosa pine forests along the northern Colorado Front Range

    Science.gov (United States)

    Keeley, W.H.; Germaine, Stephen S.; Stanley, Thomas R.; Spaulding, Sarah A.; Wanner, C.E.

    2013-01-01

    Thinning ponderosa pine (Pinus ponderosa) forests to achieve desired ecological conditions remains a priority in the North American west. In addition to reducing the risk of high-severity wildfires in unwanted areas, stand thinning may increase wildlife and plant diversity and provide increased opportunity for seedling recruitment. We initiated conservative (i.e. minimal removal of trees) ponderosa stand thinning treatments with the goals of reducing fire risk and improving habitat conditions for native wildlife and flora. We then compared site occupancy of brown-headed cowbirds (Molothrus ater), chipping sparrows (Spizella passerina), plumbeous vireos (Vireo plumbeus), and western wood-pewees (Contopus sordidulus) in thinned and unthinned (i.e., control) forest stands from 2007 to 2009. Survey stations located in thinned stands had 64% fewer trees/ha, 25% less canopy cover, and 23% less basal area than stations in control stands. Occupancy by all three host species was negatively associated with tree density, suggesting that these species respond favorably to forest thinning treatments in ponderosa pine forests. We also encountered plumbeous vireos more frequently in plots closer to an ecotonal (forest/grassland) edge, an association that may increase their susceptibility to edge-specialist, brood parasites like brown-headed cowbirds. Occupancy of brown-headed cowbirds was not related to forest metrics but was related to occupancy by plumbeous vireos and the other host species in aggregate, supporting previous reports on the affiliation between these species. Forest management practices that promote heterogeneity in forest stand structure may benefit songbird populations in our area, but these treatments may also confer costs associated with increased cowbird occupancy. Further research is required to understand more on the complex relationships between occupancy of cowbirds and host species, and between cowbird occupancy and realized rates of nest parasitism.

  9. The host-defence skin peptide profiles of Peron's Tree Frog Litoria peronii in winter and summer. Sequence determination by electrospray mass spectrometry and activities of the peptides.

    Science.gov (United States)

    Bilusich, Daniel; Jackway, Rebecca J; Musgrave, Ian F; Tyler, Michael J; Bowie, John H

    2009-09-01

    Positive and negative ion electrospray mass spectrometry together with Edman sequencing (when appropriate) has been used to sequence the host-defence peptides secreted from skin glands of the tree frog Litoria peronii. The peptide profiles are different in winter and summer. In winter, the frog produces small amounts of the known caerin 1.1 [GLLSVLGSVAKHVLPHVVPVIAEHL-NH(2)] (a wide-spectrum antibiotic) and caerin 2.1 [GLVSSIGRALGGLLADVVKSKQPA-OH], a narrow-spectrum antibiotic and an inhibitor of neuronal nitric oxide synthase. The major peptides produced throughout the year are the pGlu-containing peroniins 1.1 to 1.5 (e.g. peroniin 1.1 [pEPWLPFG-NH(2)], a smooth muscle contractor from 10(-7) M), and caerulein [pEQDY(SO(3)H)TGWMDF-NH(2)], a known and potent smooth muscle contractor from 10(-10) M. There are also some precursors to the peroniin 1 peptides, only detected in the skin secretion in summer, which are inactive and appear to be all (or part) of the spacer peroniin 1 peptides, e.g. peroniin 1.1b [SEEEKRQPWLPFG-NH(2)]. There are three members of the Litoria peronii Group of tree frogs classified in Australia, namely, L. peronii, L. rothii and L.tyleri. A comparison of the skin peptide profiles of L. peronii with those reported previously for L. rothii suggests that either these two species of tree frog are not as closely related as determined previously on morphological grounds, or that skin peptide divergence in tree frogs of this Group is more extensive than in others that have been studied. Copyright (c) 2009 John Wiley & Sons, Ltd.

  10. Patterns of tree species diversity in relation to climatic factors on the Sierra Madre Occidental, Mexico.

    Science.gov (United States)

    Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian

    2014-01-01

    Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within species, between species, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different species of Pinus (ca. 22% on the whole), 54 species of Quercus (ca. 9-14%), 7 species of Arbutus (ca. 50%) and many other trees species. The objectives of this study were to model how tree species diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum tree species diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of tree species are generally higher in cold

  11. Patterns of tree species diversity in relation to climatic factors on the Sierra Madre Occidental, Mexico.

    Directory of Open Access Journals (Sweden)

    Ramón Silva-Flores

    Full Text Available Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within species, between species, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different species of Pinus (ca. 22% on the whole, 54 species of Quercus (ca. 9-14%, 7 species of Arbutus (ca. 50% and many other trees species. The objectives of this study were to model how tree species diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum tree species diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of tree species are generally

  12. Divergence in strategies for coping with winter embolism among co-occurring temperate tree species: the role of positive xylem pressure, wood type and tree stature

    Science.gov (United States)

    Cun-Yang Niu; Frederick C. Meinzer; Guang-You. Hao

    2017-01-01

    1. In temperate ecosystems, freeze-thaw events are an important environmental stress that can induce severe xylem embolism (i.e. clogging of conduits by air bubbles) in overwintering organs of trees. However, no comparative studies of different adaptive strategies among sympatric tree species for coping with winter embolism have examined the potential role of the...

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

    Science.gov (United States)

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

    2009-12-01

    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.

  14. Assessment of suitability of tree species for the production of biomass on trace element contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Evangelou, Michael W.H., E-mail: michael.evangelou@env.ethz.ch [Institute of Terrestrial Ecosystems, ETH Zuerich, Universitaetstrasse 16, CH-8092 Zuerich (Switzerland); Deram, Annabelle, E-mail: annabelle.deram@univ-lille2.fr [Laboratoire des sciences vegetales et fongiques - EA4483, Faculte des sciences pharmaceutiques et biologiques-ILIS, Universite Lille Nord de France - 3, rue du Professeur Laguesse, B.P. 83, F-59006 Lille Cedex (France); Gogos, Alexander; Studer, Bjoern; Schulin, Rainer [Institute of Terrestrial Ecosystems, ETH Zuerich, Universitaetstrasse 16, CH-8092 Zuerich (Switzerland)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Birch: lowest metal concentrations in foliage, wood and bark. Black-Right-Pointing-Pointer Bark proportion does not have to decline with increasing age of tree. Black-Right-Pointing-Pointer Long harvest rotation (>25 y) reduces metal concentrations in stem. Black-Right-Pointing-Pointer Birch: most suitable tree for BCL. - Abstract: To alleviate the demand on fertile agricultural land for production of bioenergy, we investigated the possibility of producing biomass for bioenergy on trace element (TE) contaminated land. Soil samples and plant tissues (leaves, wood and bark) of adult willow (Salix sp.), poplar (Populus sp.), and birch (Betula pendula) trees were collected from five contaminated sites in France and Germany and analysed for Zn, Cd, Pb, Cu, Ca, and K. Cadmium concentration in tree leaves were correlated with tree species, whereas Zn concentration in leaves was site correlated. Birch revealed significantly lower leaf Cd concentrations (1.2-8.9 mg kg{sup -1}) than willow and poplar (5-80 mg kg{sup -1}), thus posing the lowest risk for TE contamination of surrounding areas. Birch displayed the lowest bark concentrations for Ca (2300-6200 mg kg{sup -1}) and K (320-1250 mg kg{sup -1}), indicating that it would be the most suitable tree species for fuel production, as high concentrations of K and Ca decrease the ash melting point which results in a reduced plant lifetime. Due to higher TE concentrations in bark compared to wood a small bark proportion in relation to the trunk is desirable. In general the bark proportion was reduced with the tree age. In summary, birch was amongst the investigated species the most suitable for biomass production on TE contaminated land.

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

    Science.gov (United States)

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

    2008-01-01

    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.

  16. Demographic variation and habitat specialization of tree species in a diverse tropical forest of Cameroon

    Directory of Open Access Journals (Sweden)

    David Kenfack

    2014-11-01

    Full Text Available Background Many tree species in tropical forests have distributions tracking local ridge-slope-valley topography. Previous work in a 50-ha plot in Korup National Park, Cameroon, demonstrated that 272 species, or 63% of those tested, were significantly associated with topography. Methods We used two censuses of 329,000 trees ≥1 cm dbh to examine demographic variation at this site that would account for those observed habitat preferences. We tested two predictions. First, within a given topographic habitat, species specializing on that habitat (‘residents’ should outperform species that are specialists of other habitats (‘foreigners’. Second, across different topographic habitats, species should perform best in the habitat on which they specialize (‘home’ compared to other habitats (‘away’. Species’ performance was estimated using growth and mortality rates. Results In hierarchical models with species identity as a random effect, we found no evidence of a demographic advantage to resident species. Indeed, growth rates were most often higher for foreign species. Similarly, comparisons of species on their home vs. away habitats revealed no sign of a performance advantage on the home habitat. Conclusions We reject the hypothesis that species distributions along a ridge-valley catena at Korup are caused by species differences in trees ≥1 cm dbh. Since there must be a demographic cause for habitat specialization, we offer three alternatives. First, the demographic advantage specialists have at home occurs at the reproductive or seedling stage, in sizes smaller than we census in the forest plot. Second, species may have higher performance on their preferred habitat when density is low, but when population builds up, there are negative density-dependent feedbacks that reduce performance. Third, demographic filtering may be produced by extreme environmental conditions that we did not observe during the census interval.

  17. Photosynthetic capacity of senescent leaves for a subtropical broadleaf deciduous tree species Liquidambar formosana Hance.

    Science.gov (United States)

    Luo, Zidong; Guan, Huade; Zhang, Xinping; Liu, Na

    2017-07-24

    Photosynthetic capacity and leaf life span generally determine how much carbon a plant assimilates during the growing season. Leaves of deciduous tree species start senescence in late season, but whether the senescent leaves still retain capacity of carbon assimilation remains a question. In this study, we investigated leaf phenology and photosynthesis of a subtropical broadleaf deciduous tree species Liquidambar formosana Hance in the central southern continental China. The results show that L. formosana has extended leaf senescence (more than 2 months) with a substantial number of red leaves persisting on the tree. Leaf photosynthetic capacity decreases over season, but the senescent red leaves still maintain relatively high photosynthetic capacity at 42%, 66% and 66% of the mature leaves for net photosynthesis rate, apparent quantum yield, and quantum yield at the light compensation point, respectively. These results indicate that L. formosana may still contribute to carbon sink during leaf senescence.

  18. Future of the Main Important Forest Tree Species in Serbia from the Climate Change Perspective

    Directory of Open Access Journals (Sweden)

    Dejan B. Stojanović

    2014-12-01

    Full Text Available Background and Purpose: Climate change is possibly the biggest 21st century challenge for the European forestry. Serbia is also under pressure, since the regions of South Europe and Mediterranean are expected to suffer the most. Main purpose of this study was to predict how distribution of several tree species in Serbia may change in the future. Materials and Methods: Our study integrates climate change scenarios for the region of Serbia together with the current distribution of forest tree species. Evaluation was performed using forest aridity index which takes into account mean temperatures and sums of precipitation of the critical months during the growing season. Distribution data of the nine most abundant tree species in Serbia (European beech, Turkey oak, Sessile oak, Hungarian oak, Pedunculate oak, Norway spruce, Silver fir, Black and Scots pine were taken from the National Forest Inventory. Results: Significant change of bioclimatic niches is expected for the majority of the studied tree species. The most endangered will be Pedunculate oak due to the extreme change of its habitats, while drought prone species (like pines and Hungarian oak will be less endangered. Sessile oak, Turkey oak, Silver fir, Norway spruce and European beech will be out of their 20th century bioclimatic niches before the end of 21st century according to A2 scenario. Conclusion: Our results suggest that some of the most important tree species in Serbia (Sessile oak, Turkey oak, Silver fir, Norway spruce and European beech will be endangered by the end of 21st century. General adaption options and specific measurements for forestry sector have to be made for the region of southeast Europe due to the expected extreme change in climate.

  19. Stress responses in Streptococcus species and their effects on the host.

    Science.gov (United States)

    Nguyen, Cuong Thach; Park, Sang-Sang; Rhee, Dong-Kwon

    2015-11-01

    Streptococci cause a variety of diseases, such as dental caries, pharyngitis, meningitis, pneumonia, bacteremia, endocarditis, erysipelas, and necrotizing fasciitis. The natural niche of this genus of bacteria ranges from the mouth and nasopharynx to the skin, indicating that the bacteria will inevitably be subjected to environmental changes during invasion into the host, where it is exposed to the host immune system. Thus, the Streptococcus-host interaction determines whether bacteria are cleared by the host's defenses or whether they survive after invasion to cause serious diseases. If this interaction was to be deciphered, it could aid in the development of novel preventive and therapeutic agents. Streptococcus species possess many virulent factors, such as peroxidases and heat-shock proteins (HSPs), which play key roles in protecting the bacteria from hostile host environments. This review will discuss insights into the mechanism(s) by which streptococci adapt to host environments. Additionally, we will address how streptococcal infections trigger host stress responses; however, the mechanism by which bacterial components modulate host stress responses remains largely unknown.

  20. Variations in Host Preference among and within Populations of Heterodera trifolii and Related Species.

    Science.gov (United States)

    Wang, S; Riggs, R D

    1999-12-01

    Seven populations of Heterodera trifolii from Arkansas, Kentucky, Pennsylvania, and Australia plus 3 or 4 single-cyst isolates (SCI) from each population were tested for reproduction on seven species of plants to compare the host preferences among and within populations. Common lespedeza, Kummerowia striata cv. Kobe, was a good host for all populations and isolates. Therefore, a plant was considered to be a host if the number of females produced on it was 10% or more of the number on Kobe. All seven populations reproduced on Trifolium repens and T. pratense. None reproduced on Beta vulgaris or Glycine max. One single-cyst isolate from the Australian population produced a few females on T. pratense. The Australian population maintained on carnation, Dianthus caryophyllus, produced females on carnation but not on curly dock, Rumex crispus. However, its subpopulation maintained on T. repens produced females on R. crispus but not on carnation. Four of the other six populations produced females on R. crispus, and four produced females on carnation. Differences in host range were observed among seven of the mother populations and their SCI, and among isolates within each population. Five host range patterns were found in populations and SCI of H. trifolii. Significant quantitative differences occurred among populations in the numbers of females on most hosts, between isolates and their original populations, and among isolates from the same population. SCI selected from white clover produced fewer females on a series of test hosts and had host ranges the same as or narrower than those of the original populations. However, SCI selected from Kobe lespedeza had more females on some hosts and had host ranges the same as or wider than those of the original populations. The host ranges of all populations and SCI of H. trifolii were different from those of populations and SCI of race 3 of H. glycines and H. lespedezae.

  1. Dominance and diversity studies of tree species in lesser Himalayan forest of Uttarakhand, India

    Directory of Open Access Journals (Sweden)

    A.S. BISHT

    2016-04-01

    Full Text Available Abstract. Bisht AS, Bhatt AB. 2016. Dominance and diversity studies of tree species in lesser Himalayan forest of Uttarakhand, India. Biodiversitas 17: 70-77. For the present investigation single mountain, approach was applied. This is a supplement the basic approach and extends the gradients further downward in to the forest belt. Vegetational analysis of nine stands covering all the four aspects of the study site of Pauri Garhwal district of Uttarakhand, India has been undertaken. In seven trees, species were encountered. East aspect is characteristics by highest density of Cupressus torulosa while west aspect comprised of Cedrus deodara, Myrica esculenta, Pinus. roxbugrhii, Quercus. leucotrichophora and Rhododendron arboreum, i.e. high diversity with low dominance Cupressus torulosa and Cedrus deodara dominated the north aspect. In general, influence of higher anthropogenic pressure on Quercus species is an important factor for leads to gradual replacement of oak species by Pinus roxburghii in all the aspects.

  2. Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species

    Directory of Open Access Journals (Sweden)

    W. John Calder

    2010-01-01

    Full Text Available Smoke from forest fires can persist in the environment for weeks and while there is a substantial amount of literature examining the effects of smoke exposure on seed germination, the effects of smoke on leaf function are nearly uninvestigated. The objective of this study was to compare growth and primary and secondary metabolic responses of deciduous angiosperm and evergreen conifer tree species to short smoke exposure. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.

  3. Food-web-based comparison of the drivers of helminth parasite species richness in coastal fish and bird definitive hosts

    NARCIS (Netherlands)

    Thieltges, D.W.; Poulin, R.

    2016-01-01

    Studies on the factors determining parasite richness in hosts are typically performedusing data compiled for various sets of species from disparate habitats. However, parasite transmissionis embedded within local trophic networks, and proper comparisons among host speciesof the drivers of parasite

  4. Effects of groundwater abstraction on two keystone tree species in an arid savanna national park.

    Science.gov (United States)

    Shadwell, Eleanor; February, Edmund

    2017-01-01

    In arid systems with no surface water, deep boreholes in ephemeral river beds provide for humans and animals. With continually increasing infrastructure development for tourism in arid wildlife parks such as the Kgalagadi Transfrontier Park in southern Africa, we ask what effects increased abstraction may have on large trees. Large trees in arid savannas perform essential ecosystem services by providing food, shade, nesting sites and increased nutrients for many other plant and animal species and for this are regarded as keystone species. We determine seasonal fluctuations in the water table while also determining the water source for the dominant large tree species in the Auob and Nossob rivers in the Park. We also determine the extent to which these trees are physiologically stressed using leaf δ(13)C, xylem pressure potentials, specific leaf area and an estimate of canopy death. We do this both upstream and downstream of a low water use borehole in the Auob River and a high water use borehole in the Nossob River. Our results show that the trees are indeed using deep groundwater in the wet season and that this is the same water used by people. In the dry season, trees in the Auob downstream of the active borehole become detached from the aquifer and use more isotopically enriched soil water. In the Nossob in the dry season, all trees use isotopically enriched soil water, and downstream of the active borehole use stomatal regulation to maintain leaf water potentials. These results suggest that trees in the more heavily utilised Nossob are under more water stress than those trees in the Auob but that trees in both rivers demonstrate physiological adaptation to the changes in available water with smaller heavier leaves, no significant canopy dieback and in the dry season in the Nossob stomatal regulation of leaf water potentials. An increase in abstraction of groundwater particularly at the Nossob borehole may cause an additional draw down of the water table adding

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

    Science.gov (United States)

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

    1999-01-01

    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 (olden as model...

  6. Disturbance Level Determines the Regeneration of Commercial Tree Species in the Eastern Amazon

    NARCIS (Netherlands)

    Schwartz, G.; Lopes, J.C.; Kanashiro, M.; Mohren, G.M.J.; Pena Claros, M.

    2014-01-01

    The effects of reduced-impact logging (RIL) on the regeneration of commercial tree species were investigated, as long-term timber yields depend partly on the availability of seedlings in a managed forest. On four occasions during a 20-month period in the Tapajós National Forest (Eastern Amazon,

  7. Hierarchical spatial models for predicting tree species assemblages across large domains

    Science.gov (United States)

    Andrew O. Finley; Sudipto Banerjee; Ronald E. McRoberts

    2009-01-01

    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...

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

    Science.gov (United States)

    K. K. Christensen-Dalsgaard; M. T. Tyree; P. G. Mussone

    2011-01-01

    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...

  9. Invasion by native tree species prevents biotic homogenization in novel forests of Puerto Rico

    Science.gov (United States)

    Oscar J. Abelleira Martinez

    2010-01-01

    There is concern that secondary forests dominated by introduced species, known as novel forests, increase taxonomical similarity between localities and lead to biotic homogenization in human dominated landscapes. In Puerto Rico, agricultural abandonment has given way to novel forests dominated by the introduced African tulip tree Spathodea campanulata Beauv. (...

  10. Changes in the relationship between annual tree growth and climatic variables for four hardwood species

    Science.gov (United States)

    E.R. Smith; J.C. Rennie

    1991-01-01

    A study was conducted to characterize temporal and spatial variability in the growth response of four major hardwood species (white oak, chestnut oak, northern red oak, and yellow-poplar) to climatic fluctuations, and to evaluate the role of environmental factors associated with difference in response among individuals. The study incorporated tree-ring data collected...

  11. Combining binary classifiers to improve tree species discrimination at leaf level

    CSIR Research Space (South Africa)

    Dastile, X

    2012-11-01

    Full Text Available variability which makes discrimination between the tree species (hereafter referred to as classes) challenging. We focus on two classification methods: K-nearest neighbour and feed-forward neural networks for the discrimination of the classes. For both methods...

  12. Seed germination methods for native Caribbean trees and shrubs : with emphasis on species relevant for Bonaire

    NARCIS (Netherlands)

    Burg, van der W.J.; Freitas, J.; Debrot, A.O.

    2014-01-01

    This paper is intended as a basis for nature restoration activities using seeds of trees and (larger) shrubs native to Bonaire with the aim of reforestation. It describes the main seed biology issues relevant for species from this region, to facilitate decisions on time and stage of harvesting, safe

  13. Tree-species range shifts in a changing climate: detecting, modeling, assisting

    Science.gov (United States)

    Louis R. Iverson; Donald. McKenzie

    2013-01-01

    In these times of rapidly changing climate, the science of detecting and modeling shifts in the ranges of tree species is advancing of necessity. We briefly review the current state of the science on several fronts. First, we review current and historical evidence for shifting ranges and migration. Next, we review two broad categories of methods, focused on the spatial...

  14. Status of non-cocoa tree species in cocoa multistrata systems of ...

    African Journals Online (AJOL)

    Investigations to assess the status of non-cocoa tree species in the cocoa systems of southern Cameroon were carried out in four contrasting locations, distinguished by ecology, population density and land use intensity. One set of inventory was done in each of the 20 selected cocoa farms with an average surface area of ...

  15. Estimating the global conservation status of more than 15,000 Amazonian tree species

    DEFF Research Database (Denmark)

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree ...

  16. Spatial patterns of soil pathogens in declining Mediterranean forests: implications for tree species regeneration.

    Science.gov (United States)

    Gómez-Aparicio, Lorena; Ibáñez, Beatriz; Serrano, María S; De Vita, Paolo; Avila, José M; Pérez-Ramos, Ignacio M; García, Luis V; Esperanza Sánchez, M; Marañón, Teodoro

    2012-06-01

    Soil-borne pathogens are a key component of the belowground community because of the significance of their ecological and socio-economic impacts. However, very little is known about the complexity of their distribution patterns in natural systems. Here, we explored the patterns, causes and ecological consequences of spatial variability in pathogen abundance in Mediterranean forests affected by oak decline. We used spatially explicit neighborhood models to predict the abundance of soil-borne pathogen species (Phytophthora cinnamomi, Pythium spiculum and Pythium spp.) as a function of local abiotic conditions (soil texture) and the characteristics of the tree and shrub neighborhoods (species composition, size and health status). The implications of pathogen abundance for tree seedling performance were explored by conducting a sowing experiment in the same locations in which pathogen abundance was quantified. Pathogen abundance in the forest soil was not randomly distributed, but exhibited spatially predictable patterns influenced by both abiotic and, particularly, biotic factors (tree and shrub species). Pathogen abundance reduced seedling emergence and survival, but not in all sites or tree species. Our findings suggest that heterogeneous spatial patterns of pathogen abundance at fine spatial scale can be important for the dynamics and restoration of declining Mediterranean forests. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  17. Effects of sample survey design on the accuracy of classification tree models in species distribution models

    Science.gov (United States)

    Thomas C. Edwards; D. Richard Cutler; Niklaus E. Zimmermann; Linda Geiser; Gretchen G. Moisen

    2006-01-01

    We evaluated the effects of probabilistic (hereafter DESIGN) and non-probabilistic (PURPOSIVE) sample surveys on resultant classification tree models for predicting the presence of four lichen species in the Pacific Northwest, USA. Models derived from both survey forms were assessed using an independent data set (EVALUATION). Measures of accuracy as gauged by...

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  19. Responses of tree species to heat waves and extreme heat events.

    Science.gov (United States)

    Teskey, Robert; Wertin, Timothy; Bauweraerts, Ingvar; Ameye, Maarten; McGuire, Mary Anne; Steppe, Kathy

    2015-09-01

    The number and intensity of heat waves has increased, and this trend is likely to continue throughout the 21st century. Often, heat waves are accompanied by drought conditions. It is projected that the global land area experiencing heat waves will double by 2020, and quadruple by 2040. Extreme heat events can impact a wide variety of tree functions. At the leaf level, photosynthesis is reduced, photooxidative stress increases, leaves abscise and the growth rate of remaining leaves decreases. In some species, stomatal conductance increases at high temperatures, which may be a mechanism for leaf cooling. At the whole plant level, heat stress can decrease growth and shift biomass allocation. When drought stress accompanies heat waves, the negative effects of heat stress are exacerbated and can lead to tree mortality. However, some species exhibit remarkable tolerance to thermal stress. Responses include changes that minimize stress on photosynthesis and reductions in dark respiration. Although there have been few studies to date, there is evidence of within-species genetic variation in thermal tolerance, which could be important to exploit in production forestry systems. Understanding the mechanisms of differing tree responses to extreme temperature events may be critically important for understanding how tree species will be affected by climate change. © 2014 John Wiley & Sons Ltd.

  20. Species tree of a recent radiation: the subfamily Delphininae (Cetacea, Mammalia).

    Science.gov (United States)

    Amaral, Ana R; Jackson, Jennifer A; Möller, Luciana M; Beheregaray, Luciano B; Manuela Coelho, M

    2012-07-01

    Lineages undergoing rapid radiations provide exceptional opportunities for studying speciation and adaptation, but also represent a challenge for molecular systematics because retention of ancestral polymorphisms and the occurrence of hybridization can obscure relationships among lineages. Dolphins in the subfamily Delphininae are one such case. Non-monophyly, rapid speciation events, and discordance between morphological and molecular characters have made the inference of phylogenetic relationships within this subfamily very difficult. Here we approach this problem by applying multiple methods intended to estimate species trees using a multi-gene dataset for the Delphininae (Sousa, Sotalia, Stenella, Tursiops, Delphinus and Lagenodelphis). Incongruent gene trees obtained indicate that incomplete lineage sorting and possibly hybridization are confounding the inference of species history in this group. Nonetheless, using coalescent-based methods, we have been able to extract an underlying species-tree signal from divergent histories of independent genes. This is the first time a molecular study provides support for such relationships. This study further illustrates how methods of species-tree inference can be very sensitive both to the characteristics of the dataset and the evolutionary processes affecting the evolution of the group under study. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. [Compatible biomass models for main tree species with measurement error in Heilongjiang Province of Northeast China].

    Science.gov (United States)

    Dong, Li-hu; Li, Feng-ri; Jia, Wei-wei; Liu, Fu-xiang; Wang, He-zhi

    2011-10-01

    Based on the biomass data of 516 sampling trees, and by using non-linear error-in-variable modeling approach, the compatible models for the total biomass and the biomass of six components including aboveground part, underground part, stem, crown, branch, and foliage of 15 major tree species (or groups) in Heilongjiang Province were established, and the best models for the total biomass and components biomass were selected. The compatible models based on total biomass were developed by adopting the method of joint control different level ratio function. The heteroscedasticity of the models for total biomass was eliminated with log transformation, and the weighted regression was applied to the models for each individual component. Among the compatible biomass models established for the 15 major species (or groups) , the model for total biomass had the highest prediction precision (90% or more), followed by the models for aboveground part and stem biomass, with a precision of 87.5% or more. The prediction precision of the biomass models for other components was relatively low, but it was still greater than 80% for most test tree species. The modeling efficiency (EF) values of the total, aboveground part, and stem biomass models for all the tree species (or groups) were over 0.9, and the EF values of the underground part, crown, branch, and foliage biomass models were over 0.8.

  2. Nursery growth and biomass of the seedlings of nine tree species ...

    African Journals Online (AJOL)

    Four types of potting media, three of them mixed from different proportions (farm yard manure, forest soil, sand), and the local soil were compared. A factorial experiment was laid out in Randomized Complete Block Design. ANOVA on growth and biomass data were performed for nine tree species using the GLM procedure ...

  3. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, Barend S. van; Olff, Han; Parren, Marc P.E.; Bongers, Frans

    2003-01-01

    Aim: Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  4. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, van B.S.; Olff, H.; Parren, M.P.E.; Bongers, F.J.J.M.

    2003-01-01

    Aim Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  5. Do seasonal profiles of foliar pigments improve species discrimination of evergreen coastal tree species in KwaZulu- Natal, South Africa?

    CSIR Research Space (South Africa)

    Van Deventer, Heidi

    2013-04-01

    Full Text Available pigments, as well as improve species discrimination. This study investigated the potential of seasonal pigment profiles (for foliar carotenoid and total chlorophyll) in improving species discrimination for trees using leaf spectral data. Our aims were to (i...

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

    Science.gov (United States)

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

    2013-01-01

    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.

  7. Estimating the global conservation status of more than 15,000 Amazonian tree species

    OpenAIRE

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salom?o, Rafael P.; Castilho, Carolina V.; Amaral, I?da Le?o; de Almeida Matos, Francisca Dion?zia; de Souza Coelho, Luiz; Magnusson, William E.; Phillips, Oliver L.; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened ...

  8. Tree species diversity and regeneration of tropical dry forests in Nicaragua

    OpenAIRE

    González-Rivas, Benigno

    2005-01-01

    The thesis summarises results from four studies in dry forests of Nicaragua aiming to gain knowledge supporting conservation and rehabilitation efforts in these highly threatened forests. In the first study, tree species composition, structure and diversity of dry deciduous and gallery forests was carried out in Chacocente National Wildlife Refuge during 1994 and 2000. A total of 29 families, 49 genera and 59 species were represented in 2 ha permanent plots in dry deciduous forest during 1994...

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

    Science.gov (United States)

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

    2017-12-01

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

  10. HOST PLANTS AND CLIMATIC PREFERENCES OF THE INVASIVE SPECIES METCALFA PRUINOSA (SAY 1830 (HEMIPTERA: FLATIDAE IN SOME PLACES FROM SOUTHERN ROMANIA

    Directory of Open Access Journals (Sweden)

    Daniela Barbuceanu

    2015-12-01

    Full Text Available Observations carried out in May-September 2015 in two sites of Southern Romania reveal a rich spectrum of host plants for Metcalfa pruinosa, which consists of 204 species in 56 families. The species it is noticed on weeds and cultivated plants. The remarkable polyphagia of this species, the lack of natural enemies, and the climatic conditions of 2015 - warm and dry summer, had lead to an invasion of M. pruinosa, in the researched areas; the highest numerical abundances are noticed in shady habitats. Furthermore, on herbs, such as Levisticum officinale, Artemisia dracunculus, Ocimum basilicum, Mentha spp., usually avoided by pests, were observed colonies of the species. It is recorded high numerical abundance on fruit trees and shrubs: Hippophaë rhamnoides, Juglans regia, Prunus cerasus, Vitis vinifera, Rubus idaeus. The harmful effect occurs on apple trees Romus 1 variety as a result of the association with another pest of American origin, Eriosoma lanigerum, situation that favors the attack of the Erwinia amylovora bacteria, causing the collapse of the tree. It is found that altitudes higher than 200 m do not represent a limitative factor in the spreading of species, one of the investigated sites being located at 304 m altitude.

  11. Narrowing historical uncertainty: probabilistic classification of ambiguously identified tree species in historical forest survey data

    Science.gov (United States)

    Mladenoff, D.J.; Dahir, S.E.; Nordheim, E.V.; Schulte, L.A.; Guntenspergen, G.R.

    2002-01-01

    Historical data have increasingly become appreciated for insight into the past conditions of ecosystems. Uses of such data include assessing the extent of ecosystem change; deriving ecological baselines for management, restoration, and modeling; and assessing the importance of past conditions on the composition and function of current systems. One historical data set of this type is the Public Land Survey (PLS) of the United States General Land Office, which contains data on multiple tree species, sizes, and distances recorded at each survey point, located at half-mile (0.8 km) intervals on a 1-mi (1.6 km) grid. This survey method was begun in the 1790s on US federal lands extending westward from Ohio. Thus, the data have the potential of providing a view of much of the US landscape from the mid-1800s, and they have been used extensively for this purpose. However, historical data sources, such as those describing the species composition of forests, can often be limited in the detail recorded and the reliability of the data, since the information was often not originally recorded for ecological purposes. Forest trees are sometimes recorded ambiguously, using generic or obscure common names. For the PLS data of northern Wisconsin, USA, we developed a method to classify ambiguously identified tree species using logistic regression analysis, using data on trees that were clearly identified to species and a set of independent predictor variables to build the models. The models were first created on partial data sets for each species and then tested for fit against the remaining data. Validations were conducted using repeated, random subsets of the data. Model prediction accuracy ranged from 81% to 96% in differentiating congeneric species among oak, pine, ash, maple, birch, and elm. Major predictor variables were tree size, associated species, landscape classes indicative of soil type, and spatial location within the study region. Results help to clarify ambiguities

  12. Host-plant species conservatism and ecology of a parasitoid fig wasp genus (Chalcidoidea; Sycoryctinae; Arachonia.

    Directory of Open Access Journals (Sweden)

    Michael J McLeish

    Full Text Available Parasitoid diversity in terrestrial ecosystems is enormous. However, ecological processes underpinning their evolutionary diversification in association with other trophic groups are still unclear. Specialisation and interdependencies among chalcid wasps that reproduce on Ficus presents an opportunity to investigate the ecology of a multi-trophic system that includes parasitoids. Here we estimate the host-plant species specificity of a parasitoid fig wasp genus that attacks the galls of non-pollinating pteromalid and pollinating agaonid fig wasps. We discuss the interactions between parasitoids and the Ficus species present in a forest patch of Uganda in context with populations in Southern Africa. Haplotype networks are inferred to examine intraspecific mitochondrial DNA divergences and phylogenetic approaches used to infer putative species relationships. Taxonomic appraisal and putative species delimitation by molecular and morphological techniques are compared. Results demonstrate that a parasitoid fig wasp population is able to reproduce on at least four Ficus species present in a patch. This suggests that parasitoid fig wasps have relatively broad host-Ficus species ranges compared to fig wasps that oviposit internally. Parasitoid fig wasps did not recruit on all available host plants present in the forest census area and suggests an important ecological consequence in mitigating fitness trade-offs between pollinator and Ficus reproduction. The extent to which parasitoid fig wasps exert influence on the pollination mutualism must consider the fitness consequences imposed by the ability to interact with phenotypes of multiple Ficus and fig wasps species, but not equally across space and time.

  13. Mapping and characterizing selected canopy tree species at the Angkor World Heritage site in Cambodia using aerial data.

    Science.gov (United States)

    Singh, Minerva; Evans, Damian; Tan, Boun Suy; Nin, Chan Samean

    2015-01-01

    At present, there is very limited information on the ecology, distribution, and structure of Cambodia's tree species to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., tree height and crown width) of selected tree species found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA) was used (using multiresolution segmentation) to delineate individual tree crowns from very-high-resolution (VHR) aerial imagery and light detection and ranging (LiDAR) data. Crown width and tree height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the trees (Spearman's rho 0.782 and 0.589, respectively). Individual tree crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%), whereas tree crowns delineated using watershed segmentation underestimated the field-measured tree crown widths. Both spectral angle mapper (SAM) and maximum likelihood (ML) classifications were applied to the aerial imagery for mapping of selected tree species. The latter was found to be more suitable for tree species classification. Individual tree species were identified with high accuracy. Inclusion of textural information further improved species identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation) and supervised classification techniques are useful for tree species mapping and for studies of the forest mensuration variables.

  14. Mapping and characterizing selected canopy tree species at the Angkor World Heritage site in Cambodia using aerial data.

    Directory of Open Access Journals (Sweden)

    Minerva Singh

    Full Text Available At present, there is very limited information on the ecology, distribution, and structure of Cambodia's tree species to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., tree height and crown width of selected tree species found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA was used (using multiresolution segmentation to delineate individual tree crowns from very-high-resolution (VHR aerial imagery and light detection and ranging (LiDAR data. Crown width and tree height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the trees (Spearman's rho 0.782 and 0.589, respectively. Individual tree crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%, whereas tree crowns delineated using watershed segmentation underestimated the field-measured tree crown widths. Both spectral angle mapper (SAM and maximum likelihood (ML classifications were applied to the aerial imagery for mapping of selected tree species. The latter was found to be more suitable for tree species classification. Individual tree species were identified with high accuracy. Inclusion of textural information further improved species identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation and supervised classification techniques are useful for tree species mapping and for studies of the forest mensuration variables.

  15. Tree species preferences of foraging songbirds during spring migration in floodplain forests of the Upper Mississippi River

    Science.gov (United States)

    Kirsch, Eileen M.; Wellik, Mike J.

    2017-01-01

    Floodplain forest of the Upper Mississippi River is important for songbirds during spring migration. However, the altered hydrology of this system and spread of reed canary grass (Phalaris arundinacea) and emerald ash borer (Agrilus planipennis) threaten tree diversity and long-term sustainability of this forest. We estimated tree preferences of songbirds during spring migration 2010–2013 to help guide management decisions that promote tree diversity and forest sustainability and to evaluate yearly variation in tree selection. We used the point center-quarter method to assess relative availability of tree species and tallied bird foraging observations on tree species as well as recording the phenophase of used trees on five 40 ha plots of contiguous floodplain forest between La Crosse, Wisconsin and New Albin, Iowa, from 15 April through 1 June. We quantified bird preferences by comparing proportional use of tree species by each bird species to estimates of tree species availability for all 4 y and for each year separately. Species that breed locally preferred silver maple (Acer saccharinum), which is dominant in this forest. The common transient migrant species and the suite of 17 transient wood warbler species preferred hackberry (Celtis occidentalis) and oaks (Quercus spp.), which are limited to higher elevations on the floodplain. We observed earlier leaf development the warm springs of 2010 and 2012 and later leaf development the cold springs of 2011 and 2013. Yellow-rumped Warbler (Setophaga coronata), American Redstart (S. ruticilla), Warbling Vireo (Vireo gilvus) and Baltimore Oriole (Icterus galbula), and the suite of transient migrant wood warblers spread their foraging efforts among tree species in colder springs and were more selective in warmer springs. All three of the important tree species are not regenerating well on the UMR and widespread die-off of silver maple is possible in 50 y without large scale management.

  16. The ratio of K to Ca in thalli of several species of lichens occurring on various trees

    Directory of Open Access Journals (Sweden)

    Stanisława Kuziel

    2015-01-01

    Full Text Available The per cent contents of K and Ca in 7 species of lichens and in the bark: of trees and extracts from this bark were determined. The ratio K : Ca was calculated. In the particular species of lichens collected from the tree the K : Ca ratio varies from 0.05 to 4.93. In the thalli of one species collected from various species of trees the content of cations varies, but the K: Ca ratio is more or less constant in particular species.

  17. Growth of four tropical tree species in petroleum-contaminated soil and effects of crude oil contamination

    NARCIS (Netherlands)

    Pérez-Hernández, I.; Ochoa-Gaona, S.; Adams, R.H.; Rivera-Cruz, M.C.; Pérez-Hernández, V.; Jarquín-Sánchez, A.; Geissen, V.; Martínez-Zurimendi, P.

    2017-01-01

    Under greenhouse conditions, we evaluated establishment of four tree species and their capacity to degrade crude oil recently incorporated into the soil; the species were as follows: Cedrela odorata (tropical cedar), Haematoxylum campechianum (tinto bush), Swietenia macrophylla (mahogany), and

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

    Science.gov (United States)

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

    2015-03-01

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

  19. Variation in phenolic root exudates and rhizosphere carbon cycling among tree species in temperate forest ecosystems

    Science.gov (United States)

    Zwetsloot, Marie; Bauerle, Taryn; Kessler, André; Wickings, Kyle

    2017-04-01

    Temperate forest tree species composition has been highly dynamic over the past few centuries and is expected to only further change under current climate change predictions. While aboveground changes in forest biodiversity have been widely studied, the impacts on belowground processes are far more challenging to measure. In particular, root exudation - the process through which roots release organic and inorganic compounds into the rhizosphere - has received little scientific attention yet may be the key to understanding root-facilitated carbon cycling in temperate forest ecosystems. The aim of this study was to analyze the extent by which tree species' variation in phenolic root exudate profiles influences soil carbon cycling in temperate forest ecosystems. In order to answer this question, we grew six temperate forest tree species in a greenhouse including Acer saccharum, Alnus rugosa, Fagus grandifolia, Picea abies, Pinus strobus, and Quercus rubra. To collect root exudates, trees were transferred to hydroponic growing systems for one week and then exposed to cellulose acetate strips in individual 800 mL jars with a sterile solution for 24 hours. We analyzed the methanol-extracted root exudates for phenolic composition with high-performance liquid chromatography (HPLC) and determined species differences in phenolic abundance, diversity and compound classes. This information was used to design the subsequent soil incubation study in which we tested the effect of different phenolic compound classes on rhizosphere carbon cycling using potassium hydroxide (KOH) traps to capture soil CO2 emissions. Our findings show that tree species show high variation in phenolic root exudate patterns and that these differences can significantly influence soil CO2 fluxes. These results stress the importance of linking belowground plant traits to ecosystem functioning. Moreover, this study highlights the need for research on root and rhizosphere processes in order to improve

  20. Exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nunn, Angela J. [Ecophysiology of Plants, Department of Ecology, Technical University of Muenchen, Am Hochanger 13, D-85354 Freising, Bavaria (Germany)]. E-mail: nunn@wzw.tum.de; Wieser, Gerhard [Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Unit Alpine Timberline Ecophysiology, Rennweg 1, 6020 Innsbruck (Austria); Metzger, Ursula [Ecophysiology of Plants, Department of Ecology, Technical University of Muenchen, Am Hochanger 13, D-85354 Freising, Bavaria (Germany); Loew, Markus [Ecophysiology of Plants, Department of Ecology, Technical University of Muenchen, Am Hochanger 13, D-85354 Freising, Bavaria (Germany); Wipfler, Philip [Forest Yield Science, Technical University of Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Haeberle, Karl-Heinz [Ecophysiology of Plants, Department of Ecology, Technical University of Muenchen, Am Hochanger 13, D-85354 Freising, Bavaria (Germany); Matyssek, Rainer [Ecophysiology of Plants, Department of Ecology, Technical University of Muenchen, Am Hochanger 13, D-85354 Freising, Bavaria (Germany)

    2007-04-15

    Whole-tree O{sub 3} uptake was exemplified for Picea abies, Fagus sylvatica and Larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on O{sub 3} flux. O{sub 3} uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. The responsiveness of the canopy conductance to water vapor and, as a consequence, O{sub 3} uptake to soil moisture and air humidity did not differ between species. Unifying findings at the whole-tree level will promote cause-effect based O{sub 3} risk assessment and modeling. - Sap flow-based assessment of whole-tree O{sub 3} uptake reflects similar responsiveness of canopy conductance and O{sub 3} uptake across contrasting tree species and site conditions.

  1. Tree Density and Species Decline in the African Sahel Attributable to Climate

    Science.gov (United States)

    Gonzalez, Patrick; Tucker, Compton J.; Sy, H.

    2012-01-01

    Increased aridity and human population have reduced tree cover in parts of the African Sahel and degraded resources for local people. Yet, tree cover trends and the relative importance of climate and population remain unresolved. From field measurements, aerial photos, and Ikonos satellite images, we detected significant 1954-2002 tree density declines in the western Sahel of 18 +/- 14% (P = 0.014, n = 204) and 17 +/- 13% (P = 0.0009, n = 187). From field observations, we detected a significant 1960-2000 species richness decline of 21 +/- 11% (P = 0.0028, n = 14) across the Sahel and a southward shift of the Sahel, Sudan, and Guinea zones. Multivariate analyses of climate, soil, and population showed that temperature most significantly (P < 0.001) explained tree cover changes. Multivariate and bivariate tests and field observations indicated the dominance of temperature and precipitation, supporting attribution of tree cover changes to climate variability. Climate change forcing of Sahel climate variability, particularly the significant (P < 0.05) 1901-2002 temperature increases and precipitation decreases in the research areas, connects Sahel tree cover changes to global climate change. This suggests roles for global action and local adaptation to address ecological change in the Sahel.

  2. Tree Species Detection Accuracies Using Discrete Point Lidar and Airborne Waveform Lidar

    Directory of Open Access Journals (Sweden)

    Eric C. Turnblom

    2012-02-01

    Full Text Available Species information is a key component of any forest inventory. However, when performing forest inventory from aerial scanning Lidar data, species classification can be very difficult. We investigated changes in classification accuracy while identifying five individual tree species (Douglas-fir, western redcedar, bigleaf maple, red alder, and black cottonwood in the Pacific Northwest United States using two data sets: discrete point Lidar data alone and discrete point data in combination with waveform Lidar data. Waveform information included variables which summarize the frequency domain representation of all waveforms crossing individual trees. Discrete point data alone provided 79.2 percent overall accuracy (kappa = 0.74 for all 5 species and up to 97.8 percent (kappa = 0.96 when comparing individual pairs of these 5 species. Incorporating waveform information improved the overall accuracy to 85.4 percent (kappa = 0.817 for five species, and in several two-species comparisons. Improvements were most notable in comparing the two conifer species and in comparing two of the three hardwood species.

  3. Discrimination of the Social Parasite Ectatomma parasiticum by Its Host Sibling Species (E. tuberculatum

    Directory of Open Access Journals (Sweden)

    Renée Fénéron

    2013-01-01

    Full Text Available Among social parasites, workerless inquilines entirely depend on their host for survival and reproduction. They are usually close phylogenetic relatives of their host, which raises important questions about their evolutionary history and mechanisms of speciation at play. Here we present new findings on Ectatomma parasiticum, the only inquiline ant described in the Ectatomminae subfamily. Field data confirmed its rarity and local distribution in a facultative polygynous population of E. tuberculatum in Mexico. Genetic analyses demonstrated that the parasite is a sibling species of its host, from which it may have diverged recently. Polygyny is suggested to have favored the evolution of social parasite by sympatric speciation. Nevertheless, host workers from this population were able to discriminate parasites from their conspecifics. They treated the parasitic queens either as individuals of interest or as intruders, depending on their colonial origin, probably because of the peculiar chemical profile of the parasites and/or their reproductive status. We suggest that E. parasiticum could have conserved from its host sibling species the queen-specific substances that produce attracting and settling effect on workers, which, in return, would increase the probability to be detected. This hypothesis could explain the imperfect social integration of the parasite into host colonies.

  4. Association of host and microbial species diversity across spatial scales in desert rodent communities.

    Science.gov (United States)

    Gavish, Yoni; Kedem, Hadar; Messika, Irit; Cohen, Carmit; Toh, Evelyn; Munro, Daniel; Dong, Qunfeng; Fuqua, Clay; Clay, Keith; Hawlena, Hadas

    2014-01-01

    Relationships between host and microbial diversity have important ecological and applied implications. Theory predicts that these relationships will depend on the spatio-temporal scale of the analysis and the niche breadth of the organisms in question, but representative data on host-microbial community assemblage in nature is lacking. We employed a natural gradient of rodent species richness and quantified bacterial communities in rodent blood at several hierarchical spatial scales to test the hypothesis that associations between host and microbial species diversity will be positive in communities dominated by organisms with broad niches sampled at large scales. Following pyrosequencing of rodent blood samples, bacterial communities were found to be comprised primarily of broad niche lineages. These communities exhibited positive correlations between host diversity, microbial diversity and the likelihood for rare pathogens at the regional scale but not at finer scales. These findings demonstrate how microbial diversity is affected by host diversity at different spatial scales and suggest that the relationships between host diversity and overall disease risk are not always negative, as the dilution hypothesis predicts.

  5. Association of host and microbial species diversity across spatial scales in desert rodent communities.

    Directory of Open Access Journals (Sweden)

    Yoni Gavish

    Full Text Available Relationships between host and microbial diversity have important ecological and applied implications. Theory predicts that these relationships will depend on the spatio-temporal scale of the analysis and the niche breadth of the organisms in question, but representative data on host-microbial community assemblage in nature is lacking. We employed a natural gradient of rodent species richness and quantified bacterial communities in rodent blood at several hierarchical spatial scales to test the hypothesis that associations between host and microbial species diversity will be positive in communities dominated by organisms with broad niches sampled at large scales. Following pyrosequencing of rodent blood samples, bacterial communities were found to be comprised primarily of broad niche lineages. These communities exhibited positive correlations between host diversity, microbial diversity and the likelihood for rare pathogens at the regional scale but not at finer scales. These findings demonstrate how microbial diversity is affected by host diversity at different spatial scales and suggest that the relationships between host diversity and overall disease risk are not always negative, as the dilution hypothesis predicts.

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

    Directory of Open Access Journals (Sweden)

    X. Zhou

    2017-12-01

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

  7. Host-parasite interaction between crustaceans of six fish species from the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Huann Carllo Gentil Vasconcelos

    2016-07-01

    Full Text Available Host-parasite interactions between crustaceans and six fish species (Psectrogaster falcata, Ageneiosus ucayalensis, Acestrorhynchus falcirostris, Hemiodus unimaculatus, Serrasalmus gibbus and Geophagus proximus from a reservoir in eastern Amazon, northern Brazil, were investigated. Eight hundred and seventy-eight parasites belonging to three crustacean species, Excorallana berbicensis, Argulus chicomendesi and Ergasilus turucuyus, which parasitized the hosts’ mouth, gills and tegument, were collected from 295 fish and examined. High infestation levels were caused by E. berbicensis on the body surface of the hosts. Excorallana berbicensis showed aggregate dispersion, except in S. gibbus, while E. turucuyus showed random dispersion in A. falcirostris. The host’s sex did not influence infestation by E. berbicensis, and high parasitism failed to affect the body conditions of the fish. In the case of some hosts, rainfall rates, temperature, dissolved oxygen levels and water pH affected the prevalence and abundance of E. berbicensis, the dominant parasite species. Results revealed that the environment and life-style of the hosts were determining factors in infestations by parasites. Current assay is the first report on E. berbicensis for the six hosts, as well as on A. chicomendesi for G. proximus and P. falcata.

  8. Fine root decay rates vary widely among lowland tropical tree species.

    Science.gov (United States)

    Raich, James W; Russell, Ann E; Valverde-Barrantes, Oscar

    2009-08-01

    Prolific fine root growth coupled with small accumulations of dead fine roots indicate rapid rates of fine root production, mortality and decay in young tree plantations in lowland Costa Rica. However, published studies indicate that fine roots decay relatively slowly in tropical forests. To resolve this discrepancy, we used the intact-core technique to quantify first-year decay rates of fine roots in four single-species plantations of native tree species. We tested three hypotheses: first, that fine roots from different tree species would decay at different rates; second, that species having rapid fine root growth rates would also have rapid rates of fine root decay; and third, that differences in fine root decay among species could be explained by fine root chemistry variables previously identified as influencing decay rates. Fine roots in Virola koschnyi plantations decayed very slowly (k = 0.29 +/- 0.15 year(-1)); those of Vochysia guatemalensis decayed seven times faster (k = 2.00 +/- 0.13 year(-1)). Decay rates of the remaining two species, Hieronyma alchorneoides and Pentaclethra macroloba, were 1.36 and 1.28 year(-1), respectively. We found a positive, marginally significant correlation between fine root decay rates and the relative growth rates of live fine roots (R = 0.93, n = 4, P = 0.072). There was a highly significant negative correlation between fine root decay and fine root lignin:N (R = 0.99, P = 0.01), which supports the use of lignin:N as a decay-controlling factor within terrestrial ecosystem models. The decay rates that we observed in this single study location encompassed the entire range of fine root decay rates previously observed in moist tropical forests, and thus suggest great potential for individual tree species to alter belowground organic matter and nutrient dynamics within a biotically rich rainforest environment.

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

    Science.gov (United States)

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

    2010-12-01

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

  10. Project CAPTURE: a U.S. national prioritization assessment of tree species for conservation, management, and restoration

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane; Valerie D. Hipkins

    2017-01-01

    that forest tree species will undergo population-level extirpation or species-level extinction during the next century. Project CAPTURE (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) is a cooperative effort across the three U.S. Department of Agriculture Forest Service (USDA FS) deputy areas to establish a framework for...

  11. Simulated effects of climate change, fragmentation, and inter-specific competition on tree species migration in northern Wisconsin, USA

    Science.gov (United States)

    Robert M. Scheller; David J. Mladenoff

    2008-01-01

    The reproductive success, growth, and mortality rates of tree species in the northern United States will be differentially affected by projected climate change over the next century. As a consequence, the spatial distributions of tree species will expand or contract at differential rates. In addition, human fragmentation of the landscape may limit effective seed...

  12. Project CAPTURE: using forest inventory and analysis data to prioritize tree species for conservation, management, and restoration

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane; William W. Hargrove

    2015-01-01

    A variety of threats, most importantly climate change and insect and disease infestation, will increase the likelihood that forest tree species could experience population-level extirpation or species-level extinction during the next century. Project CAPTURE (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) is a cooperative effort...

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  14. Allometric models for aboveground biomass of ten tree species in northeast China

    Directory of Open Access Journals (Sweden)

    Shuo Cai

    2013-07-01

    Full Text Available China contains 119 million hectares of natural forest, much of which is secondary forest. An accurate estimation of the biomass of these forests is imperative because many studies conducted in northeast China have only used primary forest and this may have resulted in biased estimates. This study analyzed secondary forest in the area using information from a forest inventory to develop allometric models of the aboveground biomass (AGB. The parameter values of the diameter at breast height (DBH, tree height (H, and crown length (CL were derived from a forest inventory of 2,733 trees in a 3.5 ha plot. The wood-specific gravity (WSG was determined for 109 trees belonging to ten species. A partial sampling method was also used to determine the biomass of branches (including stem, bark and foliage in 120 trees, which substantially easy the field works. The mean AGB was 110,729 kg ha–1. We developed four allometric models from the investigation and evaluated the utility of other 19 published ones for AGB in the ten tree species. Incorporation of full range of variables with WSG-DBH-H-CL, significantly improved the precision of the models. Some of models were chosen that best fitted each tree species with high precision (R2 = 0.939, SEE 0.167. At the latitude level, the estimated AGBof secondary forest was lower than that in mature primary forests, but higher than that in primary broadleaf forest and the average level in other types of forest likewise. 

  15. Ecophysiological evaluation of tree species for biomonitoring of air quality and identification of air pollution-tolerant species.

    Science.gov (United States)

    Sen, Abhishek; Khan, Indrani; Kundu, Debajyoti; Das, Kousik; Datta, Jayanta Kumar

    2017-06-01

    Identification of tree species that can biologically monitor air pollution and can endure air pollution is very much important for a sustainable green belt development around any polluted place. To ascertain the species, ten tree species were selected on the basis of some previous study from the campus of the University of Burdwan and were studied in the pre-monsoon and post-monsoon seasons. The study has been designed to investigate biochemical and physiological activities of selected tree species as the campus is presently exposed to primary air pollutants and their impacts on plant community were observed through the changes in several physical and biochemical constituents of plant leaves. As the plant species continuously exchange different gaseous pollutants in and out of the foliar system and are very sensitive to gaseous pollutants, they serve as bioindicators. Due to air pollution, foliar surface undergoes different structural and functional changes. In the selected plant species, it was observed that the concentration of primary air pollutants, proline content, pH, relative water holding capacity, photosynthetic rate, and respiration rate were higher in the pre-monsoon than the post-monsoon season, whereas the total chlorophyll, ascorbic acid, sugar, and conductivity were higher in the post-monsoon season. From the entire study, it was observed that the concentration of sulfur oxide (SO x ), nitrogen oxide (NO x ), and suspended particulate matter (SPM) all are reduced in the post-monsoon season than the pre-monsoon season. In the pre-monsoon season, SO x , NO x , and SPM do not have any significant correlation with biochemical as well as physiological parameters. SPM shows a negative relationship with chlorophyll 'a' (r = -0.288), chlorophyll 'b' (r = -0.267), and total chlorophyll (r = -0.238). Similarly, chlorophyll a, chlorophyll b, and the total chlorophyll show negative relations with SO x and NO x (p air pollution tolerance index (APTI

  16. Niche segregation and genetic structure of Campylobacter jejuni populations from wild and agricultural host species.

    Science.gov (United States)

    Sheppard, Samuel K; Colles, Frances M; McCarthy, Noel D; Strachan, Norval J C; Ogden, Iain D; Forbes, Ken J; Dallas, John F; Maiden, Martin C J

    2011-08-01

    Bacterial populations can display high levels of genetic structuring but the forces that influence this are incompletely understood. Here, by combining modelling approaches with multilocus sequence data for the zoonotic pathogen Campylobacter, we investigated how ecological factors such as niche (host) separation relate to population structure. We analysed seven housekeeping genes from published C. jejuni and C. coli isolate collections from a range of food and wild animal sources as well as abiotic environments. By reconstructing genetic structure and the patterns of ancestry, we quantified C. jejuni host association, inferred ancestral populations, investigated genetic admixture in different hosts and determined the host origin of recombinant C. jejuni alleles found in hybrid C. coli lineages. Phylogenetically distinct C. jejuni lineages were associated with phylogenetically distinct wild birds. However, in the farm environment, phylogenetically distant host animals shared several C. jejuni lineages that could not be segregated according to host origin using these analyses. Furthermore, of the introgressed C. jejuni alleles found in C. coli lineages, 73% were attributed to genotypes associated with food animals. Our results are consistent with an evolutionary scenario where distinct Campylobacter lineages are associated with different host species but the ecological factors that maintain this are different in domestic animals such that phylogenetically distant animals can harbour closely related strains. © 2011 Blackwell Publishing Ltd.

  17. Temporal variability of stemflow volume in a beech-yellow poplar forest in relation to tree species and size

    Science.gov (United States)

    Levia, D. F.; Van Stan, J. T., II; Mage, S. M.; Kelley-Hauske, P. W.

    2010-01-01

    SummaryStemflow has distinguishable effects on the hydrology and biogeochemistry of wooded ecosystems. Nonetheless, it is a relatively poorly understood hydrologic process. No known studies have investigated the temporal variability of stemflow volume at 5-min intervals in a beech-yellow poplar forest of eastern North America. The aim of this research is to compare the temporal variability of stemflow generation by Fagus grandifolia Ehrh. (American beech) and Liriodendron tulipifera L. (yellow poplar) in relation to tree species and size. Employing a dense network of tipping-bucket stemflow gages interfaced with a datalogger, a 5 min stemflow yield database was assembled and analyzed to better discern how stemflow production varies (temporally) with tree species and size. Results indicate that both tree species and size have detectable effects on the temporal variability of stemflow yield. Observational data, scientific analysis, and correspondence analysis reveals that stemflow yield: (1) is more similar within than between the two tree species with differences likely being attributable to differences in bark texture and water storage capacity; (2) tree size affects stemflow yield within species; (3) rain event characteristics affect stemflow yield; and (4) stemflow yield for particular trees and rain events is the result of a complex set of interactions among tree species, tree size, and meteorological conditions. These results suggest that the temporal variation in stemflow yield from co-occurring forest trees may play a significant role in subsurface drainage of wooded ecosystems during rain events.

  18. (macro- Evolutionary ecology of parasite diversity: From determinants of parasite species richness to host diversification

    Directory of Open Access Journals (Sweden)

    Serge Morand

    2015-04-01

    Full Text Available The present review summarized the factors or determinants that may explain parasite diversity among host species and the consequences of this parasite diversity on the evolution of host-life history traits. As host–parasite interactions are asymmetrical exploited–exploiter relationships, ecological and epidemiological theories produce hypotheses to find the potential determinants of parasite species richness, while life-history theory helps for testing potential consequences on parasite diversity on the evolution of hosts. This review referred only to studies that have specifically controlled or took into account phylogenetic information illustrated with parasites of mammals. Several points needing more investigation were identified with a special emphasis to develop the metabolic theory of epidemiology.

  19. Methods to Evaluate Host Tree Suitability to the Asian Long horned Beetle, Anoplophora glabripennis

    Science.gov (United States)

    Scott W. Ludwig; Laura Lazarus; Deborah G. McCullough; Kelli Hoover; Silvia Montero; James C. Sellmer

    2002-01-01

    Two procedures were evaluated for assessing tree susceptibility to Anaplophora glabripennis. In the first procedure, adult beetles were caged with a section of sugar maple, northern red oak, white oak, honeylocust, eastern cottonwood, sycamore or tulip poplar wood Results showed that females laid viable eggs on sugar maple, red oak, white oak and...

  20. Host-tree monoterpenes and biosynthesis of aggregation pheromones in the bark beetle ips paraconfusus

    Science.gov (United States)

    In the 1970-80s, vapors of the common conifer tree monoterpenes, myrcene and a-pinene, were shown to serve as precursors of ipsenol, ipsdienol and cis-verbenol, aggregation pheromone components of Ips paraconfusus. A paradigm developed that Ips bark beetles utilize pre-formed monoterpene precursors ...

  1. Feeding behavior of two exotic aphid species on their original hosts in a new invaded area.

    Science.gov (United States)

    Lazzarotto, C M; Lazzari, S M N; Penteado, S R C

    2011-01-01

    Greenidea ficicola Takahashi and Greenidea psidii van der Goot (Aphididae: Greenideinae) are Asian aphid species newly introduced in Brazil associated with Moraceae and Myrtaceae. The feeding behavior of G. ficicola and G. psidii was investigated on their respective host plants, Ficus benjamina (Moraceae) and Psidium guajava (Myrtaceae), using the Electrical Penetration Graph (EPG). Fifteen females of each aphid species were monitored during 24h using a DC-EPG GIGA-4 monitor. The time spent in phloem phase (waveforms E1 and E2) was 13.6% of the total recording time for G. ficicola and 0.8% for G. psidii. The average time in the pathway phase (waveforms C and pd) represented 50% of the total time for both species. Aphids spent more time in non-penetration and stylet pathway activities than in the phloem phase or actual feeding. The principal component analysis (PCA) showed that the two species formed different groups in relation to EPG parameters, despite some overlapping. The probing patterns with multiple penetrations of short duration in the sieve elements for both species may indicate apparent unsuitability for sustained feeding on their respective host plants. These results suggest that these two exotic species are in the process of adaptation to their host plants in their new environment and/or the plants may present either chemical or physical barriers against these insects.

  2. Validation of a model for prediction of host damage by two nematode species.

    Science.gov (United States)

    Duncan, L W; Ferris, H

    1983-04-01

    PLANT ROOTS WERE MECHANICALLY INJURED OR SUBJECTED TO NEMATODE PARASITISM TO TEST THE MODEL OF HOST DAMAGE BY TWO NEMATODE SPECIES: y = m' + (l - m')c'z(P)z(P) for y 1.0, where m' = m + (m - m) (1 - y)/[(1 - y) + (l - y)] and c' = (z(-T) + z(-T))/2. Damage functions for greenhouse-grown radish plants (cv. Cherry Belle) mechanically injured with small or large steel needles were used to predict growth of plants injured by both needles. Growth predictions accounted for 94%, 87%, and 82% of mean treatment variation in plant height, stem weight, and root weight, respectively. Cowpea (cv. California Blackeye No. 5) damage functions, based on preplant population levels of Meloidogyne incognita and M. javanica, were used to predict seed yield of plants concomitantly infected with various levels of each species. Single species damage functions and population growth curves indicated significant host resistance to M. incognita and significantly lower virulence of that species compared to M. javanica. Model predictions accounted for 88% of mean seed yield variation in two-species treatments. In a separate experiment, mean top weights of 30-day-old cowpea plants, nniformly inoculated with 20,000 M. javanica eggs, increased with increasing levels of concomitantly inoculated M. incognita eggs. It is speculated that competitive interactions between M. incognita and M. javanica mitigated host damage by the more virulent species.

  3. Geographic analysis of host use, development, and habitat use of an acanthocephalan species, Leptorhynchoides thecatus.

    Science.gov (United States)

    Steinauer, Michelle L; Parham, James E; Nickol, Brent B

    2006-06-01

    Leptorhynchoides thecatus (Linton, 1891), an acanthocephalan parasite of freshwater fishes, varies in host use, development, and habitat use throughout North America. Spatial structure of these characteristics was examined from data extracted from the literature. Geographic patterns were inferred from point comparisons using correllograms and then tested with Moran's I statistic for global and local significance, and visually from regional means within major river drainages. Species of Micropterus Lacepède, 1802 (black basses) were common hosts in most regions, except the Lower Mississippi and South Atlantic regions where species of Lepomis Rafinesque, 1819 (sunfishes) were common hosts. Development, described as the proportions of adults relative to cystacanths (extraintestinal juveniles), decreased with latitude. Habitat use of L. thecatus showed marked geographic patterns. Leptorhynchoides thecatus occurred in the intestine of sunfishes in the South Atlantic and Lower Mississippi regions, in the ceca in fish of all species included in the study in the Missouri and Texas-Gulf regions, and both in ceca and intestines in fish of all species in northern regions. Leptorhynchoides thecatus showed geographic patterning within the variable traits across the range of the species. These patterns may be the result of ecological factors or of genetic differences that might indicate L. thecatus comprises multiple cryptic species.

  4. Patterns and determinants of wood physical and mechanical properties across major tree species in China.

    Science.gov (United States)

    Zhu, JiangLing; Shi, Yue; Fang, LeQi; Liu, XingE; Ji, ChengJun

    2015-06-01

    The physical and mechanical properties of wood affect the growth and development of trees, and also act as the main criteria when determining wood usage. Our understanding on patterns and controls of wood physical and mechanical properties could provide benefits for forestry management and bases for wood application and forest tree breeding. However, current studies on wood properties mainly focus on wood density and ignore other wood physical properties. In this study, we established a comprehensive database of wood physical properties across major tree species in China. Based on this database, we explored spatial patterns and driving factors of wood properties across major tree species in China. Our results showed that (i) compared with wood density, air-dried density, tangential shrinkage coefficient and resilience provide more accuracy and higher explanation power when used as the evaluation index of wood physical properties. (ii) Among life form, climatic and edaphic variables, life form is the dominant factor shaping spatial patterns of wood physical properties, climatic factors the next, and edaphic factors have the least effects, suggesting that the effects of climatic factors on spatial variations of wood properties are indirectly induced by their effects on species distribution.

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

    Directory of Open Access Journals (Sweden)

    Guodong Jia

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

  6. Estimating the global conservation status of more than 15,000 Amazonian tree