248 research outputs found

    Contrasting growth responses to aluminium addition among populations of the aluminium accumulator Melastoma malabathricum

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    Acknowledgements: The authors are grateful to Dr Weitz Hedda, Dr John Danku and Mr. David Hadwen for their help during this research. Sources of Funding: This research was funded by Ministry of Higher Education of Malaysia (MOHE) under SLAB/SLAI scheme and University of Aberdeen research grantPeer reviewedPublisher PD

    Improving the usability of spatial point process methodology: an interdisciplinary dialogue between statistics and ecology

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    The last few decades have seen an increasing interest and strong development in spatial point process methodology, and associated software that facilitates model fitting has become available. A lot of this progress has made these approaches more accessible to users, through freely available software. However, in the ecological user community the methodology has only been slowly picked up despite its obvious relevance to the field. This paper reflects on this development, highlighting mutual benefits of interdisciplinary dialogue for both statistics and ecology. We detail the contribution point process methodology has made to research on biodiversity theory as a result of this dialogue and reflect on reasons for the slow take-up of the methodology. This primarily concerns the current lack of consideration of the usability of the approaches, which we discuss in detail, presenting current discussions as well as indicating future directions

    Symbiotic control of canopy dominance in subtropical and tropical forests

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    Acknowledgments This work was supported by a grant from the Natural Environment Research Council (NERC), ref: NE/R004986/1.Peer reviewedproo

    Leaf traits of dipterocarp species with contrasting distributions across a gradient of nutrient and light availability

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    Background: Tree species composition at the landscape scale is often tightly associated with underlying soil type in tropical forests. Changes in soil type may have effects on forest structure that drive changes in both light and soil resource availability, since light availability in the understorey tends to be lower in more fertile sites. Plant functional traits may determine species distributions across gradients of light and soil resource availability.  Aims: To test whether tree species with contrasting distributions exhibit leaf traits that reflect adaptation to the resources most limiting in their native environment.  Methods: We measured foliar nutrient concentrations, stomatal density, leaf δ13C values, leaf mass per area, and leaf lifespan for saplings of nine common dipterocarp species at Sepilok Forest Reserve, Malaysian Borneo, possessing varying associations to soil resource habitats.  Results: Species specialised in their adult distribution to nutrient-poor sandstone soils had traits indicative of a nutrient conservation strategy. Species specialised to more fertile alluvial soils had a wider spectrum of leaf N and P concentrations and LL, reflecting greater variance in strategies for resource acquisition and use among species in this habitat.  Conclusions: Understorey light regimes co-vary with soil type, and both light and soil resource availability influence leaf trait adaptations that may contribute to species–habitat associations

    Leaf venation networks of Bornean trees: images and hand-traced segmentations.

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    The data set contains images of leaf venation networks obtained from tree species in Malaysian Borneo. The data set contains 726 leaves from 295 species comprising 50 families, sampled from eight forest plots in Sabah. Image extents are approximately 1 × 1 cm, or 50 megapixels. All images contain a region of interest in which all veins have been hand traced. The complete data set includes over 30 billion pixels, of which more than 600 million have been validated by hand tracing. These images are suitable for morphological characterization of these species, as well as for training of machine-learning algorithms that segment biological networks from images. Data are made available under the Open Data Commons Attribution License. You are free to copy, distribute, and use the database; to produce works from the database; and to modify, transform, and build upon the database. You must attribute any public use of the database, or works produced from the database, in the manner specified in the license. For any use or redistribution of the database, or works produced from it, you must make clear to others the license of the database and keep intact any notices on the original database

    Emerging trends in appropriate kiln designs for small-scale biochar production in low to middle income countries

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    This being part of PhD work being funded by the Commonwealth Scholarship Commission and the Foreign, Commonwealth and Development Office in the UK, we are grateful for their support. We also thank the medical illustration team from the University of Aberdeen for professionalizing the diagrams.Peer reviewedPublisher PD

    Neighborhood and community interactions determine the spatial pattern of tropical tree seedling survival

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    Factors affecting survival and recruitment of 3531 individually mapped seedlings of Myristicaceae were examined over three years in a highly diverse neotropical rain forest, at spatial scales of 1–9 m and 25 ha. We found convincing evidence of a community compensatory trend (CCT) in seedling survival (i.e., more abundant species had higher seedling mortality at the 25-ha scale), which suggests that density-dependent mortality may contribute to the spatial dynamics of seedling recruitment. Unlike previous studies, we demonstrate that the CCT was not caused by differences in microhabitat preferences or life history strategy among the study species. In local neighborhood analyses, the spatial autocorrelation of seedling survival was important at small spatial scales (1–5 m) but decayed rapidly with increasing distance. Relative seedling height had the greatest effect on seedling survival. Conspecific seedling density had a more negative effect on survival than heterospecific seedling density and was stronger and extended farther in rare species than in common species. Taken together, the CCT and neighborhood analyses suggest that seedling mortality is coupled more strongly to the landscape-scale abundance of conspecific large trees in common species and the local density of conspecific seedlings in rare species. We conclude that negative density dependence could promote species coexistence in this rain forest community but that the scale dependence of interactions differs between rare and common species

    Growth rings in tropical trees : role of functional traits, environment, and phylogeny

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    Acknowledgments Financial support of the Centre National de la Recherche Scientifique (USR 3330), France, and from the Rufford Small Grants Foundation (UK) is acknowledged. We thank the private farmers and coffee plantation companies of Kodagu for providing permissions and logistical support for this project. We are grateful to N. Barathan for assistance with slide preparation and data entry, S. Aravajy for botanical assistance, S. Prasad and G. Orukaimoni for technical inputs, and A. Prathap, S. Shiva, B. Saravana, and P. Shiva for field assistance. The corresponding editor and three anonymous reviewers provided insightful comments that improved the manuscript.Peer reviewedPostprin
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