Examinando por Autor "Laffan, S.W."

Mostrando 1 - 2 de 2
  • Miniatura
    ÍtemAcceso Abierto
    Carbon isotopic signatures of soil organic matter correlate with leaf area index across woody biomes
    (Blackwell Publishing Ltd, 2014) Ladd, B.; Peri, P.L.; Pepper, D.A.; Silva, L.C.R.; Sheil, D.; Bonser, S.P.; Laffan, S.W.; Amelung, W.; Ekblad, A.; Eliasson, P.; Bahamonde, H.; Duarte-Guardia, S.; Bird, M.
    1. Leaf area index (LAI), a measure of canopy density, is a key variable for modelling and understanding primary productivity, and also water use and energy exchange in forest ecosystems. However, LAI varies considerably with phenology and disturbance patterns, so alternative approaches to quantifying stand-level processes should be considered. The carbon isotope composition of soil organic matter (δ13CSOM) provides a time-integrated, productivity-weighted measure of physiological and stand-level processes, reflecting biomass deposition from seasonal to decadal time scales. 2. Our primary aim was to explore how well LAI correlates with δ13CSOM across biomes. 3. Using a global data set spanning large environmental gradients in tropical, temperate and boreal forest and woodland, we assess the strength of the correlation between LAI and δ13CSOM; we also assess climatic variables derived from the WorldClim database. 4. We found that LAI was strongly correlated with δ13CSOM, but was also correlated with Mean Temperature of the Wettest Quarter, Mean Precipitation of Warmest Quarter and Annual Solar Radiation across and within biomes. 5. Synthesis. Our results demonstrate that δ13CSOM values can provide spatially explicit estimates of leaf area index (LAI) and could therefore serve as a surrogate for productivity and water use. While δ13CSOM has traditionally been used to reconstruct the relative abundance of C3 versus C4 species, the results of this study demonstrate that within stable C3- or C4-dominated biomes, δ13CSOM can provide additional insights. The fact that LAI is strongly correlated to δ13CSOM may allow for a more nuanced interpretation of ecosystem properties of palaeoecosystems based on palaeosol 13C values. © 2014 The Authors.
  • Miniatura
    ÍtemAcceso Abierto
    How are soil carbon and tropical biodiversity related?
    (Cambridge University Press, 2016) Sheil, D.; Ladd, B.; Silva, L.C.R.; Laffan, S.W.; Van Heist, M.
    This article discusses how biological conservation can benefit from an understanding of soil carbon. Protecting natural areas not only safeguards the biota but also curtails atmospheric carbon emissions. Opportunities for funding biological conservation could potentially be greater if soil carbon content is considered. In this article current knowledge concerning the magnitude and vulnerability of soil carbon stocks is reviewed and the relationship of these stocks to biological conservation values is explored. Looking at two relatively well-studied tropical regions we find that 15 of 21 animal species of conservation concern in the Virunga Landscape (Central Africa), and nine of ten such species in the Federal District of Brazil (Central Brazil), rely on carbon-rich habitats (alluvial and/or wetlands). At national scales, densities of species, endemics and threatened taxa (plants, mammals, birds, reptiles, amphibians and fish) show positive and significant relations with mean soil carbon content in all but two cases (threatened amphibians and threatened fish). Of more than 1000 threatened species in 37 selected tropical nations, 85% rely on carbon-rich habitats. This tendency is observed in plants, mammals, reptiles, amphibians and crustaceans, while birds appear more evenly distributed. Research to clarify and explore these relationships is needed. Soil carbon offers major opportunities for conservation. © Foundation for Environmental Conservation 2016.