Biodiversity, carbon storage, and productivity of the world's tropical forests.

Supervisors: Oliver Phillips, Simon Lewis This project will be a CASE project in collaboration with staff at the UNEP World Conservation Monitoring Centre (WCMC), led by Dr Jörn Scharlemann Tropical forests are species-rich, carbon-dense and highly productive ecosystems. They play globally important roles in (i) biodiversity conservation and (ii) modifying the rate of human-induced climate change. Current efforts to mitigate climate change have renewed focus on tropical forests. Specifically, schemes are being planned under which developing countries will receive payments if deforestation rates and hence carbon fluxes to the atmosphere are reduced. However, it is currently unknown how such investments to mitigate climate change - requiring preserving forests with the largest standing stocks of carbon - may affect other priorities, such as biodiversity conservation. Therefore, from both policy and scientific viewpoints, understanding how tree diversity, carbon storage and forest productivity vary within tropical forests, and the mechanistic links between them, is both extremely timely and important. This project will tackle three of the most important outstanding scientific questions, namely (1) the issue of whether or not the most carbon-dense and/or productive forests are also in fact the most diverse (species diversity and phylogenetic diversity), (2) whether high biodiversity per se is a factor that actually boosts carbon storage and productivity, since diversity may help to maximise ecosystem-level resource-use efficiencies, or alternatively whether any relationship between the two is simply coincidental, and (3) whether the size of the current net carbon sink in a given tropical forest is partially determined by its diversity. We have (and are further developing) a unique database making it possible to tackle these questions across the world's tropical forests for the first time, with long-term records from >350 plots in Amazonia, Africa, Asia, and Australia. The student will use data on biomass, growth, and wood density to estimate site biomass, productivity and tree diversity, and apply these estimates to determine how biomass and productivity vary with diversity (cf Keeling & Phillips 2007). Relationships between diversity and ecosystem function are complicated by two-way causality and by co-varying environmental variables; a range of statistical techniques will need to be applied to quantify and control for such factors. The student will also take part in a field campaign in Guyana and then later lead a similar expedition in Gabon, which will develop complementary skills and allow him/her to test the prediction that relatively low diversity forests have low productivity. Addressing these questions will have policy implications: by revealing the linkages between diversity and ecosystem services this work will inform conservation policy and will help governments and scientists alike quantify the potential synergies between managing and protecting forests for biodiversity and for carbon storage. The successful candidate will have some background in advanced statistical analysis and ecological theory, and will be motivated to pursue a career in ecology or conservation policy. WCMC will provide support of £2K p/a. WCMC will ensure the student fully understands the policy issues in biodiversity conservation and climate change and the complex intersections of both, so that the outputs include not only world-class science but also have specific policy relevance. This research will be highly policy-relevant, especially to the UN-REDD (Reduced Emissions from Deforestation and Degradation) Programme which WCMC contributes. Furthermore, as WCMC is part of the UN, whilst being strongly involved with international NGOs, collaboration will help the student to ensure their work is complementary to other ongoing efforts, relevant to current policy needs, and important findings are taken up by key decision makers