Understanding biodiversity maintenance and change across local, regional and global forests

点击翻译按钮获取中文摘要

Knowledge on biodiversity maintenance and change in landscapes is essential for predicting ecosystem responses to natural and anthropogenic disturbances, thus informing biodiversity conservation and management. However, current evidence on diversity change is equivocal and understanding of the mechanisms that maintain or drive changes in biodiversity remains limited. This proposal will address these knowledge gaps by undertaking an innovative research program. Built on two long-term and well-designed global networks of forest inventory plots (the CTFS-ForestGEO and National Forest Inventory plots), this research will take observational, experimental and analytical approaches to: test mechanisms of biodiversity maintenance; develop methods for assessing biodiversity change; and, analyze long-term and global forest dynamic data to synthesize understanding of changes in biodiversity and ecosystem functioning. Primarily, this proposal will address four interrelated research components critical to understanding biodiversity maintenance and change in landscapes. (1) Testing the role of soil-borne pathogens in regulating local forest diversity, particularly rare species populations. Field-based warming experiments will be conducted to test how global warming may affect soil pathogen-plant host interactions for understanding potential impacts of climate change on pathogen-regulated biodiversity. (2) Developing statistically sound and ecologically meaningful methods for assessing biodiversity change, and applying these methods to analyze data from the two global forest plots to detect signals of biodiversity change from local to global scales. (3) Quantifying the relative importance of competition and climate to forest dynamics, with a special interest in modeling the interaction of competition and climate for understanding how climate change may mediate tree competition in forests worldwide. (4) Modeling the relationships between tree demographic rates (growth, mortality and recruitment) and ecosystem functioning across global forests. In contrast with the widely adopted but controversial research approach that focuses on biodiversity-ecosystem functioning relationships, this analysis will link ecosystem function with tree demographic processes. Results from this analysis are expected to provide new mechanistic understanding of the effect of forest dynamics on ecosystem functioning. This research program will contribute new knowledge on the mechanisms of biodiversity maintenance and will provide evidence on global biodiversity change (or no change) in forests across spatial scales. The concepts, models, methods and syntheses developed as a result of this work will enhance our ability to understand and predict the impact of climate and land-use change on forest dynamics and functioning for better conservation and management of biodiversity.