The analysis of biodiversity experiments: From pattern toward mechanism

© Oxford University Press 2009. All rights reserved. Meta-analysis of the first generation of biodiversity experiments has revealed that there is a general positive relationship between diversity and ecosystem processes that is consistent across trophic groups and ecosystem types. However, the mechanisms generating these general patterns are still under debate. While there are unresolved conceptual issues about the nature of diversity and complementarity, the debate is partly due to the difficulty of performing a full-factorial analysis of the functional effects of all species in a diverse community. However, there are now several different analytical approaches that can address mechanisms even when full factorial analysis is not possible. This chapter presents an overview and users' guide to these methods. This chapter concludes that the current toolbox of methods allows investigation of the mechanisms for most, if not all, biodiversity and ecosystem functioning experiments conducted to date that manipulate species within a single trophic level (e.g. plant biodiversity experiments). Methods that can address mechanisms in multitrophic studies are a key need for future research.