Biological diversity constitutes the very foundation of human existence and it is yet clear that besides profound ethical and aesthetic implications, the global loss of biodiversity associated with the expansion of human activity has serious economic and social costs. Additionally, recent publications underline the importance of biodiversity for ecosystem functioning, although the interpretation of experiments on the relationship between species diversity and ecosystem processes has been controversial (for an overview see Loreau et al. 2002).
For very practical reasons, the experimental/observational model systems used in these studies were small-statured, short-lived and even-aged, in large, herbaceous assemblages. Results obtained with these systems have enormously stimulated the scientific debate, have underlined the plausibility of a great deal of theory, and in essence supported the view that biological richness does influence ecosystem function beyond the keystone species effect (a certain species dominating the system's function). This was attributed to niche complementarity, facilitation, and other forms of mutualism. With careful replication of different multi-species assemblages the so-called sampling effect (a productive species more likely to be present in a species rich assemblage) could be ruled out as the single explanation of enhanced functioning (e.g. productivity) of multi-species assemblages.
However, the translation, application, and confirmation of such findings to other community and ecosystem types has been found difficult. There is no obvious reason, why such functional links between diversity and function should not exist in forests, which store 80% of the biomass carbon of the planet.
Here, we propose a new biodiversity - ecosystem function experiment with tree species, using the "synthetic community approach", i.e. establishing communities differing in diversity by planting.
Loreau, M., S. Naeem, and P. Inchausti, eds. Biodiversity and ecosystem functioning: Synthesis and perspectives.2002, Oxford University Press: Oxford, New York. 294.
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