8 - How Does Biodiversity Control Primary Productivity?

Abstract

Primary productivity as well as other ecosystem processes associated with the transfer of energy, water, and nutrient are either directly dependent on or are tightly controlled by the activity of organisms present in the ecosystem. Despite early considerations on the positive impact of diversity on biomass production, or on the stability of populations and ecosystem processes, the study of the functional role of biodiversity was less studied. However, with the realization that human alteration of ecosystems is substantial, and may impair the services ecosystems provide to society, linking biodiversity and ecosystem functioning has recently received considerable attention. The biodiversity issue is of great concern for ethical, aesthetic, economic, and ecological reasons. Estimating the intensity of ecological impact of changes in biodiversity has been an active area for research during the past decade. It has been demonstrated that different aspects of diversity are not neutral with respect to ecosystem functioning, but major issues are still to be addressed. However, several biological traits are often involved in the relation between diversity and ecosystem processes. In that case, the determination of a synthetic phenotypic distance is not obvious, and the genotypes, species, and functional group classifications have some relevance. Stability of ecosystem processes and its control by diversity need to be examined in a larger array of conditions. The response of the different ecosystem processes may not be the same, and some perturbations may be more buffered by diversity than others. In particular, patterns of response to abiotic vs. biotic perturbations need to be compared.