BIODIVERSITY AND ECOSYSTEM FUNCTION

In at least some circumstances, biodiversity affects various ecosystem functions and the ways in which ecosystems respond to disturbance, Be cause these interactions occur at many spatial and temporal scales and throughout all levels of biological organization, it is difficult to decide where to focus attention on interactions between biodiversity a nd ecosystem function. The loci for initial attention is important for setting research priorities to understand these interactions further; for organizing known information to instruct the development of natur al resource policies, and for identifying biodiversity conversation pr iorities. Holling (1992) argues that ecosystem behavior can be underst ood from a few dominating ecological processes that structure the ecos ystem. In the temporal dimension, these key structuring processes dict ate a few dominant temporal frequencies that drive other processes, Th us, the most effective strategy for studying interactions between biod iversity and ecosystem function is to focus on the key structuring pro cesses at intermediate scales of space and time. Thereafter, other eco logical conditions signify situations in which the interactions betwee n biodiversity and ecosystem function are particularly strong: early t o midsuccessional status, low soil fertility, intermediate levels of d isturbance, biotic interactions only where there is collaborative indi cation of importance, invading species that differ significantly from native species in resource ce acquisition or utilization, and ecotones .