The Regulation of Chemical Budgets Over the Course of Terrestrial Ecosystem Succession

Abstract

Vitousek & Reiners (158) have suggested that change in net ecosystem production is a major determinant of the balance between inputs and out­ puts of elements in terrestrial ecosystems. They argued that in the course of primary succession element outputs are initially relatively high (approx­ imating inputs), that they then drop to a minimum because of element accumulation in biomass and detritus when net ecosystem production is highest, and that eventually output rates rise again approximately to equal inputs in late succession when net ecosystem production approaches zero (Figure 1). In most cases of secondary succession, net ecosystem production is negative immediately following disturbance, and in such cases output rates can exceed input rates. The probable importance of change in net ecosystem production is supported in particular by observations of higher element outputs from later successional ecosystems (22, 90, 1'57-159) and