Forest Ecosystems, Analysis at Multiple Scales, 2nd Edition

Abstract

This chapter analyzes the forest ecosystem at the level of individual stands and gradually expands the time and space scales. A forest ecosystem includes the living organisms of the forest, and it extends vertically upward into the atmospheric layer enveloping forest canopies and downward to the lowest soil layers affected by roots and biotic processes. Ecosystem analysis is a mix of biogeochemistry, ecophysiology, and micrometeorology that emphasizes “the circulation, transformation, and accumulation of energy and matter through the medium of living things and their activities.” Ecosystem ecology is less concerned with species diversity than with the contribution that any complex of species makes to the water, carbon, energy, and nutrient transfer in the landscape. Ecosystem studies consider not only the flux of energy and materials through a forest, but also the transformations that occur within the forest. Forest ecosystems are open systems in the sense that they exchange energy and materials with other systems, including adjacent forests, aquatic ecosystems, and the atmosphere. The exchange is essential for the continued persistence of the ecosystem. A forest ecosystem is never in complete equilibrium, a term appropriate only to closed systems in the laboratory.