Chapter 47. Species Interactions, Communities, and Ecosystems

47.5 Ecosystems

A community of organisms and the physical environment it occupies together form an ecosystem (Fig. 47.15). The physical and biological components of ecosystems are linked by the processes that cycle nutrients and transfer energy through the system. In Chapter 25, we introduced the concepts of the food web as a depiction of carbon cycling through ecosystems. Now we can revisit this concept and add to it the idea of energy flow through a community, understanding both as reflections of the functional properties of individual species and the interactions among species within a community.

FIG. 47.15 A savanna ecosystem in Africa. The ecosystem includes the grasses, trees, animals, and microorganisms in the community, as well as the climate, soil chemistry, and other features that define its physical environment.

Quick Check 5 What is the difference between a community and an ecosystem?

Quick Check 5 Answer

A community is the set of organisms that live in a given place. A community together with the physical environment in which the organisms live constitutes an ecosystem.