Key Components and Variables for Analyzing Human Ecosystems

This chapter draws on lessons learned from prior application of the HEM and includes those lessons in a modest revision of the early work. It details each component and variable by providing a general definition and description, suggesting ways that the variable can be measured, and giving selected examples of how a variable may influence other variables of the human ecosystem. The passage of time and the application of the model in many situations have left most of those early components and variables intact, with only a few key additions and deletions. The chapter aims to provide the HEM user with an integrated set of social, economic, and ecological measures that can be collected over time.