Introduction - What Is the Adaptive Cycle?

The adaptive cycle is a conceptual model that helps humans understand the structure and processes of complex system dynamics over time (Carpenter, Walker, Anderies, & Abel, 2001; Gunderson, Light, & Holling, 1995; Holling, 1992). It consists of four “phases” where the system acts in a distinct way to structure, collapse, or reorganize itself. Some helpful examples to illustrate this model include aquatic algal blooms, commodity crop markets, and cities such as ancient Rome, Jerusalem, or San Francisco that were repeatedly attacked or damaged, and then rebuilt. In this module, we mainly use the example of the Roman Empire to illustrate the four phases of the adaptive cycle.

Figure 1. The Adaptive Cycle. Courtesy A. Garmestani, US EPA.

The adaptive cycle illustrates how, after collapse, systems reorganize into either similar or different structures and processes (see Alternative Stable States module). The four phases of the adaptive cycle are the “r” (exploitation or growth) phase, the “K” (energy conservation) phase, the “?” (release or collapse) phase, and the “α” (reorganization) phase. They are typically illustrated by a lazy-eight figure (Fig. 1). In the next section, we will walk through the adaptive cycle phases, using ancient Rome as an example.