Description - What are the Details?

The adaptive cycle is a conceptual model that can help us understand the structure and processes of complex system dynamics over time (Holling 1992, Gunderson et al. 1995, Carpenter et al. 2001). It consists of four “phases” where the system acts in a distinct way to either structure, collapse, or reorganize itself. Some helpful examples to illustrate this 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.

The adaptive cycle illustrates how systems can, after collapse, reorganize into a system with either similar or different structures and processes. The four phases of the adaptive cycle are the “r” (exploitation or growth) phase, the “K” (energy conservation) phase, the “Ω” (release or collapse) phase, and the “α” (reorganization) phase. They are typically illustrated by a lazy-eight figure (Fig. 1). Please see the “Adaptive Cycle” module for more in depth information on each of these phases and the application of the adaptive cycle itself in management.

However, the adaptive cycle does not stand alone in practice. Every adaptive cycle, and the system that it describes, is linked to cycles above and below the cycle in scale (Figure 3). These scales include both space and time. For example, an adaptive cycle that describes the cyclical nature of a forest that goes through periods of growth, prolonged stability, collapse through fire, and reorganization is then linked to the cycles above and below the forest scale in space. These include smaller patches of forest that may be of one particular species and the surrounding landscape beyond the forest that may include grasslands or even human habitations. Even the examples above, of the collapse of ancient cities, are linked to adaptive cycles in the scales above and below the cities including particular market sectors and the overall climatology of a region. This is panarchy.

Federal governments also illustrate panarchy theory. In a country with a federal system, the national government does not hold all of the power, but instead shares it with regional and/or local governments. As a result, small-scale local governments such as counties and cities may make decisions which aggregate to influence nationwide policy. The large-scale national government also makes decisions which in turn may affect local governments. In the middle may be a regional scale such as states and provinces, whose decisions travel down to affect local scales or travel up to affect national ones.

Panarchy theory has important implications for ecological resilience, because it shows the adaptive cycle does not occur in isolation. The connections among different systems undergoing the adaptive cycle means the resilience of one system is influenced by the systems it is connected to. Panarchies themselves, featuring multiple systems, are not static but instead change as system processes and structures at different scales in the panarchy move through the adaptive cycle (Holling et al. 2002). This change can come about through two pathways. The first is when one scale enters the omega (“Ω”, release or collapse) phase and collapses. In essence, the system components can no longer interact with each other the way they did before. The collapse causes the larger, slower scale or scales above it to experience a crisis. The second pathway is when a system undergoes a collapse and larger and slower scales above it influence how that system reorganizes

Revolt is the first pathway for change as fast and small events accumulate and overwhelm large and slow ones (Holling et al. 2002). Essentially, processes and structures at lower scales overthrow those at higher scales, which may lead to new processes and structures at those higher scales. Higher scales are particularly vulnerable if they are at the “K” (energy conservation) phase, which is more rigid, less adaptable, and less resilient than other phases. An example of revolt is a social revolution, when groups of individuals organizing at smaller scales overwhelm and change a larger scale, such as a national policy or even the governance system of an entire country. An ecology example would be the introduction of one or more invasive species that may live out their lives on a smaller scale, but the disruption to established processes may affect the functioning of an entire ecosystem.

Remember is the second potential pathway within a panarchy. When a scale enters the omega phase and collapses, instead of a revolt, the renewal phase of the scale organizes according to the structure and processes of the larger and slower scale above it (Holling et al. 2002). The higher scale retains institutional memory of the previous structures and processes, and the lower scale uses that memory to create a similar system to what existed at that same scale in the past. An example for remember is a patch in a large forest that has recently burned. The surrounding unburned forest exhibits pressure on the burned patch to return to the prior state as forest species re-enter and re-organize the patch. In practice, this “pressure” that the unburned forest is exhibiting can be as simple as the presence of seeds of the same species of tree that lead the newly burned patch to “reorganize” or regrow as a forest similar in species composition to the surrounding larger scale forest. Both revolt and remember can be seen in Figure 4 as the arrows that connect adaptive cycles at different scales within the panarchy.