Using Ecological Succession in Restoration

Ecological succession is the sequence of changes that a biotic community passes through before reaching its maximum possible development within the climatic context of the regional landscape. This is usually a self-sustaining condition often referred to as a climax community. Ecological restoration assists an ecosystem along this successional sequence towards a desired future condition, which is usually at, or near, the climax community (Gayton 2001). Damage generally reverts an ecosystem to an earlier successional stage, or shifts it towards another type of climax community.

By understanding the biotic community that your particular site would naturally support, achievable and appropriate restoration goals can be set. The Ministry of Forests' Biogeoclimatic Ecosystem Classification system (see sidebar) is a useful tool in setting restoration targets and understanding succession on many sites. This system's site series descriptions provide lists of appropriate plant species with which a planting program can be developed, in order to kick-start the process of succession on damaged sites.

Climax is a complex process that is not entirely understood. Originally, climax communities were regarded as the end result of a methodical, linear
process. Today we understand that natural succession is sometimes unpredictable, and can follow several paths depending on site conditions. A different climax community may result. It is also important to note that not all ecosystems were at their climax state before European settlement. Natural and anthropogenic disturbances would have produced a mix of successional stages across the pre-contact landscape (Gayton 2001). In general, natural disturbance regimes play an important role in ecosystem development, and makes 'room' for some species not considered part of a 'climax' community. Disturbance regimes may prevent an ecosystem from reaching its climax community (Gayton 2001), and should be taken into consideration when making restoration plans. For example, excessive disturbance caused by over-grazing of grassland sites will prevent the climax grass community from establishing, and any restoration project should ensure that these types of degrading agents are addressed as a first priority.		Biogeoclimatic Ecosystem Classification system The BEC system is an extremely useful tool for describing and managing BC’s ecosystems. Every BC restorationist should be familiar with how his or her site fits into this classification scheme. For a more complete description please see the Resources Section.

The complexity of ecological succession should not be a barrier to action, but it should encourage restorationists to do their ecological homework before launching into a project (Gayton 2001).

Dave Polster
Succession from bare ground (left) to mature forest (right) is an important natural process that is fundamental to ecological restoration. Re-establishment of natural successional trends is often a goal of restoration projects.