Agents of Change

Agents of change in Alberta's forest ecosystems can originate from natural sources, as well as human activities. Some years, the overall area affected by forest fires, insects and disease is extensive. But these natural processes, active in virtually all of Alberta's forests, are natural agents of change for forest ecosystems. Forest size, shape, distribution pattern and mix of tree species are all affected over time by a combination of climate, landform, and the frequency of fire and other disturbances.

Timber harvesting can also disturb forest ecosystems. As with fire, the changes can be abrupt. Harvesting's potential effects include habitat alteration and fragmentation, a reduction in biological diversity, and soil compaction and erosion. Overall, timber harvesting, fire suppression, and related forest management activities affect the forest ecosystem. In some areas of the province, however, clearing for agriculture and petroleum exploration and development are more significant human disturbances than timber harvesting.

Department of the Environment. State of the Environment Report, Terrestrial Ecosystems. Edmonton: n.p., 2001. With permission from Alberta Environment.