TABLE OF CONTENTS THE IMPORTANCE OF BIODIVERSITY TO CANADA A CONSTANTLY CHANGING ENVIRONMENT HUMAN IMPACTS ON BIODIVERSITY STRATEGIES FOR BIODIVERSITY CONSERVATION BUILDING ON SUCCESS WHAT DO WE MEAN BY BIODIVERSITY? POTENTIAL IMPACT OF BIODIVERSITY LOSS POSITIVE RESPONSES MORE INFORMATION

A CONSTANTLY CHANGING ENVIRONMENT Change in the natural world is not only measured in eons. To understand how we can contribute to the conservation of biodiversity, we first need to understand how the world around us changes as a result of natural processes. This will enable us to distinguish human induced changes from perfectly natural occurrences and to assess how our actions and interventions mesh with these natural cycles. A simplified example can be provided by forest fires which are usually viewed to be highly destructive because they burn commercially valuable timber. From an ecological perspective, though, fire is an agent of renewal. Fires reduce the number of mature trees on a site, create openings in the canopy and provide nutrients to the soil. Vegetation that is adapted to direct sunlight populates the site. As this vegetation matures, it provides shade for other types of vegetation that are less tolerant to sunlight. Eventually, these trees supplant the colonizing vegetation and grow into a mature forest. Over time, some of these trees will die and become susceptible to insects, disease or fire. Then, the forest may burn once again and this process of succession continues. At each stage in the development of the forest different species will be found on the site. And, while one part of the forest is regenerating another may be burning so that forested areas in different parts of the landscape may all be at different stages of succession. Nature has prepared itself for these successional processes, and species and ecosystems have developed methods to enable them to adapt to changing conditions. Assuming no unforeseen events and a sufficient landbase, you could reasonably expect that each species will always be found on the landscape, although they will be found in different places, in different numbers and at different times. But Nature has few strategies for adapting to the interventions of humans. When we drain wetlands to create agricultural lands, fell forests to produce timber or descend in numbers upon a favourite fishing hole, we are stretching the adaptive capabilities of Nature in ways that we are only beginning to understand.