Habitat loss and fragmentation

Cape Breton is an island that is made up of many different types of habitat. When one type of habitat occurs in widely separated pockets we have an ecological condition called “habitat fragmentation”. Habitat fragmentation is a problem for species which depend on a certain type of habitat and cannot survive in another, because they become trapped in a small area of suitable habitat. They become genetically isolated, which can lead to their extinction.

Habitat fragmentation in northern Cape Breton is caused naturally by the mountainous topography, but is increased when natural habitat is lost due to human activities. For example, the Europeans settled mostly in the Acadian forest region which was more sheltered and had the best agricultural land. As forest was cleared for farming, the total area of natural Acadian forest was reduced. It now only occurs in small patches separated from each other.

Humans continue to fragment habitat in northern Cape Breton. Cape Breton Highlands National Park has added to the fragmentation of the Acadian forest because it has built most of its facilities like roads, offices, campgrounds, beaches and many trails in this habitat. On provincial Crown lands outside of the park, the Boreal forest has been fragmented by logging and hydroelectric facilities. Private land owners also contribute to habitat loss and fragmentation by clearing forest for lawns and gardens.

Habitat fragmentation changes and breaks up the native habitats, and results in making them less able to support native populations of plants and animals. For example, the American marten requires large, undisturbed stands of mature softwood forest to survive. However, there is not much of this habitat left in the northern Cape Breton ecosystem so there are very few martens left. Habitat fragmentation also opens up the ecosystem to invasion by non-native species of plants and animals.