The northern Cape Breton ecosystem is even more sensitive to change than an ecosystem on the mainland would be because it is part of an island.

Islands within islands

Cape Breton is an island, which means it covers a fairly small land base. Because is surrounded by water, it is relatively difficult to access. The small size and limited accessibility of the island results in small, isolated populations of plants and animals. Because of the rough terrain, certain habitats are broken up even more, creating islands of habitat within the geographic island of Cape Breton.

Smaller islands (both geographic islands and habitat islands) tend to have fewer native species of animals and plants than larger ones - a smaller biodiversity. Smaller biodiversity makes an ecosystem more susceptible to damage because it is less resilient to change.

Populations of plants and animals in small islands face special challenges:

• The populations are generally small and genetically isolated from other populations of the same species. Some individuals in a species might have genes which make them better able to adapt to certain changes - so, if a change occurs and kills most of the population, there might still be some which survive to reproduce. Smaller populations are less likely to have many different kinds of genes, so there is a smaller chance that some individuals will survive environmental change or disease and keep the population going.
• The populations are more susceptible to impacts caused by exploitation of natural resources, global climate change and non-native species.
• Because of the first two challenges, the populations are more susceptible to extinction.

What sorts of changes do we cause?

Often the results of modern human activities, ecosystem stressors are events or actions that cause changes to the driving forces of an ecosystem that maintain biodiversity. They are like health problems for an ecosystem and they can be different for each ecosystem. The northern Cape Breton ecosystem is affected by six major ecosystem stressors:

• Habitat loss and fragmentation
• Presence of non-native species
• Absence of native species
• Tourism impacts
• Pollution
• Global climate change

By understanding the sorts of ecosystem stressors that are affecting our ecosystem, we can figure out what aspects of the ecosystem might be all right for us to change, the changes it can handle, and the changes it cannot.