Habitat Fragmentation

Habitats provide vital resources—such as food, shelter, and mates—that support an organism’s survival. A dense, continuous forest habitat, for example, hosts a sizable and diverse wildlife population. However, natural forces and human activity can change a habitat and impact the resident organisms.

Habitat fragmentation is the process by which a formerly continuous habitat is divided into smaller, isolated areas. 

A road cutting through a forest, for example, creates habitat discontinuity that may impede access to key resources for animals. 

Additional human activities, like the clearcutting of trees, can further fragment the habitat. Organisms that cannot relocate to another suitable habitat go extinct. Meanwhile, surviving organisms are at increased risk of extinction because the smaller, fragmented populations have less genetic diversity.

Natural forces also cause habitat fragmentation.

River fluctuations, for example, impact both terrestrial and aquatic wildlife. River flooding may block the passage of terrestrial animals. If the river dries up, migratory aquatic animals may lose their passageway between water bodies.

Habitat fragmentation results in population isolation, habitat loss, and biodiversity reduction.

Edge effects are another common consequence of habitat fragmentation. Edge effects are changes that occur at transitional regions between habitats. For instance, a forest edge abutting an agricultural field is more prone to fires. The increased light exposure dries out the forest vegetation, increasing the chances of a fire.

Since human activity is the primary cause of habitat fragmentation, it is important to mitigate its effects. Wildlife crossings, for example, create corridors for wildlife to safely cross human-made habitat barriers, like roads. Reconnecting fragmented habitats is one of many conservation approaches in use today.