Final answer:
Habitat fragmentation is when large, continuous natural habitats are divided into smaller, isolated patches leading to a loss of biodiversity. It contributes to the decline of species by reducing habitat area and quality, disrupting ecosystem processes, and causing genetic isolation of species populations.
Step-by-step explanation:
Habitat fragmentation refers to the breaking apart of a continuous natural habitat into smaller, isolated patches, which poses a significant threat to global biodiversity. This process involves both habitat destruction, such as deforestation, and habitat subdivision. One of the principal causes of biodiversity loss, habitat fragmentation can arise from various human activities, including agriculture, urban development, and construction of roads which interrupts the expanse of natural environments and creates isolated 'islands' of habitable areas within an otherwise altered landscape.
Habitat fragmentation leads to a decrease in habitat area and quality, reducing the overall species richness and altering ecosystem processes. The remaining isolated patches of habitat may be too small to support viable populations of certain species, and the reduced genetic flow between separated groups can result in inbreeding depression and a further decline in genetic diversity. The rate at which species are lost can be influenced by the size of the habitat fragment, with larger fragments maintaining more species, a concept known as the species-area relationship.
Moreover, habitat fragmentation is not a singular event but occurs over an extended period, leading to gradual, yet inevitable, changes in the ecosystem known as species relaxation. As habitats are incrementally destroyed or condensed, species richness within these fragments typically begins to decline, reflecting the long-term effects of such environmental degradation. Sustainable management and conservation efforts are critical to mitigate the impacts of habitat fragmentation.