Jaðaráhrif

Jaðaráhrif, or edge effects, describe ecological changes that occur at the boundary between two different ecosystems or land-use types. They arise wherever habitats meet, such as forest and agricultural land, urban interfaces, riversides, or road edges. Conditions at the edge differ from the interior because of increased light, wind exposure, higher daytime temperatures, lower humidity, and different soil moisture and structure. These microclimatic differences influence plant communities and, in turn, the animals that depend on them.

Edge effects can alter biodiversity in multiple ways. Some edge habitats support a greater variety of species due to novel resources and niches, while populations of interior-dwelling species may decline because of competition, predation, desiccation, or habitat loss. Edges can facilitate the movement of organisms and the spread of seeds and diseases, but they can also provide routes for invasive species and pests.

Impacts vary by context and species. For example, certain birds may use edge zones for foraging, while specialist forest interior species may decrease. In vegetation, edge zones can shift communities toward pioneer or weedy species, altering pollination and herbivory dynamics.

Mitigation and management approaches aim to reduce negative edge effects. These include preserving large, contiguous habitat patches, maintaining buffer zones along edges, restoring degraded edges with native vegetation, and creating ecological corridors to connect habitats. Thoughtful landscape planning can minimize abrupt transitions and support more resilient ecosystems.