ecotones

An ecotone is a transition zone between two or more distinct ecological communities or ecosystems. It is characterized by a gradient of environmental conditions and a corresponding change in species composition that occurs over space or time. Ecotones can be abrupt boundaries or broad, diffuse zones where characteristics of both adjacent communities mix gradually.

Ecotones often harbor a mixture of species from the neighboring communities and may host unique assemblages restricted to the transition zone. They can exhibit higher beta diversity and may influence ecological processes such as competition, predation, pollination, and dispersal due to edge effects. Factors such as light, temperature, moisture, soil properties, and disturbance regimes contribute to the distinctive conditions of ecotones.

Formation and examples: Ecotones arise from differences in moisture, nutrients, topography, disturbance, and historical land use. Classic examples include forest–grassland boundaries, wetland–upland margins, riverine edges, and coastal or estuarine interfaces. In aquatic systems, shoreline, riparian, and estuarine zones function as ecotones, linking terrestrial and aquatic communities.

Ecological and conservation relevance: Ecotones increase habitat heterogeneity and can support diverse communities and ecosystem services. They are often sensitive to climate change and human disturbance, causing shifts in their position or structure. Conservation and restoration efforts frequently consider ecotones to maintain connectivity, sustain transitional habitats, and preserve processes that rely on edge dynamics.

Methods and study: Researchers study ecotones by sampling along environmental gradients, using remote sensing to map transitions, and analyzing patterns of species turnover and functional diversity to understand how communities change across the boundary.