A transitional area between two neighbouring landscapes, ecosystems or habitats. Because an ecotone represents the interface between two diverse biomes, it offers a more varied range of habitats than the adjacent landscapes in terms of food supply and available nutrients, the number of ecological niches, micro-climatic conditions, etc. This results in a high level of geo-ecological and biotic diversity (landscape diversity, biodiversity). Thus, for example, we find a greater variety of bird species in an ecotone between woodland and meadowland than either within the forest proper or in open land. This favourable impact on diversity is termed the edge effect.

[Source: Martin, Christiane; Eiblmeier, Manfred; Kreutzwald, Lothar; Bischof, Nicole (2001): Lexikon der Geowissenschaften. Nord bis Silb. Heidelberg: Spektrum Akademischer Verlag]