1. Ecotone
Ecotone is transitional area between two biomes or diverse ecosystems (where two communities meet & integrate). Examples : between a field and forest, between forest and grassland.
It has some of the characteristics of each bordering biological community.
May contains some organisms which are entirely different from that of adjoining communities.
Sometimes the number of species & population density of some of the species is much greater in this zone than either community, Known as edge effect.
Ecotones also appear where one body of water meets another (e.g., estuaries and lagoons) or at the boundary between the water and the land (e.g., marshes)
Organisms which occur primarily or most abundantly in this zone are known as edge species.
2. Edge Effect
Tendency for increased biodiversity within the ecotone