The edge of two or more ecosystems. For example, the two
banks of the river, the interface between the woods and an open field,
a hedgerow next to a field of tall grass, the meeting of freshwater
with salt water (i.e., estuary), etc. This zone is a region of high
biodiversity and attracts plants and animals to it that cannot usually
be found in any of the bordering ecosystems. For this reason, alone
the ecotone is a valued (albeit small) piece of real estate.