If you appraise something or someone, you consider them carefully and form an opinion about them. [formal] This prompted many employers to appraise their selection and recruitment policies. [VERB noun] Gloria slid an appraising eye over the rest of the rack before reaching for the dress.
(a) Natural ecosystem boundaries occur between a tropical evergreen and riparian forest, and between the riparian forest and the river that it borders. (b) Natural boundaries occur across the gradient from marine to intertidal to foreshore environments near the shore in temperate coastal regions.
Scales of Ecosystems Ecosystems come in indefinite sizes. It can exist in a small area such as underneath a rock, a decaying tree-trunk, or a pond in your village, or it can exist in large forms such as an entire rain forest. Technically, the Earth can be called a huge ecosystem.