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.
Learn what an ecosystem is, how energy and matter move through ecosystems, and what makes an ecosystem stable. An ecosystem consists of a community of organisms together with their physical environment. Ecosystems can be of different sizes and can be marine, aquatic, or terrestrial. Broad categories of terrestrial ecosystems are called biomes. In ecosystems, both matter and energy are conserved.