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.
A community in... The main difference between a community and an ecosystem is that the ecosystem is defined as the result of what happens when a community of living organisms shares and interacts within their environment. What this means is that the ecosystem is a product of a specific community.