all the plant life in a particular region or period

all the animal life in a particular region or period

the type of environment in which an organism or group normally lives or occurs

the process of adapting to something (such as environmental conditions)

the weather in some location averaged over some long period of time

a plant having foliage that persists and remains green throughout the year

(of a tree or shrub) shedding its leaves annually.

an area, as a prairie, in which the natural vegetation consists

noun one of the vast, nearly level, treeless plains of the arctic regions of Europe, Asia, and North America.