"Microclimates" are created within forests. A valley bottom
collects water and cold air, mountain habitats will be drier on
one slope than the other because of the rainshadow effect, and
south-facing slopes in northern temperate zones are warmer on
average than those facing north. These microclimates affect only
relatively small areas within one type of forest. A valley
creates a microclimate, collecting water and cool air. Photo
courtesy Al Walters.  The forest affects the overall climate,
plus the microclimates. The tree canopy softens the fall of
precipitation hitting the forest floor, protecting smaller
plants from being crushed under the weight of a heavy snowfall.
Water vapor evaporates from trees' leaves, contributing to
moisture levels in the area. Shade from the tree cover helps
keep snow from melting too quickly and causing spring floods.
Forests keep soil temperatures cooler and create shelter from
wind. Without this impact the forest has on the climate, many
species could not persist.  climate --