ABSTRACT
Forests have existed on Earth for 350 million years; they reached a peak about 270 million to 220 million years ago during the Carboniferous period (Burch et al., 1976). Today, forests cover about one-third of the Earth’s land surface. They are the most distinguished type of vegetation community and provide many resources and environmental functions that far exceed those of other vegetation covers. Accordingly, forests have always played a vital role in the survival, development, and growth of human society since prehistoric times. Maintaining healthy forests helps improve environmental quality.
