What types of old-growth forests are there?
Old-growth forests are virgin and old second growth forests, of approximately 350 years old, which have not been seriously disturbed for several hundred years. They accumulate biomass more efficiently than any other biome and have the world’s largest accumulation of snags and fallen dead trees. These recycle nutrients into the soil over a 200-400 year cycle. They are unusually rich in wildlife for their latitude; hold enough moisture to protect against fires, floods, and to nourish nearby streams; and protect the survival of young salmon by keeping sediment from clogging streams. Sixty percent of tropical rainforests are old-growth forests. Second-growth forests are stands of trees resulting from secondary ecological succession after cutting. About 40% of tropical rainforests are second-growth forests. g05. How are forests of geological importance? g07. How did plate tectonics affect the diversity of ecosystems? m02. Are there other threats to forests? m03. How can the forests, as reso
