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Forest Types • Old Growth- have not been disturbed for several hundred years. High species diversity. Large number of dead trees provide nutrients and habitat. The largest stand of old growth forest in the U.S. is in Alaska. 22% of world’s forest. Many species with specialized niches.
Second Growth- result from secondary succession after they are cut. Less diversity and stability. • Tree Plantations- tree farms. Less diversity and stability.
Importance of Forest • Lumber for housing and other products. • Fuel wood. • Pulp for paper. • Medicines.
Prevent erosion and sedimentation. • Reduce flooding. • Influence climate.
Control global warming. • Noise buffer. • Absorb air pollution. • 1 tree- $196,250 in ecological benefits. As lumber- $590
Types of Forest Management • Even-aged- clear cutting results in trees of the same age and size. Can produce quality trees on long rotation.
Uneven-aged- different age and size trees fosters natural regeneration. Selective cutting. Higher diversity. Multiple use.
Impact of roads • Open up access to previously pristine forest allowing logging, mining, hunting, ranching, and general settlement. • Paves the way for fragmentation, destruction and degradation.
Types of Logging • Selective cutting- fewest trees cut, creates gaps no larger than natural tree fall. Less profitable. Least damage.
Shelterwood cutting- all mature trees removed over a 10 year period. Leaves behind a usable forest.
Seed-tree cutting- most trees cut leaving a few behind to reseed the forest. Leaves behind usable habitat. May produce genetically improved forest.
Clear-cutting- all trees removed, most damaging, most profit. Most environmental degradation.
Impact of Fire In many areas fire suppression has proven to be a mistake. When fires do break out they burn much hotter because of overgrowth.
More on fire Natural forest cycles often include regular, low level fires and many species are adapted for it.
Solutions: Sustainable Earth Forestry • Recycle more paper. • Grow timber on long rotation. • Practice selective cutting • Minimize fragmentation.
Using ecologically sound road building and logging techniques. • Practicing stripcutting. • Leaving dead wood behind as habitat.
Other ecosystems in need of protection • Tropical Rain Forest • Rangeland • National Parks • Wilderness