Old-growth Forest Uncut forest or regenerated forest that has not been seriously disturbed by human activities or natural disaster. Store houses of biodiversity Provides ecological niches for multitude of wildlife species Stand of trees resulting from secondary ecological succession. When trees are removed from an area by humans(clear cutting) or by natural disasters second growth forms Second-growth Forest
Tree farms Uniformly aged trees of one species that are harvested by clear cutting as soon as they become commercially valuable. They are replanted and cut down.
Even-aged management Maintaining trees in a given stand the same age and size Industrial forestry- replaces a biologically diverse old-growth or second-growth forest. Maintaining a variety of tree species in a stand at many ages and sizes to foster natural regeneration. Uneven-aged management
Selective cutting- intermediate- aged or mature trees in an uneven- aged forest are cut singly or in small groups Advantages reduces crowding of trees encourages growth of new trees Allows natural regeneration Maintains uneven-aged stand of trees Shelterwood cutting- removes all mature trees in an area in two or three cuttings over a period of time. Seed-tree cutting- loggers harvest nearly all of a stand’s trees in one cutting but leave a few uniformly distributed seed-producing trees to regenerate the stand. Strip cutting- is clear cutting a strip of trees along the contour of the land, with the corridor narrow enough to allow natural regeneration.
Clear cutting removes all trees from an area in a single cutting
Forests are used for: 1. Housing- to build 2. Medicines- plants have special uses 3. Fireplaces- burning wood Human activity has reduced Earth’s forests by one-fifth
Fig e p. 202
Increased erosion and runoff Habitat fragmentation Pathways for exotic species Accessibility to humans Fig p. 201