Forestry is the discipline embracing the science, art, and practice of creating, managing, using, and conserving forests and associated wildlife, water, and other resources for human benefit and in a sustainable manner to meet desired goals, needs, and values. The broad field of forestry consists of those biological, quantitative, managerial, and social sciences that are applied to forest management and conservation. Forestry includes specialized fields, such as tree nursery management, forest genetics, forest soil science, silviculture (manipulating and tending forest stands), forest economics, forest engineering, and agroforestry (growing trees and food crops on the same land). Industrial forestry is focused on efficient and profitable production of trees for wood or fiber while meeting criteria of water and air quality, wildlife habitat, and esthetic values. In Oregon, Washington, California, and other states there are regulations governing forest management practices. Nonindustrial forestry (or small, private forestry) is practiced by many landowners to provide wood for income, recreational, and esthetic values and, often, a forest retreat from the bustle of urban life. Multiple-use forestry, practiced on many federal lands in the United States, includes considerations of potential wood production, wildlife habitats, recreation opportunities, watershed protection, grazing opportunities for cattle or sheep, and special values such as nests of rare birds or areas of historical or spiritual significance. Wilderness and recreation areas of federal and state forest lands are managed with special considerations for maintaining pristine landscapes and providing opportunities for hiking, camping, boating, and other activities compatible with forests.
Foresters use a broad variety of technical skills, techniques, and equipment to tend, manipulate, and harvest forest trees and to evaluate and maintain water, wildlife habitat, recreation, and scenic values of forests. Foresters measure and evaluate resource values using aerial photographs, satellite images, global positioning systems, laser measuring devices, statistical sampling systems, field computers for data entry, and computer systems for data compilation, calculations, and simulation modeling (e.g., FORTOON, a gaming simulation by J. P. Kimmins of the University of British Columbia and associates). In harvesting trees and planning the next forest, foresters are concerned about tree sizes and the strength qualities of wood, disturbances to the remaining forest that may affect planting new trees, and maintaining water quality and wildlife habitat values. Regenerating a new forest, which may be expected to grow for twenty to one hundred or more years (de-pending on forest type and tree species), often involves planting seedlings, small trees grown in nurseries or greenhouses. These seedlings may be genetically improved, that is, grown from seeds from carefully selected and tended parent trees. New seedlings must often be protected from being eaten by deer, mice, or other forest dwellers, and competing vegetation (like weeds in a garden) must be controlled so the new trees can grow. Where the land is not too hilly or steep, trees can be planted from a plowlike machine pulled behind a tractor. In mountainous areas workers plant trees by hand using special hoes or shovels. In some forests, especially those of pines and other conifers, foresters often thin out some trees after a few years to leave more growing space for desired trees. And, on certain types of soils that are not so fertile, foresters may add fertilizers to improve tree growth (just as one might fertilize a lawn or garden).
Planning and management of forests must include consideration of the following matters:
- What kinds and amounts of wood can be cut, removed, and sold?
- Should all trees be cut (clearcut), only a few high-value trees (selection harvest) be cut, or should most trees be removed, leaving a few for shade and seed for the next forest (shelterwood)?
- What parts of a forest should or must be protected for the common good (e.g., streams and streamside zones; critical wildlife habitats, such as eagle nests; areas of special scenic beauty)?
- What can be kept as trees are cut (e.g., campsites; hiking trails; scenic vistas)?
- Operations planning: for instance, road building, timber harvest and transport, reforestation; forest stand tending (control of competing vegetation; thinning)
- Financial analysis: for instance, assessing where wood can be sold; costs, expenses, and potential profits; reinvestments needed for things such as road maintenance, tree nurseries, and pest controls.
For many state and all federal forest lands, and increasingly for private industrial forests, planning and management activities must involve informing neighbors and others of how the forest, including water, wildlife habitats, and recreation values will be changed. People care about their forests, whether they own them or not.
Forest scientists at universities and industrial, state, and federal research sites are constantly involved in seeking knowledge about how natural forests grow and change and how to grow better trees for human use. Today this research includes genetic engineering research with trees. An example of this is production of a tree that will not be killed by a weed-killing chemical (herbicide) used to control plants competing with desired tree growth. Research continues on basic wood structure and how to get more trees with desired wood strength or whiter paper-making fibers. Foresters and forest scientists are very knowledgeable about many aspects of how forests grow and change. But with increasing replacement of natural forests by managed plantations, and with urban areas expanding to forest edges, more detailed knowledge is needed about how trees use water and nutrients and interact with other plants, animals, and microorganisms in forests. Forest ecologists work in laboratories, large-scale research plots, and experimental forests to provide knowledge for better forest management for all forest products and values.
The forests of the world have many types of trees and wood, from black walnut and cherry of the midwest to spruces of the north, pines of the south and Douglas-firs of the Pacific Northwest to eucalyptus trees of Australia. Forest engineers, wood products engineers, and wood scientists work on new ways of harvesting, transporting, and processing trees to make boards, beams, paper, plywood, and glued-together composite materials with very specific properties (e.g., strength), and other products such as the new fabric tencel. These people extend the work of foresters to our homes and everyday lives.
see also Coniferous Forests; Deciduous Forests; Forester; Rain Forests; Trees; Wood Products.
James R. Boyle