Silviculture

Silviculture is the practice of controlling the establishment, growth, composition, health, and quality of forests to meet diverse needs and values. The name comes from the Latin silvi- (forest) + culture (as in growing). The study of forests and woods is termed silvology.

Contents

Regeneration

Forest regeneration is the act of renewing tree cover by establishing young trees naturally or artificially, generally promptly after the previous stand or forest has been removed. The method, species, and density are chosen to meet the goal of the landowner. Forest regeneration includes practices such as changes in tree plant density through human-assisted natural regeneration, enrichment planting, reduced grazing of forested savannas, and changes in tree provenances/genetics or tree species. "Human-assisted natural regeneration" means establishment of a forest age class from natural seeding or sprouting after harvesting through selection cutting, shelter (or seed-tree) harvest, soil preparation, or restricting the size of a clear-cut stand to secure natural regeneration from surrounding trees. "Enrichment planting" means increasing the planting density (i.e., the numbers of plants per hectare) in an already growing forest stand."[1]

Common methods

Silvicultural regeneration methods combine both the harvest of the timber on the stand and re-establishment of the forest. The proper practice of sustainable forestry[2] should mitigate the potential negative impacts, but all harvest methods will have some impacts on the land and residual stand.[3] The practice of sustainable forestry limits the impacts such that the values of the forest are maintained in perpetuity. Following are some common methods:

Intermediate stand treatments

Release treatments

Thinning

The goal of thinning is to control the amount and distribution of available growing space. By altering stand density, foresters can influence the growth, quality, and health of residual trees. It also provides an opportunity to capture mortality and cull the commercially less desirable, usually smaller and malformed, trees. Unlike regeneration treatments, thinnings are not intended to establish a new tree crop or create permanent canopy openings.

Common thinning methods:

Ecological thinning is where the primary aim of forest thinning is to increase growth of selected trees, favoring development of wildlife habitat (such as hollows) rather than focusing on increased timber yields. Ecological thinning can be considered a new approach to landscape restoration for some types of eucalypt forests and woodlands in Australia.

Pruning

Pruning, as a silvicultural practice, refers to the removal of the lower branches of the young trees so clear knot-free wood can subsequently grow over the branch stubs. Clear knot-free lumber has a higher value. Pruning has been extensively carried out in the Radiata pine plantations of New Zealand and Chile, however the development of Finger joint technology in the production of lumber and mouldings has led to many forestry companies reconsidering their pruning practices. "Brashing" is an alternative name for the same process.[6]

See also

Citations

  1. ^ 'Fact Sheet 4.12. Forest Regeneration', IPCC Special Report on Land Use, Land-Use Change And Forestry
  2. ^ Oregon State University Extension Service
  3. ^ RESIDUAL DAMAGE IN A CONIFER STAND THINNED WITH A CTL SYSTEM, University of Idaho
  4. ^ Smith, D.M., B.C. Larson, M.J. Kelty, P.M.S. Ashton (1997) The Practice of Silviculture: Applied Forest Ecology, John Wiley & Sons, p. 340-46
  5. ^ Kohm, K. A, and Franklin, J. F., Creating a forestry for the 21st century: the science of ecosystem management. Island Press. 1997, ISBN 9781559633994
  6. ^ The Dictionary of Forestry, The Society of American Foresters

References

External links