Silviculture

From Wikipedia, the free encyclopedia

Silviculture is the art and science of controlling the establishment, growth, composition, health, and quality of forests to meet diverse needs and values of landowners and society on a sustainable basis.

Contents 1 Regeneration 2 Common Silvicultural Regeneration Methods 2.1 Clearcut 2.2 Seed tree 2.3 Shelterwood 2.4 Selection 3 Thinning 3.1 Methods of Thinning 4 Pruning 5 Other Silvicultural Approaches 5.1 Ecological Thinning 6 See also 7 References

[edit] Regeneration

Forest regeneration refers to the establishment of seedlings following a natural disturbance or a prescribed management activity. Establishment can be either natural or artificial. Natural establishment occurs through newly germinating seeds or resprouting of cut stems. Artificial establishment involves planting of tree seedlings or seeds.

[edit] Common Silvicultural Regeneration Methods

[edit] Clearcut

The removal of all trees in a single cut with the goal of establishing new forest reproduction from artificial or natural means.

[edit] Seed tree

The removal of most trees in a single cut with a few being retained to provide a source of seed for the natural regeneration of the forest. Generally, these retained seed trees are removed following the establishment of the new forest.

[edit] Shelterwood

The removal of trees in a series of cuts to establish new forest reproduction under the shelter of the retained seed trees. The main difference between the shelterwood and seed tree methods is that the residual trees in a shelterwood alter the environmental conditions, such as sunlight, temperature, and moisture, for tree seedling growth, while the few retained trees in a seed tree method do not. Commonly the shelterwood method involves three cuts:

• Preparatory cut
• Establishment cut
• Removal cut

[edit] Selection

The removal of scattered individual trees or groups of trees with the goal of creating and maintaining an uneven-aged forest structure.

[edit] Thinning

The goal of thinning is to control the density, composition, and quality of tree stands and to improve tree growth, especially of the diameter, by providing additional growing space for the remaining trees. It also provides an opportunity to cull the commercially less desirable, usually smaller and malformed, trees.

[edit] Methods of Thinning

• Low Thinning (thinning from below or German thinning)
• Crown Thinning (thinning from above or French method)
• Selection Thinning (thinning of dominants or Borggreve method)
• Mechanical Thinning (row thinning or geometric thinning)
• Free Thinning

[edit] 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 lead to many forestry companies reconsidering their pruning practices.

[edit] Other Silvicultural Approaches

[edit] Ecological Thinning

Main article: Ecological thinning

A contemporary type of silviculture that aims to improve habitat values over time by reducing tree stems through appropriate selection.

[edit] See also

• Forestry
• Plantations
• Ecological Thinning
• Selection cutting
• Hardwood Timber Production

[edit] References

• Daniel, T. W., J. A. Helms, and F. S. Baker 1979. Principles of Silviculture, Second Edition. McGraw-Hill, New York. 521 p. ISBN 0-07-015297-7
• Evans, J. 1984. Silviculture of Broadleaved Woodland. Forestry Commission Bulletin 62. HMSO. London. 232 p. ISBN 0-11-710154-0
• Hart, C. 1995. Alternative Silvicultural Systems to Clear Cutting in Britain: A Review. Forestry Commission Bulletin 115. HMSO. London. 93 p. ISBN 0-11-710334-9
• Nyland, R. D. 1996. Silviculture, Concepts and Applications. The McGraw-Hill Companies, Inc. New York. 633 p. ISBN 0-07-056999-1
• Nyland, R. D. 2002 Silviculture: Concepts and Applications, Second Edition. The McGraw-Hill Companies, Inc. New York. 704 p. ISBN 0-07-366190-2
• Savill, P., Evans, J., Auclair, D., Falck, J. 1997. Plantation Silviculture in Europe. Oxford University Press, Oxford. 297 p. ISBN 0-19-854909-1
• Smith, D. M. 1986. The Practice of Silviculture, 8th edition. John Wiley & Sons, Inc., New York. 527 p. ISBN 0-471-80020-1
• Smith, D. M., B. C. Larson, M. J. Kelty, P. M. S. Ashton. 1997. The Practice of Silviculture, Applied Forest Ecology, 9th edition. John Wiley & Sons, New York. 560 p. ISBN 0-471-10941-X