SFI 2

46問 • 11ヶ月前

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: A treatment designed to free young trees from undesirable, usually overtopping, competing vegetation. Treatments include cleaning, liberation, and weeding (see Stand Improvement).

Release (Release Operation

Trees, pole-sized or larger, retained after the regeneration period under the Clearcutting, Seed Tree, Shelterwood, or Coppice Methods. Synonym: Standards.

reserve trees

The removal of dead trees or trees being damaged or killed by injurious agents other than competition, to recover value that would otherwise be lost.

salvage cutting

The removal of trees to improve stand health and to reduce actual or anticipated spread of insects and disease (see Stand Improvement).

sanitation cutting

A tree, usually young, that is larger than a seedling but smaller than a pole. Size varies by region.

sapling

The art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands. Silviculture entails the manipulation of forest and woodland vegetation in stands and on landscapes to meet the diverse needs and values of landowners and society on a sustainable basis.

silviculture

A planned process whereby a stand is tended, harvested, and re-established. The system name is based on the number of age classes (see Even-Aged, Two-Aged, Uneven- Aged), and/or the regeneration method used (see Clearcutting, Seed Tree, Shelterwood, Selection, Coppice, Coppice with Reserves).

silvicultural system

A classification of site quality, usually expressed in terms of ranges of dominant tree height at a given age or potential mean annual increment at culmination.

site class

A hand or mechanized manipulation of a site designed to enhance the success of regeneration. Treatments may include chopping, discing, bedding, raking, burning, and scarifying. All treatments are designed to modify the soil, litter, vegetation, and to create microclimate conditions conducive to the establishment and growth of desired species.

site preparation

The productive capacity of a site, usually expressed as volume production of a given species.

site quality

Tree sizes recognized by distinct ranges, usually of diameter or height

size classes

A contiguous group of trees sufficiently uniform in age class distribution, composition, and structure, and growing on a site of sufficiently uniform quality, to be a distinguishable unit (see Mixed, Pure, Even-Aged, and Uneven-Aged Stands).

stand

A stand in which there is a mixture of species.

mixed stand

A stand composed of essentially a single species.

pure stand

A stand in which different species occupy different strata of the total crown canopy.

stratified mixture

A quantitative, absolute measure of tree occupancy per unit of land area in such terms as numbers of trees, basal area, or volume.

stand density

A term comprising all intermediate cuttings made to improve the composition, structure, condition, health, and growth of even- or uneven-aged stands.

stand improvement

An indication of growing-space occupancy relative to a pre-established standard. Common indices of stocking are based on percent occupancy, basal area, relative density, and crown competition factor.

stocking

A distinct layer of vegetation within a forest community.

stratum

see Intermediate Treatments.

tending

A cutting made to reduce stand density of trees primarily to improve growth, enhance forest health, or to recover potential mortality.

thinning

The removal of trees from the dominant and codominant crown classes in even-aged stands, or in even-aged groups within uneven-aged stands, in order to favor the best trees of those same crown classes.

crown thinning

The removal of trees in even-aged or uneven-aged stands to control stand spacing and favor desired trees using a combination of thinning criteria without regard to crown position.

free thinning

The removal of trees from the lower crown classes to favor those in the upper crown classes.

low thinning

The thinning of trees in either even- or uneven- aged stands involving removal of trees in rows, strips, or by using fixed spacing intervals.

mechanical thinning

The removal of trees in even-aged stands, or in even-aged groups within uneven-aged stands, in the dominant crown class in order to favor the lower crown classes.

selection thinning

The period of time between successive thinning entries, usually used in connection with even-aged stands (see Cutting Cycle).

thinning interval

The relative capacity of a plant to become established and grow in the shade.

tolerance shade

A stand composed of two distinct age classes that are separated in age by more than 20 percent of rotation.

two-aged stand

The root pruning of seedlings in a nursery bed.

undercutting

A stand of trees of three or more distinct age classes, either intimately mixed or in small groups.

uneven-aged stand

: A planned sequence of treatments designed to maintain and regenerate a stand with three or more age classes (see Single Tree Selection, Group Selection).

uneven-aged system

A release treatment in stands not past the sapling stage that eliminates or suppresses undesirable vegetation regardless of crown position.

weeding

The disturbance of seedling roots in a nursery bed (e.g., with a tractor-drawn blade) with the objective of stimulating the development of a fibrous root system

wrenching

A seed tree method in which some or all of the seed trees are retained after regeneration has become established to attain goals other than regeneration.

seed tree with reserves

A method of regenerating an even-aged stand in which a new age class develops beneath the partially shaded micro-environment provided by the residual trees. The sequence of treatments can include three distinct types of cuttings: (1) an optional preparatory harvest to enhance conditions for seed production; (2) an establishment harvest to prepare the seed bed and to create a new age class; and (3) a removal harvest to release established regeneration from competition with the overwood. Harvesting may be done uniformly throughout the stand (Uniform Shelterwood), in groups or patches (Group Shelterwood), or in strips (Strip Shelterwood).

shelterwood

A variant of the Shelterwood method in which some or all of the shelter trees are retained well beyond the normal period of retention to attain goals other than regeneration. The resulting stand may be two-aged or tend towards an uneven-aged condition as a consequence of both an extended period of regeneration establishment and the retention of reserve trees that may represent one or more age classes.

shelterwood with reserves

Methods designed to maintain and regenerate a stand with two age classes (see Shelterwood with Reserves and Coppice with Reserves).

two-aged methods

Methods of regenerating a forest stand, and maintaining an uneven-aged structure, by removing some trees in all size classes, either singly, in small groups, or in strips.

uneven-aged methods

A method of regenerating uneven-aged stands in which trees are removed, and new age classes are established, in small groups. The maximum width of groups is approximately twice the height of mature trees, with small openings providing micro-environments suitable for tolerant regeneration and the larger openings providing conditions suitable for more intolerant regeneration. In the Group Selection system, the management unit or stand in which regeneration, growth, and yield are regulated consists of a landscape containing an aggregation of groups (see Clearcutting).

group selection

A method of creating new age classes in uneven-aged stands in which individual trees of all size classes are removed more or less uniformly throughout the stand to achieve desired stand structural characteristics.

single tree selection

Methods of regenerating a stand in which the majority of regeneration is from stump sprouts or root suckers.

coppice methods

A method of regenerating a stand in which all trees in the previous stand are harvested and the majority of regeneration is from sprouts or root suckers.

coppice

A coppice method in which reserve trees are retained to attain goals other than regeneration. The method normally creates a two-aged stand.

coppice with reserves

The time between the initial regeneration cutting and the successful re-establishment of a new age class by natural means, planting, or direct seeding.

regeneration period

A stand in which three or more distinct age classes occupy approximately equal areas and provide a balanced distribution of diameter classes.

regular uneven-aged stand

MT 7

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MT 7