Shelterwood Cutting For Natural Regeneration

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A Cooperative Extension Publication Oregon Washington Idaho PNW 99 April 1968 Methods fected by considerations such as soil depth, Shelterwood Cutting drainage, and exposure. For example, spacing between shelterwood may range from The timber usually is removed in two or 30 to 40 feet. Lower rates of stocking may be NATURAL REGENERATION of sec- three cuts. The preparatory cut comes first; required on favorable sites, north slopes, and ond-growth timber is encouraged by second, the seed cut; and third, the removal in northern portions of the Douglas-fir re- partial cutting, leaving certain trees as a seed cut. In some cases, the preparatory cut may gion than on south slopes, frosty flats, or in source and shelter for new and faster growth. be eliminated as unnecessary or impractical. southern Oregon. Several partial timber-harvesting methods are Where the shelterwood stand is heavy, it may Following in old-growth stands, well adapted to second growth. One such be better to divide the final or removal cut slash, debris, and brush are usually piled method is "shelterwood cutting." This sys- into two or three separate operations, spaced away from seed trees and burned to expose tem may be especially valuable on sites diffi- over a period of several years. Since situa- mineral soil for seed . In second- cult to regenerate through artificial seeding, tions vary greatly, the following is merely growth, this practice usually is unnecessary. planting, or other methods. a guide and should be supplemented by If sufficient exposure of mineral soil has not Stands may be clearcut and regenerated by the advice and assistance of a professional been accomplished in logging, however, fur- artificial methods, but this is costly at best. . ther scarification may be necessary at this Woodland owners should take advantage of a time. natural regeneration, where it will accomplish If the seed cut has not been made in a fair the desired results. Preparatory cut to good seed year, baiting for rodent control Shelterwood cutting removes the timber in This is a light cut, resembling a heavy low may be needed. If artificial seeding is antici- several cuts. As cutting advances, it leaves an to remove the weaker trees, to open pated, genetically suited seed should be used, overstory of selected trees, called shelter- up around the selected shelterwood trees. It preferably treated to repel rodents. Fertiliz- , to seed in the openings. When a new allows the residuals to develop full crowns ing seed trees around the drip line (edge of crop of young trees is established, the older and windfirmness before the seed cut. The crown) may encourage a good seed crop. shelterwood is removed, encouraging the new best dominants should be favored as poten- stand to develop. tial shelterwood seed trees. Not more than Removal cut one third of the stocking should be removed, so as not to encourage reproduction, which This is the timely removal of the seed would be lost at the time of seed cutting. trees, usually done when the new stand is at Sites Slash disposal usually is unnecessary follow- least waist high. Careful logging will avoid excessive damage to the young trees. Newly The shelterwood method can be employed ing this cut. Late commercial may on many sites and on varieties other than already have accomplished the purpose of the established stands often are overstocked, in preparatory cut. patches at least, and can "afford" the loss second-growth Douglas-fir. It is possible to from careful logging. If the final removal cut perpetuate mixed stands or to vary their com- is delayed, excessive damage to large saplings position, depending on how the method is Seed cut and small poles can be expected. Disposal of applied. slash from this cut usually is unnecessary or Shelterwood is especially recommended, Five to ten years after the preparatory cut, impractical. however, in many stands of mature second- the seed cutting removes all but the best seed growth, where experience indicates a problem trees. They are full-crowned, windfirm trees in obtaining natural regeneration by other exhibiting superior parent- characteris- Modifications methods. Trees to be left must be stable tics and efficient reproductive growth po- Shelterwood cutting may be applied to enough to withstand and vigorous tential. patches or strips within a stand, instead of to enough to produce the seed needed. Some In addition to serving as a selected seed the entire stand. As reproduction becomes es- trees may be young enough to increase notice- source, the remaining trees provide partial tablished in these areas, the shelterwood cut- ably in growth rate as a result of shelterwood shade during the reproduction period, and the ting can be extended to remaining uncut methods, although this is not the primary stand is more attractive. Stocking of the shel- areas, until the entire stand has become re- purpose. terwood stand may vary widely. It may be af- produced. Advantages It usually eliminates all need of slash disposal and planting. Since shelterwood is a more intensive method than other regeneration methods, it It is well suited to tractor logging. requires more planning, higher layout costs, and greater skill in application. Greater care It is adaptable to either owner operations in logging also is required, especially with or contract logging. the final or removal cut. Furthermore, it is not well suited to steep slopes. It gives an attractive appearance where aesthetic and recreational values are im- In spite of certain disadvantages, shelter- portant. wood has some distinct advantages. Basically, it is a good natural regeneration method be- A program of commercial thinnings has cause:(1)itissilviculturallysuitedto a tendency to produce a stand which can be thrifty, even-aged, second-growth stands; and reproduced by this method. In some cases, as (2) there is a high degree of certainty that with hemlock, advanced regeneration may desirable, adequate, natural reproduction will even make a one-cut shelterwood cutting be obtained if the method is used correctly. possible. Specifically, here are some of its advantages:

Shelterwood cutting provides an abun- dant source of seed of trees well suited to the particular site, from the best trees in the stand, and offering the best chance of per- petuating trees of the same kind and quality.

With anabundantsourceofseed, chances for obtaining at least adequate regen- eration are very good. This in turn provides more seedlings for a natural selection of the strongest trees.

The shelterwood provides an optimum climatic environment for the young trees dur- ing the regeneration period.

No special treatment of the seedbed is This circular was prepared by Robert Bradley, needed, as logging normally willexpose county extension agent for , formerly in Oregon, now in Pierce County, Washington, in enough mineral soil for adequate regener- cooperation with the Pacific Northwest Woodland ation. Publications Committee.

Topography and weather vary within the Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the Oregon State University Co- Douglas-fir region. This may prove the only operative Extension Service, Gene M. Lear, director; the Wash- ington State University Cooperative Extension Service, John P. practicalregenerationmethodforsouth Miller, director; the University of Idaho Agricultural Extension Service, James E. Kraus, director; and the United States Depart- slopes, frosty fiats, and other severe sites. ment of Agriculture, cooperating. 11M(5-5-l)4-68