Shelterwood Cuttings As Securing the Greatest Possible Con- U
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PULP PAPER PULPWOOD world Shelterwood .:71:1174 cutting ww ,131 ♦tinS .11M SI SLIM ...ant +,..s■, studied to see if young-growth hemlock can be regenerated by series of successive cuttings A report by —Portland, Ore. Forest is owned by St. Regis Paper A STUDY NOW UNDERWAY at the Hem Co. and leased to the U.S. Forest FRANCIS R. HERMAN lock Experimental Forest near Grays Service under a cooperative agree- Pacific Northwest Forest and Harbor in western Washington is de- ment to conduct research aimed at Range Experiment Station signed to test shelterwood cuttings as securing the greatest possible con- U. S. Forest Service a means of regenerating coastal west- tinuous yield. Logging on the experi- Portland, Ore. ern hemlock. Hemlock Experimental mental forest is done by St. Regis and research is conducted by the Pacific Northwest Forest and Range Experi- ment Station, Portland, Ore. In the U.S. Forest Service report, "Timber Resources for Americas Fu- ture," we are told that more than 18% of the national pulpwood output is + tiat# .„, sp kfl #4,1, f4 s 1 ft produced in the Pacific Northwest. To continue to furnish this proportion of FOREST WITH CLOSED CANOPY PRIOR TO CUTTING Americas pulpwood requirements in the year 2000, Pacific Northwest for- ests must produce perhaps as much as three and one-half times the pres- ,A, W ent output. Even so, an estimated na- 4_4 4 a tional demand for 89 million cords of SELECTED TREES RETAINED TO SEED CUTOVER AREA pulpwood may require the United States to import nearly 15 million cords. Successful methods of obtain- ing quick regeneration and maintain- j ing optimum stocking on all forest lands will assist in preventing possible 4 . • ii_fij .1tiiiiiii6.4t .iIiiki,.. eit ift4tA 0,444 i...“41k i_S.S.A11 shortages in wood products. LEAVE TREES AFTER SECOND CUT The wood of western hemlock is admirably suited for producing good pulp and lumber. Many mills in the Pacific Northwest look to hemlock to furnish at least a portion of their *tintittIIIIIIit, it4.tt•.:004r4 41-441431IMI.ItssM131tt.4404:. AIII4t$1#4$14. cordwood and sawlogs. Some mills ESTABLISHED REGENERATION AFTER THIRD CUT in western Washington are currently utilizing hemlock in preference to other species. Western hemlock is SHELTERWOOD MANAGEMENT SYSTEM, showing successive stages of regen- blessed with many attributes that eration in western hemlock forest. make it a good candidate for man- Reprinted from PULP PAPER, June 11, 1962 Purchased by the U.S. Forest Service for official use . shelterwood cutting SEED TRAP makes it possible to estimate amount, viability TRACTOR AND SULKY used for skidding tree-length logs and distribution of hemlock seed for any of several shel- from shelterwood compartment to roadside landing for terwood cutting intensities. bucking into pulpwood or sawlogs. agement. It is a prolific producer of quick and abundant regeneration? shelterwood cutting system seed and, when provided with its Early in this century, logging, for- is being tested on the Hemlock Ex- proper environmental condition, est fires, and windstorms in western perimental Forest, 15 miles north of grows rapidly, tall, and straight. Washington left some scattered old Hoquiam, Wash.—an "experimental hemlock trees and provided environ- island" within a large area of young- Clear cutting of old-growth mental conditions suitable for the es- growth western hemlock. The original hemlock commonly has been accepted tablishment of extensive, even-aged forest was logged near the turn of the as the only method that will provide stands of nearly pure young-growth century, and the bulk of the present conditions conducive to reestablish- hemlock. The exact nature of these stand is now about 60 years old. A ment of hemlock. Is it certain, how- environmental conditions is unknown. few scattered, older western hemlocks ever, that clear-cutting management These older trees provided seed and that escaped the early logging are of young-growth western hemlock will some degree of shelterwood protec- found throughout the area. The stand provide the best conditions for stand tion for the young forest. We cannot averages 270 stems per acre in trees regeneration? Examination of recently turn back the pages of history and 6 to 30 in. in diameter, and volumes cutover young-growth hemlock forest conveniently look in upon acciden- exceed 43,000 bd. ft. per acre. Here land reveals an abundance of weeds tally created growing conditions. on 68 acres in this nearly pure stand and brush but only a sparse cover of However, we can artificially create of young-growth western hemlock, ef- new hemlock seedlings. Would some varied sets of conditions and measure fects of a wide range of shelterwood form of partial cutting, such as the resulting environmental influences cuttings on regeneration are being shelterwood system, prove more suc- conducive to establishment of a new studied. cessful than clear cutting in providing forest Comparison of 12 cutting intensi- RESIDUAL SHELTERWOOD stand after initial cutting has AFTER INITIAL CUTTING this stand has 54 trees per acre. 23 trees per acre. Research will show if this is lighter Second cut in 5 years will leave half these trees to pro- shelterwood stand than is desirable. vide seed and soil protection. ties is being made in residual stands tition from other plant species, light of 20 to 200 trees per acre. Logging intensity, aspect, slope, and seedbed on cutting compartments of from 5 to as well as the factors of seed fall, 7 acres each began in 1960. After in- germinative capacity, and seedling terruption by winter weather, initial survival. cuts on all 12 compartments were In an effort to discover the quantity completed according to prescribed of seed that falls under each intensity plan in the late summer of 1961. of cutting, simple but effective seed Nearly 2,000 cords of pulpwood and traps made of wire screen fitted into 370,000 bd. ft. of sawlogs were re- a wood frame are placed within each moved in this first cut. According to shelterwood-cutting compartment. A the shelterwood management plan, number of these traps scattered over second and third cuttings on all com- a known area give an estimate of the partments at intervals of 5 years will available seed supply per acre. Con- complete the cutting schedule. tents of the traps are collected and examined several times a year. Shelterwood management differs from clear cutting in that it delays Logging costs and returns the time when the forest is completely for the entire shelterwood manage- cut over. Seed-bearing trees are re- ment cutting period are being kept. moved by two or more successive fell- Because work is less concentrated ings instead of by single cutting. Thus under shelterwood than under clear- a new crop establishes itself from the cutting management, logging costs surviving seed trees. As the term sig- may be somewhat higher. Even extra nifies, shelterwood also provides shel- cost may be justified if healthy re- ter or protection. Crowns of retained generation can be obtained more trees shade the forest floor and pro- quickly under one than under an- tect new seedlings from bright sun- other cutting treatment. light and detrimental temperature On other portions of the Hemlock extremes. The limited intensity of sun- Experimental Forest, periodic thin- light also controls the development of nings have been carried out since undesirable brush and weeds that 1950. These thinnings are designed might delay the establishment of a to remove the least desirable mem- young forest. bers of the stand and promote de- Shelterwood cutting permits for- velopment of the better members of esters to select and retain certain the crop. The thinnings are stimulat- trees for their seed-bearing ability ing good crown development that will and growth potential. In addition to produce good seed crops later on. providing an abundant supply of These stands are being groomed for seed, the released trees will increase application of the best management their rate of wood production—both —be it shelterwood or some other re- in quantity and quality. Shortened generation cutting method. rotations, improved yield volumes, It is from thinning experiments that and selected quality all may be ob- we get an inkling of the growth ca- tained through careful shelterwood pacity of young-growth western hem- management. lock. The net mean annual increment Unlike the claims made for many to date has been 158 cu. ft. or 828 health tonic elixirs that purportedly bd. ft. per acre. The experimental for- cure all ailments, shelterwood manage- est is growing rapidly, however, and ment is not said to be perfect. There the thinned stands show a current net undoubtedly will be problems asso- periodic yearly increment of 179 cu. ciated with the application of the ft. or 1,490 bd. ft. per acre. shelterwood system. One of the pur- Time is not far off when young- poses of the study is to evaluate these. growth western hemlock stands will Foremost is the possibility of logging be called upon to bear a major por- damage to established seedlings dur- tion of the rapidly increasing demand ing successive cuttings. Young growth for cellulose. Some of these stands, established after a first cut may be though only 40 to 60 years old, even damaged by felling and skidding in now furnish pulpwood to the ever- subsequent cuts. Amount of damage increasing capacity of pulp and paper sho. 1,1 be associated with the amount mills. Foresters must learn to man- of timber cut each time. The final age this young crop of wood to main- measure of success will be the rela- tain wood growth at least equal to tive abundance of healthy hemlock that of demand.