Laserfiche WebLink
<br />OO[}7tJ? <br /> <br />the drier, warmer climate of the mixed conifer <br />forests, more of the response frum altering the <br />cover is altribuled 10 reduction in transpiration <br />and I(!ss to redistribution of snow. hlcreases in <br />water yield oCl to -I inches are p(lssihll~ from dear. <br />cUlling (Rich and Thompson 1974). However. <br />wilhoul type conversion to an herbaceous cover, <br />the increases would decline as the forest regrows. <br />The overall estimate is 1.5 inches average inr.rease <br />from maintaining about one-Ihird of the area in <br />small openings on sitlls where slreamnow nor- <br />mally averages -I to 5 inches (fig. 12). <br /> <br />Rocky ~Iounlain Aspen FOfPSts <br /> <br />Quaking aSpt'O (fig. 13}m;cupies approximately <br />3.3 million acres in the Colorado River Basin. <br />nearly all uf it in the Colorado and Utah portions of <br />the Upper Basin. RouRhly 75% is nn National <br />Forest land. The aspen type is reco}lnized for its <br />multiple \'alues of wood, livestock forage, wildlife <br />habitat. watershed protection, recreation, and <br />esthetics. Aspen is commonly found between <br />7 ,OUO and 10,000 feet t'levation in clumps to exten- <br />sive stands interspersed among conifers of the sub- <br />alpine, mixed conifer, and coolt!r portions of the <br />ponderosa pine type. Precipitation a\'erages 20 to <br />40 inches, one-half or mort! of it snow. Water yitdd <br /> <br />avera~ws 3 to 5 inches in the Lower F.lasin. but may <br />reach 20 inches in the Upper Basin. <br />The potential is good for increasing water yield <br />in the aspen by type conversion, but relatively low <br />from cutting or other practict~s when the objective <br />is aspen stand regeneration. Increases up to 5 <br />inches arc possible frum clearcutting aspen IDe. <br />Byle 1976), but these increases decline rapidly and <br />are gone within 10 to 15 years (fig. HJ, if this <br />prolifically sprouting species is allowed to reco\'er <br />the site, Therefore, if dearculling or other removal <br />practices were to be repealed e\'f'ry flU years, as <br />might be done for timber harvest with stand re- <br />generation. the a\'erage annual illcrt!ase over 80 <br />years would he about olw.third inch O\'er tht! area <br />actually treated. More frequent treatment has been <br />suggested to tmhance browse production for deer <br />and elk and domestic animals (Patton ilnd Jones <br />1977). If c1earcutting or other methods of stand <br />remm'al were practiced 011 d 25-year rotation. for <br />example, increases i1\'eraging about 1 inch per Yf!ilt <br />would be possible on the area i1clually treated. <br /> <br />Southwestern J'onderosa Pine Furests <br /> <br />Ponderosa pille (fiR. 15J occupies about 1.5 <br />million aereS in the Upper Basin and ahout fi mil- <br />lion acres in the Lower Basin. About 70% is on <br /> <br /> <br />Figure 1J.-Queldng upen Is widespread In the Colorado Ri'ol8r Basin. ....ilh more than 90% 01 <br />lhe 3.3 million Icrn loclted in ....eSI.rn Colorado and .aSlern Ulah. <br /> <br />11 <br />