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<br />0006H <br /> <br />. <br /> <br />. <br /> <br />studied. The cl lmatological paramet~rs such as surface winds, maximum snow <br /> <br />deposition, precipitation, and seasonal percolation were related to distance <br /> <br />downwind from the west edge of the forest by sets of linear models. On the north, <br /> <br />substantial increaseS in each parameter generally occurred as the distance lncreased. <br /> <br />On the south the same response was seen to occur as far as surface wind was <br /> <br />concerned. However, maximum snow deposition, seasonal precipitation, an~ seasonal <br /> <br />percolation increased only for short dlstanc~s, usually from one to two tree <br /> <br />heights and then diminished ra~ldly. <br /> <br />From this study it can be readily seen that the observed phenomenon as a <br /> <br />result of the study indicated that the location of the clearcutting was a very <br /> <br />important aspect as far as some of the cl imatologlcal factors are concerned. <br /> <br />The Increases on the south side were not as ?revalent as on the north side <br /> <br />because the Interception of snow on the north side was higher than on the south <br /> <br />side and apparently the snow would stay on the leaves and branches for a longer <br /> <br />, <br />! <br />, <br />, <br />I <br />I <br />I <br />'j <br />, <br />I <br />I <br /> <br />period of time than on the south side. As a result, when the clearings took <br /> <br />place the snow would be allowed to accumulate on the slopes and the larger or <br /> <br />higher snow pack would accumulate: therefore the runoff would be larger on that <br /> <br />side. <br /> <br />There was not much difference in tho snowmelt rate between the north <br /> <br />and the south sIdes. The sprIng snowmelt rates were accelerated after clear <br /> <br />cutting on the north and south sIdes by 45 percent and 44 percent, respectively. <br /> <br />(9) Changes:.ln Streamflow F:>llowlng Timber Harvest In Southwestern Oregon. Forest <br />Service Paper PNW-49, 1979. <br /> <br />Changes In streamflow after complete clearcutting. small patch clearcutling, <br /> <br />and shel terwood cult jng were determined for three small I.atersheds In southwestern <br />and <br />- Oregon. The first increase in annual yield was 39 percent,' the increase averaged <br /> <br />43 percent for the five years on a watershed that was completely clearcut. Increases <br /> <br />average~ 8 to 14 percent in other logged watersheds. <br /> <br />The largest ausolute increase~ <br /> <br />occurred in winter, whereas the largest relative increases genorally occ;rred during the <br /> <br />following ~ummer. The~ maximum differences in soi1~rr.oi5ture cont~r.t generally <br /> <br />6 <br />