. Results of shelterwood harvesting of Douglas-fir in the Cascades of western Oregon. Douglas fir Oregon Harvesting; Forest thinning Oregon; Reforestation Oregon; Douglas fir Cascade Range Harvesting; Reforestation Cascade Range. My ocular estimates of overstory shade were a little more closely- correlated with stocking percent of Douglas-fir seedlings (after arcsin transfor- mation of percentages, V = 0. 53 with 11 degrees of freedom) than were my prism estimates of residual basal area per acre. However, analysis and discussion below are based primarily on basal area, since it is much easier
. Results of shelterwood harvesting of Douglas-fir in the Cascades of western Oregon. Douglas fir Oregon Harvesting; Forest thinning Oregon; Reforestation Oregon; Douglas fir Cascade Range Harvesting; Reforestation Cascade Range. My ocular estimates of overstory shade were a little more closely- correlated with stocking percent of Douglas-fir seedlings (after arcsin transfor- mation of percentages, V = 0. 53 with 11 degrees of freedom) than were my prism estimates of residual basal area per acre. However, analysis and discussion below are based primarily on basal area, since it is much easier for foresters to estimate and use. Within limits, the denser the overstory, the greater the percentage of n stocked quadrats for any given seed bed condition (fig. 4). Note that with good site preparation (heavy disturbance), almost any reasonable overstory density will produce satisfactory stocking, I think this result is attributable to the generally mesic conditions prevailing in the localities of these units. Mesic conditions were assumed if adjacent, older clearcuts have generally restocked satisfactorily through planting or have a favorable combination of slope, aspect, and physiographic position. SEED BED. 25 50 75 100 125 150 175 RESIDUAL BASAL AREA (Square feet) Figure 4.—Stocking percent related to residual basal area and kind of seed bed. There are indications that overstory densities above about 50 percent of normal basal area are too dense for satisfactory regeneration. In the Silver Dollar units (units 1 and 2, table 1) the overstories appeared to compete severely with seedlings for soil moisture since seedlings were observed to be much more Percentage data were transformed by arcsin method prior to analysis. The arcsin multiple linear regression equation is: arcsin Y = 147. 1 + 0. 16659 (BAF-10) - 42. 548 (seed bed class). Multiple R = 0. 66** with 1 7 degrees of freedom. Standard error of estimate = degrees. Figure 4 illustrates solutions of this equation
Size: 2384px × 1048px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
