论文部分内容阅读
我场一九七六年冬季,采伐了刺槐实生纯林25亩。林令21年,林分的平均树高10.5米,平均胸径13.5厘米,每亩80株,每亩蓄积5.916立方米。属沙石山、沟旁、半阳坡,沙壤土,土层深度25～30厘米,pH值6.1～6.5,坡度22—25°,海拔380～450米,立地条件一般。 一九七七年春季,进行了刺槐萌芽更新,当年平均高生长3.65米,平均胸径2.77厘米,其中树高4.50米以上的新株占37.5％。一九七八年七月下旬调查,平均树高4.92米,平均胸径3.95厘米,其中树高5.10米以上的新株占41％。总之,幼林生长良好。我们的初步做法是:
My field in the winter of 1976, harvesting 25 acres of pure black locust tree. Lin 21 years, the average stand height of 10.5 m, an average diameter of 13.5 cm, 80 per acre, an area of 5.916 cubic meters per acre. Sandy Hill, ditch, semi-sunny slope, sandy loam, soil depth of 25 to 30 cm, pH 6.1 to 6.5, slope 22-25 °, elevation 380 to 450 meters, site conditions in general. In the spring of 1977, the regeneration of black locusts was carried out. The average annual growth was 3.65 meters and the average diameter at breast height was 2.77 centimeters. Among them, 37.5% of the new strains were trees with a height of 4.50 meters or more. In late July, 1978, the average tree height was 4.92 meters with an average breast diameter of 3.95 cm, of which 41% were new plants with a height of 5.10 meters or more. In short, young forest grows well. Our initial approach is: