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树木在幼年时,疏伐是培养母树树冠和提高结实量的一种措施。为此,就疏伐强度对树冠发育的影响问题,进行了研究。在基洛夫省的维亚特—波尔提、马尔梅日和乌尔姑母林管区,设置30块母树林。树龄为8—22年,Ⅱ地位级。林內有300—5,000株树木。在每块母树林內测50栋树木的冠幅。测量结果用统计学和离差分析法整理。为便于整理,将母树林按年龄、密度、冠幅分组。年龄组:8—12年(平均10年),13—17年(平均15年)和18—22年(平均20年);密度组:每公顷1,001—5,000株(平均3,000株),每公顷600—1,000株(平均800株),每公顷300—500栋(平均400株);冠幅组:第一年龄组平均为1.9米,第二年龄组平均为2.2米,第三年龄组平均为4.9米。
When young trees, thinning is to cultivate the tree canopy and improve the yield of a measure. Therefore, the effect of thinning intensity on crown development was studied. In the Kirov province of Vyat - Bolti, Malmö, and U Seoul Forest District, set up 30 mother trees. Tree age of 8-22 years, Ⅱ status level. There are 300-5,000 trees in the forest. The crown width of 50 trees was measured within each parental forest. The results of the measurement were statistically analyzed by dispersion analysis. For ease of sorting, parent trees will be grouped by age, density and crown. Age group: 8-12 years (average 10 years), 13-17 years (average 15 years) and 18-22 years (average 20 years); density group: 1,001-5,000 plants per hectare (average 3,000 plants) per hectare 600-1,000 plants (average 800 plants), 300-500 plants per hectare (average 400 plants). In the coronary artery group, the average age was 1.9 meters in the first age group and 2.2 meters in the second age group. The average in the third age group was 4.9 meters.