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以江苏省泗阳农场 8hm2 的试验林为基础 ,评价了修枝强度和修枝季节对I - 69杨人工林生长及萌枝发生数量的影响。该试验采用裂区设计 ,主处理为修枝强度 ,分为 3种水平(1 /3H、1 /2H和CK) ;副处理为修枝季节 ,分 2个水平 (生长季和非生长季 )。研究结果表明 ,修枝处理后当年 ,不同修枝强度的林分叶面积指数存在显著差异 ,中度修枝 (1 /2H)林分的叶面积指数仅为对照处理的 49% ,弱度修枝林分叶面积指数为对照的 84% ;不同修枝季节对杨树人工林的生长影响不显著 ,但对萌枝发生数量影响显著 ,非生长季修枝林分的萌枝发生数量比生长季修枝林分高出 79.8% ;与对照相比 ,修枝处理 4a后 ,其平均胸径和平均单株材积 ,都略有下降 ,但均未达差异显著水平 ;而不同修枝强度的林分枝下高存在显著差异 ,中度修枝林分枝下高可达 6m ,弱度修枝的林分为 4.5m左右 ,而对照处理仅为 2 .0m。
Based on the 8hm2 experimental forest in Siyang Farm of Jiangsu Province, the effects of pruning intensity and pruning season on the growth and the number of sprouting of I - 69 poplar plantations were evaluated. The test was conducted on a split-plot design with main treatments of pruning strength divided into three levels (1 / 3H, 1 / 2H and CK); the secondary treatment was pruning season with 2 levels (growing season and non-growing season) . The results showed that there was a significant difference in the leaf area index of different pruning intensity in the year after pruning. The leaf pruning index of moderate pruning (1 / 2H) forest was only 49% of the control, The leaf area index of branches was 84% of the control. The effects of different pruning season on the growth of poplar plantations were not significant, but the number of branches was significantly affected. The number of shoots in the branches of non-growing season was higher than that of the growth Compared with the control, the mean DBH and the average single plant volume decreased slightly after the pruning treatment for 4 years, but they did not reach the significant difference; however, the forest with different pruning intensity There were significant differences in the height of the branches. The height of the branches was about 6m in the middle of the branches, and the length of the branches in the branches was 4.5m, while the control was only 2.0mm.