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采用裂区设计连续实施2次人工修枝,研究了不同修枝强度(不修枝、轻度修枝(修去活枝冠层的1/4下层枝条)、中度修枝(修去活枝冠层的1/3下层枝条)、重度修枝(修去活枝冠层的1/2下层枝条)对尾巨桉生长及光合生理的影响。结果表明:修枝强度对胸径、树高和单株材积均无显著影响,其中主区重度修枝的胸径与不修枝基本一样,二者大于轻度修枝和中度修枝;树高基本一样;单株材积变化趋势与胸径变化趋势一致。第1次修枝以重度修枝对生长的促进作用最大,先后2次修枝互作效应较好的是重度修枝-重度修枝、重度修枝-不修枝和不修枝-不修枝3个组合。4种不同修枝强度的净光合速率变化与生长变化趋势一致,主要受瞬时羧化效率影响;蒸腾速率不随修枝强度改变而变化;水分利用效率变化与生长变化趋势一致,其差异主要由净光合速率引起。综合考虑尾巨桉的水分利用效率、生长量最大化和可获得无节材长度3个因素,认为先后2次实施重度修枝-重度修枝是最好的修枝方式。
The split pruning design was used to carry out two consecutive artificial pruning experiments to study the effects of different pruning intensities (no pruning, mild pruning (1/4 lower branches of live branches), moderate pruning The results showed that the pruning intensity had a significant effect on the diameter at breast height and the height at the tree height And the volume of single plant had no significant effect. The DBH of the heavy pruning in the main area was basically the same as that of the non-pruning, both of them were greater than the mild pruning and moderate pruning; the height of the tree was basically the same; The same trend.The first pruning with severe pruning had the greatest effect on the growth, and the second pruning effect was better than the second pruning - severe pruning, severe pruning - no pruning and no pruning - no pruning 3 combinations.The net photosynthetic rate changes of 4 different pruning intensities were consistent with the growth trend, which was mainly affected by the instantaneous carboxylation efficiency; the transpiration rate did not change with the pruning intensity; the water use efficiency and the growth change The trend is the same, the difference is mainly caused by the net photosynthesis rate.Considering the water content of Eucalyptus urophylla With efficiency, and to maximize the amount of growth obtained clear wood length three factors, that has 2 embodiment severe pruning - severe pruning pruning is the best way.