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营造农田防护林的类型、林带结构以及树种配置都要考虑造林密度。造林密度也是提高林带防护效益和经济效益的重要因素。在常规造林条件下,植树过密,林木单株的营养面积小,降低了林木受光量和对养分、水分的吸收,林木生长不良,抗性减弱,如果技术措施再跟不上,就会招致林木的分化和衰败。与此相反,若造林植株过稀,单位面积林木株数过少,林木生长长时间不能郁闭,
The type of afforestation shelterbelts, the structure of the shelterbelt and the allocation of tree species should consider afforestation density. Afforestation density is also an important factor to improve forest protection and economic benefits. Under normal afforestation conditions, tree planting is too dense, and the nutrient area of individual trees is small, which reduces the amount of light received by the trees and the absorption of nutrients and moisture. The tree growth is poor and the resistance is weakened. If the technical measures can not keep up, it will incur Differentiation and decline of trees. In contrast, if the afforestation plant is too thin, the number of trees per unit area is too small, the forest can not grow for a long time canopy,