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贺兰山地处西北荒漠内陆,气候寒冷干燥,年生长期仅有110～130天,年降水量300毫米左右,地形复杂,土层瘠薄。森林资源面积36万亩。“青海云杉”是构成贺兰山森林资源的主要成份,主要分布在海拔2400～3000米之间的阴坡半阴坡,坡度25～35°的土层较薄的地段。面积27.1万亩,占全林区乔木林面积的71.3％,占总蓄积量的75.9％,林相整齐,为天然复层异令林。为了更有效的发挥云杉林的水源涵养效能,在保持它的生态环境和自然演替相对稳定的前提下.
Helan Mountain is located in the hinterland of the northwest desert, cold and dry climate, the annual growth period of only 110 to 130 days, the annual rainfall of about 300 mm, complex terrain, soil infertility. Forest resources area of 36 mu. “Qinghai spruce” constitutes the main component of Helanshan forest resources, mainly distributed in shady and semi-shady slopes between 2400 and 3000 meters above sea level, and thinner sections with slopes between 25 and 35 °. Area of 27.1 hectares, accounting for 71.3% of the total forest area of arborvitae forest, accounting for 75.9% of the total stock volume, neat forest, natural stratified for different forest. In order to exert the water conservation efficiency of spruce forest more effectively, under the premise of keeping its ecological environment and natural succession relatively stable.