黄土高原主要造林树种集流面积的确定

Determination of the Areas of Gathering Water for Main Tree Species on the Loess Plateau

采用人工供水的方法,研究了油松、侧柏、刺槐人工幼林林地土壤水分年变化规律。根据土壤水分对林木的有效性,提出了人工林土壤水分的补偿方法及各树种的集流面积。结果表明,在3个树种中,刺槐林地的难效水频率最高,侧柏的最低。初步提出了在黄土高原年降水量500～600mm的地区,20a生油松和侧柏适宜的集流面积分别为10～12m2/株和5～9m2/株,8a生刺槐为12～20m2/株,年降水量400～500mm的地区,油松和侧柏人工林集水面积至少应为12m2/株和9m2/株,刺槐20m2/株。

Annual change characteristics of forest soil water of Pinus tabulaeformis, Platycladus orientalis and Robina pseudoacacia were studied by irrigating. The compensation method of soil water and the areas of gathering water were put forward based on the soil water effectiveness. The result showed that' among three trees' hard-efficient water ratio of R. pseudoacacia was the highest, and P. orientalis was the lowest. When the precipitation was 500～600 mm, the reasonable gathering areas of 20 years P. tabulaeformis and P. orientalis were 10～12 m^2and 5～9 m^2 respectively' 8 years R. pseudoacacia was 12～20 m^2. However, when the precipitation was 400～500 mm, the gathering areas of P. tabuaeformis, P. orientalis and R. pseudoacacia were more than 12 m^2, 9 m^2 and 20 m^2 respectively.