黄土高原荒坡与林地土壤水分变化规律研究

Soil moisture dynamics in forest land and wasteland of Loess Plateau.

为探讨黄土高原有、无林地土壤水分全年变化规律之异同 ,在黄土高原半湿润区 ,采用中子水分测定仪定位测定方法 ,对无林沟坡 (荒坡 )与林地土壤水分储量变化进行了连续 3年的定点测定 .结果表明 ,在 0～3 2 0cm的测定深度内 ,阴坡上、下部与阳坡下部荒坡土壤储水增量分别为 -165 .7mm、-115 .2mm和 -74.9mm ;阴坡上部的油松林地 ,在 0～ 3 2 0cm深度内 ,林地却在林木每年蒸腾消耗大量水分 (达 3 80mm以上 )后 ,增加储水量 17.2mm ,年际收支基本平衡或略有盈余 .林地与荒坡水分收支关系有着本质的差异 .提出了开展林地有效水分获取途径研究的必要性 .

The dynamics of soil moisture stored in a wasteland and in a forest land in the sub humid climate region of the Loess Plateau was measuerd with neutron moisture meter for three successive years.Within the depth of 0～320cm,the increment of soil water in the test 3 years was respectively -165.7mm,-15.2mm and -115.2mm at the upper and lower position on north slopes and the lower position on south slope of the wasteland.Soil water increased by 17.2mm at the upper position on north slope of the Chinese pine forest land, after>380mm water was consumed yearly by tree transpiration.It is suggested that forest land is essentially different from wasteland in soil water income/expense.The necessity of conducting the approaches for gaining available water of forest land was put forward.