黄土高原人工植被与其水分环境相互作用关系研究

Interaction Between Soil Water Conditions and Different Kinds of Artificial Plant Cover in the Loess Plateau

以黄土高原半湿润区为代表，就主要人工植被对土壤水分影响现状及其原因，分别立地条件类型，进行了广泛调查与定点测定．结果表明，各种人工植被均有导致深层土壤干化的可能．干化层的出现，是人为高密度粗放经营，造成了水分长期亏损的累积结果．它的存在已对林木的生长及林分的稳定构成了威胁．经对残塬沟壑区人工林地水分年际变化规律进行定位观测，以及对该区土壤、气候特点的分析，认为由于特殊的自然条件，该区森林植被难以发挥涵养水源的生态功能．

For studying the interaction relationships between main kinds of artificial vegetation cover and their soil conditions,a lot of permanent plots were set up, based on main kinds of site types in a large area in the Loess Plateau of China. The results show as follows:1) There is a possibility that the deep layer soil drought can be led by all kinds of artificial vegetation covers. The soil dry layer is the consequence of the long time loss of soil water with high density of crops and extensive management.The soil dry lager now acts as a great effect on growth and stability of forest stands;2) The forests are difficult to give full play to its head water conservation function in the hill and gully region in the Loess Plateau,according to the investigation on the annldal variation of soil water under plantations.