黄土高原人工林地土壤水分亏缺研究  

Soil Moisture Deficit in Artificial Forest Land in Loess Plateau

作　　者：易亮[1] 李凯荣[1] 张冠华[1] 牛俊[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨陵712100

出　　处：《西北林学院学报》2009年第5期5-9,49,共6页Journal of Northwest Forestry University

基　　金："十一五"国家科技支撑计划课题(2006BAD03A02)

摘　　要：在对黄土高原林地土壤水分有效性分级的基础上,提出了林地土壤水分亏缺的评价方法与标准。分析和评价黄土高原人工林地土壤水分亏缺变化及其亏缺度,对于调控水分关系,解决水分供需矛盾具有重要的指导意义。结果表明,黄土高原人工林地土壤水分供耗矛盾突出,不同植被地带人工林地水分亏缺度表现为森林带<森林草原带<典型草原带,亏缺度由森林带的不亏缺逐渐增大到典型草原带的61.52%;阴坡水分亏缺度小于阳坡,坡下部小于上部,缓坡小于陡坡;土壤剖面的水分循环活跃层亏缺度要远小于强烈耗水层,最大相差达66.67%;林地土壤水分的动态变化具有明显的季节变化性,雨季时一般供水量大于耗水量,林地水分亏缺程度较轻,但雨季前植被蒸腾耗水较强,水分供需矛盾突出,亏缺程度较重。Scientifically analyzing and evaluating the soil moisture deficit and its deficit degree in artificial forest land in Loess Plateau can provide guidance significance for regulating water relation and solving con tradiction between water demand and supply. Based on the calssification of soil water availability of forest land in Loess Plateau, the evaluation method and criteria of soil moisture deficit were proposed, and a moisture deficit degrees in this area were analyzed. The results showed that there was a significant inconsistency between soil moisture supply and consumption in forest land. Soil moisture deficit in different vegetation zones increased in the order of forest zone 〈 prairie-timber zone 〈 typical steppe zone. The deficit degree increased from 0 for forest zone to 61.52% for typical steppe zone. The degree of moisture deficit in shady slope was lower than sunny slope, bottom of the slope lower than top of the slope and gentle slope lower than steep slope. The whole soil profile also showed a different moisture deficit degrees, the active layer of hydrologic cycle was well lower than intense consumption layer, the maximum difference reached to 66.67%. Soil moisture in forest land also changed seasonally. Water supply quantity was generally higher than water consumption in rainy season, and the water deficit level was milder. However, higher vegetation transpiration before rainy season led to a serious contradiction between water supply and consumption, and the deficit level was stronger.

关 键 词：黄土高原 土壤水分 水分亏缺度 人工林地 

分 类 号：S714.5[农业科学—林学]