摘要
采用沙地土壤定位研究方法,系统地研究了毛乌素沙地土壤的水分特性及SPAC(土壤 植物 大气连续体)中水势的变化规律。结果表明:(1)经验方程θ=AS-B对该地区的土壤水分特征曲线有良好的模拟性,该区土壤的水分特性为:持水量低,供水力小,耐旱性差;(2)水分从树叶扩散到大气中的阻力是土壤 植物 大气连续体中水分传输的主要阻力,土壤水势的变化受降雨、土壤蒸发和林木蒸腾的共同影响,林地的土壤水分表现出明显的季节性变化,树木的叶水势日变化呈明显的单峰曲线,树木受到水分胁迫时水势最低值出现的时间前移,大气水势、土壤水势与叶水势之间均具有一定的相关性。
The sandy soil positioning research method was used to study the soil water characteristics and the variation of water potential in SPAC were systematically studied in Maowusu sandy Land. The results were as follows:(1)the empirical equation θ=AS^(-B) could well simulate the water characteristic curves of the soil.The study also showed that the soil had the low moisture capacity and the less supply water and low drought endurance.(2)The main resistance of water distribution in SPAC was from leaf to atmosphere,the distinctly seasonal change of soil moisture was the common result of rainfall,evaporation from the forest floor and transpiration of the trees,the tree tested had a clear daily variation in leaf potential,under the condition of drought stress,the lowest leaf potential appeared in advance,leaf water potential had a correlation with soil and atmosphere water potential to a certain extent.
出处
《林业科学研究》
CSCD
北大核心
2004年第B12期31-38,共8页
Forest Research
基金
国家重点科技攻关西部专项课题"宁夏防沙治沙及沙产业技术开发"(2001BA901A34)
关键词
土壤含水量
土壤水势
土壤水分特征
叶水势
大气水势
soil moisture content
soil water potential
the water characteristic curves of the soil
leaf water potential
atmosphere water potential
