高寒矮嵩草草甸植物生长季土壤水分动态变化规律

利用2001年和2003年土壤水分观测资料分析了中国科学院海北高寒草甸生态系统定位站(海北站)矮嵩草草甸土壤水分的日变化、植物生长季期土壤水分的季节变化及垂直变化规律。结果表明:高寒矮嵩草草甸土壤水分的日变化在各季节表现出早晚高,中午低的U型分布变化;在植物生长季土壤水分的季节变化与植物生长、土壤消融与冻结、气候条件等有很大的联系,少降水年与多降水年变化基本一致;土壤水分随土层深度增厚而降低;根据植物根系对土壤水分利用情况将土层分为根系利用层和根系微利用层。

Study on the Soil Water Dynamics of Kobresia Humilis Meadow in Growing Season

The dynamic changes of soil water in growing season on Kobresia humilis meadow was studied according to the data of soil water in 2001 and 2003.The results indicated that the diurnal variation of soil water on Kobresia humilis meadow showed a "U" type change.Soil water content was higher in the morning and the evening,but was lowest at noon.Soil water content in growing season was strongly correlated to the growth of plant,soil melting and freezing and changes of climate.The changes of soil water content were the same in the dry year and in the wet year.The profile change showed that soil water content in surface layer was higher than that in middle layer and in under layer in 2001 and 2003.Surface layer(0-20cm) contained more water and more roots.Vegetation mainly used water in this layer;middle floor(20-40) contains less water than surface layer.