【摘要】 在半干旱地区沙地中,如何使有限的降水被植被利用,植被不发生水分亏缺的情况下,植被密度如何?植被依赖于土壤水分环境的分布格局如何?如何对沙地水资源植被利用的管理等?这些对于沙地生态恢复与重建具有重要的意义。根据沙地灌木林群落土壤水分平衡关系的研究,建立了沙地土壤根际水分消耗模型:AET=(1-e-K)Wt或AET=(1-K1)Wt;提出了灌木林密度计算公式:D=(1/ac)(ΣP/ΣAET)1/2或D=(1/ac)(1-β)(ΣP/βΣAET-1);并对沙柳和杨柴两种灌木林群落的土壤水分消耗和密度进行了模拟和计算。沙地灌木林群落土壤根际水分消耗模型和密度公式的物理意义明确,参数易于确定,对于指导固沙造林实践具有重要的价值。模型强调土壤水分平衡关系的原理对于其它类型植被-土壤水分关系的研究也有指导意义。更多还原

【Abstract】 How to make full use of limited precipitation by vegetation, how to design density of vegetation without soil water deficit, how to make disposition of vegetation with soil water landscape and how to manage soil water resources for use of vegetation which all play significant parts in ecological restoration and reconstruction in sand land in semi-arid areas. Based on studies on the relation of soil water balance to shrub community in sand land,established the modeling soil moisture loss from roots of shrub communities such as AET=(1-e^-K)W_t or AET=（1-K₁）W_t and presented the formulas of density of shrub community such as D=（1/a_c）（ΣP/ΣAET）^1/2or D=（1/a_c）（1-β）（ΣP/βΣAET-1）. From that,soil water depletion inboth communities of Salix psammophila and Hedysarum leave were modeled and their densities were calculated. The parameters of these models and density formulas can be easily obtained with clear physical concept. The achievements of the research are valuable for plantation of sand land and for studies on other types of vegetation-soil water relation.更多还原