为探讨不同植物根系对土壤水分动态变化其及蒸发过程的影响,对贵州喀斯特高原几种灌丛下土壤水分蒸发作了对比研究。结果表明,在土壤持水量的变化上,堆花小檗与小叶平枝栒子根系对土壤最大持水量影响基本一致,持水量最大,矮生栒子的持水量次之,无植被土壤持水量最小;土壤持水量均随着时间的推移逐渐降低,但其持水效果不一致。在土壤累积蒸发量的变化上,随着时间的推移土壤水分蒸发量均逐渐增加,但累积蒸发量的变化大小不同;几种灌丛下10d的土壤水分总蒸发量大小关系与土壤最大持水量的变化一致。用指数函数模型对几种灌丛下土壤水分特征曲线进行拟合,土壤含水量与土壤水分蒸发时间存在较好的相关性,且拟合度较高。

To probe the effect of different plant roots on dynamic change of soil moisture and its evaporation process,soil moisture evaporation under several thickets was compared in Guizhou karst plateau.The results showed that as for the change of soil water holding capacity,roots had no significant difference between Berberis aggregate and Cotoneaster horizontalis var.perpusillus,and the maximum soil water holding capacity was Berberis aggregate=Cotoneaster horizontalis var.perpusillus>Cotoneaster dammerii>no bushes;Soil water holding capacity was reduced with the passage of time gradually but its moisture effect was not consistent for different plant roots.With the change of soil moisture cumulative evaporation,it increased with passage of time gradually but its change was different for different plant roots.10 days of the total soil water evaporation in several bushes had the same change trend with the soil maximum moisture capacity.Based on the exponential function model for soil water characteristic curve in several bushes,there was a good correlation between soil water content and soil moisture evaporation time,and the degree of fitting was higher.