摘要
选择滇东南普者黑峰林湖盆区内菜花箐上坡位石沟、中坡位土面和下坡位土坡3个喀斯特小生境,通过对降水、表层岩溶水、土壤水及优势树种木质部水进行氢氧稳定同位素测定,探讨喀斯特小生境土壤水运移机制及影响因素.结果显示:(1)土壤水分主要来源于大气降水和表层岩溶水,石沟土壤容重小,孔隙度大,水分状况良好,雨季表层土壤水δ18O变异程度大,旱季时表层和深层土壤水δ18O变异程度较小,土壤水活塞流和优先流并存,以优先流补给为主;(2)土面上层土壤非毛管孔隙度大,降水快速下渗,雨季各层土壤水δ18O变异程度高,旱季较低,深层出现最低值.运移模式多为活塞流,植被优势种清香木旱季利用浅层土壤水较多,雨季利用表层岩溶水较多;(3)土坡蒸发作用弱,深层土壤水δ18O变化范围缩小,雨季表层变异大于深层,旱季时深层变异程度大.基质流混合作用强,以活塞流运移为主,上层存在优先流.随着植被恢复,清香木和云南松相比于灌丛更趋向于利用表层岩溶水等稳定的水源.
To investigate the mechanism and influential factors of soil water movement in karst environment in southeastern Yunnan Province,Caihuaqing slope in forest-lake basin of Puzhehei was chosen as the study area.Hydrogen and oxygen composition of precipitation,Epikarst water,soil water and xylem water of dominant tree species from 3 kasrst niches,which included the upper slope of stone gully,middle and lower parts of soil surfaced slope were determined using stable isotopes labeling technology.The results showed that(1)soil water mainly came from meteoric water and surface karst water.Stone gully soil was highly porous,with low bulk density and satisfactory water regime.The variation degree of oxygen-18 was high in surface soil during rainy season and low in both surface and deep soils during dry season.Piston flow of soil water coexisted with preferential flow,with the latter being the main supply.(2)Non-capillary porosity of the upper soil layer was high so that precipitation infiltrated rapidly.The variation degree of oxygen-18 was high in rainy season and relatively low during dry season in all soil layers,with the minimum value being from deep soil layer.Piston flow was the dominant supply.For the dominant species Pistacia weinmannifolia,shallow soil water was the main water supply in dry season and it utilized more Epikarst water in rainy season.(3)With weak evaporation from soil slope,the variation range of oxygen-18 narrowed for deep soil water while it rose during dry season.The variation degree of surface layer exceeded deep layer in rainy season.The mixing effect of matrix flow was strong,with piston flow being the main movement process.It also had preferential flow on the upper layer.With the restoration of vegetation,Pistacia weinmannifolia and Pinus yunnanensis tended to use water of stable sources such as surface karst water compared with thickets.
作者
牟洋
范弢
户红红
MOU Yang;FAN Tao;HU Honghong(College of Tourism and Geographic Sciences,Yunnan Normal University/Yunnan Provincial Key Laboratory of Plateau Geographical Processes and Environmental Change,Kunming,Yunnan 650500,China)
出处
《福建农林大学学报（自然科学版）》
CSCD
北大核心
2020年第4期540-549,共10页
Journal of Fujian Agriculture and Forestry University:Natural Science Edition
基金
国家自然科学基金地区项目(41661004)
国家自然科学基金地区项目(41261007)。
