表层岩溶动力系统中土壤水分及其岩溶效应

对广西弄拉表层岩溶动力系统中森林和灌丛的土壤容重、非毛管孔隙度等物理性质以及土壤CO₂、土壤水和泉水水化学特征进行了研究.结果表明：森林和灌丛环境下的土壤物理性质存在显著性差异，影响土壤含水量.土壤水固定CO₂浓度和土壤CO₂之间存在显著的负相关关系.森林土壤水中游离CO₂浓度为0，灌丛为5.33×10³ mg·m^-3.土壤水和泉水中pH、Ca^2＋、Mg²⁺ 、Cl^-浓度存在一定的负相关关系，其K⁺、Na^＋、HCO₃^-浓度和有机碳含量存在正相关关系.经过雨水的淋溶，土壤层各离子浓度均大幅度增加，其溶蚀能力大大增强.森林环境下的岩溶作用稳定但强度大，灌丛环境下的岩溶作用活跃但强度小.

Soil water and its karst effect in epikarst dynamic system

This paper studied the soil physical properties, soil CO2, soil water and spring water chemistry in a mature forest and a shrub in Nongla of Guangxi, China, as well as the relationships between the chemistry of soil water and spring water, aimed to understand the karst effect of the soil water in Nongla epikarst dynamic system. Significant differences were observed in the soil bulk density and non-capillary porosity under forest and shrub, which affected soil water content. The fixed CO2 in soil water had a significant negative correlation with soil CO2, and the free CO2 in soil water was 0 mg·m-3 in the forest and 5.33×103mg·m-3 in the shrub. In soil water and spring water, there was a negative correlation between pH and Ca2+, Mg2+, and Cl- concentrations, and a positive correlation between K+, Na+, and HCO3- concentrations and organic C content. After the eluviation of rain water, the ion concentrations in leached soil water increased greatly, and accordingly, its corrosion ability enhanced greatly. The karst process in forest environment was stable and intensive, while that in shrub environment was active but weak.