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以桂林会仙喀斯特溶洞湿地及其附近的稻田和旱田表层土壤为研究对象,采用常规方法,测定土壤有机碳和养分含量,并分析二者之间的关系。结果显示,喀斯特溶洞湿地的土壤有机碳含量为(21.77±1.42)g/kg,与稻田的土壤有机碳含量[(22.33±1.19)g/kg]没有显著差异,而旱田土壤有机碳含量为(12.78±0.22)g/kg,比湿地土壤低41.30%。稻田土壤的全氮含量、碱解氮含量、p H、阳离子交换量、交换性钙和交换性镁含量都与喀斯特溶洞湿地土壤无显著差异。但是,上述指标在旱田土壤中较低,降低幅度为15.63%~50.87%。统计结果表明,所有土壤全氮含量和p H与土壤有机碳含量都呈显著正相关(p<0.01);土壤碱解氮、阳离子交换量、交换性钙和交换性镁与土壤有机碳含量都显著正相关(p<0.05)。因此,土壤碱解氮、阳离子交换量、交换性钙和交换性镁对维持喀斯特溶洞湿地和稻田土壤较高的土壤有机碳水平具有重要的作用。
Taking Guixian Karst cave wetland in Guilin as an example, the surface soil of paddy field and paddy field in the vicinity of Guixian was studied. The contents of soil organic carbon and nutrients were determined by routine methods and the relationship between them was analyzed. The results showed that soil organic carbon content in karst cave wetland was (21.77 ± 1.42) g / kg, which was not significantly different from that in paddy field [(22.33 ± 1.19) g / kg], while that in upland soil was ( 12.78 ± 0.22) g / kg, 41.30% lower than the wetland soil. The content of total nitrogen, available nitrogen, p H, cation exchange capacity, exchangeable calcium and exchangeable magnesium in paddy soil were all significantly different from those in karst cave wetland soil. However, the above indicators were lower in upland soils with a decrease of 15.63% -50.87%. The statistical results showed that all the soil total nitrogen and p H had a significant positive correlation with soil organic carbon (p <0.01). The contents of soil available nitrogen, cation exchange capacity, exchangeable calcium, exchangeable magnesium and soil organic carbon Significantly positive correlation (p <0.05). Therefore, soil available nitrogen, cation exchange capacity, exchangeable calcium and exchangeable magnesium play an important role in maintaining soil organic carbon in karst cave wetlands and paddy soils.