长江流域不同地质生态环境土壤碳酸酐酶活性、有机碳含量及其相关性

Soil carbonic anhydrase activity,soil organic carbon and their relationships in different geological eco-environments of the Changjiang River basin

为了探讨流域岩溶生态系统土壤碳酸酐酶（CA）活性、有机碳含量及CA固碳之间的潜在关系,选取长江流域干流及支流沿岸不同地质生态环境下的10个样地,比较长江流域不同地质生态环境下表层土壤（0--20cm）中的碳酸酐酶（CA）活性与土壤有机碳（SOC）含量,并分析二者之间的关系。结果表明：（1）长江流域岩溶区的表层土壤CA活性要高于非岩溶区（P〈0.01）,土壤CA活性的差异与样地的地质类型及植被类型不同有关;（2）位于岩溶区高场（GC）样地的年平均SOC含量最高（1.09%）,而位于非岩溶区外洲（WZ）样地的年平均SOC含量最低（0.29%）,而且总体比较而言,长江流域冬季表层土壤的平均SOC含量显著高于夏季（P〈0.01）;（3）相关性分析结果显示,不同季节长江流域岩溶区表层土壤CA活性与SOC含量呈一定的正相关。研究结果为进一步研究流域岩溶生态系统土壤CA与土壤固碳能力之间的关系奠定了基础。

Ten sampling plots in different geological eco environments were selected along the main stream and tributaries of the Changjiang River basin. Carbonic Anhydrase （CA） activity and Soil Organic Carbon （SOC） content in surface soils （0420 cm） were studied and relationships between CA activity and SOC con tent were discussed. The results were as follows. （1） The CA activities in surface soils of karst areas were higher than those in non-karst areas （P〈0.01）. Different geological types and vegetation types resulted in different CA activities. （2） The plot GC in karst areas had the highest annual average SOC content （1.09%） while the plot WZinnon-karst area had the lowest annual average SOC content （0.29%）. Moreover, the av- erage surface SOC content in winter was significantly higher than that in summer （P〈0.01）. （3） Correla tion analysis showed that CA activities in karst surface soils correlated positively with SOC contents in all seasons. The result of this paper laysa foundation for further studies on the role of soil CA in carbon seques- tration in karst ecosystems of river basins.