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通过选择3个具有不同地质背景、气候条件等环境特征的山西汾阳马跑-郭庄岩溶泉域、湖南湘西大龙洞地下河流域、广西桂江流域,对流域内具有代表性的不同土地利用方式和覆被类型下垫面土壤20～50cm深处CO2浓度进行检测。结果显示,土地利用方式和覆被变化对3个流域岩溶土壤中20cm、30cm、40cm和50cm深处CO2浓度具有明显的影响作用:湖南湘西大龙洞地下河流域多数样地土壤CO2表现为随土层的加深先增加后降低的双向梯度;山西马跑-郭庄泉域玉米地的土壤CO2浓度比种植马铃薯的高,且随着覆被条件由草地→灌丛→林地的改善,土壤的扰动性变小,CO2浓度差趋于减少,变幅趋于稳定。各个流域相同覆被类型,群落结构和优势种变化越小,土壤CO2浓度变幅越小。
By selecting three horse-run Kuang-Guozhuang karst springs in Shanxi Province, Dalongdong underground river in western Hunan Province and Guangxi Gui River watershed with different geological backgrounds and climatic conditions, Methods and types of underlying surface soil 20 ~ 50cm depth of the test CO2 concentration. The results show that the changes of land use patterns and cover have a significant effect on the CO2 concentrations in the depths of 20cm, 30cm, 40cm and 50cm in the karst soil of the three watersheds: Most of the soil CO2 in the Dalongdong underground river basin in Hunan Xiangxi shows as follows: The deepening of soil layer increased first and then decreased in two-way gradient. The soil CO2 concentration of maize field in Shanxi Ma Run-Guozhuang spring field was higher than that of potato planted. With the improvement of covering conditions from grassland to shrubland to woodland, Small, CO2 concentration difference tends to decrease, the amplitude tends to be stable. The same types of vegetation in all watersheds, the smaller the changes of community structure and dominant species, the smaller the amplitude of soil CO2 concentration.