典型岩溶区不同土地利用方式下雨季、旱季岩溶作用研究

Impact of land-use patterns upon karst processes in typical karst regions of Jinfo Mountain

2006年4月—2007年4月,通过野外溶蚀标准试片法,测试得出重庆金佛山岩溶区山腰碧潭泉和山顶水房泉两泉域5种典型土地利用方式下的6个测试点雨季和旱季溶蚀量。测试结果表明:雨季溶蚀量明显高于旱季,位于生态保护良好的山顶原始生态区测试点溶蚀率高于保护区、非保护区交界地带且受人类活动影响较大的山腰测试点;同一时段内不同土地利用方式下的测试点溶蚀速率也存在较大差异;6个测试点的年均溶蚀量由大到小依次为:水房泉竹林地>水房泉林地>水房泉草地>碧潭泉林地>碧潭泉灌草丛>碧潭泉耕地。从测试点的土壤基本理化性质分析得出,在研究区域内局地气候(降雨量、温度)影响的基础上,除了土壤CO2浓度,土壤有机质也是控制两泉域岩溶速率的主要因素之一。

It has been recognized that intensity of karst processes could be largely affected by soil＇s physical and chemistry properties. Then, less attention was paid to the impact of land-use types on karst processes in mountain area. Filed dissolution test of standard limestone tablets, carried out in the karst regions of Bitan spring which located on 800 m elevation and Shuifang spring which located on 2 100 m elevation in Jinfo mountain of Chongqing during rainy season and dry season of 2006 -2007, where five types of land-use and six test sites were encountered. Almost all the typical land-use types occurred in the small study area, so the present study is also typical and representative. The results showed that the corrosion ratio was some difference between the rainy season and dry season, and at different elevations is quite different that corrosional ratio in Shuifang spring is more quicker than that of in Bitan spring during the test time, revealed that limestone dissolution was related to corrosion speed of the soil, and the soil＇s corrosion speed was different with land-use types in study area. Six test points average content of organic matter in soil profile arranged in descending order： forest of Shuifang spring〉 bamboo forest land of Shuifang spring〉meadow of Shuifang spring〉forest of Bitan spring〉shrub of Bitan spring 〉tilled land of Bitan spring.