亚高山不同植被类型区的雨季岩溶溶蚀速率研究

关于岩溶溶蚀速率,前人在研究中肯定了岩溶区内CO2浓度的时空变化对溶蚀速率的驱动作用,然而不同的植被条件产生的土壤理化性质差异和变化对溶蚀速率的方向和强度也具有较大的影响.通过野外溶蚀标准试片法,测试得出重庆金佛山岩溶区碧潭泉和水房泉两泉域4种典型植被类型下的5个测试点的雨季绝对溶蚀量和平均面积溶蚀量.测试结果表明不同植被条件甚至同一植被类型下不同海拔下岩溶区石灰岩标准试片的溶蚀速率都存在较大差异,5个测试点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.通过测试点的土壤基本理化性质分析得出以下结论:在研究区研究时间内的降雨量、温度差异的基础上,除了土壤CO2浓度,土壤有机质也是控制金佛山两泉域岩溶速率的主要因素之一.

Karst Dissolution Rates of Areas with Different Vegetation Types in the Sub-mountain Region

Previous studies of karst processes were mainly focused on summarizing the driving effect of CO2 density change on the karst process in a certain karst area.Nevertheless,the direction and intensity of the karst process could be deeply affected by soil physical and chemical variations resulting from land cover.Using the method of standard limestone tablets,the authors detected the corrosional ratios and average corrosional rates of four different vegetation types on the basis of the observation of karst districts of Bitan and Shuifang springs in the Jinfo Mountain in the summer of 2006.Almost all the vegetation types occurred in a small study area,so the present study was typical and representative.The results show that the corrosional ratios of different vegetation types at different elevations are quite different.In general,the corrosional ratios increase gradually from the forest land of Shuifang spring,through the bamboo forest land of Shuifang,the meadow of Shuifang and the forest of Bitan spring,to the shrub of Bitan spring.On the basis of rainfall and temperature differences in the two springs,it is concluded that,besides soil CO2,soil organism is one of the major factors controlling the karst dissolution rate in these districts.