不同岩溶生态系统土壤及其细菌碳酸酐酶的活性分析及生态意义  

Researches on activity of carbonic anhydrase from soil and its bacteria in different Karst ecosystems and its ecological significance

作　　者：李为[1] 余龙江[1] 袁道先[2] 吴云[1] 

机构地区：[1]华中科技大学生命科学与技术学院,武汉430074 [2]国土资源部岩溶动力学开放研究实验室,桂林541004

出　　处：《生态学报》2004年第3期438-443,共6页Acta Ecologica Sinica

基　　金：国家自然科学基金重大研究计划资助项目( 90 2 0 2 0 1 6 );国家自然科学基金资助项目( 40 1 52 0 0 2 ;4 0 30 2 0 34 );国土资源部岩溶动力学开放研究实验室资助项目~~

摘　　要：对能加速岩溶作用的碳酸酐酶 (CA)的来源及分布进行了研究。测定了采自中国西南 4个不同岩溶地区生态系统土壤样品中的 CA活性 ,结果表明在表层土壤中都能检测到 CA活性 ,且 CA活性在不同岩溶生态系统土壤之间存在明显差异 ,其中植被覆盖率低的六盘水米苏嘎的土壤 CA活性最低 ,而植被种类丰富且生长较好的重庆金佛山和马山弄拉等地土壤 CA活性较高。同一类型岩溶生态系统不同岩溶地形的土壤 CA活性亦存在差异 ,植物根际附近土壤 CA活性较高 ,而且土壤 CA活性呈现明显的垂直分布和季节变化 ,表明植物根系及土壤微生物是土壤 CA的主要来源。同时还筛选了能产 CA的细菌 ,并测定了细胞内和细胞外 CA活性 ,结果表明土壤细菌的细胞内和细胞外 CA活性在具有不同植被状况的弄拉和试验场两种不同岩溶生态系统间具有明显差异。这些都暗示着土壤及其细菌The origin and distribution of carbonic anhydrase (CA) which could accelerate Karst processes were explored in this paper. The soil samples used in the experiment were collected from Jinfu Mountain of Chongqing,Misuga of Liu Panshui, Nongla of Guangxi and the Yaji Karst Experimental Site of Guilin, representing different Karst ecosystems of southwest China. The CA activities of the soil samples were determined according to the pH decline method. The results indicated that the CA activity could be detected not only in surface (10~20cm depth) soils of different karst ecosystems, but also in the control plot on a shale and sandstone area. The facts showed that CA, which is widespread in animals, plants and prokaryotes, is present in the environment such as soils where the living organisms exist, through the decomposing and secreting of the living organisms. Because CA can remarkably catalyze the reversible reaction between CO_2 and HCO^-_3, so it might have influence on the surrounding environment. For example, CA might have effects on atmospheric CO_2 precipitation or carbonate rock dissolution. However, these presumptions require further studies. The comparative analysis showed that the CA activity varied obviously among the soils in different karst ecosystems. Of the four kinds of Karst area, the mean CA activity of the surface soil in Misuga of Liu Panshui, which had the lowest rate of covered vegetation, was the lowest at 0.02 U/g dry soil. Nongla and Jinfu Mountain, where there is abundant plant biodiversity and healthy vegetation, had higher mean CA activity in the surface soil with 3.83 U/g dry soil and 3.13 U/g dry soil respectively. The Karst Experimental Site, where the vegetation is not growing as well as at the Nongla and Jinfu Mountain sites, had lower mean CA activity in the surface soil with 2.61U/g dry soil. Moreover, there were certain differences in CA activities in the soils between different kinds of Karst landscape in the same kind of Karst ecosystem. These results suggest that the activity o

关 键 词：碳酸酐酶 CA 土壤 细菌 活性 植被 岩溶地形 岩溶生态系统 

分 类 号：S154[农业科学—土壤学]