岩溶山地典型植被恢复过程中土壤理化性质及微生物特征  

Changes of soil physicochemical and microbial features during the typical vegetation restoration in karst mountain

作　　者：任伟[1] 谢世友[1,2] 谢德体[3] 冯慧芳[1] 

机构地区：[1]西南大学地理科学学院,重庆400715 [2]西南大学三峡库区生态环境教育部重点实验室,重庆400715 [3]西南大学资源环境学院,重庆400715

出　　处：《中国岩溶》2010年第1期35-40,共6页Carsologica Sinica

基　　金：国家"十一五"科技支撑计划课题(2006BAC01A16);重庆市自然科学基金重点项目(CSTC2009BA0002);三峡库区森林生态保护与恢复重庆市重点实验室开放基金

摘　　要：探讨了岩溶山地耕地、1年退耕地、灌草地、15年侧柏疏林地、25年侧柏次生林地植被恢复过程中土壤理化性质和微生物特征的变化。结果表明土壤随着植被恢复的进行,容重先升高后降低,总孔隙度与之相反;各恢复阶段(退耕地、灌草地、疏林地、次生林地)表土>0.25 mm水稳定性团聚体含量较耕地的增幅为5.1%～12.5%,以疏林地最高;团聚体结构破坏率依次降低,各恢复阶段较耕地降幅为34.0%～64.7%,与有机质呈负相关;全N、碱解N等肥力因子含量总体呈逐渐增加的趋势;各恢复阶段中以灌草地pH值最高;表土微生物总数先降后升,各阶段细菌占微生物总数的66.7%～93.3%,放线菌占4.2%～28,8%,同时细菌也是土壤呼吸的主要贡献者。土壤特征的差异性是地表植物组成、凋落物成分及不同指标之间综合作用的结果。Five types of vegetation（farmland, 1-year abandoned farmland, bush-grass land, 15-year scattered woodland（Platycladus orientalis）and 25-year woodland（Platycladus orientalis））are selected to investigate the changes of soil physicochemical and microbial features during the vegetation restoration in karst mountain. The results show that the soil improving process is complicated. Density increases first and then decreases. The trend of bulk density is just opposite to that of total porosity. Soil available water capacity in bush-grass land is the lowest. The amount of 〉0.25 mm soil water stable aggregate content has increased by 5.1%～12.5% in the last four stages than that in farmland, and the amount of 〉0.25 mm soil water stable aggregate content in the bush-grass land is the highest. Aggregate destruction ratio gradually decreases by 34.0%～64.7% from abandoned farmland to woodland with a obviously close correlation with organic matter content. The total nitrogen and available nitrogen have the same increasing trend during the vegetation restoration. The total soil microorganism decreases at first and then increases. The quantity of bacteria group is much higher compared to other two groups at every stages, which accounts for 66.7%～93.3% against the total. The bacteria group is also the most important contributor to soil respiration. The difference for soil characteristic is the result of comprehensive function of surface vegetation composition, litter composition and other different features.

关 键 词：岩溶山地 植被恢复 土壤理化性质 土壤微生物 

分 类 号：S154.1[农业科学—土壤学] S718[农业科学—农业基础科学]