城市不同功能区绿地土壤有机碳矿化和酶活性变化

Changes of Soil Organic Carbon Mineralization and Enzyme Activities from Different Urban Functional Areas

作者研究了城市不同功能区绿地土壤有机碳矿化过程动态,为正确认识城市土壤有机碳稳定机制,制定科学的养分管理措施及深入了解和评价城市土壤的功能特性和生态环境效应有重要的科学参考意义。采用室内恒温培养法观测了城市不同功能区绿地土壤有机碳矿化的过程动态和酶活性变化。结果表明:不同功能区土壤酶活性差异显著,脲酶:公园>学校>居民区>工厂>道路;磷酸酶:公园>工厂>学校>居民区>道路;转化酶:居民区>公园>工厂>道路>学校;但不同功能区土壤有机碳矿化过程动态表现出相同规律,在培养前期有机碳矿化速率迅速下降,培养中期缓慢下降,培养后期保持相对稳定的趋势,有机碳矿化与培养时间符合对数关系;整个培养期内,土壤有机碳矿化速率及累计矿化量公园>工厂>道路>学校>居民区。统计分析表明,土壤有机碳矿化速率与土壤有机碳,水溶性有机碳以及微生物生物量碳含量显著相关,相关系数分别为0.850、0.689、0.485;土壤酶与土壤有机碳矿化没有直接的相关性,但脲酶、转化酶与土壤微生物生物量碳之间相关系数分别为0.606和0.642,间接影响土壤有机碳的矿化。

The dynamic pattern of soil organic carbon mineralization is essential for better understanding the mechanism of soil organic carbon stabilization, ban soil property and its making ecological effects. Through scientific nutrient management and evaluating the ur- incubation tests in laboratory, the mineralization of soil organic carbon （SOC） and enzyme activities of different functional areas were observed. Results showed that enzyme activities were significantly different, urease activity： park〉school〉residence〉industry〉road; phosphates activity： park 〉industry 〉school 〉residence 〉road; invertase activity： residence 〉park 〉industry 〉road 〉 school; But the dynamic patterns of SOC mineralization of different functional areas were similarly, the rate of SOC mineralization decreased quickly at the beginning, and then decreased slowly during the middle incubation time, and keep relatively constant during the later incubation time, and fitted to logarithmic equation with incubation time. Statistic analysis results showed that mineralization rate of SOC were significantly correlated with SOC, water soluble organic carbon（WSOC） and microbial biomass earbon（MBC）, the coefficient is 0.850,0.689,0.485 respectively. Soil enzyme had no direct relationship with SOC mineralization, but the correlation coefficient between microbial biomass carbon with urease and invertase were 0.606 and 0.642, thus have indirect effects on soil organic carbon mineralization.