摘要
土壤胞外酶在生态系统生物地球化学循环过程中扮演着重要角色,然而关于土壤胞外酶活性的主控因子研究还不够深入,特别是在偏碱性的钙质土壤区域相关研究尤其缺乏.本研究以典型喀斯特山区(木论国家级自然保护区)的林地为研究对象,采集不同地形条件(不同坡位和坡向)、不同树种(厚壳桂和伞花木)下的表层土壤(0~15 cm),测定了与碳、氮、磷循环相关的6种水解酶的活性及相关土壤理化性质.研究运用方差分解,并结合多响应置换过程以及冗余分析技术分析了地形、树种和土壤理化性质对土壤酶活性的影响.结果表明,坡位对土壤酶活性有显著影响.树种和坡向对土壤酶活性的影响不显著.方差分解结果表明,地形、树种和土壤理化性质共同解释了土壤酶活性变化的55.3%,其中土壤因子是影响酶活性改变的主要因子,解释了44.2%的变异.而冗余分析的结果进一步表明在土壤因子中,pH、总氮和无机氮是影响土壤酶活性变化的主要指标.研究首次量化了喀斯特地区小尺度内地形、树种及土壤理化性质对土壤酶活性变化的影响.研究也说明了在喀斯特山区小尺度内土壤酶活性的变化可由土壤理化性质来表征.
Soil extracellular enzymes are crucial in biogeochemical cycle and ecosystem functioning. Yet uncertainty exists in terms of major determinants on soil extracellular enzyme activity （EEA）, especially at calcareous areas. In this study, soil samples （0-15 cm） were collected from different topographic conditions （different slope positions and aspects） and different tree species （Cryptocarya concinna and Eurycorymbus cavaleriei） in a forest located at Mulun natural reserve, a typical karst area. Six hydrolytic enzymes, related to carbon, nitrogen or phosphorus cycling, and soil physiochemical properties were investigated. The effects of topography, tree species and soil properties on soil enzyme activities were analyzed by multi-response permutation procedures （MRPP）, redundancy analysis （RDA） and variation partitioning. The enzyme profiles were significantly （P〈0.05） separated among the four slope positions but not significantly separated between the two aspects or two tree species according to multi-response permutation procedure （MRPP） analysis. Variation partitioning indicated that topography, tree species and soil properties together explained 55.3% of EEA variation. Soil property was the key factor influencing EEA variation, which explained 44.2% of EEA variation. The result of redundancy analysis （RDA） showed that soil pH, total nitrogen and inorganic nitrogen were the most important variables among the nine soil properties for EEA variation. This study first quantified the effects of small-scale topographic, tree species, and soil properties on soil enzyme activity variation in karst areas. Our results suggest that EEA variation can be well explained by soil properties at a small scale in the karst area.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第6期2577-2585,共9页
Environmental Science
基金
国家重点研发计划项目(2016YFC0502404)
国家自然科学基金项目(31500405,41571295,31400462)
中国科学院百人计划项目(Y523101030)
中国科学院STS项目(KFJ-EW-STS-092)
关键词
土壤胞外酶活性
地形
树种
土壤属性
喀斯特
soil extracellular enzyme activity
topography
tree species
soil properties
karst
