摘要
采用经典统计分析与通径分析,研究了桂西北喀斯特峰丛洼地4种植被演替阶段(草丛、灌木林、次生林、原生林)表层(0—15 cm)土壤微生物生物量和土壤酶活性的变化特征,探讨了其与土壤理化性质之间的关系。结果表明:土壤微生物生物量和土壤酶活性随植被正向演替的变化规律并不完全一致。土壤微生物生物量碳、微生物生物量氮和碱性磷酸酶活性整体表现为随植被正向演替而增加。而土壤蔗糖酶活性表现为:次生林>草丛≈灌木林>原生林,脲酶活性表现为:草丛≈次生林≈灌木林>原生林。通径分析结果表明,土壤微生物生物量的直接影响因素和主要影响因素为土壤有机碳;蔗糖酶活性的直接影响因素为土壤有机碳和土壤微生物生物量碳,而从总效应来看,各因素对蔗糖酶活性的影响均较小;脲酶和碱性磷酸酶活性的直接影响因素和主要影响因素均为全氮,但全氮对脲酶活性表现为强烈的负效应,而对碱性磷酸酶活性表现为强烈的正效应。此外,土壤微生物生物量碳、氮及蔗糖酶、脲酶和碱性磷酸酶活性的剩余通径系数均较大,说明存在其它未被考虑因素对其具有影响。
Soil microbial biomass and enzyme activity are sensitive to environmental changes and disturbances; consequently, both parameters have been widely used as indicators of ecosystem responses to vegetation succession. However, there remains no consensus about how these variables change during vegetation succession. This knowledge gap may exist because previous studies usually adopt classical statistical analyses, which are not able to reflect the direct influence of one variable on another. However, with path analysis, direct path coefficients and indirect coefficients may be realized, which allows direct and indirect relationship between multiple independent variables and dependent variable to also be obtained. In the present study, the dynamics and influencing factors of soil microbial biomass and enzyme activity during vegetation restoration were investigated. Soil samples were collected from the upper soil layer （0--15 cm） at four vegetation succession stages （i.e., herb, shrub, secondary forest, and primary forest ） in a typical karst peak-cluster depression area in northwest Guangxi, China. The characteristics of soil microbial biomass and soil enzyme activity were analyzed with classical statistics, while the one-to-one relationships of soil microbial biomass, soil enzyme activity, soil physical properties, and soil nutrients were obtained by path analysis. Overall, soil microbial biomass carbon （ SMBC）, soil microbial biomass nitrogen （SMBN）, and alkaline phosphatase （ALP） activity increased with vegetation succession. Sucrase （SAC） activity was ordered： secondary forest 〉 herb ~ shrub 〉 primary forest. Urease （URE） activity was ordered： herb ~ secondary forest ~ shrub 〉 primary forest. Path analysis revealed that the direct and main influencing factor for soil microbial biomass was soil organic carbon （SOC）. The main influencing factors for SAC were SOC and SMBC, while the total path coefficients of all the factors were small. The main influencing factor for both UR
出处
《生态学报》
CAS
CSCD
北大核心
2015年第21期6974-6982,共9页
Acta Ecologica Sinica
基金
国家973计划项目课题(2015CB452703)
国家自然科学基金项目(31270555,41471445)
中国科学院“西部之光”人才培养计划!
