【作者】 周焱；

【导师】 阮宏华；

【作者基本信息】 南京林业大学 ， 生态学， 2009， 博士

【摘要】 本文选择福建省武夷山国家自然保护区不同海拔高度的4个典型植被土壤,采用野外采样和布置室内培育试验相结合的方法,系统分析了土壤的有机碳库及其矿化特征。结果表明:（1）土壤总有机碳及各活性有机碳含量均随海拔高度的升高而增加,随土层的加深而下降。4种活性有机碳两两间的相关性均达到极显著的正相关。各活性有机碳占土壤总有机碳的比率总的趋势是易氧化碳>矿化碳>微生物生物量碳>水溶性有机碳。土壤总有机碳含量是土壤活性有机碳含量在不同海拔高度上产生差异的主导因子。土壤活性有机碳含量具有明显的季节性变化特征。土壤温度是影响各活性有机碳含量季节变化的重要因子。（2）依据三库一级动力学理论区分的不同海拔高度植被土壤有机碳各库的大小差异明显。土壤活性和惰性有机碳的含量均随海拔高度的升高而增加,缓效性有机碳含量为高山草甸>亚高山矮林>常绿阔叶林>针叶林。（3）经25℃365天室内培养后,不同海拔高度植被土壤的矿化速率在1.67×10^-2～4.46×10^-2gC·kg^-1·d^-1之间,高山草甸的最快,常绿阔叶林的最慢。矿化率在17.5%～22.8%,变化趋势为针叶林>亚高山矮林>常绿阔叶林>高山草甸。土壤矿化速率和矿化率总体上呈现随土层的加深而递减的趋势。不同温度条件下土壤有机碳的矿化量有显著区别。365天培养后,不同土层的Q10平均值,常绿阔叶林为1.46,针叶林为1.46,亚高山矮林为1.41,高山草甸为1.45。同一植被土壤随着土层的加深,Q10值显著减小。更多还原

【Abstract】 In this study, soil organic carbon(SOC) pools and the characteristic of carbon mineralization were systematically studied by sampling analysis and laboratory incubation in four typical vegetation communities along the elevation gradient in Wuyi Mountain. Our results showed that:(1) The amount of total organic carbon(TOC), microbial biomass carbon(MBC), readily oxidation carbon(ROC), water-solubable organic carbon (WSOC) and mineralizable carbon(MC) all increased along the elevation gradient and decreased with the increasing soil depth. The four kinds of labile organic carbon correlated positively with each other. The order of ratios of labile carbon to TOC was: ROC>MC>MBC>WSOC. Statistical analysis found that the most obvious effect of TOC appeared to be as aprimary constraint on the amount of soil labile organic carbon along an elevation gradient. Significant seasonal variation of soil labile organic carbon was found. Soil temperature was the major regulatory factor on the seasonal variations of soil labile organic carbon.(2) The sizes of SOC pools distinguished based on the three-pool theory significantly differed from one another along the elevation gradient in Wuyi Mountain. Both the active carbon and recalcitrant carbon increased along the elevation gradient. The content order of slow carbon was alpine meadow(AM)>sub-alpine dwarf forest(SDF)> evergreen broadleaved forest (EBF)> coniferous forest (CF).(3) SOC mineralization rates were estimated between 1.67×10-2～4.46×10-2gC·kg-1d-1 after 365 days’laboratory incubation at 25℃. The mineralization rate in AM was the highest and in EBF was the lowest. The mineralization ratio was between 17.5%～22.8%, the change trend was CF>SDF>EBF>AM. The mineralization rate and mineralization ratio of SOC decreased across soil depth. The quantity of carbon mineralization differed significantly at different temperature along the elevation gradient. At the end of 365 days’incubation, the average Q10 values was across soil depth were 1.46, 1.46, 1.41, 1.45 in EBF, CF, SDF, AM, respectively. The Q10 values decreased significantly with the increasing soil depth.更多还原