【摘要】 作为土壤质量的重要指标,活性有机碳(SLOC)在土壤物理、化学和生物特性中发挥着重要作用。本研究依托中国科学院会同森林生态试验站,于2016年12月-2017年12月,通过对亚热带常绿阔叶林(烤林)不同季节土壤进行采样和分析,系统地研究和比较了亚热带常绿阔叶林土壤活性有机碳组分季节动态特征。结果表明,(1)不同季节亚热带常绿阔叶林土壤养分和有效养分均大致表现为夏季>秋季>春季>冬季,其中不同季节土壤全磷含量差异不显著(P>0.05)。(2)土壤易氧化有机碳(EOC)、颗粒有机碳(POC)、轻组有机碳(LFOC)和水溶性有机碳(WSOC)具有明显的季节动态,均表现为夏、秋季较高,春、冬季较低。(3)亚热带常绿阔叶林土壤微生物量碳(SMBC)和微生物量氮(SMBN)均大致表现为夏季>秋季>春季>冬季,其中夏季和秋季差异不显著(P>0.05),春季和冬季差异不显著(P>0.05),夏季和秋季显著高于春季和冬季(P<0.05),而不同季节SMBC/SMBN差异不显著(P>0.05)。(4)土壤活性有机碳与土壤总有机碳均呈显著线性关系,说明土壤活性有机碳依赖于土壤总有机碳含量,各自从不同角度表征了土壤中活性较高部分碳的含量。(5)亚热带常绿阔叶林土壤EOC、POC、LFOC、WSOC和SMBC与SOC、TN均呈显著或极显著相关性,与TP相关性不显著;活性有机碳各组分之间相互影响和密切联系,其中SOC、TN是亚热带常绿阔叶林土壤活性有机碳变化的重要影响因素。更多还原

【Abstract】 As an essential indicator of soil quality, soil labile organic carbon(SLOC) and its fractions play an important role in many soil chemical, physical and biological properties. Here, a field experiment was conducted to determine the seasonal dynamics and content of soil labile organic carbon in subtropical evergreen broadleaved forest. The results as follows:(1) The soil nutrients and available nutrients had a similar change trend with the order of summer>autumn>spring>winter, while the soil total phosphorus had no significant difference in different seasons(P>0.05).(2) Easily oxidized organic carbon(EOC), particulate organic carbon(POC),light organic carbon(LFOC) and water-soluble organic carbon(WSOC) had the obvious seasonal dynamics, which showed summer>autumn>spring> winter.(3) Soil microbial biomass carbon(SMBC) and soil microbial biomass nitrogen(SMBN) also had the obvious seasonal dynamics, which showed summer>autumn>spring>winter, and SMBC and SMBN in summer and autumn were significantly higher than that of spring and winter(P<0.05), while SMBC/SMBN had no significant difference in different seasons(P>0.05).(4) There was a significant linear relationship between SOC and SLOC, indicating that soil active organic carbon depended on soil total organic carbon content. And(5) there was a significant relationship among EOC, POC, LFOC, WSOC, SMBC and soil organic carbon(SOC), total nitrogen(TN), while no significant relationship with total phosphorus(TP), which suggested that the components of soil labile organic carbon were closely related, and SOC and TN was the mainly driving factors to soil labile organic carbon in subtropical evergreen broadleaved forest.更多还原