以南京市溧水区林场间伐9年后的29年生马尾松人工林为研究对象,探讨了不同间伐强度(对照:0%;弱度间伐:25%;中度间伐:45%;强度间伐:65%)对土壤3种活性有机碳含量及其在总有机碳中比例的影响。结果表明:与对照样地相比,中度间伐显著提高了土壤总有机碳含量,强度间伐显著降低了土壤总有机碳含量;土壤颗粒有机碳与易氧化有机碳含量对间伐的响应与总有机碳规律一致,土壤轻组有机碳含量在3种间伐强度下显著降低,表现为强度间伐<弱度间伐<中度间伐<对照;土壤颗粒有机碳、轻组有机碳及易氧化有机碳在总有机碳中的比例分别为30.83%~64.59%、10.40%~26.92%、3.61%~4.62%。3种间伐强度显著降低了土壤轻组有机碳在总有机碳中的比例,对土壤易氧化有机碳在总有机碳中的比例无显著影响,中度间伐显著降低了土壤颗粒有机碳在总有机碳中的比例。中度间伐利于土壤总有机碳的积累,且土壤有机碳稳定性高。 The 29-year-old masson pine plantations in Lishui District, Nanjing were used as the study object to investigate the effects of different thinning intensities (control: 0%; thinning: 25%; moderate thinning: 45%; %) On the three kinds of active organic carbon in soils and their proportion in total organic carbon. The results showed that compared with the control plots, moderate thinning significantly increased soil total organic carbon (TOC), and the intensive thinning significantly reduced total organic carbon (TOC). The responses of soil organic carbon (SOC) and readily oxidizable organic carbon The results showed that there was a significant reduction in soil organic matter (SOC) under the three kinds of thinning intensities under the three kinds of thinning intensities, which were the intensity thinning