中文摘要：

【目的】研究生物质炭输入对杉木人工林土壤碳排放（CO2）和微生物群落组成的影响,为亚热带人工林生物质资源合理利用以及固碳管理提供科学依据。【方法】以福建建瓯万木林自然保护区内的杉木人工林土壤为研究对象,设置不同凋落物条件（未添加凋落物和添加凋落物）,分别输入3种不同温度（350,550和750℃）制备的生物质炭,在25℃条件下培养364天。利用碱吸收法研究杉木人工林土壤CO2排放特征,用磷脂脂肪酸方法（PLFA）分析微生物群落组成。【结果】未添加凋落物条件下,输入3种生物质炭后土壤CO2排放速率随时间延长逐渐降低并趋于平稳,而添加凋落物条件下,输入3种生物质炭后土壤CO2排放速率先上升,7天达到最大值,随后逐渐下降;在不同凋落物条件下（未添加凋落物和添加凋落物）,不同温度制备的生物质炭仅在培养前期阶段对土壤CO2排放存在显著影响（P〈0.05）,输入低温制备生物质炭（BC350）的土壤CO2排放速率高于输入高温制备生物质炭（BC550和BC750）处理,土壤CO2累积排放量也最高;培养前期阶段,输入3种生物质炭处理的土壤CO2累积排放量均高于未输入生物质炭处理的,但在培养后期则低于未输入生物质炭的处理;磷脂脂肪酸分析结果显示,输入3种不同温度制备的生物质炭均影响了杉木人工林土壤微生物群落组成,在未添加凋落物条件下输入生物质炭,革兰氏阴性细菌的丰度显著降低,添加凋落物条件下,生物质炭的输入使放线菌的丰度显著增加;不同温度制备的生物质炭仅在添加凋落物条件下对微生物群落组成影响显著（P〈0.05）,与输入低温制备的生物质炭（BC350）相比,输入高温制备的生物质炭（BC750）使革兰氏阳性细菌的丰度显著增加,真菌的丰度显著下降;相关分析表明,土壤CO2累积排放量和土壤PLFA总量极显著正相关（P〈0.01）。【结

英文摘要：

【Objective】This study aimed to investigate the impacts of biochar input on soil carbon（ CO2） emission and soil microbial community composition in Cunninghamia lanceolata plantation,which provided the valuable information for the biomass resources use and the carbon sequestration management for plantations in subtropical China. 【Method】Soil was collected from the C. lanceolata plantation at Wanmulin Nature Reserve of Fujian province. Biochars,produced by charring C. lanceolata at three different temperatures（ 350 ℃,550 ℃ and 750 ℃）,were mixed with soils with or without addition of C. lanceolata litter,respectively,and then the mixture was incubated in the dark at 25 ℃ for 364 d.We used the alkali absorption method to observe soil CO2 emission dynamic and utilized phospholipid fatty acid（ PLFA）analysis to characterize the soil microbial community composition. 【Result 】Soil CO2 emission rates declined with the incubation time and tended to be stable at the late stages of incubation with biochar addition. However soil CO2 emission rates increased at the early stages and reached the maximum at 7 d and then decreased with biochar and litter addition.Regardless with or without litter addition,the pyrolysis temperature of biochar only significantly influenced soil CO2 emission at the early stages of incubation（ P〈0. 05）,and the soil CO2 emission rates with addition of BC350（ biochar produced at 350 ℃） were higher than with BC550（ biochar produced at 550 ℃） and BC750（ biochar produced at 750℃）,and biochar produced at lower temperature（ BC350） resulted in more cumulative soil CO2 emission. The cumulative soil CO2 emission with biochar was higher than that without biochar at the early stages of incubation,however,it was lower at the late stages. PLFA analysis showed that the biochar input influenced the soil microbial community composition. The abundance of Gram-negative bacteria significantly decreased in soils with biochar but without litter addition,while the ab