杉木⁃火力楠混交林降低表层土壤细菌残体积累  

Mixed Cunninghamia lanceolata-Michelia macclurei plantation decreased soil bacterial residue accumulation in topsoils

作　　者：井艳丽 王清奎 JING Yanli;WANG Qingkui(Ecology Security and Protection Key Laboratory of Sichuan Province,Mianyang Normal University,Mianyang 621000,Sichuan,China;Huitong National Research Station of Forest Ecosystem,Huitong 418307,China;CAS Key Laboratory of Forest Ecology and Silviculture,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]绵阳师范学院生态安全与保护四川省重点实验室,四川绵阳621000 [2]湖南会同森林生态系统国家野外科学观测研究站,会同418307 [3]森林生态与保育重点实验室(中国科学院),中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《生态学杂志》2024年第9期2650-2657,共8页Chinese Journal of Ecology

基　　金：杉木用材林定向培育技术研究子课题(2021YFD2201303⁃05);国家自然科学基金项目(31901302)资助。

摘　　要：微生物残体是土壤有机碳的主要组分,其对人工混交林的响应目前尚不清楚。以我国亚热带杉木(Cunninghamia lanceolata)纯林和杉木⁃火力楠(Michelia macclurei)混交林0~20 cm土壤为研究对象,以氨基糖为微生物残体标识物,采用基于革兰氏阳性菌与革兰氏阴性菌比值确定的细菌残体转换系数,研究了长期杉木⁃火力楠混交对土壤微生物残体积累的影响。结果表明,与杉木纯林相比,杉木⁃火力楠混交林0~10 cm土壤细菌残体含量降低了25.3%,进而导致土壤有机碳含量降低了11%。混交林中细菌残体的降低主要归因于大团聚体内细菌残体含量的降低。林木混交并未影响0~20 cm土壤微生物残体含量以及微生物残体对土壤有机碳的贡献。以上结果表明,火力楠引入杉木林35年后降低0~10 cm土壤细菌残体和土壤有机碳的固持,可能不利于维持长期土壤肥力。Microbial residues are major contributors to soil organic carbon(SOC).However,their responses to mixed plantation forests remain unclear.In this study,we examined the accumulation of microbial residues in soil at depths of 0-20 cm in Cunninghamia lanceolata-Michelia macclurei mixed plantation and C.lanceolata pure plantation by analyzing amino sugars and using the ratio of Grampositive to Gramnegative bacteria to determine the conversion coefficient of bacterial residues.The results showed that bacterial residues at depths of 0-10 cm were 25.3%lower in the mixed plantation than that in the monoculture,leading to SOC being 11%lower in the mixed plantation.The lower accumulation of bacterial residues in the mixed plantation was mainly due to the lower accumulation in macroaggregates.However,the accumulation of total microbial residues and their contribution to SOC did not differ between the mixed plantation and monoculture.These results indicate that the M.macclurei and C.lanceolata mixed plantations after 35 years would reduce bacterial residues as well as soil carbon sequestration,which would be detrimental to the longterm maintenance of soil fertility.

关 键 词：氨基糖 微生物残体 土壤碳 杉木 混交林 

分 类 号：S714.3[农业科学—林学]