间伐对川西亚高山云杉人工林土壤微生物残体碳积累的影响  

Effects of thinning on accumulation of soil microbial residue carbon of Picea asperata plantations in subalpine region of western Sichuan,China

作　　者：井艳丽 李旭华 张袁 张馨月 刘美[2] 冯秋红[1] JING Yanli;LI Xuhua;ZHANG Yuan;ZHANG Xinyue;LIU Mei;FENG Qiuhong(Ecological Restoration and Conservation for Forest and Wetland Key Laboratory of Sichuan Province,Sichuan Academy of Forestry,Chengdu 610081,China;Ecological Security and Protection Key Laboratory of Sichuan Province,Mianyang Normal University,Mianyang 621000,Sichuan,China)

机构地区：[1]四川省林业科学研究院,森林和湿地生态恢复与保育四川省重点实验室,成都610081 [2]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

出　　处：《应用生态学报》2024年第1期169-176,共8页Chinese Journal of Applied Ecology

基　　金：森林和湿地生态恢复与保育四川省重点实验室开放课题(2022KFKT01);四川省自然科学基金青年项目(2023NSFSC0755)资助。

摘　　要：微生物残体是土壤有机碳的重要组分,但长期间伐如何影响微生物残体碳积累特征尚不清楚。本研究分析了未疏伐(对照,4950株·hm^(-2))和间伐(1160株·hm^(-2))14年的云杉人工林表层(0~10 cm)和下层(20~30 cm)土壤理化性质、微生物群落、土壤胞外酶活性和微生物残体碳差异,并揭示间伐对微生物残体碳积累的调控机制。结果表明:与对照相比,间伐显著增加土壤有机碳、全氮、速效磷含量、颗粒有机碳占比、土壤含水量、土壤碳循环水解酶和酸性磷酸酶活性,但显著降低矿物结合态有机碳占比。间伐显著影响真菌残体碳含量、微生物残体碳含量和微生物残体碳对土壤有机碳的贡献,且这些影响与土层无关。间伐处理下真菌残体碳和微生物残体碳含量分别比对照提高25.0%和24.5%。但间伐显著降低了土壤微生物残体碳对土壤有机碳的贡献(降低12.3%),表明土壤有机碳中植物来源碳比例增加。逐步回归分析表明,全氮和含水量是影响真菌残体碳和微生物残体碳积累的关键因子。综上,间伐通过改变土壤性质促进了微生物残体碳的积累,并改变了土壤有机碳来源组成。Microbial residues are an important component of soil organic carbon(SOC).It is unclear how longterm thinning affects the accumulation characteristics of microbial residue carbon(C).We analyzed the differences in soil physicochemical properties,microbial communities,extracellular enzyme activities,and microbial residue C in topsoil(0-10 cm)and subsoil(20-30 cm)in Picea asperata plantation of non-thinned(control,4950 trees·hm^(-2))and thinned for 14 years(1160 trees·hm^(-2))stands,aiming to reveal the regulatory mechanism of thinning on microbial residue C accumulation.The results showed that thinning significantly increased SOC content,total nitrogen content,available phosphorus content,the proportion of particulate organic C,soil water content,C-cycle hydrolase,and acid phosphatase activities,but significantly reduced the proportion of mineral-associated organic C.Thinning significantly affected the content of fungal and microbial residue C,and the contribution of microbial residue C to SOC,and these effects were independent of soil layer.The content of fungal and microbial residue C was 25.0%and 24.5%higher under thinning treatments.However,thinning significantly decreased the contribution of microbial residue C to SOC by 12.3%,indicating an increase in the proportion of plant-derived C in SOC.Stepwise regression analysis showed that total nitrogen and soil water content were key factors influencing fungal and microbial residue C accumulation.In summary,thinning promoted microbial residue C sequestration by altering soil properties and changed the composition of SOC sources.

关 键 词：林分密度 土壤有机碳 土壤微生物 氨基糖 

分 类 号：S791.18[农业科学—林木遗传育种]