针阔人工混交林及其纯林对土壤微生物碳循环功能基因丰度的影响  

Effect of Monoculture and Mixed Plantation with Coniferous and Broadleaved Tree Species on Soil Microbial Carbon Cycle Functional Gene Abundance

作　　者：秦佳琪 肖指柔 明安刚[2,3] 朱豪 滕金倩 梁泽丽 陶怡 覃林[1] QIN Jiaqi;XIAO Zhirou;MING Angang;ZHU Hao;TENG Jinqian;LIANG Zeli;TAO Yi;QIN Lin(Guangxi Key Laboratory of Forest Ecology and Conservation/College of Forestry,Guangxi University,Nanning 530004,P.R.China;Experiment Center of Tropical Forestry,Chinese Academy of Forestry,Pingxiang 532600,P.R.China;Guangxi Youyiguan Forest Ecosystem Research Station,Pingxiang 532600,P.R.China;Youyiguan Forest Ecosystem Observation and Research Station of Guangxi,Pingxiang 532600,P.R.China)

机构地区：[1]广西大学林学院/广西森林生态与保育重点实验室,广西南宁530004 [2]中国林业科学研究院热带林业实验中心,广西凭祥532600 [3]广西友谊关森林生态系统定位观测研究站,广西凭祥532600 [4]崇左凭祥友谊关森林生态系统广西野外科学观测站,广西凭祥532600

出　　处：《生态环境学报》2023年第10期1719-1731,共13页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31560109,32071764);广西自然科学基金项目(2020GXNSFAA297208)。

摘　　要：探究土壤微生物碳循环功能基因丰度对深刻理解土壤碳循环机制具有重要作用,然而土壤微生物碳循环功能基因丰度对不同人工林类型的响应特征尚不清楚。以南亚热带马尾松(Pinus massoniana)-格木(Erythrophleum fordii)人工混交林及其纯林为研究对象,基于林地不同土层(0-20、20-40、40-60 cm)土壤样品的宏基因组测序数据以及土壤理化性质和有机碳组分,解析不同林分不同土层间土壤微生物碳循环(碳固定、碳降解和甲烷代谢)功能基因丰度的差异特征及其主导的土壤环境因子。结果表明:马尾松林土壤微生物碳固定功能基因(rcbL、MUT和PCCA)丰度显著高于其他2个林分,这与其土壤总磷(TP)含量较高且微生物生物量碳(MBC)、易氧化有机碳(EOC)、颗粒有机碳(POC)和惰性有机碳(ROC)含量显著较低的影响有关;土壤微生物碳降解功能基因(MAN2C1和bglB)丰度在马尾松林中显著高于混交林(P<0.05),主要受到马尾松林土壤有机碳(SOC)、MBC、可溶性有机碳(DOC)、EOC和ROC含量低的显著影响;马尾松林甲烷代谢功能基因(pmo A-amo A、pmoB-amo B和pmoC-amo C)丰度显著最高,这与土壤SOC、MBC、DOC、EOC和ROC的显著负作用有关。另外,3个人工林土壤微生物碳循环功能基因丰度基本随土壤深度增加而增加,主要与土壤SOC、C/N、MBC、DOC、EOC和ROC含量随土壤深度加深而降低密切相关。总之,马尾松林土壤微生物具有较高碳循环潜力,但3个林分土壤微生物碳循环潜力均随土壤深度增加而增强,土壤有机碳组分是主导3个人工林土壤微生物碳循环功能基因丰度差异的重要因素。Exploring the abundance of carbon cycle functional genes in soil microorganisms is important for understanding the mechanism of soil carbon cycling.However,the response characteristics of soil microbial carbon cycle functional gene abundance to different plantation types are still unclear.Based on the metagenomic sequencing data,soil physicochemical properties,and organic carbon components of soil samples from different soil layers(0–20,20–40,40–60 cm)under the mixed species plantation with Pinus massoniana and Erythrophleum fordii,as well as their pure plantations in south subtropical China,the differences in microbial functional gene abundance related to soil carbon cycling(carbon fixation,carbon degradation and methane metabolism)between different soil layers of different stands,and the dominant soil environmental factors were analyzed.The results showed that the abundance of soil microbial carbon fixation functional genes(rcbL,MUT and PCCA)in the Pinus massoniana stand was significantly higher than that in the other two stands.This difference was attributed to higher soil total phosphorus(TP)content and significantly lower contents of microbial biomass carbon(MBC),easily oxidizable organic carbon(EOC),particulate organic carbon(POC),and recalcitrant organic carbon(ROC)(P<0.05).The abundance of carbon degradation functional genes(MAN2C1 and bglB)was significantly higher in the Pinus massoniana stand than that in mixed plantation.These differences were mainly affected by the low content of soil organic carbon(SOC),MBC,dissolved organic carbon(DOC),EOC and ROC in Pinus massoniana plantation.The highest abundance of methane metabolism functional genes(pmoA-amoA,pmoB-amoB and pmoC-amoC)was observed in the Pinus massoniana plantation,which was related to significant negative effects of SOC,MBC,DOC,EOC,and ROC.Additionally,the abundance of microbial carbon cycle functional genes in all three planted forests increased with increasing soil depth,mainly due to the decrease in SOC,C/N ratio,MBC,DOC,EOC and ROC con

关 键 词：土壤微生物碳循环功能基因 土壤有机碳组分 宏基因组测序 人工林 南亚热带 

分 类 号：S714.3[农业科学—林学] X171.1[环境科学与工程—环境科学]