典型草原区弃耕恢复过程中土壤细菌群落结构变化及其驱动因素  

Changes in Soil Bacterial Community Structure and Driving Factors During the Restoration Process of Abandoned Farmland in a Typical Steppe Region

作　　者：李邵宇 张彬 陈大岭 赵天启 郑佳华 赵萌莉 LI Shaoyu;ZHANG Bin;CHEN Daling;ZHAO Tianqi;ZHENG Jiahua;ZHAO Mengli(College of Grassland,Resource and Environment,Inner Mongolia Agricultural University/Key Laboratory of Grassland Resources,Ministry of Education,Hohhot 010010,China)

机构地区：[1]内蒙古农业大学草原与资源环境学院/草地资源教育部重点实验室,内蒙古呼和浩特010011

出　　处：《中国草地学报》2023年第6期83-91,共9页Chinese Journal of Grassland

基　　金：内蒙古自治区科技计划项目(2020GG0113);国家自然科学基金项目(31861143001);内蒙古农业大学高层次人才引进项目(NDYB2019-5)。

摘　　要：采用空间代替时间的方法,以天然草地为对照,在内蒙古典型草原区域选取不同恢复年限(5年、15年、20年)的弃耕地,通过野外群落调查、植被和土壤取样,结合高通量测序探究弃耕地恢复过程中土壤细菌的演替格局及其主要驱动因素。结果表明:随弃耕年限的增加,植物群落地上和地下生物量、物种丰富度和多样性以及土壤有机碳、pH值、碳氮比和含水量均呈增加趋势;土壤氮磷比、铵态氮和硝态氮含量呈降低趋势,土壤速效磷和全磷无显著变化。土壤细菌物种丰富度与Chao1指数在弃耕5年时最高。土壤细菌在门水平上主要以放线菌门、变形菌门、酸杆菌门和拟杆菌门为主,随弃耕演替进行,放线菌门相对丰度呈先增加后降低趋势,变形菌门相对丰度呈增加趋势;在属水平上主要以鞘氨醇单胞菌属、不明酸杆菌、假单胞菌属和马赛菌属为主,随着弃耕时间的延长,不动杆菌属相对丰度呈先降低后增加趋势,而鞘氨醇单胞菌属的相对丰度逐渐增加。冗余分析表明,土壤有机碳、地上生物量、植物物种丰富度是影响土壤细菌群落的主要因子。综合表明,植被与土壤的变化共同驱动了弃耕地恢复过程中土壤细菌演替格局。This study investigates the succession pattern and driving factors of soil bacteria during the restoration of abandoned farmland in the typical grassland region of Inner Mongolia.Natural grassland was used as a control,while abandoned farmland with different restoration years(5 years,15 years,20 years)were selected in Duolun County,Inner Mongolia,using a spatial approach instead of a temporal one.Field community investigation,vegetation and soil sampling,as well as high-throughput sequencing,were employed to analyze the soil bacterial community.The results showed that various factors exhibited an increasing trend with the increase in abandoned years,aboveground and underground,species richness and diversity,soil organic carbon,soil pH,soil C/N ratio,and soil water content.Conversely,the nitrogen to phosphorus ratio,ammonium nitrogen,and nitrate nitrogen decreased,whereas available phosphorus and total phosphorus remained relatively stable.Notable,the soil bacterial species richness and Chao1 index reached their highest levels five years after abandonment,and the phylum was dominated by Actinobacteria,Proteobacteria,Acidobacteria,and Bacteroidetes at the phylum level.The relative abundance of Actinobacteria initially increased and then decreased,while Proteobacteria showed a consistent increase.At the genus level,Sphingomonas,unidentified_Acidobacteria,Pseu⁃domonas and Massilia were the predominant species.As the duration of abandonment increased,the relative abundance of Sphingomonas increased gradually with the extension of abandonment time,while the relative abundance of Acinetobacter showed a trend of decreasing and then increasing.Redundancy analysis showed that soil organic carbon,aboveground biomass,and plant species richness were the main factors influencing the soil bacterial communities.Collectively,these findings indicated that vegetation and soil dynamics jointly drive the succession pattern of soil bacterial during the restoration process of abandoned farmland.

关 键 词：典型草原 弃耕地 土壤养分 土壤细菌 

分 类 号：S812.2[农业科学—草业科学]