摘要
为探究轮牧对人工混播草地生态系统中植被群落及土壤丛枝菌根(arbuscular mycorrhiza,AM)真菌群落的影响机制,以宁夏盐池县人工混播草地为试验对象,采用单因素随机区组设计,设置T1(无芒雀麦+新麦草+紫羊茅+苜蓿+菊苣)、T2(垂穗披碱草+新麦草+早熟禾+苜蓿+鹰嘴紫云英)、T3(扁穗冰草+新麦草+蒙古冰草+苜蓿)3种混播组合模式,并通过Illumina高通量测序和生物信息学分析,开展轮牧影响下3种人工混播草地土壤AM真菌群落差异性研究,分析人工混播草地生态系统中植被-土壤-AM真菌群落的相互作用关系。结果表明:连续2年轮牧对植被群落生物量产生了显著影响,与轮牧第1年相比,豆科植被群落的相对重要值降低,但禾本科植被群落的相对重要值分别增加了51.16%、81.25%和33.33%。土壤AM真菌中球囊霉属和类球囊霉属为优势属;与轮牧第1年相比,连续轮牧2年后,T1处理的土壤AM真菌群落Chao 1指数较第1年显著降低了12.35%,T3处理的土壤AM真菌群落Chao 1指数、香农-维纳指数、均匀度指数和物种数较第1年分别提升了20.73%、12.80%、7.69%和31.16%(P<0.05),说明T3处理的土壤AM真菌群落对轮牧的响应更加敏感。随轮牧年限增加,T1与T2处理的土壤AM真菌群落组成相似性增加,T1与T3处理的土壤AM真菌群落组成相似性差异较大。连续轮牧2年后,土壤养分对AM真菌群落丰富度的作用强度减弱,但植被群落多样性和植被群落生物量对AM真菌群落丰富度及其组成的作用强度增强;驱动AM真菌群落变化的环境因子由土壤有效磷(p=0.006)和碱解氮(p=0.016)转变为植被群落生物量(p=0.036)。综上所述,不同类型人工混播草地植被群落和土壤AM真菌群落对轮牧表现出不同的响应特征,其中以T3混播组合处理的效果较好。
This study investigated the impact mechanism of rotational grazing on vegetation communities and soil arbuscular mycorrhizal(AM)fungal communities in mixed-sown artificial grassland ecosystems.Taking the mixed-sown artificial grasslands in Yanchi County of Ningxia as the experimental subject,we set up three different patterns of mixed-sown combinations using a one-way randomized block design:T1(Bromus inermis Leyss.+Psathyrostachys juncea Nevski+Festuca rubra+Medicago sativa L.+Cichorium intybus L.),T2(Elymus nutans Griseb.+Psathyrostachys juncea Nevski+Poa annua L.+Medicago sativa L.+Astragalus cicer L.),and T3(Agropyron cristatum+Psathyrostachys juncea Nevski+Agropyron mongolioum Keng+Medicago sativa L.).Illumina high-throughput sequencing and bioinformatics analysis were conducted to investigate the differences of AM fungal communities in the three mixed-sown artificial grassland ecosystems under grazing disturbance,and to analyze the relationships among the vegetation communities,soil physicochemical properties and AM fungal communities.The results indicated that two consecutive years of rotational grazing had a significant impact on the biomass of the vegetation communities.Compared with those after the first year of rotational grazing,the relative importance values of the leguminous vegetation communities decreased,but the relative importance values of the gramineous vegetation communities increased by 51.16%,81.25%and 33.33%,respectively.Throughout both years,Glomus and Paraglomus were the dominant genera of AM fungi in the soil.Compared with that after the first year of rotational grazing,the Chao 1 index of the soil AM fungal community in the T1 treatment significantly decreased by 12.35%after two consecutive years of rotational grazing.Nevertheless,the Chao 1 index,Shannon-Wiener index,evenness index and species number of the soil AM fungal community in the T3 treatment significantly increased by 20.73%,12.80%,7.69%and 31.16%,respectively(P<0.05),which indicates that the soil AM fungal community is more sensitive to grazing intensity during the T3 treatment.The soil AM fungal community structures spatially overlapped between the T1 and T2 treatments and separated between the T1 and T3 treatments with the increase of rotational grazing years.The environmental factors attributed to the alteration of AM fungal communities shifted from available phosphorus(p=0.006)and alkali-hydrolyzable nitrogen(p=0.016)to vegetation community biomass(p=0.036)with the increase of rotational grazing years.After two consecutive years of rotational grazing disturbance,the effects of soil nutrients on soil AM fungal community richness diminished,whereas the effects of vegetation community diversity and biomass on soil AM fungal community richness and composition enhanced.In summary,different types of mixed-sown artificial grassland vegetation communities and soil AM fungal communities exhibit different response characteristics to rotational grazing.Among the three types of mixed-sown artificial grasslands,the combination of T3 is superior.
作者
王媛
米扬
郭蓉
张雨
田霞
王占军
蒋齐
俞鸿千
季波
马琨
WANG Yuan;MI Yang;GUO Rong;ZHANG Yu;TIAN Xia;WANG Zhanjun;JIANG Qi;YU Hongqian;JI Bo;MA Kun(School of Ecology and Environment,Ningxia University,Yinchuan 750021,Ningxia,China;Key Laboratory for Restoration and Reconstruction of Degraded Ecosystems in Northwest China of Ministry of Education,Ningxia University,Yinchuan 750021,Ningxia,China;Institute of Forest and Grassland Ecology,Ningxia Academy of Agriculture and Forestry Sciences,Yinchuan 750001,Ningxia,China)
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2024年第2期231-243,共13页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
宁夏回族自治区农业科技自主创新项目“宁夏饲草产业结构优化调整关键技术研究与示范项目”(NGSB-2021-15-05)
国家自然科学基金项目(31660132)。
关键词
人工混播草地
草地生态系统
丛枝菌根真菌
多样性
轮牧
mixed-sown artificial grasslands
grassland ecosystems
arbuscular mycorrhizal fungi
diversity
rotational grazing
