Study On The Characteristics Of Soil Microbial Community And Soil Multifunction In Meadow Ecosystem

As a large country of grassland resources,grassland in China is mainly concentrated in the north and northwest,of which Inner Mongolia and Qinghai Tibet Plateau are the main distribution areas of meadow ecosystem.Meadow ecosystem is the main base of forage production,and also plays an important role in soil and water conservation.Microorganisms are an important part of meadow ecosystem,which is of great significance to maintain the structure and function of meadow ecosystem.However,the cognition of soil microbial community characteristics and soil multifunctional in different meadow ecosystems is still very weak,especially the driving factors of soil multifunctional are less understood.In this study,field investigation of vegetation communities and soil sample collection were carried out in temperate meadows in Inner Mongolia and alpine meadows in Qinghai Tibet Plateau.There were 13 sample points in temperate meadows and 6 sample points in alpine meadows,with three repetitions,a total of 57 samples.Using high-throughput sequencing technology to explore the distribution characteristics of microbial community composition in different meadow ecosystems;Single factor analysis of variance(ANOVA),t-test and other statistical methods were used to evaluate the differences of microbial communities and ecological functions among different meadow ecosystems;Correlation analysis was used to reveal the correlation between microbial community characteristics and environmental factors and soil versatility.The main results are as follows:(1)10 indexes of climate and soil physical and chemical properties were tested.There are significant differences in temperature,rainfall,available phosphorus,available potassium,ammonia nitrogen,nitrate nitrogen and nitrite nitrogen among different meadow ecosystems(p<0.05),and except for nitrate nitrogen,other climate and soil physical and chemical property indicators with differences show alpine meadow > temperate meadow.(2)Vegetation in different meadow ecosystems showed a degradation trend.There were significant differences in the diversity of plant Shannon in different meadow ecosystems(p=0.011),and temperate meadow(H′=2.17)> alpine meadow(H′=1.79).(3)There are significant differences in the abundance and diversity of microbial communities in different meadow ecosystems.Temperate meadow microbial community α The diversity was significantly higher than that of alpine meadow(p<0.01).The interpretation degree of soil total nitrogen content to bacterial community is the highest,the interpretation degree of temperate meadow is 77.8%,and the interpretation degree of alpine meadow is 90.7%;Soil organic carbon had the greatest impact on the fungal community in temperate meadow(65.5%);Available potassium had the greatest impact on the fungal community in alpine meadow(76.1%).(4)There were significant differences in the construction process of microbial communities in different meadow ecosystems(p<0.01).In the meadow ecosystem,the deterministic process dominated the construction of soil bacterial communities,while the stochastic process dominated the construction of soil fungal communities.(5)There were significant differences in soil multifunctional index among different meadow ecosystems(p<0.001),and the soil multifunctional index of temperate meadow(0.531)was higher than that of alpine meadow(0.358).The results of least square structural equation model showed that the soil versatility of temperate meadow was mainly affected by the diversity of fungal community(0.109),and that of alpine meadow was mainly affected by rainfall(1.725)and plant community diversity(0.490).