Effects Of Simulated Warming On Soil Microbial Community In Alpine Grassland

The warming experiment has an irreplaceable role in studying the response and adaptation mechanism of terrestrial ecosystems to global warming,and soil microorganisms are the key components of soil ecosystems.In this paper,in order to explore the dynamic changes of alpine grasslands under the influence of global warming,a simulated temperature increase control experiment was conducted in Yushu Prefecture,Qinghai Province to study the effects of simulated temperature increase on alpine grassland vegetation,soil physical and chemical properties,and soil environmental factors.High-throughput sequencing was used to analyze the diversity of microorganisms in the samples with and without warming in different soil layers,and then the correlation between environmental factors and soil microorganisms was analyzed.The results are as follows:1.Under the simulated warming test for six consecutive years,the number of species has a negative correlation with temperature,the plant height and biomass has a positive correlation with temperature.The alpha diversity survey found that the shannon index and pielou index of 2013 control group is higher and the difference is significant(P<0.05).The shannon index and pielou index of warming in 2018 were lower,and the difference was significant(P<0.05).The margalef richness index shows that the temperature increase in 2018 is higher,and the temperature increase in 2013 is lower,the difference is significant(P<0.05).2.Simulated temperature increase has no significant effect on soil carbon,nitrogen,microbial biomass carbon,microbial nitrogen,and ammonium nitrogen in the same soil layer of alpine meadow(P>0.05),and it affects soil carbon,nitrogen,microbial biomass carbon,Microbial nitrogen,organic matter and nitrate nitrogen were significantly different(P<0.05),and showed a trend of 0-15 cm>15-30 cm.As for the soil p H,simulated temperature increase has no significant effect on the soil p H of the same soil layer in the alpine meadow(P>0.05),and it has a significant difference between different soil layers(P<0.05),and shows 15-30 cm>0-15 cm trend.3.In the 0-15 cm soil layer outside the temperature-increasing cell,the soil temperature and soil conductivity are positively correlated(P<0.01),and the soil moisture and soil conductivity are positively correlated(P<0.01);In the15-30 cm soil layer,soil temperature is negatively correlated with soil electrical conductivity(P<0.05),and soil moisture is positively correlated with electrical conductivity(P<0.01).4.The community structure analysis?diversity analysis?multi-dimensional scale analysis and principal coordinate analysis of prokaryotes and fungi found that Fa?Fb?Ma and Mb were not significantly different.5.High-throughput sequencing results found that the soil in this area is rich in microbial communities,and the most abundant prokaryotes are Acidobacteria(Acidobacteria),Actinobacteria,and Proteobacteria;the most abundant The fungus is Ascomycota(Ascomycota).There was no significant difference in soil microbial community between samples(P<0.05).Combined with the results of environmental factors,the Canonical Correlation analysis of the microbial community found that ammonium nitrogen?plant height and species number had a higher effect on the structure of the prokaryotic community,and the conductivity had a higher effect on the structure of the fungal community.