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sur le développement des zones arides et semi-arides

Titre : Relationship between Population Characteristics of Artemisia Frigida and Rhizosphere and Bulk Soil Microorganisms in Desert Steppe under Different Stocking Rates

Auteur : 刘海丽

Grade : Master 2022

Université : Inner Mongolia Agricultural University

Résumé l
Grazing is one of the utilization methods of grassland.The stocking rate affects the grassland productivity,vegetation characteristics and soil properties of grassland.The changes of plant diversity and soil physical and chemical properties will further affect the community composition and diversity of soil microorganisms.The material exchange and energy flow among plants,soil and microorganisms play an important role in the stability of ecosystem.As an important indicator of grassland degradation,the change of Artemisia frigida population characteristics has great significance to measure the stability of grazing grassland.In this study,Artemisia frigida,a dominant semi shrub plant in Inner Mongolia desert steppe,was taken as the research object.Based on the grazing experiment platform of the comprehensive test and demonstration center of Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences in Siziwang banner,the population characteristics,soil physical and chemical properties,as well as the composition and diversity of prokaryotic microbial communities in rhizosphere and bulk soil of Artemisia frigida under different stocking rates were explored.The correlation between prokaryotic microorganisms in rhizosphere and bulk soil of Artemisia frigida,population characteristics of Artemisia frigida and soil physical and chemical properties were analyzed in order to explore the changes and relationship of prokaryotic microorganisms in rhizosphere and bulk soil of Artemisia frigida under different stocking rates,so as to provide a theoretical basis for the interaction mechanism of plants,soil and microorganisms in desert steppe.The main conclusions are as follows :（1）Stocking rates had significant effects on the population characteristics of Artemisia frigida.The height,coverage,density of vegetative and reproductive branches,cluster diameter and stolon length of Artemisia frigida decreased with the increase of stocking rate.Stocking rates had significant effects on soil p H,total nitrogen,ammonium nitrogen and organic carbon content as well.（2）Stocking rates had significant effects on on the α-diversity index of prokaryotic microorganisms in rhizosphere and bulk soil of Artemisia frigida : at the phylum level,stocking rates had significant effects on Crenarchaeota,Proteobacteria,Firmicutes,Acidobacteria and Unidentified Bacteria.Among the bacteria involved in ammonia oxidation,nitrification,chemical energy heterotrophic,aerobic chemical energy heterotrophic and nitrate reduction,the bulk soil was more affected by stocking rate than rhizosphere soil.（3）According to the correspondence analysis,the diversity index of prokaryotic microorganisms in rhizosphere and bulk soil of Artemisia frigida,the top ten bacteria in annotation abundance and the bacteria involved in ecosystem function were not directly or greatly related to the population characteristics of Artemisia frigida,but were significantly assosiated with soil physical and chemical properties.Among them,ammonium nitrogen was closely related to Crenarchaeota and the bacteria involved in ammonia oxidation

Mots clés : Stocking rate ;Soil prokaryotic microorganisms ;Physical and chemical properties of soil ;Population characteristics ;

Présentation (CNKI)