Study On Soil Moisture Characteristics Of Aerial Seeding Plant Community In The Northeast Margin Of Tengger Desert

In this thesis,four plant communities(Hedysarum scoparium community,Calligonum mongolicum + Hedysarum scoparium community,Hedysarum scoparium +Calligonum mongolicum community,Calligonum mongolicum community)in the 1992fly-seeding afforestation area of the northeast margin of the Tengger Desert were taken as the research object,and the soil moisture content characteristics of 0～200cm soil layer of each plant community were monitored by combining traditional sampling and soil moisture monitoring equipment,and the characteristics of plant communities and rainfall data in the study area were combined with the characteristics of plant communities and rainfall data.The changes of soil moisture in different plant communities during the growing season and the relationship between plant communities and soil moisture in fly-seeding afforestation areas were analyzed.The main findings are as follows:(1)The Hedysarum scoparium community,the Calligonum mongolicum +Hedysarum scoparium community,the Hedysarum scoparium + Calligonum mongolicum community,and the Calligonum mongolicum community were typical plant communities in the study area,the vegetation coverage showed the Hedysarum scoparium community at 27%,followed by the Calligonum mongolicum + Hedysarum scoparium community at24%,and the Hedysarum scoparium + Calligonum mongolicum community and he Calligonum mongolicum community had a lower vegetation coverage of 19%.It can be seen from the herb survey that the coverage of herbaceous vegetation in the study area is extremely low,and the average coverage is 2%～4%.(2)The average soil water content of different plant communities before the rainy season showed that the Hedysarum scoparium community(0.566%)> the Calligonum mongolicum community(0.538%)> the Hedysarum scoparium + Calligonum mongolicum community(0.513%)> the Calligonum mongolicum + Hedysarum scoparium community(0.510%).The variation range of total soil water storage before the rainy season was between 15.448～17.786 mm,and the trend of soil depth was consistent with soil water content.(3)The soil moisture of the Hedysarum scoparium community is relatively stable in time,the soil layer is the surface,middle layer and deep layer,the Calligonum mongolicum + Hedysarum scoparium community is the surface,shallow and deep layer,the Hedysarum scoparium + Calligonum mongolicum community is the surface and shallow layer,and the Calligonum mongolicum community is the surface,shallow and deep layer.The regression rate of different plant communities showed that the Calligonum mongolicum community > the Hedysarum scoparium + Calligonum mongolicum community > the Calligonum mongolicum + Hedysarum scoparium community > the Hedysarum scoparium community,the water storage deficit showed the Calligonum mongolicum + Hedysarum scoparium community(97.60%)> the Calligonum mongolicum community(97.57%)> the Hedysarum scoparium + Calligonum mongolicum community(97.56%)> the Hedysarum scoparium community(97.28%),and the soil water storage compensation degree of 0～200cm soil layer of different plant communities was 11.13% for he Hedysarum scoparium community,7.95% for the Calligonum mongolicum + Hedysarum scoparium community,and the Hedysarum scoparium + Calligonum mongolicum community-1.85%,the Calligonum mongolicum community 17.70%.(4)There was a significant correlation between herbaceous coverage,shrub cover,shrub density and soil water content in the Hedysarum scoparium community,among which shrub density had the greatest correlation with soil water content.There was a significant correlation between shrub height,shrub crown width,herbaceous coverage and soil water content in the Calligonum mongolicum + Hedysarum scoparium community,among which herbaceous coverage had the greatest correlation with soil water content.There was a significant correlation between herbaceous coverage and shrub coverage and soil water content in the community of the Hedysarum scoparium +Calligonum mongolicum community,among which the correlation between herb cover and soil water content in the community was the largest.There were significant correlations between herbaceous coverage,shrub cover,shrub death and soil water content in the community of the Calligonum mongolicum community,among which the correlation between shrub death and soil water content was the largest.