Relationship Between Vegetation Dynamics And Environment In The Eastern Edge Of Kubuqi Desert

In this paper we selected the sandy land,semi-fixed sandy land and fixed sandy land as the search objects,based on the data of vegetation,soil and meteorology in previous years,analyzed the characteristics of community characteristics,soil physical and chemical properties and climatic factors in Kubuqi Desert.The relationship between vegetation and soil factors and climatic factors was discussed,which provided scientific basis for vegetation restoration and reconstruction in Kubuqi Desert.Research indicates:(1)Vegetation species increased from 8 families 16 genera and 19 species in 2007 to 11 families 26 genera and 34 species in 2016 in August,which included Compositae added 1 genera and 1 species,Polygonaceae added 1 genera and 4 species,Leguminosae added 2 genera and 2 species,Asclepiadaceae added 1 species,Labiatae added 1 genera and 1 species.as the same time,adding Euphorbiaceae and Caryophyllaceae in study area.The density of fixed and semi-fixed sand's Artemisia ordosica and flow sand's Artemisia blepharolepis decreased year by year.The density of Psammophytes,xerophytic,mesoxerophytes species is decreased,and even die in herb layer,but the density of mesophytes is increased.The biomass of different sandy land types increased year by year,the proportion of shrubs or semi-shrubs increased,and the proportion of herbaceous plants decreased.(2)The species diversity of fixed sand increased first and then increased,and the population remained the same.The species diversity and evenness of semi-fixed sandy land showed "W" type change.The species diversity and evenness of flowing sandy land showed "N" type change,and the overall increased.(3)The soil water content of different types of sandy increased with the year,the surface soil water content(0 ~ 30cm)increased,and the water content of deep layer(50 ~ 70cm)decreased obviously except 2010.Soil organic matter increased from 0 to 10 cm in fixed sandy land,soil organic matter decreased from 20 to 30 cm,while semi-fixed and flow sand was opposite to flowing sand.The surface soil total nitrogen(0 ~ 20cm)was significant decreased in fixed sand,and other levels were not significant.The soil total nitrogen in the upper and lower layers(0 ~ 30cm)in the semi-fixed sand and mobile sand was increased.Three kinds of sand soil total phosphorus change trend is consistent,which are all surface(0 ~ 20 cm)increases,the lower(20 ~ 50 cm)keep the same.Fixed and semi-fixed sand's soil total phosphorus(50 ~ 70 cm)increased significantly.(4)The organic matter,total nitrogen,total phosphorus,available potassium and available phosphorus in soil were closely related to the growth and distribution of plants,among which organic matter and total nitrogen played a major role;In the climate factor,the effect of precipitation on the biomass of vegetation is greater than relative humidity and atmospheric temperature,but it has not achieved significant effect.