Distribution And Impact Mechanism Of Artemisia Scoparia Along The Sandy Patch Interface

The desert steppe is the most arid type of grassland,belonging to a kind of natural.Under the influence of human activities and natural disturbance,the natural landscape of large continuous distribution is separated into many smaller habitat patches by other unsuitable habitats,which leads to the fragmentation and separation of the patches,which is complicated by the simple trend.In the broken patches,the position of Artemisia annua L.plays an important role in grassland quality.In this paper,the distribution characteristics of soil and vegetation in a typical "sand cover erosion" transitional zone in the southern edge of Maowusu sandy land were studied by means of field transect survey and laboratory analysis.The main conclusions are as follows:1)Most of the plants in the sandy soil interface are Gramineae,Leguminosae and compositae.There are 28 species of plants belonging to 12 families and 27 genera in the field nvestigation.The dominant species of perennial herbs are Gramineae,Leguminosae and compositae.Dominant position of Stipa grandis and Artemisia annua in community.The species richness of desert steppe was the highest in the interface,which is the result of the interaction of sand soil patches.2)There was an interface change between the community characteristics and soil factorsThe interface of Artemisia scoparia community with average height,coverage,biomass,density,species richness,Shannon Wiener index,evenness index,dominance index with transect extending change.There are a large number of plants in the desert steppe,such as Stipa,and so on,which leads to the low correlation between community density and biomass.Soil moisture,nutrients and particle size also showed a gradient change with the sample,reflecting the interface effect,and there is a strong spatial autocorrelation.3)Determining the community diversity and functional groups of Artemisia annua L.The application of redundancy analysis(redundancy analysis RDA)on Stipa Artemisia scoparia community transition in the space of the vegetation and soil factors of continuous change,and the relationship between vegetation distribution and diversity and the main factor of soil between.The results showed that the main soil environmental factors that affected the distribution and species diversity of Stipa grandis,Artemisia annua L.,were 20-40cm and 20-40cm.The main soil environmental factors which had significant influence on vegetation functional groups were 20-40cm coarse sand and 10-20cm total phosphorus,respectively.There was significant correlation between the changes of soil nutrients and quality in the current plant distribution pattern,but the amount was not high.The spatial pattern of species dispersal competition under the constraint of 20-40cm soil particle size.The diversity of plant community decreased with the increase of soil particle size,and the distribution of plant was more compact and small.4)Ddesert grassland sandy soil interface is easy to wind erosion,resulting in reduced grassland quality.Correlation comparison of three soil factors and the community can be found:the soil organic carbon and biomass showed a significant correlation,and the correlation from the surface to the deep decline,the reason is one of the organic carbon is the main source of plant litter decomposition,distribution with depth of litter decomposition and the fewer opportunities,which consistent with Qiu Kaiyang 'research results;and the correlation between total nitrogen and biomass showed no significant correlation to the surface,10-20cm,20-40cm layer correlation obviously,the reason may be the obvious effect of nitrogen leaching.Correlation between water content and community coverage,biomass,density analysis shows that:the surface soil due to much interference,the correlation is not obvious,and 20-40cm layer soil moisture content and community coverage and biomass and density were significantly correlated,significant correlation,so it can be conclude that the underlying strata water content decision the distribution characteristics of the community to a certain extent.Found the correlation of different soil particle content and community coverage and biomass:unlike organic carbon,soil particle size and the correlation of coverage biomass was not significant,but more significantly more to the bottom,0-10cm sticky powder with significant coverage and biomass between 20-40cm and clay particle coverage and biomass were significant positive correlation was not significant;0-10cm coarse sand and coverage and biomass correlation,20-40cm and coarse sand cover and biomass was negatively correlated,is due to a high content of coarse sand soil granular structure of soil loss,soil porosity,permeability resistance increases,resulting in loss of water increases,the limits of the species into.It can be seen that the correlation between the underlying strata or the parent material and the community is more obvious.Therefore,the bottom soil texture is the main factor to determine the construction of rtemisia annua community in the desert steppe area.