Distribution Pattern Of Main Plant Species In Desert Shrub Community In WEST Ordos

Taking the desert shrub in the western Ordos Reserve as the research object,this thesis uses the point pattern analysis method to study the spatial distribution pattern characteristics of the main dominant species in the desert shrub in this area,and further grasps the changes of environmental factors under the spatial distribution pattern of dominant species by analyzing the relationship between the spatial distribution of dominant species and environmental factors.The results showed that the spatial distribution pattern of the dominant species changed from uniform distribution to random distribution or aggregation distribution with the change of plot elevation.The negative spatial correlation between Zygophyllum xanthoxylon and Ammopiptanthus mongolicus indicates that there is competition between them.There is no spatial correlation between the two,which indicates that there is no competition between Zygophyllum xanthoxylon and Nitraria tangutorum.In plot A,B and C,overlord is negatively correlated with quadrangle space,and there is competition between Zygophyllum xanthoxylon and Tetraena mongolica.In plot D and E,there is no correlation with quadrangle space at large scale,and there is no competition between them.The study on water and soil nutrients showed that in the plots where Zygophyllum xanthoxylon and Ammopiptanthus mongolicus were the dominant species,Zygophyllum xanthoxylon and Ammopiptanthus mongolicus mainly used soil water within the range of 40-60 cm.The contribution rate of water use depth of Zygophyllum xanthoxylon tended to be stable on the whole,with an average contribution rate of 31.91%,but the water absorption level changed.They prefer to use soil moisture within the 40-60 cm range,and there is water competition between the two plants.In the plots dominated by Zygophyllum xanthoxylon and Nitraria tangutorum,Nitraria tangutorum mainly used 0-20 cm soil water,Zygophyllum xanthoxylon mainly used 20-40 cm soil water,indicating that there was no competition between Zygophyllum xanthoxylon and Nitraria tangutorum in water use.The vertical distribution and stoichiometric characteristics of soil organic carbon,N and P contents in the study area were studied.The results showed that with the increase of elevation,the contents of total nitrogen and total potassium of dominant species in the plot were almost not significant,only the content of organic matter changed,and the difference was significant.According to the difference analysis of soil nutrients between plants and open space in different areas,it was found that the content of organic matter between plants and open space was significantly different,while the difference of other soil nutrients was not significant,indicating that the content of soil nutrients was similar under different vegetation types in the study area.