Study On The Community Diversity And Population Spatial Pattern Of Salsola Passerina In The Desert Area Of Inner Mongolia

As a world environmental problem,land desertification has threatened the sustainable development of human beings.Land desertification has destroyed the natural environment and biodiversity.To prevent and control land desertification and protect ecological environment are the primary problems of economic construction in Inner Mongolia desert area.Salsola passerina is an important dominant species or constructive species in Inner Mongolia desert area,which has strong tolerance to arid and barren habitats.Salsola passerina community is also a very important grassland type in desert area,and has important value for ecological construction in desert area.In this paper,the species composition,structural characteristics,quantitative characteristics,species diversity and their relationship with environmental factors of 10 Salsola passerina communities in different habitats in desert area of Inner Mongolia were studied,and the spatial distribution pattern of Salsola passerina population was analyzed.In order to study the spatial distribution pattern of other plant populations and provide suggestions for the protection and tending of Salsola passerina population.The results show that:1)There are 35 species of angiosperms,belonging to 12 families and28 genera in the community.Most of the species in the community are Chenopodiaceae,Zygophyllaceae,and Gramineae.Shrub and subshrubs were the main life forms in Salsola passerina community.There are 8shrubs,6 subshrubs,12 perennial herbs and 9 annual herbs.The functional structure and stability of Salsola passerina community in Inner Mongolia desert are mainly determined by shrub and subshrub layers.The density,biomass,coverage of Salsola passerina community showed a decreasing trend with the decrease of annual rainfall.Salsola passerina community is often composed of Reaumuria songarica,Nitraria sphaerocarpa,Potaninia mongolica,Cleistogenes songorica,Allium polyrhizum and so on.2)The community survey results were analyzed using four diversity indexes,and the correlation analysis with environmental factors showed that the community diversity level of Salsola passerina in the desert area of Inner Mongolia is low,there are significant differences between the plots due to the different effects of climate,soil and other factors.The diversity index is greatly affected by the herb layer.Margarlef index had a extremely significant negative correlation with altitude;The Margarlef index has a extremely significant positive correlation with temperature ecological factors such as the annual average temperature,the highest temperature of the hottest month,and the average temperature of the driest season;Margarlef index had a significant negative correlation with soil total nitrogen,0-10 cm soil available nitrogen and 20-30 cm soil organic matter Shannon-Wiener index was positively correlated with the lowest temperature in the coldest month and the average temperature in the coldest quarter;Shannon-Wiener index had a significant positive correlation with soil p H.Simpson index had a significant positive correlation with longitude position.The correlation between the uniformity index of Pielou and soil moisture content was significant.Climate and soil factors work together to affect the diversity of the Salsola passerina community in the desert area of Inner Mongolia.3)The population density and coverage of Salsola passerina decreased with the decrease of precipitation in desert area of Inner Mongolia.Salsola passerina populations are mainly stable populations and growth populations.The proportion of grade 2 plants is generally higher,and the population of Salsola passerina is relatively stable.When the habitat of Salsola passerina population is relatively humid,the spatial distribution pattern is more complicated,and the distribution tends to be random as the degree of drought increases.In a relatively humid environment,the population spatial pattern of the 1st and 2nd grade plants is more complicated.As the degree of drought increases,the population spatial pattern tends to be randomly distributed.Grade 3plants showed a clustered distribution at the mesoscale in some plots,and the others were randomly distributed.Most of the age classes of the Salsola passerina populations show positive or negative correlations on a small scale,except for some age classes that have negative correlations on medium to high scales,and the populations tend to be unrelated.The population of Salsola passerina has a high adaptability to the arid and harsh environment in Inner Mongolia desert.The low species diversity of Salsola passerina community in Inner Mongolia desert area is related to the arid and barren habitat.The protection of the Salsola passerina community should focus on the improvement of the microenvironment and increase the water conservation in the habitat.It can reduce human disturbance and grazing,maintain population regeneration and promote the stable development of ecosystem.