Study On The Seed Bank Of Prunus Mongolica Maxim At The Different Elevation

Prunus mongolica Maxim is the specific xerophilous and deciduous shrub of the gobi desert region. It is landscape and soil-conserving plant of desert region and desert steppe,also be an important woody yushina plant. It is determined as the plant of the third-class protection.This article analyzed the community characteristics of Prunus mongolica Maxim at different elevation, seed rain and seed bank of Prunus mongolica Maxim , soil properties as well as the seedling growth which takes the natural Prunus mongolica Maxim of baotou lugou area as research object and uses plant population ecology as the research method, The results were shown as follows:1. Prunus mongolica Maxim plant community,which floristic composition is quite poverty and has obvious important family, floristic composition mainly contain gramineae, compositae, rosaceae and leguminosae plant of Angiosperms, structure structural hierarchy of vegetation community is single in Baotou lugou area,There was a negative correlation between Community species richness and altitude. Through the comparison of index ofβ-diversity, with altitude increased, Similarity decreases, species replacement increased, The diversity of communities has a certain change law. Difference becomes not obvious on Biological Diversity in Adjacent elevation condition. Species replacement becomes slow.2. Plant water ecotype of Prunus mongolica Maxim community in Baotou lugou, hemicryptophyte has a high proportion of Living Type,The relationship between the vegetation and environmental condition such as local summer strong light, high temperature, evaporation over precipitation, longer and cold winter is reflect clearly.3. The damage fruit of Prunus mongolica Maxim left by animal nibbled in the rain has a proportion of 23.4%, it is adverse to seedlings renewal of Prunus mongolica Maxim population,this indicates the effect on feeding stress that Prunus mongolica Maxim nibbled by animals in the process of Prunus mongolica Maxim population renewal part can not be ignored. With altitude increased, Prunus mongolica Maxim seed rain density showed a decreasing trend. The temporal pattern of Prunus mongolica Maxim seed rain density exhibits no significant difference between July 2007 and July 2008. In spatial distribution aspect, Prunus mongolica Maxim seed scattered in the section of 0~80 centimeter and take for mother plant as the center, the most dense section of the distribution is 15~80 centimeter to the distance of mother plant,little seeds can scatter beyond 1.5 meter by their self-action because of their large seeds. In Prunus mongolica Maxim seed bank, the vertical distribution of Prunus mongolica Maxim seeds mainly concentrated in the litter layer. The horizontal distribution of seeds mainly distribute in the range of 2 meter that distance to the shrub center. The amount of seed that outside the shrub decreased significantly.Finally, shown a trend that seeds have a sharp downward from shrub center to shrub outside.4. The soil of each elevation is in the scope of the depth of 0~30 cm. With the deepening of the depth of soil, Soil water content gradually increased. The general trend of the soil water content in the same soil layer at different elevation is increased at first then decreased. The difference of soil water content between the same soil layer at different elevation is not distinct. The general trend of the soil organic and total phosphorus is not obvious.The generall trend of the total nitrogen content is first increased then decreased. In the same soil layer at different elevation is increased at first then decreased. With the increasing of the altitude, the content of soil orgnic and total phosphorus in the Prunus mongolica Maxim community is presented to be decreased gradually in the same soil layer at different elevation. The generall trend of the total nitrogen content is first increased then decreased.5. With the increasing of the altitude, The C content, the N content and the P content in the blades of Prunus mongolica Maxim at different altitude is showing a declining trend and N / P ratio is gradually increasing.6. The seeds diposed by six kinds of different soil water content all can germinate, With the increasing of soil water content, the germination rate of the Prunus mongolica Maxim seed is showing a trend of first increasing then decreacing. Soil water content has a significant influence on the biomass of young Prunus mongolica Maxim. 8% soil water content are most conducive to the young Prunus mongolica Maxim biomass accumulation, the soil water content is too high (≥12%) or too low (≤2%) are both not conducive to the growth of the young Prunus mongolica Maximm. According to correlation analysis, we can find that the soil water content has close correlation with the seed germination rate, germination index and bioss. Ratio of root to shoot is closely related to the germination rate, germination index,bioss and ratio of root to shoot. The soil water content is one of the important factors which impact the seed germinate and the growth of young Prunus mongolica Maxim.