Research On Plant Diversity In Xilingol National Nature Reserve

Irrational grazing is the main cause of the degradation of typical grasslands in Inner Mongolia.Irrational grazing practices have led to the loss of grassland plant diversity,a drastic reduction in vegetation area,and an increase in endangered species or even their extinction,so how to use grasslands rationally has become one of the main elements of research by scholars.The Xilingol National Nature Reserve,located in the typical grassland area of Xilingol,has played an important role in improving the regional ecological environment,maintaining soil and water,nourishing water and protecting biodiversity.The three different functional zones(core zone,buffer zone and experimental zone)of the reserve represent three types of anthropogenic disturbance and intensity and provide an ideal research site for this thesis.This thesis uses the vegetation of the Xilingol National Nature Reserve as the object of study,and obtained various plant community indicators in the core,buffer and experimental zones through field surveys.We measured and calculated the functional traits CWM,above-ground biomass,species diversity indicators and functional diversity indicators of the plant community,and analyzed the differences between the three functional zones and the one-dimensional linear relationships between these indicators.The main findings of the study are as follows:(1)The high intensity of grassland use in the experimental area has resulted in the degradation of typical grasslands,which have a high distribution of shrubs,semi-shrubs and 2012 herbs,which are gradually replacing perennial herbs.A core area free of human disturbance(fenced-in)had a significant positive effect on the biomass,plant height and density of the typical grassland plant community.In contrast,grazing use has a significant negative effect on plant height,density,total cover and biomass with increasing grazing intensity.the buffer zone(moderate disturbance)has able to increase the total plant cover of the grassland,which significantly increased species richness,the species dominance index and the Rao quadratic entropy index.The results indicate that fencing and culturing(core zone)is significantly effective in protecting plant communities,but moderate disturbance is conducive to solving problems such as sustainable development of grassland and loss of plant diversity.(2)Different functional areas had significant effects on the functional traits of typical grassland plants.Both shoot position and leaf area were significantly increased in the buffer zone(p<0.05);long-term fencing in the core zone promoted plant root growth,so the root depth of plants in the core zone was significantly higher than that in the buffer and experimental zones(p<0.05).(3)The Shannon-Weiner index was strongly correlated with the functional richness index(FRic)and the functional evenness index(FEve),and the correlation between species richness and the functional richness index(FRic)and the functional dispersion index(FDiv)was strong and showed positive correlations.(4)Different functional areas had a significant effect on the regression relationship between plant diversity and above-ground biomass in typical grasslands.The positive correlation between species richness and above-ground biomass in the core area(p<0.05)and the negative correlation between species richness and above-ground biomass in the buffer and experimental areas(p<0.05)indicate that disturbance can increase species diversity in grassland,but it is difficult to maintain high productivity in grassland even if species diversity increases in the presence of disturbance.In contrast,the higher the species diversity in the undisturbed core area,the higher the productivity.(5)Integrating community characteristics,plant functional traits and grassland community productivity,the core zone is effective in conserving plant diversity and maintaining grassland productivity under different functional zone utilization patterns of typical grasslands in Xilingol National Nature Reserve,while moderate disturbance and utilization are more important for maintaining species diversity in grassland ecosystems.The present study suggests that a moderately disturbed buffer zone is more conducive to the restoration of grassland vegetation and the stability of the ecosystem,and is important for the conservation of grassland plant diversity in the region.