Relationship Between Plant Diversity And Productivity Of Gentianella Turkestanorum Adaptive Communities In Bayinbulak Mountains Of Xinjiang

Relationship between plant diversity and productivity at different altitudes is a hot topic in ecology.Species diversity can reflect community stability;Functional diversity can reflect the adaptation strategy of community to environment.Aboveground biomass can directly reflect community productivity and predict ecosystem function.However,there is no definite conclusion on the relationship between the three factors under different environmental factors.Gentianella turkestanorum is one of the important folk medicine resources,which is widely distributed and occupies an important ecological niche in Bayanbulak District of Xinjiang.There are few reports on the ecological characteristics of Gentianella turkestanorum in this area.Exploring the relationship between plant diversity and productivity can not only enrich the theoretical content of the relationship between plant diversity and productivity,but also provide a theoretical basis for the protection of ecosystem stability in Bayanbulak grassland,and effectively promote the rational development and utilization of Gentianella turkestanorum resources.This study on the brook mountain under different altitude gradient in the suitable plant community of Gentianella turkestanorum as the research object,through the wild plant community sample plot survey,combined with the indoor soil sample index determination,using the method of correlation,regression and significant differences with the RDA sorting method,analyzed the different altitude gradient of Gentianella turkestanorum plant community in the suitable area diversity and aboveground biomass and distribution characteristics of environmental factors and their mutual relationship,the results were as follows:(1)on the brooke mountain at an altitude of 2400-3000 m range set of 18 samples of the communist party of China record to 52 species,belonging to 35 genera and 20 families,among them,the monocotyledon 27 genera,10 species,28 genera,18 families of 42 kinds of dicotyledonous plants,according to the important value and the vegetation and its utilization in xinjiang will sample plots of plant community was divided into six plant community types.(2)The species diversity of Gentianella turkestanorum plant community in the suitable area was significantly different at different altitudes.Shannon diversity index showed a "unimodal" trend with increasing altitude,and reached the peak value at 2590.2 m.Species richness index and evenness index decreased significantly,and there was a significant negative correlation between them.(3)The functional traits and functional diversity of Gentianella turkestanorum plant community in the suitable area showed a significant trend under different altitudinal gradients.Among them,plant height,leaf area,leaf area,leaf dry weight,leaf dry matter content and leaf carbon content showed a "single peak" pattern with the increase of altitude,and the peak values were at 2590.2,2754.1,2612.6,2817.5,2590.2 and 2817.5 m,respectively.While leaf nitrogen and phosphorus contents showed a significant increase trend.The functional richness index,quadratic entropy index and functional dispersion index showed a significant change pattern of decreasing,increasing and "unimodal" with increasing altitude,respectively,and there was a significant correlation.(4)According to the energy function group,the suitable plant community of Gentianella turkestanorum was divided into sedges,grasses,legumes and mixed grasses.Aboveground biomass of sedge plants increased significantly with elevation.Aboveground biomass of Gentianella turkestanorum,grasses,legumes,mixed grasses and total communities showed a "single peak" pattern,with the highest biomass at 2612.6,2612.6,2754.1 and 2754.1 m,respectively.(5)There was a correlation between plant diversity and aboveground biomass of Gentianella turkestanorum plant community in the suitable area.Among them,the increase of aboveground biomass of sedge and grasses decreased species richness,leading to the convergence of functional traits and the decrease of functional diversity.Species evenness had a negative effect on functional richness and was also negatively correlated with aboveground biomass of sedge plants.(6)Under different elevation gradients,the contents of soil factors were also different.Among them,the increase of nitrogen would promote the evenness of species distribution and functional diversity,and would increase the biomass of Gentianella turkestanorum and hybrid grasses,but would lead to the decrease of aboveground biomass of sedges and grasses.Phosphorus could promote the biomass increase of Gentianella turkestanorum and hybrid grassland,and then could increase the total biomass of species.Salt and available potassium also promoted the aboveground biomass of Gentianella turkestanorum.In conclusion,the correlation between plant diversity and aboveground biomass of species and environmental factors is mainly due to the different changes of temperature,precipitation,soil chemical elements and human disturbance at different elevation gradients.Therefore,Gentianella turkestanorum plant community in the suitable area showed significant differences in plant diversity and aboveground biomass,and then changed the relationship between plant diversity and productivity.