Study On The Functional Diversity Of Plant Communities On Different Slopes In The Alpine Meadow Of Gannan

The relationship between plants and the environment is one of the emphases of ecological research.The functional diversity based on plant traits is an important component in the study of ecosystem function.The study of plant character and functional diversity is of great significance to the study of community composition and the maintenance of ecosystem structure and function.This paper takes alpine meadow plant community as the research object,selects 8 functional traits of plants,calculates them by community weighted average value?CWM?,calculates species diversity and functional diversity,and explores the changes of environmental factors,species diversity,functional traits and functional diversity in different slope direction.The main results of this study are as follows:?1?Environmental factorsThe minimum value of the variation of illumination?LI?days appeared in the west slope at 7:00,and the maximum value appeared in the south slope at 13:00.The maximum value of diurnal variation of soil temperature?ST?appeared in the south slope at 14:00 and the minimum value appeared in the west slope at 7:00.On the south-north slope gradient,the soil water content?SWC?decreased gradually from north slope to south slope.Soil pH is highest in south slope and lowest in north slope.The slope gradient?SG?increases obviously from north slope to south slope with the change of slope direction.Soil organic carbon?SOC?,soil total nitrogen?STN?and soil total phosphorus?STP?all decreased first and then increased as the slope went from north slope to south slope,with the north slope and northwest slope reaching the highest and the west slope the lowest.?2?species diversityIn gannan alpine meadow on the south-north slope to the gradient,Richness index,Margalef index,Simpson index,Shannon index and Pielou index change tendency is consistent,both from the north to the south slope is decreasing gradually,among them,the Richness index,Margalef index,Simpson index,Shannon index in each of the slope to the differences between the significant?P<0.05?,Pielou index between the slope to the difference was not significant.?3?Functional traits of plant communityPlant height(PH_CWM),Leaf water content(LWC_CWM),Specific leaf area(SLA_CWM),Leaf carbon content(LCC_CWM),Leaf nitrogen content?LNC?,Leaf phosphorus content(LPC_CWM),Leaf kalium content(LKC_CWM)decreased successively from the north slope to the south slope.The minimum values of PH_CWM,LWC_CWM,SLA_CWM,LPC_CWM,LKC_CWMWM all appeared on the south slope,while the minimum values of LNC_CWMWM appeared on the west slope.Negative correlation with ST,soil pH,SG and LI?P<0.05?;Leaf dry matter content(LDMC_CWM)increases successively from the north slope to the south slope with the change of slope direction.The maximum and minimum values appear in the south slope and the north slope,and are negatively correlated with SWC,STP,SOC and STN?P<0.05?,and positively correlated with ST,soil pH,SG and LI?P<0.05?.?4?Functional diversity of one-dimensional traits in plant communitiesThe functional diversity of plant height(PH_FDrao)of the north slope was significantly higher than that of the south slope and the southwest slope.Functional diversity of leaf water content(LWC_FDrao)was the highest in the northwest slope and the lowest in the south slope.The maximum and minimum values of functional diversity of specific leaf area(SLA_FDrao)appear in the northwest slope and the southwest slope respectively.Functional diversity of leaf dry matter content(LDMC_FDrao)decreases gradually from south slope to north slope.Functional diversity of leaf carbon content(LCC_FDrao)decreases from northwest slope to south slope.The maximum value of functional diversity of leaf nitrogen content(LNC_FDrao)appeared in the north slope,and the minimum value appeared in the west slope.Functional diversity of leaf phosphorus content(LPC_FDrao)showed an increasing trend from the south slope to the north slope.The functional diversity of leaf kalium content(LKC_FDrao)on the north slope is significantly higher than other slope directions.LDMC_FDraoDrao was positively correlated with pH,SG,ST and LI?P<0.05?,and negatively correlated with SWC,STP,SOC and STN?P<0.05?.PH_FDrao,LWC_FDrao,SLA_FDrao,LCC_FDrao,LNC_FDrao,LPC_FDraoDrao and LKC_FDraoDrao were negatively correlated with pH,SG,ST and LI?P<0.05?,and positively correlated with SWC,STP,SOC and STN?P<0.05?.?5?Functional diversity of multi-dimensional traits in plant communitiesFunction richness?FRic?and function dispersion?FDis?of multi-dimensional traits decreased gradually from north slope to south slope,with significant difference between slope directions?P<0.05?.Functional evenness?FEve?is the highest in the southwest slope and the lowest in the north slope,but the difference between the slope directions is not significant.Richness index,Margalef index,Simpson index,Shannon index and Pielou index and functional Richness?FRic?,the function dispersion?FDis?were positively correlated?P<0.05?,and negatively correlated with functional evenness?FEve??P<0.05?.This study illustrates the influence gannan alpine meadow plant community species distribution of the main environmental factors and plant community species diversity,function characteristics,functional diversity along the slope to the change of gradient,this to further understand the mechanism of plant community building,biodiversity and ecosystem function link has an important meaning,at the same time for the degraded alpine meadow pasture restoration,soil and water conservation,ecological function optimization,and build a more balanced and orderly ecosystem to provide reference and scientific basis.