Different Characteristics And Response To Soil Moisture With Salinity Gradient Of Phragmites Australis In Dunhuang Wetland

The response mechanism and adaptation strategy of plants to environment has been the focus of ecology research.Water and salinity are important limiting factors for the growth of plants in arid areas.They exhibit different morphological and physiological characteristics under different soil,water and salt conditions.This paper is based on the soil water and salt conditions Dunhuang sungate wetland nature background,mainly study the adaptability of stem-leaf on soil water and salt gradient,is of great significance for the protection of vegetation construction and the maintenance of biodiversity.This paper takes Dunhuang Yangguan Wetland depression pool area as the study area,along the direction of desert wetlands to set 5 transects,15 plots.With Phragmites australis as the research object,the determination of leaf number,leaf thickness,leaf weight ratio,leaf area,stem length,stem number,stem weight,leaf phosphorus content and leaf carbon content,leaf nitrogen content of 10 functional traits,and to investigate the content of soil water within each quadrat rate and salinity.By using system clustering,single factor variance analysis,Pearson correlation analysis and linear regression analysis method,and reveals the Dunhuang Yangguan wetland Phragmites australis stem leaf traits in different water and salt gradient and Phragmites australis functional traits on soil water and salt environment response.The result show:(1)There was a significant positive correlation between specific leaf weight and leaf number(r=0.902,p<0.01);leaf nitrogen content was positively correlated with leaf phosphorus content(r=0.604,p<0.01);stem length was significantly positively correlated with leaf number,specific leaf weight and stem diameter(p<0.01);specific leaf area was significantly negatively correlated with leaf number(r=-0.763,p<0.05),which was significantly negatively correlated with specific leaf weight(r=-0.786,p<0.01).(2)Compared with the increase of water content,the leaf thickness,specific leaf area,stem length and stem weight of Phragmites communis decreased significantly(p<0.05),but the leaf number and spcific leaf weight increased significantly(p<0.05).The leaf organic carbon content,nitrogen content and phosphorus content did not change significantly(p>0.05).(3)With the increase of salt content,the specific leaf area,stem length,stem number and stem weight of Phragmites australis increased significantly(p<0.05),while the leaf number and leaf weight decreased significantly(p<0.05).The leaf thickness,carbon content?nitrogen content?phosphorus content did not change significantly(p>0.05).(4)The synergistic effects of water and salt on the leaf thickness and stem length of Phragmites australis were significantly different(p<0.05).There were no significant effects on leaf number,specific leaf area,specific leaf weight,stem dry weight,leaf carbon,nitrogen and phosphorus content(p>0.05).The influence of soil moisture content on the stem leaf characters of Phragmites australis s was the most significant.Soil moisture is the main factor influencing Dunhuang sungate wetland reed leaf traits difference.