Species Diversity And Water Use Relationships Of Riparian Plants In The Lower Reches Of Heihe River

In this paper,we use China’s second largest desert riparian forest vegetation of continental river downstream of heihe river as an example.The use of stable isotopes from the Angle of water source community focused on community within the moisture of synergetic competition relationship between different species,and by using the survey data analysis of species diversity and stability,in order to further reveal the diversity(water use relationship)provide evidence and the relationship between the community stability,aimed at the lower reaches of heihe river ecological water allocation scheme and the recovery of desert riparian forest,provide a scientific basis for protection.The results showed that:(1) Different kinds of plant xylem delta D,18 O delta value is different,show that different kinds of plants in different water depth,The Populus euphratica(seedlings),which make use of 0-20 cm of soil water,The Tamarix ramosissima mainly absorbs 200-300 cm deep soil water,The Prunus spinosa mainly use 0-20 cm of soil water,The Karelinia caspia mainly use 50-100 cm of soil water,The Peganum harmala mainly use 0-20 cm of soil water,and The Sophora alopecuroides mainly use 0-5 cm of soil water.The contribution rate of different potential water on the plants in different plant species varies,herbaceous plants mainly uses shallow soil water,shrubs because of different plant species,there are differences between the source of water,and trees Populus euphratica(seedlings),which make use of shallow soil water;(2) Based on the experimental result,there are competition relations among Heihe River Populus euphratica with Prunus spinosa and Peganum harmala in water use,The Populus euphratica and Tamarix ramosissima may help other species in water use.(3) From the perspective of the number of features of diversity index,Simpson,diversity index,change the range of 0-0.73;Margalef abundance index of the range of 0-1.0;Pielou evenness index range 0-0.86,suggests that community structure is simple,and the level of community species diversity is low;(4) Using the improved M.Godron stability determination method of community stability,and results show that the stability of each sample plot ratio is different;The more abundant species diversity,the more complex relationships between species,and the the community is greater stable,but it also lack strong evidence,needs further research.