【Objective】 A wetland with a large reed area exists in West Lake, Dunhuang, Gansu Province in the extremely arid region of Northwest China; however, artificial and natural interference have caused environmental conditions to decline in this region. The aim of this study is to understand the niche characteristics of the plant community and its succession trends in the degraded saline reed meadow, as this will provide important information for the restoration and management of salinized Phragmites communis.【Method】A field investigation was conducted in West Lake, Dunhuang in early September 2017. The center of the field was in the lowest region of Yanchiwan(elevation 997 m). Two sample belts were placed at right angles to each other in west-east and south-north directions. Five fixed plots(30 m ×30 m)were positioned in each sample belt and plots were 100 m apart. Five small plots(5 m×5 m)were randomly selected along two diagonals in the sample plot. Plant species, height, abundance, coverage, and density were recorded in 50 small plots. Niche characteristics of the reed salt meadow were examined using Levins niche breadth index and Panika niche overlap index based on the results of the field investigation.【Result】Nine species of plants(belonging to six families and nine genera)occurred in 10 plots, including super-xerophytic, halophytic, sandy, wet and aquatic plants. Phragmites communis was the dominant species in the salinized meadow community, and its spatial distribution was characterized by the coexistence and transition between desert and wetland types. The niche breadth order was: Phragmites communis (0.350), Alhagi sparsifolia (0.263), Carex orbicularis(0.185), Glycyrrhiza inflate(0.184), Leymus secalinus (0.184), Salsola collina (0.145), Apocynum venetum (0.117), Lycium ruthenicum (0.115), and Glaux maritima (0.059). Niche overlap(Okj)ranged from 0.505 to 0.995. The Okj of 19 pairs of populations were greater than 0.7, 15 pairs were greater than 0.8, and 9 pairs were greater than 0.9, accounting for 53%, 42% and 25% of the total, respectively. Overall, there was a high level of niche overlap among species. Results show that there was high similarity in resource utilization among plant populations in the reed saline meadow in Dunhuang West Lake.【Conclusion】The reed saline meadow community in Dunhuang West Lake consisted of desert vegetation and wetland vegetation, and its spatial distribution was characterized by the coexistence and transition between desert and wetland types. The maximum niche overlap index of reed saline meadow was accompanied by the maximum niche width between dominant species. Otherwise, niche differentiation between groups was not obvious. In particular, strong competition was observed between Phragmites communis and Alhagi sparsifolia, indicating that if environmental conditions decline and groundwater levels decrease, the saline meadow that is currently dominated by Phragmites communis will be succeeded by desert vegetation(primarily Alhagi sparsifolia).
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