Modeling plant species-abundance distribution patterns with elevation in typical marshland communities of the Poyang Lake region

Plants were surveyed in four sites using 19 quadrat plots (5 m×5 m) at different elevations (high elevation-lakeside,medium elevation-center of marshland,edge of marshland) in the Chayegang marshland of Henghu farm,China.Four niche models were employed to simulate plant species-abundance distribution patterns along elevation gradients.Results showed that:(1) The number of occasional species declined gradually with decreasing elevation,with average coverage persistently becoming lower;whereas,the number of common species remained unchanged and average coverage and height of the dominant species Carex cinerascens Kukenth steadily increased,thus occupying a more dominant position in the community;(2) The species-abundance distribution patterns over the whole high elevation,medium elevation,and low elevation areas were best fitted by the niche preemption model (P < 0.05;AIC values were-149.41,-61.11,and-25.63,respectively);whereas,the broken stick model,overlapping niche model,and dominance preemption model showed poor fitting along the elevation gradient in general (P < 0.05;AIC values were all larger).These results should provide useful information for the protection of biodiversity and exploration of the constructive mechanisms of plant communities.