Combined influence of hydrological gradient and edaphic factors on the distribution of macrophyte communities in Dongting Lake wetlands, China

Hydrological regime and edaphic factors may operate synergistically to influence plant distribution in wetlands. However, this phenomenon has rarely been examined in freshwater lacustrine wetlands in China. Here, we investigated plant species compositions, hydrological gradients, and soil variables in four dominant plant communities and examined the relationships between plant communities and abiotic factors by using detrended canonical correspondence analysis (DCCA) in wetlands associated with Dongting Lake. The first and second axes of the DCCA ordination explained approximately 52.8 and 26.3 % of the total variance of the species-environment relationship, respectively. Water table depth was the strongest factor related to plant community composition and reflected the spatial distribution of vegetation in wetlands. Water-related soil variables (soil moisture content, bulk density, oxidation-reduction potential, and electrical conductivity) were significantly related to plant distribution. Soil nutrient factors (soil organic matter, total nitrogen, available potassium, and Olsen phosphorus) also played a role in plant distribution. Our findings emphasized the importance of hydrological gradients and related edaphic factors in determining the distribution of vegetation in freshwater wetlands. These findings have implications for conservation of freshwater lacustrine wetlands, which are often subjected to hydrological alteration and nutrient enrichment caused by anthropogenic disturbances and climate change.