EGU22-1737, updated on 27 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Hydrological drivers of the spatial distribution of herbaceous wetland communities at Poyang Lake

Wenqin Huang1,2, Tengfei Hu3, Jingqiao Mao2, Carsten Montzka1, Roland Bol1,4, Songxian Wan5, and Jin Yue6
Wenqin Huang et al.
  • 1Forschungszentrum Jülich, Institute of Bio- and Geosciences Agrosphere (IBG-3), Jülich, Germany (;;
  • 2College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China (;
  • 3Nanjing Hydraulic Research Institute, Nanjing, China (
  • 4School of Natural Sciences, Environment Centre Wales, Bangor University, Bangor, United Kingdom (
  • 5Nanji Wetland National Nature Reserve Agency, Nanchang, China (
  • 6School of Agriculture and Horticulture, Chengdu Agricultural College, Chengdu, China (

Hydrological processes are known as driving forces in structuring wetland plant communities, but still specific relationships are not always well understood. The dynamic, seasonally inundated wetland at Poyang Lake (less than 1000  km2 in the dry season and more than 3000 km2 in the wet season), the largest freshwater lake in China, underpinnes critical regional ecosystem services (e.g. flood water retention, water supply and biodiversity conservation). However, recent drier conditions of Poyang Lake are having a profound impact on its wetland vegetation leading to degradation of the entire wetland ecosystem, thereby also threatening the winter habitat of migratory birds. We aim to develop an integrated framework to quantitatively investigate the spatial distribution of major herbaceous communities that provide habitat for the migratory birds in response to Poyang Lake flood inundation. First, ground references are obtained from a combination of drone imagery and field surveys as an input for the wetland herbaceous community classification model. Our classification model is based on a machine learning technique applied to Sentinel-2 satellite data. This new search strategy provides an accurate classification based on the more optimal input variables and model parameters gained simultaneously. Secondly, based on the dynamic changes in water levels since 2000, we statistically evaluate the key environmental drivers of the hydrological regime on the spatial distribution of the wetland vegetation communities. This showed that: 1) different plant communities exhibited varying tolerance to flood inundation and 2) two key factors, i.e., average water depth and average duration of the inundation events, were found to be able to characterize the communities’ tolerance independently. For example, Carex cinerascens Ass. which had the widest inundation stress tolerance, being adapted to an inundation duration of 120~230 d and depth of 1.5~1.7 m, accounted for the largest herbaceous community (>27% cover) within the entire study area. Different survival strategies to inundation stress, such as dormancy and morphological restructuring, can explain the varying tolerance of plant species/communities. Our work elucidated the linkages between hydrological processes and herbaceous plants’ distribution in wetlands, and the approach can be readily applied at small to large catchment scales and provides a straightforward practical tool to predict the possible responses of the lake wetland vegetations to potential hydrological changes.

How to cite: Huang, W., Hu, T., Mao, J., Montzka, C., Bol, R., Wan, S., and Yue, J.: Hydrological drivers of the spatial distribution of herbaceous wetland communities at Poyang Lake, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1737,, 2022.