Revealing the Nexus Between Wind Wave Dynamics and Vegetation Biodiversity in Poyang Lake's Ecological Transition Zone

Abstract

Wind wave is a significant hydrodynamic factor in Poyang Lake, affecting the stability of the lake ecosystem. However, the processes and mechanisms by which it drives biodiversity patterns in ecological transition zones are not clear. This study delves into the intricate relationship between wind wave characteristics and the biodiversity of vegetation within the lake's ecological transition zone during the normal water level period from October to March in 2018–2019 and provides novel insights into the oscillation cycles of wind wave indexes and their influence on vegetation patterns. The main findings were as follows: (1) a cyclical trend occurred in wave height (WVH), wavelength (WVL) and shoreline flushing distance (FLD), with distinct oscillation periods and energy centres, notably a 47-day primary oscillation for WVH and WVL, and 40 days for FLD. It underscored the dynamic nature of wind wave interactions and their potential to shape the lake's ecological landscape. (2) Species richness increased from grasslands to ecological transition zones, dominated by Carex cinerascens, Phragmites communis and Triarrhena lutarioriparia, then declined towards water areas where Phalaris arundinacea and Gnaphalium affine became key species. (3) The biodiversity indexes (Shannon Diversity Index [SHDI], Modified Simpson Diversity Index [MSIDI]) and the evenness indexes (Shannon Evenness Index [SHEI], Modified Simpson Evenness Index [MSIEI]) reached the highest in the ecological transition zone and the lowest in the grassland, indicating the importance of these areas for species diversity. (4) There was a positive correlation between wind wave-induced shoreline flushing distance and vegetation height and coverage. This relationship was further linked to significant regulatory effects on vegetation richness, inversely affecting the size of vegetation diversity and evenness. Our findings highlight the complex trade-offs between vegetation richness and evenness/diversity, providing a foundation for future ecological restoration and conservation efforts. It not only contributes to the scientific understanding of the Poyang Lake ecosystem but also offers strategic insights for sustainable ecosystem management.