Abstract:

Wetlands possess some of the highest carbon densities among ecosystems. Understanding the dynamics and growth trends of wetland vegetation biomass is crucial for achieving the carbon peaking and carbon neutrality goals. Based on LandSat remote sensing images, we estimated the aboveground vegetation biomass in Poyang Lake wetland during spring and autumn between 2000 and 2020, and examined its development trend in different growing seasons and hotspot areas. The findings revealed that: 1) In recent two decades, aboveground vegetation biomass in spring ranged from 0.85×10⁹ to 4.20×10⁹ g, while in autumn from 0.68×10⁹to 6.69×10⁹ g. Spring biomass remained stable, whereas autumn biomass exhibited a consistent increase over time. 2) Hotspot areas for aboveground vegetation biomass in spring and autumn covered 754.15 km² and 1 085.49 km², respectively, representing 21.58% and 30.66% of the total wetland area. 3) Spring and autumn biomass showed a positive correlation with monthly mean temperature. The vegetation in Poyang Lake wetland serves as a robust carbon sink, aiding in the pursuit of carbon peaking and carbon neutrality.

Key words: plant biomass, remote sensing retrieval, temporal-spatial distribution, hotspot area, Poyang Lake