Researchers from the Chinese Academy of Sciences have made new progress in the study of the spatial distribution pattern of biomass above ground of herbaceous swamp vegetation in China

In the context of global change, the study of wetland carbon sequestration has become one of the important contents of global carbon cycle research. China's swamp wetlands are ranked third in the world in terms of area, with herbaceous swamps being the most widely distributed and have a higher rate of carbon sequestration. As one of the important quality parameters of swamp wetlands, aboveground biomass of vegetation is an important indicator for estimating the vegetation carbon storage of swamp wetlands, and it is also the basis for studying carbon sequestration in swamp wetlands. At present, many scholars have studied the biomass of herbaceous swamp vegetation in China at the local or regional scale, but the aboveground biomass and spatial distribution pattern of herbaceous swamp vegetation at the national scale are not clear.

With the support of the Ministry of Science and Technology's National Science and Technology Basic Work Special Project "Comprehensive Survey of China's Swamp Wetland Resources and Their Main Ecological And Environmental Benefits", led by the Northeast Institute of Geography and Agroecology of the Chinese Academy of Sciences, more than 100 scientific researchers from 12 units such as Northeast Normal University and Beijing Forestry University conducted a comprehensive survey of China's swamp wetland resources. The survey covered the plant, water and peat resources and ecological benefits of 440 swampy wetlands across the country, and a total of 18,390 sample surveys were set up.

The survey results show that, first, the aboveground biomass density of Herbaceous swamp vegetation in China shows the characteristics of low in the northeast and Qinghai-Tibet Plateau regions, and high in central China and coastal areas. Second, the spatial distribution of above-ground biomass in Chinese herbaceous swamp vegetation has obvious non-zonal characteristics, but it also shows a certain zonal law in some areas. In the subtropical wet swamp area and the coastal swamp area, there is no obvious correlation between vegetation aboveground biomass and hydrothermal conditions and altitude, which may be due to the better hydrothermal conditions and suitable vegetation growth in the subtropical humid semi-humid area and the coastal swamp area, and the hydrothermal conditions are not the limiting factors for the growth of swamp vegetation, resulting in more obvious non-zonal characteristics of herbaceous swamp plants in these areas. With the increase of altitude, the temperature decreases, the environment becomes harsher, the resource effectiveness decreases, and the ability of plants to obtain maximum photosynthetic energy decreases, resulting in small aboveground biomass of vegetation in high-altitude areas. In temperate arid and semi-arid regions and temperate humid semi-humid areas, with the increase of drought, the aboveground biomass density of herbaceous swamp vegetation decreases first and then tends to flatten, and in temperate humid semi-humid areas, the aboveground biomass of herbaceous swamp vegetation is relatively larger in areas with higher annual average temperature.

This study clarifies the spatial distribution pattern of aboveground biomass in Chinese herbaceous swamp vegetation, and provides a scientific basis for accurately assessing the carbon sequestration potential of China's marsh wetlands and formulating adaptive management strategies for swamp wetlands. (Meng Hanqi)

Source: Xinhua News Agency