Aboveground biomass and the spatial distribution pattern of herbaceous marsh vegetation

Credit: CC0 Public DomainThe three largest ecosystems worldwide are ocean, forest, and wetland. The area of the wetland ecosystem is only 46% of the land surface, but the carbon reserves from the wetland ecosystem account for 12-24% to the global land carbon resources. Global climate change has made carbon sequestration research an important topic in global carbon cycle research.China's marsh area ranks third worldwide, with herbaceous marsh being the most widespread of all types of marshes. Aboveground biomass is an important quality parameter for marsh ecosystems. It can be used to estimate the carbon storage in marsh vegetation and also serves as the basis for studying carbon sequestration. While many researchers have examined the biomass of herbaceous marl in China's local and regional areas, it is unclear what the national aboveground biomass of herbaceous marl is.More than 100 scientists from 12 institutions conducted a systematic investigation of wetland resources in China with the help of the National Science & Technology Fundamental Resources Investigation Program of China. The survey included 18390 quadrats who surveyed the ecological, plant and water conditions in 440 Chinese wetland areas. To obtain the most comprehensive and complete data on herbaceous marsh vegetation in China, aboveground biomass was measured. This survey provided a comprehensive overview of the marsh wetland situation and a key dataset to support the protection and scientific management marsh wetland. Jiang Ming stated that the large-scale survey data provided information about the aboveground biomass, as well as the spatial distribution patterns of herbaceous marsh vegetation in China.These results revealed that China's total area of herbaceous marl was 9.7 104 km2. The average aboveground biomass density for China's herbaceous mammal vegetation was 227.5 g C/m2. The total aboveground biomass for herbaceous marsh vegetation was therefore approximately 22.2 TgC.The aboveground biomass density for herbaceous marsh in China is 12 to 1400g C m-2. There are low biomass areas in Northeast China and Tibet Plateau. However, there is high biomass in the central North China coast and central North China. The results revealed that herbaceous marsh vegetation's biomass density ranged from small to large in the temperate humid and semihumid marsh regions (182.3 gC m-2), Tibetan Plateau marsh area (243.9 gC m-2), temperate arid, semi-arid marsh regions (300.5 gC m-2), and subtropical humid marsh regions (348.4 G C m-2), and coastal marsh areas (675.4 C m-2). Despite the fact that the average biomass density for herbaceous marsh vegetation is lowest in the temperate humid, semi-humid marsh regions is low, it is the largest area (5.3104 km2) of the five marsh distribution areas. This region has the highest total aboveground biomass of herbaceous marl vegetation. The average aboveground biomass density for herbaceous marl vegetation in the coastal marsh is also the highest. However, the area of herbaceous marsh is the smallest (0.22104 km2) of the five marsh areas. The total aboveground biomass for coastal herbaceous marsh plants is therefore the lowest.The spatial distribution of biomass in herbaceous marsh vegetation shows non-zonality properties, but also a certain law of zonality in some areas. The aboveground biomass of vegetation in subtropical humid marsh or coastal marsh regions has no apparent correlation with hydrothermal conditions or altitude. The subtropical humid marsh and coastal marsh regions have more favorable hydrothermal conditions that are conducive to vegetation growth. These regions have more prominent non-zonality characteristics for herbaceous marsh plant species.The Tibetan Plateau's biomass of herbaceous marsh declines with elevation. The environment becomes more savage as the altitude increases. The ability of plants to get maximum photosynthetic power decreases. This results in low aboveground biomass at high altitude regions.The aboveground biomass of herbaceous marsh plants in temperate arid, semi-arid, and temperate humid regions decreased first and then didn't change with the aggravation to drought. This could be due to the fact that soil water availability in temperate regions decreases with the severity of drought.The aboveground biomass of herbaceous marsh vegetation in the temperate humid or semi-humid regions is higher than that found in warmer areas. Low aboveground biomass density in cold regions may be due to poor climate conditions and low vegetation coverage.More information: Xiangjin Shen et al., Aboveground biomass, its spatial distribution pattern, herbaceous marsh vegetative in China, Science China Earth Sciences (2021). Information from Science China Earth Sciences Xiangjin Shen et al., Aboveground biomass & its spatial distribution pattern for herbaceous marsh vegeta in China, (2021). DOI: 10.1007/s11430-020-97778-7