The below-ground biomass contributes more to wetland soil carbon pools than the above-ground biomass-a survey based on global wetlands

地下生物量对湿地土壤碳库的贡献大于地上生物量:一项基于全球湿地的调查

The biomass of wetland plants is highly responsive to environmental factors and plays a crucial role in the dynamics of the soil organic carbon(SOC)pool.In this study,we collected and analyzed global data on wetland plant biomass from 1980 to 2021.By examining 1134 observations from 182 published papers on wetland ecosystems,we created a comprehensive database of wetland plant above-ground biomass(AGB)and below-ground biomass(BGB).Using this database,we analyzed the biomass characteristics of different climate zones,wetland types and plant species globally.Based on this,we analyzed the differences between the biomass of different plant species and the linkage between AGB and BGB and organic carbon.Our study has revealed that wetland plant AGB is greater in equatorial regions but BGB is highest in polar areas,and lowest in arid and equatorial zones.For plant species,the BGB of the Poales is higher than the AGB but Caryophyllales,Cyperales and Lamiales have higher AGB.Moreover,our findings indicate that BGB plays a more significant role in contributing to the organic carbon pool compared to AGB.Notably,when BGB is less than 1 t C ha^(-1),even slight changes in biomass can have a significant impact on the organic carbon pool.And we observed that the SOC increases by 5.7 t C ha^(-1)when the BGB content is low,indicating that the SOC is more sensitive to changes in biomass under such circumstances.Our study provides a basis for the global response of AGB and BGB of wetland plants to organic carbon.

湿地植物生物量对环境因素高度敏感,在土壤有机碳(SOC)库的动态中起着至关重要的作用。本研究中,我们收集并分析了1980至2021年全球湿地植物生物量数据。通过检查182篇已发表的湿地生态系统论文中的1134个观测结果,我们创建了湿地植物地上生物量(AGB)和地下生物量(BGB)的综合数据库。我们利用该数据库分析了全球不同气候带、湿地类型和植物物种的生物量特征。在此基础上,我们分析了不同植物物种生物量的差异以及AGB和BGB与有机碳的联系。我们的研究表明,湿地植物AGB在赤道地区较高,但BGB在极地地区最高,在干旱和赤道地区最低。对于植物种类来说,禾本科植物的BGB高于AGB,但石竹目、莎草目和唇形科的AGB较高。此外,我们的研究结果还发现,与AGB相比,BGB在对有机碳库的贡献方面发挥着更重要的作用。值得注意的是,当BGB小于1 t C ha^(-1)时,即使生物量发生微小变化也会对有机碳库产生重大影响。我们观察到,当BGB含量较低时,SOC增加了5.7 t C ha^(-1),这表明SOC对生物量的变化在这种情况下更加敏感。我们的研究为湿地植物地上和地下生物量对有机碳的全球响应提供了基础。