UK Centre for Ecology and Hydrology, Penicuik, EH26 0QB, UK.
Okavango Research Institute, University of Botswana, Maun, Botswana.
Nat Commun. 2022 Jan 10;13(1):133. doi: 10.1038/s41467-021-27786-4.
Tropical wetlands are a significant source of atmospheric methane (CH), but their importance to the global CH budget is uncertain due to a paucity of direct observations. Net wetland emissions result from complex interactions and co-variation between microbial production and oxidation in the soil, and transport to the atmosphere. Here we show that phenology is the overarching control of net CH emissions to the atmosphere from a permanent, vegetated tropical swamp in the Okavango Delta, Botswana, and we find that vegetative processes modulate net CH emissions at sub-daily to inter-annual timescales. Without considering the role played by papyrus on regulating the efflux of CH to the atmosphere, the annual budget for the entire Okavango Delta, would be under- or over-estimated by a factor of two. Our measurements demonstrate the importance of including vegetative processes such as phenological cycles into wetlands emission budgets of CH.
热带湿地是大气甲烷（CH）的重要来源，但由于直接观测数据的缺乏，其对全球 CH 预算的重要性尚不确定。湿地净排放是土壤中微生物产生和氧化之间复杂相互作用和共同变化以及向大气传输的结果。在这里，我们表明，在博茨瓦纳奥卡万戈三角洲的一个永久性植被热带沼泽中，物候是向大气中净 CH 排放的主要控制因素，我们发现植被过程在亚日至年际时间尺度上调节净 CH 排放。如果不考虑纸莎草在调节 CH 向大气排放方面的作用，整个奥卡万戈三角洲的年度预算将被低估或高估两倍。我们的测量结果表明，将物候等植被过程纳入 CH 湿地排放预算中非常重要。
