College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, Peking University, Beijing, China.
Qinghai Haibei National Field Research Station of Alpine Grassland Ecosystem, and Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China.
Glob Chang Biol. 2024 Jan;30(1):e17033. doi: 10.1111/gcb.17033.
Global climate warming could affect the methane (CH ) and nitrous oxide (N O) fluxes between soils and the atmosphere, but how CH and N O fluxes respond to whole-soil warming is unclear. Here, we for the first time investigated the effects of whole-soil warming on CH and N O fluxes in an alpine grassland ecosystem on the Tibetan Plateau, and also studied the effects of experimental warming on CH and N O fluxes across terrestrial ecosystems through a global-scale meta-analysis. The whole-soil warming (0-100 cm, +4°C) significantly elevated soil N O emission by 101%, but had a minor effect on soil CH uptake. However, the meta-analysis revealed that experimental warming did not significantly alter CH and N O fluxes, and it may be that most field warming experiments could only heat the surface soils. Moreover, the warming-induced higher plant litter and available N in soils may be the main reason for the higher N O emission under whole-soil warming in the alpine grassland. We need to pay more attention to the long-term response of greenhouse gases (including CH and N O fluxes) from different soil depths to whole-soil warming over year-round, which could help us more accurately assess and predict the ecosystem-climate feedback under realistic warming scenarios in the future.
全球气候变暖可能会影响土壤与大气之间的甲烷（CH ）和氧化亚氮（N O）通量，但土壤整体变暖如何影响 CH 和 N O 通量尚不清楚。在这里，我们首次研究了青藏高原高寒草原生态系统整体土壤变暖对 CH 和 N O 通量的影响，并且还通过全球范围内的荟萃分析研究了实验变暖对陆地生态系统 CH 和 N O 通量的影响。整体土壤变暖（0-100cm，+4°C）显著增加了 101%的土壤 N O 排放，但对土壤 CH 吸收的影响较小。然而，荟萃分析表明，实验变暖并没有显著改变 CH 和 N O 通量，这可能是因为大多数野外变暖实验只能加热表层土壤。此外，变暖引起的土壤中更高的植物凋落物和可利用氮可能是高寒草原整体土壤变暖导致 N O 排放更高的主要原因。我们需要更加关注全年不同土壤深度的温室气体（包括 CH 和 N O 通量）对整体土壤变暖的长期响应，这有助于我们更准确地评估和预测未来实际变暖情景下的生态系统-气候反馈。
