Effects of whole‐soil warming on CH4 and N2O fluxes in an alpine grassland

Abstract Global climate warming could affect the methane (CH 4 ) and nitrous oxide (N 2 O) fluxes between soils and the atmosphere, but how CH 4 and N 2 O fluxes respond to whole‐soil warming is unclear. Here, we for the first time investigated the effects of whole‐soil warming on CH 4 and N 2 O fluxes in an alpine grassland ecosystem on the Tibetan Plateau, and also studied the effects of experimental warming on CH 4 and N 2 O fluxes across terrestrial ecosystems through a global‐scale meta‐analysis. The whole‐soil warming (0–100 cm, +4°C) significantly elevated soil N 2 O emission by 101%, but had a minor effect on soil CH 4 uptake. However, the meta‐analysis revealed that experimental warming did not significantly alter CH 4 and N 2 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 2 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 4 and N 2 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.