Uncertainty and dynamics of natural wetland CH4 release in China: Research status and priorities

摘要: Abstract Natural wetlands represent the largest single source of methane (CH 4 ), a potent greenhouse gas. China is home to world's fourth wetland area, and it facing intense climate- human-related impacts. The scientific community in has invested considerable effort into investigating CH release its dynamics. Static chamber eddy covariance observations have verified temperature, water regime air pressure as factors that regulate diurnal seasonal variation release. Non-growing seasons, especially freezing–thawing cycles, play role However, knowledge gap still exists with respect inter-annual variability Observations also suggest temperature regimes control micro- macro-scale spatial pattern release, respectively. Recent bookkeeping surveys, biogeochemical model simulations, chemical transport inversions, narrowed uncertainty range national 2.46–3.20, 2.77–4.95 2.38–4.91 Tg yr −1 , Wetland loss (especially cropland conversion Northeast China), despite climate changes, decreased by 45.2%–52.2% from 1950s–2000s, 13.2%–15.4% 1980s–2000s. future warmer temperatures rising CO 2 are predicted strengthen 32% (RCP2.6), 55% (RCP4.5) 91% (RCP8.5) 2080s, albeit without extent having been considered. Furthermore, research should emphasize mechanisms involved during cycles interannual variability. Model–data fusion manipulative experiments, warming enrichment, would benefit estimations projections