摘要
Background Trees in natural forests are a major contributor to atmospheric methane(CH_(4)),yet these emissions have never been investigated in reclaimed forests.Our study aimed to assess the magnitude,seasonality,drivers,and contributions of tree CH_(4) emissions to ecosystem CH_(4) fux in the reclaimed forests.We measured CH_(4) emissions from different emission pathways,including the stems of trees(Populus euramericana,Metasequoia glyptostroboides,and Camphora ofcinarum),shoots of herbs(Carex breviculmis and Carex dispalata),and soils in the two reclaimed forests with reclamation periods of 12 and 5 years.We identifed factors controlling seasonal tree CH_(4) emissions and measured tree morphological variables(diameter at breast height,wood density,and lenticel density)to determine species diferences in emissions.Results CH_(4) emissions from trees in the 12-year-old reclaimed forest were signifcantly higher than those in the 5-year-old forest.Seasonal variations in tree CH_(4) emissions were primarily driven by growth stage and soil parameters,including soil CH_(4) fux,temperature,and moisture.Conclusion In the reclaimed forests,tree-mediated CH_(4) emissions could be an important contributor to ecosystem CH_(4) fux,with contributions varying by season.As these forests mature and become ecologically restored,they may signifcantly impact regional and global CH_(4) emissions.
基金
supported by the National Natural Science Foundation of China(52204190).
