Effects of changes in throughfall on soil GHG fluxes under a mature temperate forest, northeastern China. (15th September 2021)

• Record Type: Journal Article
• Authors: Xu, Xingkai; Duan, Cuntao; Wu, Haohao; Luo, Xianbao; Han, Lin
• Is Part Of: Journal of environmental management. Volume 294(2021)
• Publication Date: 2021-09-15
• Subjects: Climate change -- Dissolved organic carbon dynamic -- Forest ecosystem -- Greenhouse gas flux -- Nitrogen leaching -- Inter-annual variability; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2021.112950
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Climate change scenarios predict a change in the rainfall regimes for this current century, which has different impacts on soil greenhouse gas (GHG) fluxes. However, how changes in annual rainfall affect annual GHG fluxes of forest soils remain unknown. A six-year field experiment with −25% and −50% throughfall (TF) and +25% TF manipulation was performed to explore the mechanisms involving GHG fluxes under a mature temperate forest, northeastern China and to work out whether the TF effect sizes on annual soil GHG fluxes vary with dry and wet years. The results showed that both −25% TF and −50% TF treatments depressed annual soil nitrous oxide (N2 O) and carbon dioxide (CO2 ) emissions but increased annual soil methane (CH4 ) uptake. A contrary pattern of annual soil GHG fluxes was observed in the +25% TF treatment. When annual TF input was decreased by 100 mm, annual soil N2 O and CO2 emissions were decreased by 18.1 ± 3.1 mg N m −2 and by 39.4 ± 6.1 g C m −2 during the growing season, respectively, and annual soil CH4 uptake was increased by 11.5 ± 3.4 mg C m −2 . Both −25% TF and −50% TF treatments reduced annual soil dissolved organic C (DOC) leaching by 29.3% and 45.6% and dissolved total N (DN) leaching by 30.8% and 39.6%, respectively. Contrary to annual soil N2 O and CO2 emissions, annual soil CH4 uptake during the growing season significantly decreased with an increase in the annual leaching fluxes of soil DOC, inorganic N, and DN. Besides soil moisture and temperature and pH, soil GHG fluxes under manipulating TF condition were regulated by soil labile C and N status. Our findings indicated that the TF effect sizes on both annual GHG fluxes and net annual GHG balance (GWP) of forest soils varied with dry and wet years in northeastern China. The results highlight the importance of altered annual rainfall in regulating annual soil GHG fluxes and the GWP in temperate forests under global climate change. Graphical abstract: Image 1 Highlights: Effects of throughfall on soil GHG fluxes in forest ecosystems were studied. Throughfall reduction reduced soil N2 O and CO2 fluxes but increased CH4 uptake. Soil moisture and temperature jointly affected N2 O and CO2 fluxes and CH4 uptake. Soil GHG fluxes upon altered throughfall were related to soil DOC and DN leaching. Throughfall effect sizes on soil GHG fluxes and GWP varied with dry and wet years.