Bryophytes impact the fluxes of soil non-carbon dioxide greenhouse gases in a subalpine coniferous forest
2020
Li, Andi | DeLuca, Thomas H. | Sun, Shouqin | Zhang, Jun | Wang, Genxu
Terrestrial bryophytes substantially regulate ecosystem processes in high latitude and high elevation ecosystems; however, the role of these plants in mediating soil emissions of non-CO₂ greenhouse gases (GHGs) (N₂O and CH₄) in these ecosystems remains poorly understood. A removal experiment was conducted to investigate the influence of bryophytes on soil non-CO₂ GHGs emission in a subalpine coniferous forest on the eastern edge of the Tibetan Plateau. Bryophyte removal decreased the average N₂O emission rate, but did not significantly alter the CH₄ flux rate. The cumulative amount of N₂O emission and CH₄ uptake was decreased by bryophyte removal. Compared to bryophyte-removal plots, soil in the control plots had higher concentrations of soil organic C (SOC), total N (TN), dissolved organic C (DOC), dissolved N (DN), and exchangeable NH₄⁺. The control plots also had higher cumulative N₂O emission and CH₄ uptake compared to plots with bryophytes removed. Bryophyte-removal significantly changed the relationship between soil non-CO₂ GHGs flux rates and soil water content, induced a linear decreasing relationship between the N₂O emission rate and soil water content and a quadratic relationship between CH₄ flux rate and soil water content in the bryophyte-removal plots. Results from this study indicate that bryophytes may regulate non-GHG emissions from subalpine coniferous soils and demonstrate that in the presence of bryophytes, these soils may act as a greater N₂O source and CH₄ sink in southwestern China.
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