Interannual variability of carbon dioxide (CO2) and methane (CH4) fluxes in a rewetted temperate bog

作者：Tin W. Satriawan, Marion Nyberg, Sung‐Ching Lee, Andreas Christen, T. Andrew Black, Mark S. Johnson, Zoran Nesic, Markus Merkens, Sara Knox · 发表于：Agricultural and Forest Meteorology · 年份：2023 · DOI：10.1016/j.agrformet.2023.109696 · 被引用次数：13 · 研究领域：Peatlands and Wetlands Ecology、Coastal wetland ecosystem dynamics、Fire effects on ecosystems

Peatland rewetting, a management effort to restore water levels in previously drained peatlands, is important for re-establishing the role of these peatlands as carbon (C) sinks. Since rewetted peatlands have a highly variable response to interannual variations in climatic conditions and functional changes, long term studies of C fluxes in these ecosystems are needed. Here, we evaluated the impact of climate variability and functional change on the interannual variability of CO2 and CH4 fluxes at Burns Bog, a rewetted temperate bog on the Pacific Coast in Canada, based on five years of eddy covariance measurements. We found that the site alternated between being an annual-scale net CO2 sink or source, ranging from -32.6 ± 21.5 (±95% CI) to 11.9 ± 15.1 g CO2C m-2 yr-1, respectively, while consistently being a CH4 source, ranging from 11.6 ± 0.7 to 18.0 ± 1.6 g CH4C m-2 yr-1. Over the five-year period, mean annual CH4 emissions (13.7 ± 2.5 g CH4C m-2 yr-1; ±SD across years) entirely offset the CO2 sink (-12.3 ± 20.4 g CO2C m-2 yr-1), resulting in the site being near-carbon neutral over this period (1.3 ± 23.9 g C m-2 yr-1). This finding indicates that excluding CH4 fluxes from the net C balance results in an overestimation of the net C uptake at this site. Annual CO2 emissions from the bog were greatest in the year with a dry and warm summer, emphasizing the importance of temperature and water table depth at the bog. Regardless of the greenhouse gas (GHG) metrics (i.e., global ...