Methane oxidation in contrasting soil types: responses to experimental warming with implication for landscape‐integrated CH 4 budget

作者：Ludovica D’Imperio, Cecilie Skov Nielsen, Andreas Westergaard‐Nielsen, Anders Michelsen, Bo Elberling · 发表于：Global Change Biology · 年份：2016 · DOI：10.1111/gcb.13400 · 被引用次数：95 · 研究领域：Climate change and permafrost、Atmospheric and Environmental Gas Dynamics、Methane Hydrates and Related Phenomena

Abstract Arctic ecosystems are characterized by a wide range of soil moisture conditions and thermal regimes and contribute differently to the net methane ( CH 4 ) budget. Yet, it is unclear how climate change will affect the capacity of those systems to act as a net source or sink of CH 4 . Here, we present results of in situ CH 4 flux measurements made during the growing season 2014 on Disko Island (west Greenland) and quantify the contribution of contrasting soil and landscape types to the net CH 4 budget and responses to summer warming. We compared gas flux measurements from a bare soil and a dry heath, at ambient conditions and increased air temperature, using open‐top chambers ( OTC s). Throughout the growing season, bare soil consumed 0.22 ± 0.03 g CH 4 ‐C m −2 (8.1 ± 1.2 g CO 2 ‐eq m −2 ) at ambient conditions, while the dry heath consumed 0.10 ± 0.02 g CH 4 ‐C m −2 (3.9 ± 0.6 g CO 2 ‐eq m −2 ). These uptake rates were subsequently scaled to the entire study area of 0.15 km 2 , a landscape also consisting of wetlands with a seasonally integrated methane release of 0.10 ± 0.01 g CH 4 ‐C m −2 (3.7 ± 1.2 g CO 2 ‐eq m −2 ). The result was a net landscape sink of 12.71 kg CH 4 ‐C (0.48 tonne CO 2 ‐eq) during the growing season. A nonsignificant trend was noticed in seasonal CH 4 uptake rates with experimental warming, corresponding to a 2% reduction at the bare soil, and 33% increase at the dry heath. This was due to the indirect effect of OTC s on soil moisture, which exe...