Drivers of net methane uptake across Greenlandic dry heath tundra landscapes

• Published in: Soil Biology and Biochemistry
• Main Authors: St Pierre, Kyra A., Danielsen, Birgitte Kortegaard, Hermesdorf, Lena, D'Imperio, Ludovica, Iversen, Lars Lønsmann, Elberling, Bo
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Arctic; Climate change; Greenland; Landscape; Methane oxidation; greenlandic; Tundra
• Online Access: https://curis.ku.dk/portal/da/publications/drivers-of-net-methane-uptake-across-greenlandic-dry-heath-tundra-landscapes(31368d29-d8df-4f32-acf5-6eec0615e6cd).html; https://doi.org/10.1016/j.soilbio.2019.107605

Methane (CH 4 ) is a potent greenhouse gas that is naturally produced and consumed in soil. The processes result in that soils may function as either a net sink or source of atmospheric methane. Although dry heath tundra ecosystems have recently been identified as important net sinks of atmospheric CH 4 , we understand little about how similar dry heath sites compare across both elevational gradients and wider geographical areas with regards to CH 4 fluxes. To address this shortcoming, we measured CH 4 fluxes and soil characteristics under ambient and experimental warming conditions at low and high elevation sites in South (61°N) and West (69°N) Greenland. We then used a structural equation model to explain CH 4 fluxes in relation to air temperatures and soil moisture. Soils across all sites were almost universal net CH 4 sinks (range for ambient plots: −1.2 to −3.9 μmol m −2 h −1 ). Observed soil CH 4 fluxes across all sites were significantly positively correlated to soil temperatures at 5 cm depth and negatively correlated to soil moisture. Additional factors such as soil pH and disturbance could also help to explain the differences in CH 4 fluxes between similar dry heath sites across greater spatial scales. Understanding the importance of these factors is likely critical to more accurately upscale plot-level measurements of CH 4 fluxes in constraining the terrestrial high latitude CH 4 sink.