Seasonal variations in methane fluxes in response to summer warming and leaf litter addition in a subarctic heath ecosystem

• DOI: 10.1002/2017jg003782
• Publication Date: 2017-08-14T13:36:41Z
• Authors: Emily Pickering P...; Bo Elberling; Anders Michelsen
• Keywords: Subarctic climate; Carbon sink; Sink (geography); Growing season; Litter

Abstract Methane (CH 4 ) is a powerful greenhouse gas controlled by both biotic and abiotic processes. Few studies have investigated CH fluxes in subarctic heath ecosystems, climate change‐induced shifts flux the overall carbon budget are therefore largely unknown. Hence, there an urgent need for long‐term situ experiments allowing study of ecosystem processes over time scales relevant to environmental change. Here we present CO 2 measurements from wet northern Sweden subjected 16 years manipulations, including summer warming with open‐top chambers, birch leaf litter addition, combination thereof. Throughout snow‐free season, was net sink −0.27 mg C m −2 d −1 ; exchange −1827 ), highest uptake rates (−0.70 during fall. Warming enhanced flux, while governed soil moisture. Litter addition significantly increased rates, explained pronounced drying effect up 32% relative ambient conditions. Both also seasonal average concentration dissolved organic soil. The site 60 g season. However, reduced 77%, suggesting that this type might shift season source increasing temperatures.