Greenhouse gas production and consumption in High Arctic deserts

Abstract

Polar deserts dominate the High Arctic covering over 1 358 000 km² but little is known about greenhouse gas (GHG) production or flux in polar desert soils. We measured soil-atmosphere GHG exchange for CO₂, CH₄, and N₂O, and net production of these gases in the active layer at 30 sites across three polar deserts in the High Arctic on Ellesmere Island, Canada for a total of 180 production/consumption estimates. There was inter-annual consistency in patterns of GHG net production and a consistent, significant, positive relationship (<i>r</i>² = 0.91–0.93; <i>p</i> < 0.05) between CO₂ production and N₂O production in Arctic desert sites. This differs from the negative correlations found in wet or moist tundra ecosystems and may arise from the large N₂O emissions in dolomitic desert ecosystems. Global change processes that increase microbial activity in deserts will likely increase N₂O emissions but increases in activity in wetter tundra will decrease N₂O emissions. However, given the unusual co-consumption of CH₄ and N₂O in the deserts, it is not clear if models of GHG production developed for other ecosystems will apply to these unique Arctic environments.