Effects of Environmental Variables on Spatiotemporal Variations of Nitrous Oxide Fluxes in the Pristine Riparian Marsh, Northeast China

Abstract

Nitrous oxide (N₂O) is an important greenhouse gas, and the riparian marsh plays an important role in modulating atmospheric concentrations of N₂O. To investigate the effects of environmental variables on spatiotemporal variations of N₂O fluxes in the pristine riparian marsh, the static chamber-GC techniques were used to explore the spatiotemporal variations of N₂O fluxes in Calamagrostis angustifolia swamp meadow marsh (CASMM), Ecotone wetland (EW) and Carex Schmidtii Meinsh. marsh (CSMM) along the pristine riparian in Sanjiang Plain during one year. During non-growing season (October, 2015 to April, 2016), the variability of N₂O fluxes in the three marshes were not significantly different (P > 0.05). However, during growing season (May to October, 2016), both variability differences of N₂O fluxes between CSMM and EW, and between CSMM and CASMM were significant (P < 0.01). Atmospheric temperature, soil NH₄⁺-N content and soil volumetric moisture content were the driving factors during non-growing season. During growing season, soil NH₄⁺-N and NO₃⁻-N content were the driving factors among interactions of multiple environmental variables. CASMM and EW became the sinks of N₂O during non-growing season but converted to the source of N₂O during growing season. However, CSMM became all sink of N₂O during every season.

from Energy Ecology Environment Ambio via Terpsi Hori on Inoreader https://ift.tt/2EyIdvA