Journal
SCIENCE OF THE TOTAL ENVIRONMENT
Volume 795, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.scitotenv.2021.148847
Keywords
Climate change; Tundra fire; Shrub cutting; Nitrous oxide; Carbon dioxide; Methane; Soil nutrients; In vitro incubation; Wetting
Categories
Funding
- Danish National Research Foundation [CENPERM DNRF100]
- China Scholarship Council [201806140158]
Ask authors/readers for more resources
The study found that fire has significant effects on soil biogeochemical cycles and greenhouse gas emissions in Arctic tundra regions, leading to substantial increases in soil nitrates, ammonium, and phosphate post-fire. Additionally, fire may decrease the temperature response in soil respiration, weakening the positive feedback to climate change.
The frequency and severity of fire is increasing in Arctic tundra regions with climate change. Here we investigated effects of experimental low-intensity fire and shrub cutting, in combination with warming, on soil biogeochemical cycles and post-fire greenhouse gas (GHG) emissions in a dry heath tundra, West Greenland. We performed in vitro incubation experiments based on soil samples collected for up to two years after the fire. We observed tendency for increased soil nitrate (14-fold) and significant increases in soil ammonium and phosphate (four-fold and five-fold, respectively) two years after the lire, but no effects of shrub cutting on these compounds. Thus, changes appear to be largely due to fire effects rather than indirect effects by vegetation destruction. Two years after fire, nitrous oxide (N2O) and carbon dioxide (CO2) production was significantly increased (three-fold and 32% higher, respectively), in burned than unburned soils, while methane (CH4) uptake remained unchanged. This stimulated N2O and CO2 production by the fire, however, was only apparent under conditions when soil was at maximum water holding capacity, suggesting that fire effects can be masked under dry conditions in this tundra ecosystem. There were positive effects by modest 25 degrees C warming on CO2 production in control but not in burned soils, suggesting that fire may decrease the temperature response in soil respiration. Methane uptake was neither altered by the modest warming in shrub-cut nor in burned soils after two years, suggesting that the removal of vegetation may play a key role in controlling future temperature response of CH4 oxidation. Altogether, our results show that post-fire tundra soils have the potential to enhance soil GHG emissions (e.g. N2O and CO2) especially during episodes with wet soil conditions. On the other hand, the lack of warming responses in post-fire soil respiration may weaken this positive feedback to climate change. (C) 2021 The Authors. Published by Elsevier B.V.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available