Warming increases isoprene emissions from an arctic fen.

Area of Science:

• Arctic ecology
• Biogeochemistry
• Climate change science

Background:

• High-latitude dry ecosystems show strong temperature-dependent biogenic volatile organic compound (BVOC) emissions.
• Wetland ecosystems, with their unique cooling mechanisms, have unknown responses to warming.
• Arctic climate change may increase snowfall, affecting growing season length, soil insulation, moisture, and nutrient availability, with unknown impacts on BVOCs.

Purpose of the Study:

• To investigate the impact of warming and increased snow depth on BVOC emissions in a Greenlandic fen ecosystem.
• To determine if Arctic wetlands exhibit similar temperature sensitivity in BVOC emissions as drier ecosystems.
• To understand the role of snow depth on BVOC emissions and its interaction with temperature.

Main Methods:

• In situ measurements of BVOC emissions across a growing season using open top chambers for warming and snow fences for snow addition.
• Gas chromatography-mass spectrometry analysis of BVOC samples collected via an enclosure technique.
• Measurement of Gross Ecosystem Production (GEP) using a closed chamber technique to assess photosynthetic responses.

Main Results:

• Isoprene constituted 84-92% of total BVOC emissions.
• A 1.3-1.6°C temperature increase led to 240-340% rises in isoprene emissions.
• Isoprene emissions were significantly higher in a warmer year (2.4°C higher canopy air temperature), increasing 25-fold.
• Increased snow depth did not significantly affect isoprene emissions, despite a 24% increase in GEP.

Conclusions:

• Arctic wetland BVOC emissions are highly sensitive to rising temperatures.
• Future warming in the Arctic is predicted to cause substantial increases in BVOC emissions from wet ecosystems.
• Snow depth manipulation did not alter BVOC emissions, suggesting temperature is the dominant factor in this environment.