We measured the year-round turbulent fluxes of CO2 and CH4 using the eddy-covariance (EC) approach from 10th June 2015 to 30th June 2016. The flux tower was built on a floating platform and equipped with EC systems comprising Campbell Scientific Inc. CSAT3 3-D sonic anemometers and CO2 and CH4 open-path analyzers (LI-COR Inc. LI-7500 and LI-7700, respectively), and several sensors for measuring micrometeorological variables. The daily average net ecosystem exchange (NEE) of CO2 was -0.98 (±2.74) and -0.14 (±1.54) g C m-2 day-1 in summer and winter months, respectively. The daily average CH4 emission was 0.15 (±0.36) and 0.09 (±0.96) g C m-2 day-1 in summer and winter months, respectively. The daily average net GHG flux from CO2 and CH4 totaled to 1.63 g CO2e m-2 day-1 (-2.33 for CO2, 3.96 for CH4) in the second half of 2015 by using global warming potential (GWP). Oxygen limitation due to the high water table caused by the restoration strategy suppressed ecosystem respiration (Re) and promoted substantial CH4 formation under anoxic conditions in the summer months. With low temperatures in winter months, CH4 emission was more suppressed than Re. The key environmental factors controlling the seasonal dynamics of these exchanges in the BBECA were soil temperature and water table depth.
Supplementary URL: http://ibis.geog.ubc.ca/~achristn/research/Burns-Bog/