Restored wetlands are a complex mosaic of open water and new and old emergent vegetation
patches, where multiple environmental and biological drivers contribute to the measured heterogeneity in
methane (CH4) flux. In this analysis, we replicated the measurements of CH4 flux using the eddy covariance
technique at three tower locations within the same wetland site to parse the spatiotemporal variability in
CH4 flux contributed by large-scale seasonal variations in climate and phenology and short-term variations
in flux footprint movement over a mosaic of vegetation and open water. Using a hierarchical statistical
model accounting for site-level environmental effects, tower-level footprint and biological effects, and
temporal autocorrelation, we partitioned the key drivers of the daily CH4 flux variability among the three
replicated towers. The daily mean air temperature and mean friction velocity, a measure of momentum
transfer, explained a significant variability in CH4 flux across the three towers, and the abundance and spatial
aggregation of vegetation in the flux footprint along with the daily gross primary productivity explained
much of the tower-level variability. This statistical model captured 67% of the total variance in the daily
integrated growing season CH4 fluxes at this site, which bridged an order of magnitude from 80 to
480mgCm-2 d-1 during the measurement period from 10 May 2012 to 24 October 2012.
