Methane
Mean soil CH4 fluxes (µg CH4-C m-2 h-1) for the reference, buffer, and no buffer sites for the entire sampling period (June to September) were -26.3 ± 17.7, -19.7 ± 21.6, and -9.1 ± 22.2, respectively (Figure 4B). Therefore, on average, all of the treatments were a net CH4 sink over the study period. Based on the LME model, CH4 uptake was significantly different between treatments (R - NB: p < 0.01, Table 2); CH4uptake was on average 1.26 times lower at the buffer sites than the reference sites, and 3.71 times lower at the no buffer sites than the reference sites. CH4 fluxes were significantly (p < 0.001) different between local groundwater conditions, with CH4 uptake being significantly lower in the DIS areas (Figure 5). CH4 gas flux was -11.2 ± 22.5 µg CH4 m-2 h-1 at the DIS areas while -24.4 ± 19.2 µg CH4m-2 h-1 at the ND sites, on average, for the entire study period. Soil moisture and depth to groundwater were significant predictors of CH4 fluxes according to the LME models, with a marginal r2 of 0.37 and 0.46, respectively. For every percent increase in soil moisture, mean CH4 flux rate increased by 0.50 µg. For every cm increase in depth to the groundwater table, mean CH4flux rate decreased by 0.67 µg.