## 2 Study Site and Methodology
### Ecosystem Components of Carbon Metabolism
This case points to the domination of total (positive daytime \(\pm\) nighttime fluxes) \(R_{\rm E}\) over GPP (negative flux) throughout most of the study period, especially, towards the end of the period during which GPP decreased at a faster rate than \(R_{\rm E}\) (Figures 8 and 9). During the peak growing season in July, GPP peaked and decreased as the season progressed. Over the study period, GPP was on average \(-\)0.74 \(\pm\) 0.43 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) (\(-\)175 \(\pm\) 102 kg C ha\({}^{-1}\) day\({}^{-1}\)) and \(-\)0.35 \(\pm\) 0.18 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) (-2 \(\pm\) 41 kg C ha\({}^{-1}\) day\({}^{-1}\)) according to Equations (6) and (11), respectively. On average, nighttime \(R_{\rm E}\) was estimated at 0.23 \(\pm\) 0.09 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) (53 \(\pm\) 22 kg C ha\({}^{-1}\) day\({}^{-1}\)) based on the EC sensors, while daytime \(R_{\rm E}\) values were 0.64 \(\pm\) 0.31 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) (150 \(\pm\) 74 kg C ha\({}^{-1}\) day\({}^{-1}\)) and 0.24 \(\pm\) 0.05 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) (57 \(\pm\) 11 kg C ha\({}^{-1}\) day\({}^{-1}\)) based on Equations (6) and (11), respectively. Figure 12: A comparison of SWC _versus_ daytime \(R_{\rm E}\) based on Equation (6) for the Yenicaga peatland (\(R^{2}_{\rm adj}=39.2\%\); SE = 0.245; \(n=896\); \(P<0.001\)). Figure 13: A comparison of SWC _versus_ daytime \(R_{\rm E}\) based on Equation (11) for the Yenicaga peatland (\(R^{2}_{\rm adj}=68.7\%\); SE = 0.025; \(n=896\); \(P<0.001\)). Figure 14: Quantification of relationship between PAR and GPP based on Equation (6) for the Yenicaga peatland (\(R^{2}_{\text{adj}}=80.3\%\); \(\text{SE}=0.1929\); \(n=896\); \(P<0.001\)). Figure 15: Quantification of relationship between PAR and GPP based on Equation (11) for the Yenicaga peatland (\(R^{2}_{\text{adj}}=55.0\%\); \(\text{SE}=0.1182\); \(n=896\); \(P<0.001\)). Peatlands (bog hummock, bog hallow, and poor fen) in a cool temperate region of eastern Canada were reported to have NEE range from \(-\)0.18 to 0.13 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\); nighttime \(R_{\rm E}\) range from 0.07 to 0.36 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\); and GPP range from \(-\)0.20 to \(-\)0.33 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\)[15, 16]. The reported ranges of NEE, \(R_{\rm E}\) and GPP values are in a close agreement with our findings for the Yenicaga peatland [NEE = 0.11 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) based on the EC data; nighttime \(R_{\rm E}\) = 0.23 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) based on the EC data; daytime \(R_{\rm E}\) = 0.24 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) based on Equation (11); daytime \(R_{\rm E}\) = 0.64 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) based on Equation (6); GPP = \(-\)0.35 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) based on Equation (11); and GPP = \(-\)0.74 mg CO\({}_{2}\) m\({}^{-2}\) s\({}^{-1}\) based on Equation (6)], in particular, based on Equation (11). Similarly, EC measurements from 12 wetlands ranging from ombrothophic and minerotrophic peatlands to wet tundra ecosystems across Europe and North America under temperate-to-arctic climate regimes showed that CO\({}_{2}\) fluxes in July varied considerably between \(-\)3 and 1 g C m\({}^{-2}\) day\({}^{-1}\) for NEE; 1 and 4 g C m\({}^{-2}\) day\({}^{-1}\) for \(R_{\rm E}\); and \(-\)1 and \(-\)6 g C m\({}^{-2}\) day\({}^{-1}\) for GPP [17], which were close to our results.