Net Ecosystem Carbon Balance of a Peat Bog Undergoing Restoration: Integrating CO2 and CH4 Fluxes From Eddy Covariance and Aquatic Evasion With DOC Drainage Fluxes

Abstract

AbstractPeatland ecosystems are generally carbon (C) sinks. However, the role of dissolved organic C (DOC) relative to gaseous fluxes of CO2 and CH4 in the C balance of these ecosystems has not often been studied. Dissolved C fluxes are important for understanding C partitioning within the peatland and the potential C drainage from it. This research was conducted in Burns Bog, a heavily impacted ecosystem near Vancouver, Canada, undergoing ecological restoration efforts by rewetting. Here we present data on (i) ecosystem‐scale fluxes of CO2 (net ecosystem exchange, NEE) and CH4 (FCH4) determined by eddy covariance, (ii) evasion fluxes of CO2 and CH4 from the water surface to estimate the role of open water in ecosystem‐scale fluxes, and (iii) DOC flux (fDOC) in water draining from the peatland. Our results showed that open water areas inside the footprint were a continual C source, emitting 47.0 ± 2.4 g C·m−2·year−1. DOC export (15.6 g C·m−2·year−1) was significant to the net ecosystem C balance, decreasing the magnitude of the eddy covariance‐determined C balance (i.e., NEE + FCH4) of −45.0 ± 16.8 g C·m−2·year−1 by 35%, resulting in a net ecosystem C balance (i.e., NEE + FCH4 + fDOC) of −29.7 ± 17.0 g C·m−2·year−1. Most of this offset occurred during the wetter nongrowing season when gross primary production was low and fDOC was relatively high.