Can boreal peatlands with pools be net sinks for CO2?

Abstract

Peatland open-water pools, a common feature on temperate to subarctic peatlands, are sources of carbon (C) to the atmosphere but their contribution to the net ecosystem carbon dioxide exchange (NEE-CO _2 ) is poorly known; there is a question as to whether peatlands with pools are smaller sinks of atmospheric C, or even C-neutral, compared to other peatlands. We present growing season NEE-CO _2 measurements using the eddy covariance technique in a peatland with pools. We found the maximum photosynthetic uptake and ecosystem respiration rates at 10 °C to be in the lower range of the published data. The lower total vegetation biomass, due to the presence of pools, reduced CO _2 uptake during day and the autotrophic component of ecosystem respiration. The low CO _2 uptake combined with reduced CO _2 loss resulted in the site being a net sink for CO _2 of a similar magnitude as other northern peatlands despite the inclusion of pools.

Keywords

• peatlands
• open-water pools
• carbon dioxide
• net ecosystem exchange