Towards quantifying the negative feedback regulation of peatland evaporation to drought

Citations Over TimeTop 10% of 2013 papers

Abstract

Abstract The frequency and intensity of drought is projected to increase within the boreal region under future climatic conditions. Peatlands are widely considered to regulate water loss under drought conditions, increasing surface resistance ( r s ) and reducing evaporative losses. This maintains peat moisture content, increasing the resilience of these globally important carbon stores. However, the magnitude and form of this important negative feedback response remains uncertain. To address this, we monitored the response of r s to drought within four peat cores under controlled meteorological conditions. When the water‐table was dropped to a depth of 0.30 m and the humidity reduced to ≤40%, a step shift in r s from ~50 s m ‐1 up to 1000 s m ‐1 was observed within burned and unburned peat, which virtually shuts down evaporation, limiting water loss. We show that measured near‐surface tension cannot be used to directly calculate this transition in peat surface resistance. However, empirical relationships that account for strong vertical variations in tension through the near‐surface and/or disequilibrium between pore air and near‐surface pore water pressure provide the potential to incorporate this negative feedback response into peatland ecohydrological models. Further observations are necessary to examine this response under dynamic atmospheric conditions. We suggest that the link between surface temperature and evaporation provides potential to further examine this feedback in either burned peatlands or peatlands with a low vascular vegetation cover. Copyright © 2013 John Wiley & Sons, Ltd.

Related Papers

• → Development of Sphagnum-dominated peatlands in boreal continental Canada(1993)215 cited
• → Quantification of peatland water storage capacity using the water table fluctuation method(2016)45 cited
• → Sphagnum moss moisture retention following the re‐vegetation of degraded peatlands(2010)33 cited
• → The effect of smelting operations on peatlands near Sudbury, Ontario, Canada(1986)47 cited
• → THE COMPOSITION OF THE ORGANIC MATTER AND MICROELEMENTS OF SPHAGNUM PEATS IN THE NORTHERN PART OF THE VASYUGAN PEAT DEPOSIT AND DIRECTIONS FOR THEIR USE(2023)2 cited