Carbon dioxide fluxes and DOC concentrations of eroding blanket peat gullies

Abstract

UK peatlands are affected by severe gully erosion with consequent impacts on ecosystem services from these areas. Incision into the peat can damage the vegetation and hydrology and lead to increases in carbon loss and sediment transfer downstream. Gullies represent then a conduit for and a hotspot of carbon loss but the relatively high water tables of gullies have meant that they have been identified as areas with a high restoration potential because of easily restored peat‐forming conditions. This study uses a series of gully sites, subject to different restoration interventions, to investigate differences in carbon pathways (DOC, CO2) and hydrology between restoration strategies and gully position. The results show that the position within the gully (interfluve, gully side, or gully floor) does not significantly affect water quality but that it plays a significant role in CO2 exchange. Gully floors are areas of high photosynthesis and ecosystem respiration, though net ecosystem exchange is not significantly different across the gully. While gully position plays a role in the cycling of some carbon species, this study highlights the importance of vegetation as a key control on carbon cycling. Copyright © 2012 John Wiley & Sons, Ltd.

The role of waterborne carbon in the greenhouse gas balance of drained and re-wetted peatlands

“…In a study of a highly modified German peatland, Frank et al (2014) Nieminen, 2004;Schelker et al, 2012;Nieminen et al, 2014). Within semi-natural peatlands, Clay et al (2012) measured higher DOC concentrations in an eroded compared to a natural peat catchment, and some studies have suggested that moorland burning may enhance DOC loss rates (e.g. Holden et al, 2012 and references therein).…”

Restoration effects on water table depths and CO2 fluxes from climatically marginal blanket bog

“…All instrumentation was installed at least 1 month prior to the first set of readings. Topographic wetness indices (TWI, Beven and Kirkby 1979) were calculated for each site ( 'gully' sites (with the exception of SL.HB-G) plots were laid out in transects across the gully (see Clay et al 2012 Fig. 2) with collars sampling interfluves at gully-edges, gully-walls and gully-floors.…”

“…This study employed a portable infra-red gas analyser (EGM-4, PP-Systems, Hitchin, UK) with a clear 20 cm tall, 15 cm diameter acrylic closed chamber (CPY-2, PP-Systems, Hitchin, UK) to measure fluxes of CO2 from permanently installed gas collars. The protocols employed in the measurement of CO2 fluxes were in line with previous research in the area (Clay et al 2012;Rowson et al 2010;Worrall et al 2011). Light (net ecosystem exchange-NEE) and dark (ecosystem respiration-Reco) readings were taken at each gas collar alongside air temperature and photosynthetically active radiation (PAR) readings.…”

“…Preliminary results on Bleaklow Plateau bare peat restoration have suggested that ecological restoration has improved the total C budget of restored sites relative to unrestored areas but with apparent differences between treatments. Moreover, work by Clay et al (2012)on Bleaklow drainage gullies suggested that it is the presence of vegetation rather than the geomorphology of the gully per se that is the main control on the CO2 fluxes on those sites. Following on from these papers this study continued monitoring CO2 fluxes and water table depths from restoration sites on the Bleaklow Plateau over 5 years.…”

Variations in dissolved organic carbon concentrations across peatland hillslopes

“…but not arable land (Worrall et al, 2012), while moorland burning has been suggested to affect DOC 63 concentration (Yallop and Clutterbuck, 2009) and composition (Clutterbuck and Yallop, 2010) but 64 may only be evident over short timescales (Clay et al, 2009) and may not be apparent over long 65 time periods if the degree of burning has not changed over time . Peat 66 drainage has also been shown to influence the production and export of DOC, with enhanced 67 drainage increasing DOC production and therefore DOC concentration through increased 68 decomposition of peat in the greater aerobic zone; therefore drain blocking has the effect of 69 reducing aerobic decomposition of peat and production of DOC, thus lowering DOC concentration 70 (Höll et while DOC concentrations can increase post blocking due to accumulation of dissolved organic 73 matter at depth (Glatzel et al, 2003).…”