title: Moderate drop in water table increases peatland vulnerability to post-fire regime shift.
abstract: Northern and tropical peatlands represent a globally significant carbon reserve accumulated over thousands of years of waterlogged conditions. It is unclear whether moderate drying predicted for northern peatlands will stimulate burning and carbon losses as has occurred in their smaller tropical counterparts where the carbon legacy has been destabilized due to severe drainage and deep peat fires. Capitalizing on a unique long-term experiment, we quantify the post-wildfire recovery of a northern peatland subjected to decadal drainage. We show that the moderate drop in water table position predicted for most northern regions triggers a shift in vegetation composition previously observed within only severely disturbed tropical peatlands. The combined impact of moderate drainage followed by wildfire converted the low productivity, moss-dominated peatland to a non-carbon accumulating shrub-grass ecosystem. This new ecosystem is likely to experience a low intensity, high frequency wildfire regime, which will further deplete the legacy of stored peat carbon.
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
authors.forename: N
authors.initials: N
authors.lastname: Kettridge
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
authors.forename: M R
authors.initials: MR
authors.lastname: Turetsky
authors.affiliation: School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario, L8S 4K1, Canada.
authors.forename: J H
authors.initials: JH
authors.lastname: Sherwood
authors.affiliation: 1] School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario, L8S 4K1, Canada [2] Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, T6H 3S5, Canada.
authors.forename: D K
authors.initials: DK
authors.lastname: Thompson
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
authors.forename: C A
authors.initials: CA
authors.lastname: Miller
authors.affiliation: Department of Biological Sciences, Florida Atlantic University, Davie, Florida 33314, USA.
authors.forename: B W
authors.initials: BW
authors.lastname: Benscoter
authors.affiliation: 1] Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, T6H 3S5, Canada [2] Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2H1, Canada.
authors.forename: M D
authors.initials: MD
authors.lastname: Flannigan
authors.affiliation: 1] Faculty of Forestry, University of Toronto, Toronto, Ontario, M5S 3B3, Canada [2] Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste Marie, Ontario, P6A ZES, Canada.
authors.forename: B M
authors.initials: BM
authors.lastname: Wotton
authors.affiliation: School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario, L8S 4K1, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: Waddington