Thaw-induced impacts on land and water in discontinuous permafrost: A review of the Taiga Plains and Taiga Shield, northwestern Canada

Wright, Stephanie; Thompson, Lauren; Olefeldt, David; Connon, Ryan F.; Carpino, Olivia; Beel, C. R.; Quinton, William L.

doi:10.1016/j.earscirev.2022.104104

Cited by 20 publications

(18 citation statements)

References 186 publications

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“…At the sporadic permafrost (SCC) and discontinuous permafrost sites (SMC), permafrost degradation was initiated nearly 50-60 years ago (Wright et al 2022), which coincides with our reconstructed changes in vegetation succession and peat accumulation. Both sites are characterized by expanding permafrost-free thermokarst wetlands surrounded by thawing permafrost peat plateaus (Connon et al 2018, Haynes et al 2018).…”

Section: Recent Climate-change-induced Permafrost Thawsupporting

confidence: 76%

“…In our homogenized climate data, no increase in total annual precipitation was detected across the climate and permafrost gradient over the periods 1950-2017 and 1980-2017. At the same time, a widespread and rapid thaw of relatively warm and ice-rich permafrost has been observed in the Taiga Plains (Burn et al 2009, Wright et al 2022.…”

Section: Recent Climate-change-induced Permafrost Thawmentioning

confidence: 96%

“…Three study sites in the Mackenzie River valley of the Taiga Plains ecozone were selected, from south to north along a climate and permafrost gradient (figures 1 and 2): Scotty Creek (SCC), Smith Creek (SMC) and Havikpak Creek (HPC). The regional climate is continental with long, cold winters and short, cool summers (Wright et al 2022). Following the deglaciation of the Laurentide Ice Sheet around 11 ka BP (Lemmen et al 1994), cooling conditions led to permafrost aggradation around 6-5 ka BP in the northern part of the Taiga Plains known as the Peel Plateau region (Zoltai 1995, Vardy et al 1998), and around 4-3 ka BP in the Great Slave Lowlands Tarnocai 1975, Zoltai 1993).…”

Section: Study Sites and Samplingmentioning

confidence: 99%

“…Following the deglaciation of the Laurentide Ice Sheet around 11 ka BP (Lemmen et al 1994), cooling conditions led to permafrost aggradation around 6-5 ka BP in the northern part of the Taiga Plains known as the Peel Plateau region (Zoltai 1995, Vardy et al 1998), and around 4-3 ka BP in the Great Slave Lowlands Tarnocai 1975, Zoltai 1993). Poorly drained lacustrine deposits from the postglacial Lake McConnell, as well as a low relief, led to the establishment of thick organic deposits and development of extensive peat landscapes (Wright et al 2022).…”

Section: Study Sites and Samplingmentioning

confidence: 99%

“…Continued climate warming and the associated thaw of ice-rich permafrost near the southern limit of permafrost have already transformed some forested landscapes into thermokarst lakes and wetland ecosystems in the Taiga Plains (Quinton et al 2009, Quinton et al 2019, Wright et al 2022. There, thaw-induced land cover changes have led to the increasing hydrological connectivity of the fragmented landscape comprising saturated, partly inundated wetlands Quinton and Baltzer (2013).…”

Section: Introductionmentioning

confidence: 99%

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Recent peat and carbon accumulation on changing permafrost landforms along the Mackenzie River valley, Northwest Territories, Canada

Germain Chartrand,

Sonnentag,

Sanderson

et al. 2023

Environ. Res. Lett.

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Northwestern Canada is currently warming nearly four times faster than the global average, driving accelerated permafrost thaw and changes to ecosystem vegetation, hydrology, and landscape structure across the landscape. While permafrost peatlands constitute a large carbon reservoir, there is no consensus yet on the direction and magnitude of changes to their vulnerable carbon balance. Here, we assessed changes in peatland ecosystems following permafrost thaw at three sites located along a 1000 km-long climate and permafrost gradient along the Mackenzie River valley, Canada. Specifically, we examined vegetation succession over the last few decades to evaluate the impact of climate warming on peat and carbon accumulation. Results from the palaeoecological analysis of 20 surficial peat cores, supported by robust chronologies, show a return to peat accumulation since ca. 1980 CE in the sporadic and discontinuous permafrost zones and ca. 2000 CE in the continuous permafrost zone. Rates of peat and carbon accumulation reached 4 mm yr-1 and 134 g C m-2 yr-1 at the northernmost site in the continuous permafrost zone. In contrast, peat and carbon accumulation reached 3 mm yr-1 and 81 g C m-2 yr-1, respectively, in the sporadic and discontinuous permafrost zones. This study highlights the need for a net carbon budget that integrates the recent accelerated Sphagnum growth and carbon uptake from the atmosphere to better assess the potential carbon emissions offset following permafrost thaw. High-resolution palaeoecological studies can offer insights into decadal-scale patterns of vegetation and carbon balance changes to improve model predictions of peat climate-carbon cycle feedbacks.

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Section: Recent Climate-change-induced Permafrost Thawsupporting

confidence: 76%

Section: Recent Climate-change-induced Permafrost Thawmentioning

confidence: 96%