Disequilibrium response of permafrost in boreal continental western Canada to climate change

Halsey, Linda A.; Vitt, Dale H.; Zoltai, S. C.

doi:10.1007/bf01093225

Cited by 153 publications

(135 citation statements)

References 31 publications

Supporting

Mentioning

129

Contrasting

Unclassified

Order By: Relevance

“…The insulating properties of peat are expected to preserve permafrost in peatland areas from severe degradation (Shur and Jorgenson, 2007;Yi et al, 2007). Currently, relict permafrost formed during the Little Ice Age is found in isolated patches within Canadian bogs despite warmer air temperatures (Halsey et al, 1995;Vitt et al, 1994). Additionally, peat depth is an important control on the active layer depth (Fukui et al, 2008;Yi et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

et al. 2011

View full text Add to dashboard Cite

Abstract. Northern peatlands contain a large terrestrial carbon pool that plays an important role in the Earth's carbon cycle. A considerable fraction of this carbon pool is currently in permafrost and is biogeochemically relatively inert; this will change with increasing soil temperatures as a result of climate warming in the 21st century. We use a geospatially explicit representation of peat areas and peat depth from a recently-compiled database and a geothermal model to estimate northern North America soil temperature responses to predicted changes in air temperature. We find that, despite a widespread decline in the areas classified as permafrost, soil temperatures in peatlands respond more slowly to increases in air temperature owing to the insulating properties of peat. We estimate that an additional 670 km 3 of peat soils in North America, containing ∼33 Pg C, could be seasonally thawed by the end of the century, representing ∼20 % of the total peat volume in Alaska and Canada. Warming conditions result in a lengthening of the soil thaw period by ∼40 days, averaged over the model domain. These changes have potentially important implications for the carbon balance of peat soils.

show abstract

Section: Introductionmentioning

confidence: 99%

Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

et al. 2011

View full text Add to dashboard Cite

show abstract

“…This is likely because the maximum thickness of snow exceeds 1 m at the end of the winter remaining on the ground from mid-December to midApril, resulting in a large offset between the GST and SAT (Zhang, 2005;Grosse et al, 2016). Our study suggests that borehole temperature profiles could be used in the future to assess the reality of the permafrost retreat assumed to have occurred after the LIA (Halsey et al, 1995;Schuur et al, 2008). Furthermore, borehole temperature profiles might be a better means for determining the southern extent of areas of past and present permafrost than current permafrost maps and a useful tool for validation of climate models.…”

Section: Discussionmentioning

confidence: 89%

Climate trends in northern Ontario and Québec from borehole temperature profiles

2016

View full text Add to dashboard Cite

Abstract. The ground surface temperature histories of the past 500 years were reconstructed at 10 sites containing 18 boreholes in northeastern Canada. The boreholes, between 400 and 800 m deep, are located north of 51 • N and west and east of James Bay in northern Ontario and Québec. We find that both sides of James Bay have experienced similar ground surface temperature histories with a warming of 1.51 ± 0.76 K during the period of 1850 to 2000, similar to borehole reconstructions for the southern portion of the Superior Province and in agreement with available proxy data. A cooling period corresponding to the Little Ice Age was found at only one site. Despite permafrost maps locating the sites in a region of discontinuous permafrost, the ground surface temperature histories suggest that the potential for permafrost was minimal to absent over the past 500 years. This could be the result of air surface temperature interpolation used in permafrost models being unsuitable to account for the spatial variability of ground temperatures along with an offset between ground and air surface temperatures due to the snow cover.

show abstract

“…Individual study plots were located within the upland forest (UL), peat plateau (PP; in Anzac site, a lichen-populated peat bog was used as ecologically comparable substitute), and a collapse feature (CS; in Anzac site, collapse feature was represented by an internal lawn; in Fort Simpson and Norman Wells, collapse scars; and in Inuvik a polygonal trench). Internal lawns are characteristically less than 50 cm lower than the surrounding bog and contain dead stands of Picea mariana and a Sphagnum ground cover [16].…”

Section: Site Descriptionmentioning

confidence: 99%

“…Internal lawns are characteristically less than 50 cm lower than the surrounding bog and contain dead stands of Picea mariana and a Sphagnum ground cover [16]. the upland forest (UL), peat plateau (PP; in Anzac site, a lichen-populated peat bog was used as ecologically comparable substitute), and a collapse feature (CS; in Anzac site, collapse feature was represented by an internal lawn; in Fort Simpson and Norman Wells, collapse scars; and in Inuvik a polygonal trench).…”

Section: Site Descriptionmentioning

confidence: 99%

See 1 more Smart Citation

Surface CO2 Exchange Dynamics across a Climatic Gradient in McKenzie Valley: Effect of Landforms, Climate and Permafrost

Startsev

Bhatti

Jassal

2016

Forests

View full text Add to dashboard Cite

Abstract:Northern regions are experiencing considerable climate change affecting the state of permafrost, peat accumulation rates, and the large pool of carbon (C) stored in soil, thereby emphasizing the importance of monitoring surface C fluxes in different landform sites along a climate gradient. We studied surface net C exchange (NCE) and ecosystem respiration (ER) across different landforms (upland, peat plateau, collapse scar) in mid-boreal to high subarctic ecoregions in the Mackenzie Valley of northwestern Canada for three years. NCE and ER were measured using automatic CO 2 chambers (ADC, Bioscientific LTD., Herts, England), and soil respiration (SR) was measured with solid state infrared CO 2 sensors (Carbocaps, Vaisala, Vantaa, Finland) using the concentration gradient technique. Both NCE and ER were primarily controlled by soil temperature in the upper horizons. In upland forest locations, ER varied from 583 to 214 g C·m −2 ·year −1 from mid-boreal to high subarctic zones, respectively. For the bog and peat plateau areas, ER was less than half that at the upland locations. Of SR, nearly 75% was generated in the upper 5 cm layer composed of live bryophytes and actively decomposing fibric material. Our results suggest that for the upland and bog locations, ER significantly exceeded NCE. Bryophyte NCE was greatest in continuously waterlogged collapsed areas and was negligible in other locations. Overall, upland forest sites were sources of CO 2 (from 64 g·C·m −2 ·year −1 in the high subarctic to 588 g C·m −2 ·year −1 in mid-boreal zone); collapsed areas were sinks of C, especially in high subarctic (from 27 g· C· m −2 year −1 in mid-boreal to 86 g·C·m −2 ·year −1 in high subarctic) and peat plateaus were minor sources (from 153 g· C· m −2 · year −1 in mid-boreal to 6 g·C·m −2 ·year −1 in high subarctic). The results are important in understanding how different landforms are responding to climate change and would be useful in modeling the effect of future climate change on the soil C balance in the northern regions.

show abstract

Disequilibrium response of permafrost in boreal continental western Canada to climate change

Cited by 153 publications

References 31 publications

Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

Climate trends in northern Ontario and Québec from borehole temperature profiles

Surface CO2 Exchange Dynamics across a Climatic Gradient in McKenzie Valley: Effect of Landforms, Climate and Permafrost

Contact Info

Product

Resources

About