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Title: The bog landforms of continental western Canada in relation to climate and permafrost patterns

Abstract

In continental western Canada, discontinuous permafrost is almost always restricted to ombrotrophic peatlands (bogs). Bogs occur mostly as islands or peninsulas in large, often complex fens or are confined to small basins. Permafrost may be present in extensive peat plateaus (or more locally as palsas) and was preceded by a well-developed layer of Sphagnum that served to insulate the peat and lower the pore water temperatures. Air photo interpretation reveals the occurrence of bogs with five types of surface physiography. Concentrated to the south are bogs without internal patterns that have never had permafrost. Dominating the mid-latitudes are bogs with internal lawns and fens with internal lawns (mostly representing former bogs) that had permafrost lenses in the past that have recently degraded. Concentrated in the northwest are peat plateaus without internal lawns or distinct collapse scars, but with permafrost; dominating in the northernmost area are peat plateaus with extensive permafrost and collapse scars. Relationships are apparent between the current - 1[degrees]C isotherm and the southern occurrence of peat plateaus and between the 0[degrees]C isotherm and the southern edge of bogs and fens with internal lawns. We interpret bogs and fens with internal lawns to represent areas where permafrost degradation ismore » currently occurring at a greater rate than aggradation, seemingly in response to warmer regional climate, although fire frequency may also be of local importance. 54 refs., 21 figs., 2 tabs.« less

Authors:
;  [1];  [2]
  1. (Univ. of Alberta, Edmonton, Alberta (Canada))
  2. (Northern Forestry Centre, Edmonton, Alberta (Canada))
Publication Date:
OSTI Identifier:
7035157
Resource Type:
Journal Article
Resource Relation:
Journal Name: Arctic and Alpine Research (Boulder, Colorado); (United States); Journal Volume: 26:1
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; CANADA; CLIMATIC CHANGE; SWAMPS; PERMAFROST; THAWING; GEOMORPHOLOGY; PEAT; AQUATIC ECOSYSTEMS; DEVELOPED COUNTRIES; ECOSYSTEMS; ENERGY SOURCES; FOSSIL FUELS; FUELS; GEOLOGY; MATTER; NORTH AMERICA; ORGANIC MATTER; TERRESTRIAL ECOSYSTEMS; WETLANDS; 540220* - Environment, Terrestrial- Chemicals Monitoring & Transport- (1990-)

Citation Formats

Vitt, D.H., Halsey, L.A., and Zoltai, S.C.. The bog landforms of continental western Canada in relation to climate and permafrost patterns. United States: N. p., 1994. Web. doi:10.2307/1551870.
Vitt, D.H., Halsey, L.A., & Zoltai, S.C.. The bog landforms of continental western Canada in relation to climate and permafrost patterns. United States. doi:10.2307/1551870.
Vitt, D.H., Halsey, L.A., and Zoltai, S.C.. Tue . "The bog landforms of continental western Canada in relation to climate and permafrost patterns". United States. doi:10.2307/1551870.
@article{osti_7035157,
title = {The bog landforms of continental western Canada in relation to climate and permafrost patterns},
author = {Vitt, D.H. and Halsey, L.A. and Zoltai, S.C.},
abstractNote = {In continental western Canada, discontinuous permafrost is almost always restricted to ombrotrophic peatlands (bogs). Bogs occur mostly as islands or peninsulas in large, often complex fens or are confined to small basins. Permafrost may be present in extensive peat plateaus (or more locally as palsas) and was preceded by a well-developed layer of Sphagnum that served to insulate the peat and lower the pore water temperatures. Air photo interpretation reveals the occurrence of bogs with five types of surface physiography. Concentrated to the south are bogs without internal patterns that have never had permafrost. Dominating the mid-latitudes are bogs with internal lawns and fens with internal lawns (mostly representing former bogs) that had permafrost lenses in the past that have recently degraded. Concentrated in the northwest are peat plateaus without internal lawns or distinct collapse scars, but with permafrost; dominating in the northernmost area are peat plateaus with extensive permafrost and collapse scars. Relationships are apparent between the current - 1[degrees]C isotherm and the southern occurrence of peat plateaus and between the 0[degrees]C isotherm and the southern edge of bogs and fens with internal lawns. We interpret bogs and fens with internal lawns to represent areas where permafrost degradation is currently occurring at a greater rate than aggradation, seemingly in response to warmer regional climate, although fire frequency may also be of local importance. 54 refs., 21 figs., 2 tabs.},
doi = {10.2307/1551870},
journal = {Arctic and Alpine Research (Boulder, Colorado); (United States)},
number = ,
volume = 26:1,
place = {United States},
year = {Tue Feb 01 00:00:00 EST 1994},
month = {Tue Feb 01 00:00:00 EST 1994}
}
  • Over 20% of Earth’s terrestrial surface is underlain by permafrost with vast stores of carbon that, if thawed may represent the largest future transfer of C from the biosphere to the atmosphere 1. This process is largely dependent on microbial responses, but we know little about microbial activity in intact, let alone in thawing permafrost. Molecular approaches have recently revealed the identities and functional gene composition of microorganisms in some permafrost soils 2-4 and a rapid shift in functional gene composition during short-term thaw experiments 3. However, the fate of permafrost C depends on climatic, hydrologic, and microbial responses tomore » thaw at decadal scales 5, 6. Here the combination of several molecular “omics” approaches enabled us to determine the phylogenetic composition of the microbial community, including several draft genomes of novel species, their functional potential and activity in soils representing different states of thaw: intact permafrost, seasonally thawed active layer and thermokarst bog. The multi-omics strategy revealed a good correlation of process rates to omics data for dominant processes, such as methanogenesis in the bog, as well as novel survival strategies for potentially active microbes in permafrost.« less
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  • Surface temperature, precipitation, specific humidity and wind anomalies associated with the warm and cold phases of ENSO simulated by WRF and HadRM are examined for the present and future decades. WRF is driven by ECHAM5 and CCSM3, respectively, and HadRM is driven by HadCM3. For the current decades, all simulations show some capability in resolving the observed warm-dry and coolwet teleconnection patterns over the PNW and the Southwest U.S. for warm and cold ENSO. Differences in the regional simulations originate primarily from the respective driving fields. For the future decades, the warm-dry and cool-wet teleconnection patterns in association with ENSOmore » are still represented in ECHAM5-WRF and HadRM. However, there are indications of changes in the ENSO teleconnection patterns for CCSM3-WRF in the future, with wet anomalies dominating in the PNW and the Southwest U.S. for both warm and cold ENSO, in contrast to the canonical patterns of precipitation anomalies. Interaction of anomalous wind flow with local terrain plays a critical role in the generation of anomalous precipitation over the western U.S. Anomalous dry conditions are always associated with anomalous airflow that runs parallel to local mountains and wet conditions with airflow that runs perpendicular to local mountains. Future changes in temperature and precipitation associated with the ENSO events in the regional simulations indicate varying responses depending on the variables examined as well as depending on the phase of ENSO.« less
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