Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska
In the northwest corner of the Tanana Flats, a lowland basin just south of Fairbanks in interior Alaska, there is a vast network of floating-mat wetlands or fens that appears to be unique in terms of their origin, large areal extent, and absence of sphagnum moss and associated peat. During the summe...
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ftdtic:ADA241282 2023-05-15T17:57:21+02:00 Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska Racine, Charles H. Walters, James C. COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1991-07 text/html http://www.dtic.mil/docs/citations/ADA241282 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA241282 en eng http://www.dtic.mil/docs/citations/ADA241282 Approved for public release; distribution is unlimited. DTIC AND NTIS Ecology Hydrology Limnology and Potamology *AERIAL RECONNAISSANCE CALCIUM WATER FLOW WATER ALASKA GEOLOGY GROUND WATER WINTER INTERNAL HISTORY WETLANDS VEGETATION SUBSURFACE SOUTH(DIRECTION) PH FACTOR FLOATING BODIES PERMAFROST MATS FAIRBANKS(ALASKA) PEAT GROUND LEVEL *ALASKA *WETLANDS *GROUND WATER *ENVIRONMENTAL IMPACT BOG AIR CUSHION VEHICLES INTERIOR ALASKA TANANA FLATS ALKALINITY BLADDERWORT WATER HEMLOCK BUCK BEAN SWAMP HORSETAIL SEDGES MARSH FIVEFINGER Text 1991 ftdtic 2016-02-22T19:12:04Z In the northwest corner of the Tanana Flats, a lowland basin just south of Fairbanks in interior Alaska, there is a vast network of floating-mat wetlands or fens that appears to be unique in terms of their origin, large areal extent, and absence of sphagnum moss and associated peat. During the summers of 1989 and 1990 a study of the impacts of airboats on these wetlands included aerial and ground reconnaissance of 20 sites to characterize the vegetation, hydrology and subsurface conditions. These wetlands consist of a floating vegetation mat up to 1 m thick, forming an almost complete cover over deeper water bodies. The mats consist of a tall, dense and productive network of emergent vascular plants, including buckbean (menyanthes trifoliata), swamp horsetail(Equisetum fluviatile), sedges (Carexaquatilis), marshfivefinger(potentilla palustris),water hemlock (Cicuta mackenzieana) and bladderwort (Utricularia sp.). Evidence that these wetlands are formed by groundwater discharge includes (a) the apparent absence of permafrost under these wetlands but its presence on the adjacent forested uplands, (b) nearby winter icings resulting from artesian springs, (c) the relatively high pH, conductivity, calcium and magnesium concentrations of the water, (d) the vascular plant species composition and in particular the absence of Sphagnum moss, and (e) the flow of water and the geological history of the area. Expansion of these fens in several places is suggested by dead and dying white birch along the upland-fen margin, were permafrost thaw and subsidence (thermokarst) is taking place. Text permafrost Thermokarst Alaska Defense Technical Information Center: DTIC Technical Reports database Fairbanks |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Ecology Hydrology Limnology and Potamology *AERIAL RECONNAISSANCE CALCIUM WATER FLOW WATER ALASKA GEOLOGY GROUND WATER WINTER INTERNAL HISTORY WETLANDS VEGETATION SUBSURFACE SOUTH(DIRECTION) PH FACTOR FLOATING BODIES PERMAFROST MATS FAIRBANKS(ALASKA) PEAT GROUND LEVEL *ALASKA *WETLANDS *GROUND WATER *ENVIRONMENTAL IMPACT BOG AIR CUSHION VEHICLES INTERIOR ALASKA TANANA FLATS ALKALINITY BLADDERWORT WATER HEMLOCK BUCK BEAN SWAMP HORSETAIL SEDGES MARSH FIVEFINGER |
spellingShingle |
Ecology Hydrology Limnology and Potamology *AERIAL RECONNAISSANCE CALCIUM WATER FLOW WATER ALASKA GEOLOGY GROUND WATER WINTER INTERNAL HISTORY WETLANDS VEGETATION SUBSURFACE SOUTH(DIRECTION) PH FACTOR FLOATING BODIES PERMAFROST MATS FAIRBANKS(ALASKA) PEAT GROUND LEVEL *ALASKA *WETLANDS *GROUND WATER *ENVIRONMENTAL IMPACT BOG AIR CUSHION VEHICLES INTERIOR ALASKA TANANA FLATS ALKALINITY BLADDERWORT WATER HEMLOCK BUCK BEAN SWAMP HORSETAIL SEDGES MARSH FIVEFINGER Racine, Charles H. Walters, James C. Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska |
topic_facet |
Ecology Hydrology Limnology and Potamology *AERIAL RECONNAISSANCE CALCIUM WATER FLOW WATER ALASKA GEOLOGY GROUND WATER WINTER INTERNAL HISTORY WETLANDS VEGETATION SUBSURFACE SOUTH(DIRECTION) PH FACTOR FLOATING BODIES PERMAFROST MATS FAIRBANKS(ALASKA) PEAT GROUND LEVEL *ALASKA *WETLANDS *GROUND WATER *ENVIRONMENTAL IMPACT BOG AIR CUSHION VEHICLES INTERIOR ALASKA TANANA FLATS ALKALINITY BLADDERWORT WATER HEMLOCK BUCK BEAN SWAMP HORSETAIL SEDGES MARSH FIVEFINGER |
description |
In the northwest corner of the Tanana Flats, a lowland basin just south of Fairbanks in interior Alaska, there is a vast network of floating-mat wetlands or fens that appears to be unique in terms of their origin, large areal extent, and absence of sphagnum moss and associated peat. During the summers of 1989 and 1990 a study of the impacts of airboats on these wetlands included aerial and ground reconnaissance of 20 sites to characterize the vegetation, hydrology and subsurface conditions. These wetlands consist of a floating vegetation mat up to 1 m thick, forming an almost complete cover over deeper water bodies. The mats consist of a tall, dense and productive network of emergent vascular plants, including buckbean (menyanthes trifoliata), swamp horsetail(Equisetum fluviatile), sedges (Carexaquatilis), marshfivefinger(potentilla palustris),water hemlock (Cicuta mackenzieana) and bladderwort (Utricularia sp.). Evidence that these wetlands are formed by groundwater discharge includes (a) the apparent absence of permafrost under these wetlands but its presence on the adjacent forested uplands, (b) nearby winter icings resulting from artesian springs, (c) the relatively high pH, conductivity, calcium and magnesium concentrations of the water, (d) the vascular plant species composition and in particular the absence of Sphagnum moss, and (e) the flow of water and the geological history of the area. Expansion of these fens in several places is suggested by dead and dying white birch along the upland-fen margin, were permafrost thaw and subsidence (thermokarst) is taking place. |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Racine, Charles H. Walters, James C. |
author_facet |
Racine, Charles H. Walters, James C. |
author_sort |
Racine, Charles H. |
title |
Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska |
title_short |
Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska |
title_full |
Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska |
title_fullStr |
Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska |
title_full_unstemmed |
Groundwater-Discharge Wetlands in the Tanana Flats, Interior Alaska |
title_sort |
groundwater-discharge wetlands in the tanana flats, interior alaska |
publishDate |
1991 |
url |
http://www.dtic.mil/docs/citations/ADA241282 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA241282 |
geographic |
Fairbanks |
geographic_facet |
Fairbanks |
genre |
permafrost Thermokarst Alaska |
genre_facet |
permafrost Thermokarst Alaska |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA241282 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766165757381574656 |