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Tundra
Barren Tundra
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of barren tundra range type
Barren Tundra Climatic Overview
Barren tundra is characterized by a low mean annual
precipitation of 357mm (14 in.) and low mean annual temperature of
-5°C (-0.2°F). Most precipitation occurs from June to
September, often peaking in August. Despite low precipitation,
permafrost prevents much water from moving into the ground, and low
temperatures slow evaporation, resulting often in seasonally wet
sites. As microtopography affects soil moisture, it is another
important factor in predicting vegetation. Low sites are generally wet,
and high sites are generally dry. Each
moisture type supports a different community of vegetation. Although
the tundra is usually wet in the summer, useable water is unavailable,
as it is
frozen most of the year. As a result, vegetation and lichen
present must be drought tolerant. Soils in this area are characterized
by the presence of permafrost, decreased decomposition due to low
temperatures, and seasonal freezing and thawing that prevents much
horizon development.
Barren Tundra Soils
Tundra soils are gelisols (Harris 2004a). Gelisols
have permafrost (permanently-frozen ground) within two meters of the
ground’s surface. Mineral soil is directly
above the permafrost. Organic debris, provided by tundra plants and
animals, accumulates into an active layer above the mineral soil.
Tundra soils are able to store large amounts of carbon due to low
temperatures and water logging (MacLean 1996, online). Soil horizons
are not well developed due to freezing and thawing that
occurs in the warm season (Smith 2001). Brown and Hinkel (Circumpolar
Active Layer Monitoring 2003, online) found the maximum depth that soil
thawed over permafrost averaged 55cm (21.7 in). This thawing “allows
root penetration, growth and nutrient uptake by tundra vegetation
(Massachusetts Institute of Technology 2004, online).”
Barren tundra consists of 17.9 % Histic Pergelic
Cryaquepts-Pergelic Cryofibrists-Pergelic Cryaquepts, 15.8 % Rough
Mountainous Land, 11.0 % Pergelic Cryaquepts-Pergelic
Cryopsamments-Histic Pergelic Cryaquepts and 6.5 % Pergelic
Cryaquolls-Histic Pergelic Cryaquepts-Pergelic Ruptic-Histic Cryaqu
(Harris 2004b).
Histic Pergelic Cryaquept soils are found in lowlands
and are made up of partially decomposed organic matter that grades into
dark green-gray silt loam. Pergelic Cryofibrist soils are
poorly-drained and have an organic component that consists of sedge and
moss peat. Pergelic Cryaquepts soils are found in lowlands, flood
seasonally and have a shallow surface layer of “partially decomposed
organic matter” that grades into dark gray sandy loam.
Histic soil is “shallow with poorly aerated organic
material (Massachusetts Institute of Technology 2004, online).”
Pergelic soil has permafrost present due to having “mean annual soil
temperatures of less than 0º C (The University of Arizona Library
2004, online). Aquept “suggests poor drainage (Massachusetts Institute
of Technology 2004, online).”
Vegetative Community of the Barren Tundra Range Type
Arctic tundra does not have a unique vegetation type.
“Structurally the tundra is a grassland and mixed shrubland (Smith
2001).” Temperature is the primary factor determining what
plants grow in the arctic. Secondary factors include soil moisture
and soil fertility. “The wetness of the soil is controlled by the
microtopography of the land much more than by annual precipitation.”
This is because permafrost prevents rain and meltwater from moving into
the ground. In addition, evaporation is slowed by low temperatures
(Pielou 1994).
Low wet areas are dominated by tussock-forming sedges
and contain “dwarf heath, and a sphagnum moss complex (Smith 2001).”
Additional mosses found on wet soil include Aulaomnium, Ditrichum and
Calliefgon (Bliss 1988 cited in Hagenstein et al. 2001, online).
Species that appear on well-drained sites include a
low shrub -- dwarf arctic birch (Betula nana)-- and heath shrubs
-- crowberry (Empetrum nigrum), narrow-leaf Labrador-tea (Ledum
decumbens), mountain-cranberry (Vaccinium vitis-ideaea)
(USGS 2004, online) (Smith 2001). “Mosses (e.g., Hylocomium
splendens and Sphagnum spp.) and lichens (e.g., Cetraria
cucullata, Cladonia spp., and Cladina rangiferina)
are common between tussocks (USGS 2004, online).”
Driest sites are usually those with relatively high
elevation. The surface there is often rocky and exposed
to frost action. “Plant cover consists of scattered heaths and mats of
mountain avens (Dryas), saxifrages (Saxifragaceae), and other cushion
plants….”
Relatively warm south-facing slopes support tall
shrubs, grasses and legumes. “Cottongrass (Eriophrum angustifolium)
dominates the gentle north-facing and south-facing slopes, reflecting
the higher air and soil temperatures and greater snow depth (Smith
2001).”
Current Uses of the Barren Tundra
Current land uses on the tundra include subsistence
hunting, commercial hunting, energy extraction, scientific research,
recreation and use by wildlife. The North Slope Borough has a resident
population of 7,500 people (Alaska Department of Labor and Workforce
Development, 2000). In Alaska, in general, sport harvest is greater in
areas with roads, and subsistence harvest is greater in areas without
roads. Rural households that are most successful at subsistence hunting
usually include mature parents and many adult children. Harvested goods
are generally shared with others in the community. Fish is the main
subsistence food in Alaska (Wolfe 1989). However subsistence hunting in
Alaska can involve harvesting wildlife such as caribou, moose, whales
and waterfowl (Kofinas 1993). Plant products are also gathered and used
(Wolfe 1989). Arctic Village harvests an estimated 521.1 pounds of wild
food per person per year, and Kaktovik harvested 885.6 pounds of wild
food per person in 1992 (Wolfe 2004). Subsistence hunting has cultural
significance in addition to being an important part of the rural
economy (Kofinas 1993).
Oil was discovered in Prudhoe Bay in 1968. Alaskan
employment in the oil industry peaked (10,700 people) in 1991. Prudhoe
Bay employed 6,063 people in 2002, and the oil industry employed 8,800
people in Alaska in 2002 (Freid 2003). The Alaska Native Claims
Settlement Act (1971) was a land transaction that involved industry,
environmentalists and Native Alaskans. The act enabled a consortium of
oil companies to build the 789-mile Trans Alaska Pipeline (DuFrense
2003).
Future Concerns
Future concerns about the barren tundra include oil
development of the Artic National Wildlife Refuge and effects of global
climate change. Proponents of drilling in the Arctic Refuge list some
of the following reasons in favor of drilling: 1) Less than 10 % of the
refuge would be considered for drilling; 2) Drilling could generate
billions of dollars for state and federal treasuries; 3) New jobs in
Alaska and in other states would be created (Arctic Power 2004).
However, in 1999 two thirds of Americans did not want drilling to occur
in the Arctic Refuge. The area under consideration is the calving
ground for the Porcupine Caribou Herd, and the coast provides
terrestrial denning sites for polar bears (Defenders of Wildlife 2004).
Global climate change is occurring, and the arctic is
warming faster than the rest of the earth. Average annual temperatures
in the arctic have increased at almost twofold the rate of the rest of
the world over the last few decades. The arctic is particularly
vulnerable to the impact of climate change. Many coastal villages may
face increased erosion as sea level rises and sea ice diminishes.
Temperatures of permafrost have increased (up to 2°C in some areas)
in the last few decades. In many areas the active layer depth is
increasing. Tundra soils store a significant amount of the earth’s
terrestrial-based carbon. Ground thawing will likely impact arctic
transportation, industry and infrastructure. Shorter frozen periods
will reduce the time in which ice and snow enable easier transport over
the tundra and its waterways (Hassol 2004).
By Kim Fackler
(editorial revision by John Kawula)
References
Soils
CIRCUMPOLAR ACTIVE LAYER MONITORING 2003. Circumpolar
Active Layer Monitoring (CALM) Network. University of Cincinnati.
[On-line] Available from http://www.geography.uc.edu/~kenhinke/CALM/sites.html
13 Nov. 2004.
HARRIS, N., 10 September 2004a. Physical
Characteristics of Rangeland lecture, NRM 312 Introduction to Range
Management, University of Alaska Fairbanks [handwritten notes].
Unpublished.
HARRIS, N., 13 October 2004b. The Main Ten Statsgo
Soils for Each Range Type, NRM 312 Introduction to Range Management,
University of Alaska Fairbanks [Range_types_soils.doc, Bb Blackboard
University of Alaska Fairbanks, Introduction to Range Management].
Unpublished.
MACLEAN, R., SCHIMEL, J., DOYLE, A., 1996. Active
Pools of Carbon and Nitrogen in Soils of the Alaskan Tundra..
Department of Biology and Wildlife, Institute of Arctic Biology,
University of Alaska Fairbanks. [On-line] Available from http://www.cgc.uaf.edu/newsletter/carbon.html
21 Dec. 2004.
MASSACHUSETTS INSTITUTE OF TECHNOLOGY,. no date. Mission
2007 Environment. Massachusetts Institute of Technology. [On-line]
Available from http://web.mit.edu/12.000/www/m2007/teams/finalwebsite/environment/phyenv_soil.html
19 Oct. 2004.
SMITH, R.L. AND SMITH, T.M., 2001. Ecology &
Field Biology. 6th ed. San Francisco: Benjamin Cummings.
THE UNIVERSITY OF ARIZONA LIBRARY., no date. Books
of the Southwest University of Arizona. [On-line] Available from http://southwest.library.arizona.edu/azso/back.1_div.6.html19
Oct. 2004.
Vegetation
BLISS, L.C., 1988 cited in HAGENSTEIN, R., SIMS, M.,
MANN, G., RICKETTS, T., 2001. Arctic Coastal Tundra (NA1103)
World Wildlife Federation. [On-line] Available from http://www.worldwildlife.org/wildworld/profiles/terrestrial/na/na1103_full.html
19 Oct. 2004.
HAGENSTEIN, R., SIMS, M., MANN, G., RICKETTS, T.,
2001. Arctic Coastal Tundra (NA1103) World Wildlife Federation.
[On-line] Available from http://www.worldwildlife.org/wildworld/profiles/terrestrial/na/na1103_full.html
19 Oct. 2004.
PIELOU, E.C., 1994. A Naturalist’s Guide to the
Arctic. Chicago: The University of Chicago Press.
SMITH, R.L. AND SMITH, T.M., 2001. Ecology &
Field Biology. 6th ed. San Francisco: Benjamin Cummings.
USGS., no date. Alaska Ecoregions Arctic Foothills.
USGS. [On-line] Available from http://www.ofps.ucar.edu/atlas/ivotuk_CD/reports/ecoregions.htm
19 Oct. 2004.
Current Land Use
ALASKA DEPARTMENT OF LABOR AND WORKFORCE DEVELOPMENT,
2000. Alaska Population Overview: 1999 Estimates. Alaska:
Alaska Department of Labor and Workforce Development, Research and
Analysis Section, Demographics Unit.
DUFRESNE, J., PENLAND, P.R., ROOT, D., 2003. Alaska
(7th ed.). Oakland, CA.: Lonely Planet Publications.
FREID, N., WINDISCH-COLE, B., September 2003. The
Oil Industry. Alaska Economic Trends. [On-line] Available from http://www.labor.state.ak.us/research/trends/sep03ind.pdf
12 Dec. 2004.
KOFINAS, G., 1993. Subsistence Hunting in a Global
Economy. Contributions of Northern Wildlife: Co-Management to
Community Economic Development. Institute of Arctic Studies at
Dartmouth College. [On-line] Available from http://arcticcircle.uconn.edu/NatResources/subsistglobal.html
9 Dec. 2004.
WOLFE, R., 1989. Frequently Asked Questions:
Myths; What Have You Heard? Subsistence Division-Alaska Department
of Fish and Game. [On-line] Available from http://www.subsistence.adfg.state.ak.us/geninfo/about/subfaq.cfm#q3
10 Dec. 2004.
WOLFE, R., no date. Wild Food Harvests in Alaska,
Nutritional Contributions Sorted by Harvest and by Place.
Subsistence Division- Alaska Department of Fish and Game. [On-line]
Available from http://www.subsistence.adfg.state.ak.us/download/nutri97.pdf
18 Apr. 2005.
Future Concerns
ARCTIC POWER., no date. Top 10 Reasons To Support
Development In ANWR. Arctic Power. [On-line] Available from http://www.anwr.org/topten.htm
12 Dec. 2004.
DEFENDERS OF WILDLIFE., no date., Arctic National
Wildlife Refuge. Defenders of Wildlife. [On-line] Available from http://www.defenders.org/wildlife/arctic/arissue.html
12 Dec. 2004. [URL no longer available 18 April 2005.]
HASSOL, S.J., 2004. Impacts of a Warming Arctic:
Arctic Climate Impact Assessment. Cambridge, United Kingdom.
Cambridge University Press.
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