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Cold Grassland

Maps and Photos of cold grassland range type
 

Cold Grassland Climatic Overview

Adak, Alaska is located on the Aleutian Chain.  The buffering effects of the ocean can be observed in both the climate and the vegetation.  Oceanic effects cause the average temperature to drop very slightly below freezing in the winter months, and to mediate the summer monthly temperatures. As a result, the mean summer and winter temperatures differ by less than 12°C.  The average temperature is about 5°C (41°F), and while annual precipitation can be within the 1500mm (59 in.) range (easily within forest requirements), the predominant vegetation type is characterized as a cold grassland.  This is due to low annual temperature, harsh conditions, and poorly developed soil profile, making the area unsuitable for tree growth.  The soil type of the area is volcanic, making it an andisol, with inceptisol and mollisol constituents.  Thus, while precipitation levels alone might support a forest in Adak, temperature and soil type dictate a cold grassland vegetation profile.

Cold Grassland Soils

According to Holechek, Pieper, and Herbel (2004), grassland supporting soils are most commonly mollisols. Yet they categorize nearly all of Alaska (excluding portions of south central and the extant of south east) as composed of inceptisols, which are young underdeveloped soils.  This is predominantly due to the long cold Alaskan winters, when weathering of the soil profile is low, and there is little or no vegetative growth.  The Aleutian Islands are also prone to stormy weather, in which soil richness can be leached out through excessive rainfall (erosion), and top layers can be blown away by high winds.  Soils of volcanic origin are most often classified as andisols.  The Aleutian Chain is composed almost entirely of volcanic islands, and seismic activity is high as the Aleutians span the subduction zone of the Pacific Plate (Ping, et.al. 1998).  Soil parent material is volcanic in origin, mostly agglomerate and ash (Kellogg et al, 1951).  Andisols are formed from the weathering of pyroclastic materials such as ash, pumice, cinders, and lava.  As this material is ‘softer’ (more easily weathered) than other types of rock, andisols form relatively faster than other soil types with a more durable parent material.  Alaska’s andisols are often cryands, meaning they have a cryic (cold) temperature regime.  However, over years of growth vegetative organic matter builds in the soil profile, and grasses are often associated with the formation of mollisols, as they add a great deal of vegetative matter to the soil.  It is therefore also plausible that the soil in the Adak area has gained nutritive richness under the grassland areas, in which case the soil profile would be headed toward a richer, more nutritive mollisol rather than the parent andisols and inceptisols.

Vegetative Community of the Cold Grassland Range Type

Obviously, the vegetation types in a cold grassland are cold tolerant species, and in general these tend to be long lived and show slow growth.  The vegetation on Adak reflects this: there are few trees, and the landscape is dominated by grass and rush species, as well as some other herbaceous species (Talbot, 1994).  Of the few trees on the island, many have been planted as ornamentals (sitka spruce (Picea sitchensis), for example).  Grasses and herbaceous plants consist of predominantly tall grass (Elymus spp.), and some cotton-grass rushes.  Herbacious plants include fireweed (Epilobium angustifolium), monkshood (Aconitum spp.), and other cold-tolerant species (Van Hees, 1999).  There are also many endemic species of interest to botanists, as the geographical isolation of the area can result in speciation and/or preservation of species not found elsewhere in Alaska.  Vegetation in Adak must be tolerant of cold, high rainfall, and stormy, windy weather.  Any plant species in close proximity to the ocean also must be tolerant of oceanic effects of fog and, in some cases, even salt water spray and mist.  The islands are also volcanic, so the parent material of the soil is most likely of volcanic origin, and plants must be able to cope with this soil type.  Both andisols and inceptisols don’t hold water, but this is not an issue in an area receiving Adak's amount of rainfall.  The temperature regime of the area never really warms throughout the summer months, and winter month temperatures are rarely below freezing; meaning that while plants have to cope with the cold summer, they are relieved from a bitterly cold winter.  There is never a dry period, and rainfall is high enough and consistent enough for the top soil layers to be wet constantly.  There is also a high occurrence of fog, another source of vegetation moisture.

Current Uses of the Cold Grassland

There are many uses of the cold grasslands and the rivers that run through them year round.  The economic basis of the communities in the cold grasslands relies heavily on subsistence hunting and gathering activities.  Many different “species of salmon have spawning beds on the various tributaries of the Kuskokwin River, like King salmon, chum salmon, red salmon, are dried on outdoor fish drying racks after having been split and sliced to promote drying” (Williams 2003).  Many small animals like “beaver, muskrat, snowshoe hare, mink and otter are harvested both for their meat and their skins” (Williams 2003).  In March Ptarmigan are hunted, “when they forsake a solitary lifestyle and begin to gather in large flocks” (Williams 2003).  There are many types of wild berries to harvest from mid July through September, like “blueberries Vaccinium uliginosum, crowberries Empetrum nigrum, and cranberries Vaccinium vitis idaea.  Other wild plants harvested include wild rhubarb Polygonum alaksanum, cow parsnip Heracleum lanatum, wild celery Angelica lucrda, and Labrador tea Ledum palustris ssp groenlandicum” (Williams 2003).  Both subsistence and sport hunting are abundant with “moose, caribou, black bear, brown bear, muskox is found in the delta area” (Rosiers 2003).  Many families use this large game to fill their freezers.

Winter sports are abundant in the cold grasslands like “cross country skiing and snow machining” (Rosiers 2003).  Sled dog racing or for fun is also a great sport for winter.  “Experienced musher’s race from Bethel to Anrk and back in the annual Kuskokwin 300 Sled Dog Race” (Thompson 2003).  As you can see there are many activities, both for survival and pleasure that can be had on cold grasslands.

Future Concerns

The cold grasslands are a delicate habitat with many microhabitats working together.  Within all of these habitats are humans that seem to create problems in habitats like the cold grasslands.  One of the problems is the steady increase of landfills around these small communities.  The Bethel Recycling Center has proposed making pressed fire logs from wood and paper landfill waste.  “The landfill study estimates that paper and wood products make up 47% of the solid waste in the landfill” (Grover 2003).  By making fire logs they could reduce the volume in the landfill “by 10% to 20% through the recycling project” (Grover 2003).

Hovercrafts have been making their way up the rivers in winter to Bethel and other communities, to bring supplies and mail.  This winter a vehicle weighing 30 tons and 70 feet long makes its way up frozen rivers.  Concerns have been raised “by villagers that the high speed craft could cause environmental problems by frightening birds and disrupting fish spawning beds” (Howk 2003).  Also other concerns are the noise and air pollution of the four diesel engines that run the hovercraft.  The owners of the hovercraft are aware of these concerns and are trying to work with villagers to have the least amount of impacts on this area.

Global warming is a great concern these days in the world and also in the cold grasslands.  “Thawing and melting are likely to bring widespread changes in ecosystems, increase erosion, harm subsistence livelihoods, and damage to buildings, roads and other infrastructures” (ERRP 2003).  From permafrost thawing it could cause destruction of trees in boreal forest “expansion of thaw lakes, grasslands and wetlands” (ERRP 2003).  This would take habitat away from some species and give it to the other species.  It’s important to realize now what changes are going to be happening in the future and to prepare for them now, not later.

By Kari Maakestad and Richard Ranft
(editorial revision by John Kawula)

References

Soils

Holechek, J.L., Pieper, R.D., & Herbel, C.H. (2004). Range Management Principles and Practices. 5th Ed. Upper Saddle River, N.J., Prentice Hall, pp. 51-83.

Kellogg, C.E.,  Nygard, I.J. (1951) Exploratory Study of The Principal Soil Groups of Alaska. (U.S. Dept of Agriculture. Agriculture Monograph, no. 7). Washington, D.C., [U.S. Government Printing Office].

Ping, C.L., Shoji, S. & Ito, T. (1998). Properties and Classification of Three Volcanic Ash Derived Pedons from Aleutian Islands and Alaska Peninsula, Alaska. Soil Science Society of America Journal. 52(2) March/April, pp. 455-462.

Vegetation

Heusser, C.J. (1990). Late Quaternary Vegetation of The Aleutian Islands, Southwestern Alaska. Canadian Journal of Botany. 68(6) June, pp.1320-1326.

Talbot, S.S. u. U.S. Fish and Wildlife Service, Anchorage AK, & Talbot, S.L. (1994). Numerical Classification of the Coastal Vegetation of Attu Islands, Aleutian Islands, Alaska. Journal of Vegetation Science. 5(6) December, pp.867-876.

Van Hees, W.W.S. (1999) Vegetation Resources Inventory of Southwest Alaska: Development and Application of an Innovative Extensive Sampling Design. (Research Paper - PNW-RP-507). Portland, OR, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. pp. 1-51.

Current Uses

Rosiers, M. 2003. A Profile of Bethel.  http://www.cbna.info/village/bethel/bethel.html. 22 April 2005.

Thompson, D. 2003. The Milepost Event Calendar. http://www.alaskamagazine.com/events/index.shtml. 22 April 2005.

Williams, Z.J. Community. 2003. http://www.lksd.org/napaskiak/community.htm. 22 April 2005.

Future Concerns

Educational Resourses Regional Paper: Alaska. 2003. US National Assessment of the Potential Consequences of Climate Variability and Change. http://www.usgcrp.gov/usgcrp/nacc/education/alaska/ak-edu-5.htm. 22 April 2005.

Grover, J. 2003. Recycling program could mean warmer homes in Bethel. Tundra Drums News. http://www.kusko.net/z_artcle_261.shtml. [Not available via Internet address 19 April 2005.  The date and page of the article are unverifiable.  The newspaper office must be contacted to obtain the correct citation.]

Howk, R. 2003. Hovercraft turns a profit delivering mail to Bethel area. Alaska Journal of Commerce. http://www.alaskajournal.com/stories/111703/loc_20031117025.shtml. 22 April 2005.