The Coastal Tundra 

 at Barrow 



J. Brown, K. R. Everett, P. J. Webber, 

 S. F. Maclean, Jr., and D. F. Murray 



THE ARCTIC COASTAL PLAIN: 

 A GEOGRAPHIC PERSPECTIVE 



The word tundra is broadly used to refer to the landscapes that are 

 found above the altitudinal or latitudinal treeline. The classification of 

 tundra has been reviewed by Barry and Ives (1974) and Murray (1978). In 

 Alaska, lowland tundra covers large portions of the Aleutian Islands and 

 the delta of the Yukon and Kuskokwim Rivers in the southwest, the Sew- 

 ard Peninsula in the west, and the Arctic Slope (see map inside front 

 cover). Alpine tundra is found in all the mountain ranges and at eleva- 

 tions above about 1000 meters in upland terrain such as the Yukon- 

 Tanana Uplands. 



The Arctic Slope, that part of northern Alaska that drains to the 

 Arctic Ocean, covers 200,000 km^ an area the size of the state of Nebras- 

 ka. It consists of three major physiographic provinces: the Brooks 

 Range, the Arctic Foothills, and the Arctic Coastal Plain (Figure 1-1). 

 These provinces differ in topography, geology, climate and history, and 

 consequently in fauna and flora. Permafrost underlies all land surfaces 

 at depths up to approximately 600 m. 



The Brooks Range, with peaks as high as 2700 m, has cirque glaciers 

 in its central and eastern sections. Variations in slope and topography 

 lead to large differences in microclimate and in soil properties, and thus 

 there are diverse habitats for plants and animals. Only the floodplains of 

 the larger river drainages have extensive stands of a single vegetation 

 community, usually shrub thicket. The valley bottoms contain sedge 

 meadows and well-developed shrub tundra that is dominated by willow 

 {Salix lanata, S. pulchra, S. glauca and S. alaxensis) and dwarf birch 

 {Betula exilis). The slopes have dry meadow or heath communities 

 dominated by Dryas octopetala. Above about 1800 m vascular plants are 

 limited to protected sites, and lichen cover is discontinuous. Such areas 

 are analogous to the polar deserts of high latitudes, and might be called 

 alpine deserts. 



I 



