SOME CHARACTERISTICS OF THE CLIMATE IN FOREST AND TUNDRA REGIONS IN ALASKA*

• Main Author: David M. Hopkinst
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Benninghoff; Arctic; Brooks Range; Kodiak; Tundra; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.509.9556; http://pubs.aina.ucalgary.ca/arctic/Arctic12-4-214.pdf

T HE present-day vegetation of Alaska consists of three major types: the coastal Sitka spruce-hemlock forest of southeastern and south-central Alaska; the interior white spruce-birch forest of central Alaska; and the treeless tundra of western and northern Alaska (Sigafoos 1958). All three vegetation types are represented by assemblages of fossil plant remains found in different strata of late Cenozoic age in western Alaska (Hopkins and Benninghoff 1953). A desire to assess the palaeoclimatic significance of these fossil plant assemblages led to the results that are presented here. The coastal forest extends a few tens of miles inland along the coast of southeastern and southern Alaska westward to Cook Inlet and north-eastern Kodiak Island (Fig. 1) the interior forest is distributed through most of central Alaska north of the coastal mountains and south of the Brooks Range; and the tundra is found beyond the continental limits of forest in central and western Alaska and in highland areas above the altitudinal limits of forest in central and southern Alaska. Both forest types contain several species of trees in addition to those employed here to characterize them (Sigafoos 1958), and the tundra is a mosaic of many different sorts of vegetation, some of which are limited to either southern or northern tundra regions (Griggs 1936, Hanson 1953, Britton 1957). The detailed boundary between forest and tundra is intricate and is determined by small differences in the character of the soil, drainage conditions, intensity of frost action, and perhaps microclimate (Sigafoos 1953). The detailed boundary between coastal and interior forest no doubt reflects similar minor variations in environmental conditions. In a few places in Alaska the boundaries between major vegetation units appear to be shifting actively and rapidly in response to recent small climatic changes (Griggs 1934). However, the data presented here suggest that in much of Alaska the gross boundaries between the three major vegetation types reflect regional ...