I N northern lands special problems presented by frost in soils are receiving more and more attention as the pace of construction and settlement increases. Investigations aimed primarily at these problems, notably that of permafrost, have partially revealed the composition and mechanisms of the seve...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.495.4189 http://pubs.aina.ucalgary.ca/arctic/arctic5-1-34.pdf |
| Summary: | I N northern lands special problems presented by frost in soils are receiving more and more attention as the pace of construction and settlement increases. Investigations aimed primarily at these problems, notably that of permafrost, have partially revealed the composition and mechanisms of the severe frost climate1 environment. Parts of this environment owe their nature to the influence of vegetation and soil frost2 on each other. In temperate climates the effects of soil frost on plants are so seldom observable that they have been studied in special cases only. In the severe frost climates of high latitudes, and in similar climates at high altitudes, perennially frozen ground and intensive frost action are primary environ-mental factors in the development and existence of individual plants and of plant communities. Similarly, the fact that penetration of seasonal frost is influenced by vegetation cover is con-imon knowledge in temperate regions but has not required special study. In the severe frost climates, however, plants both individually and collectively strongly modify the occurrence and work of soil frost. This interaction is the basic mechanism of a dynamic soil-vegetation system in severe frost climates. Undoubtedly these forces are now at work to some degree in the mid-latitudes, but the effects are too slight or too local to have received special attention. Much evidence is being produced to show that intensive frost action exerted strong effects in the mid-latitudes during the Pleistocene glaciations, leaving behind soil features that still have expression in many landscapes (Denny, 1938; Smith, 1949; Raup, 1951). In northern regions, such as Alaska, knowledge of soil frost phenomena and their inter-action with vegetation is vital to an understanding of soils, vegetation, and landforms. Influence of soil frost on plants The frozen condition of a soil must exert direct effects upon the plant roots contained in it, but the exact effects are little known as most studies |
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