抄録
Cold regions are featured by most distinctive activities and developments conducted by mankind with much bearing on life. The aspects and concepts of the cold regions might be defined geographically for understanding the relation between human activities and physical environments. Coldness acts on the ground and vegetation in a long geological time. And the characteristic land forms have developed in those regions, while vegetation such as coniferous forests have adapted so well to the cold environments that they have dominated the regions.
This symposium was planned and organized with an aim to understand the characteristics of the cold regions from various viewpoints through interdisciplinary discussions. Those researchers who were invited to participate in it represented the fields of physical geography, plant ecology, glaciology and anthropology.
The symposium had the following five sessions with topics and speakers mentioned together:
I) Cold Regions location and definition in a global scale
* Cold regions defined by climatology, by Prof. M. Yoshino, of Tsukuba Univ.
* Cold regions characterized by forest ecology, by Prof. A. Sakai, of Hokkaido Univ.
II) Polar Regions
Glacial erosion and glacial fluctuations in Antarctica, by Prof. Y. Yoshida, of
* National Polar Research Institute
* Sea-ice and glaciers in polar regions, by Prof. K. Kusunoki, of the same
* Submerged topography near the coast of Showa Station Antarctica, and its relation with the advanced ice-sheet from inland, by Dr. K. Omoto, of Tohoku Univ.
III) Sub-Arctic Regions
* Regional distribution and characteristics of permafrost, by Prof. S. Kinosita, of Hokkaido Univ.
* Glacial and interglacial alternations in late Quaternary, by Dr. K. Hirakawa, of Yamanashi Univ.
W) Alpine Regions
* Characteristics of plant ecology in alpine regions, by K. Dr. Ito, of Hokkaido Univ.
* Characteristics of alpine regions in Japan compared with other alpine regions, by Dr. T. Koizumi, of Tokyo Gakugei Univ.
V) Climatic Changes
* Climatic changes in cold regions, by Prof. Y. Sakaguchi, of Tokyo Univ.
* Climatic changes and their impacts on human history, by Prof. K. Okada, of Hokkaido Univ.
* Paleo-environments in coastal regions in Hokkaido in the post last glacial age, by Dr. K. Endo, of Nippon Univ.
Session I started with Prof. Yoshino's introduction of a variety of classifications of cold regions from the viewpoint of climatology. He pointed out the index of a warmer period such as the monthly mean air temperature of the warmest month during the year, which was the most suggestive in the definition of the cold regions. Then, Prof. Sakai indicated that coniferous forests dominate the cold regions, such distributions of the trees being due to accumulating temperatures during the growing period and to their dormance during the cold period. Besides these thermal conditions, precipitation is also important, he said, adding that boreal forests in the cold regions adapt to the physical environments characterized by coldness and precipitation such as above and that as the results of adaptation, the number of tree species is smaller in the warmer regions.
Session II began with Prof. Yoshido's explanation of the characteristics of land forming process in Antarctica. He also pointed out that glacial erosion dominates in Antarctica, because other fluvial erosions do not occur. In his talk, however, the intensity of the erosion was not examined in detail. Next, Prof. Kusunoki showed the paleo-climatic records obtained from ice-core samples from the Antarctica ice-sheet. He also explained the importance of the sea-ice coverage along the Antarctical Coast resulting in the global climatic changes.
