General northward displacement of all climatic zones in the Hypsithermal is infered from various field data from many parts of the World. This is consistent with my previous discussion on the Würm climate done in the Bulletin of the Department of Geography, University of Tokyo, under the title “Climatic Zones in the Würm Glacial Age” which appeared in 1971. The content of this report will appear in English also in the same Bulletin in March, 1975.
Pollen records and archaeological data during the last 12, 000yrs. in Japan are analysed to discuss some of the inter-relationships between human activities and changing vegetation. 1) Geographical distributions of cultural areas, known from the regional variation of Jômon pottery, were directly correlated to the vegetational changes known through pollen analysis. At colder and cooler climatic periods (pollen zone, L·RI·R III a, ) two cultural areas showed strong contrast between northern and southern Japan. While in a warme climatic period (pollen zone, R II, ) this contrast was weakend. The cultural areas of this period can be subdivided further into seven smaller areas. Relationships between vegetation and culture are illustrated by Fig. 5, 6, 7 and 8. It is evident that the prehistoric human occupation was strongly influenced by the vegetational change. 2) Prehistoric and historic clearance of forest and agriultural activities by man are recognizable on pollen diagrams. The frequencies of forest clearance and their amounts varied from place to place and from time to time. It is infered that forest clearance by Neolithic man of Jômon Age was rather small in scale and temporary. The clearance during Yayoi Age became far more intensive and probably more prolonged than previous Jomon age in southern Japan. However, regional variation in the pollen records are found during this age. In northern Japan, there were less intensive agricultural activities and no extensive clearance was done until much later.
Six different types of molluscan assemblages are recognized in the Holocene littoral deposits, accumulated during the Climatic Optimum (5, 000-6, 000y. B. P.), along the Pacific coast of Japan. These assemblages are typically observed in the Holocene embayment deposits of the Paleo-Ohuna Bay in central Honshu (Lat. 35°N). They are found from several embayment deposits distributed between Okhotsk coast of northern Hokkaido (Lat. 45°N.) and western Kyushu (Lat. 33°N.), although their existence and local distribution within each embayment were controlled by topography of the bay and bottom sediments. The assemblages are composed mainly of the warm water species, intermixed with some cold water elements in the northern areas. The northern limits of the distribution of constituting species were located further north than those of the living species. The northward extension of distribution was remarkable in northern Hokkaido. Along the Okhotsk coast of northern Hokkido, the littoral molluscas, whose present day analogs are living in the area south of north Honshu (Lat 41°N.), were found constituting shell beds in the Holocene deposits, and also found from the shell mound in the Early Jomon era. In this area the minimum temperature of surface water at the Climatic Optimum was estimated to be about 5°C higher than at present when compared with the water temperature of northern Honshu. The southern end of the cold water species distribution is recognized in the Sendai area (Lat. 38°N.), where the warm water assemblages are intermixed with the cold water elements. Marine condition of this area was presumably similar to that observed at present in the area off Choshi, central Japan (Lat. 36°N.). The distribution of warm water species at the time of Climatic Optimum is shown in Figure 13. Estimated minimum surface temperatures are also shown in this figure. The temperature difference between the Climatic Optimum and the present becomes less conspicuous toward the south.
Adaptation of Jomon people in the Japanese islands attained a certain level in the course of history between the stage 3 and 4 of Jomon Age which is divided into six stages. Cultural areas at that time can be divided into eight groups (see Fig. 1). These were I) Hokuto cultural area in the subarctic needle-leaf forest of eastern Hokkaido, II) Ento cultural area in the cool-temperate deciduous forest of southwestern Hokkaido and northern Tohoku, III) Daigi cultural area in the warm-temperate deciduous forest along the rias coast of southern Tohoku, IV) Ukishima-Otama cultural area in the evergreen broad-leaved forest of eastern Kanto where the coastal line was extensively elongated by the Jomon transgression, V) Umataka-Chojagahara cultural area in the warm-temperate deciduous forest on the Japan Sea slope where the winter snow is thickest in Honshu, VI) Katsusaka cultual area in the warm-temperate evergreen broad-leaved and deciduous forest on the Pacific slope, VII) Funamoto cultural area in the evergreen broad-leaved forest of western Japan and VIII) Sobata-Ataka cultural area in the evergreen broad-leaved forest of western Kyushu. Due to the adaptation to such natural environments these eight cultural areas showed great regional varieties. Locating in the northern side of the Blakiston line, Hokkaido had particularly different cultures. Differnt kinds of bears lived there and no wild pig was found. Accoridingly stone arrow-head showed larger percentage than stone spear-head increasingly in the north. Also the fishing cultures were different in Hokkaido where the cold ocean currents were dominant. In Honshu along which the warm ocean current were prevailing, Daigi cultural area was a center for fishery in ocean (fish-fook and harpoon for Chrysophrys major, Thunnus thynnus, Katsuwonus pelamis etc.) and Ukishima-Otamadai culural area was a center for fishery in bay (netsinker and bone fish-spear for Lateolabrax japonicus, Mylio macrocephalus etc.). Incipient agricultre is often discussed for the Katsusakac ultural area. Also wild nuts had regional differenciation. Nuts of Lepidobalanus were found from the cultures I)-VI), while those of Cyclobalanopsis and Passania were for the cultures IV)-VIII). Aesculus trubinata were common to II)-VI). Distribution of stone querns etc. had certain relationships with these nuts. The adaptation patterns, however, were quite complicated and it will take long time to reconstruct the whole adaptation systems. Cooperation with the related sciences is strongly needed.