Proceedings of the General Meeting of the Association of Japanese Geographers

Lake Jinzai is a small brackish water lake which locates in the southwestern part of the Izumo Plain, Shimane Prefecture, western Japan. The JZ-01 sediment core was taken at the center of the lake by the thin-wall type piston core sampler. The core length is 24.3 m. This study clarified the stratigraphy and sedimentation rates in the JZ-01 core on the basis of initial description and eleven AMS radiocarbon dating of organic materials and shell fragments. And it could reconstruct detailed Holocene environmental changes from the records of mineral and main chemical composition analyses. The water condition changes at Lake Jinzai was presented by the variable authigenic iron minerals as Pyrite, Marcasite and Siderite contents and the sulfur content of the sediment as a proxy. The results demonstrate that lake water condition have drastically changed through the Holocene with the periods of the brackish water condition from 9,500 to 7,300, 4,100 to 1,900 and refer to 400 cal. yr B.P. at Lake Jinzai. Also the influence of human impacts to the lake began to since 2,000 cal. yr B.P. which might be related to the formation of ruins in the Ancient Izumo Kingdom.

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The natural range of coast redwood(Sequoia sempervirens) extends only along the Pacific Coast from south Oregon to central California in the world. Redwood trees on alluvial flats have tall height more than one hundred meters, and this species has longevity. One of the ecological characteristics is what the regeneration is related to disturbances.
Because three tectonic plates known as the North American, the Pacific, and the Gorda contact each other at the Mendocino triple junction, the North Coast region is the most seismically active region in the United States, therefore rapid uplift rates have led to landslides, actively braiding and shifting rivers, and rapid coastal erosion.
Results from the studies of the redwood distribution based on geological characteristics of northern California and ecological characteristics of redwood led to the hypothesis: the distribution of redwood forest appears the ancient alluvial flats, that is, the establishment of the distribution of redwood forest is related to the geomorphologic development, particularly river shifting due to uplift in that region. To verify this hypothesis, the genetic and geomorphologic studies have been done in this study: 1) to examine the relationship between the distribution of redwood and the extent of fluvial deposit, observation of the superficial condition has been done in the range, besides, geomorphologic maps were made out to examine the character of the landform in both redwood area and non-redwood one. 2) to examine the extent of genetic variation within and among populations and among watersheds of rivers in the range of the distribution of coast redwood, AFLP (Amplified Fragment Length Polymorphism)analysis is applied to 11 populations 129 samples in the whole range.
As to the results of geomorphic study, the distribution of redwood is related to the areas covered with fluvial deposits in the north part of redwood region, though the south part has little correlation. From the geomorphologic maps, the characteristics are observed that the area with redwood has flat surfaces on the slopes, while non-redwood area has little. As a result of AFLP analysis, a total of 335 fragments were detected using on selective primer pairs(EcoRI+AAG/MseI+CCCAG). In this first AFLP study of coast redwood, high levels of genetic variation within population were observed by AMOVA(Analysis of Molecular Variance). These high levels might be related to this species'hexaploid condition. Populations on the floodplain inclined to more polymorphic than populations in upland sites. Genetic structures among population and among watershed were little detected.

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In recent years, the number of foreign tourists to japan has increased. The Japanese government has started a campaign (Visit Japan Campaign) to promote international tourism to Japan/ There are few data available about the destinations of foreign tourists in Japan, but the JNTO states that 56.5% of foreigners arriving in Japan visited Tokyo, 25.2% Osaka, 15.8% Kyoto, 15.6% Kanagawa, so generally, there is a trend to visit the conurbations centering on Tokyo, Osaka and Nagoya. As a result, although foreign tourists can be encountered in all parts of the country, there are very few destinations outside the metropolitan areas that receive so many international tourists that they have to adapt actively. In this paper, Miyajima island in Hiroshima Prefecture, registered as world heritage site, will be taken as an example how tourist destinations in Japan adapt to foreign tourism.

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