The habitat of coastal plants in the Later Jomon in an inner coastal zone of the former Zushi Bayis discussed based on the number of fossil opal phytolith assemblages from the Ikego site in the northeastern part of Miura peninsula, Japan. The average values of the highest number of sixphytolith types (Carex, Leymus, Ischaemum, Imperata, Calamagrostis, Phragmites types) in each microtopographic division (foreshore, bean, dune I, dune II, dune III, marsh I, marsh II, and marsh III) were obtained from the surface sediments in several regions including Onneto, the estuary of the Mukawa River, Rokkasho, the estuary of the Oirase River, Aiofutajima, and the estuary of the Obitsu River. The distribution of source plants and the depositional landform of zonation areas were reconstructed from the relationship between the number of fossil opal phytolith assemblages and its value. It was suggested that a regressional event took place within 150 years from 2, 800 years B. P. at the transgressional stage in the former Zushi Bay.

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This study examined the effects of heat island on the flowering dates of Prunus yedaensis in the wards of Tokyo in 2004. The main results were summarized as follows.
1) The distribution of the flowering dates of P. yedoensis corresponded well with the mean temperatures in March 2004. The flowering dates in the central urban area were earlier than those in the suburbs. This clarifies that heat island influences the flowering dates of P. yedoensis.
2) The relationship between flowering dates and monthly mean temperatures in March was confirmed through the flowering process mechanism using an accumulated temperature model.
3) The authors tried to estimate the monthly mean temperatures in March using the flowering dates. The difference between estimated values and actual values of the monthly mean temperatures in March was less than 0.3°C at most observation points, and the root mean square error was 0.2°C at all observation points.
Therefore the flowering date of Prunus yedoensis is an indicator of local climate such as urban heat island.

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There are several irrigation ponds in the city of Handa and the town of Agui, central areas on the Chita peninsula, Aichi Prefecture. Recently, those irrigation ponds have been decreasing in number. The cause and the manner in which these ponds had been disappearing were clarified by focusing on the spatial variation in the decrease rate based on land uses.
The study methods adopted were as follows: the study area was divided into 500-m grid cells and classified according to their dominated land use. The author also verified in the field all the irrigation ponds that were recorded in the “Irrigation Pond Ledger” (a survey carried out by Aichi Prefecture in 1998) of the study area. Further, the number of irrigation ponds was counted and the ponds that had disappeared in every grid cell were recorded. The disappearance rate of irrigation ponds for every land use category was calculated and these rates were compared.
Most of the irrigation ponds in this area existed on farmland on which land consolidation had not been undertaken or farmland consisting of many scattered artificial constructions. The irrigation ponds in these land use areas had low capacity, small irrigation area and a high disappearance rate. On the other hand, there were few irrigation ponds on residential land and farmland on which land consolidation had been undertaken. The irrigation ponds in these land use areas had relatively high capacity and large irrigation area, and their disappearance rate was low. The following conclusions can be drawn on the basis of these results:
1) In areas where land development had not been undertaken, the value of small-sized irrigation ponds decreased; hence, they were abandoned and they disappeared.
2) During the land development of residential land and new farmland, small irrigation ponds were destroyed. However, large irrigation ponds were left and maintained. On completion of the land development process, most of these large irrigation ponds were utilized for purposes other than the original ones.

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