Fig. 1 Study area

Fig. 1 Study area

Table 1 Standards requisite for preserved trees in each ward in Tokyo Metropolis

Fig. 2 Density of preserved trees in 20 reserched wards of Tokyo Metropolis (the 3 wards marked with a star ( ) are those not researched) Fig. 3 Conditions of preserved trees by owner ship and location in 6 researched wards (along east-west belt)

Fig. 4 Density of the top 11 species of preserved Thick line shows ward (ku) boundary.

trees in 20 reserched wards of Tokyo Metropolis Thin line shows 'block' boundary.

Fig. 5 Species diversity concerning preserved trees in the 20 reserched wards of Tokyo Metropolis

Table 2 Constitution of species concerning preserved trees in 20 researched wards of Tokyo Metropolis

1/l=1/ƒ ƒïi2 H L=-ƒ ƒïilogƒïi J=H L/H Lmax

Masai, Y. (1990): Tokyo: From a fedural million city to a global supercity. Geog. Rev., 63B, 1-16. Rowntree, R. A. (1984): Ecology of the urban forestintroduction to part I, Urban Ecology, 8, 1-11.

Distribution an Species Constitution o reserve Trees in the 23-ward Area of Tokyo Metropolis Naoto ISHIZAKI* Many cities in Japan have only a few large public open spaces with woods, but they have many small patches with garden trees scattered in private land. Among various types of garden trees, tall tree is the most momentous amenity resource in urban areas and as an important item in composed townscapes. The aim of this study is to make clear the distribution and species component of preserved tall trees which have been planted in private land in the Ward area (23 wards) of Tokyo Metropolis, Japan's capital city. In this study the author used data on preserved trees in 20 wards (refer to Table 2) as an index for the degree of accumulation of these trees. The result of the data analysis can be summarized as follows: 1. The 12,224 tall trees located in 20 wards can be classified into 122 species. 2. The density (n/km2) of preserved trees is generally high in wards located in upland and low in those located in lowlands (Fig. 2). 3. The main component species, which account for over 1% of all trees, are the following 11 species: Zelkova serrata, Ginkgo biloba, Castanopsis (main species is Castanopsis cupidata), Prunus (main spe cies is Prunus ~yedoensis), Pinus (main species are Pinus densiflora and Pinus thunbergii), Cinnamomum camphora, Quercus (main species is Quercus mysinaefolia), Cedrus deodara, Celtis sinensis, Aphananthe aspera, and Machilus (main species is Machilus thunbergii) (Table 2). Among these, Zelkova serrata, Ginkgo biloba, and Castanopsis occupy over 10% of the all trees, and are generally distributed in all 20 wards (Table 2). 4. Exotic species include 45 species, which correspond to 40% of all 122 recorded species and to 25% of all trees. Seven of these, Zelkova serrata, Castanopsis, Pinus, Quercus, Celtis sinensis, Apha nanthe aspera, and Machilus, are local species. 5. The distribution patterns of these main component species can be divided into two types: widely distributed pattern (Zelkova serrata, Ginkgo biloba, Castanopsis, Cinnamomum camphora, Celtis sinensis, and Aphananthe aspera), and localized pattern (Prunus, Pinus, Quercus, Cedrus deodara, and Machilus) (Fig. 4). Among the former, the distribution patterns of Zelkova serrata, Ginkgo biloba, and Castanopsis are different in each high-density zone: Zelkova serrata is distributed in the outer city zone, especially the western part; Ginkgo biloba in the inner area, and Castanopsis in the central - Geographical Review of Japan 67A-11 803-817 1994 * Graduate Student, Chiba University.

western part of the upland (Yamanote area). The latter type is divided into three patterns: 1) Prunus, Qercus, and Cedrus deodara occupy the upland, 2) Machilus occupy the lowland, 3) Pinus distribution is divided between a part of the upland and into a part of the lowland. 6. From the viewpoint of species diversity of the preserved trees, the 20 studied wards are divided into two zones according to the values calculated by diversity indexes (Fig. 5). Eight wards-suginamiku, Nakano-ku, Toshima-ku, Shinjuku-ku, Shibuya-ku, Meguro-ku, Minato-ku, and Shinagawa-kushow high rates, and they are located on a part of the upland area (bordering the Yamanote area and along the JR Chuo Rail Line). The remaining 12 wards have a low rate, and all of them except Katsushika-ku are divided into two sub-types: Zelkova serrata type and Ginkgo biloba type. The former are located in the outer city zone: Nerima-ku, Setagaya-ku, Itabashi-ku, Kita-ku, Adachi-ku, and Edogawa-ku ; the latter -Bunkyo-ku, Arakawa-ku, Taito-ku, Sumida-ku, and Koto-ku-are in or near the Shitamachi area (Fig. 5, Table 2). Key words: tall tree, preserved tree, townscape, amenity resource