Studies on the Recovering Capability of Natural Ecosystem at Factory Sites in the Urban Area

Abstract

In order to understand the recovering capability of the ecosystem in the large cities, the dynamics of vegetations, invertebrates and vertebrates were investigated on the openspace about thirteen hectares in Arakawa Ward, Tokyo Prefecture from 1986 to 1990. On this openspace, there were factories from 1917 to 1980. They were removed during the two years ending January 1979.
On the investigated site, vegetations estabulished naturally. In 1988, they consisted from hygrophytic communities with Typha angustifolia, Phragmites communis, etc., and xerophytic communities with herb species such as Solidago altissima, Artemisia princeps, Plantago asiatica, and others.
In respect of the wildlife and insect, 63 species of birds, 4 species of amphibians, 7 species of fishes, one species of crustacean, 30 species of dragonflies (Odonata), 26 species of butterflies and moths (Lepidoptera), and other 76 species of insects were identified from 1986 to 1990.
On this site, the ecosystem which had birds for example Egretta garzetta, Falco tinnunculus interstinctus etc. as high predators, developed.
It was suggestted that the rivers and openspaces from nature habitats to one's destination were important as movement corridors.