都市景観域における放棄アカマツ植林の二次遷移とアカマツの一斉枯死による影響

抄録

Eight years of changes in an abandoned and isolated pine-plantation (Pinus densiflora SIEB. et ZUCC.) were studied by using the permanent quadrat method in the urban landscape of Chiba in central Japan. In this study we focused on the dynamic pattern of floristic and structural features of a seral forest under drastic changes, such as the abandonment of the management of the pine-plantation, mass-dieback of the dominant pine trees and urbanization processes. The component species of the forest were grouped into five ecological groups, i.e. Pinus, Carpinus-Prunus, Quercus, Aphananthe, and Neolitsea types. They share the vertical strata in a forest, invade orderly, and exhibit differential population dynamics, i.e. declining, maintaining, and increasing populations in the order. The Aphananthe and Neolitsea types have recruitment of trees. The Aphananthe type is especially interesting because of its special adaptation for disturbed/productive ruderal habitats such as urban forest islands. These five types can be regarded as the representative species of each seral stage in the secondary succession.