都市近郊に既存する樹林地の現状と更新―千葉県白井市の事例―

Abstract

In this report, we investigated the wood species of the woodland which is located in the suburbs of Shiroi city, Chiba prefecture, in order to understand the species composition of the woodland, and estimate the renewal of the forest in the future. The correlation between species and areas was positive and had significant differences in all investigation sections, and the correlation coefficient of deciduous trees was higher than that of evergreen trees. Comparing to the appearance rate of wood species in the sub tree - tree layer, shrub layer, both layers (the same species which were found in both layers of each investigation section), in deciduous trees, Carpinus tschonoskii, Quercus serrata, Quercus acutissima were the highest at the sub tree - tree layer, and Magnolia kobus, Celtis sinensis, Aphananthe aspera, Zelkova serrata were the highest at the shrub layer. In evergreen trees, Quercus myrsinaefolia was high at the sub tree - tree layer, shrub layer and common species, Neolitsea sericea, Ligustrum lucidum were the remarkably high at the shrub layer. We guessed that evergreen trees at the shrub layer grow and the forest floor becomes covered, so the composition will be changed if the abandonment of the woodland is allowed to advance in the future. We consider the woodland where the forest floor is regularly managed to be limited, and the woodland where the abandonment period is short, the forest floor was bright has extended comparatively in the extant woodland in Shiroi city.