Vegetation Recovery of Quarrying Sites in the Kitaikoma Area, Osaka

The growth of planted Alnus Sieboldiana and Pinus densiflora trees in 15 sample plots in the Kitaikoma area was surveyed for the purpose of studying the process of vegetation recovery in sites greatly disturbed by quarrying of ‘masa-soil, ’ a soil made by the weathering of granite rock. The growth of Alnus trees exceeded that of pine trees in a few years after the 1:1 mixed planting of very young trees, which resulted in the extinction of pine trees from the stand. The number of plant species in the forest floor, including tree species such as Cornus macrophylla, Callicarpa japonica, Neolitsea sericea, etc., increased as the stand age increased. The total nitrogen content in the top soil of Alnus stands has apparently increased with the passing of time, though the content was less than one-tenth of that of a near-by undisturbed Charnecyparis obtusa stand.