Abstract
This study was conducted to clarify the distribution and content of nutrients in plant tissue (foliage, branch, root), forest floor (Ao layer), and litterfall in four pioneer stands, i.e., aspen (Populus sieboldii M.), alder (Alnus maximowiczii C.), poplar (Populus maximowiczii H.), and black locust (Robinia pseudo-acacia L.) stands established on Mt. Showa-Shinzan. The content of N in foliage was higher in black locust and alder than them in aspen and poplar. Among the various tissues, nutrient concentrations were higher in foliage than in branch or root. The concentration of N on the forest floor was the highest in the alder stand. The contens of nutrient on the forest floor was in the order of Ca>N>Na>Mg>K>P. The dry matter of the understory biomass was most abundant in black locust stand, but dry weight of organic material on the forest floor did not show significant difference among the study stands. The production of litter were higher in the alder and black locust stands than in the poplar and aspen stands, and the content of N in litter was high in both alder and black locust which are N-fixing species. These results suggested that these early pioneer species would be well adapted to nutrient-poor sites after volcanic eruptions because the rapid growth and N fixation properties that increased nutrient availability in the forest ecosystem.
