Abstract
Seasonal patterns of stem diameter growth of individuals of woody species were analyzed at Mt. Mikasa, Nara, Japan. The process of the growth was fitted to a simple logistic curve, which was used to estimate growth parameters for each species. Growth patterns were categorized based on life forms of the woody species. Possibly due to the high photosynthetic rates and the short life span of their leaves, deciduous broad-leaved species grew quickly over a short period. Conversely, evergreen conifers grew slowly over a long period, and evergreen broad-leaved species showed growth characteristics that were intermediate between deciduous broad-leaved and evergreen coniferous species. Evergreen coniferous and evergreen broad-leaved species would compensate for their slow photosynthetic rates by having extended growth periods which enable them to keep sufficient growth. Among evergreen coniferous and evergreen broad-leaved species, those species with more northerly distribution started growing earlier in spring; however, no tendency was observed in deciduous broad-leaved species. Since evergreen species retain their leaves throughout a year, they will be able to photosynthesize and grow immediately after environmental conditions become favorable. Among evergreen conifers, species that started growing earlier had longer growth periods. Conversely, in deciduous broad-leaved species, the length of the growth period was influenced by the date of growth cessation. For deciduous species that require considerable resources to produce new spring foliage, maintaining growth until late in the growing season may be necessary to maximize growth. Differences in seasonal growth patterns among woody species may promote coexistence among species in a forest.
