There were few researches in Japan on revegetation techniques for the restoration or reclamation of semi-natural grasslands. Miscanthus sinensis is a major dominant species in the Japanese semi-natural grasslands, which sometimes produces species-rich plant communities. The present study aimed to describe the early stage of growth patterns in M. sinensis and two subordinate species, Aster microcephalusand Potentilla freyniana, taking competitive interaction for light into account. We made a one-year pot experiment observing the growth of the subordinate species surrounded by pots with M. sinensis with and without fertilizer input in a hexagonal design. Results showed that M. sinensis in unfertilized pots failed to establish closed canopy within a single season. M. sinensis in fertilized pots had quarto biomass compared with that in unfertilized M. sinensis. Relative photosynthetic photon flux density at the ground level was 20% after one and a half month onwards after establishment. P. freyniana significantly decreased biomass due to its low statue by the severe shade of M. sinensis compared with those in unfertilized treatment, while A. microcephalus did not decrease the biomass escaping from shade by developing leaves at vertically higher position than that in unfertilized treatment. Possibility for the persistence of subordinate species under the predominance of M. sinensis with or without fertilizer input was further discussed.
