LOCAL-RATE OF SPREADING AND PATCH DYNAMICS OF AN INVASIVE MOSS SPECIES, ORTHODONTIUM LINEARE

Spatial pattern of invasion of Orthodontium lineare in a coniferous fo rest was studied over six years at two sites using one 10 x 10 m perma nent plot at each site. In this habitat, O. lineare forms discrete col onies. During the observation period the numbers of colonies and their total areas increased considerably. Annual colony mortality ranged fr om 0.5% to 5% of the total area colonized by O. lineare; this proporti on varied greatly between years and substratum types, indicating the v ariability of factors responsible for mortality. The high rate of inva sion results from a considerable capacity of O. lineare to colonize al l the available substratum at each site; its further spread appears to be limited by substratum availability.