The rate of vegetative spreading in oak fern (Carpogymnia dryopteris) and may-lily (Maianthemum bifolium) was studied by comparing the size of stands formed by individual plants of these species with those of other species growing on the same sites as well as with the time that had elapsed since the last fire on the sites and the age of the tree stand. The average maximum rates of spreading showed to be of similar magnitude in both species, being 12.6 cm/year in oak fern and 12.3 cm/year in may-lily; these values correspond to a radial growth of 6.3 and 6.1 cm year respectively. The maximum radial growth recorded was about 7 cm/year in both species.
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