Germination and establishment of forest sedges (Carex, Cyperaceae): tests for home-site advantage and effects of leaf litter.

We investigated aspects of germination and seedling establishment that might influence the distribution and diversity of Carex species growing in the forest understory. We tested the ability of Carex communis and C. platyphylla to germinate and establish at plots where adult individuals of one of these two species, or one of two other Carex species (C. backii and C. plantaginea), occurred in an old-growth forest in southern Québec, Canada. We also tested for effects of leaf litter on germination and establishment of these sedges. From a series of experiments in the field and in a lath house, we found no evidence of home-site advantage with respect to germination or seedling establishment. Leaf litter had a negative effect on germination and establishment. The results emphasize the importance of dispersal and colonization events in determining local diversity and distribution of Carex species in upland forests. High frequency of occurrence of C. communis at our study site may result from relatively wide dispersal provided by ants, and a suite of traits associated with ant dispersal in some understory Carex species.