Bryophyte community structure in a boreal poor fen: reciprocal transplants

The ability of four boreal bryophytes (Sphagnum angustifolium (C. Jens ex R uss.), Sphagnum fuscum (Schimp.) Klinggr., Sphagnum magellanicum Brid., and Pleurozium schreberi (Brid.) Mitt.) to live in each others' habitats was e xamined in a 1-year reciprocal transplant experiment conducted in a poor fe n peatland in northern Alberta, Canada. Growth in length was determined by measuring increase in shoot length, and growth in dry weight was determined by subtracting final dry weight from initial predicted dry weight. Species tolerance ranges, which approximate to fundamental niches, were determined by the significant differences in growth among the species. Stepwise regre ssion analyses indicated that depth to water was the most important factor for all species except S. fuscum. Pleurozium schreberi exhibited the narrow est potential distribution, indicating that its present distribution is lik ely the result of habitat limitation. Although S. magellanicum and S. angus tifolium exhibited wide potential ecological amplitude, the distributions o f these species are partially limited by habitat. Sphagnum fuscum was able to grow in all habitats, and its distribution is not limited by any of the habitat factors measured.