Productivity of bryophytes in polar regions

The productivity of various South Georgian moss species has been measured and some comparative data from Disko Island, West Greenland, are also considered. Two main aspects of growth have been assessed; crop growth-rate and net annual shoot production, using methods which included the coring of undisturbed stands and the growth of shoots in culture. It was demonstrated that methods must be selected with reference to the species to be studied as differences in growth form affect the suitability of each technique. Considerable variation in productivity was found between sites and some habitat factors were identified which might account for these.