Bryophytes and nutrient cycling

Direct information on nutrient cycling through bryophytes is limited and often incomplete. Evidence bearing on the sources and pathways by which nutrient elements are acquired (e.g. aerial deposition, throughfall and substratum) and lost (e.g. leaching and decomposition) is critically discussed. The need to distinguish between the extracellular and intracellular location of elements is emphasized. The involvement of microorganisms and the problems of accurately measuring decomposition are considered. A summary is given of recent laboratory work on the internal redistribution of elements in Rhytidiadelphus squarrosus and of field experiments involving fertilizer addition to Pseudoscleropodium purum; their significance is assessed.