Allelopathic Chemical Interaction of Bryophytes with Vascular Plants

Some bryophyte species often dominate plant communities by forming large monospecific mats. The potential mechanisms for this domination are considered to be disturbing light and moisture availability, creating physical barriers which prevent seeds from reaching the soil by the bryophyte mats, and allelopathy of bryophytes. However, allelopathy of bryophytes for the domination is most controversial. This review provides a short overview of allelopathic chemical interaction of bryophyte with vascular plants. The bryophytes contain a variety of secondary metabolites and some of those compounds are secreted from the bryophytes into the rhizosphere soil and act as allelopathic agents. However, only small number of compounds have been evaluated their allelopathic potential. Of those compounds, momilactones and 3-hydroxy-β-ionone were found to secret into surrounding environments from moss species Hypnum plumaeforme and Rhynchostegium pallidifolium, respectively, at phytotoxic levels and inhibited growth of several vascular plants nearby. Those compounds may work as allelopathic substances which contribute to the formation of the monospecific mats of H. plumaeforme and R. pallidifolium by inhibiting the growth of vascular plants in the local ecosystems. Therefore, allelopathic chemical interaction of the bryophytes with vascular plants may play an important role in the establishment of the monospecific mats.