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.