Ecophysiological constraints on spore establishment in bryophytes

• 1.Many threatened bryophytes are restricted to patchy and temporary substrates suchas dead wood and tree stems. Their persistence depends on successful colonizations ofnew patches. Spore germination may then be limited by substrate quality and wetness.2.In vitroexperiments were used to test the effects of pH and moisture on the establishmentof spores of the moss speciesNeckera pennataHedw. andBuxbaumia viridis(DC) Moug. & Nestl.3.Low pH and water potential prolonged the lag phase preceding germination andreduced final germination. The interaction between pH and moisture suggests that highwater availability facilitates germination at suboptimal pH, andvice versa.4.The results reflect the species’ habitats: the wood-inhabitingB. viridishad higher capacityto germinate at low pH, while spores of the epiphyteN. pennatashowed earlier germinationat low water potential and survived longer in a dry state. This supports the notionthat bryophytes are most strongly affected by substrate quality during establishment.5.We suggest that a trade-off exists among moss spores between the ability to colonizesubstrates with low moisture-holding capacity and low pH, and that the positive effectof high pH is largely that it speeds up germination thereby enabling the spores toexploit short, moist periods.

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)