Mycorrhiza, vegetative mobility and responses to disturbance of alpine plants in the northwestern caucasus

The hypothesis of a trade-off between vegetative mobility and mycorrhizal infection has been examined. The rate of root arbuscular-mycorrhizal (AM) infection and the extent of vegetative mobility (clonal with annual mobility more than 2 cm, clonal with annual mobility less than 2 cm, and non-clonal) was determined for 77 species in four alpine grassland communities in the Teberda Nature Reserve, the Northwest Caucasus, Russia. The percentage of AM species was similar (74–77%) in all four communities. The mean rate of AM root infection did not differ significantly between four communities. It was shown that vegetatively mobile species (annual mobility>2 cm) had on average a lower rate of root AM infection than species with low or no vegetative mobility. Our results conform with the mycorrhizal infection-vegetative mobility trade-off hypothesis. Gap-preferring species in a highly disturbed alpine meadow (burrowing activity of small and large mammals) had lower rate of root AM infection than species preferring undisturbed microsites. This pattern was also found within two larger families, viz.Poaceae andAsteraceae.