How do lichens get around?

How do lichens get around

Lichens are a cryptic group of organisms that are in fact a symbiosis between a fungus and an alga (or sometimes a cyanobacterium, or even all three). Although lichens appear quickly when a suitable empty area becomes available, little is known about how they move around.

Recent work on lichens in New Zealand and elsewhere suggests that they may not be able to disperse very far, with some being slow to colonise new areas, even 1km away.

The Brian Mason Scientific and Technical Trust has provided a grant to Lincoln University researchers to gain a better understanding of lichen dispersal. The research focuses on lichens in the genus Usnea, otherwise known as ‘old man’s beard’ lichens.

Most New Zealand species in this group live on trees and reproduce asexually by fragmentation or passive dispersal of microscopic balls of fungal and algal cells. This research project is developing genetic methods to identify individual fungal and algal ‘genetic types’ within lichens so that the relatedness of particular lichens can be determined over a range of spatial scales, from within one individual lichen to among populations of lichens in different forests. If lichens are limited in how far they can travel then even those that are geographically quite close together could be genetically quite different; the further they can move, the less pronounced this difference will be. This will help determine their capacity for dispersal and the mystery of how lichens get around.