Fungal parasites reduce lichen fitness

To elucidate parasitic interactions comprising effects of fungal parasites on lichens, Merinero and Gauslaa ran a growth-chamber experiment to assess the effects of the specialised fungi Plectocarpon lichenum and P. scrobiculatae on the fitness of their lichen hosts Lobaria pulmonaria and L. scrobiculata.

Growth rates of infected and non-infected lichens were compared. Infected lichens grew much less than the non-infected plants, and lichen growth rates decreased with increasing parasite abundance. This study shows for the first time that specialised fungal parasites directly reduce lichen fitness, thereby expanding our understanding of parasitic interactions involving lichens and specialised lichenicolous fungi.

See also:
Plectocarpon lichenum: the parasite that makes itself comfortable when it moves into a lichen
The lichen that changes its reproductive strategy according to the climate