Effects of elevation on the lichen community palatability in an alpine ecosystem

Abstract

Lichens are present in almost all terrestrial ecosystems, and in some of them, they are the main primary producers. Most studies focus on vascular plant communities, even studies on ecosystems where lichens represent an important part of the primary production, such as alpine ecosystems. For example, the effect of elevation on primary producer community palatability has been studied numerous times for vascular plants, but not once for the lichen communities. In my study, I assess the effect of elevation on palatability, I determine if the community response is due to intraspecies mechanisms or to species turnover, and I identify which other functional traits could explain the change observed in palatability. I collected samples of 14 lichen species, on five sites along an elevation gradient, from 1120 m a.s.l. to 1600 m a.s.l. The samples were used to perform a feeding bioassay using snails, Cepaea hortensis. I had access to data previously collected at the same sites on other functional traits, and I used these data to determine which functional traits could explain the change observed in palatability. I found that as elevation increased, so did palatability, and the intraspecies variation was strongly connected to the increase in palatability. Four of the five functional traits (nitrogen concentration, phosphorous concentration, water holding capacity and specific thallus areal) explained the effect of elevation on palatability. However, the study revealed no relationship between palatability and decomposability.