Functional traits of epiphytic lichens in response to forest disturbance and as predictors of total richness and diversity

Abstract

Epiphytic lichens are good ecological indicators of climatic and environmental changes. The physiology of lichens is related with their morphology and anatomy (traits) and thus the response to changes in the environment could be related with these traits. In this study we evaluate lichen functional traits to understand the mechanisms of community assembly in response to deforestation of tropical montane forests in Ecuador. Based on this, we propose and indicator value as a complement to evaluate the disturbance level of forests. Finally, we evaluate the use of selected functional traits to infer total species richness and diversity of tropical montane forests. We assessed nine different traits related with photobiont type, growth form, reproductive strategy and chemistry of epiphytic lichens on the trunk bases of 240 trees in three types of forests according to a disturbance gradient (primary forests and secondary vegetation). Most functional traits of the lichen communities were related to structural changes (i.e canopy cover and tree diameter) along the forest disturbance gradient. Several functional groups of lichens as cyanolichens, and those with a gelatinose, filamentose and squamulose growth forms and species without secondary compounds were more abundant in primary forests. On the other hand, fruticose, foliose species with narrow lobes, and with lirellae were most abundant in disturbed forest. Growth forms are useful to infer total lichen richness and diversity in montane tropical forests. Based on these results we recommend the use of lichen functional traits as a tool and a complement for conservation studies and forest management.