Together Apart: Evaluating Lichen-Phorophyte Specificity in the Canarian Laurel Forest

Abstract

The effects of host tree identity on epiphyte lichen communities are a controversial issue, as the results obtained in different forest environments studied are not consistent. We investigated the host preferences for lichens in the laurel forest of Macaronesia. For this purpose, we analyzed the lichen communities growing on the four most common trees (Erica canariensis Rivas-Mart., M. Osorio and Wildpret, Morella faya (Aiton) Wilbur, Laurus novoca-nariensis Rivas-Mart., Lousa, Fern. Prieto, E. Días, J.C. Costa and C. Aguiar, and Ilex canariensis Poir. in Lamarck) in the laurel forest of the Canary Islands. The diversity, richness, and lichen composition showed a repetitive and common pattern with the functional traits studied. Although the existence of specificity with respect to the phorophyte species was not demonstrated, there was a clear affinity of the epiphytic lichens to the physico-chemical features of the bark (texture and pH), canopy architecture, foliar characteristics, etc. Our results highlight the importance of the natural diversity of tree species in the laurel forest. Due to the diversity and uniqueness of the lichen species that support each of the phorophytes, this fact should be taken into account in landscape protection and restoration actions, especially in those islands where the forest is highly fragmented.

Lichens as Bioindicators of Global Change Drivers

“…Changes in land use are increasingly leading natural habitats to be replaced by livestock, agriculture, and plantations of exotic species, which has an acute detrimental effect on tree species diversity. González-Montelongo and Pérez-Vargas [9] explored the host preferences for epiphytic lichens in the laurel forest of Macaronesia (i.e., the Canary Islands) by analyzing the lichen communities on the four most prevalent trees in these forests. They found a recurring and consistent pattern in diversity, richness, and lichen composition, aligned with the tree functional traits that were studied.…”