Macrolichen substrate selection: Patterns among aspen, non-aspen hardwood, and conifer-dominated forests in the Wasatch Mountains, Utah.
Lichens in montane, forested ecosystems of the Intermountain West and central Rocky Mountains tend to be understudied. Focusing on forested ecosystems in Utah, specifically Santaquin and Payson Canyons, we describe lichen community diversity and composition and their relation to percent aspen cover, and contrast lichens in aspen, non-aspen hardwood and coniferous environments. We collected 351 macrolichens, a total of 34 species and 15 genera, from 22 circular plots with a 34.7 m radius. We found three major gradients in lichen community composition in our study area. First, many species of Xanthomendoza had strong positive correlations with increasing aspen cover, while several Melanohalea species declined with greater aspen cover. Xanthomendoza galericulata was a significant indicator for aspen forests, but this lichen was not limited to aspen as it colonizes various barks flexibly. Second, corticolous and saxicolous taxa positively associated with a trend in lichen species richness, while terricolous lichens associated with the opposite end of this gradient. The third and weakest gradient was related to the cover of non-aspen hardwoods and the presence of fruticose species. Both lichen community composition and species richness differed significantly among aspen, non-aspen hardwood and conifer-dominated forests. In agreement with previous work in other regions, the non-aspen hardwood forests we sampled supported the most diverse and prolific lichen communities. Lichens of our aspen forests are as diverse as those in conifer-dominated forests, which contrasts with some current literature suggesting that aspen woodlands represent hotspots of diversity for many types of flora and fauna. Our finding that aspen-dwelling lichens markedly contrast with lichens on other substrates, including other hardwoods, contributes to our understanding of lichen community composition in arid, montane forests of the central Rocky Mountains.
Holt, E.A., N. Zemp, M. Van Orman, J. Perry, B.T. Williams, and M. Ogden. 2015. Macrolichen substrate selection: Patterns among aspen, non-aspen hardwood, and conifer-dominated forests in the Wasatch Mountains, Utah. The Bryologist 118:357-366.