Lichen Diversity in Great Basin National Park

This article was originally published in The Midden – Great Basin National Park: Vol. 19, No. 1, Summer 2019.

This lichen, Lecidea andersonii, was previously known only from Antarctica and the High Arctic, but was found during the 2017 BioBlitz in Great Basin National Park.

Photo by Steve Leavitt

by Steve Leavitt, M.L. Bean Life Science Museum & Department of Biology, Brigham Young University and Bradley Kropp, Biology Department, Utah State University

When a lichen that had been known only from Antarctica and the High Arctic, Lecidea andersonii, turned up in collections made in Great Basin National Park during a BioBlitz in 2017, it became clear how little is known about lichen diversity and distributions in the Great Basin.

Lecidea andersonii is just one of the 233 lichens that were recently documented in the first checklist of the lichens of Great Basin National Park. This checklist marks an important landmark in characterizing lichen diversity in the Park.

While finding unusual lichen specimens is not uncommon when examining field collections of these underexplored lifeforms in the lab, the overall lichen diversity in Great Basin National Park is particularly striking. Surveys near Wheeler Peak revealed a 4:1 ratio of lichens to vascular plants; and diverse lichen communities are found throughout the Park’s diverse ecosystems.

Rhizoplaca melanophthalma (green rock posy) is a common lichen found throughout the park.

Photo by Steve Leavitt

Some lichens, such as the elegant sunburst lichen (Rusavskia elegans), green rock posy (Rhizoplaca melanophthalma), and sunken disk lichens (Aspicilia sensu lato species), are commonly found from alpine to sage-steppe habitats in the Park.

In other cases, extreme differences in lichen communities are observed. The alpine lichen communities on Mount Washington (3553 m.a.s.l.) and Wheeler Peak (3982 m.a.s.l.) are noticeably distinct in terms of species composition and diversity, largely due to differences in rock substrates. In fact, the Prospect Mountain Quartzite on Wheeler Peak harbors at least 38 rock-dwelling lichens in comparison to the eight documented lichens occurring on the Pole Canyon Limestone comprising the summit of Mt. Washington.

The majority of the lichens in the Park occur on rock surfaces or live inside rock with only fruiting structures appearing on the rock surfaces, e.g. endolithic lichens. Diversity of these endolithic lichens has been particularly fascinating.

Xanthomendoza montana is one of the most common epiphytic lichens in the Intermountain West.

Photo by Steve Leavitt

In addition to Lecidea andersonii – the putative Arctic and Antarctic endemic – other endolithic lichens that were previously known from Subantarctic regions in Argentina were also collected in Great Basin National Park. Future work will be necessary to fully characterize the range of diversity of endolithic lichens in the Great Basin.

A recently described limestone specialist, Tintick’s cobblestone lichen (Acarospora tintickiana), was found occurring commonly in South Fork of Big Wash. Dozens of other uncommon or unexpected rock-dwelling lichens are now known to occur in the Park. This pattern of diverse, unexpected lichen communities is repeated for soil-dwelling lichens, although to a lesser degree.

There is a somewhat surprising lack of epiphytic (growing on another plant but not parasitic) lichens within the Park as a whole. While a number of these were found on trees in relatively moist riparian zones, for the most part species of Xanthomendoza or Melanohalea are the predominant epiphytes. Fruticose (shrubby) lichens, such as beard lichens (Usnea spp.) and wolf lichen (Letharia spp.) are only rarely encountered. Horse hair lichens (Bryoria spp.) occur in nearby mountain ranges but have yet to be documented in the Park. However, the arid climate of this Park is probably a major factor in suppressing epiphyte development.

Rusavskia eleganta (the elegant sunburst lichen) is found from alpine to low elevations habitats.

Photo by Jason Hollinger

A number of cyanolichens – those whose photosynthetic partners are cyanobacteria rather than green algae – were documented, e.g. Enchylium tenax and Peltigera species. Because of their frequency and ability to fix nitrogen, these lichens are potentially significant contributors to the nitrogen economy of the plant communities in which they occur in the Park. Similarly, aquatic or semi-aquatic lichens, such as Dermatocarpon rivulorum, Staurothele fissa, and Verrucaria hydrela, are an overlooked but important component in their respective communities.

Despite the rich, diverse lichen communities documented for Great Basin National Park, a significant proportion of lichen diversity is surely yet to be discovered. The current lichen checklist for Great Basin National Park provides an important baseline for future studies and will be critical for ongoing and long-term assessments of the ecological health in the Great Basin region of western North America.