Lichen Diversity in Great Basin National Park

First published in The Midden*, Great Basin National Park's newsletter, Vol. 19, No. 1, Summer 2019. By Steve Leavitt (M.L. Bean Life Science Museum and Department of Biology, Brigham Young University) and Bradley Kropp (Biology Department, Utah State University).*

During a BioBlitz in Great Basin National Park in 2017, collectors found Lecidea andersonii, a lichen previously known only from Antarctica and the High Arctic. The find showed how little is known about which lichens live in the Great Basin, and where.

It is one of 233 lichens in the park's first lichen checklist, a landmark in describing its lichen diversity.

A park rich in lichens

Unusual specimens are common when collections of these little-studied organisms reach the lab, but the park's overall diversity stands out. Surveys near Wheeler Peak found four lichens for every vascular plant, and diverse communities occur throughout the park's ecosystems.

• Everywhere. Some species — the elegant sunburst lichen (Rusavskia elegans), green rock posy (Rhizoplaca melanophthalma) and sunken disk lichens (Aspicilia in the broad sense) — occur from alpine areas down to sage steppe.
• Rock makes the difference. The alpine communities on Mount Washington (3,553 m) and Wheeler Peak (3,982 m) differ sharply, mostly because of the rock. Wheeler Peak's Prospect Mountain Quartzite carries at least 38 rock-dwelling lichens; the Pole Canyon Limestone of Mount Washington's summit, eight.

Lichens in and on rock

Most of the park's lichens grow on rock, or inside it, with only their fruiting structures showing at the surface — endolithic lichens, whose diversity has been especially intriguing.

• Besides Lecidea andersonii, the apparent Arctic and Antarctic endemic, the park yielded endolithic lichens previously known from subantarctic Argentina.
• A recently described limestone specialist, Tintick's cobblestone lichen (Acarospora tintickiana), is common in the South Fork of Big Wash.
• Dozens of other uncommon or unexpected rock lichens are now known from the park. Soil lichens show the same pattern, less strongly.

Few lichens on trees

Epiphytic lichens — growing on plants without being parasites — are surprisingly scarce. Some grow on trees in moist streamside areas, but Xanthomendoza and Melanohalea species dominate. Shrubby (fruticose) lichens such as beard lichens (Usnea) and wolf lichens (Letharia) are rare, and horsehair lichens (Bryoria), found in nearby ranges, have not been recorded in the park. The dry climate is probably a major reason.

Nitrogen fixers and water lichens

• Cyanolichens, whose photosynthetic partner is a cyanobacterium rather than a green alga — such as Enchylium tenax and Peltigera species — were recorded. Common and able to fix nitrogen, they may add significantly to the nitrogen supply of the plant communities they live in.
• Aquatic and semi-aquatic lichens, such as Dermatocarpon rivulorum, Staurothele fissa and Verrucaria hydrela, are overlooked but important parts of their communities.

Much still to find

Much of the park's lichen diversity surely remains undiscovered, and more work is needed on its endolithic lichens in particular. The checklist gives a baseline for future studies and for long-term assessment of ecological health across the Great Basin.

Sources

• National Park Service, Great Basin National Park, "Lichen Diversity in Great Basin National Park," The Midden, Vol. 19, No. 1, Summer 2019. https://www.nps.gov/articles/000/lichen-diversity-in-great-basin-national-park.htm
• The article's photographs, by Steve Leavitt and Jason Hollinger, are not reproduced.
• Words on this page from people and organisations outside the federal government are paraphrased; rewritten in hubnx's own words.