Heterotrophs are organisms that must obtain their nourishment from other organisms. Hetero in Greek means “other” trophe means “nourishment.”

The lichen symbiosis is composed of a fungus (the heterotroph) and an algae and/or cyanobacteria (the autotroph). In the lichen, the autotroph absorbs photons from the sun and stores this energy in the chemical bonds of molecules. In turn the fungus, the heterotroph, takes those molecules and uses the stored solar energy to form more molecules, creating a dizzying array of pigments, chemicals, and proteins.

We’re all like lichens – our right brain comes up with novel ideas inspired by the muses, imagination, the spark. And our left brain works with those ideas, building, transforming. Together, they create.

Who might you find in older forests with clean air and clean water — why the lovely Pseudocyphellaria aurata of course! Photo by Jason Hollinger.
From Geiser & Smith 2021 – “Critical loads of N and S for epiphytic microlichena” NADP Critical Load Seminar.

ILichens are speakers of the stones, speakers of the forests, speakers of the desert soils.

If you’ve always wanted to learn how to read a landscape, lichens are like words on a page – their patterns of diversity can tell you about climate, including nearly invisible microclimates, air quality, habitat connectivity, continuity of habitat at time scales that go upwards of 1,000 years.

Cross section of a lichen – the green is the algae (the autotroph) and the clear/gray/white is the fungus (the heterotroph). Together they make their own little ecosystem, exchanging gases, nutrients, inspiration, and their special talents of being. (Candelaria concolor, photo by Jason Hollinger)

As for me, my lichenological research has been stimulated by the potential of using lichens as biomonitors of climate change, air quality, and habitat condition. My studies have included lichen inventories on the ecotone between the Mojave and Great Basin Desert, as well as investigating how the Western North American alpine flora has changed over the past 60 years.

Alpine Lichens

In the 1950s, lichenologist Henry .A. Imshaug (1925-2010) inventoried lichens at 91 alpine peaks across Western North America. But no one has gone back up to see if those alpine lichens have responded to climate change.

Have alpine species disappeared from some areas – have others shifted ranges into new locations? Can we untangle the impacts of air pollution from climate change? Can lichens be used as effective bioindicators of climate change in alpine regions?

Imshaug’s inventory sties from Imshaug, H. 1957, “Alpine lichens of western United States and adjacent Canada” in The Bryologist.

Answering these questions is our goal. My partner Jason Hollinger and I have re-inventoried 12 of Imshaug’s original alpine sites in the Sierra Nevada Mountains of California and western Nevada, along with two in the Washington Cascades, and one in the Intermountain Region. The project has proven to be bigger than we initially anticipated, so we are taking a more modular approach by focusing our efforts first on the California alpine. The California portion of this project was proudly supported by the California Lichen Society. Check out CALS  here!

If you are looking to learn alpine lichens, Jason and I made a little Illustrated Guide to Alpine Lichens in the High Sierras, most alpine lichens have a circumpolar distribution, so even if you’re not in California, there’s a good chance there’s at least a little overlap with your alpine area.

Collection site at Kearsarge Pass, High Sierras, California, USA
A lovely assemblage of alpine lichens — over a dozen species here, can you point to them all?!

Publications from the project:

Carter, O., B. Kropp, N. Noell, J. Hollinger, G. Baker, A. Tuttle, L. St. Clair and S.D. Leavitt. (2019) “ A preliminary checklist of the lichens in Great Basin National Park, Nevada, USA.” Evansia, 36:2.

N. Noell and J. Hollinger. (2019) “Following in the footsteps of Henry Imshaug: Preliminary notes on California alpine lichens.” Bulletin of the California Lichen Society , 26:1.

Noell, N. and J. Hollinger. (2015) “ Alpine Lichens and Climate Change on Wheeler Peak.” The Midden: The Resource Management Newsletter of Great Basin National Park, 15:1.

Great Basin Lichens

Great Basin Lichens. So colorful, so diverse. Most people think that lichens are only found in rainforests, and indeed many species are limited to wet habitats. But desert lichens – they colorfully thrive..

I thought there would be no landscape that could yoke me like the alpine does. That was before moving to Nevada in 2014 with Jason, to try to fill in a gaping hole in North American lichenology: The Great Basin Desert.

The following year, in an unexpected synchronicity, a forward thinking wildlife ecologist at the Nevada Bureau of Land Management got a grant for a three year studying investigating the lichens on the ecotone of the Great Basin Desert and the Mojave Desert. He needed a lichenologist. He got two.

Our preliminary findings are more than remarkable. They are love. And they continue to unfold. So many species to describe. So little time. And playa lichens, yes, a novel community of halophilic lichens that flourish in the ancient lake beds of salt.

A playa in central Nevada. These ancient lake beds and the mountains that contain them on each side – for an endless repitition of basin and range, basin and range — were formed by a rift system. The land mass beneath the Great Basin lifted up, but the land was not flexible enough to bend, and instead miles long north-south cracks formed along the width of what’s now known as Nevada. And then the plates between the cracks started to tilt a bit, and then a bit more, depending on where the geological weight was, and then rocks started tumbling and the plates tilted more and more, one side getting higher and higher, until the sides of these plates each towered over 5,000 feet or more above the basins, sometime going completely vertical and then tipping over to revolve around again. While the other side plummeted deep below. And the in-between places, the basins, these places filled with alluvium. And then water. And then little crustaceans and a few species plants and, of course, lichens. Playa lichens.
Playa lichens: A novel flora (aka lichen community) that has not been documented elsewhere in the world, and 3 species new to science. Results to be published in 2022.

Publications from this project:

Hollinger, J. and N. Noell. (2020) “ New Reports of Great Basin Desert Lichens in California.” Bulletin of the California Lichen Society, 27:2.

N. Noell and J. Hollinger. (2019)The Lichen Flora of the Caliente Field Office Lincoln County, Nevada.” Report to the Nevada Bureau of Management, 144 pages.