Cryptobiotic Soil Crusts

Click to view larger image of Cryptobiotic Soil Crust, Photo Courtesy and Copyright Mark Larese-Casanova
Cryptobiotic Soil Crust
Photo Courtesy & Copyright 2009
Mark Larese-Casanova

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

Looking out over a Utah desert, we might see relatively few plants- perhaps some sagebrush, maybe a few junipers or Joshua trees, or even some small wildflowers or cacti. What is less noticeable, though, is the living soil crust that holds this entire landscape together. It’s not just sand, but rather an important and vast partnership between bacteria, lichens, algae, and fungi. These soil crusts are often referred to as ‘cryptobiotic’, which means ‘living in suspended animation’. This is a fitting description, considering that water can be so rare in Utah’s deserts.

Cyanobacteria, which is often called blue-green algae, is the backbone of cryptobiotic soil crust. Vast networks of long, microscopic filaments of cyanobacteria and fungi grow in length when they are wet, and leave behind a casing that literally binds the soil together. So, what might otherwise be loose sand not only is less likely to be washed away by water or blown away by wind, but also is able to hold much more water for plants.

Click to view larger image of Cryptobiotic Soil Crust, Photo Courtesy and Copyright Mark Larese-Casanova
Cryptobiotic Soil Crust
Photo Courtesy & Copyright 2009
Mark Larese-Casanova

Cyanobacteria is also extremely useful to desert landscapes for its ability to take Nitrogen out of the air and make it available to plant roots in the soil. Desert soils typically have relatively low nutrients, so this is especially important to desert plants.

In many Utah deserts, cryptobiotic soil crusts can cover up to 70% of the ground surface. Old soil crust can often look like small mountain ranges with black or white peaks inhabited by lichens or mosses. The little valleys in between the tiny mountains of crust are perfect spots for the seeds of desert plants to grow. Over time, the above ground crust can grow up to ten centimeters, or four inches, thick!

However, cryptobiotic soil crust grows at an alarmingly slow rate of about one millimeter per year. So, any soil crust that is disturbed can take a very long time to recover. Depending on the amount of moisture a desert receives, it can take anywhere between 20 and 250 years for soil crust to grow back.

Next time you’re out in the desert, kneel down and have a close look at the telltale peaks and valleys of cryptobiotic soil crust. If you bring a magnifying glass, you just might be able to see some of the lichens and mosses. Be sure to stay on trail, though, and whatever you do, don’t bust that crust!

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:

Images: Courtesy and copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.
Additional Reading:

US Department of Interior. 2001. Biological Soil Crusts: Ecology and Management. Bureau of Land Management Technical Reference 1730-2., https://www.blm.gov/nstc/library/pdf/CrustManual.pdf
Rosentreter, R., M. Bowker, and J. Belnap. 2007. A Field Guide to Biological Soil Crusts of Western U.S. Drylands. U.S. Government Printing Office, Denver, Colorado., https://www.soilcrust.org/

Algae and Moss

Filamentous algae growing in the Colorado River near Lee’s Ferry. Copyright 2011 Wayne Wurtsbaugh, Photographer
Filamentous algae growing in the Colorado River near Lee’s Ferry
Copyright 2011
Wayne Wurtsbaugh, Photographer

Tortula ruralis is one of the few mosses that are common in the desert. Licensed through Wikimedia, Kristian Peters, PhotographerTortula ruralis
one of the few mosses
that are common in the desert
Courtesy Wikimedia
Licensed under CCA 3.0
Kristian Peters, Photographer


Hi, I’m Holly Strand from Utah State University’s Quinney College of Natural Resources.

Algae and moss are plentiful in and around Utah streams and lakes. But lots of people confuse these two kinds of plants. So let’s sort out what each one is.

First, both moss and algae are ancient plant forms that are commonly found in wet or moist places. As primary producers both algae and moss use sunlight to fix energy, giving off oxygen as a byproduct.

Neither algae nor moss has a vascular system to transport water so vertical growth is not their strong suit. Rarely more than an inch tall, a cushion of moss is really a tight cluster of individual moss plants. Bunching helps support the individual moss structures and helps conserve water. Meanwhile, algae comes in many forms, from microscopic one-celled diatoms to huge colonies of giant floating mats, or long flowing filaments. Algae also comes in many colors, such as green, gold, brown and red.

So where are they found? Moss loves shade. Look for it in the deep shadowy gorges and box canyons of the Colorado and Green Rivers. It also thrives in drainages off cliffs and around springs. Damp meadows, tree bases, bogs, and pond edges make great moss habitat. You will seldom find moss in saline environments. Some moss species live submerged in water but most live on land. With the sun-loving algae, the opposite is true—most live in water but some species will grow on damp soil and on the shaded sides of damp walls and trees.

Moss grows very slowly and lives a long time. So it needs a stable environment in which to grow. In contrast, algae is extremely fast-growing. A generation might last from one to several days. Algae is also extremely sensitivity to chemical, temperature and light conditions. Therefore, the presence, absence or quantity of algal species can be a useful indicator of ecosystem health. For instance, your aquatic system is probably in pretty good shape if a number of different species are flourishing. However, if the water is dominated by one or just a few fast growing species and the water starts to turn color—usually green—the system is seriously out of whack. Called algal blooms, these dramatic explosions of growth are usually the result of excess phosphorus or nitrogen runoff in the water.

During blooms the algal mass produces lots of oxygen during the day, but it consumes more than it makes at night. Further, more dead organic material is produced which eats up more oxygen. The result is a severe oxygen deficit. Resident fish, insects, and plants are deprived of oxygen and end up suffocating.

Go to www.wildaboututah.org for links to information on how to prevent algal blooms.

Thanks to 4th grade classes of Fallon Farokhi and Andrea Bostwick for their interest in moss, algae and water quality. Funded by an environmental education grant from the EPA Region 8, the 4th graders investigated and reported on water quality issues in the Bear River watershed. Also, thanks to Wayne Wurtsbaugh and Chuck Hawkins of Utah State University’s College of Natural Resources for their expertise in writing this piece.

For Wild About Utah, I’m Holly Strand.

Credits:
Image: Algae, Courtesy & Copyright Wayne Wurtsbaugh, Utah State University, Department of Watershed Sciences
Image: Moss, Licensed through the Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) Courtesy Wikimedia, Kristian Peters, Photographer
Text: Holly Strand, Utah State University, Quinney College of Natural Resources

Sources & Additional Reading

US EPA. Harmful Algal Blooms https://www2.epa.gov/nutrientpollution/harmful-algal-blooms

US EPA. The Effects of Nutrient Pollution and Harmful Algal Blooms] https://www2.epa.gov/nutrientpollution/effects

US EPA. What You Can Do to Reduce Nutrient Pollution https://www2.epa.gov/nutrientpollution/what-you-can-do

Barbour, M.T., J. Gerritsen, B.D. Snyder, and J.B. Stribling. 1999. Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and Fish, Second Edition. EPA 841-B-99-002. U.S. Environmental Protection Agency; Office of Water; Washington, D.C. https://water.epa.gov/scitech/monitoring/rsl/bioassessment/

Fisher, S.G. 1995. Stream Ecosystems of the Western United States. In River and Stream Ecosystems of the World, edited by Colbert E. Cushing, Kenneth W. Cummins, G. Wayne Minshall. NY: Elsevier
Flowers, Seville. 1973. Mosses: Utah and the West. Edited by Arthur Holmgren.

Moss, Brian. 2010. Ecology of Freshwaters. A View for the Twenty-First Centruy. Wiley-Blackwell.
Utah Division of Water Quality. Nutrients in Utah’s Waters https://www.nutrients.utah.gov/

Utah Water Research Laboratory. 2002. Understanding Nitrate Pollution in Small and Native American Communities. Water Treatment Technology Program Report No. 53. Washington DC, U.S. Department of the Interior.

Lichens

Click for a larger view of Lichens, Courtesy and copyright 2013 Andrea Liberatore, Photographer
Boulder covered in a
variety of lichen species
Copyright 2013
Andrea Liberatore, Photographer

Click for a larger view of Rosette Lichen, Courtesy and copyright 2013 Andrea Liberatore, PhotographerRosette Lichen
Physcia dubia
Lives in both Antarctica
and the Mojave Desert
Copyright 2013
Andrea Liberatore, Photographer

Click for a larger view of Rim Lichen, Courtesy and copyright 2013 Andrea Liberatore, PhotographerRim Lichen
Lecanora muralis
Has anti-cancer and
anti-microbial properties
Copyright 2013
Andrea Liberatore, Photographer

Click for a larger view of Lichens, Courtesy and copyright 2013 Andrea Liberatore, PhotographerGarovagis Rim Lichen
Leconara garovagii
Used in perfume & sunscreen
Copyright 2013
Andrea Liberatore, Photographer

This spring I visited Red Butte Gardens in Salt Lake City for the first time. My favorite part was a small and very non-descript garden, tucked alongside a walkway and devoted to an organism that isn’t a plant at all, but instead a very under-appreciated genera of life – the lichen.

Lichens are those colorful crusts found growing on rocks and trees, and while sometimes plant-like in appearance, they are not plants. Lichens have no leaves, stems, roots, or vascular systems. Even more strange, lichens are not a single organism, but instead a partnership between two organisms: a fungus and an algae or cyanobacteria. Because the fungus is generally the dominant partner, lichens are classified as members of the Fungus kingdom.

The partnership exhibited by these two organisms is an example of mutualism – a relationship where both parties benefit in some way through their interaction. In this case, the fungus provides a safe and secure home for the alga or cyanobacteria, which in return photosynthesizes and provides the fungus with nutrients. Cyanobacteria and algae are typically found in water and are prone to drying when exposed to sun and wind. The fungal partner provides shade and protection from desiccation by sheltering the algae within its body. As a result, lichens are incredibly drought-resistant and can be found in a wide variety of habitats including some of the most extreme environments Earth has to offer. In fact the Rosette Lichen or Physica dubia grows in both Antarctica and the Mojave Desert!

Lichens are not just interesting from a biological perspective, but also a chemical one. Lots of lichens create and exude a suite of chemicals, the roles of which aren’t entirely known. Some are thought make the lichen distasteful to predators, while others may help block harmful UV rays and increase membrane permeability to facilitate the movement of nutrients, water, and cellular byproducts between algae and fungi.

These chemicals have also attracted the attention of scientists, as some exhibit antimicrobial, antiviral, anti-tumor, and insecticidal properties. Many are being analyzed and tested for a variety of medicinal and household uses and may soon become a key ingredient in a physician’s arsenal. Already, these organisms are utilized by humans in a number of different ways, and have been for hundreds of years.

In some native cultures around the globe, lichens are a part of the traditional diet for both people and livestock. However, most lichens have little nutritional value, are bitter tasting, and some can be toxic. Lichen extracts are also used as natural dyes for wool and cloth with colors ranging from browns and purples, to yellows and oranges. Other uses include the manufacture of perfume, cosmetics and sunscreen, a substitute for hops in brewing beer, and as a key ingredient in litmus paper.

Lichens are also sensitive to air pollution, and for that reason don’t typically grow too close to human habitation. In fact, lichens absorb pollutants into their tissues and for that reason can play an important role as an indicator species for pollution problems. As air pollution becomes more widespread, lichen species could be in danger of being lost. And because we have only scratched the surface of what these amazing organisms can do, who knows what future medicine could be lost along with it.

I could go on, as I have only scratched the surface of what these organisms can do. And in the coming years, I think we’ll hear of even more lichen-based breakthroughs in science and medicine. The next time you pass a colorful, lichen-covered rock, take a closer look at these incredible organisms and pause for a moment to wonder about the mysteries, and possible answers, that lie within.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Credits:

Photos: Courtesy & © Andrea Liberatore
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Additional Reading:

Ivins, Robert Fogel (1998) Lichens are Fungi! Utah State University Herbarium. Available online at: https://herbarium.usu.edu/fungi/funfacts/lichens.htm

Center for Ecological Sciences, Indian Institute of Science. Lichen Chemistry. Sahyadri E-news. Issue 34. Formerly available online at: https://wgbis.ces.iisc.ernet.in/biodiversity/sahyadri_enews/newsletter/issue34/lichens_chemistry/lichen_chemistry.pdf See https://www.researchgate.net/publication/257213745_Sahyadri_Shilapushpa_Lichen_Chemistry [Link updated Dec 1, 2023]

US Forest Service (2013) Celebrating Wildflowers: Lichens. Available online at: https://www.fs.fed.us/wildflowers/interesting/lichens/

 

Cryptobiotic Soil Crusts

Click to view larger image of Cryptobiotic Soil Crust, Photo Courtesy and Copyright Mark Larese-Casanova
Cryptobiotic Soil Crust
Photo Courtesy & Copyright 2009
Mark Larese-Casanova

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

Looking out over a Utah desert, we might see relatively few plants- perhaps some sagebrush, maybe a few junipers or Joshua trees, or even some small wildflowers or cacti. What is less noticeable, though, is the living soil crust that holds this entire landscape together. It’s not just sand, but rather an important and vast partnership between bacteria, lichens, algae, and fungi. These soil crusts are often referred to as ‘cryptobiotic’, which means ‘living in suspended animation’. This is a fitting description, considering that water can be so rare in Utah’s deserts.

Cyanobacteria, which is often called blue-green algae, is the backbone of cryptobiotic soil crust. Vast networks of long, microscopic filaments of cyanobacteria and fungi grow in length when they are wet, and leave behind a casing that literally binds the soil together. So, what might otherwise be loose sand not only is less likely to be washed away by water or blown away by wind, but also is able to hold much more water for plants.

Click to view larger image of Cryptobiotic Soil Crust, Photo Courtesy and Copyright Mark Larese-Casanova
Cryptobiotic Soil Crust
Photo Courtesy & Copyright 2009
Mark Larese-Casanova

Cyanobacteria is also extremely useful to desert landscapes for its ability to take Nitrogen out of the air and make it available to plant roots in the soil. Desert soils typically have relatively low nutrients, so this is especially important to desert plants.

In many Utah deserts, cryptobiotic soil crusts can cover up to 70% of the ground surface. Old soil crust can often look like small mountain ranges with black or white peaks inhabited by lichens or mosses. The little valleys in between the tiny mountains of crust are perfect spots for the seeds of desert plants to grow. Over time, the above ground crust can grow up to ten centimeters, or four inches, thick!

However, cryptobiotic soil crust grows at an alarmingly slow rate of about one millimeter per year. So, any soil crust that is disturbed can take a very long time to recover. Depending on the amount of moisture a desert receives, it can take anywhere between 20 and 250 years for soil crust to grow back.

Next time you’re out in the desert, kneel down and have a close look at the telltale peaks and valleys of cryptobiotic soil crust. If you bring a magnifying glass, you just might be able to see some of the lichens and mosses. Be sure to stay on trail, though, and whatever you do, don’t bust that crust!

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:

Images: Courtesy and copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.
Additional Reading:

US Department of Interior. 2001. Biological Soil Crusts: Ecology and Management. Bureau of Land Management Technical Reference 1730-2., https://www.blm.gov/nstc/library/pdf/CrustManual.pdf
Rosentreter, R., M. Bowker, and J. Belnap. 2007. A Field Guide to Biological Soil Crusts of Western U.S. Drylands. U.S. Government Printing Office, Denver, Colorado., https://www.soilcrust.org/