Cryptobiotic Soil Crusts

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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.

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., http://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., http://www.soilcrust.org/

Utah’s Desert Fox

Kit Fox, click to view larger image, Photo Courtesy and Copyright © 2009 Bryan Kluever, graduate research assistant, Utah State University Department of Wildland Resources
PhD student Bryan Klueve
with an adult kit fox
that was captured
with a box trap.
Kit foxes are weighed,
fitted with a radio collar,
and then released
Courtesy & Copyright © 2010
Bryan Kluever
Graduate Research Assistant
Utah State University
Dept of Wildland Resources

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

The kit fox just might be Utah’s cutest mammal. Weighing in at four to five pounds or so, the kit fox is about a third of the size of the more common red fox.. The kit fox has delicate cat- like features and it has comically large, furry ears. It’s desert-colored coat is tinged with rusty orange finishing in a long black-tipped bushy tail.

The kit fox is the only desert dwelling fox in North America. In Utah, you’ll find it mostly in the western part of the state, where it lives off field mice and jackrabbits as well as insects, birds, amphibians and fish.

The kit fox has evolved a number of adaptations to deal with the desert’s harsh conditions.. First of all those big ears aren’t just for looks. They help the kit fox dissipate body heat through evaporative cooling.

Secondly, kit foxes are nocturnal, avoiding the high temperatures of the daytime hours. During the day they lounge in subterranean dens.

Kit fox legs are relatively short for a fox. That helps them zig-zag through the brush when chasing prey or being chased. And the pads of their paws are furry which gives them better traction in the sandy soil of desert habitats.

Long droughts are common in desert environments and kit foxes have developed ways to deal with them. During a drought, fewer vixens breed and litters become smaller. Kit fox families maintain large territories—larger than necessary for normal years. So when a drought hits, and the population of prey species plummets, the foxes have a larger area in which to hunt.

Adult kit fox prior to being
released. Note the black
collar antenna on the right
side of the fox.
Courtesy & Copyright © 2010
Bryan Kluever

Kit foxes get top marks in water conservation. Little goes in and little comes out.. A kit fox can exist for many months without ever drinking water. Instead, the fox can draw water from the food that it eats. And that water is used with great efficiency. Little is lost through metabolic processes such as urination, defecation breathing and panting.

Too see pictures of the diminitive kit fox, go to www.wildaboututah.org

Thanks to Brian Kleuwer and Mary-Ann Muffoletto of Utah State University’s College of Natural Resources for supporting this Wild about Utah topic.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.
Credits:
Images: Courtesy & Copyright Bryan Kluever, USU Department of Wildland Resources
Text:     Mary-Ann Muffoletto, Utah State University College of Natural Resources

Additional Reading:

White, P. J. and K. Ralls. 1993. Reproduction and spacing patterns of kit foxes relative to changing prey availability. Journal of Wildlife Management 57:861–867 The Wildlife Society, http://si-pddr.si.edu/dspace/bitstream/10088/510/1/White1993.pdf

Kit Fox (Vulpes macrotis), Wildlife Notebook Series No. 9, Utah Division of Wildlife Resourceswildlife.utah.gov/publications/pdf/2010_kit_fox.pdf

Kit Fox (Vulpes macrotis), Species Fact Sheets, Utah Conservation Data Center, Utah Division of Wildlife Resources, http://dwrcdc.nr.utah.gov/rsgis2/Search/Display.asp?FlNm=vulpvelo

Sagebrush

Sagebrush near Raft River, UT
Sagebrush near Raft River, UT – Photo Courtesy and Copyright 2007 Dr. Leila Shultz

Hi, I’m Holly Strand of Stokes Nature Center in beautiful Logan Canyon.

I was always prone to homesickness when I spent long periods in the Eastern US and abroad. Returning to Colorado for visits, I would break off a small branch of sagebrush to pack in my suitcase. That way I could always take some essence of home along with me. Now I don’t need to do that. The desert air and cold winters here in Utah make it a sagebrush heaven.

The scent that has become so dear to me comes from the volatile oils of the sagebrush plant. Ironically, the smell that appeals so much to me repels most animals. The aromatic properties of the sagebrush are a by-product of chemicals that evolved as a pest deterrent and as anti-freeze. Sagebrush oils have a very bitter taste. Browsers, such as deer and elk avoid the plants, nibbling on sagebrush only in winter months when the concentration of oils has decreased. And even then, only as a last resort. The pronghorn– a North American native that co-evolved with sagebrush–can tolerate it better than other herbivores.

Within the sunflower family, sagebrush belongs to the genus Artemisia – a group of wind-pollinated plants spread mostly across the northern hemisphere. The 400 or so species in this genus include a variety of sagebrushes, sageworts, and wormwoods.

The Atlas of Vascular Plants of Utah lists 19 different species in the Artemisia genus. Among the most common, you’ll find sand sagebrush in the dunes and deep sand regions in southern Utah. Black sagebrush is found on gentle, rocky slopes and windswept ridges in dry, shallow soils, in the foothills and desert mountain ranges. Bud sagebrush is common in salt-desert shrub communities from 4-6000 ft. Almost everywhere, however, big sagebrush dominates. It occurs in valleys, basins, and mountain slopes, at elevations between 2,500 and 10,000 feet. In Utah, you’ll also hear big sagebrush called Great Basin, Wyoming or mountain sagebrush.

Humans have put the unique qualities of sagebrush and its relatives to good use. The volatile oils are toxic to many intestinal parasites, therefore early Americans used it to rid themselves of worms. Oils have also been used to combat infections and to treat internal wounds. Eurasian wormwood–an introduced plant in Utah–is the defining ingredient, in the liquor absinthe, and is used for flavoring in other spirits and wines, including bitters and vermouth. The spice tarragon comes from dragonswort, an Artemisa species found in both Eurasia and N. America.

Ecologists used to think that the presence of sagebrush discourages or suppresses other forms of life. Certainly, sagebrush desert steppes are generally poor in species. The truth is that few species can tolerate the temperature extremes, soil conditions and lack of water the way that sagebrush can. So the next time you see some, pick a leaf, crush it, smell it, and admire this tough but well-adapted Utah native.

Dr. Leila Shultz, a Utah State University expert on sagebrush provided the science information for this piece.

Thanks to the Rocky Mountain Power Foundation for supporting research and development of Wild About Utah topics.
For Wild About Utah and Stokes Nature Center I’m Holly Strand.

 

Credits:

Photo Courtesy & Copyright 2007 Dr. Leila Shultz

Text: Stokes Nature Center: Holly Strand

Sources & Additional Reading:

Digital Atlas of the Vascular Plants of Utah, http://earth.gis.usu.edu/plants/index.html