Mark Larese-Casanova, Author at Wild About Utah

May 23, 2013March 1, 2018

Amazing Adaptations of Utah’s Desert Plants

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

Anyone who lives in Utah knows that it’s a dry state. In fact, around three-quarters of our state is considered desert. A desert is often characterized as an area that receives less than ten inches of precipitation each year. But, high levels of evaporation, which are influenced by temperature, wind speed, and solar radiation, also contribute to creating a dry desert ecosystem.

So, how exactly are plants able to survive in Utah’s deserts, which are so dry? It turns out that the plants that grow and flourish in Utah’s deserts have an amazing array of adaptations for survival.

Many shrubs and trees, such as desert willow, and certain species of sagebrush and mesquite, have thick taproots that grow deep into the soil to reach groundwater. This helps the plants survive the hot, dry summer. Some mesquite taproots have been found to grow as deep as 200 feet to reach a constant water supply.

Cacti, such as the various types of prickly pear, have almost an opposite adaptation. They produce dense tufts of fibrous roots just below the surface of the soil. This allows cacti to quickly absorb water from brief rainstorms, and then store the water in their thick, succulent leaves.

As temperature increases, desert plants face the danger of excessive water loss from their leaves. A thick, waxy coating on the outside of leaves often helps to retain water. The shiny wax also reflects sunlight to keep the leaves relatively cooler. To further reduce leaf temperature and water loss, some plants, such as brittlebush, grow light-colored dense ‘hairs’ on their leaves and stems. These trichomes not only shade the plant, but also aid in absorbing water from morning dew.

If temperatures get too hot, and drought stress too great, some plants, such as creosote bush and ocotillo, may drop their leaves several times each year to ensure survival. Some of these plants have green chlorophyll in their stems so they can still produce food through photosynthesis when there are no leaves on the plant.

While this is just a sample of an amazing collection of adaptations, it’s clear that desert plants are champions of survival in a harsh ecosystem where water is so scarce.

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

Credits:

Images: Courtesy & Copyright Mark Larese-Casanova
US FWS images.fws.gov
Text: Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.
Additional Reading:

Utah’s Desert Dwellers: Living in a Land of Climate Extremes. Wildlife Review. Utah Division of Wildlife Resources
wildlife.utah.gov/wr/0706desert/0706desert.pdf

Deserts. James MacMahon. The Audubon Society Nature guides. 1985. https://www.amazon.com/Deserts-National-Audubon-Society-Nature/dp/0394731395

Natural History of the Colorado Plateau and Great Basin, Harper, St. Clair, Thorne, and Hess (Eds.), 1994. https://www.amazon.com/Natural-History-Colorado-Plateau-Great/dp/0870815113

The Biology of Deserts, David Ward, Oxford University Press, 2009. https://www.amazon.com/Biology-Deserts-Habitats/dp/0199211477

April 25, 2013June 27, 2016

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.

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/

March 28, 2013July 18, 2022

Oolites

Click to view larger image of the Utah's Oolitic Sand, Photo Courtesy and Copyright Mark Larese-Casanova — Utah’s Oolitic Sand, Photo Courtesy and Copyright Mark Larese-Casanova

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

Imagine if prehistoric brine shrimp were responsible for one of the finest examples of architecture in Salt Lake City today.

Okay, so it may be a bit of a stretch, but let me explain. In a previous episode of Wild About Utah, I discussed the life cycle of brine shrimp and the important role that they play in the Great Salt Lake Ecosystem. Well, as the billions of brine shrimp feed on bacteria in Great Salt Lake, they excrete waste in the form of tiny fecal pellets. These pellets, along with sand grains and other bits of debris, eventually settle to the bottom of Great Salt Lake.

In shallow areas of the lake, where wind and waves routinely mix the water, these small particles gradually accumulate layers of calcium carbonate, forming an oolite (spelled o-o-l-i-t-e). This is very similar to how a pearl, also layers of calcium carbonate around a small particle, is formed within the shell of an oyster or mussel. The main difference, aside from a pearl being much larger, is that oolites are typically oblong, rather than round. The beaches on the west side of Antelope Island are a great place to find oolitic sand, which will look and feel as though you have a handful of tiny pearls.

Click to view larger image of the Utah's Oolitic Sandstone, Photo Courtesy and Copyright Mark Larese-Casanova — Utah’s Oolitic Sandstone
Photo Courtesy & Copyright
Mark Larese-Casanova

Around 50 million years ago, large fresh- and salt-water lakes covered parts of Utah, and in these areas, vast amounts of sediments, including oolites, were deposited. Over time, these oolites were compressed and cemented together into limestone.

A quarry near Ephraim in Sanpete County supplied oolitic limestone for the construction of the Governor’s Mansion in 1902 and the original Salt Lake City Public Library in 1905. The Library building, located at 15 South State Street, eventually housed the Hansen Planetarium and is now home to the O.C. Tanner flagship store. The building underwent an extensive restoration just a couple of years ago, and now serves as a shining example of neoclassical architecture in our capitol city.

The truth is, there are tens of millions of years separating oolitic limestone from our modern-day brine shrimp. So, we can’t exactly say that prehistoric brine shrimp were responsible for the existence of the O.C. Tanner building. But, it’s fun to imagine precious gems from around the world housed in a beautiful building constructed from the ‘pearls’ of Great Salt Lake.

Click to view larger image of the historic OC Tanner building made from oolitic sandstone (This building formerly housed the Salt Lake Library and Hansen Planetarium), Photo Courtesy and Copyright Mark Larese-Casanova — Historic OC Tanner Building
(formerly the Salt Lake Library
and later the Hansen Planetarium)
Photo Courtesy & Copyright
Mark Larese-Casanova

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:

Utah Geological Survey https://geology.utah.gov/utahgeo/rockmineral/collecting/oolitic.htm

Utah Division of Wildlife Resources, Great Salt Lake Ecosystem Program
https://wildlife.utah.gov/gsl/facts/oolitic_sand.php

Salt Lake Brine Shrimp, https://saltlakebrineshrimp.com/harvest/

February 28, 2013March 28, 2018

Why is it Colder at Higher Elevations?

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

If the old saying that “hot air rises” is true, then why is it colder at the top of a mountain? Let’s think about it in terms inflating a bicycle tire. If we were to use a bicycle pump, it would compress the surrounding air to a greater pressure as the tire is inflated. This causes air molecules to collide at a greater rate, releasing energy in the form of heat. As a result, the bicycle pump would feel warmer to the touch.

Alternatively, if a CO2 cartridge is used to inflate the tire, compressed air is released, resulting in a cooling effect as molecules rapidly move farther apart. On a warm day, the CO2 cartridge will feel cold to the touch, even frosty. So, the greater the air pressure, the warmer the temperature.

The air around us doesn’t feel like it weighs much, but it’s obvious that it has some mass whenever a helium balloon is released. The balloon, filled with a gas that is lighter than the air in our atmosphere, floats up into the sky. If we think about the amount of air sitting on top of the ground at Utah’s lowest elevation of 2,178 feet above sea level at Beaver Dam Wash in the southwest corner of the state, and compare it to Utah’s highest elevation of 13,538 feet at King’s Peak, that’s an extra 11,360 feet of air! As a result, air pressure is about one and a half times as much at Beaver Dam Wash as it is at King’s Peak. With that increased pressure at lower elevations comes increased temperatures. In fact, with every thousand feet lower in elevation, average temperatures increase about 3.5 degrees Fahrenheit.

On average, annual temperatures are about 15 degrees Fahrenheit warmer in Salt Lake City than up at the Town of Alta, just ten miles up Little Cottonwood Canyon. Even early pioneers noticed this, and decided to settle along the warmer foothills of the Wasatch Mountains. To this day, most of Utah’s population along the Wasatch Front benefits from longer growing seasons and lower heating bills, while taking advantage of higher, cooler elevations for hiking on a summer day or skiing in winter.

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

Credits:
Images: Courtesy and Copyright Mark Larese-Casanova
Text: Mark Larese-Casanova

Additional Reading:

Altitude.org Air Pressure Calculator. https://www.altitude.org/air_pressure.php

If hot air rises, why is it cold in the mountains? Colorado State University Little Shop of Physics. https://littleshop.physics.colostate.edu/tenthings/ExpansionCooling.pdf

Joule-Thomson Effect. Princeton University. https://www.princeton.edu/~achaney/tmve/wiki100k/docs/Joule%E2%80%93Thomson_effect.html

Utah’s basement — Beaver Dam Wash is state’s lowest elevation. Deseret News. Sept. 3, 2006. https://www.deseretnews.com/article/645197370/Utahs-basement–Beaver-Dam-Wash-is-states-lowest-elevation.html?pg=all

Western Regional Climate Center. https://www.wrcc.dri.edu/