The Unique Biodiversity of Washington County

The Colorado Plateau Courtesy & Copyright Marshall Topham, Photographer
The Colorado Plateau
Courtesy & Copyright Marshall Topham, Photographer

The Great Basin Courtesy & Copyright Marshall Topham, Photographer The Great Basin
Courtesy & Copyright Marshall Topham, Photographer

Mojave Desert with Joshua Trees Courtesy & Copyright Marshall Topham, Photographer Mojave Desert with Joshua Trees
Courtesy & Copyright Marshall Topham, Photographer

Mojave Desert Courtesy & Copyright Marshall Topham, Photographer Mojave Desert
Courtesy & Copyright Marshall Topham, Photographer

Mojave Desert Tortoises Courtesy & Copyright Marshall Topham, Photographer Mojave Desert Tortoises
Courtesy & Copyright Marshall Topham, Photographer

Mojave Desert Tortoise Courtesy & Copyright Marshall Topham, Photographer Mojave Desert Tortoise
Courtesy & Copyright Marshall Topham, Photographer

Mojave Desert Tortoise in a Burrow Courtesy & Copyright Marshall Topham, Photographer Mojave Desert Tortoise in a Burrow
Courtesy & Copyright Marshall Topham, Photographer

For 44 years I have spent considerable time in the company of the desert creatures that reside outside my home in St. George Utah. That number doesn’t include my frequent visits to this area as a young man growing up in Iron County. Back then I did not appreciate the uniqueness of the environment I was invading. I do now. Washington County is an area of unusual biodiversity. An impressive variety of plants and animals call Utah’s Dixie home. Over 100 species of plants and animals found here don’t exist anywhere else in Utah. This extraordinary biodiversity is the result of several factors working together to create an environment that is uniquely its own. The biologically diverse environment of Washington County can’t be found anywhere else on Earth.

Today on the trail, I pondered the reason for such incredible biodiversity I was experiencing. Three large geophysical features collide and overlap here. The Great Basin Desert invades from the North, and the Mojave Desert from the South. The Colorado Plateau, a semi-desert pushes in from the East. Each of these deserts bring with them their own unique complement of plants and animals, making Washington County a mixing pot of biodiversity. In addition to the merging of these three deserts, the incredible local topography plays a role in the diversity of life here as well. Washington county elevation ranges from 1,800 to 10,365 feet above sea level creating a number of different life zones influenced by elevation change. Erosion has also been a contributing factor by created mesas and canyons that provide additional habitat diversity.

I marvel at this environment as I stand in one place and see around me plants that originated in each of these very different desert environments. This same experience is reflected in the wildlife I encounter as I traverse the trails in the Red Cliffs Desert Reserve. Today I encountered juvenile and adult Chuckwallas, sunning on sandstone outcrops or aggressively dismembering a Desert Marigold plant to feast on its blossoms. Tiger Whiptail Lizards dash back and forth across the trail in front of me, as Side-blotched Lizards casually watch me pass by from the edge of the trail. At one point, I had to alter my path a little to avoid a Desert Horned Lizard lying motionless in the trail. Intentionally watching carefully off trail, I observe the occasional Leopard Lizard in the sand or a Desert Spiney Lizard atop a rock. Today was a good day for Mojave Desert Tortoises, as I observed three along my route. All were foraging not far from the trail. Today was a great day to be in the desert, but I will be back again tomorrow. The desert is an incredible therapist. And the price of therapy is extremely reasonable. Who wouldn’t be wild about that?

I’m Professor Marshall Topham and I’m Wild About Utah.

Credits:

Images Courtesy & Copyright
Featured Audio: Courtesy & © Courtesy & Copyright © Anderson, Howe, Wakeman
Text: Marshall Topham,
Additional Reading: Lyle Bingham, https://bridgerlandaudubon.org/

Additional Reading

Wild About Utah pieces by Marshall Topham https://wildaboututah.org/author/marshall-topham/

Washington County Utah https://www.washco.utah.gov/

Snow Canyon State Park, Utah State Parks, https://stateparks.utah.gov/parks/snow-canyon/

Joshua Tree National Landmark, US Bureau of Land Management, https://www.blm.gov/visit/joshua-tree-national-landmark

Red Cliffs Desert Reserve, Washington County & US Bureau of Land Management, http://www.redcliffsdesertreserve.com/

Amazing Adaptations of Utah’s Desert Plants

Amazing Adaptations of Utah’s Desert Plants: Click to view larger image of Tap roots that grow deep into the soil to reach groundwater, Photo Courtesy and Copyright Mark Larese-Casanova, Photographer
Tap roots grow deep
to seek groundwater
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Amazing Adaptations of Utah’s Desert Plants: Click to view larger image of Winterfat trichomes, the light-colored dense ‘hairs’ on leaves and stems that shade the plant and collect morning dew, Photo Courtesy and Copyright Mark Larese-Casanova, PhotographerWinterfat trichomes
Hair-like trichomes provide shade
and absorb dew
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Amazing Adaptations of Utah’s Desert Plants: Click to view larger image of the waxy coating of the Waxy Creosote Leaves, Photo Courtesy and Copyright Mark Larese-Casanova, PhotographerPrickly Pear Cactus
Fibrous roots quickly absorb water
and store it in wide succulent leaves
Photo Courtesy US FWS
Gary M. Stolz, Photographer

Amazing Adaptations of Utah’s Desert Plants: Click to view larger image of the waxy coating of the Waxy Creosote Leaves, Photo Courtesy and Copyright Mark Larese-Casanova, PhotographerWaxy Creosote Bush
Leaf coating inhibits desication
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

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

 

Amazing Adaptations of Utah’s Desert Plants

Amazing Adaptations of Utah’s Desert Plants: Click to view larger image of Tap roots that grow deep into the soil to reach groundwater, Photo Courtesy and Copyright Mark Larese-Casanova, Photographer
Tap roots grow deep
to seek groundwater
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Winterfat trichomes
Hair-like trichomes provide shade
and absorb dew
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Prickly Pear Cactus
Fibrous roots quickly absorb water
and store it in wide succulent leaves
Photo Courtesy US FWS
Gary M. Stolz, Photographer

Waxy Creosote Bush
Leaf coating inhibits desication
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

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