St. George Jeepers Trail Report-March 07, 2017
Cedar Pockets, Arizona to Joshua Tree Scenic Byway
The ride today was offered as an option to the concurrent trip to White Pockets, Arizona. Our trip was approximately 50 miles total. We met at the BLM office in St. George and caravanned to the Cedar Pockets exit off I-15. After airing down our tires the 20 vehicles proceeded up the Cedar Pockets Canyon to our first vista stop.
Continuing on west we passed more striking scenery and entered the range of the Joshua tree.
Looking west into Nevada and the Beaver Dam Wash.
After exiting the canyon and entering Beaver Dam Wash we stopped to examine a sinkhole.
Sinkholes are not uncommon throughout the area. In areas underlain with limestone or gypsum the acidic groundwater can seep through fissures and eventually erode them to the point that subsurface caverns form. The ceiling of the caverns can collapse and a sinkhole is formed.
Departing the sinkhole, we traveled north to the Utah state line and entered the Beaver Dam Wash National Conservation area.
Carol Steck poses at the sign.
Jeepers listen to a presentation summarizing Beaver Dam Wash desert tortoise habitat research project.
Beaver Dam Wash National Conservation Area (NCA)
Beaver Dam Wash National Conservation Area (NCA) is a 63,500-acre United States National Conservation Area located in southwest Utah along the borders with Arizona and Nevada. It is managed by the U.S. Bureau of Land Management as part of the National Landscape Conservation System, and was authorized in the Omnibus Public Land Management Act of 2009.
Wildfires destroyed about 25 percent of the tortoise habitat within the Red Cliffs and Beaver Dam Wash national conservation areas in 2005 and 2006. The result was a sharp drop in tortoise populations — up to 50 percent, according to biologists.
The Mohave desert landscapes are not adapted to large or frequent fires. Historically, wildfire was rare because the desert did not produce enough vegetation to carry a fire between shrubs and species like creosote which are naturally fire-resistant, information from the Bureau of Land Management states. However, that changed with the introduction of invasive annual grasses such as cheat grass and red brome, which, when dry, creates a continuous and highly flammable fuel source and can carry flames between native plants, resulting in more severe fires which can take decades or centuries to recover.
Two 100-acre research plots have been selected, one at Beaver Dam and one in the Red Cliffs Desert Reserve north of St. George. Some 5,000 native plants are planned to go in at each site, each hand-dug by staff members and volunteers. The Nature Conservancy, Utah Division of Wildlife Resources, U.S. Bureau of Land Management, U.S. Fish and Wildlife Service, Washington County, National Fish and Wildlife Foundation and the University of Nevada, Las Vegas are partners in the effort.
Big galleta, brittlebush, white bursage, globemallow, muhlenbergia grass and other grasses were planted; the plants were grown from seeds collected locally or elsewhere in the Mohave desert. Local seeds can survive better because they are adapted for the area. The project will also track the number of plants that survive in each plot, the impact of native plants on non-native plants, different planting methods and the most cost-effective methods. The hope is to establish islands of desirable vegetation that will spread throughout the Conservation Area.
Fish and Wildlife Service contributed $40,000, Watershed Restoration Initiative spent $30,000, Red Cliffs Desert Reserve spent $20,000 and more than $12,000 came from The Nature Conservancy. In addition, the Bureau of Land Management funded American Conservation Experience volunteers.
The BLM spent over a million dollars in the year 2000 buying seeds and spreading it by airplane, however, the survival rate was less than 5 percent. If you don’t rake it into the ground, then the seed is very vulnerable to drying out, blowing away or being eaten by rodents.
Habitat plays a vital role in the ability of desert tortoise populations to be able to take hold and thrive. Desert tortoise can always be found within a stone’s throw of creosote because the climate where creosote is found also tends to be ideal for tortoise as well. In addition, the creosote’s root system stabilizes tortoise dens and provides shade.
Desert tortoise like all kinds of vegetation from grasses and forbs to desert flowers including globe mallow, penstemmon, four o’clock, protein-rich stork’s bill, wooly daisy, cactus flowers and cactus pads, mariposa lily, desert marigold, verbena or ice cream plant and evening primrose.
Females lay eggs from March to June and specialists have observed an increase in activity among tortoise after monsoon rains for the past several years. It seems like when you have really good rains the hatchlings have a better chance of success as far as successfully emerging from their eggs and coming to the surface through the sand.
Even so, only five percent of hatchlings born in the wild make it to adulthood due to a high mortality rate among the species. “They might get hit by a car, taken by people as pets, eaten by coyotes, ravens or road runners, a swarm of ants can take them, or if it’s really dry, from lack of food.” – Sources: St. George News, The Spectrum and BLM.
The Joshua Tree Scenic Byway is 16 miles one way over a maintained dirt and gravel road that is passable by most vehicles. The route is passable year round, but may be difficult following precipitation. The Byway travels through desert terrain populated by the northernmost stand of Joshua trees in the northern reach of the Mojave Desert in Utah. In season there are wildflowers and in the spring and autumn, although rare, desert tortoise can sometimes be spotted.
Below, desert mountain scenery along the Joshua Tree Scenic Byway.
After leaving the research plots we traveled a short distance to a scenic side canyon.
Small recess cave that exhibits evidence of past bat habitation and guano (manure) deposits, age unknown.
Below is a plaque placed on the side canyon wall in 1969.
Looking west out the mouth of the side canyon toward Beaver Dam Wash.
Following is a composition summarizing the range, physiology, taxonomy, uses and conservation status of the Joshua tree.
Yucca brevifolia is a plant species belonging to the genus Yucca. It is tree-like in habit, which is reflected in its common names: Joshua tree, yucca palm, tree yucca, and palm tree yucca.
Native to the arid southwest in the states of California, Arizona, Utah, and Nevada, where it is confined mostly to the Mojave Desert between 1,300 and 5,900 ft elevation. It thrives in the open grasslands of Queen Valley and Lost Horse Valley in Joshua Tree National Park.
A dense Joshua tree forest also exists in Mojave National Preserve, in the Cima Dome, (Cima, California), northeast of Kingman in Mohave County, Arizona, as well as along U.S. 93 between the towns of Wickenburg and Wikieup, and designated as the Joshua Tree Parkway of Arizona.
The name ‘Joshua tree’ was given by a group of Mormon settlers crossing the Mojave Desert in the mid-19th century. The tree’s unique shape reminded them of a Biblical story in which Joshua reaches his hands up to the sky in prayer. Ranchers and miners who were contemporary with the Mormon immigrants used the trunks and branches as fencing and for fuel for ore-processing steam engines. It is also called izote de desierto (Spanish, “desert dagger”). It was first formally described in the botanical literature as Yucca brevifolia by George Engelmann in 1871 as part of the geological exploration of the 100th meridian or Wheeler Survey. Englemann was a German born botanist. Plants taxonomically described by him include Englemann spruce and Engelmann’s prickly pear cactus that ranges into the St. George area.
Growth and development
Joshua trees are fast growers for the desert; new seedlings may grow at an average rate of 3 inches per year in their first ten years, then only about 1.5 in per year. The trunk consists of thousands of small fibers and lacks annual growth rings, making it difficult to determine the tree’s age. This tree has a top-heavy branch system, but also what has been described as a “deep and extensive” root system, with roots reaching up to 36 ft.
If it survives the rigors of the desert, the Joshua tree can live for hundreds of years; some specimens survive a thousand years. The tallest trees reach about 49 ft. New plants can grow from seed, but in some populations, new stems grow from underground rhizomes that spread out around the parent tree.
Flowers appear from February to late April. The semi-fleshy fruit that is produced is green-brown, elliptical, and contains many flat seeds. Joshua trees usually do not branch until after they bloom (though branching may also occur if the growing tip is destroyed by the yucca-boring weevil), and they do not bloom every year. Like most desert plants, their blooming depends on rainfall at the proper time. They also need a winter freeze before they bloom. This periodic seed production in addition to seed predation by insects, rodents and hostile germination environment partially explain why it takes so long for Joshua trees to revegetate an area after fire.
Once they bloom, the trees are pollinated by the yucca moth, which spreads pollen while laying her eggs inside the flower. The moth larvae feed on the seeds of the tree, but enough seeds are left behind to produce more trees. The Joshua tree is also able to actively abort ovaries in which too many eggs have been laid.
Uses and cultivation
Fruit Different forms of the species are cultivated, including smaller plants native from the eastern part of the species range. These smaller plants grow 7-8 feet tall and branch when about 2 feet tall.
Cahuilla Native Americans, who have lived in the southwestern United States for generations, identify this plant as a valuable resource. Their ancestors used the leaves of Y. brevifolia to weave sandals and baskets, in addition to harvesting the seeds and flower buds for meals.
Joshua trees are one of the species predicted to have their range reduced and shifted by climate change. There is concern that they will be eliminated from Joshua Tree National Park, with ecological research suggesting a high probability that their populations will be reduced by 90% of their current range by the end of the 21st century, thus fundamentally transforming the ecosystem of the park. There is also concern about the ability of the species to migrate to favorable climates due to the extinction of the giant Shasta ground sloth (Nothrotheriops shastensis) 13,000 years ago; ground sloth dung has been found to contain Joshua tree leaves, fruits, and seeds, suggesting that the sloths might have been key to the tree’s dispersal at the time.
Traveling northeast with Pine Valley Mountain in the distance.
The social highlight of our Jeep trips-lunch!
After lunch we traveled on north to the intersection of the road to the Bloomington Caves. Time did not permit a side trip to the caves so we drove on down the mountain to Navajo Drive in Bloomington and the end of our trip.
Submitted by Bud Sanders