Photo Essay
Plants and Animals of the Shallow Soil Habitat
On the southern Llano Estacado, and in many places to the south and west of the Llano Estacado, creosote bush flats stretch for miles. People of the region say that the smell of creosote is the smell of rain, for when rain falls, the fresh clean scent fills the air. For most visitors the scenery is horrifyingly the same for miles and miles, horribly bleak, resonating as “the desert.” Members of the 2008 class of the Llano Estacado chapter of the Texas Master Naturalist ventured out on a private ranch during November and spent a day photographing what could be found. The Sibley Nature Center’s executive director later met seven classes of elementary students in Fort Stockton and spent another day investigating the habitat. The two places examined were 60 miles apart, and a few differences were noted (and are indicated in the text below).
Related photo essay: Invertebrates of the Shallow Soil Habitat
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The ranch that the Master Naturalist visited is near the northeastern range limit of the creosote bush. It receives about 13 inches of rain annually, and as a result the spaces between the creosote bushes have some grass cover. At Fort Stockton, with 9 inches of rain, less grass was present.
Large pad prickly pear arrived in the area of the ranch during the cattle drives of the 1930s droughts. The cattle were driven down the dirt roads of the day, and turned into pastures at night, where they were fed prickly pear (after the spines were singed off) that had been trucked from further south. During the 1930s there was no grass at all, and fewer creosote bushes. Creosote bushes have expanded their range since the days of Anglo settlement in the 1880s.
The rancher seeks to control the creosote bushes so more grass will be available for his livestock. It is easy to see where the creosote bushes were sprayed with a herbicide, and where they were not.
Tarbrush (the brown mounds) is often found in association with creosote bush, as is the large leaved Torrey Yucca. In the distance is a large Allthorn bush, another common plant in the habitat. The largest Allthorn in the world is found on the ranch that was visited.
Playas are found on the ranch. Near the edge, some mesquite grows, but you can see small creosote bushes beginning to grow on the slope leading to the playa.
The Master Naturalists spent an hour or more investigating the playa. The tallest man is the rancher, Stan Smith.
Master Naturalist Barbara Driscoll examined a hard packed entrance mound to a prairie dog hole. The calcareous soil of the playa formed the hardest and most compacted mounds any of the group had ever seen.
The prairie dogs had created permanent runways near some of the older mounds, another unusual feature in any prairie dog town.
Fresh runways were also found. Some of the dirt was probably from underground and was spread by the prairie dogs. Since a number of plants with rank, rapid, or succulent growth germinate in disturbed soil, is the creation of the runways a learned behavior to increase food supply?
It was easy to determine which prairie dog holes were active by the presence of their scat (droppings.)
Several prairie dog skulls were located in the prairie dog town. Had a coyote eaten an unlucky one? If one dies underground, its nest mates usually close it up in an unused part of the burrow.
A significant number of other prairie dog bones were also scattered among the burrows.
The prairie dogs were quite wary of the group for the colony was not far from a rural subdivision whose residents sometimes trespass on the ranch just to shoot prairie dogs for fun.
Pronghorn (antelope) often visit playas, especially those with prairie dog colonies, seeking those "disturbed soil" plants. The pronghorn also prefer to be in the open, so they can watch out for coyotes and mountain lions.
Cottontail rabbits are found most commonly near the playas, but jackrabbits are much more common in the creosote bush flats.
Jackrabbit scat was plentiful among the creosote bushes.
Feral hogs have invaded even the creosote bush habitat, thanks to stock tanks supplying a steady source of water.
Coyote scat was plentiful in the habitat.
Chihuahuan Ravens are also common in the habitat.
Roadrunners have their highest population densities in the areas where the large pad prickly pear forms extensive thickets.
This roadrunner was finding some very small prey as he roamed around. He would hunker down, tilt his head, and then with lightening speed, strike at something invisible on the ground, toss his head back and swallow.
In one of the playas, two meadowlarks and a scissortail sought food out in the open.
At the edge of yet another playa, a Harris Hawk waited for a cottontail to blithely hop into the open.
Ladderbacked woodpeckers were found in the mesquites near the playas, and on one the Torrey Yucca seedstalks in the creosote flats.
Cactus wren nests were plentiful - in prickly pear, in allthorn, in lotebush, and in mesquite, but not in creosote bush or tarbrush.
A diamondbacked rattlesnake meandered along the open ground of the habitat.
Roundtailed hornytoads are often found in the habitat, but the Master Naturalists did not find any, while the Fort Stockton students did.
With the first freezes of the fall, some of the varieties of prickly pear turned bright red.
Cane cholla is also found in the habitat, although it is more common further northwest where the shallow gravel soils are dominated by buffalo grass short grass prairies, not creosote bush.
Tasajillo is common in the habitat, as it is in the mesquite brushland habitat, and the southern portions of the canyons and breaks habitat.
Horsecrippler cactus is common in all of the habitats of the region except the bottom of the playas, sanddunes, and in the pocket forests of the draw habitat.
Corypantha cactus dotted the landscape.
Something had knocked some of the green fruit of the corypantha cactus on to the ground.
Creosote bush will bloom with even a half inch of rain.
Tarbrush blooms in the fall.
Tarbrush is a member of the daisy families, but it does not have ray flowers (petals - for the non-botanicaly minded.
October rains in 2008 had stimulated a mass germination of tarbrush seedlings. Most will not survive.
Yucca Torreyi is the tallest and bulkiest plant in the creosote bush flats.
Allthorn has no leaves, but does produce berries for the birds and rodents.
Saltbush is often found in the habitat. The yellowish cluster of seeds are striking in the fall.
Mormon tea, or popotillo, or Ephedra also grows in the habitat, as it does in all but the playa and sanddune habitats. For the plant to have swollen flower buds in November was unusual.
Wolfberry is plentiful in the habitat, as it is in all habitats but the playas. It is drought decidious, so it can put on leaves two or three times a year, depending on rainfall.
Feather dalea only grows in the rockiest soils of the habitat, and is much more common in the canyon and breaks habitat.
Lote is another common shrub of the region, common in all of the habitats except for the playas and sanddunes.
Javelina bush also prefers rockier soils, so it is more common in the canyon and breaks habitat.
Carlowrightia (it has no common name) is a rare plant usually found in soils with a clay content. Previously to being found on Mr. Smith's ranch, it had only been found in the mesquite brushland habitat, where it is very rare.
Tiquilia is a ground cover plant that is common in all but the sanddune habitat. The blooms are about as large as this capital C.
Salvia subincisa is another rare plant of the region, and appears to prefer soils with a clay content, for the only other habitat it has been found in is the draw habitat.
The shallow gravel soils habitat can be spectacular in the fall, with broomweed and white sleepy daisy among the prickly pear, cane cholla, and creosote.
Horehound is usually found where a little bit of water can collect, and is more common around stocktanks and in draws, so to find it in a creosote bush flat was surprising.
Dodder (the white-yellow strings) is a parasitic plant common in the habitat. Here it grew on Spiny Yellow Aster and burro grass.
Old Man's beard (Clematis) also prefers clay soils, and is more common in draws.
Buffalo bur blooms yellow, has prickly leaves, and prefers disturbed soils. It often grows to be a mound two feet across, but drought struck this specimen.
In the bottom of playas, Ratibida tagetes is a common plant. A large mushroom matured after the October rains.
A number of species of Euphorbia were found - all low growing mats. The white sap of the plants can be dangerous if it is gotten in the eyes.
Innocence is more common in rockier soils, so it is most common in the canyon and breaks habitat.
The large-leaved plant, buffalo gourd is uncommon in the shallow soils habitat, only appearing where soils have collected. Sideoats grama (the grass stem in front of the gourd) also prefers a little extra soil, and the salvia shows the soil is somewhat clay-filled.
Croton pottsii is a common plant in all habitats except the sanddunes. It is also known as doveweed, for doves will often feed on its seeds exclusively when the seed is plentiful.
Croton diocus is also common in all habitats except the dunes.
Calylophus, or sundrops, prefers rocky or clay soils.
Brown flowered ground cherry also prefers tight soils. The center of its blossom is dark, hence the "common" name.
Allionia is common in all habitats.
Portulaca is, as well.
Tumbleweed prefers disturbed soils, or soil that are bare from drought.
Syrian rue came to the United States as a dye plant in the 1920s (to Deming New Mexico.) Since then it has spread in every direction, much to the dismay of ranchers, since the plant is toxic to livestock.
Purple ground cherry is confined to the shallow soils habitat, only appearing along roadsides in the roadbed material in the rest of the southern part of the region. It makes a great ground cover in home landscapes.
Hog potato prefers tight soils, but it can be found in all habitats except the sanddunes. It, too, often is a plant that grows at the edge of pavement in roadbed material. Swellings on the root are edible, tasting like Chinese water chestnuts.
The hog potato blooms are striking in close up. Small beans follow the blooms.
Three species of mallow are found in the habitat. Although their blooms are the same color, their leaves are different. This species has crenulated leaves without deep dissection.
This mallow has narrow leaves.
This mallow has deeply palmately dissected leaves, and is the species found in all habitats except the sand dunes. The other species prefer the shallow soil habitat.
The Master Naturalists found the first specimens of Wright's buckwheat on the Llano Estacado. It is more common further to the south, usually in gravelly soils.
The closeup of the buckwheat reveal its bloom structure.
Two species of closely related plants known as dogweed are found in the habitat. This one, a Dyssodia, is an annual.
Annual broomweed is plentiful with summer and fall rains. It prefers bare soil for germination.
The other dogweed is perennial, and is a member of the Pectis genus.
Four nerved daisy prefers gravelly soil, and is often found with innocence.
Perennial broomweed grows in all habitats of the region. It causes bloat in cattle.
Groundsel is also found in all habitats of the region. It causes nitrate poisoning in cattle. Both it and broomweed are grazed when they are the only thing green during drought periods.
Blackfoot daisy is most common in the shallow gravel soil habitat, and in somewhat compacted sand dune habitat, and is more rare in the other habitats. It is a popular xeriscape garden plant.
Prairie zinnia prefers tighter soils, but can be found in all but the sand dune habitat.
Cowpen daisy often grows 3-4 feet tall. Its leaves have a rank odor, but the blossoms are beautiful.
Normally verbena blooms in late winter and early spring, but the Master Naturalists found several such "spring" plants in the fall.
A few of the filaree had tiny purple blossoms, but most of them had red leaves from the effect of frost and drought. It normally blooms from February to April. It is a European plant that came with the churro sheep of the early Spanish settlers to New Mexico, but spread all over the American southwest, as well as Mexico. It may have originally native to northern Africa, and brought to Spain by the Moors when they invaded.
Germander is another spring plant, normally blooming in April. The group also heard Cassin's Sparrows singing - something that also occurs from February to May, when the species nests in the habitat.
Burrograss is common in the shallow soil habitat. The red devil's bouquet is found in all but the sand dune habitat.
Ear muhly is another grass mostly found in the shallow soil habitat.
The seedheads of ear muhly are spread apart, while the burro grass seedheads stay more appressed.
Bush muhly will grow in most habitats, but always underneath a shrub.
Sideoats grama is an ice-cream grass that livestock and other grazers love to eat. A rancher is doing a good job of managing his grazing if it is present on his property.
The Sibley staff is unsure of the name of this species of grass. We found it in the shallow soil habitat in several places in the fall of 2008, after the good October rains. We believe it is an annual, but have not explored the habitat in rainy times to have often seen it.
Tobosa grass is another common species of grass of the habitat. It provides poor grazing, as it is usually only green for a week or two after the rains, and then returns to a wiry rough grass that grazing animals usually avoid.
Bristlegrass is a common grass in every habitat. It is the preferred native grass for birds to eat the seeds.
Black grama is a common species of grass throughout the region.
Sand lovegrass is also common in a number of the habitats, in pockets of looser soil.
Sand dropseed is another widespread grass species.
Windmill grass is also widespread in the region.