Essays

Moseying: Exploring the Natural World

Salt Playas can be a diverse habitat – just add water!
February 27, 2008

“What a desolate place!” is what most people would say when plunked down on the alkaline shores of a salt playa. Most salt lakes are dry this winter – even Shafter Lake northwest of Andrews. Few folks visit a salt playa. “Mudders” go to Red Lake (renamed Pleasure Lake) east of Stanton and go roaring across the muck in four-wheelers. Birdwatchers go to salt lakes with water in the winter to watch sandhill cranes come to their night time roosts (the cranes sleep standing up in shallow water so coyotes cannot attack them without splashing loudly.

The 2008 class of the Llano Estacado chapter of the Texas Master Naturalist visited a salt playa with water on Saturday February 23rd. The location was on private property where the Midland Naturalists have had permission to visit for many years. The salt lake filled up in the 1980s and held water for six years. It filled up again in the summer of 2007 and is still holding an amazing amount of water (up to five feet deep in places).

Salt cedar bushes have filled the draw that fills the lake. Salt cedars were brought to the United States as an ornamental tree in the 1850s to California. By 1900 their use as an ornamental had spread to Texas. The Haley Library has a photograph of the train station at Germania (once a small town just east of Midland) with a salt cedar tree in their landscape. Salt cedars did not become common in Midland County until the rainy 1980s when tey began to fill many draws and playas on the southern Llano Estacado.

Salt cedar seeds are tiny. They may travel by wind, but they can also travel in bird feathers, and if a stock pond is built today, a salt cedar will sooner or later germinate in the damp soil at its edge. Their foliage appears to be “cedar” like, but it is not evergreen. In the summer a bush is covered with white and pink blossoms that attract many species of butterflies, bees, flies, and wasps, so lepidopterists often survey the swarming hordes during the peak of the bloom season.

Most birds do not like salt cedar. The seeds are too small to eat. Doves of several species will nest in their thick foliage. Larry Cook developed Dove Acres in the bottom of an old playa filled with salt cedar as a dove hunting preserve. On another private ranch in Midland County a draw filled with salt cedars attracted long-billed thrashers to develop a nesting colony. After 15 years, however, the colony died out. The long-billed thrashers normally nest along the Rio Grande near Laredo, so the Midland Naturalists carefully monitored the colony throughout its existence.

At the location that the Master Naturalists visited, the Midland Naturalists discovered a nesting pair of black-tailed gnatcatchers, another species that belongs further south in Texas. The pair raised at least one young last year, and are present again this winter. The gnatcatchers utilize the edge of the salt cedar thicket, and presumably feed on the insects coming to the blooms of the salt cedar, as well as the neighboring habitat of lotebush, catclaw, and creosote bush.

Before the rainy '80s the approach to the salt playa was an alkali sacaton grass filled valley with a few dense thickets of lotebush. Retired Lee High School baseball coach Ernie Johnson found some new additions to the Midland County plant list as he and I worked on the Midland County herbarium housed at the Sibley Nature Center. One of the plants was “Aparejo Muhly,” a low growing grass more common to the Pecos River valley and two annual species of the genus that includes the shrub saltbush, which is also common in the habitat.

Before the playa filled, the bottom was a beautiful alkali sacaton meadow. When the salt lake was filled during the rainy '80s the landowners stocked it with black bullhead catfish and other fish washed in drown the draw from stock tanks ruptured by the floods of the decade. This attracted many species of unusual birds, including a Black Skimmer from the Texas Gulf Coat and a Bald Eagle that fished there for a day or two. Some of the Midland Naturalists watched a mountain lion come get a drink and hunt along the shore. For several years the rare Snowy Plover nested there. As the lake dried salt cedars began to grow along its shore, but when it filled up again and drowned some of the salt cedars a rookery of Snowy and Cattle Egrets filled with nests for a year.

When it dried completely, much of the lake bottom filled with salt cedars, but over the long drought 1992-2004 a number of the shrubs died. When it refilled with water many of the dead salt cedars floated to the shore. Some of the original alkali sacaton meadow began to fill the lake bottom again. After six months the lake bottom is again “bare.”

When it first filled with water, drowning out the vegetation, a thick mat of algae formed as decay set in. This algae died and has now blown to shore, along with the larger litter of the plants. Lines of “wrack” now adorn the shore, as the water has evaporated and the lake level has lowered. At the peak of the water level a handful of cattails began to grow along the shore, indicating that the water was not “salty.” The water has yet to reach the brackish stage, and will only do so after several more months of evaporation.

A small number of sandhill cranes finally began utilizing the location for its nighttime roost. The muddy shore is lined with their footprints, along with many species of mammals coming for a drink. Among the wrack on the shore are many feathers, bones, and other “animal evidences.” After closely observing the wrack for a few minutes, a person can spot several species of shoreflies and other invertebrates. Aquatic invertebrates are present, too, including daphnia, dragonfly larvae, and brine shrimp. Out in the water several species of ducks float, and along the shore several species of sandpiper (birds that love the shore habitat) can be seen running along, feeding on the invertebrates. Birds from the neighboring pasture constantly come to the shore for a drink of water.

In the first week of March, the staff of the Sibley Nature Center will edit the photographs taken by the 2008 class of the alkali soils habitat and will upload the photoessay to the Alkali Soils page of the Habitats section. Please take a look at what they found!