Habitats of the Llano Estacado
Playas
Photoessay – The Playa Classroom of the Ogallala Commons
The Playa Classroom of the Ogallala Commons is the first playa education center in the world. Director Darryl Birkenfield arranges for two and three day Playa Festivals all over the Llano Estacado with elementary schools, focusing on 4th graders. In June 2010, the new playa classroom was dedicated; read the story here.
Playas are small, rounded, shallow temporary bodies of water with gently sloping sides and clay soil basins. Thousands of playas (96% of all playas in the world) dot the Llano Estacado. Playas are a major source of biological diversity and host a distinctive mixture of plants and animals in every season. They provide wetland habitat for waterfowl, shorebirds, and many other animals in a semiarid environment. Most playas are usually dry, sometimes for several years. Periodic flooding and drying results in a more diverse and productive community of plants and invertebrate animals, providing food and cover for a variety of both resident and migratory wildlife.
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The Playa Education Center is a simple three sided building at the edge of a playa. Notice the water collection tanks, to water the landscape of the facility.
Inside are five educational panels, and benches built in to the walls, so visiting students and teachers can get in the shade on a hot day.
Dr. Darryl Birkenfield spoke to 40 people on the day of the dedication.
This view looks northeast from the Playa Education Center, towards Dr. Birkenfield's house, which is also used as a demonstration house for appropriate (green) construction.
The wonders and drama of a playa are often first unnoticed. A crab spider clung to the stem of an Eleocharis (running sedge), hoping for a passing meal, and eventually was rewarded. It grabbed a damselfly that did not see the spider waiting.
A previous meal was still tied to an Eleocharis stem near the scene of the successful attack. Strands of the spider's dragline can be seen wound about the stems.
It took the crab spider over an hour to complete its meal.
An open patch of mud had dozens of small holes.
Looking closer, a tiny species of fly was crawling over the mud by the hundreds. (Go back to the previous picture and see how many you can count, now that you have seen these two.)
The Eleocharis grew in standing water, and in the muck where the water had receded. Bird feathers littered the Eleocharis.
Bird droppings splotched the muck between the sedges.
A floating cow patty (dung) sported germinating seeds. Notice how the vegetation that had been drowned by the water was now coated with algae and bryophytes. This substrate provides food for the hundreds of thousands of tadpoles that swam among the floating detritus.
When the water recedes, the algae quickly dries from a green to brown, but invertebrates are still hiding in the algae -- notice the holes in the algae, and notice the small worm-like creature on the plant stem stretching across the lower left.
Mayfly larvae were found in the water filled with algae. Notice its three "tails" (actually gills). This is the identifying characteristic of mayfly larvae. As adults, they do not eat, only live for a few hours more.
Water fern is an unusual plant. It floats, dangling its roots into the water. Waterfowl (ducks) will eat it.
In this photo, the diminutive size of the water fern becomes apparent.
Redwinged blackbirds nest in plants that stand in water. A male redwinged did his best to convince a female that this was a good place to nest.
A black necked stilt wing-shivered in the Eleocharis. Was this a female signalling readiness to mate, or a male showing off to a female?
Black necked stilts have brilliant red legs, and if you get close enough, they also have red eyes!
The stilts were nesting. Two eggs were hidden in the Eleocharis on small scrapes of the detritus of the pond.
The female duck was brown, as most female ducks are, so the observer did not know what species it was, as it herded a group of ducklings away and hid with them in a thick patch of standing dead weeds in deeper water.
Only about three acres of the playa was truly open water. The rest of the playa was a mosaic of open water and Eleocharis.
Many dead leaves were floating among the Eleocharis stems. Sometimes a small predatory diving beetle could be seen zipping among the floating leaves.
The Eleocharis has tiny white tufts on top of the stems that are the wind-pollinated "flowers."
The playa is an ever-changing tapestry of color, depending on time of day and vegetation stage.
Near the playa, but away from the Eleocharis zone that delineates the clay soils, other plants grow. Plains coreopsis will sometimes fill a playa after the water recedes, but it also will grow in a band of yellow around the saturated zone. Blueweed (the bluish plant) will also have a yellow daisy flower, and it is also an indicator of clay soils. The yellowish grass is little barley, which is often plentiful in clays soils.
Curly dock forms 3-4 foot tall stalts of reddish seeds. It is an exotic from Europe that has adapted well to playas. Its roots produce tannin, and some people have eaten the seeds like cereal, but they are quite sour.
Frogfruit spreads by stolons(aboveground shoots) across the playa bottom and edge, putting up tiny lavender flowers that butterflies adore. Golden little barley seeds gave a nice contrast to the lavender blossoms.
Spotted evening primrose spreads rhizomatously (underground shoots) It grows in the northern Llano Estacado playas, but not the southern Llano Estacado playas.
The bluish colored stems of western wheatgrass are also found in the playa, near the red spires of the curly dock and the pale tan heads of the little barley. Wheatgrass is slowly expanding its range to the south.
Do you see the frogfruit among the wheatgrass and little barley?
Sometimes the wheatgrass (a perennial) grows in dense stands.
The tiny anthers of the wheatgrass jingle in the wind, spreading pollen.
The wheatgrass will grow right up to the saturated soils where the Eleocharis is found.
The circular leaves of Malva neglecta (another European exotic plant) can be found among the barley, too.
Ragweed (the dissected grayish leaves) is found among the barley, as well.
The little barley dies (because it is an annual), and its litter covers the ground, helping species that will bloom in the fall have the perfect conditions for germination.
Some of the barley litter already had seedling poking up.
Further away from the saturated soil of the playa, the clay had already begun to crack. These cracks will help rainwater trickle down into the soil, the next time it rains.
Tiny butterflies known as blues feed on the frogfruit blossoms, and perch on other plants in the playa.
What utilizes the curly dock? the observer could not find anything this time, but someone will discover its ecological relationships with animals and insects!
European bindweed is a terribly invasive plant, usually found along the highways of the region, but now creeping into the playas. What will be the ecological impact?
Yucca is a native grassland plant. This species of thistle is another European invader whose population continues to grow on the Llano Estacado.
The sunsets and sunrises of the llano Estacado can bespectacular!
The water reflects the sunset.
As night falls, the toads begin to sing.