Habitats of the Llano Estacado Introduction Previous Next Page
Page Sibley Nature Center Presents
Slide 2
Introduction The Llano Estacado has one artificial and seven
natural habitats. Each is described in an interactive educational
presentation called a module. This Introduction is the same for
every module. You only need to read it once, and then you can
access each module separately when you are ready for it. To
navigate within this presentation, click on the arrow buttons in
the lower right-hand corner, or use the arrow keys on your
keyboard: The arrow key takes you forward to the next slide. The
arrow key takes you back to the previous slide. The Home key takes
you all the way back to the first slide.
Slide 3
Introduction You may only have time on your visit to view only
the Introduction and one or two of the Habitat modules, but you can
always return to the Sibley Nature Center to view the other
modules. If you wish to view all of the modules, these
presentations will ultimately be available for viewing on CDs or
password- protected websites at your home or schoolwherever and
whenever you have time.
Slide 4
Introduction It is important to view the Introduction
presentation first, because it gives you a fundamental
understanding of the region and places the specific habitats in
context, but the Introduction can be skipped if you have already
completed it. If you have already read the Introduction, please
click on the Habitat Link below for the habitat you are interested
in viewing and go straight to that module. If you havent read the
Introduction, click on the Next Page arrow button first (or use the
right arrow key ). Habitats of the Llano Estacado 1. Playas and
Playa LakesPlayas and Playa Lakes 2. Prairie BrushlandPrairie
Brushland 3. DrawsDraws 4. Canyons and "The Breaks"Canyons and "The
Breaks" 5. Alkali SoilsAlkali Soils 6. Shallow Gravel SoilsShallow
Gravel Soils 7. Sand DunesSand Dunes 8. Human Developed AreasHuman
Developed Areas Next Page
Slide 5
Introduction to the Llano Estacado The Llano Estacado is
Spanish and literally means the Staked Plain or Plain of Stakes.
But "staked" or stakes for several reasons that have long been the
subject of controversy. The region was named the Llano Estacado by
Spanish explorer Francisco Vasquez de Coronado in 1541, when he
crossed what is now the Texas panhandle. The name still holds
today, but why he named it this is not clear.
Slide 6
Introduction to the Llano Estacado The most common explanation
is that the original Spanish explorers would drive stakes into the
ground to mark their trail to find their way back, a common
practice when exploring an unknown flat, featureless landscape,
which certainly describes the Llano Estacado. A second idea has it
that Coronados men had to tether their horses at night using
stakes, because if they wandered off they couldnt be tracked on the
soft, short grass. A third suggestion is that the abundant yucca
stalks make it appear that the land is staked.
Slide 7
Introduction to the Llano Estacado Yet another hypothesis is
that the original word was Estacando, not Estacado. This word means
stagnant, pond, or many ponds, and if this hypothesis is correct,
would refer to the many thousands of playa lakes that are a
prominent feature of the Llano Estacado. Coronado was the first
European to see a playa, which means beach in Spanish, because many
of them had sandy shores. The small ponds eventually dry up and
become stagnant mud pits before turning into typical dry playas. A
simple misspelling may explain it all. Coronado intended to name
the region the Llano Estacando, the Plain of Many Ponds, but
somehow the n got left out of the name by mistake, leaving it
spelled Estacado! Unfortunately, no one knows precisely which of
these explanations for the origin of the name Llano Estacado is
correct.
Slide 8
Introduction to the Llano Estacado Where is the Llano Estacado?
The map shows that most of the Llano is in West Texas, but about
1/3 is in eastern New Mexico. Notice the location of the major
cities on the Llano Estacado are all in Texas. From north to south:
Amarillo, Lubbock, and Midland.
Slide 9
Introduction to the Llano Estacado Where is the Llano Estacado?
Here is a better, more detailed map of the Llano Estacado. The
cities of Amarillo, Lubbock, and Midland are printed in red. This
map is available in PhotoShop format with a file size of 77.3 MB,
so it can be greatly enlarged and still show fine detail. A framed
3x4 print of this map can be found hanging on the wall of the
Sibley Nature Center, available for viewing. If you click on the
map at left, a large version will open up. Try it! (Click the Back
button in your web browser to return here.)
Slide 10
Introduction to the Llano Estacado A physiographic name for the
Llano Estacado is the Southern High Plains Region of the Great
Plains of the United States. The Southern High Plains on the
physiographic map at right is the ivory- colored region below the
Canadian River and above the Pecos River. A physiographic map of a
region shows its physical geography, based on such things as
elevation, soil type, bedrock, and geology.
Slide 11
Introduction to the Llano Estacado The Great Plains is an
enormous part of the United States, consisting of the entire
central part of the country east of the Rocky Mountains and west of
the tall- grass prairie states, extending north from the Mexican
border well into Canada. This region is colored in orange on the
map. Sometimes the Great Plains is termed the Shortgrass Prairie
region, because it is a prairie grassland. It has shorter grasses
than the tallgrass prairie to the east because it is drier.
Slide 12
Introduction to the Llano Estacado The High Plains is
approximately the same as the Southern Great Plains, a large area
consisting of western Nebraska and Kansas, eastern Colorado, the
panhandles of Oklahoma and Texas, and the Southern High Plains of
West Texas and eastern New Mexico. The Southern High Plains is
essentially the same region as the Llano Estacado, approximately
the southernmost quarter of the Great Plains.
Slide 13
Introduction to the Llano Estacado What is the Llano Estacado?
The Llano Estacado is a plateau, a regional landmass consisting of
horizontally-bedded sedimentary rocks or strata that has been
gently uplifted by tectonic forces of the Earth. The uplift was
gentlenot violent as with mountain building, which twists and
breaks the rocksso the sedimentary rocks of a plateau are still
relatively horizontal. The uplift was caused by heat below the
plateau that comes from deep within the Earth.
Slide 14
Introduction to the Llano Estacado The best example of a
plateau in the United States is the giant Colorado Plateau of
southern Utah and Colorado and northern Arizona and New Mexico, the
famous Four Corners Area. The Llano Estacado in many ways is just a
smaller version of the Colorado Plateau, but there are some
important differences.
Slide 15
Introduction to the Llano Estacado Characteristically, millions
of years of weathering and erosion create beautiful and scenic
landforms on plateaus, such as canyons, buttes, mesas, and
pinnacles. Depending on the age and timing and amount of uplift,
these landforms can have high relief (relief is the difference in
elevation between the highest and lowest areas) as in the Colorado
Plateau, seen in the photo at right. The famous East and West
Mitten Buttes in Monument Valley, Arizona. Note the high
relief.
Slide 16
Introduction to the Llano Estacado Landforms can also have low
topographical relief, as is the case with the Llano Estacado. Low
relief means the area is relatively flat (see photo), and this
certainly characterizes the Llano Estacado. Topography refers to
mapping the land in terms of elevation and relief, so a topographic
map shows a regions elevation and relief to one who can read it.
The entire U.S. has been mapped topographically. Rattlesnake
Racetrack, just off Rankin Highway in Midland County, has low
relief.
Slide 17
Introduction to the Llano Estacado Canyons on the Colorado
Plateau are deep with steep canyon walls, such as the Grand Canyon,
but canyons on the Llano Estacado are relatively shallow with
gentle slopes and low bluffs that can simply be termed valleys. The
reason is because the Colorado Plateau has undergone recent uplift,
so erosion now is extremely active, while the Llano Estacados
uplift occurred long ago, so erosion by now has worn down the land
to a condition of low relief. Playa Lake on the Llano Estacado.
Note the shallow depression on otherwise flat topography (low
relief).
Slide 18
Introduction to the Llano Estacado High relief in the Llano
Estacado? Yes! The Llano Estacado does have some areas of high
topographic relief. These are found along the edges of the plateau,
where the land drops precipitously from the top of the plateau to
the valley below. These steep edges or cliffs are called
escarpments. The eastern edge in Texas is the Caprock Escarpment,
and the western edge in New Mexico is the Mescalero
Escarpment.
Slide 19
Introduction to the Llano Estacado High relief in the Llano
Estacado? The Caprock Escarpment near Amarillo and Canyon, Texas,
is so scenic that a state park was created to protect the area:
Palo Duro Canyon State Park. The small Prairie Dog Town Fork of the
Red River created the huge Palo Duro Canyon by slowly cutting into
the Caprock Escarpment over millions of years. Spectacular
landforms, such as famous Lighthouse Rock at left, can be found in
the park.
Slide 20
Introduction to the Llano Estacado Palo Duro Canyon State Park
The Caprock Escarpment is visible in the photo at right. This wall
of horizontally-layered sedimentary rock is the eastern edge of the
Llano Estacado. The red color indicates that the sediments were
originally deposited in non-marine environments, such as river
channels and alluvial plains, and contain an oxidized form of iron
called hematite (blood-rock), which can be ground to form a red
pigment for artwork.
Slide 21
Introduction to the Llano Estacado The Mescalero Escarpment The
Mescalero Escarpment is visible in the photo at right. This wall of
horizontally-layered sedimentary rock is the western edge of the
Llano Estacado or southern High Plains. Here it drops off into the
Pecos River Valley just south of Tucumcari, New Mexico. Once again,
note the considerable topographic relief between the top of the
plateau and the river valley below.
Slide 22
Introduction to the Llano Estacado Characteristics of the Llano
Estacado The Llano Estacado plateau occupies approximately 37,000
square miles (22 million acres). It is larger than the combined
states of Maryland, Massachusetts, New Jersey, and Rhode Island,
and larger than the single state of South Carolina! The region is
devoid of native trees except for the tiny shin oak and mesquite.
As the Southern High Plains, the Llano is cut off from the Great
Plains to the north by the Canadian River Valley. The Llano slopes
gently to the southeast by 8-10 feet per mile. With no geological
relief, the only changes in elevation are the approximately 34,000
shallow depressions called playas. The Llano Estacado is the
largest, isolated non-mountainous geological area in North America,
which is why endemic plants and animals are found here.
Slide 23
Introduction to the Llano Estacado Most students are told that
we live in the Permian Basin, but they do not know what the Permian
Basin really is. Also, isn't a basin a depression rather than an
uplifted area? The Permian Basin is actually a sedimentary rock
sequence, with horizontal (flat-lying) strata (sedimentary rock
layers) found deep underground. Millions of years ago, the Permian
ocean basin was depressed, filled with marine water, and collected
sediment, but now we live on top of the rocks of the Permian Basin,
not in it.
Slide 24
Introduction to the Llano Estacado The Permian Basin The
Permian Basin is actually an informal name that describes a number
of subsurface geologic features: the Midland Basin, the Delaware
Basin, the Central Basin Platform between them, and several
mountain ranges composed of the same strata that have been uplifted
by various events that are scattered around and inside the major
basins. The name Permian Basin was given to this area because it
contains an enormous amount of oil and gas found primarily in
strata of Permian age.
Slide 25
Introduction to the Llano Estacado Most of this Permian strata
(stratified sedimentary rock) is deep underground and isnt visible
anywhere on the surface except in mountain ranges where it has been
uplifted and eroded, such as the Guadalupe Mountains, adjacent to
the Llano Estacado. So we dont really live in a basin or
depression, we live on an uplifted plateau. We dont live in the
Permian Basin, we live on the Llano Estacado!
Slide 26
Introduction to the Llano Estacado The Llano Estacado is a
natural region with its own unique habitats, plants, and animals.
Most of these plants and animals are found in other parts of the
country, but some are endemic, which means they are found only on
the Llano Estacado. Some of these endemic organisms are threatened
or endangered, which means they live in very small populations or
are in danger of extinction of being lost forever.
Slide 27
Introduction to the Llano Estacado Naturalists and scientists
study the habitats, plants, and animals of the Llano Estacado and
other natural regions of the United States. The Llano Estacado is a
relatively small region compared to others, the region is not as
heavily populated as the others, and the region was settled later
than the others. The result is that there is still much to learn
and discover about the habitats and organisms of the Llano
Estacado, and any student who learns about science and history can
do this and make a significant contribution to our area. For
example, a new species of scarab beetle was recently discovered in
the Monahans Sand Dunes State Park by a graduate student. Hundreds
of archaeological sites on the Llano have never been professionally
studied due to lack of resources and investigators.
Slide 28
Introduction to the Llano Estacado Description of the Llano
Estacado The Llano Estacado is an uplifted plateau in a dry region
of the United States, so its habitats are characterized by
elevation, low amount of water, and the consequences of wind and
water erosion. Availability of water is the most important factor.
Most threatened animal species on the Llano Estacado are endangered
because humans have taken so much groundwater that springs have
dried up, not because of over-hunting. Excessive groundwater
removal is an example of habitat destruction, the most common
reason why plants and animals become endangered or extinct.
Slide 29
Introduction to the Llano Estacado Water is necessary for life,
and while the Llano Estacado does get a low amount of rain, it gets
more than deserts, and in some places and times water is abundant.
Even very dry deserts have plants and animals, because some
organisms have evolved adaptations to dry conditions that permit
them to live under such conditions. The Llano has many of these
organisms, but also has many others characteristic of wetter
environments that live in specialized habitats.
Slide 30
Introduction to the Llano Estacado The Llano Estacado is a
semi-arid region that receives more rainfall than arid regions,
such as deserts, but less rainfall than moist or wet regions, such
as forests. A desert receives between 0 and 10 inches of rain a
year, and a forested region receives over 30 inches a year. So, a
semi-arid region usually a grasslandreceives between 10 and 30
inches (25-75 cm) of rain annually. The amount of rainfall is one
of the two primary controls on biomes, ecosystems, and habitats.
The other is temperature, controlled by either latitude or altitude
(elevation).
Slide 31
Introduction to the Llano Estacado Temperature and rainfall
amount (mean annual temperature and precipitation) have been
carefully measured by scientists and are used to describe
ecological zones and regions. The chart abovea
climographillustrates this concept.
Slide 32
Introduction to the Llano Estacado Water is also the primary
agent responsible for erosion and the creation of landforms. This
is true even of deserts, a fact that most people dont realize. All
of the canyons, gorges, buttes, mesas, pinnacles, and columns of
desert regions are the result of water erosion, not wind erosion,
acting slowly over time. The photos at right show the effects of
water erosion in a semi-arid region. Palo Duro Canyon State Park,
Texas
Slide 33
Introduction to the Llano Estacado Sand dunes are the main
consequence of wind erosion, and they usually occur in small areas
in both the Llano Estacado and the United States as a whole. The
deserts of the United States do not have the great expanses of
abundant sand dunes as do the famous deserts of Africa, Asia, and
the Arabian Peninsula. Ours are much smaller. The Llano Estacado
has several small areas of sand dunes, such as the Monahans Sand
Dunes on the southern edge. Monahans Sand Dunes State Park,
Texas
Slide 34
Introduction to the Llano Estacado Water is abundant in the
Llano Estacada only in aquifers, streams, springs, and playa lakes,
not in rainfall. In the case of the playas, the water is ephemeral,
that is, the water is not permanent but rather seasonal or even
episodic, lasting only for a few weeks or months. Despite the
temporary nature of this water, it is nevertheless very important
for the plants and animals of the region and their habitats. Birds
use this water during their migrations, for example. Playa Lakes,
Llano Estacado
Slide 35
Introduction to the Llano Estacado Most of the habitats and
organisms of the Llano depend on the presence of water during some
time of the year. Aquifers are fresh water-bearing rocks in the
shallow subsurface. In this case, the water is not ephemeral, but
constant. However, it is recharged by rainfall at slow rates, and
is thus subject to being extracted too quickly for replacement.
Springs are fed by aquifers, and the springs dry up when the
aquifers become depleted due to drought and human over-use. This is
the case on the Llano Estacado.
Slide 36
Introduction to the Llano Estacado Development of irrigation
technology during the 1940s enabled the exploitation of the
Ogallala Aquifer, now being depleted at unsustainable rates. Since
World War II, the Llano Estacado has experienced expanded
cultivation, making the Llano one of the most
agriculturally-impacted regions in the Western Hemisphere. North of
the Canadian River near Amarillo, the Ogallala Aquifer is recharged
in the foothills of the Rocky Mountains. But only rain that
actually falls on the Llano Estacado recharges the Ogallala Aquifer
here, so it has been depleted much more rapidly. The Ogallala
Aquifer
Slide 37
Introduction to the Llano Estacado Another name for the
Ogallala Aquifer is the High Plains Aquifer. Remarkably, this
enormous aquifer lies beneath the driest grassland in the United
States, allowing it to be used for agriculture irrigation, even
during cycles of drought. This is one of our countrys greatest
natural resources, but few people know about it, and few protect
it. Cotton, wheat, corn, and sorghum are the dominant crops, all
watered using groundwater from the aquifer. Livestock are grazed on
the uncultivated rangelands. The High Plains Aquifer
Slide 38
Introduction to the Llano Estacado The Ogallala or High Plains
Aquifer is the greatest aquifer in the United States. Much of the
water taken from this natural resource was unregulated by either
state or federal agencies. The law in Texas allowed landowners to
extract as much groundwater as they wished, and many took too much.
The result was a depletion of the aquifer, lowering its top (the
water table) hundreds of feet since the 1940s when irrigation
began. Now, this great aquifer is in danger of permanent damage.
Depletion of the Ogallala Aquifer
Slide 39
Introduction to the Llano Estacado The Southern Great Plains
was originally short-grass and mid-grass prairie. Domestic cattle
were introduced to the region in the 1870s by the first ranchers
grazing on endless square miles of grassesand most crops started to
be cultivated during the 1920s. Over- cultivation and over-grazing
of the land replaced the drought-resistant natural plants with crop
plants that required abundant rainfall, making the topsoil
susceptible to wind erosion when the 1930s drought began.
Slide 40
Introduction to the Llano Estacado The massive wind erosion of
the loose topsoil resulted in the Dust Bowl, a period of great
hardship for the farmers that forced many of them to leave the
region and migrate to California in the later 1930s. The Dust Bowl
wind erosion damage was centered in two areas: (1) the Llano
Estacado in Texas and (2) southeastern Colorado and southwestern
Kansas. The land must be constantly protected to prevent further
damage.
Slide 41
Habitats of the Llano Estacado Eight Habitats Let us now
briefly review the seven natural and one human habitat of the Llano
Estacado. An individual 30-60 minute presentation is devoted to
each one, so we will only look at each one on a single slide here.
The eight habitats are listed in the table on the right. Habitats
of the Llano Estacado 1. Playas and Playa Lakes 2. Prairie
Brushland 3. Draws 4. Canyons and "The Breaks" 5. Alkali Soils 6.
Shallow Gravel Soils 7. Sand Dunes 8. Human Developed Areas
Slide 42
Habitats of the Llano Estacado Playas and Playa Lakes Playas
are circular depressions on clay soil that hold water for several
months after a rain. When filled with water, they are called playa
lakes. Playa lakes are important watering places for migrating
birds. They also have interesting and unusual plants and animals
that live only here. There are about 30,000 playas and playa lakes
on the Llano Estacado, providing a unique habitat for many
organisms.
Slide 43
Habitats of the Llano Estacado Prairie Brushland The Prairie
Brushland of the eastern Llano Estacado is a mid-grass prairie
grassland that has experienced an influx and expansion of mesquite
during the last century. This habitat has the traditional mid-grass
prairie plants and animals, but also has abundant mesquite trees
and hummocks that dot the landscape. Prickly Pear cactus is also
very abundant.
Slide 44
Habitats of the Llano Estacado Draws Draws are the valleys of
dry ephemeral streams. Water is abundant in draws only after
infrequent rain storms. During such storms, the stream channel is
typically in flood stage, with great amounts of water moving
rapidly, then later slowly evaporating over several weeks.
Slide 45
Habitats of the Llano Estacado Canyons and The Breaks The
Breaks are the semi-arid canyons that cut into the eastern and
western edges of the Llano Estacado Plateau, the Caprock and
Mescalero Escarpments. Here, water erosion over millions of years
has sculpted the brightly-colored rocks into spectacular landforms,
providing an unlimited number of niches and microhabitats for
organisms.
Slide 46
Habitats of the Llano Estacado Alkali Soils Alkali soils are a
unique feature of Western U.S. landscapes. These are the soils of
arid and semi-arid regions in which high water evaporation has
concentrated carbonate precipitates or salts in the soil, creating
whitish layers termed gyp soils, calcrete, or caliche. Several
specialized plant and animal species are found only in this
habitat. The dry beds of salt playas have alkali soils.
Slide 47
Habitats of the Llano Estacado Shallow Gravel Soils Shallow
gravel soils occur in two areas on the Llano Estacado: (1) the
western edge of short-grass prairie, containing buffalo grass,
pronghorn, and mimosa catclaw, and (2) the southern region of
Chihuahuan desert scrub, containing creosote bush, javelina, and
prickly pear cactus.
Slide 48
Habitats of the Llano Estacado Sand Dunes Sand dunes are a
specialized habitat on the Llano Estacado, with many unique plants
and animals found no where else. The Llano has several sand dune
fields, including the easily- accessible Monahans Sand Dunes State
Park, but also the Blue Sand Hills of the western Llano Estacado
between Lubbock and Amarillo. The Blue Sand Hills are mostly on
private property and have not been well studied.
Slide 49
Habitats of the Llano Estacado Human Developed Areas Humans
have greatly modified the natural landscape where they build towns,
cities, industrial plants, oil and gas fields, windmill farms, and
other structures. Most of these are localized and not harmful to
the environment, but sometimes human areas produce excessive waste
productspollutionthat is harmful to plants and animals. Sometimes
human environments create new habitats that allow new or additional
species to live in the area.
Slide 50
Introduction to the Llano Estacado Habitats of the Llano
Estacado 1. Playas and Playa LakesPlayas and Playa Lakes 2. Prairie
BrushlandPrairie Brushland 3. DrawsDraws 4. Canyons and "The
Breaks"Canyons and "The Breaks" 5. Alkali SoilsAlkali Soils 6.
Shallow Gravel SoilsShallow Gravel Soils 7. Sand DunesSand Dunes 8.
Human Developed AreasHuman Developed Areas You have now reached the
end of the Introduction. Please visit the Habitat of your choice by
clicking on its link below, or return to the beginning of this
Introduction by clicking here.here