Physiographic features

The Limestone Hills ecological site is on hill slopes within LRU 42.8. Elevation ranges from 3500 to 5500 feet. Soil depth can range from very shallow to shallow to limestone and dolomite bedrock. Slopes are greater than 25 percent and are generally between 30 and 60. Aspect is very important to ecological site dynamics.

The Limestone Hills ecological site occurs on slopes of hills, ridges, and mesas and is most closely associated with the Very Shallow Ecological Site, which occurs on summit positions. The Limestone Hills is also closely associated with the Shallow Ecological Site which occurs on lower alluvial fans where a shallow petrocalcic layer has formed. The Limestone Hills site includes, on average, about 15 percent rock outcrop.

Geology: The primary geologic formations that make up the parent material for the Limestone Hills Ecological Site include the Seven Rivers, Tansil, Yates, and to a lesser extent the Capitan Limestone. During Guadalupian time of the Permian Period, dynamic sedimentation of carbonate and evaproite rocks occurred around the rim of the Delaware basin creating an ideal environment for the development of a large coral reef. The rim was topographically high; the waters were shallow, well-ventilated, agitated, and warm. In this excellent marine-life environment the great Capitan Reef began to form. The Capitan Reef grew rapidly and flourished throughout Guadalupian time, surrounding the Delaware basin, controlling environments and influencing sedimentation (Kelley, 1971).

On the landward side of the reef (the backreef) the Seven Rivers, Yates, and Tansil formations developed. The first was the Seven Rivers Formation. The sediments of the Seven Rivers deposited at a time when conditions became drier, and the basin tended toward hypersalinity. The Seven Rivers contain gray to white dolomitic limestone, white to red gypsum, orange-red siltstone, and shale. Within the LRU, the Seven Rivers Formation is considered the surface layer on Azotea Mesa, Seven Rivers Hills, and West Hess Hills. The Seven Rivers Formation tends to contain more erodible sediments than the Tansil and Yates. Therefore, less bedrock is exposed where the Limestone Hills ESD occurs on the Seven Rivers Formation.

Deposited above the Seven Rivers during a quiet period within an unrestricted lagoon is the Yates Formation. The Yates is characterized by layers of very pale orange to yellowish-gray fine-grained, laminated dolomite, alternating with grayish-orange to pale yellowish-orange, calcareous quartz siltstone or very fine-grained sandstone. The Yates is the surface formation over much of Carlsbad Caverns National Park (CCNP), starting at Walnut Canyon and extending North through the Cueva Escarpment and up to Living Desert State Park.

Landward of the unrestricted lagoon was a restricted lagoon, (the Tansil Formation). Here freshwater mixed with seawater. Large amounts of sediments were carried in by streams causing a hostile environment for marine organisms. Like the Yates, the Tansil is characterized by clastic sediments such as siltstone and sandstone as well as layers of dolomite. Unlike the Yates, however, the Tansil contains many thin clay layers (Burger, 2007). The Tansil Formation is the surface layer at the Carlsbad Caverns Visitor Center.

About 15 million years ago, the ancient reef rock that had been buried by younger layers of rock began to rise, creating the Guadalupe Ridge and Mountains while exposing the Seven Rivers, Tansil, and Yates Formations. Over the years, at the hill slope positions, much of the more clastic layers of the Tansil, Yates, and Seven Rivers have eroded away, leaving the very shallow soils mixed and exposed dolomitic limestone rock outcrop which make up the Limestone Hills Ecological Site.

Ecological Site Key for LRU 42.8 and 42.9, Northeastern Chihuahuan Hills and Mountains

1. Site is within LRU 42.8, which is within the ustic-aridic soil moisture regime, and the thermic soil temperature regime. (Often contains redberry juniper)
2. Soils are loamy and not skeletal, and reside in low areas that are stream terraces and fan remnants. - Loamy Terrace ESD
2. Soils are skeletal (Greater than 35% by volume rock fragments greater than 2 mm)
3. Soils are deep to very deep. (Greater than 100 cm to root restrictive layer)
4. Site exists in an active floodplain.-Draw ESD
4. Site exists on a stream terrace or alluvial fan-Gravelly ESD
4. Site exists on steep slopes on limestone colluvium over gypsum residuum.-Limy Gyp Escarpment
3. Soils are very shallow to moderately deep (5-100 cm).
5. Root restrictive layer is a petrocalcic horizon.-Shallow ESD
5. Root restrictive layer is bedrock.
6. Slopes are less than 25%-Very Shallow ESD
6. Slopes are greater than 25%- Limestone Hills ESD
1. Site is located within LRU 42.9, and is represented by the aridic-ustic soil moisture regime, and the mesic soil temperature regime. (It often contains alligator juniper and pinon pine.)
7. Slopes are less than 25%- Shallow Limestone ESD
7. Slopes are greater than 25%- Limestone Mountains ESD

ESD Key Glossary
Glossary:

Colluvium: “Unconsolidated, unsorted earth material being transported or deposited on side slopes and/or at the base of slopes by mass movement (e.g. direct gravitational action) and by local, concentrated runoff” (Schoenberger, et al., 2012).

Petrocalcic Horizon: The petrocalcic horizon is an illuvial horizon in which secondary calcium carbonate or other carbonates have accumulated to the extent that the horizon is cemented or indurated (Keys to Soil Taxonomy, 2010).

Residuum: “Unconsolidated, weathered, or partly weathered mineral material that accumulates by disintegration of bedrock in place” (Schoenberger, et al., 2012).

Soil moisture regime: Refers to the presence or absence either of ground water or of water held at a tension of less than 1500 kPa in the soil or in specific horizons during periods of the year. Water held at a tension of 1500 kPa or more is not available to keep most mesophytic plants alive. Major differences in soil moisture are often reflected in different vegetative communities. The two major soil moisture regimes for the Guadalupe Mountains are Aridic and Ustic (Keys to Soil Taxonomy, 2010).

Soil Temperature Regime: This is the range of temperatures experienced by a soil at a depth of 50 cm. When the average temperature of a soil falls between 46 degrees F and 59 degrees, it falls into the mesic soil temperature regime. The thermic soil temperature regime falls between 59 degrees F and 72 degrees (Keys to Soil Taxonomy, 2010).

Table 2. Representative physiographic features

Climatic features

The mean annual precipitation is 10.4 inches to 18.3 inches, occurring mostly as high intensity, short-duration afternoon thunderstorms from July through September. Mean annual air temperature is 55 to 70 degrees F, and the frost-free season is 207 to 243 days.

Annual weather patterns, influenced by global climate events, such as El Nino and La Nina, affect and alter production and composition across the Limestone Hills Ecological Site. In general, because precipitation is minimal through the winter but increases during the summer, warm-season (C4) plants dominate the landscape. However, from year to year the production and composition can greatly shift due to variable weather patterns. The years that produce the most species richness and production are those that get slow, steady moisture through the months of May, June, and July. Late summer thunderstorms may induce heavy runoff on this site, creating flash-flooding in the draws, drainages, and canyons below.

The climate trend of the area is one toward warmer temperatures and lower precipitation. According to the Carlsbad Caverns Climate Station, during the years 2001-2011, five years received less than 10 inches of rain. Three of those years, (2003, 2005, and 2011) were below 5 inches of rain. And 2011 was both the lowest rainfall and hottest year on record. Similarly, in 1947-1957, 6 out of 11 years were below the mean low of 10.4 inches. But in that stretch, only one year, 1951, was below 5 inches. To put this in perspective, in the dry 1930’s only 2 years were below the mean low of 10.4 and none were below 5 inches. The 2001-2011 decade has been much warmer and drier than any in recorded history. In addition, during the two years of 2010 and 2011, Carlsbad Caverns National Park experienced extreme events of drought, wildfire, and flash flooding which have led to shifts in plant communities

Table 3. Representative climatic features

Influencing water features

The Limestone Hills Ecological Site is not associated with a wetland or riparian system; it is an upland ecological site.

Soil features

Every ecological site and associated soil component has static soil properties that help define the physical, chemical, and biological characteristics that make the site unique. The following soil profile information is a description of those unique soil properties for the Limestone Hills Ecological Site. To learn about the dynamic processes of the soil component, refer to the "plant communities" section of the ESD.

The Limestone Hills Ecological Site is tied to the Lechuguilla and rock outcrop components from map units CC2, CC9, LK1, RB1, and BL1 within LRU 42.8 Northeastern Chihuahuan Hills. The CC2 and LK1 map units are very similar, and consist of complexes of components which are dominated by about 70 percent Lechuguilla, 15 percent Kimrose, and 15 percent rock outcrop. The BL1 map unit consists of about 45 percent Bogle, 20 percent Lechuguilla, and 15 percent Badlands. The Lechuguilla component has formed from mostly colluvium and residuum which has been derived from limestone and dolomite parent material. Soil depth ranges from very shallow to shallow (20-40 cm) over bedrock.

In normal years this soil is driest during the winter. It is moist in the upper part for over 90 cumulative days, but fewer than 90 consecutive days during the growing season. The soil moisture regime is aridic bordering on ustic. The mean annual soil temperature is 59 to 66 degrees F, which is classified as the thermic temperature regime.

This soil is well drained with high runoff. At the surface, the saturated hydraulic conductivity ranges from 1.0 to 10 m/second over impermeable bedrock. The Lechuguilla taxonomic class is: Loamy-skeletal mixed, superactive, calcareous, thermic Lithic Ustic Torriorthents.

Typical Pedon: Lechuguilla hill slopes; Geographic Coordinate System: 32° 7'' 12.76'''' north, 104° 33'' 54.52'''' west

A1--0 to 2.5 inches (0 to 6 cm); brown (10YR 4/3) very cobbly loam, very dark grayish brown (10YR 3/2), moist; 20 percent clay; moderate coarse granular structure; soft, very friable, slightly sticky, slightly plastic; common very fine roots and common fine roots; common fine interstitial pores; 30 percent gravel and 15 percent cobble and 5 percent stone; violently effervescent, 33 percent calcium carbonate equivalent; moderately alkaline, pH 7.9; clear smooth boundary.

A2--2.5 to 9 inches (6 to 23 cm); brown (10YR 4/3) very gravelly loam, very dark grayish brown (10YR 3/2), moist; 22 percent clay; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine roots and common fine roots; common fine interstitial pores; 10 percent fine gravel and 5 percent coarse gravel and 10 percent cobble and 5 percent stone; violently effervescent, 29 percent calcium carbonate equivalent; slightly alkaline, pH 7.7; clear smooth boundary.

Bk--9 to 12.5 inches (23 to 32 cm); brown (10YR 5/3) very stony loam, very dark grayish brown (10YR 3/2), moist; 23 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; few medium roots and common very fine and fine roots; common fine interstitial pores; common fine prominent irregular carbonate masses throughout and few medium prominent irregular weakly cemented carbonate nodules on bottom of rock fragments; 10 percent fine gravel and 5 percent coarse gravel and 10 percent cobble and 15 percent stone; violently effervescent, 39 percent calcium carbonate equivalent; moderately alkaline, pH 7.9; abrupt smooth boundary.

R--12.5 to 78.5 inches (32 to 200 cm); indurated limestone or dolomite bedrock.

Typical Surface Fragments <=3" (% Cover): 20-30%

Typical Surface Fragments > 3" (% Cover): 20-30%

Typical Subsurface Fragments <=3" (% Volume): 20-30%

Typical Subsurface Fragments > 3" (%% Volume): 30-50%

Typical Soil Depth: 20-40 cm

Calcium Carbonate Equivalent (percent):
A & A2 horizons-0 to 5
Bk horizon-0 to 25

Total Average Available Water Capacity (cm H2O/cm soil): 2.73 cm

Table 4. Representative soil features

Animal community

Part 1: Wildlife

The Limestone Hills ecological site lies at the northern extent of the Chihuahuan Desert and provides habitat for many different wildlife species.

Species of special interest:

These are species of special interest that have habitat needs associated with the Limestone Hills ecological site.

Guadalupe Mountains Tiger Beetle: This beetle is endemic to the Guadalupe Ridge and Mountains and is tightly associated with limestone outcroppings (SWCA Environmental Consultants, 2007). Adults feed on just about anything they can see and catch, including invertebrates that may be larger than themselves. Their vision seems acute, as any movement (even by a human at a distance) causes them to turn and face the source of the motion. Beetles, flies, caterpillars, ants, grasshopper nymphs, and spiders are just a few of the invertebrates reported as tiger beetle prey. Although most tiger beetles are wary and not easily approached, they are also preyed upon. Predators of tiger beetles include dragonflies, robber flies, other tiger beetles, birds, and small vertebrates. Mites are also known to parasitize tiger beetles ( Spomer, Hoback, Golick, Higley, 2006).

Rock Rattlesnake: The rare mottled rock rattlesnake is found only in New Mexico, Texas, and Chihuahua, Mexico. In New Mexico, the rattlesnake is limited to the southern Guadalupe Mountains and exists within all canyons throughout the Guadalupe Ridge. It is the most frequently encountered rattlesnake in CCNP and is found around exposed bedrock where it feeds on lizards, snakes, and small mammals (SWCA Environmental Consultants, 2007).

Texas Horned Lizard: Horned lizards have habitat needs that require healthy harvester ant communities. Harvester ants are the preferred food of horned lizards and when this food resource declines due to shifts to a degraded plant community, or through infrastructure development, lizard numbers will also decline ( Henke and Fair, 1998). Feeding may occur at nest entrances or on ant foraging trails and mature lizards are capable of eating 70 to 100 ants per day. Although ants comprise a majority of the diet, Texas horned lizards are opportunistic predators and will consume crickets, grasshoppers, beetles, centipedes, bees and caterpillars. The diagnostic plant community phase (1.1) is best for providing a wide range of plant and insect species needed for Texas horned lizard habitat.

Gray Vireo: The gray vireo is found in the desert Southwest. Over 80 percent of the Gray Vireo territories in New Mexico are found in 12 sites, with the largest site being found in the Guadalupe Mountains (Pierce, 2007). The Gray Vireo appears to not winter in New Mexico but move down to the Big Bend area where it is associated with various shrubs and cacti. Summer habitat in the Guadalupe’s seems to be linked to juniper and oak plant communities at the upper end of the limestone hills ecological site (above 4300 feet). During breeding season, (April-July) the Gray Vireo are insectivorous, taking grasshoppers, stinkbugs, crickets, moths, and caterpillars for food. In New Mexico, nests are primarily in Juniper trees (Pierce, 2007). Plant communities within the historic range of variability are important for the Gray Vireo to find nesting, breeding, and brood-rearing cover. The birds will find nesting cover in plant communities 1.1 and 1.2, while moving to community phase 1.3 to find food.

Peregrine Falcon: The Peregrine Falcon is a species of concern that occurs throughout the west. According to experts at the “Living Desert Zoo and Gardens State park” in Carlsbad New Mexico, the peregrine falcon has only been spotted on a rare occasion in the fall or winter.

Common hog-nosed skunk: Hog-nosed skunks are distinguished from striped skunks primarily by the pelage, with a characteristic broad white marking beginning at the top of the head and extending down the back and tail. They make their dens in rocky areas within the Limestone Hills. They are omnivorous, and they eat differently according to the season. They mainly eat insects and grubs but also eat fruit, small mammals, snakes and carrion. Because rattlesnakes react to skunk musk with an alarm reaction, it is believed that skunks may feed extensively on rattlesnakes. In search of food, this skunk that roots can turn over large areas of earth with its bare nose and front claws as it searches for food (Buie, 2003).

Mountain Lion: The mountain lion is an excellent stalk-and-ambush predator, pursuing a wide variety prey. Deer make up its primary food source, but they will also hunt species as small as insects and rodents. The mountain lion stalks through shrubs and across ledges before delivering a powerful leap onto the back of its prey with a suffocating neck bite. The mountain lion is capable of breaking the neck of its prey with a strong bite and momentum bearing the animal to the ground. Kills are generally estimated at around one large ungulate every two weeks. This period shrinks for females raising young, and may be as short as one kill every three days when cubs are nearly mature at around 15 months.
Only females are involved in parenting. Females are fiercely protective of their cubs, and have been seen to successfully fight off animals as large as black bears in their defense. Caves and other alcoves that offer protection are used as litter dens (Cougar, 2013).

The Very Shallow and Limestone Hills ecological sites provide excellent habitat for the mountain lion life cycle. The abundance of shrubs in plant community 1.2 is ideal for lions to hide and stalk prey. Mountain lions can work the edge of hill summits and position themselves above prey where they can pounce with a killing blow.

Eastern White-throated Wood Rat: This large rat is often called a packrat because of the large nest of sticks and other material that it incorporates into nests. The nocturnal rat feeds on a wide variety of plants and finds shelter around dense stands of cacti such as cholla and prickly pear. Plant communities 1.1 and 1.2 are ideal for nesting white-throated wood rats.

Other species associated with the limestone hills ecological site:

Birds:
Turkey Vulture
Mississippi Kite
Red-tailed Hawk
American Kestrel
Great Horned Owl
Spotted Towhee
Canyon Towhee
Cassin’s Sparrow
Brewer’s Sparrow
Black-throated Sparrow
White-crowned Sparrow
Dark-eyed Junco
Scaled Quail
White-winged Dove
Mourning Dove
Eurasian Collared Dove (introduced)
Lesser Nighthawk
Common Nighthawk
Black-chinned Hummingbird
Ladder-backed Woodpecker
Western Kingbird
Cliff Swallow
Barn Swallow
Verdin
Cactus Wren
Rock Wren
Northern Mockingbird
Curved-billed Thrasher
House Finch
House Sparrow

Mammals:
Mexican Ground Squirrel
Yellow-faced Pocket Gopher
Merriam’s Kangaroo Rat
Merriam’s Pocket Mouse
Western Harvest Mouse
Southern Plains Woodrat
Cactus Mouse
White-footed Mouse
White-ankled Mouse
Hispid Cotton Rat
North American Porcupine
Black-tailed Jackrabbit
Desert Cottontail
American Badger
Striped Skunk
Grey Fox
Coyote
Bobcat
Mule Deer
Barbary Sheep (introduced)
Ringtail

Reptiles:
Green Toad
Red-spotted toad
Rio-Grande Leopard Frog
Eastern Collared Lizard
Greater Earless Lizard
Round Tailed Horned Lizard
Crevice Spiny Lizard
Prairie Lizard
Common Side-blotched Lizard
Texas Banded Gecko
Chihuahuan Spotted Whiptail
Common Checkered Whiptail
Ring-necked Snake
Striped Whip Snake
Western Ground Snake

Note: This species list was composed with help from the Living Desert Zoo and Gardens State Park, Carlsbad, New Mexico.

Desert Bighorn and Barbary sheep: By 1946 the desert bighorn was extirpated from the Guadalupe Mountains. Illegal hunting and excessive competition from livestock are the major culprits. Disease from livestock played a role as well.

Currently, there is an estimated 400-770 Barbary sheep in the Guadalupe Mountains. This species fills the niche that desert bighorn once held. There has been consideration given to re-introducing the desert bighorn, but this will most likely not happen unless the population of Barbary sheep can be reduced.

Barbary sheep are native to North Africa, and were released in the Hondo Valley, Largo Canyon, and the Canadian River drainage between 1955 and 1970. Viable populations have become established in historic bighorn habitat in the Guadalupe and Sacramento Mountains. They compete with desert bighorn due to their higher rate of increase, ability to subsist on lower quality forage, and preference for habitat similar to that of bighorn. Barbary sheep are socially aggressive when they encounter bighorn and may disrupt the rut (Goldstein and Rominger, 2003).

Part II Livestock:

The Limestone Hills Ecological Site has traditionally been grazed by all kinds and classes of livestock, during all seasons of the year. In the early part of the 20th century, goats and sheep were used extensively along the Guadalupe Ridge, taking advantage of browse species. Currently, though, there are very few goat and sheep operations in the area due to many market factors. Cattle numbers are in decline due to drought and extensive wildfire from 2001-2011.

With a planned livestock grazing and browsing system, the limestone hills ecological site could be managed for sustained agriculture while maintaining the historic range of variability. Prescribed fire may be used as a management tool to hold the plant communities within the historic range of variability.

Hydrological functions

The Lechuguilla soil component is in hydrologic group “D”; as are all soils that have a depth to impenetrable layer of less than 50 cm. Runoff from this site is common, especially during heavy rainstorms, because the soil is shallow and well drained. During heavy rain, once the soil is saturated, surface sheet flow is common. The severity of sheet flow depends on the plant community and the amount of gravel armoring. As the plant community changes from the historic range of variability to the “at risk” plant community, surface sheet flow increases due to a lack of vegetation and a decrease in soil aggregate stability.

Fire can temporarily change the soil surface chemistry, making it hydrophobic for a time and causing more sediment to move off site. It is important for vegetation to re-establish and provide structure for infiltration and organic matter for water storage.

Limestone has low permeability, but plant communities depend on deep cracks and fissures to hold soil, nutrients, and organic matter. In these deep cracks, organic matter acts like a sponge, storing water and keeping plants alive through dry periods. Deep cracks within bedding plains also act as conduits, moving water to plants rooted on a limestone terrace. Sometimes springs occur where bedding plains are exposed on hill sides.

Recreational uses

The Limestone Hills Ecological Site provides limited recreational use due to its lack of drinking water. Hiking is limited to day trips and should not be attempted without adequate water and a large hat. Hunting is common on this site, especially for mule deer.

Other information

Inventory data references

Data was collected during the years of 2011 and 2012. For all tier one data points, ocular methods were used to collect estimates of production, ground cover, and canopy cover. The Doman-Krajina method was used for canopy cover estimates. Soil pits were dug for verification on many tier one plots. Tier two and three protocols always were verified and analyzed with soil pits. Other methods used were line-point-intercept (LPI), double-sampling (DS), canopy gap (CG), and soil stability (SS). This ecological site had a number of tier one and tier two plots, with one tier three at the diagnostic plant community. Historic data from BLM monitoring points were used as well.

Type locality

Other references

Coauthors:

Aaron Miller-MLRA 70 Project Leader, NRCS
Logan Peterson-MLRA 70 Soil Scientist, NRCS

Special Contributors:

Steve Daly-Soil/Range Conservationist, Carlsbad Field Office, BLM
Herman Garcia-Ecological Site Inventory Specialist, Southwest Region 8, NRCS
Tracy Hughes-Range Conservation Technician, Carlsbad Field Office, NRCS
Darren James-Researcher, USDA, Jornada ARS

Reviewers:

Steve Daly-Soil Conservationist, Carlsbad Field Office, BLM
Herman Garcia-Ecological Site Inventory Specialist, Southwest Region 8, NRCS
Mark Moseley-Ecological Site Inventory Specialist, Texas Region 9, NRCS
Richard Strait-State Soil Scientist, New Mexico NRCS
John Tunberg-State Rangeland Management Specialist, New Mexico NRCS
Renee West-Biologist, Carlsbad Caverns National Park

ESD Workgroup:

Lu Burger-Natural Resource Specialist, State Office, BLM
Steve Daly-Soil Conservationist, Carlsbad Field Office, BLM
Samuel Denman-Cultural Resource Specialist, Carlsbad Caverns National Park
Garth Grizzle, District Conservationist, Area Range Conservationist, NRCS, retired
Charles Hibner-MLRA 70 SS Leader, NRCS, retired
Tracy Hughes-Range Conservation Technician, Carlsbad, NRCS
Laurie Kincaid-Rancher, Carlsbad
Michael McGee- Hydrologist, Roswell Field Office, BLM
Aaron Miller-MLRA 70 Project Leader, NRCS
Susan Norman-GIS Specialist, Carlsbad Caverns National Park
Logan Peterson-MLRA 70 Soil Scientist, NRCS
Mark Sando-Rangeland Management Specialist, Guadalupe District, USFS
Kent Schwartzkopf-Chief, Stewardship and Science Div., Carlsbad Caverns National Park
Renee West-Biologist, Carlsbad Caverns National Park
Pete Biggam-Soils Program Manager, National Park Service, Lakewood Colorado



References:

Ahlstrand, G., 1981. Ecology of fire in the Guadalupe Mountains and adjacent Chihuahuan Desert. Carlsbad(New Mexico): Carlsbad Caverns and Guadalupe Mountains National Park.

Bestelmeyer, Moseley, Shaver, Sanchez, Briske, and Fernandez-Gimenez, 2010. Practical Guidance for Developing State-and-Transition Models. Rangelands, p. 26.

Buie, L., 2003. Hog-nosed skunk. [Online]
Available at: http://itech.pensacolastate.edu/sctag/hn_skunk/index.htm
[Accessed 26 10 2012].

Burger, P., 2007. Walking Guide to the Geology of Carlsbad Cavern. Carlsbad, NM: Carlsbad Caverns and Guadalupe Mountains Association.

Burkett, B. a. T., Version 1.1. A Field Guide to Pedoderm and Pattern Classes, Las Cruces, New Mexico: USDA-ARS Jornada Experimental Range.

Cleland, D. T. et al., 2007. Ecological Subregions: Sections and Subsections of the Conterminiuos United States.. s.l.:United States Forest Service.

Cougar. (2013, September 8). In Wikipedia, The Free Encyclopedia. Retrieved 21:37, September 19, 2013, from http://http://en.wikipedia.org/w/index.php?title=Cougar&oldid=571991990

Duniway, Bestelmeyer, Tugel, 2010. Soil Processes and Properties That Distinguish Ecological Sites and States. Rangelands, pp. 9-15.

Gebow, B. S., 2001. Search, Compile, and Analyze Fire Literature and Research Associated with Chihuahuan Desert Uplands, Tuscon: The University of Arizona.

Goldstein and Rominger, 2003. Plan for the Recovery of Desert Bighorn Sheep in New Mexico, Santa Fe: New MExico Department of Game and Fish.

Henke and Fair, 1998. Management of Texas Horned Lizards, Kingsville, Tx.: Caesar Kleberg WIldlife Research Institute.

Herrick, et al., 2001. Soil aggregate stability kit for field-based soil quality and rangeland health evalutations.. s.l.:s.n.

Kayser, D. W., 2010. Prehistory: SHort and Seet. "Different peoples over a long period of time vistied, used the abundant resoruces or lived here at CASVE.", s.l.: s.n.

Kelley, V., 1971. Geology of the Pecos Country, Southeastern New Mexico. s.l.:New Mexico bureau of Mines and Mineral Resources.

Keys to Soil Taxonomy; United States Department of Agriculture, Natural Resources Conservation District; Eleventh Edition; 2010

New Mexico Game and Fish, n.d. Wildlife Notes-Ringtail, s.l.: New Mexico Game and Fish.

Pellant, Pyke, Shaver, Herrick, 2005. Interpreting Indicators of Rangeland Health. Version 4 ed. Denver(CO.): United States Department of the Interior, Bureau of Land Managment, National science and Technology Center, Division of Science Integration.

Pierce, L. J., 2007. Gray Vireo (Vireo vicinior) Recovery Plan, Santa Fe, NM: New Mexico Department of Game and Fish.

Schoeneberger, P.J., and Wysocki, D.A. 2012. Geomorphic Description System, Version 4.2. Natural Resources Conservation Service, National Soil Survey Center, Lincoln, NE.

Spomer, Hoback, Golick, Higley, 2006. Biology, Lifecycle, and Behavior. [Online]
Available at: http://drshigley.com/lgh/netigers/index.htm
[Accessed 26 10 2012].

SWCA Environmental Consultants, 2007. Carlsbad Caverns National Park, Environmental Assessment, s.l.: U.S. Department of Interior.

United States Department of Agriculture, Natural Resources Conservation Service, 2006. Land Resource Regions and Major Land Resource Areas of the United States, the caribbean, and the Pacific Basin. s.l.:s.n.

Contributors

Scott Woodall