Tuesday, October 11, 2011

A Rich Sparseness


“Water, water, water…There is no shortage of water in the desert but exactly the right amount, a perfect ratio of water to rock, of water to sand, insuring that wide, free, open, generous spacing among plants and animals, homes and towns and cities, which makes the arid West so different from any other part of the nation. There is no lack of water here, unless you try to establish a city where no city should be.”

- Edward Abbey, Desert Solitaire

Going to the desert to study water might at first glance seem strange, but where else would this study be of more use? The springs strewn so sporadically across the “wasteland” of the Southwest are literal oases, hotspots of biodiversity in the desert landscape and home to many rare, endemic species. And as the dense human populations of the arid states grow ever denser, causing the water tables to drop lower and lower, the fate of these life-sustaining water sources is increasingly uncertain.

I made my way out to Las Cruces, NM in August to begin work for the Chihuahuan Desert Inventory and Monitoring program, a National Park Service Directive. The I&M program tracks the state of natural resources within the park system, initiated by an Inventory of these resources, and followed with regular Monitoring surveys continuing indefinitely. 

Hiking to a spring in Big Bend National Park.
Note the bright patch of green above the crew's heads. That's the spring.
(There's a smaller spring to the right.)

A variety of floral, faunal, climatic and geologic I&M surveys have been instituted, but ours is concerned with water sources (springs, wells, seeps, etc.) found in the Chihuahuan Desert. Still in the initial inventory phase, we are preparing a database of information to guide future monitoring programs by collecting vegetation, aquatic macroinvertebrate and general habitat data.


For the purposes of the program, the Park Service has divided the park system into 32 ecoregional networks (see map above). The Chihuahuan Desert Network is composed of seven parks, including Carlsbad Caverns, Guadalupe Mountains, and Big Bend National Parks. (The network has also been contracted by the U.S. Fish and Wildlife Service to conduct sampling in some National Wildlife Refuges in the Southwest, so we get to go to those, too!)

Not all of the springs are remote -- one of our springs in the San Andres NWR used to be quite the popular picnic area back in the '40s and '50s. A big draw was surely the spring-fed swimming pool shown above, which was built by the CCC. 

The Chihuahuan Desert

The most biologically diverse desert in the Western Hemisphere and the largest in North America, the Chihuahuan Desert ecoregion is over 270,000 square miles and straddles the border between the United States and Mexico, reaching from just south of Albuquerque to just north of Mexico City. The multitude of habitats occurring within its extent – high elevation oak-pinyon-juniper woodlands, mid-elevation grasslands, low desert scrub, the gypsum dunes of White Sands National Monument— contributes to its startling diversity and makes it a veritable playground for the wandering amateur botanist.

A Fishhook Cactus erupting into spectacular bloom

Considered a “high desert,” much of the Chihuahuan lies above 4,000 feet, though it ranges from 1,000-10,000 feet across the whole expanse of the region. This high elevation (relative to other deserts like the Sonoran) means that winter temperatures drop below freezing fairly often, but trust me, the summers are still HOT, especially at low elevations. In fact, many of the springs we’re sampling now were not done during the past field season (spring and summer) because temperatures in Big Bend were simply too high to send crews out in.

Our camp at Big Bend was near the white house in the center of the frame. Note the large green patch on the right. Yep, that's a spring. They're quite easy to spot in the desert, if they're not dry (which many of them are).

My first few days of real work were in the beautiful San Andres National Wildlife Refuge. Due to the Refuge's location adjacent to the White Sands Missile Range (which houses, among other top-secret sorts of things, a NASA Test Facility), we had to be escorted to our sites and one day even acquired security clearance badges. (I'm pretty sure some of those jack rabbits were robots, too.) But any hassle was quickly forgotten once I got to my first desert spring. After a long, incredibly bumpy ride amid miles of desert scrub, a short hike brought us to a small brook where Flame Skimmers darted playfully among us, and cattails stood a stoic guard on their swampy feet. 

Flame Skimmer (Libellula saturata)


Golden Spur Columbine (Aquilegia chrysantha)

Once us newcomers got familiar with the protocol, and had learned enough of these new plants to get by, it was off to the Guadalupe Mountains to finish up training week. You might not think that the desert could offer that much of a botanical challenge, but I was learning new plants (and still am) at a rate that only heat, spines and job security could dictate.

Skyrocket, Scarlet Gila (Ipomopsis aggregata)
in the Gila Wilderness


I don't get creeped out by too many insects, but this centipede, at about 7 inches long, made me look around extra carefully before I sat down to eat lunch that day. It's a Scolopendra,
I think the species is polymorpha


This job has taken me to places few ever visit (or are even allowed to, in the case of the Wildlife Refuges), and has really given me a sense of the importance of these springs in a desert ecosystem. And aside from their integral ecological role, many of them are incredibly beautiful.


Wandering in the heat
One pace only gets you so far
And nowhere, really

Ashes of the mountains
His discarded progeny
Litter the ground and make violent attempts
To enter eye and mouth

A break in the monotone frame
A flash of green, too verdant to comprehend
And the ground grows softer
The spines sparser
The trickle of life sounding so sweetly on the ear
Amazed to see a shadow longer than your own


Sarcostemma sp., a twining member of the Milkweed family


My first real tour was in Big Bend National Park, in Texas. There is really no other adjective that could rightly be a part of that name. It is, first of all, literally massive. Over 800,000 acres. But beyond this quantitative measure, Big Bend is simply expansive, grand in every sense of the word. A harsh place to live, yes, where summer temperatures at low elevations are regularly over 100° F and water is scarce. But climb atop a ridge or mesa, or better yet, hike into the Chisos Mountains, and the vista painted before you is unequaled in splendor—beige plains stretching into the distance, interrupted by rocky arms and hands reaching for the heavens; red canyons carved into the bedrock, worn smooth by a million years of obstinate water; the 1500-foot Sierra Ponce cliffs that lie on the parks southern border, at whose feet meanders the Rio Grande, marking the northern edge of Mexico. (I know, you're saying, "Well where's the picture?" I have yet to capture a satisfactory shot that really would show you what I mean...still trying, though.)

Looking down on a particularly massive spring system in Big Bend. (Those are very large trees, it's just that I'm very high up.) You can see evidence of drying in the patch of dead cottonwoods downstream.





Not all of the water sources we inventory are natural. A good number of them are man-made or have had their flow altered by ranchers and other folk trying to make a living in the desert. We come across many windmill-powered wells like this one, with large holding tanks at their bases. Studies have shown that these anthropogenic repositories of water are very important to wildlife.


At this old (and dry) well site, a bereaved ranch hand painted his steed's epitaph on the side of this holding tank in 1950.



Next time we’ll head to the Sevilleta National Wildlife Refuge, explore what exactly makes a desert a desert, and look at some of the remarkable adaptations desert organisms have that allow them to persist in such a harsh landscape.

A horny toad spotted in the Gila Wilderness

Cheers,

john