By A. Thomas Cole*
Despite their unique and rare place in the American Southwest, little is known about ciénagas. Depending on which scholar you ask, there were many hundreds, if not thousands ⎯ in what can be thought of as the International Four Corners Region of Arizona, New Mexico, Sonora, and Chihuahua⎯ before European arrival. Recognition and numbers of their smaller cousin, Sumideros, are essentially lost.
The spelling, pronouncing, and etymology of the word “ciénaga” is a complex account beyond the scope of this writing. Suffice it to say the word is derivative of the Spanish term for “silt,” (cieno) properly spelled with either a second “e” or an “a,” the former more common but a lesser choice. Ciénaga also requires a tilde (é), although it’s commonly omitted.
Ciénagas are desert marshes, alkaline, freshwater, spongy, wet meadows with shallow-gradient, permanently saturated soils in otherwise arid landscapes. These unique arid-land wetlands are commonly associated with seeps or springs, found in canyon headwaters or along margins of streams. Ciénagas often occur because bio morphology forces water to the surface, over large areas, not merely through a single pool or channel. In a healthy ciénaga, water slowly migrates through long, wide-scale mats of thick, sponge-like wetland sod. Before Spanish arrival, ciénagas often occupied the entire widths of valley bottoms, a description that explains historic, pre-damaged ciénagas, few of which can be described that way today. The blue-lined photograph illustrates where the portion of the Burro Ciénaga on the Pitchfork Ranch south of Silver City, New Mexico flowed before it was damaged.
Ciénaga soils are squishy, permanently saturated, highly organic, silty, black in color, anaerobic. Highly adapted sedges, rushes and reeds are the dominant plants, with succession plants—Gooding’s willow, Fremont cottonwoods and scattered Arizona walnuts—found on drier margins, down-valley in healthy ciénagas where water goes underground or along the banks of incised ciénagas. Although trees drown in historic ciénagas—that’s why “swamp” is a common miss-description, because swamps have trees—these woody plants now occupy many damaged or drained ciénagas. The earlier photograph just above is the willow-lined Pitchfork’s ciénaga, after removal of cattle.
Undamaged ciénagas, essentially nonexistent today, were characterized by a slow-moving, broad flow through extensive emergent vegetation as just described. But today, the ongoing region-wide erosion that followed the arrival of Europeans in the American Southwest and the subsequent misuse of the land by settlers firmly entrenched water flow between vertical walls, resulting in an ever-worsening incision process. This drawdown of local water tables and the drying of up to 95% of these marshland environments has left behind few undamaged ciénagas. As shown here, many that remain today look and function like the Pitchfork’s ciénaga, similar to a creek: narrow, incised and continuing to degrade. Since the 1870s, natural wetlands in arid and semi-arid desert grasslands of the American Southwest and Northern Mexico have largely disappeared.
Although under-recognized, ciénagas have been important since forever. Many prehistoric agricultural settlements were located near ciénagas or on the floodplains of the major perennial streams where irrigated agriculture could be practiced. Abundant archeology surrounds many ciénagas; they hold data about Native American land use; contain fossil remains of prehistoric animals now extinct; proxy data such as pollen, charcoal and isotopes preserved in ciénaga sediment that are now cored and studied. This appears to be the best way to uncover the history of the Southwest as “keystone ecosystems,” they have a vastly disproportionate relevance to their surroundings; and, not unimportantly, there is their beauty. It was not until 1985 that a professor and would-be ichthyology student wrote a paper that alerted the academic world in the Southwest to the importance of its overlooked ciénagas. So called “progress” often led to the now abandoned thinking: the only good wetland was a drained wetland, to be emptied, improved and developed. Over the last four decades, efforts to inventory, evaluate as to condition, understand and restore ciénagas has gradually gained prominence.
Their importance is hard to overstate. Ciénagas are critical for birds and other animals because more than 70 percent of land animals use riparian areas. Wetlands in the Southwest occupy under two percent of the land area and have an exorbitant impact on the region; wetlands are critical habitat for species that are at risk; at least 19 percent of Arizona’s endangered, threatened or candidate species for protection are dependent on wetland environments. Providing wetland habitat in otherwise arid regions, desert ciénegas and riparian corridors have the potential to increase regional biodiversity by up to half.
Ciénagas also a source for “ecosystem services,” an emerging restoration notion in which market value is attributed to various environmental functions provided by landowners for the public good and for which they have historically not been compensated: filtering rain and snowmelt; slowing seasonal flood pulses; reduce stream channel degradation and otherwise slow soil erosion; promoting groundwater recharge; and delivering clean, safe drinking water at a far lower cost than it would take to build infrastructure to replace these services.
A nearly forgotten indication that there was far more water in the Southwest and suggesting there were more ciénagas here than we’ll ever know is the sumidero. The word in standard Spanish means a sewer, drain or gutter, but to early settlers and ranchers it meant a mask well or sinkhole. They were dangerous, 10 to 20 feet across, deep traps that showed up unexpectedly on plains or alkali-covered flats that consisted of too much mud to flow and too much water to dry up. The thin, upper mud surface of a sumidero was baked dry, absent any indication to distinguish it from nearby safer ground. If a man, horse, or cattle stepped onto the treacherous surface of a sumidero, like quicksand, they could instantly perish without ever being recovered. Old tales persist of cowboys and animals being sucked into the mud under the crisp surface of sumideros. These dangerous features of an arid Southwest are long gone but offer insight into the future of ciénagas if there is not a concerted effort to save these remaining forgotten waters.
In less than 200 years, a series of mostly human-caused events conspired to transform the Southwest from a depositional environment to an erosional one, severely lowering groundwater tables, drying the land and resulting in a bewilderingly high number of ciénaga losses. This period can be thought of as “The Great Ciénaga Disappearance.” What nature painstakingly assembled over a period of some 10,000 years humans nearly destroyed in less than 200 years. Most ciénaga habitat has simply disappeared, leaving only a “skeleton” or thin stream of water that, absent a concentrated restoration effort, will soon blink out.
There are those who maintain that the main impact on the ecology of the Southwest was the introduction of large-scale cattle ranching in the 1880s, but the disappearance of ciénagas and general drying out of the Southwest is far more complicated than the over stocking of cattle. Ciénaga disappearance began with the arrival of Spanish livestock, but the dominant animal was sheep, not cattle. The search for the Seven Cities of Gold failed, but Spain’s hunt for wealth persisted as sheep—trampling ciénaga banks, disrupting the habitat and over-using water— became the dominant domestic animal in Spain’s northern frontier. By the 1820s as many as two million sheep covered New Mexico, and, by 1865, the numbers of sheep more than doubled with a ratio of sheep to cattle ballooning to 37 to 1 or 4,600,000 sheep to only 125,000 head of cattle.
Ciénaga dewatering continued with the over-trapping of beavers in the 1820s. In a surprisingly short period, beavers were virtually eradicated from the American Southwest. Beaver dams soon failed from neglect, and channels began to form in the soft sediments trapped behind these barriers. Over time, the channels became increasingly connected and the process of channeling, down-cutting and dewatering of ciénagas took hold. Shallow, flatland watercourses and adjacent riparian zones shifted from complex systems dominated by ponds, multiple channels, ciénagas, marshes and otherwise wide wetlands plentiful in fish and wildlife into simple, incised, single-thread channels with narrow strips of riparian vegetation. Beavers—said to be “landscape-shaping creatures,” an indispensable creator of ecosystems that foster entire ecological communities—are capable of building as many as twenty dams per mile of stream, smear water across the landscape in a series of broad pools and mucky wetlands linked by shallow, multiply branched channels.
Many ciénagas suffered further damage when early settlers re-contoured the broad ciénaga canyon flats in a misguided attempt to prevent the flooding of their agricultural fields. Remnant ditches, dikes and dams persist today throughout many of the abandoned canyon fields near some of the few remaining and poorly functioning ciénagas. The resulting channelization and concentrated water flow have reduced these historic wetlands to a fraction of their original size and have inadvertently created deep, high-walled incisions that have progressively worsened—though most farming has long-since ceased—and exacerbated the region-wide lowering of the groundwater table, further dewatering formerly wetted ciénagas.
The damage to ciénagas caused by sheep, followed by the decimation of beaver and the conversion of open land to agricultural fields was then worsened with the overstocking of cattle and the dramatic increase in cattle numbers by the 1880s. Ciénagas were trampled and dewatered, stream banks caved, grasslands neutered and erosion accelerated. While the ratio of sheep to cattle was 37 to one a mere 25 years earlier, by 1890, cattle numbers had spiked and the ratio narrowed to nearly two to one and ultimately flipped in favor of cattle, fifteen to one.
The severe weather and drought of the late 1880s and early 1890s exacerbated the degradation of the re-contoured and overstocked landscape devoid of beavers that had already seen grass and wetlands severely degraded. The weather worsened as mild winter rains and unusually dry summers peaked with two years of drought in 1891-3, bringing disaster with livestock mortalities reaching 75 percent. Springs and ciénagas long thought to be permanently wetted went completely dry. House-high piles of cattle bones and a severely damaged landscape scarred the Southwest and foretold the losses to be suffered by future generations. Throughout, the persistence of drought and uneven rains of these arid lands persisted, now accelerating, as human-caused climate change has the Southwest in its cross-hairs.
Compounding the over-trapping of beaver, over-stocking of sheep and cattle, the draining and conversion of land for agriculture, and drought, fire suppression by European arrivals may have caused as much harm as these others combined. Caused by lightning originating in pre-monsoonal thunderstorms and from purposeful ignition by Native Americans, fire was a significant influence in the evolution of southwestern ecosystems in which many plant species are fire-adapted. But since the arrival of Europeans in the Southwest, fire has been suppressed to such an extent—on average from occurring every 8 to 10 years to occurring almost never, except for forest fires—that woody plants have out-competed grasses and transformed historic grasslands into a landscape dominated by trees and shrubs. The majority of grass biomass consists of roots that lie beneath the surface while trees and other woody plants is the opposite, above ground. Before the arrival of Europeans, Southwest grassland fires occurred so often that they killed many woody plant species, yet merely topped off and strengthened the health of grasses. This frequent fire regime was a long time, natural intervention allowing grasses to out-compete woody plants. The transition from grasslands to woodlands helped finish off many ciénagas and severely reduced the size of those remaining.
There is yet another benefit of this unique arid-land water. The climate, biodiversity loss and companion crises have humankind ensconced in the most precarious, most important moment in human history.
With fire chasing Hawaiians into the ocean at a-mile-a-minute or 60-miles an hour, we no longer need to concern ourselves with the question of whether or not civilization is at risk, rather now the question is what can each of us do to avoid being the first species to document its own extinction. We are entrenched in boiling, cauldron-like weather, the search for solutions beyond abandoning the carbon-spewing, fossil-fuel merry-go-round has arrived. The transition from progress to stability is mandatory.
A consortium of 19 universities and other organizations released a 2017 study that contends the most mature carbon dioxide removal method of excess atmospheric carbon⎯the main culprit of our overheated climate⎯is improved land stewardship, better stewardship of land is needed to achieve the Paris Agreement goal of holding warming below 2°C. The report identified 20 natural-climate solutions, conservation, restoration and land management actions that increase carbon storage and or avoid greenhouse gas emissions across global forests, wetlands, grasslands and agricultural lands. This may be the first time a specific number has been attributed to this potential: natural-climate solutions can provide up to 37% of cost-effective CO2 mitigation needed through 2030 for a greater than 66% chance of holding warming below 2°C.
What, you ask, does this have to do with ciénagas? Another recent science paper maintains that wetlands like bogs, marshes and ciénagas capture up to 5 times more atmospheric carbon than forests and 500 times more than oceans. Simply put, habitat restoration and restoring ciénagas is not only a way to keep the Southwest healthy for wildlife, it’s also a way to drawdown excess atmospheric carbon. The United States Geological Service has surveyed and mapped the United States to identify which habitats can best store carbon and has explored ways to encourage their capability. A 2021 study published in the journal Nature Sustainability found that nature hoards climate-warming carbon in a small percentage of the Earth’s lands. “Irrevocable carbon”—defined as carbon that cannot be drawn down by 2050 if emitted in the atmosphere—is squeezed into a mere 3.3 percent of the Earth’s land area, mostly in peatlands, mangroves and old-growth forests.
This is a good place to recall Aldo Leopold’s ethic about how to live responsibly on this planet of finite resources and a way of life necessary for humankind to persevere:
“Examine each question in terms of what is ethically and esthetically right,
as well as what is economically expedient. A thing is right when it tends to preserve
the integrity, stability, and beauty of the biotic community. It is wrong when it tends
otherwise.”
Recall, Leopold said: “The only progress that counts is that on the actual landscape of the back forty” and warned:
“The government cannot buy ‘everywhere’…The private landowner must enter
the picture…The basic problem is to induce the private landowner to conserve his
own land, and no conceivable millions or billions for public land purchase can alter
that fact, nor the fact that so far, he hasn’t done it.”
*A. Thomas and Lucinda Cole retired to the Pitchfork Ranch south of Silver City, New Mexico where they have been restoring the portion of the Burro Ciénaga on the ranch and surrounding habitat since 2004. For a 5-minute video explaining ciénagas, go to Video about Aridland Ciénagas A.T. has also written Restoring the Pitchfork Ranch: How Healing a Southwest Oasis Holds Promise for Our Endangered Land to be published by the University of Arizona Press in February, 2024. To learn more about the ranch, ciénaga, and book, go to the ranch website: pitchforkranchnm.com where you can find information about the ranch, its wildlife, archaeology, restoration and other information, read excerpts from the book, blurbs and preorder.