SONORA CHRONICLES #1
(This is the first of what I intend will chronicle my travels and research in the Mexican state of Sonora as I investigate the impact of climate change and the water crisis in the transborder West.)
Published in the special issue of Surveys and Perspectives Integrating Society and Environment, examining large-scale land restoration projects around the world. See: http://sapiens.revues.org/1553
Abstract
Cuenca Los Ojos (CLO) is a private organization dedicated to large-scale restoration of degraded arid and semi-arid ecosystems. Incorporated both in Mexico and in the United States, CLO has land-restoration projects that span 748 square kilometres in the Mexico-U.S. borderlands region. This case study focuses on CLO’s restorative operations on the Mexican side of this increasingly fortified border region. It examines the progress, shortcomings, and challenges of the restoration underway on the 10 000 hectares of Rancho San Bernardino, which abuts the international border in northeastern Sonora. CLO’s achievements over the past 15 years — in controlling erosion, refilling and vegetating deeply incised arroyos, increasing surface and subsurface water, and expanding biodiversity — point to the value of considering the Rancho San Bernardino experiment as a global model. That this experiment has coincided with a prolonged drought also marks it as a model for drylands restoration in the hotter, drier conditions predicted with climate change. Similar large-scale restoration projects might also benefit from a review of CLO’s strategies for fostering cross-border cooperation, building multisectoral alliances among private and governmental participants, restoring transborder wildlife corridors, and creating links between land restoration and emerging restoration economies.
The
restoration of arid and semi-arid ecosystems merits increased global attention
because of their global expanse — constituting at least 40% of the planet’s
land surface — and accelerating degradation (Adeel et al., 2005;
FAO, 2001; Lal, 2005). But there is no consensus on a clear path forward — in
part because of the scarcity of models and in part because of the vigorous
debates about restoration and degradation thresholds (Bestelmeyer et
al., 2013).
When
targeted landscapes span fortified international borders or zones characterized
by widespread illegal activity, the complexities and challenges of drylands
restoration strategies are compounded. A case study of such a situation is
described here: Cuenca Los Ojos (CLO) is restoring severely altered riparian
areas and aridlands on the Mexico-U.S. border. At a time when the U.S.
government is fortifying its southwest border, CLO is advancing an alternative
paradigm that advocates restoring transborder ecosystems and generating
sustainable cross-border economies.
The
Cuenca Los Ojos foundation is a nonprofit project created by Valer and Josiah
Austin whose institutional mission is “to preserve and restore the biodiversity
of the borderland region through land protection, habitat restoration, and
wildlife reintroduction”.
The
Austins moved from New York City in 1983 to begin ranching in southeastern
Arizona. The El Coronado Ranch, which is situated on the western flanks of the
Chiricahua Mountains in the borderland area, was badly eroded and overgrazed,
prompting the Austins to reduce cattle grazing and initiate land-restoration
projects. Their restoration strategy primarily involved erosion control and
water harvesting techniques on their Arizona ranches, which encompass some 32
000 hectares.
Traces
of pre-Columbian indigenous communities remain throughout the transborder
region in the form of thousands of trincheras (rock check
dams), primarily used to increase cultivable land and to ensure year-round
supplies of drinking water, while also stemming erosion.
Although initially the Austins relied almost exclusively on trincheras for
erosion control and water harvesting, over the past fifteen years they have
also been erecting larger erosion control structures built with gabions
(rock-filled baskets formed by a mesh of galvanized wire). Gabion check dams
function like trincheras in trapping water-borne sediment
while slowing down the rush of storm water down arroyos and streams. Also like trincheras,
gabion dams eventually fade into the landscape as they become covered by
alluvium and vegetation. Since the early 1980s, the Austins estimate they have
erected more than 40,000 trincheras, earthen berms, and gabions on
their U.S. and Mexico properties.
Institutionalizing
their commitment to land restoration, the Austins founded Cuenca Los Ojos
(meaning “basin of springs”) and the civil association Cuenca Los Ojos, A.C. in
Mexico. CLO is the institutional instrument to manage their restoration
projects and to attract funds to maintain this restoration work. Recognizing
that their vision of reviving regional biodiversity and wildlife corridors
couldn’t be fully realized without restorative projects south of the border,
the Austins purchased Rancho San Bernardino in 1999, and they currently own 42
500 hectares along Mexico’s northern border.
CLO
has launched its restoration projects in a continental biodiversity hotspot.
CLO’s properties encompass all the ecosystems of a region variously described
as the Apache Highlands (Marshall et al., 2004) and the Mexican
Highlands (Woodward & Durall, 1996). Principal vegetation associations
include Chihuahuan desert scrub at 1100 m to pine–oak forests at 2500 m in the
Sierra San Luìs (Marshall, 1957). The discontinuous mountain ranges that span
the border along the north-south continental divide are known as the Sky
Islands or Madrean Archipelago.
CLO
manages land restoration projects on five ranches in Mexico that form a nearly
unbroken 22 km stretch of borderland, extending east from the San Bernardino
Valley into the northern outcrops of the Sierra Madre Occidental. These ranches
had been heavily grazed since the 1820s with the creation of the San Bernardino
Land Grant (C.O. Minckley, 2013) and especially after the beginning of
large-scale cattle ranching by Anglo-Americans and fire exclusion in 1870 (Bahre,
1991). Farming in the San Bernardino Valley using water from artesian wells
also resulted in the steady encroachment of woody desert shrubs (largely
mesquite and creosote) over the largely brush-free grasslands of the ciénaga
that historically spanned this transborder ecoregion.
Rather
than concentrating its resources on restoring and conserving the most
biodiversity-rich and scenic of its Mexico properties in the Sierra San Luìs,
CLO made the strategic decision to focus its resources on Rancho San
Bernardino, which was the most severely degraded of its Mexico borderland
ranches (V. Austin, personal communication).
1Rancho San Bernardino sits at the junction of the Sonoran and
Chihuahuan Deserts and the Mexican subtropics and the Great Plains grasslands
(Spector, 2002). The headwaters or important tributaries of the Río Yaqui pass
through Rancho San Bernardino and other CLO’s Mexico properties. The Río Yaqui
is the largest river system west of the Continental Divide in northwestern
Mexico and flows nearly 400 miles southwest through Sonora, finally emptying
into the Sea of Cortez. Rancho San Bernardino provides a valuable opportunity
to assess both riparian and grassland restoration. The San Bernardino Ranch and
the adjacent San Bernardino National Wildlife Refuge on the north side of the
border encompass the uppermost extent of the Río Yaqui watershed, and
subsurface pumping of the aquifer is not practised elsewhere in this area.
Overgrazing,
alfalfa farming, and gravel mining on the ranch and around its perimeter since
the late 1880s dramatically degraded the landscape and lowered the water table
by as much as 9 m in some sections (R.L. Minckley, 2013; Minckley &
Brunelle, 2007). Soon after the Austins purchased Rancho San Bernardino, CLO
removed the cattle and began its extensive erosion control projects. CLO’s
Rancho San Bernardino restoration project is a natural landscape scale
ecological experiment, which aims to return areas that are currently hardpan
scrublands to their former status in the mid-1800s as a mosaic of grassland,
desert, and riparian habitat (Bahre, 1995; Marrs-Smith, 1983; Humphries, 1987).
CLO
targeted Rancho San Bernardino for two main reasons: 1, to demonstrate how
closely monitored erosion control techniques can restore surface water flows
and groundwater reserves even in a landscape sundered by deeply incised
channels, and 2, to restore the critical function of the San Bernardino Valley
in the sustainability of the Río Yaqui watershed and associated transborder
wildlife corridor.
The
successes, shortcomings, and challenges of the restoration projects on Rancho
San Bernardino are instructive for possible future restoration projects in the
imperiled desert habitats of the U.S.-Mexico transborder West. This case study
can also point to the possibilities of successful cross-border restoration
efforts in conflictive drylands regions around the planet.
CLO
is simultaneously pursing a wide range of restoration techniques on Rancho San
Bernardino including the installation of a variety of erosion control
structures, cultivation of native grasses for seed, restoration of grasslands
through shrub removal and planting native grasses, and fostering biodiversity.
CLO is also leading the way forward in Mexico with respect to advocating the
use of prescribed burns in sustainable land practices. U.S. Fish and Wildlife
Service refuge manager Radke, 2013) reported that, "Grassland restoration
is being accomplished through prescribed burning and removal of invasive
mesquite trees, providing benefits to resident and migratory wildlife"
(p.6).
CLO’s
primary focus, however, is on restorative strategies intended to facilitate the
filtration of water into the soil, thereby recreating a historical landscape
characterized by perennial surface flows, a vast cross-border ciénaga,
and groundwater that can be tapped by native desert grasses.
Valer
Austin, who directs CLO’s restoration efforts in Mexico, has relied primarily
on empirical knowledge gained by fifteen years of erosion control and
water-harvesting efforts on the Austins’ ranches north of the border. The
restoration techniques on Rancho San Bernardino have also been informed by
close observation of the conservation and restoration practices on the two
USFWS refuges that adjoin CLO properties. On a February 6, 2012 visit to CLO’s
Mexico ranches, Valer Austin stresses that the key to successful land
restoration is the acquired ability to “read the land” and observe how humans
and forces of nature have altered the landscape. This empiricism also includes
“an unwavering determination to get sustainable land management right, and to
be constantly learning from your mistakes” (V. Austin, personal communication).
CLO,
however, is committed to the scientific evaluation of its restoration projects,
and has collaborated with scores of researchers and scholars from U.S. and
Mexican institutions. In its mission statement,
CLO stresses its commitment to “scientific research and sustainable resource
management techniques”, and it has hosted more than 100 researchers at its
ranch headquarters. Rancho San Bernardino is becoming a focal point of
research about the drylands restoration, including the effectiveness of gabion
dams.
The
erection of erosion control structures has a long history marked by many
failures (Peterson & Hadley, 1960; Peterson & Branson, 1962), and some
environmental experts warn that check dams and gabions should have no place in
stream and land restoration, noting that extreme weather events regularly
destroy well-intentioned erosion control structures, resulting in greater flood
damage (Zeedyk & Clothier, 2012).
There
is no playbook of large-scale drylands restoration that CLO could depend on to
guide much of its work, especially with respect to erosion control and
aggradation of deeply incised channels. Gabion dams on Rancho San Bernardino
are constructed in incised channels that are on average six metres deep and can
be as wide as 100 metres. Erosion control structures also include earthen berms
as wide as 900 metres, and cement spillways with reservoirs.
There
is a long record of successes and failures of erosion control structures in
networks of small gullies. DeLong and Henderson (2012) noted, however, that “we
are unaware of a comparable attempt to use gabions and berms for the sole
purpose of ecological restoration along >10 km of arroyo channels draining
watersheds on the order of ~400 km2 and larger.”
Research
to develop detailed topographic surveys using terrestrial and airborne laser
detection and remote sensing, coupled with hydrological modeling, field
observation, and stream-flow sensors is providing data on the impacts of
restoration efforts on sediment and hydrology (Delong & Henderson, 2012;
Henderson & DeLong, 2012; Jemison et al., 2012).
Remote
sensing monitoring by the U.S. Geological Survey of Rancho San Bernardino shows
vegetation growth around gabions and berms despite documented drought. Comparing
gabions used for urban flood control in the Mexican border city of Nogales with
those at San Bernardino, researchers with the U.S. Geological Survey and the
University of Arizona posited that the success or failure of gabion structures
is closely related to the goals of installation, noting that the gabion dams on
Rancho San Bernardino were constructed for riparian restoration not flood
control (Gass et al., 2013). USGS members observed that a
combination of restorative practices “has successfully restored ecosystem
function to riparian corridors in this once lost, but not forgotten cieñega wetlands”
(L. Norman, personal communication, March 2014).
DeLong
and Henderson (2012) concluded that the interactions between engineering,
sedimentation, flood hydrology, and vegetation growth contribute to the
resilience of the erosion control techniques at Rancho San Bernardino, working
together to prevent a serious failure of the gabion dams. DeLong, who has been
monitoring erosion control at the San Bernardino Ranch since 2007, observed
that “some of these techniques can be more broadly applied to stabilize
subsurface and surface water resources throughout other dry regions”.
DeLong and Henderson (2012) suggested that the continuing quantification of
restoration efforts at San Bernardino “may prove useful in guiding similar
large-scale ecological restoration efforts in degraded dryland landscapes.”
Despite
the drought — including the declining winter precipitation in the Chiricahua
Mountains — water is returning to this degraded landscape (Broska, 2009). In
large part, the reduction of the erosive scouring of the landscape during
extreme rain events during the monsoon seasons is increasing the availability
of seasonal and permanent water (Radke, 2013). When hosting a delegation of
some twenty visiting ranchers from neighboring Chihuahua at the San Bernardino
Ranch on October 12, 2013, Valer Austin explained that the end objective of the
gabions and trincheras was not to collect surface water but
rather to restore a landscape that absorbs rather than sheds water — “to
function like a sponge” (V. Austin, personal communication).
Among
the signature achievements of CLO and the Rancho San Bernardino restoration
project is the recolonizing of the upstream and downstream wetlands with native
fish without the need for active reintroduction projects (Radke, 2013). Surveys
during 2008-2011 documented the presence of six of the eight Río Yaqui native
fishes in the San Bernardino Creek, pointing to the success of CLO’s
restoration work in slowing erosion, raising groundwater levels, and giving
rise to dense stands of cattail and bulrush along the once barren creek (C.O.
Minckley, 2013).
Researchers from the Universidad de Sonora have documented the
increasing biodiversity on Rancho San Bernardino as part of a plan to have the
ranch designated as a privately owned wildlife reserve. The researchers
concluded that the “huge change” at the ranch — which has a “history of
agriculture and livestock exploitation beyond the capacity of recovery” — in
the retention of sediment and water has resulted in the attraction of many
diverse species of mammals and birds. Monitoring over short periods documented
the presence of 85 bird species (Cárdenas-García & Olguín-Villa, 2013) and
26 species of mammals (Bonillas-Monge & Valdez-Coronel, 2013).
The
impact of livestock on the aridlands of this transborder region is a subject of
debate amongst environmentalists, government agencies, and the ranching
community. To a large degree, this debate is about differing philosophies and
priorities. Environmentalists who prioritise biodiversity and the restoration
of natural habitats generally oppose grazing cattle on public lands and in
stressed ecosystems (Brown & McDonald, 1995). Others, including sectors of
the environmentalist community, argue that livestock can play a critical role
in maintaining and restoring healthy desert grasslands, especially when
ranchers adopt holistic range management techniques (Schwartz, 2013). The
“Working Wilderness” slogan of the Malpai Borderlands Group (Sayre, 2005) is
emblematic of a highly contested land-management philosophy positing that
healthy open landscapes depend on livestock grazing by spreading seed, making
soil more permeable to water, and keeping grasses trimmed and growing.
Recent
research about land conditions subsequent to cattle removal in sections of the
San Bernardino Valley helps inform this discussion (R.L. Minckley, 2013). For
the past three centuries, livestock have been a constant feature on this arid
and semi-arid landscape. The removal of cattle by USFWS in the early 1980s in
the newly created San Bernardino refuge and across the border by CLO in 1999
presented Robert Minckley with the opportunity to study the impact of cattle on
the spectrum — riparian, grassland, and desert shrub — of desert habitats in
the San Bernardino Valley. As might be expected, the comparative survey found
that vegetation responds rapidly to reduced grazing or no grazing in areas with
surface water, leading to habitats “with great vertical development not
previously found or barely present in grazed areas” (ibid.: 321).
Minckley noted that in the areas of the refuge and CLO’s Rancho San Bernardino
with water “the capture of carbon in thick tree trunks is greatly increased,
and the litterfall and carbon addition to soils and watercourses is increased
manifold” (ibid.: 321).
Speaking in Spanish to groups of Mexican preparatory students on
a 2013 field trip to Rancho San Bernardino that I witnessed (see Figure 2),
Valer Austin offered a concise narrative sweep of the region’s exploitative
history. “For the last couple of hundred years, we humans have been taking,
taking, always taking from nature,” she observed, “and now it’s our time to
start giving back.”
CLO
has increasingly insisted that sustainability strategies must extend beyond a
narrow focus on land protection. Conservation and restoration efforts should
“address the environmental, social and economic challenges of the region in a
strategic and integrated fashion” (CLO, 2008: 2) Furthermore, “The area needs
to be protected as a wildlife corridor…. [But] the border region should also be
an area of rich cultural exchange between people of two nations. Instead it has
become a zone of contention.” CLO says that it “hopes that this effort would be
seen as an alternative to the many top-down, security-driven actions being
implemented by the U.S. government on the border at great cost to local
communities, the environment, and cross-border cooperation” (ibid.: 3).
As
the land heals from overgrazing and interventionist restorative techniques, CLO
is reaching out to its Sonoran and Chihuahua neighbors with proposals to
participate in Borderlands Restoration, a CLO partner, terms “community-based
collaborative” land restoration” (Pulliam, nd). These collaborative initiatives
include a partnership with Don Cuco Sotol, which produces and markets sotol
liquor. CLO invited the family enterprise with an international market to
harvest fleshy hearts of the agave-like sotol plant in the Sierra San Luìs. In
return, the family has agreed to take measures to ensure that the natural rates
of sotol growth are maintained.
CLO
is also cultivating native grasses and experimenting with seed harvesting with
the intention of fostering a social enterprise that markets these native grass
seeds — which currently are only available from U.S. distributors. CLO, working
closely with Borderlands Restoration L3C, is also exploring plans to cultivate
and distribute desert plants that attract hummingbirds and other pollinators
such as bees, butterflies, moths, and bats — all of which have experienced
habitat loss as a result of desertification.
Another
hopeful sign that a restoration economy is emerging can be found south of
Rancho San Bernardino in the Ejido 18 de Agosto. During a November 21, 2012
visit, ejido representative Marcelino Alfaro and other
community members recounted in personal communication how the ejidatarios initially
opposed CLO’s restoration project, fearing that CLO’s restoration projects were
capturing scarce water, thus further limiting their own access to surface and
subsurface water. Today, however, the ejidatarios are erecting
their own trincheras and gabions, while reporting that the Río San
Bernardino is once again running year-round through their land and well levels
have stabilized or risen despite the record-breaking drought.
The
restoration initiatives of CLO are part of an emerging and evolving framework
of collaboration and governance involving public and private actors on both
sides of the border.
On
the U.S. side, the most influential private participants in the emerging
governance are CLO, The Nature Conservancy, Sky Island Alliance, Borderlands
Restoration, Animas Foundation, and the Malpai Borderlands Group. Many of the
ranchers associated with the Malpai Borderlands Group sign “conservation
easements” in which private foundations compensate the ranchers for the
development potential of their ranch, thus giving them an incentive to maintain
their ranching lifestyle, not sell their land, and keep the rangeland from
being subdivided (Sayre, 2005). Working closely with these private groups are
U.S. and state agencies that are major stakeholders in the region such as the
U.S. Geological Survey, Natural Resources and Conservation Service, U.S. Fish
and Wildlife Service, Bureau of Land Management, and Arizona Game and Fish
Department.
On
the Mexican side, since the late 1990s CLO has broken new ground in
establishing working agreements and forging common restoration agendas with an
impressive array of local, state, and federal agencies, including Secretariat of
Environment and Natural Resources (Semarnat) National Forest Commission,
National Ecology Institute, National Commission for Protected Areas, among
others, and winning Mexican governmental and university awards in the process.
With respect to advancing its vision for restoring the entire Río Yaqui and
Sierra Madre Occidental wildlife corridor, CLO also works closely with the
Mexican NGOs Pro-Natura and Naturalia, both of which have established nature
refuges along the western flanks of the Sierra Madre Occidental in Sonora.
Ranchers from the region now visit Rancho San Bernardino to learn about CLO’s
erosion control and grassland restoration projects and methodologies.
Chihuahua ranchers standing on gabions at
Rancho San Bernardino see how this type of erosion control is filling in
incised arroyo with sediment and contributing to revegetation of formerly
barren channel
As
CLO is drawing increased national and international attention because of its
cutting-edge on the San Bernardino ranch, discussion is turning to the many
unanswered questions about drylands restoration and to the challenges of
maintaining and expanding CLO’s work.
Two
unanswered questions raised by the Rancho San Bernardino experiment are: What
is the relationship between increased surface water on the ranch and
groundwater levels, and by extension to the regeneration of the desert
grasslands? Can restorative techniques endurably replace deeply rooted woody
desert shrubs with native grasses, and would such a project pass a cost-benefit
evaluation?
There
are also pressing questions about cattle and the restoration of aridlands. If
the principal goal of large-scale restoration of desert landscapes is to
restore entire ecosystems and associated wildlife corridors, what role, if any,
do livestock have in contributing to this goal? A more practical question faced
by ranchers and land managers is whether the livestock industry is economically
sustainable as surface and subsurface water diminishes, droughts persist, and
temperatures rise.
Although
the impressive results at Rancho San Bernardino (and on other CLO properties)
have made it a model of large-scale restoration of arid and semi-arid
landscapes, there are many challenges in sustaining this model, growing it, and
replicating it in other regions. These challenges largely revolve around
questions about political will, institutional frameworks, and finances.
For
the most part, the successes (and shortcomings) of the experiment are almost
wholly dependent on the vision, determination, and economic resources of the
CLO principals. Can governmental and nongovernmental entities overcome the
border divide and create cross-border frameworks and funding mechanisms for
maintaining CLO restoration projects well into the future? Can Rancho San
Bernardino serve as a pilot project for an ecoregion-wide restoration strategy
with diverse biodiversity, carbon sequestration, and sustainable economy goals?
If so, what would be the governance frameworks and funding sources for this
transborder land restoration? Can transborder collaboration on land restoration
and on building restoration economies supplant border security as a more
constructive borderlands paradigm?
Most
casual observers of degraded arid and semi-arid landscapes in the southwestern
United States and northwestern Mexico dismiss these drylands as “badlands” or
wastelands with little ecological or economic worth. A visit to the San
Bernardino Valley — and especially to the land restoration projects of CLO and
the neighboring USFWS refuges – would surely alter that impression. Monitoring
of these projects by scores of scientists and scholars is also creating a new
body of knowledge and literature on drylands restoration that will prove
valuable to other large-scale drylands restoration projects around the globe.