About the Region
The Madrean Archipelago is one of the most biologically diverse areas of the world (Koprowski, 2005; Skroch, 2008). Approximately 40,536 km2, this region extends from southeastern Arizona and southwestern New Mexico to northern Sonora and Chihuahua. Here the Rocky Mountains from the north meet the Sierra Madre from the south and the Chihuahuan Desert from the East joins the Sonoran Desert from the west. The dramatic convergence of these geographic regions forms the foundation for ecological interactions found nowhere else (Skroch, 2008).
The upper elevations of the ranges (from 2,500-3500m+) rise above the valley floor (600m) as veritable islands, separated by the barrier of the biotic zones in the lower elevations. Habitat-determinant factors such as temperature range and annual rainfall, vary extensively with the topography and create 8 distinct life zones (Skroch, 2008).
At the high reaches, the "sky islands" support a canopy of ponderosa pine, Douglas fir, and Englemann spruce. Going down slope from mountain crests, the evergreen forest gives way to woodlands of oak and juniper, which in turn meet the desert shrub and semi-arid grasslands of the valley floor. The terrain supports an extraordinary variety of animal species, both native and migratory. This is a key stopping point for birds that travel along the North American flyway and is the home of the northern Jaguar. There are a number of species that are threatened or in danger of extinction, the Grizzly bear and the Mexican grey wolf, for example, were exterpated from the region (see Wildlife Protection & Reintroduction for more on this).
In normal years, the region receives its life-blood of water from both winter fains and from the summer monsoons. The elevation gradient plays a factor in where the rain falls. This coupled with the convergence of the 4 significant biotic/geographic regions contributes to the high biodiversity in the Madrean Archipelago region (Coblentz, 2005).
One of the gems of the region was the San Bernardino Cienega (or wetland). This vast oasis extends seven miles north of the border into Arizona and 20 miles south into the Mexican state of Sonora. It provides rich habitat for aquatic, avian, and terrestrial species alike. In addition, there are several creeks that cross the Madrean Archipelago. Silver Creek and San Bernardino River have their headwaters in the Chiricahua and Peloncillo Mountains in southeastern Arizona and southwestern New Mexico. Silver Creek is mostly ephemeral, but thanks to CLO’Äôs restoration work, has sections that are now perennial. The San Bernardino River is perennial and provides vital habitat particularly for migratory waterfowl. Guadalupe Creek is an ephemeral stream that comes out of New Mexico and drains into the San Bernardino River. The Cajon Bonito is a deep permanent water source that flows out of the Sierra Madres and after winding north and westward ultimately connects with the San Bernardino, the Bavispe and ultimately into the Rio Yaqui.
Historically, this region was used for ranching and farming. Large cattle operations ran livestock on the plains and up into the foothills. Land on the valley floor was irrigated with water from the Cienega and used to cultivate potatoes, peppers, and alfalfa. Unfortunately, the cienega became overtapped and ultimately began to dry up (a process exacerbated by erosion and down cutting of the adjacent streams) and the once rich verdant wetland became a dusty, eroded shadow of itself. By the 1970s, the farming had ceased and now only scanty livestock operations remain. Much of CLO's work is focused on restoring this important wetland.
The US-Mexico border cuts across the northern section of the Madrean Archipelago. Historically this geopolitical boundary had little effect on wildlife. However, the recent construction of the international border fence and the accompanying road has significantly affected the ecological unity of the region. The once open basin where wildlife could pass through livestock fences is now bisected with a more solid structure that is forbidding to larger wildlife such as deer and pronghorn. The road that runs the length of the fence creates a barrier to smaller animals because it removed the cover they need to cross. Furthermore, the road creates a fire break that prevents the natural path of fire, which is a necessary part the health of this semi-arid grassland system.
In some remote sections of the border, the federal agencies listened to concerns from conservation groups and installed "Normandy" style vehicle barriers that at first was thought to accommodate wildlife movement better. The cross beam construction does allow the passage of medium sized mammals such as fox and bobcats, but the structure has been discovered to be confusing to deer whose vision makes it impossible to navigate through or over.
One of the primary trans-state roadways, Route 2, runs east-west crossing Sonora. Currently it is a narrow, 2-lane road but plans are underway to expand it into a 4-lane highway. Approximately 50 km of the proposed expansion stretch go through lands owned and managed by CLO. Clearly any significant change in the road stands to have a large impact on the environment and will directly affect the land protection and restoration work that CLO has been doing for the last 20 years. CLO is committed to working with the Mexican government to ensure that any changes in the road will take into account the nature of the surrounding environment and the fact that it is federally protected by CONANP. CLO is working to narrow the footprint and to have wildlife passages incorporated into the construction design.
Thanks to Cuenca los Ojos and many of its partners on both sides of the border, such as the Animas Foundation, the Malpai Borderlands Group, the Nature Conservancy, the Sky Islands Alliance, Wildlands Network, Naturalia, Pronatura, and the Northern Jaguar Project, this area is now valued as a wildlife sanctuary and the importance of preserving this area as a wildlife corridor is recognized.
Today a window of opportunity has opened up to protect these lands. As traditional ranching becomes increasingly unprofitable, we look for a new land use. The hope is that this use will be a protected corridor for wildlife. CLO is committed to working with private landowners and organizations, who either own or manage land along the border to come together to coordinate efforts to protect open space and restore degraded lands. In addition, CLO is dedicated to working with the Mexican Government to ensure the protection of this region and to restore it to its natural richness.