October 19, 2023
In the new book Mexico’s Valleys of Cuicatlán and Tehuacán, authors David Yetman and Alberto Búrquez provide an accessible and photographic view of the culture, history, and environment of an extraordinary region of southern Mexico. The Valleys of Cuicatlán and Tehuacán are lauded by botanists for their spectacular plant life—they contain the densest columnar cacti forests in the world. Recent archaeological excavations reveal them also to be a formative Mesoamerican site as well. So singular is this region that it is home to the Tehuacán-Cuicatlán Biosphere Reserve and a UNESCO World Heritage Site. The authors have been traveling to the area for two decades. Today, David Yetman answers a few questions about their newest collaboration:
What inspired you to collaborate on this work?
Alberto and I gained familiarity with Sonora via different routes, he as a Sonoran-born Cambridge-trained ecologist, I as a wandering desert rat trained in philosohy. We met at a field research school in Alamos, Sonora, sponsored by Tucson Audubon Society in, I believe, 1993 and immediately discovered our shared interests. We also realized rather quickly that our areas of interest complemented each other. Two years later we initiated a study of buffelgrass ecology in the small town of Tecoripa in eastern Sonora. During meeting key members of the community, we learned that representatives of the Mexican department of land reform were in the town discussing with townspeople the prospect of converting their cooperatively owned lands to private. We at once realized this was a historic moment in Sonora and spent the next year following the privatization procedures and interviewing the landowners involved. We published an article with our findings in 1997. In 2003 Alberto joined me in filming an episode of The Desert Speaks in the valleys called Cuicatlán in northern Oaxaca and Tehuacán in adjacent southern Puebla. We realized then that we had been pulled into a region with uncanny resemblance to the Sonoran Desert. We also realized that we enjoyed working together. Some twenty trips to that area later, we have published the book.
The plants in the region are so varied and so unusual that Mexico has designated it as a biosphere reserve, and UNESCO has followed, designating it a World Heritage Site. Why is the area so singular?
The valley’s peculiar location as connected desert valleys among several mountain ranges in the tropics has given rise to a bewildering variety of ecological zones or habitats, notably a desert environment where lusher vegetation would be expected. Those unusual conditions and a climate more or less stable for millions of years have combined to produce an astonishing array of desert plants, especially columnar cacti, many of which occur nowhere else. The high degree of endemism within the valleys means that it is the place to study these species and the evolutionary processes that promotes widespread speciation. At the same time, the region has seen the evolution of peoples of many different ethnicities. We long ago that discovered that they have stories to relate that complement the high diversity of the valleys.
The Valleys of Cuicatlán and Tehuacán also have a long human history. What are a few of the ways that visitors to the area today can see the continuity of human experience?
The archaeological sites within the valleys have not received the attention they merit, so visitors often must discover their location and history on their own. Alberto and I have presented four of these and their developmental history in a way that will assist visitors in locating and visiting these sites. One such site is Purrón Dam, which was the largest dam in the Americas two thousand years ago, but today not even located on maps. Another is the astonishing site of Cerro Quiotepec, located in an extraordinarily scenic hilltop far above where the two valleys converge and form a profound canyon. It is a highly developed site that was occupied for six hundred years before the Zapotec builders abandoned it in about 300 CE. At the same time the valleys’ varied resources have brought together at least eight different indigenous groups. They have established the human history of the valleys, with connections throughout Mesoamerica. Many towns in the valleys retain their indigenous identity.
What is your next project?
We have repeatedly discussed the importance of returning to Tecoripa after nearly thirty years to see what changes have occurred in the town’s social and economic structure because of the move from cooperatively owned to privately-owned land. We also have many places of ecological and social significance that we would like to visit, study, and describe. We have separate careers, but we remain close friends with a tacit agreement that soon we must find another area to visit, study, discuss, and describe. Sonora has a wealth of ecological and cultural surprises, all within a day’s drive of Tucson, less yet from Hermosillo, where Alberto lives. It is only a matter of time.
David Yetman is distinguished outreach faculty and a research social scientist at the Southwest Center of the University of Arizona, where he has worked since 1992. His research specialties include the peoples and ecology of northwest Mexico and the southwestern United States. Yetman has a PhD in philosophy and is author of numerous books and articles, including Sonora: An Intimate Geography, Natural Landmarks of Arizona, and The Saguaro Cactus: A Natural History. Yetman is the former host of the PBS series The Desert Speaks and current host and co-producer of the PBS travel/adventure series, In the Americas with David Yetman.
Alberto Búrquez works as a researcher at the Instituto de Ecología, Department of Ecology of Biodiversity, Universidad Nacional Autónoma de México. He is a co-author (with David Yetman) of The Saguaro Cactus.