What Is Restoration?
by BR founder, Ron Pulliam
There are two common definitions of restoration. One is the ‘return of something to its former or normal state’ and the other is an ‘act of renewal, revival, or reinvigoration’. Some people have applied the first definition to habitat restoration and have argued that we should restore the species composition to some primordial or, in America, to a “pre-Columbian” state. This would mean somehow figuring out exactly what used to be here and then striving to reestablish that particular mix of species. The problem with this approach is that ‘what used to be here’ may not be what is adapted to live here either now or in the future.
When it comes to habitat restoration, I prefer the second definition. I believe that we restore ecosystems by enhancing their ability to change as their environments change. For the past few years, I have been collaborating with Valer and Josiah Austin on restoration projects on their ranches in Arizona and Sonora. The Austins, and the Cuenca los Ojos (CLO) foundation that they founded, have restored several large watersheds by building thousands of berms and rock dams (gabions) to slow the water down and allow greater infiltration of water into the soil. The results are astounding. Rather than flash floods that roar through deeply eroded stream beds in a day or two, streams now flow year around. For example, on the San Bernardino Ranch, east of Agua Prieta, ten years after intensive restoration work began, a 3-mile stretch of the San Bernardino River has returned to perennial flow for the first time in 100 years.
When water returns to an arid ecosystem, life returns. The cienega on the San Bernardino Ranch was once one of the largest and most productive wetlands along the US-Mexico border. Early in the last century, the wetlands were completely drained, and beets and other crops were grown until the soil was no longer productive. Today, following restoration, what were badly eroded washes and dried-out cienegas are once again verdant riparian forests and wetlands. When the Austins purchased the ranch, 97% of the original cienega was gone, but a recent study has shown that in the past ten years, the cienega has grown from 3% of its original extent to over 20%.
As the water and vegetation have recovered, animals like bobcat, black bear, coati mundi, raccoon, and skunks are slowly returning as well. But the recovery of animal populations is far from complete, and recent studies have suggested that the recovery of many species, like hummingbirds, nectar-feeding bats, tanagers, and orioles, is slowed by a lack of appropriate food plants. As a result, thousands of native nectar- and fruit-producing plants are being planted and before and after surveys are being conducted to monitor the animal population responses.
Much of what has been learned from the restoration work conducted at San Bernardino and other CLO ranches can be applied elsewhere in the borderlands region. Based on the restoration experience on the CLO ranches, we have identified what we call the ‘three pillars’ of habitat restoration in arid lands. These are 1) restore physical processes, like stream flow and ground water recharge; 2) restore food plants, especially nectar and fruit producing plants, that form the base of the food chain; 3) restore the link between people and wildlife by involving local citizens in restoration work.
The goal of the Borderland Habitat Restoration Initiative is to restore the linkages among wildlife, land, and people. As impressive as the restoration work is on the CLO ranches, we realize that to have a real impact on wildlife we must restore far more land and work at a regional scale. If one family can restore thousands of acres, think what large numbers of volunteers working throughout the borderlands region on both sides of the border can accomplish. In addition to accomplishing more wildlife habitat restoration, engaging local citizens builds bonds between people, land, and wildlife and helps to ensure a committed community of people who understand the importance of wildlife and land stewardship and who take responsibility for ensuring that the restored lands and wildlife populations will persist for future generations to enjoy.
H. Ronald Pulliam is a retired Regents Professor from the Odum School of Ecology at the University of Georgia. He has published over 100 scientific articles and books and served as President of the Ecological Society of America, as Director of the National Biological Service, and on the boards of numerous scientific and environmental organizations.