Setting aside land in hotspots isn’t enough to preserve the world’s species. We must modify the way we engineer the environments of most of the Earth.
By Michael Rosenzweig
You wake up nervous, 10 minutes before your alarm even rings. It won’t be easy to finish that proposal today, but you must. If you get it right, it will reel in that lucrative new European account. If you don’t, the company might go under.
Still, you are glad to be alive. Outside, a finch’s melodic twittering somehow energizes you, and the rich piping of the oriole high in the trees brings joy. The green backdrop of your patch of the Earth reassures your subconscious that it might even be able to survive the loss of that account after all. Silently, you bless the architects and ecologists and landscape engineers for your habitat.
What is a hard-headed scientist doing indulging in such a flight of fancy? I work in the harshness of deserts, probe the world of non-linear dynamic equations, and explore multi-dimensional spaces. I was the first ecologist ever to use a computer to perform his Ph.D. research (at Penn, I am proud to say). My field experiments have always been laid out in neat geometrical patterns, their results scrupulously analyzed with arcane statistical methods. I am no poet.
Actually, the world of natural beauty that I write about is hard science. It is one of the two scenarios most likely to describe the human habitat of the 22nd century. Most of us now live in the other one—a sterile, cold world that gives us little comfort. But science now shows us that we need not settle for that. Our sense of the beautiful and our faith (whatever religion we belong to) tell us that we must reject sterility and choose nature.
Two scientific currents lead to this proclamation. First, the diversity of life on Earth is in worse danger than we thought. Second, we know what to do about it, and it does not involve giving up civilization, creature comforts, or profits.
It is universally agreed that loss of habitat is the primary threat to species; even so, its power to cause extinctions has been underappreciated. Once, conservationists estimated that most species would be safe if only we could set aside and protect about 20 percent of the land. But when I synthesized almost 200 years of data, analyses, and mathematical models about the effect of land area on species diversity (for a graduate textbook, Species Diversity in Space and Time, Cambridge University Press, 1995), I got a rude shock. In the long run, 20 percent of the land can save only 20 percent of species. And, by the rosiest of reckonings, we have protected only 10 percent of that land. That would save only 10 percent of species. The impending mass extinction would be considerably worse than we had thought, and here we were with no strategy to prevent it.
Now, you might be thinking: This is the sort of bad news I’m used to hearing from ecologists. But I have good news. The world’s species are not doomed, not if we get over the mistaken idea that the only safe species is one protected by a national park or a nature reserve. We do have another choice. We already engineer the environments of most of the Earth. If we modify the way we engineer them, then they, too, can participate in species preservation. At the same time, they can bring joy and beauty into our everyday lives. I call this strategy reconciliation ecology.
Conservationists already practice reconciliation ecology successfully all over the world. In the United States, the Department of Defense cooperates with organizations such as The Nature Conservancy to produce sustaining environments in hundreds of its training ranges. Eglin Air Force Base, near Pensacola, Florida, cares for a habitat that supports the endangered longleaf pine and red-cockaded woodpecker. Simulating the natural wildfires that civilization can no longer tolerate, they burn the underbrush regularly to keep it from choking longleaf pine seedlings. They even give the woodpeckers a head start by drilling nest holes in the young pines. DOD does so without relinquishing its primary job of using this land to train our military and test violent weapons. It even timbers the habitat at a profit. The National Wildlife Federation’s Backyard Habitat program enrolls more than 30,000 volunteer home sites in a panoply of projects that make those sites refuges for wild things without evicting their human owners. The nonprofit group Environmental Defense cooperates with the U.S. Fish & Game Service in safe-harbor programs that protect private property from the most stringent restrictions of the Endangered Species Act while improving it as a place for endangered species to thrive.
Examples abound overseas. Working for Water, sponsored by the government of Western Cape Province, brings jobs and water to water-stressed parts of South Africa while ensuring the future of its thousands of flowering shrub species. Farmers in Devonshire, England, have changed the schedule of crops that they grow, deliberately bringing survival back to the cirl bunting. In a few years, these birds have risen from a population of 114 to one of more than 700. And in southern Bohemia (now part of the Czech Republic), starting centuries ago, an extensive wetland was fashioned out of the forest to support fish farming. The land now teems with otter and wildflowers and natterjack toads living cheek by jowl with farms and villages, fishing and boating.
Reconciliation ecology yields opportunities for profit enhancement, too. South of Miami, Florida Power & Electric—a profit-making, free-market energy company—dug 80 miles of cooling canals to handle the clean but warm water emanating from its half-nuclear power plant. But their biologists ensure that these canals also provide a good habitat for the exceedingly rare American crocodile and many other species.
In what may turn out to be the most revolutionary farming experiment since the domestication of grain, Badgersett Research Farm in Minnesota is showing soy farmers how to multiply profits by converting their almost lifeless soy fields to hazel plantations. Hazels bear nuts rich in edible oil, and hazel plantations create a new habitat rich in species of animals, while helping solve the problems of pesticide pollution and fertilizer runoff. Moreover, hazels are woody; soy is not. Wood stores carbon dioxide, thus reducing the threat of global warming. Profit and environmental protection. You can see why a popular term for reconciliation ecology is win-win ecology.
I have merely touched the surface of available examples. Yet some believe reconciliation ecology to be a dream too utopian for the world’s realities. I hope they are wrong. For science is relentlessly clear about this: 400 million years of fossil data and surveys from all over the world teach us that if we do not reconcile our planet, we will lose its diversity.
Others have asked me whether I worry that emphasizing reconciliation will drain resources from struggling programs in restoration and reservation ecology. I do not. We are not playing a zero-sum game. Advances in reconciliation will surround us with a new world and raise our awareness of the value of saving the earth’s natural riches. Rewarded by the very presence of our good acts, we will see them as more than charity and we will want to extend and deepen their impact. We will value our nature reserves more, not less.
An outsized proportion of species lives entirely within the confines of 25 critical places, called hotspots. Though hotspots constitute a tiny fraction (1.4 percent) of the world’s land surface, 44 percent of all the world’s 300,000 species of higher plants live entirely in them. So do 35 percent of its birds, mammals, amphibians, and reptile species. Don’t hotspots diminish the need for reconciliation? Why not just focus on hotspots?
First, do the subtraction. Do you believe we should walk away from the prospect of losing 56 percent of the higher plant species and 65 percent of our terrestrial vertebrates?
Second, as their discoverers were quick to point out, hotspots are only snapshots of a dynamic reality. In nature, species come and species go. Climates shift and cycle. And we do not know why most hotspots are hot just now. But we can feel certain that 1.4 percent of the land cannot sustain much more than 1.4 percent of its species for very long. Perhaps twice or three times that many, but not 20 or 30 times that many.
Yes, we absolutely do need to pay special attention to hotspots. We cannot save their immense riches anywhere unless we do. But we cannot adopt hotspots as the end-all project to conserve species. That would give up on too many species in too many other areas, and it would create reserves too small to remain hotspots for long. Ultimately we will need reconciliation methods to save them.
I believe reconciliation ecology should be as voluntary as possible. Yet governments need to set the stage by being good stewards of the land they manage themselves and by enacting legislation that rewards reconciliation.
Reconciliation ecology promises a sweet revolution in our lives and in the prospects of a large fraction of earth’s diversity. It does require new thinking and sustained dedication. But it is a crucial part of a combination of strategies, including nature reserves, that will enable us to pass along the treasures of life to future generations.
Michael Rosenzweig G’66 is professor of ecology and evolutionary biology at the University of Arizona. He is founder, editor, and publisher of the journal Evolutionary Ecology Research as well as the author of Win-Win Ecology: How Earth’s Species Can Survive in the Midst of Human Enterprise (Oxford, 2003).
