by Michael Soulé
Fifty years ago, the earth's human population was half of today's six billion. Large tracts of roadless tropical and temperate forests and savannas still survived, as did unspoiled coastlines and estuaries, unexploited fisheries and healthy populations of gorillas, rhinos, lemurs, sea turtles and frogs. Now, the explosion of our numbers, commercial globalization and the invention of new technologies for land clearing, agriculture and fishing have changed all this, with dire consequences for nature and wildlife.
In the more productive and biologically rich parts of the planet, development has cleaved nature into isolated remnants – forest reserves, national parks or remaining but vulnerable wildlands. But most of these fragments are degraded, overhunted and laced with roads that accelerate further exploitation and destruction. The rarest animals are among the first to disappear in these island-like fragments. Some of these species, such as jaguars or wolves, are critical ecological actors, or what are called keystone species. Where keystone carnivores disappear, entire ecosystems can collapse. Those species that survive this collapse may not persist for long if their populations are small. Small populations are vulnerable to random events like hurricanes, droughts and inbreeding. Over time, more and more species disappear, until there is little left but a lonely silence.
Fortunately, conservation biologists know how to arrest and even reverse this kind of ecological disintegration. First, restore the severed connections between the isolated bits of nature at both local and continental scales; second, repatriate the keystone species; third, enlarge and rehabilitate the most pristine areas so that they contain all of the original habitats, including free-flowing rivers, unpolluted lakes and the full range of species interactions. All this is what we call "rewilding." Fourth, control the most damaging exotic species. Simple, but not easy. Is such a bold, ambitious project realistic at a continental scale?
In 1991, a group of activists and scientists founded the Wildlands Project. The goal was to link up wildlands from Mexico to the Yukon, from Florida to Newfoundland, from Baja California to the Brooks Range and the Bering Sea. Connections to the North Woods, the Great Plains and great northern boreal forest would also be re-created.
People called the vision "delusional," a hallucination of romantics. Ten years later, however, the basic concepts are mainstream. The idea of rewilding continents, by restoring the keystone species and healing other wounds to our lands and waters, has been widely adopted by the conservation community because it is the only realistic prescription for preserving entire faunas and floras. Internationally, partners such as The Wilderness Society (of Australia) are adapting the vision to other continents.
The volume Continental Conservation: Scientific Foundations of Regional Reserve Networks (1999, Island Press) sped the adoption of the rewilding vision by summarizing the critical role of keystone species and arguing for the restoration of landscape linkages that had been severed by poor land-use practices.