What Is Rewilding? How Ecosystem Restoration Is Changing Conservation

## Beyond Preservation: A New Conservation Philosophy Traditional conservation has long focused on preservation — drawing boundaries around remaining wild areas and managing them to prevent further degradation. Rewilding takes a fundamentally different approach. Instead of managing nature, it aims to restore natural processes and then step back, allowing ecosystems to self-regulate. The term was coined in the 1990s by conservation biologists Michael Soule and Reed Noss, who argued that protected areas needed three things to be truly functional: **cores** (large protected areas), **corridors** (connections between them), and **carnivores** (top predators to regulate herbivore populations). This "3 Cs" framework has since expanded, but the core insight remains: ecosystems need their full complement of species and processes to function. Rewilding has grown from an academic concept into a global movement. Rewilding Europe operates across 10 major landscapes. Rewilding Britain has established a network of projects across the UK. In South America, Tompkins Conservation (now part of Rewilding Argentina) has created or expanded national parks covering over 600,000 hectares. ## The Yellowstone Effect: Trophic Cascades in Action The reintroduction of 41 gray wolves to Yellowstone National Park in 1995-1996 remains the most famous rewilding success story — and the most vivid demonstration of trophic cascades. Before wolves returned, Yellowstone's elk population had grown unchecked for 70 years. Elk overgrazed riverbank vegetation, preventing willows and aspens from regenerating. Stream banks eroded. Beaver populations collapsed without the willows they needed for food and dam-building. Songbird habitat disappeared. Within a decade of the wolves' return, the cascade effects were measurable: - **Elk behavior changed.** Elk avoided lingering in valleys and near streams where they were vulnerable to predation, a phenomenon ecologists call the "landscape of fear." - **Vegetation recovered.** Willows, aspens, and cottonwoods regenerated along rivers and streams, some growing five-fold in height within six years. - **Beavers returned.** With willows restored, beaver colonies expanded from one in 1995 to twelve by 2009. Their dams created ponds and wetland habitat for fish, amphibians, and waterfowl. - **Stream morphology changed.** Stabilized banks and beaver dams reduced erosion and narrowed channels, creating deeper pools and more complex aquatic habitat. - **Scavenger populations benefited.** Wolf kills provided carrion for grizzly bears, ravens, magpies, bald eagles, and wolverines — a food subsidy that rippled through the ecosystem. > The Yellowstone case demonstrated that a single species reintroduction could trigger ecosystem-wide recovery — the essence of the trophic cascade concept first described by ecologist Robert Paine in the 1960s. It is worth noting that the Yellowstone story is sometimes oversimplified. Other factors — drought cycles, bear predation on elk calves, and park management decisions — contributed to vegetation recovery. But the wolves' role in reshaping elk behavior and triggering the cascade is supported by rigorous long-term research. ## Knepp Estate: Rewilding in a Crowded Country If Yellowstone demonstrates rewilding in a vast wilderness, the **Knepp Wildland** project in West Sussex, England, proves it can work on former farmland in one of Europe's most densely populated countries. In 2001, Charlie Burrell and Isabella Tree abandoned intensive farming on their 1,400-hectare estate after decades of declining yields on heavy clay soil. Inspired by the work of Dutch ecologist Frans Vera, they introduced free-roaming herds of **Longhorn cattle, Exmoor ponies, Tamworth pigs, and fallow deer** as proxies for the wild herbivores that once shaped European landscapes. The results, documented in Isabella Tree's acclaimed book *Wilding*, have been extraordinary: - **Turtle doves** — Britain's fastest-declining bird species — now have one of their few remaining breeding populations at Knepp. - **Purple emperor butterflies** have established the UK's largest known breeding colony on the estate. - **Nightingale territories** increased from zero to over 30 within a decade. - **Peregrine falcons, ravens, and lesser spotted woodpeckers** have all returned without deliberate reintroduction. - Soil health has improved dramatically, with organic matter increasing and compaction reversing after decades of intensive plowing. Knepp generates revenue through eco-tourism (glamping, safaris, and courses), organic meat from its free-roaming herds, and environmental stewardship payments. The financial model demonstrates that rewilding can be economically viable — not just ecologically desirable. ## Ibera Wetlands: Continental-Scale Restoration In northeastern Argentina, the **Ibera Wetlands** project represents one of the most ambitious rewilding efforts in the Southern Hemisphere. Led by Tompkins Conservation and now managed by Argentina's national parks administration, the project has systematically reintroduced species extirpated from the region. **Giant anteaters** were reintroduced starting in 2007, with over 100 individuals now established. **Pampas deer** followed, then **collared peccaries** and **tapirs**. Most remarkably, **jaguars** — the apex predator of the Americas — were reintroduced to Ibera beginning in 2021 after an absence of over 70 years. The jaguar reintroduction used a careful protocol: wild-born cats from other regions were paired in large enclosures, bred, and their cubs raised with minimal human contact before release. By early 2026, at least 20 jaguars roam Ibera, with breeding confirmed in the wild — a milestone for jaguar conservation across their entire range. ## Rewilding vs. Traditional Conservation Rewilding and traditional conservation are not opposed — they are complementary approaches suited to different contexts. | Aspect | Traditional Conservation | Rewilding | |--------|------------------------|-----------| | **Goal** | Preserve existing state | Restore natural processes | | **Approach** | Active management | Passive (after initial intervention) | | **Human role** | Ongoing management | Step back after setup | | **Scale** | Can work at any scale | Most effective at landscape scale | | **Species focus** | Protect threatened species | Restore keystone species and processes | ## Criticism and Challenges Rewilding is not without controversy: - **Land use conflicts.** Reintroducing large predators raises real concerns for livestock farmers. Wolf reintroduction in France and Germany has generated intense political opposition from farming communities. Compensation schemes exist but are often seen as inadequate. - **Ecological uncertainty.** Ecosystems may not return to historical baselines, especially in a changing climate. Novel ecosystems — with new species assemblages — may be the realistic outcome. - **Social justice.** In developing countries, rewilding proposals can conflict with indigenous land rights and local livelihoods. The "fortress conservation" model — excluding people from protected areas — has a painful colonial history that rewilding advocates must reckon with. - **Cherry-picking success stories.** Critics argue that rewilding advocates overemphasize dramatic successes while underreporting failures and unintended consequences. ## The Scale of the Opportunity Despite challenges, the scientific case for rewilding continues to strengthen. A 2024 study in *Nature Ecology & Evolution* found that rewilding just 5% of the world's most ecologically degraded land could prevent 70% of projected species extinctions while sequestering significant amounts of carbon. The economic argument is also compelling. The World Economic Forum estimates that nature-positive investments — including rewilding — could generate **$10.1 trillion in annual business value** and create 395 million jobs by 2030. Rewilded landscapes provide ecosystem services — flood protection, water purification, carbon sequestration, pollination — that conventional land use does not. Rewilding is not a return to some imagined Eden. It is a pragmatic, evidence-based approach to restoring the ecological processes that human activity has disrupted. Where it is done well — with community engagement, scientific rigor, and realistic expectations — it is producing results that would have seemed impossible a generation ago.