What is rewilding?
Rewilding, or re-wilding, activities are conservation efforts aimed at restoring and protecting natural processes and wilderness areas. This may include providing connectivity between such areas, and protecting or reintroducing apex predators and keystone species.
Rewilding is a form of ecological restoration with an emphasis on humans stepping back and leaving an area to nature, as opposed to more active forms of natural resource management. Rewilding efforts can aim to create ecosystems requiring passive management. Successful long term rewilding projects can need little ongoing human attention, as successful reintroduction of keystone species creates a self-regulatory and self-sustaining stable ecosystem, possibly with near pre-human levels of biodiversity.
While rewilding initiatives can be controversial, the United Nations have listed rewilding as one of several methods needed to achieve massive scale restoration of natural ecosystems, which they say must be accomplished by 2030.
Elements required for successful rewilding
Rewilding aims to restore three key ecological processes: trophic complexity, dispersal, and stochastic disturbances. Rewilding is important on land but perhaps more important is where land meets the water. Dam removal is the first of many steps in the process of rewilding in the riverine ecosystems. However, there are problems that should be addressed before, during, and after the dam removal. The problems are the sediments that have built up and wash out filling in spawning beds should be controlled and directed, then eliminating any and all clear cutting of trees near river banks as it raises the temperature of the water, and stopping industrial discharges.
At 90 different dam sites it has been confirmed that after a dam is built the ecosystem does rebound. However, the trend will eventually slow, stop and in some cases decline. This is often due to anthropogenic chemical, light, and noise pollution as the large bodies of water draw human activity and recreation. Nemecek writes that, “researchers found that the number of species within any given area dropped by 50%. Lastly, food sources for native animals and fish need to be introduced so as to improve the long-term sustainability of native species and curtail and/or eliminate the introduction of invasive species.
Extinction of megafauna and ecosystem degradation
“Since the worldwide expansion of modern humans (Homo sapiens) began, humans have overexploited vertebrates, with a bias to the largest animals being extirpated first, from the Late Pleistocene extinctions of terrestrial megafauna to the ongoing declines of terrestrial, marine and freshwater large-bodied animals. There is increasing evidence that this global wildlife loss, or defaunation, does not only imply the loss of charismatic animals but also the functions they have in ecosystems”.
Both grassroots groups and major international conservation organizations have incorporated rewilding into projects to protect and restore large-scale core wilderness areas, corridors (or connectivity) between them, and apex predators, carnivores, or keystone species (species which interact strongly with the environment, such as elephant and beaver).
Projects include the Yellowstone to Yukon Conservation Initiative in North America (also known as Y2Y) and the European Green Belt, built along the former Iron Curtain, transboundary projects, including those in southern Africa funded by the Peace Parks Foundation, community-conservation projects, such as the wildlife conservancies of Namibia and Kenya, and projects organized around ecological restoration, including Gondwana Link, regrowing native bush in a hotspot of endemism in southwest Australia, and the Area de Conservacion Guanacaste, restoring dry tropical forest and rainforest in Costa Rica.
Rewilding is the most exciting and promising conservation strategy to slow down or halt the 6th mass extinction of species. It also has tremendous potential for climate change mitigation and has had documented successes in restoring biodiversity and ecosystem processes. It however needs to be applied with a clear vision of the history of an area and what can be restored.