Title: Will ecosystems be restored through the introduction of species to their habitats
Sources: Conservationists are reintroducing large animals to areas they once roamed, providing ecologists with the chance to assess whether such “rewilding” efforts can restore lost ecosystems. – “The Scientist” https://www.the-scientist.com/?articles.view/articleNo/39799/title/Where-
the-Wild-Things-Were/; J. Donlan et al., “Re-wilding North America,” Nature, 436:913-14, 2005.; T. Caro, “The Pleistocene re-wilding gambit,” Trends Ecol Evol, 22:281-83, 2007.; W.J. Ripple, R.L Beschta, “Trophic cascades in Yellowstone: The first 15 years after wolf reintroduction,” Biol Conser, 145:205-13, 2012.; F.W.M. Vera, “Grazing Ecology and Forest History,” CABI Publishing, 2000.; C.J. Sandom et al., “High herbivore density associated with vegetation diversity in interglacial ecosystems,” PNAS, doi:10.1073/pnas.1311014111, 2014.; C.J. Griffiths et al., “Resurrecting extinct interactions with extant substitutes,” Curr Biol, 21:762-65, 2011.; C.J. Griffiths et al., “Assessing the potential to restore historic grazing ecosystems with tortoise ecological replacements,” Conserv Biol, 27:690-700, 2013.; L.M. Navarro, H.M. Pereira, “Rewilding abandoned landscapes in Europe,” Ecosystems, 15:900-12, 2012.
Main Point: Managers and conservationist introduced Retuerta horses and Sayaguesa cattle into the Campanarios de Azaba Reserve located to the north of Spain as part of an open-air experiment that tests how successful rewilding is in this ecosystem. They are hoping that the introduction of both these species, who bare close genetic resemblance to the large herbivores that once roamed this area, will help sustain a health ecosystem and in turn, boost a greater biodiversity. While this experiment has not had long enough to provide any official evidence that these species improve the ecosystem, many other examples, like the reintroduction of wolves to the Yellowstone National Park, have provided evidence that this is a sustainable way of restoring habitats and ecosystems.
Scientific Caveats: Much of the biodiversity that was lost in these areas of ecosystem collapse happened during the Late Pleistocene, about 13,000 years ago, because of the introduction of humans that began killing these megafauna, like mammoths and mastodons, at rates higher than they could reproduce. Introducing species that are the closest living relative to these extinct species has, so far, been a success in places like the Oostvaardersplassen (located near Amsterdam) where Konik horses and Heck cattle roam in place of tarpans and aurochs. However, it is a possibility that the introduction of these species can be detrimental to the ecosystem in that these “closest living relatives” could have no resemblance to extinct species in grazing patterns, reproduction efforts, or interaction with existing species. Also, many of these ecosystems are less complex because they lack an apex predator or any large carnivores that create a more complex ecosystem. Therefore, these small scale studies are only a glimpse at the possibilities of rewilding and are used as a basis for future open-air experiments.
Relevance to Conservation Biology: Rewilding has, in many places, successfully created more biodiversity where ecosystems were failing at the hands of increased human populations and the human negligence of the natural world. This is at the core of what conservation biology is about; protecting the world’s biological diversity, restoring biological communities and investigating how humans have impacted ecosystems. Also, many of the rewilding initiatives are back-breeding species in order to “bring back” extinct species that were once a part of the ecosystem. This relates back to maintaining genetic diversity and in a way “protecting” species from extinction. While many are already extinct, using ecological evidence and genetic information, these “new” species can help bring back the biodiversity that was lost.