Pleistocene Rewilding
Pleistocene rewilding , or just rewilding , is a term that is mainly used in English and describes the renaturation of natural areas by means of the reintroduction of the megafauna that was formerly represented in the respective region .
This is based on the assumption that species that have been exterminated by humans or displaced from the wild, especially large animals, make an important contribution to the functionality of their ecosystem and that their reintroduction is therefore essential for authentic dynamics in the respective areas. This is known as the megaherbivore hypothesis . The argumentative legitimation of the reintroduction of locally extinct species in the Pleistocene or their replacement is partly dependent on the application of the overkill hypothesis , which sees humans as the main cause of the Pleistocene extinction wave.
background
Today's land vertebrate - Fauna was created under the influence of a once on almost all continents -present megafauna, the big game. Not only were predators and prey dynamic to one another, but also large herbivores related to the types of landscape they shaped or influenced according to the mega- herbivore hypothesis. If the overkill hypothesis applies in general, the elimination of the megafauna and the resulting ecological changes would be an unnatural condition that threatens the already reduced biodiversity . The reintroduction or partial replacement of the megafauna would have the following advantages, according to proponents of rewilding:
- Practical testing of the mega herbivore hypothesis. So far it is unclear whether grazing by large herbivores can keep areas open in the long term or open forests .
- Species protection : The reintroduction of potentially threatened species into areas where they once died out or were exterminated has always been a goal of species protection.
- Natural dynamics of fauna and flora. Small and medium-sized animals are directly or indirectly dependent on the megafauna. Large herbivores, for example, are the prey for predatory species such as wolves or northern lynx that sporadically invade Europe , which have so far caused problems by cracking livestock . Conversely, the population of megaherbivores is regulated by large predators. That their introduction is necessary for this is shown by the fact that it is currently necessary in some North American national parks , such as Yellowstone National Park , to kill excess animals. Birds such as cattle egrets and lapwing benefit from megaherbivores on the one hand because they scare away insects, which subsequently devour the cattle egrets that reside nearby, or by keeping open areas that function as nesting sites. The excrement of large herbivores contributes as a natural fertilizer to the nutrification of pasture areas. Furthermore, megaherbivores participate in the spread of seeds through the consumption of fruits . An example of this is the milk orange tree , the fruits of which may have been dependent on being opened by the megafauna that originally lived there.
- Tourist advantage for structurally weak regions that border on such wilderness areas, analogous to the Kruger National Park .
Since at the end of the Pleistocene and in the course of the Holocene there was not only local extinction , but also a number of species became globally extinct or extinct, some populations cannot be replaced by representatives of the same species. In these cases, there is the possibility of replacing them with ecologically and morphologically similar relatives. For example, some time ago , large emus were released into the wild on Kangaroo Island instead of the exterminated kangaroo island emus . In the case of wild animals that were once domesticated , one can fall back on suitable domesticated descendants. One possibility is to reintroduce a suitable breed into the wild , for example the Konik or the Exmoor horse are proposed as a replacement for the European wild horse , of which the former can be found in the Oostvaardersplassen , the latter in the Exmoor National Park . Furthermore, some breeds were bred with the stipulation that they approximate their wild form ( breeding of images ). Another possibility is to use breeds of domestic animals that have already become wild animals again through de- domestication , such as mustangs .
criticism
It is noted that 10,000 years is a sufficient time span for a new climax society to emerge between the remaining species in terrestrial ecosystems . Some also refer to the ability of large herbivores to keep parklands open or to open up forests, i. H. on the mega herbivore hypothesis, doubted ( see main article ). It is countered, among other things, that through the millennia of reduced large animal diversity, norms developed which consider this condition to be natural.
Rewilding Initiatives
The first example of a large mammal that became extinct on one continent at the end of the Pleistocene was reintroduced from another region was the case of the mustangs. They are by no means neozoa , but with Equus ferus they belong to a species that existed in North America before the arrival of humans. However, they are feral domestic horses , not real wild horses . The threatened yellow-tipped gopher tortoise was reintroduced to New Mexico by the Turner Endangered Species Fund , which occurred in North America during the Pleistocene. Donlan et al. postulate that a Pleistocene rewilding project could be started with these species, which could eventually end with Holarctic lions .
During the last Ice Age, musk oxen were spread over a large part of Eurasia and North America, which at that time were shaped by tundras . However, during the late Pleistocene and Holocene, their numbers dwindled until they were limited to northern Canada and Greenland only. However, they have been successfully reintroduced in regions of Norway , Sweden , Siberia, and Alaska (where they were only eradicated in the 20th century ).
The Pleistocene Park is a project that aims to re-emerge the mammoth steppe by reintroducing large tundra dwellers . Yakuten horses , bison and musk ox were introduced to a reserve in the south of Sacha , which joined the existing wild stocks of snow sheep , Altai Maral and elk .
In 1992 red deer , Koniks and Heck cattle were released to the wild in order to prevent the Oostvaardersplassen nature development area from becoming overgrown. These now form large herds and number around 2200 animals in total. The high numbers of animals without regulation by predators lead to starvation in many animals in winter.
Rewilding Europe is an organization that aims to reintroduce large European game as far as possible on a hoped-for area of around one million hectares . Five core areas were defined: Western Iberia , the Eastern Carpathians , the Danube Delta, the Southern Carpathians and Velebit in Croatia. Rewilding Europe collaborates with other Taurus Project , a multidisciplinary project that one of the aurochs strives to come as close as possible to end cattle line. The founding and crossing animals of the project are already alive. a. free in the Keent nature reserve .
See also
Web links
Individual evidence
- ^ Megafauna: First victims of the Human-Caused Extinction
- ^ M. Galetti: Parks of the Pleistocene: Recreating the cerrado and the Pantanal with megafauna . In: Natureza e Conservação . 2, No. 1, 2004, pp. 93-100.
- ↑ a b c d C.J. Donlan, et al .: Pleistocene Rewilding: An Optimistic Agenda for Twenty-First Century Conservation . In: The American Naturalist . 2006, pp. 1–22.
- ↑ CI Donatti, M. Galetti, MA Pizo, PR Guimarães Jr., and P. Jordano: Living in the land of ghosts: Fruit traits and the importance of large mammals as seed dispersers in the Pantanal, Brazil . In: R. Green, EW Schupp, and D. Wescott (Ed.): A. Dennis (Ed.): Frugivory and seed dispersal: theory and applications in a changing world . Commonwealth Agricultural Bureau International, Wallingford, UK 2007, pp. 104-123.
- ↑ a b Bunzel-Drüke, Finck, Kämmer, Luick, Reisinger, Riecken, Riedl, Scharf & Zimball: Wilde Weiden: Practical guidelines for year-round grazing in nature conservation and landscape development
- ↑ Tim Flannery (2001): The Eternal Frontier: An Ecological History of North America and its Peoples , ISBN 1-876485-72-8 , pp. 344--346
- ↑ Bunzel-Drüke, Drüke & Vierhaus: Reflections on the forest, people and megafauna .
- ↑ Connie Barlow and Paul Martin, 2002. The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms , which covers the now-extinct large herbivores which fruits like the Osage-orange and Avocado co-evolved with in the Western Hemisphere .
- ↑ Konik horse - Equus ferus f. caballus - Large Herbivore Network
- ↑ Wildlife Extra News on the Exmoor horse
- ^ Rubenstein et al .: Pleistocene Park: Does re-wilding North America represent sound conservation for the 21st century? 2006.
- ↑ Cis van Vuure: Retracing the aurochs - History, Morphology and Ecology of an extinct wild ox. 2005, ISBN 954-642-235-5 .
- ^ Franz Vera: Large-Scale Nature Development - the Oostvaardersplassen .
- ↑ Kirkpatrick & Fazio: Wild Horses as Native American Wildlife . 2005.
- ^ Official website of the Pleistocene Park
- ^ Rewilding Europe: United for the conservation of Europe's large carnivores
- ^ Official website of Rewilding Europe
- ↑ Auroch's Project aims to breed back extinct cattle
- ^ Brabants Landschap: Het Taurus-rund op Keent. 2010.