Bernat Garrigós
Patron and president of the Alive Foundation
Biologist & naturalist
A paradigm shift is taking place in the world of ecology and conservation that is significant enough to devote a long article to it, but if you want to learn more about it, I recommend you read the book “Rewilding, The radical new science of ecological recovery” by authors Paul Jepson & Cain Blythe.
The English version has a very plain language within the reach of a non-technical public, but you will also find the book in its Spanish version if it should be easier for you, ” Rewilding: La nueva ciencia radical de la recuperación ecológica” .
Renaturalization (rewilding in English) is a fairly recent trend in nature conservation that is gaining strength in Europe, which pioneered it, but which is also beginning to spread to other parts of the world. Renaturalization is based on a new scientific body of terrestrial ecology that we have known since the turn of the century.
Basically, the new discoveries in ecology start from a better knowledge of the paleoecology or ecology of the past which is making us see that some of the current concepts of ecology are not quite as we thought until a few years ago.
Ecology of the past
In the past, the fauna of all continents was characterized by the presence of mega-herbivores that had the role of engineers of the ecosystems, as they profoundly altered them. The disappearance of the dinosaurs left a world empty of large animals, and the subsequent millions of years of warm and humid climate saw forests spread thickly across much of the land. The large groups of herbivores, proboscideans (mastodons, elephants and mammoths), ruminants (deer, giraffes, cows and sheep) and hypsodonts (horses and donkeys) formed in this forested environment.
From smaller predecessors they evolved into larger forms and their impact on the ecosystem was spectacular. We now know that over the last 30 million years the great forests were opened up by the action of this megafauna and more open habitats of woodlands, savannahs, grasslands and other combinations of grassy meadows, scrub and trees formed. This environment caused an explosion of biodiversity that occupied small niches in this great diversity of habitats and gave structure and resilience to those ecosystems.
The great extinctions of megafauna
Those open habitats dwindled at the same time that megafauna disappeared on most continents. Animals that exceed 40 kg in weight are considered megafauna. For a long time, the disappearance of this fauna was attributed to the periods of glaciation that have affected the earth in the last millions of years, and this is how the disappearance of the mammoths on the European continent was explained, for example. Now, however, we have many scientific studies that minimize the responsibility for the glaciations and place the blame on a rising species, man.
The great extinctions of megafauna have mainly affected the continents furthest from Africa. In America about 80% of the megafauna became extinct, consisting of mammoths, giant ground sloths, giant armadillos, horses and other species, in Australia 70% of the megafauna disappeared, in Eurasia 55% and only in Africa the extinction was lower, of only 16%, probably because man appeared earlier on that continent and the animals could get used to it over thousands of years.
On the contrary, when man arrived in America and Australia, the megafauna had no fear of him and did not run away, so the extinctions occurred within a few centuries after the first contact with man. It is precisely in Africa, where more megafauna have survived, where there are also more large open habitats such as savannahs and other spaces with pastures.
These major ecosystemic changes have also led us to assume that the natural habitat in Europe and other continents is extensive and dense forests, the climax of ecological succession. But new techniques for analyzing herbaceous pollen and silicic structures of grasses show us that these continents were also covered with large open spaces and all their associated fauna, much more diverse than that of the closed forest and thick
The new experiments of renaturation
Armed with these recent scientific discoveries, teams of conservation biologists are testing habitat restoration and biodiversity recovery techniques using large herbivores, with often spectacular results.
In Europe where the extinct cow species, the auroch, is no longer with us, ancient cow breeds that retain much of the auroch’s genetics are being used, or even bulls are being used , a mixed race of several ancient races and is being selected to resemble the known DNA remnants of the ancient aurochs .
Horses are also being used, especially the old breeds that resemble the old European horses, the Tarpans, like the horses of the Camargue, a very rustic breed that is used in several places in Catalonia, also known as astride a swamp. And the last of the large European herbivores is the European bison, very similar to the well-known American bison and which was saved only from the last 12 specimens that could be saved from extinction.
This new conservation technique, renaturation, differs from traditional conservation in several aspects, not without controversy from certain more traditional and institutional sectors of conservation. Just as traditional conservation starts from more recent points of reference, from several tens of years to a few centuries ago, renaturation takes as a point of reference the Pleistocene, the time before the great extinctions.
This point is correct, since as we have seen before habitats have evolved with the disappearances of megafauna, and renaturalization finds more open spaces as a reference, and traditional conservation starts from an ideal of more continuous forests in Europe.
Conservation until now has focused on the preservation of specific communities and biodiversity, with lists of threatened species, and renaturalization seeks the recovery of ecological processes and the re-establishment of nutrient cycles. It therefore has a more systemic approach.
Also, renaturalization achieves unsought communities and habitats, as the processes dictate the species that return, often causing unexpected biological surprises.
Oostvaardersplassen and Knepp, two pioneering European experiences
In Europe there are two pioneering and emblematic renaturation projects, the first at Oostvaardersplassen in the Netherlands, where ecologists described the impact of geese in creating open habitats and then supplemented with the introduction of cows and other large mammals with very good results.
And the other important project is the renaturalization of a farm of about 1,500 Ha in Knepp , in the South of England, where its owners stopped the traditional agricultural system they practiced and stopped plowing the land to feed cows in a farm that was getting poorer and poorer.
With the introduction of grazing processes with ancient breeds of cows and the reintroduction of beavers, they have managed to reverse the economic situation of the farm and at the same time recover the best populations of nightingales, wood pigeons and butterflies in the whole country. There is a very extensive and comprehensive book about this project written by Kepp owners Charlie Burrell and Isabella Tree in The Book of Wilding .
Renaturalization finds itself making the transition from ecological theory to management practice, not without initial opposition and setbacks, but it points to a new technique that will greatly increase in the future as scientific studies corroborate the theories on which it is based. supports this practice.
One of the advantages of renaturalization and in contrast to the environmentalist movement that began in the 1970s, is the message of hope it brings. Until now the message was mainly based on losses, extinctions, overpopulation problems and restrictions for the conservation of spaces and species, a more pessimistic message that many people no longer want to hear.
Renaturalization wants to bring a more positive message, of creating new models of coexistence with nature, compatible for example with quality pasture meat farms and tourism, innovation in management, technology and open expectations of its results
