What Is Rewilding?
“Rewilding” is a complex, dynamic process that goes beyond conservation or protection of existing natural wilderness areas. With rewilding, the idea of a static state of nature to be protected from the contaminating influence of humans is gone, replaced by a more expansive vision of what could be.
Instead of narrowing the focus in on a particular, well-defined state of nature, rewilding expands the vision by considering multiple past natures for any given geographic location.
Instead of insisting upon the protection of nature in its current manifestation, rewilding seeks to implement ecological processes that will launch an ecosystem on a trajectory towards optimal biodiversity, given what is known about its multiple past natures, and present-day socio-ecological constraints.
Rewilding is at the interface between science and society, and offers an enticing new vision for anyone who might be concerned about our precarious ecological situation.
Rewilding Europe
Rewilding Europe is an organisation committed to implementing ecological processes and practices that ensure the real-world application of rewilding theory, as opposed to having it remain locked-up within the bounds of academic institutions. Rewilding Europe bridge the gap between intellectual findings and practical applications.
Principles Of Rewilding
Given the novelty of this concept, and its many different manifestations in the real world, “rewilding” lacks any clear-cut definition. However, there are certain general principles that underpin rewilding projects wherever they crop up on the globe. These principles make up the intellectual foundation for the real-world application of ecological processes and practices that set a given ecosystem on a trajectory towards the best possible potential future natures.
This is by no means an exhaustive list, but serves as a neat introduction to some exciting aspects of rewilding.
Shifting Baseline Syndrome
Each new generation first encounters a different kind of nature than the generation before. With each passing year, nature changes as it would do in the absence of humans. But human actions have both direct, and indirect effects on the surrounding nature. These effects may be so gradual as to be all but invisible across a small enough time scale. But across the lifetime of individuals, these small effects accrue, and result in a significantly changed nature that the generation after them will view as their baseline reference nature. Any nature that deviates too far from this new baseline will be considered abnormal or strange. This is the idea of “shifting baseline syndrome” in a nutshell. The baseline nature each generation uses as their reference nature (against which other natures will be judged) shifts across time.
Rewilding recognises that the nature first encountered by any generation is an extremely small snapshot of the many different kinds of nature that were present in a given geographic location across geologic time. The nature we see today is just one of the multiple natures that will have been made manifest across geologic time in that particular location.
Recent research findings suggest that ecologies of the past were far more biodiverse and biologically vibrant. Although an important conservation goal, protecting nature in its current manifestation is no longer a sufficient strategy for long-term ecological well-being, given what we now know about past ecologies. Rewilding casts its eye back to those many different kinds of nature, and uses them to inform a more comprehensive conservation strategy that not only conserves present nature, but encourages the emergence of the most biodiverse future natures.
Techniques in the field of paleoecology facilitate the reconstruction of past ecosystems. Ancient pollen and fossil record analyses allow paleoecologists to infer what past ecosystems may have looked like. Rewilding takes into consideration the multiple natures that may once have existed in a given geographic location. The information unearthed by paleoecologists provides a clearer picture of what once was, and suggests an enticing vision of what might be. Rewilding moves beyond conservation of what is, implementing processes that will facilitate the emergence of the most biologically vibrant nature in the future.
Megafauna Pasts
Connected to this idea of shifting baseline syndrome, and consulting multiple past natures to inform a more comprehensive vision of potential natures that could be, is the idea of megafauna pasts, and reintegrating megafauna species back into ecologies from which they have been extirpated.
Loosely defined, megafauna are organisms that weigh over 40kg when fully grown. These species used to be much more widely distributed across the globe. They could be found in almost every terrestrial ecosystem. So where have they all gone?
Although it remains a topic of intense debate, there’s fairly conclusive evidence that Homo sapiens over-exploited the rich abundance of herbivorous megafauna species to the point of local, and eventually global, extinction. There is a tight correlation between the migration of humans across the globe, and the concurrent disappearance of megafauna species.
Regardless of the main driver of extinction, one fact remains indisputable, the megafauna of the past have become functionally extinct. One of the guiding principles for rewilding is to re-establish the ecological functions once fulfilled by megafauna across the globe.
Woolly mammoths, rhinoceros, giant ground sloths, and elephants are all large, herbivorous organisms who tend (or tended!)to organise into herds and affect their surrounding ecology in ways that increase biodiversity.
- The woolly coats of these megafauna could support a vast array of insect and tick species which were themselves the foodstuff of many bird species.
- Megafauna dung was excellent fertiliser for the grasslands, and was a microcosm of biodiversity unto itself. Megafauna excrement would have been in high supply, so the organisms that figured out how to capitalise on this abundant resource could rest assured their bellies would never be left wanting. Dung beetles evolved specific means by which to process megafauna faeces and derive nutrition from them. Zooming in even closer to the dung, it would have supported a diverse array of microorganisms such as saprophytic fungi and bacteria.
- Certain megafauna behaviours, the likes of wallowing and knocking down young trees, also contributed to increasing biodiversity. These behaviours create micro-habitats, such as bare ground and dead wood, that support organisms that would otherwise have no place to live. Reptiles like lizards and snakes gravitate towards the bare ground as it is a place they can sun themselves and heat up. Woodlice and other insects require dead and decaying wood to survive and thrive.
Disturbance Regimes
Again, returning to this notion of consulting multiple past natures to more comprehensively understand the true potential for nature recovery in any one geographic location, and re-establishing missing ecological functions that were once crucial to maintaining biodiverse landscapes, disturbance regimes are becoming more widely recognised as necessary temporary phenomena with an outsized effect on long-term biodiversity.
As mentioned above, megafauna behaviours such as wallowing, trampling, tree-knocking, grazing and browsing all contributed to the maintenance of a continental-scale, biodiverse, mosaic-like patchwork of heterogenous habitats. Megafauna disturbance is not the only disturbance regime nature benefitted from in the past. Changes in temperature across various time scales (such as day and night, or seasonal differences), and wildfire disturbance also contribute to biodiversity. But the disruptive actions of megafauna deserve special attention, as their absence has brought about qualitatively different present natures compared to what they once were in the past.
Some Call Them Keystone Species
Species who disproportionately affect their surrounding ecology are sometimes referred to as “keystone species”. This evokes the image of a keystone arch, at the top of which is the keystone. The keystone in the one stone that holds the arch together. Without the keystone, the arch crashes and crumbles onto the ground.
The collective action of a few individuals who are part of the same keystone species disproportionately affects the ecological structure and/or dynamics of the ecosystem they are operating in. Megafauna species are considered keystones as their behaviours have a disproportionate effect on ecological succession. Their collective actions ensure the maintenance of a heterogenous landscape with a mixture of grassland, shrubland, and forested areas. The arch itself is the state of nature, and the keystone ensures a particular state is maintained. Without the keystone, that particular nature disintegrates, and is downgraded to a different state of nature.
The concept of a keystone species is a useful starting point for understanding the importance biological organisms play in maintaining a particular state of nature. But nature is far more complex than that analogy would suggest. Rarely is it the case that one species single-handedly maintains a particular state of nature. It’s better to think in terms of webs of interacting species. Multiple species each bringing a different set of functions to the table. And when those functions interact, new functions that were previously absent, and impossible to attribute to any single species, emerge. A good example of this is the effect of reintroducing wolves back into Yellowstone National Park had on the course of the river. Prior to their reintroduction, it would have been difficult to predict that the wolves would affect the movement of a river. There is no direct connection between wolf function and river movement. But indirectly, through the presence of wolves and the landscape of fear they create for their prey, the river changed its course. The wolves forced large herbivores, such as deer, to retreat to forested areas sooner than they would like, which reduced grazing pressure on the banks of the river. This allowed riparian tree species to recolonise the river banks, and stabilise the soils there. As a result, the river could not as easily erode its banks, and began to run a narrower path, as opposed to a wide meandering one.
It was through the interactions between species, predator-prey dynamics and riparian tree species, that the reintroduction of wolves into Yellowstone changed the course of a river. Although you could say the wolves are a keystone species, they alone are not maintaining the current state of nature in Yellowstone. They, along with their innumerable interactions with other species, are maintaining the current state of nature in Yellowstone. It’s an important nuanced point that must be grasped to better understand the complexity of rewilding, and ecology in general.
We might just be better off referring to “functional species”. This term accounts for the importance of a given species, but doesn’t pedestalise the one species above all others. It hints at the embeddedness of that species within its environmental context, and the relationships with its biotic and abiotic environment.
Rewilding as Part of a Paradigm Shift
By now, the distinction between conventional conservationism and rewilding should be a bit clearer. The magnitude of possible change with rewilding far exceeds that of traditional conservationism. When conservationism first emerged, it was utterly necessary. This was a time when humanity turned back and cast an eye over the trail they had left in their wake after blazing across the globe at breakneck speed, and pushing the nature they had first encountered back into the fringes and margins. They correctly intuited that this nature should be protected and preserved.
But this impulse towards protectionism has run its course. It has reached its point of paradoxical counterproductivity, and is now impeding the progress it knows full well it must achieve. Protection alone is no longer sufficient for the type of nature recovery we 21st century modern humans are tasked with facilitating.
Rewilding is but one of a number of actionable concepts that stems from the old ways. Now that those old ways have run their course, it is up to us to catalyse further progression towards the ultimate goal of long-term sustainability and complete ecological compatibility.