Friday, 24 January 2014

Holes in the re-wilding versus conservation debate.

The current discussion on re-wildling is extremely healthy but I am worried that both “sides” have left a gaping hole in their logic.  This hole relies on a myth, a myth that goes something like this:

Natural processes equal succession, conservationists fight succession so conservationists are fighting nature.

Rewilders say this is a bad thing because conservationists ignore natural processes.

Conservationists say this is a good thing because current nature is the product of thousands of years of interaction between people and wildlife so we need to continue that interaction.

This is presented as two opposite approaches, poles apart, different traditions, different philosophies, each blackening the other.  Rewilders claim that conservationists are playing God, making nature do what they want.  Conservationists claim that rewilders threaten to devastate whole habitats whilst chasing an unknown dream.

The problem with both sides is the starting point.  This is the presumption that nature equals succession. 

At a simplistic level it makes sense.  Succession is the process by which, if you leave an area alone, it goes through a process – starting with small plants, then taller plants, eventually scrub forms, then trees and then the trees grow up to form a forest – the end!  Sure enough – leave an area alone and that is generally what does happen.  So everyone believes it.  But this leaves out so much of the story that it is, broadly, nonsense.

Trotting out this simplistic nonsense still bedevils our television screens with any number of countryside programmes saying how “all this would have been dense trees before man cut them down”.  We literally do not know this.  It is not possible to claim what wild nature would have looked like and it is certainly not possible to claim it was all one type of favourite habitat (such as woodland).  Anybody referring to a past, unknown, wild landscape should be far more humble in terms of what they think it might have been like.

Rewilders and conservationists have a problem – open habitat.  To rewilders open habitat, like heathland, meadows, wetlands and moorland, are hated examples of human exploitation.  To conservationists they are loved examples of how sensitive management delivers diverse cultural landscapes, richer than boring tree-covered wilderness.  Both are wrong. 

A significant proportion of our plants and animals rely on open habitat.  About half are open habitat species, about half of the rest rely on forest edge habitats and even many of the deep forest species still rely on open habitat for some part of their life cycle.  If the natural state of Britain was dense forest then our flora and fauna would be dominated by shade-loving species.  It is not – most species are light demanding.  This cannot be explained by small, temporary gaps in the wild forest (see “The myth of the dense wildwood” in my November 2013 blog).  Whatever it was like, the primeval forest must have been a wonderful, diverse place containing the precursors of all the habitats we have today.  It is most unlikely that they were virtually absent (as some rewilders believe) and it does not make sense to claim that they were just made by humans (as some conservationists believe).

So – starting again – what are the natural processes that might have been active in a wild system, and what can we learn from this?  This is the interesting question that should be of interest to both rewilders and conservationists.

Natural processes are many, diverse and complex.  To simplify (probably over-simplify) you could think of them as working in two directions.  Succession going in one direction, heading towards some form of conceptual “climax” forest; natural disturbance going in the opposite direction, effectively turning the clock back on succession.  What is more, this would work at all sorts of scales and time scales.

Natural disturbance is not a bad thing – I spent years after the 1987 storm explaining the ecological benefits of storms.  Indeed habitats with low rates of natural disturbance tend to be relatively poor.  Technically, natural disturbance is termed the “initiator of vegetation dynamics”.  It’s the thing that makes vegetation change, opening up habitats, developing new niches and generating more living space for more species.

Wind storms, flooding, erosion, accretion, fungal disease, insect attacks and the action of grazers and browsers are key forms of natural disturbance.  But even these are just examples  – if you observe nature you can see all manner of disturbance events that influence vegetation and habitats.

But it is not just the animals or processes that have a direct effect on vegetation that matter.  Predators also have a major impact by significantly altering the behaviour of herbivores through “the ecology of fear”.  Predators influence where grazers graze and so influence where trees regenerate.  This has a huge beneficial effect on how the whole ecosystem functions (see my review of “Where the wild things were” in my blog of August 2009).

Rewilders, pushing all this aside in order to promote a favourite wooded habitat are not rewilding at all – they are just creating another human artefact.  Excluding natural disturbance is just as artificial as management.  It is like taking the engine out of a car and claiming it will go faster!

Rewilding is not a matter of leaving a restricted, degraded nature to fend for itself.  Instead it should be about understanding and re-establishing the natural processes that should be active in an area.  Sometimes this might be through non-intervention (see my blog on a present day wildwood, in November 2013), but not always.  George Monbiot in his book “Feral” goes some way in this direction but then gets lost in a desire to attack conservationists.  As George says, rewilding should be about establishing natural processes and then allowing nature to find its own way without setting an end point.  He then lets himself down, setting an end point by saying that it all must be dense forest.

The agenda for conservationists and rewilders should come together at this point.  We should become ecologists again by trying to understand nature and natural processes then use this knowledge to inform what, where and how much management should be put in place.  This is part of the value of wild places - places where we can learn from nature functioning for itself. 

But what about situations where the full range of natural processes cannot be restored?  This will be the normal situation in conservation – generally we are looking after a restricted and degraded nature.  Natural disturbance may be absent, limited, constrained in time and space, or simply cleaned away. Grazers may be present, but not having a natural effect on vegetation, and predators will almost certainly be absent.  So, desirable as it may be, we will not be able to re-establish the full range of natural processes, for example, in an urban greenspace a couple of hectares in size.  This is where conservation management comes in.  If we have wild places with nature functioning for itself then we should be able to develop a better understanding of how to mimic natural processes through conservation management.

And we should not forget those thousands of years of interaction between people and wildlife.  Conserving what we’ve got now must be the starting point.  But we must also be aware of “shifting baselines” – what we have now is not the best that we can have, we can imagine better and rewilding can drive us in that direction.



willowarch said...

Hi Tony, interesting series of blogs. I am someone who has been actively involved in nature conservation for 20 out of the last 30 years. I have recently come back to find a world of mitigation, protected species, biodiversity offsetting and the like and I can't say its a world that makes much sense.
I am attracted to rewilding, because I like its simplicity. Where I live in South Wales I am constantly seeing areas that are re wilding following the end of coal mining and steel. Some of them are turning into woodland or scrub, others are mixed heathlands and yet more are still bare rock or slag tips.
There really is no need to pay landowners in the uplands to manage their land, just take away all the subsidies. I don’t think it matters what happens, there just needs to be a trust in Nature to do what it does best. If landowners decide they can afford to keep livestock, so be it and I don’t have any objection to quarrying or wind farms as long as at the end of their lives, rewilding is allowed to take place afterwards.
I don't believe that ecologists and nature conservationists are capable of escaping from their mindset of valuing one species, habitat or process more than another. Rewilding offers a common sense alternative that not only works with Nature, it costs very little to the taxpayer and is sustainable,
Thanks Alan Bateman

Mark Fisher said...

So, the proportion of habitat must equate to the proportion of species? This is a linear relationship? Please tell me you don't rely on "Rewilding" Europe for your ecological understanding.