Rewilding - An approach to ecosystem management

'Rewilding' is an ecological concept that is relatively new to me and something that I am increasingly interested in. 'Rewilding' is the large scale restoration of ecosystems and natural processes driven in part by the reintroduction of missing species. Between now and beginning my Master's in September I hope to explore this concept further.

Moorhouse and Sandom (2015) present the example of the water vole, Arvicola amphibius, to outline various approaches to conservation. The water vole thrived in Britain since the start of the Holocene but

"since the 1930s the national population has been reduced to (much) less than 2% of its original size" - (Moorhouse and Sandom, 2015, p.45).

Arvicola amphibius - The Water Vole (take from http://www.arkive.org/water-vole/arvicola-terrestris/)

This rapid reduction in population size has mainly been a result of habitat loss due to agriculture and predation by the American mink, an introduced species.

3 approaches to managing the water vole present themselves. Option 1 would be to do nothing, allowing populations to become restricted to the few wetlands remaining that can protect them from predation. Option 2 would be to control mink populations coupled with reintroduction (the approach that Britain has taken). Finally option 3 would be to completely eradicate the American mink, restoration of all lost habitats and targeted water vole reintroductions.

Moorhouse and Sandom (2015) go on to say that approaches such as option 3 will always mean that the natural state has been irrevocably lost and that the best we can do is create a new state that is more functionally natural. They raise an interesting question on where the line can be drawn with regard to Britain's 'natural species'.

Rather than such a species orientated approach 'rewilding' asks what natural processes (migration, predation, flood prevention etc.) have been lost and whether this has been the result of human intervention. Moorhouse and Sandom (2015) outline the reintroduction of a top predator, the wolf, as an example of how this concept may work. 

Step 1 - Reintroduce top predator

Step 2 - Herbivory reduced

Step 3 - Increased woodland regeneration

Step 4 - Improved beaver habitat

Step 5 - Increased wetland availability

Step 6 - Improved water vole habitat

Of course there will be risks and objections to such schemes and natural feedback mechanisms will never allow such a smooth transition between steps but as a holistic approach to ecosystem conservation rewilding is one that intrigues me. I have ordered 'Feral' by George Monbiot and will continue to explore rewilding as an approach to conservation.

Some links to get me started:

http://www.theguardian.com/environment/2014/sep/19/-sp-rewilding-large-species-britain-wolves-bears
http://www.wildlifetrusts.org/rewilding
http://www.monbiot.com/2013/05/27/a-manifesto-for-rewilding-the-world/
http://www.rewildingeurope.com/

References

Moorhouse, T.P. and Sandom, C.J. (2015) Conservation and the problem with 'natural' - does rewilding hold the answer? Geography. 100 (1), p.45-50.