Rewilding has been the topic of a couple of blog posts over the last few years  (for example here, in relation to the George Monbiot-narrated video about the wolves of Yellowstone Park; and also here, about the notion that perhaps we should also think about rewilding the human digestive ecosystem).

Since then there’s been a lot of activity with respect to rewilding, some of it practical and adding to the evidence base, some of it conceptual and controversial.  So I thought I’d do a quick round up of rewilding-related items I’d seen recently: feel free to suggest others.

In an open-access paper in Current Biology, entitled “Rewilding is the new Pandora’s box in conservation” David Nogués-Bravo and colleagues ask “what exactly is rewilding, and is it based on sound ecological understanding?”  Their conclusion is that “there is a worrying lack of consensus about what rewilding is and what it isn’t” and that “scientific support for the main ecological assumptions behind rewilding, such as top-down control of ecosystems, is limited”.  They go on to discuss the potential dangers of (re)introducing species into existing ecosystems, including both ecological and economic concerns.

Meanwhile Jens-Christian Svenning and colleagues have an open access paper in Proceedings of the National Academy of the USA about “Science for a wilder Anthropocene: Synthesis and future directions for trophic rewilding research” which takes a much more positive view of the potential benefits of rewilding, though still urges caution and further research, pointing out that “empirical research on trophic rewilding is still rare, fragmented, and geographically biased, with the literature dominated by essays and opinion pieces.”  Science writer John Carey provides some useful wider context to this discussion in a companion piece.

Subsequently Dustin and Daniel Rubenstein critiqued the Svenning et al. paper with an opinion piece called “From Pleistocene to trophic rewilding: A wolf in sheep’s clothing“, to which Svenning and colleagues replied: “Time to move on from ideological debates on rewilding“.

Svenning et al.‘s request for more empirical data on the effects of rewilding has been heeded this month by a study in Freshwater Biology from Alan Law and colleagues on “Habitat engineering by beaver benefits aquatic biodiversity and ecosystem processes in agricultural streams“.  Focusing on the recent reintroduction of beaver to Scotland, these researchers documented positive effects of the beaver on removal of inorganic nutrients from streams, and overall freshwater invertebrate diversity.

I find it really exciting that so much interesting debate and data are now being generated on the topic of rewilding: it’s fascinating and important science with a clear practical component that could leave the planet richer and in better condition for future generations.  It certainly deserves to be better funded, perhaps taking a slice of the “big science” pie from physics and astronomy, an argument that has been raised several times by Charley Krebs on his Ecological Rants blog.

As a researcher I don’t have a horse in this race (or even a Konick pony, such as are being used in a small-scale rewilding project at Wicken Fen). However I do wonder what a “rewilded” landscape would look like for pollinators in Britain, given that most of their diversity and abundance is associated with open grassland and heathland habitats, which were rare in these islands prior to human deforestation.  Having said that, a greater density of large mammalian herbivores can certainly open up woodland – see Bakker et al.‘s paper on “Combining paleo-data and modern exclosure experiments to assess the impact of megafauna extinctions on woody vegetation“.

As a teacher these discussions provide a lot of scope for interesting class exercises and seminars on the topic, which I’ll certainly be developing more next year.  Expect this to be an ongoing topic on the blog.