A contest between trees and animals - the grazing mosaic tendency


A running joke over the years has been that when it came time to write my memoirs, its title would be “Green is just a colour”. However, the more I reflect on my lack of impact in establishing in the minds of people in Britain an ecological basis for rewilding that is no different from America, or any other continent, then I have revised that to “Leaving a stain on the pages of history”. Another really naff book has come out on rewilding Britain, the basis of which is nonsense. I may not get around to writing the definitive book on Britain, but in the meantime, its back to the books on the American experience to show how really naff it is.

I took on a personal ordinance some years ago not to read too many books on the experience of wild nature in America, but instead look for British writers who could articulate an equally coherent view, in spite of the obviously poorer state of our wild nature. I worried that it would be too easy for me to get lost in reverie at the astonishing spectacle of wildness that I had seen in America and could read about, when the imperative was to confront the ineptitude in Britain to consider that our ecology is more than just its ability to survive in highly modified landscapes (1). It’s been a largely fruitless struggle to find British authors with this perspective (2-6). Would I be the one to write the book? Well, I have written a chapter on the ecological values of wilderness in Europe, as I could see that was something which would resonate with a wild experience that is still possible in continental Europe (7). It followed on logically from when I was able to tie wild land in Europe to the major areas of distribution of the large carnivores, and with the strictly protected public lands in the national protected area systems, these often connected through national ecological networks (8) as well as subsequently showing that areas with a wilderness characteristic existed in those protected area systems through drawing up a criteria-based register in Europe (9). I feel I have established, at least for myself, that ecology isn’t something different depending on which continent you are on, that when I read about trophic ecology in America, the interaction between all trophic levels in complete food webs, I have every reason to believe that the same ecological and evolutionary processes exist here if we were to get out of wild nature’s way.

A contest between trees and animals

It could be my lack of impact, but that this fundamental observation falls on deaf ears here is more than just a lack of relatable experience. It’s worse than that because, like the history of landscape paintings and its cultural conditioning, nature writing in Britain is willingly constrained within a fashion that sees it tied to people and their activities, falling in line with the type of landscape that the land use of private ownership wants, rather than what it could be (5,10). If I needed any greater proof of this beyond what I have documented so often before, then the latest offering from a new author, Benedict Macdonald, an obvious birdist, just confirms my belief, a book within its first few pages that is aggressively assertive of the “grazing mosaic”, the failed fantasy of Frans Vera who is name-checked by the author, but which is entirely within the current fashion of a one-eyed view of wild nature, and with every evidence lent in support of that, irrespective of its logic or validity (11). It is the hackneyed invocation of extinct Pleistocene tree-abusers like rhino, hippopotamus and Monbiot’s straight-tusked elephant (4,12) followed by a modern-day fulfilment of Holocene tree abusers through cattle as substitute for aurochs, the never ending wish fulfilment that wild horses exist, and even bison as territorially appropriate in Britain through the utterly tenuous connection of a piece of bone that was dredged up from Doggerland – all these as the herbivores instrumental in creating a “mosaic of trees and open land: a mosaic that pre-dates any kind of human farmland”. The not-so-subliminal message here is that farmland is the true state of our wild lands and which, allegedly, all our wild nature, our butterflies, bats, beetles, beavers, boars, moths and birds are dependent on. The author goes further with this claim – “It is also illuminating how disturbed open ground is perhaps the single most important habitat for the survival of most of Britain's wildflowers, too”

If you are not aware how self-serving these claims are, how divorced they are from ecological reality, then you only have to pick up a few guidebooks on British nature and look for the woodland shrubs, plants, ferns, fungi, lichens, mosses, and bacteria; the woodland birds, mammals, bats, and invertebrates; and consider whether all these species can form their commonly observed phytosociological and other community associations with just a few scattered and isolated trees, because that is the implication of what is being asserted. The author cloaks his argument, which he believes is a “better-supported and infinitely more logical idea”, as a war, a “contest between trees and animals”, a “simple fact that Britain's trees did not grow uncontested”, that trees have to “fight against wild grazers”, the outcome of the war being that “large herbivores shaped the formation of our habitats”. We then get to the nexus of the justification upon which this author build his proposals for “rebirding” Britain through rewilding (11):
“The rewilding studies of Frans Vera, in the Netherlands, and Charles Burrell, in Sussex, have shown that where small cattle herds roam wild, oak trees do not grow in 'forests' but must fight their way through thorn scrub if they are to survive. This is one of the most compelling reasons why a closed-canopy forest cannot form. It can only do so, indeed, if Wild cattle are taken out of the picture”

There are three fallacies inherent in that paragraph. Neither Frans Vera at the Oostvaardersplassen in the Netherlands, or Charlie on his heavily subsidised farm in Sussex, have produced any proof that this basic tenet of Vera’s fantasy theory about woodland creation, that trees only develop if they are protected against herbivory by thorny scrub, has any validity. In the case of the Oostvaardersplassen, the trophic imbalance of an irrupting population of herbivores trapped behind fences led to massive ecological degeneration where no tree survives, nor even thorny scrub, and where the food-limited carrying capacity was exceeded each winter resulting in mass starvation (6,13). The explanation is simpler at Knepp, Charlie’s farm, where the scrub, the main attraction to the in-migrating wild nature, developed there in the absence of herbivores, the grazing being applied afterwards, so making irrelevant any impact of thorny scrub (6). The third fallacy is that the author has no understanding of trophic ecology, the influence of large carnivores in natural systems in their impact on herbivores in both a density and behaviourally mediated way so that there is a spatial pattern to the observed effects of herbivores. At its simplest, is it likely that a wild herbivore will linger to browse near a wolf den, or other areas where they don’t have good lines of sight and evasive retreat? That’s how woodland forms and is protected against herbivores, how the herbivores are “taken out of the picture”. The absence therefore of any consideration of trophic ecology, the interaction between carnivores, herbivores and the plant material they eat, pretty much renders this book as nonsense.

Six interrelated lines of scientific inquiry

Why does this grazing mosaic tendency attract such one-eyed absolutists who gravitate to and then congregate every year at Knepp where they reinforce each other’s prejudices?(14) Would that this author read some American books before he pontificated, but I suspect there is a wilful narrowing of vision when somebody sets out within this British constraint on acceding to ecological reality so that it wouldn’t make any difference. I have broken my own ordinance three times in recent months in reading American books, first with Dave Foreman’s from 2004 about rewilding North America, as it was so central to the etymological study I carried out on the evolution of the meaning of rewilding within the periodical Wild Earth and The Wildlands Project in the decade or so leading up to that book (15,16). Given the focus I had, I was less interested in the first part of the book that recounted the “Bad News” of the processes of extinction and the crisis that Foreman believed faced America through the ecological wounds of direct killing, habitat loss, fragmentation, loss of ecological processes, exotic species, pollution and climate change (17). It was the “Good News” and “Taking Action” of the second and third parts that helped me understand the importance of the science of conservation biology in being the underpinning of rewilding, and how it informed the approach taken.

In the second part, Foreman saw that six interrelated lines of scientific inquiry arose from conservation biology that had led to the sort of wildlands networks that were proposed by The Wildlands Project and its partners, each being briefly explored: extinction dynamics, island biogeography, meta-population theory, natural disturbance ecology (18) large carnivore ecology (19) and landscape-scale ecological restoration. A rewilding focus on Continental-scale conservation lays out a vision of a North American Wildlands Network that introduces the concept of a connected wildland system based on linked core areas, the linkages addressing habitat fragmentation and landscape permeability (20). It is on the basis of the latter, the areas of the American continent that still retained some capacity for free movement of species, that lent themselves to the identification of four Continental MegaLinkages, one sweeping up from Central America to Alaska, and which has a spur that comes up from Baja California and along the Pacific Coast to join it at the American-Canadian border; a connection from Alaska across to Labrador with a dip down into the Great Lakes region; and a linkage from the Canadian Maritimes down through the Appalachians and ending in the Everglades in Florida (21). Foreman explains that the choice of these MegaLinkages did not mean that conservationists should ignore the more domesticated and fragmented areas of America, especially when some of them, such as the Tennessee River system, hold most of the imperilled diversity on the American continent. Here he thought the existing approach to nature reserve protection and restoration should continue, but with a more ambitious vision.

Foreman then looks at the historical and current processes for selecting and designing wild areas, and the importance of wilderness to overall ecosystem health. It is often a false accusation that The Wildlands Projects approach was solely focussed on wilderness restoration, plunging it into the subjectivity surrounding that concept and its perception (22). What is overlooked in this accusation is that wilderness to The Wildlands Project is a protected area designation in America that met the needs of its rewilding approach to conservation in that it delivers strict protection to core areas identified to support as much as the regional diversity as possible (23,24). Why wouldn’t you want to give strict protection to wild nature, and any gains achieved for it through rewilding, so that they could be secured in perpetuity, rather than be subject to the changing whims of land ownership? Isn’t it natural justice to do so? Ownership is the distinction, as wilderness designation is a legislative protection in America that can only be applied to publicly owned land, thus explaining the emphasis on public lands and wilderness seen in The Wildlands Projects approach. Thus adding to existing wilderness areas or seeking to have new areas of wilderness designated was seen as a necessary expansionist approach if there was insufficient core space available to meet those needs of capturing regional diversity, especially of wide ranging species.

The third part starts with a detailed description of the component areas of a wildlands network, the cores, compatible use areas and wildlife movement linkages, how design of the network is based on the needs of a set of focal species, and the fieldwork that is needed to back that up. He finishes with listing several land management reforms that Foreman believes are necessary for successful implementation of the network, such as reforming wildlife management to adopt a more ecological approach; reintroducing highly interactive species such as large carnivores and beaver; establishing species recovery goals for ecologically effective populations (25); protecting roadless areas on public lands (26); removing livestock from most public lands and getting rid of abandoned and unnecessary fencing; establishing landscape permeability as a public land management goal; encouraging ecological management of private and tribal lands important for wildlife linkages; restoring a natural fire ecology; and prioritising removal of exotic species that threaten native species and wildlands.

A science workshop of thirty invited experts

I first came across Foreman’s book in 2007 when extracts of it were used to build thematic pages on the Rewilding Institute website, the organisation that Foreman set up after he left The Widllands Project in 2004 - they are still in use today (18-21,25,26). I can’t say for sure, but this book may have been an early casualty of my ordinance, but having read it now in its entirety, it has to be essential reading for anyone who wants to know what rewilding really is, taking away any excuse that there is little definitively available about its original meaning. Foreman freely admits in his book that he is no scientist, I would suggest though that he is a great interpreter of it, but another book caught my eye while researching the etymology because it was published as a result of a science workshop of thirty invited experts. It was organised by Michael Soulé for The Wildlands Project, and took place at the Rex Ranch near Tucson, Arizona, in November 1997. The workshop was designed so that the outcome would become a book that would be a guide to the science behind designing a more effective way to protect nature, wilderness, and biodiversity. Thus sessions were scheduled with each of the main chapter titles as their theme, such as scale in selecting and designing biological reserves, regional and continental conservation, the regulatory role of large carnivores, cores areas, connectivity, and buffer zones.

The book that was subsequently published in1999 was called Continental Conservation: Scientific Foundations of Regional Reserve Networks (27). In the first chapter, on the policy and science of regional conservation, Soulé and Terborgh discussed what they saw as one of the central issues of the book, that the viability of ecosystems often depended on the viability of species whose interactions regulated the systems. Thus the size of the system, its configuration of boundaries and corridors, must accommodate the needs of a critical handful of highly interactive species, these species often including large carnivores. They noted that the “goal of maintaining viable populations of keystone species, particularly large carnivores, has been referred to as "rewilding””. They observed that rewilding was the latest element in the history of scientific conservation, and that it complemented rather than replaced other approaches for designing regional networks of nature protection, as it contributed an independent justification for large scale and connectivity. Moreover, like certain other methodologies, rewilding facilitated design and management of protected areas because it obviated the need to consider every species in detail – “Thus rewilding is both an end (because of our duty to repair past mistakes in management) and a means by which the viability of conservation units is achieved. This unusual conjunction of means and ends is, perhaps, the most intellectually compelling feature of rewilding”. Their observations on rewilding and connectivity exemplified this - “Nature is now in pieces, and rewilding is a justification for restoring connectivity on a regional or landscape level”. They emphasised that connectivity was not just another goal of conservation because it was the natural state of things. Thus the isolation created by the consequences of fragmentation at the habitat and landscape scale needed reversal to restore the effective exchange of individuals and materials among sites for genetic maintenance, for demographic stability, for migration, and for the sake of other ecological processes.

In another chapter, Terborgh and others wrote extensively on the role that top carnivores play in regulating terrestrial ecosystems. The authors acknowledged that the role that top predators play was considered ill-defined and contentious, pointing to one review that had concluded that top-down community regulation, as envisioned by trophic-level theories, was relatively uncommon in nature. However, the authors asserted that after reviewing an overlapping body of literature, they had come to the opposite conclusion. The evidence they had reviewed overwhelmingly supported the strong top-down role of large carnivores in regulating prey populations and thereby stabilizing the trophic structure of terrestrial ecosystems. They consequently explained - “Simple predator/prey models describe feedback processes leading to a stable point or stable limit cycle, in which the numbers of predators and prey come to equilibrium or oscillate within circumscribed limits”. I was pleased to come across this interpretation, as it lends credence to the observation I made previously that the predator-limited carrying capacity for herbivores, what could be described as the ecological carrying capacity, is an indication of what a natural level of grazing might be, as it is the poise of an ecosystem at full trophic occupancy (13,28,29). It is signally missing from places like the Oostvaardersplassen and Knepp, as is recognition of what Terborgh and colleagues went on to explain, that top predators were often essential to the integrity of ecological communities, their influence felt by way of a cascade of interactions extending through successively lower trophic levels to autotrophs at the base of the food web. They sounded a note of caution (27):
“Loss of top predators resulted in hyperabundance of consumers playing a variety of trophic roles (herbivores, seed dispersers, seed predators) and in mesopredator release. Hyperabundance of consumers and mesopredarors, in turn, resulted in trophic cascades that led to multiple effects -including the direct elimination of plant populations from overbrowsing/grazing, reproductive failure of canopy tree species, and the loss of ground nesting birds and probably other small vertebrates”

Widespread elimination of top predators from terrestrial ecosystems had disrupted the feedback process through which predators and prey mutually regulated each other's numbers, and which may cause a cascade of ecological effects that speeded extinction. Terborgh and his colleagues believed therefore that efforts to conserve North American biodiversity in interconnected mega-reserves would have to place a high priority on re-establishing top predators wherever they had been locally extirpated. In my recent correspondence with John Terborgh, he noted that Europe had come further in allowing top carnivores to repopulate the landscape than they had in America. He was referring to the westward reinstatement of the wolf such that there is a presence now in every continental European country, whereas gray wolves in America currently occupy less than 10 percent of their historic range, and roughly 30 percent of currently suitable habitat arrived at through modelling (30-32). Terborgh put the difference down to tolerance, which he said America had regrettably little of. I would suggest that it is more likely than just tolerance to be due to the strict protection afforded the wolf under the EU Habitats Directive and the Bern Convention that obliges governments to take a mature, national approach to the voluntary reinstatement of wolves as they redistribute across Europe, that protection staying constant (33). In contrast, while America does have the Endangered Species Act, it has been counterproductive to delist from protection the wolf in Wyoming, Idaho, and Montana, with the result that they get slaughtered, when they are just starting to reappear in places like Northern California and the Pacific Northwest as a result of out-migration from the delisted states (30). Moreover, the proposal to strip federal Endangered Species Act protections for wolves across nearly the entire lower-48 states, except for a small population of Mexican wolves in Arizona and New Mexico, will reverse gray wolf recovery in the United States at a stage when they are still functionally extinct in the vast majority of their former range across continental America (34). Terborgh had better news on panthers in Florida, where a female had appeared on the northern side of the Caloosahatchee River and bred for the first time in over 40 years (35,36). The river has confined the Florida panther population to the Everglades, so having a breeding female north of the river was a break-through. He hoped for more of those. In contrast, when I asked, he was less sanguine that reintroducing a few horses and aurochs-like cattle to a fenced in pasture could be called rewilding.

5,000 miles between Mexico and Canada

I was taken by the chapter on core areas by Reed Noss and colleagues where they are described as the central component of a landscape design for conservation, and where “human uses are greatly restricted and natural processes reign”(27). They regarded core areas as essential for meaningful conservation, and considered conservation strategies that lacked meaningful core areas are “naive, arrogant, and dangerous”. You have to feel that this is a contempt deserved of Britain, the importance of strictly protected core areas connected through the landscape seemingly a hopeless wish when the mush of Knepp is popularly perceived to be the zenith of rewilding ambition here. Other chapters in this book, while they were key aspects of Continental Conservation as an approach, failed to hold my attention as much. I had perhaps been spoiled by reading the visions and approach for rewilding that had been conveyed through Wild Earth and the various Wildlands Network Designs based on them, that the chapters came across as literature reviews, particularly the chapter on corridors, rather than applications to conservation. But then I stumbled over what became my third American book to read, and in which corridors were writ large. It is a remarkable journalistic account of the research carried out by Mary Ellen Hannibal on Spine of the Continent, the MegaLinkage that stretches 5,000 miles between Mexico and Canada, tracing the Rocky Mountains as it goes (37). I cannot do justice to it here, as it demands space of its own to describe the mix of characters she talks to, some of them familiar to me and who I have met or corresponded with; the stories she tells of the people involved and of her excursions along the Spine with these people, often carrying out voluntary work with them in searching for wild animals; the natural history she observes while doing it, and both the contemporary and early science that informs the thinking behind this essential roadway for animal and plant migration and dispersal. It doesn’t matter that it is a very American book in style, that it is rooted in an extant complex ecology that hasn’t been part of Britain for centuries, because it tells the story of people committed to wild nature at an expansive scale, each working on their section of the Spine, and being advocates for how we live with giving wild nature its own space into the future (and see this account, a rarity in Britain (38)). It’s the kind of book I would hope to write about Britain.

Mark Fisher 12 June 2019

(1) Fisher, M. (2009) Ecological incompleteness and our missing top predators: learning the lessons from abroad. Wilder Horizons 1(1): 14-16

(2) Wildernesses of the Mind, Self-willed land January 2005

(3) Wild trees and natural woods, Self-willed land April 2013

(4) Reflections on Feral, Self-willed land January 2014

(5) Breaking the pattern, Self-willed land October 2016


(6) More zombie ideas in ecology, Self-willed land March 2018

(7) Fisher, M. (2016) Ecological values of wilderness in Europe. IN Bastmeijer, K. (Ed.). Wilderness protection in Europe: the role of international, European and national law. Cambridge University Press. ppg. 67-93

(8) Fisher, M., Carver, S. Kun, Z., McMorran, R., Arrell, K. and Mitchell, G. (2010). Review of
Status and Conservation of Wild Land in Europe. Wildland Reserch Institute, University of Leeds

(9) A.T. Kuiters, M. van Eupen, S. Carver, M. Fisher, Z. Kun & V. Vancura Wilderness register and indicator for Europe. Final report October 2013. Contract No: 07.0307/2011/610387/SER/B.3

(10) Looking at the landscape view, Self-willed land April 2014

(11) Macdonald, B. (2019) Rebirding: Rewilding Britain and its Birds. Pelagic Publishing Ltd

(12) Ecological restoration in modified landscapes, Self-willed land June 2013

(13) Using functional traits - walking rewilding and wolves straight into the criticism of Goldilocks Standards, Self-willed land June 2018

(14) FREEING THE LANDSCAPE: Grazing animals as ecosystems engineers, THE KNEPP VERA CONFERENCE 2017

(15) An ecological landscape – connectivity, cores and coexistence, Self-willed land March 2019

(16) Fisher, M. (2019) NATURAL SCIENCE AND SPATIAL APPROACH OF REWILDING –evolution in meaning of rewilding in Wild Earth and The Wildlands Project. Self-willed land June 2019

(17) Foreman, D. (2004) Rewilding North America: a vision for conservation in the 21st century. Island Press

(18) Ecological and Evolutionary Processes (Adapted from Dave Foreman’s Book “Rewilding North America“) Rewilding Earth - the home of the Rewilding Institute

(19) Top-down Regulation of Ecosystems by Large Carnivores (Adapted from Dave Foreman’s Book “Rewilding North America“) Rewilding Early - the home of the Rewilding Institute

(20) Landscape Permeability (Adapted from Dave Foreman’s Book “Rewilding North America“) Rewilding Earth - the home of the Rewilding Institute

(21) The North American Wildlands Network: Four MegaLinkages (Adapted from Dave Foreman’s Book “Rewilding North America“) Rewilding Earth - the home of the Rewilding Institute

(22) Perino, A., Pereira, H.M., Navarro, L.M., 1,2, Néstor Fernández, N., Bullock, J.M., Ceaușu, S., Cortés-Avizanda, A., van Klink, R., Kuemmerle, T., Lomba, A., Pe’er, G., Plieninger, T., Rey Benayas, J.M., Sandom, C.J., Svenning, J-C, and Wheeler, H.C. (2019) Rewilding complex ecosystems. Science 364: eaav5570

(23) Wilderness Designation FAQs, The Wilderness Society

(24) THE WILDERNESS ACT OF 1964, U.S. Department of Justice

(25) Ecologically Effective Populations For Highly Interactive Species (Adapted from Dave Foreman’s Book “Rewilding North America“) Rewilding Earth - the home of the Rewilding Institute

(26) The Need For Roadless (Wilderness) Cores (Adapted from Dave Foreman’s Book “Rewilding North America“) Rewilding Earth - the home of the Rewilding Institute

(27) Soulé, M. E., & Terborgh, J. (Eds.). (1999) Continental conservation: scientific foundations of regional reserve networks. Island Press.

(28) Moving past process to outcome – the manifestation of wild land, Self-willed land September 2017

(29) Rewiring an emptied food web, Self-willed land January 2018

(30) Endangered and Threatened Wildlife and Plants; Removing the Gray Wolf (Canis lupus). A Proposed Rule by the Fish and Wildlife Service on 03/15/2019

(31) Paquet P.C. and Carbyn, L.N. (2003) Gray wolf. In Wild Mammals of North America: Biology, Management, and Conservation, ed. Feldhamer, G.A., Thompson, B.C. and Chapman, J.A. 2:482–510. Johns Hopkins University Press


(32) Fascione, N., Lesky, M. and Schrader, G. (2007) Wolves of America: Past, Present and Future. Defenders of Wildlife

(33) Implications for wild land on leaving the European Union, Self-willed land July 2016


(35) Hello, kitty: Two young cats in new area a leap for endangered Florida panther, Jenny Staletovich, Miami Herald 27 March 2017

(36) Florida Panthers: Crossing the Caloosahatchee, The Nature Conservancy

(37) Hannibal, M.E. (2012) Spine of the Continent: The Race to Save America's Last, Best Wilderness. Lyon Press

(38) Ashmole, P. (2019) The meaning of nature conservation – a personal journey. ECOS 40(2), British Association of Nature Conservationists


www.self-willed-land.org.uk  mark.fisher@self-willed-land.org.uk