#709 The hidden network of nature
The Secret Wisdom of Nature: Trees, Animals, and the Extraordinary Balance of All Living Things — Stories from Science and Observation
by Peter Wohlleben, translated by Jill Billinghurst
Vancouver: Greystone Books/ David Suzuki Institute, 2019
$29.95 / 978177164388
Reviewed by Loys Maingon
Most people are on the world, not in it —
have no conscious sympathy or relationship
to anything about them — undiffused,
separate, and rigidly alone like marbles of
polished stone, touching but separate. — John Muir.
The translations of some books may make one thankful for having sat through several years of German language classes, even decades ago when skies were bluer and a younger man’s heart was outdoors. Peter Wohlleben’s Das geheime Netzwerk der Natur: Wie Bäume Wolken machen und Regenwürmer Wildschweine steuern (2017) was released in March 2019 in Jane Billinghurst’s translation as The Secret Wisdom of Nature. It is the third in Wohlleben’s “The Mysteries of Nature Trilogy,” the second being Das Seelenleben der Tiere (The Hidden life of Animals). In British Columbia, the series draws general popular enthusiasm, as it should, but in scientific circles it sometimes draws unease and irritation. Before discussing this book, it is worth considering why it draws such divergent responses among BC readers.
First, the original German title seems to translate as: The hidden network of nature: How trees make clouds and earthworms guide or control wild boars. Gone is the mystic appeal of the English title, which unfortunately casts a commonsensical author and able presenter as a mystagogue. Gone also, more importantly so in the English title, is a rational child of the German Enlightenment who furthers Alexander von Humboldt’s celebration of the marvellous web of life. Good science, the most convincing science, still rests on the pragmatism of Occam’s razor — “The simplest explanation is the most correct.” In presenting scientific facts, appeals to “mystery” or “magic” generally detract from the appreciation and acceptance of simple facts. In nature writing, they open the writer to suspicion of committing the hoary sin of “nature fakery.” The revised English titles add unnecessary baggage and intellectual barriers to a useful popular ecological primer which, as its original title aptly pointed out, presents a sketch of the complex network connections within the web of life. The complexity of nature is sufficiently marvellous in itself to need no occult or New Age sugarcoating.
Second, the English subtitle of The Secret Wisdom of Nature immediately brings up the hoariest “bête noire” of all boogeymen for biologists and ecologists around the world: the term “the balance of nature,” even when they may tacitly agree with what it is intended to signify. “Balance of nature” conveys a misleading sense that nature exists in, or tends to, a state of equilibrium, and that man is a disrupter who cannot be part of “nature.”
For British Columbians aware of the natural history of our environment, this should cause a number of concerns. We live in a bioregion that is the product of a long succession of geological collisions of terranes from the late Devonian onward. Even though our governments, regional planners, and developers prefer to ignore the fact, we live in an active seismic zone that has a history of massive earthquakes, such as one of 9.2 on the Richter Scale in January 1700. These mega-earthquakes are in the creative habit of re-organizing our landscape about every 250 years. In geological terms, our flora and fauna are punctuated ephemera distributed within constant disturbance processes. We don’t need man to disturb anything: nature does that for its own enjoyment and liberation.
One of the definitive studies on this subject has to be the 2008 work of Robin Waples et al., “Evolutionary history of Pacific salmon in dynamic environments.” It traces the evolution of our iconic Pacific salmon species, whose life cycles are foundational to so much of our flora and fauna, as Wohlleben correctly notes in the second essay of this book, “Salmon in Trees.” Contrary to our mental habits marine environments are not independent of, or really distinct from, terrestrial ecosystems. They are mutually interdependent on the movement of anadromous organisms, and on the biogeochemical processes they share. The foundation for this new awareness came from the ground-setting work of Tom Kline et al. (1990) which alerted the scientific community to the intimate connections between marine and terrestrial environments in the nitrogen cycle. In BC, this important work has been replicated by Dr. Thomas Reimchen and his team at the University of Victoria, who have further demonstrated that the flow of marine nitrogen is not limited to coastal ecosystems but can be found to extend far beyond the Omineca Range in the growth of in montane flora.
This chapter, “Salmon in Trees,” lays out the essential role of salmon in the coastal soil nitrogen cycle and the problematic implications of this finding for the restoration of salmon in a highly urbanized Europe (Thomas Jefferson would have enjoyed this potential riposte to Buffon 200 years after The Notes on the State of Virginia). Waples et al. rightly point out that while the magnitude and intensity of human disturbances over the past two centuries far exceeds any natural disturbances, Pacific salmon are a product of constant disturbances which periodically re-arrange nature’s apparent balance:
In northwestern North America, dominant habitat features have been relatively stable for the past 5000 years, but salmon ecosystems remain dynamic because of disturbance regimes (volcanic eruptions, landslides, wildfires, floods, variations in marine and freshwater productivity) that occur on a variety of temporal and spatial scales. These disturbances both create selective pressures for adaptive responses by salmon and inhibit long-term divergence by periodically extirpating local populations and creating episodic dispersal events that erode emerging differences. Recent anthropogenic changes are replicated pervasively across the landscape and interrupt processes that allow natural habitat recovery.
It is the dynamism of our environment that has paradoxically enabled salmon to diversify and to be resilient to the environmental pressures we place on them. It is our industrial culture’s aberrant excessive need for stasis that engineers and transforms entire landscapes into permanent stable structures (such as canalized rivers and dams) that pose barriers to recovery.
As Waples et al. note, we have been “relatively stable” over the past 5,000 years. It is no coincidence that this period of relative stability also roughly corresponds to the best-documented period of First Nations’ stewardship after the glacial retreat. As has been pointed out before, ecosystems as we know them today around the world are to a large extent a product of the radiation of humans out of Africa. The Serengeti and the Australian outback are products of aboriginal and bushman “fire-stick farming.” Many grasslands — essential to human culture — that we take for granted are in fact “cultural ecosystems.” Recent analysis of ice-core climate data, archaeological evidence, and ancient pollen samples suggests that neolithic deforestation and agriculture 7,000 years ago slowed a natural cooling process of the global climate. It was that same human activity that produced the relatively warmer climate and the resulting ecosystems distribution that we experience today. These are the landscapes that we consider to be a “balanced nature” and the associated “healthy ecosystems” that provide the ecosystemic services we take for granted.
BC is no exception. As did other interior First Nations before the 1930s imposition of provincial forest burning regulations, pre-contact Okanagan First Nations appointed “fire-keepers” who were responsible for setting and managing controlled forest underbrush fires and maintaining berry crops, long before industrial forestry understood the need to control the build-up of fuel that sustains today’s uncontrollable forest fires. Coastal Garry Oak prairies, which are now the most threatened ecosystems, and interior grasslands and forests were maintained for millennia by First Nations “fire-keepers.” Many of BC’s most-cherished ecosystems are the product of culturally-maintained ecosystems. Similarly, as we now watch the Salish Sea ecosystem and old-growth forests collapse with the demise of herring around the Salish Sea, we should realize that all Coastal forests are also “cultural ecosystems.”
North America was neither uninhabited nor terra incognita. First Nations understood the close relationship between the productivity of the forests and that of the marine environment. They understood that herring is the keystone fish that sustained abundant salmon populations, and that coastal Douglas fir, cedar, and hemlock forests and wetland systems were essential to herring and salmon around the Salish Sea. That knowledge rested on the understanding that humans had stewardship obligations to their animal and floral kin in a precarious dynamic environment. Inasmuch as First Nations exercised stewardship, they introduced a cultural balance within a dynamic nature that made all their territories “cultural ecosystems.” The “balance” lies not so much in nature itself, as Wohlleben too often wishes, as in human culture.
To fail to understand that First Nations inhabited and shaped a cultural space — as did other humans around the planet — would be to repeat the colonialist misinterpretation of First Nations as “noble savages,” uncultured and inhabiting an “untamed wilderness” (should we adapt the national anthem to read “a true north, wild and savage?”). There is wilderness where the human animal recognizes and respects the otherness of a living planet and assumes its responsibilities within the web of life. What maintained “wilderness,” in pre-contact North America and after, has been the respectful cultural understanding of the space shared with the land as a living organism, rather than as a larder to be pillaged under the guise of “scientific management.”
The thesis of Wohlleben’s The Secret Wisdom of Nature (which I will refer to as his Book 3) is expressed at the end of the book in a simple sentence: “Wouldn’t it be nice if, at least in protected areas, we allowed nature to take the helm?” (p. 227). The sentiment expressed in this sentence could be completely misread if the reader does not take time to appreciate the plurality of the contexts from which it comes, especially in light of Wohlleben’s too frequent and perhaps romantic insistence on the destructiveness of mankind.
This is almost the closing statement of a trilogy. It makes sense only if we understand it to be a conclusion reached as a logical progression from the first two books. Book 1, The Hidden Life of Trees: What They Feel, How They Communicate — Discoveries from a Secret World (2015), which I also wrote about for The Ormsby Review, is a presentation of the forest as a sentient superorganism, in keeping with the scientific tradition of Alexander von Humboldt and its modern scientific re-interpretation in the forestry and plant behavioural work of Dr. Suzanne Simard and Dr. Monica Gagliano. Book 2 — The Inner Life of Animals: Love, Grief, and Compassion: Surprising Observations of a Hidden World (2016) — is less provocative for the reader because it has been over fifty years since Konrad Lorenz provided a popular introduction to ethology and John Cunnigham Lilly shocked the world by popularizing cetacean and animal intelligence research, which is now commonly accepted. We now recognize that the world is a phenomenon that is experienced differently — and with equal validity – both by many different human cultures and by many species who are our evolutionary kin, and not so different in DNA. As The Cambridge Declaration on Consciousness (2012) notes, the physiological processes associated with consciousness in humans can be found in many other creatures, including insects and molluscs. The physiological processes necessary for consciousness do not require the presence of a specialized neocortex.
As in the case that he built for plant sentience, Wohlleben’s observations and arguments for the consciousness of animals are backed by decades of sound research, which he references. Problems arise in his personal inferences and speculation which sometimes seem to be at odds with reality (for example, as reports multiply expressing concern for the “ruinous overcrowding” of US national parks to the point that some have had to be closed, Wohlleben may be a rare witness to national parks as a “vast landscape devoid of people” (p. 205) and an unspoiled wilderness. This is in sharp contrast to Jon Waterman’s report in the same location: “At Arches National Park, I watched as tourists blithely walked off trail across the desert, destroying fragile cryptobiotic soils.”). A European sense of population density and wilderness can be very different from North American expectations!
This third book, which should have retained its German title, The Hidden Network of Nature, is the logical bringing together of the network connections between plants and animals and their environment, based on what is really commonly accepted behavioural research. So the first context of “letting nature take the helm” is about rebuilding an awareness of many connections between organisms and their habitat in a sentient universe and learning not to impose our modern human priorities. It is about learning to respect the otherness that makes up a vanishing wilderness of which we are just a very small part, and out of which we came and are still dependent on.
Although Book 2 is about our kinship with animals, it establishes the framework of Wohlleben’s experience to be “the European experience,” and sets the stage for his concerns for the loss of Germany’s ancient woodlands in Book 3. It covers some wild animals such as wild boars, squirrels, hedgehogs, and brown bears, but most of the animal observations that Wohlleben makes are from his Rhineland forest home and courtyard: mice, weevils, dogs, horses, goats, rabbits, and crows. The domesticated and semi-domestic farmyard animals are a bridge back to native wilderness. In this respect, the stories arise from Wohlleben’s European context in which nature has been extensively semi-domesticated and subjected to industrial exploitation. So the context of the trilogy becomes a plea to de-industrialize forests and to cease turning all wilderness into a “working forest,” a European problem that has now become a global plague.
Wohlleben’s plea to protect native species and native landscapes from postwar industrialization has global implications. That is where he levels one of his most important criticisms of the current contradictions of conservation practices that set aside conservation or “leave strips” while continuing to legitimize excessive exploitation:
If you think that goes without saying, just take a look in the filing cabinets of conservation areas and national parks. They are stuffed with maintenance and development plans that are far too eager to put sawmills, chain saws, and heavy machinery to work. In the end such plans are neither aesthetically appealing nor ecologically beneficial…. We’ve already seen that most attempts at fixing things come to nothing, so why not simply trust that mechanisms that are millions of years old can still function without us? (p. 227).
Wohlleben’s criticism is quite applicable to Europe where centuries of intensive manual agriculture and the associated proportionally high population at eighteenth and nineteenth-century densities have had a high impact on wilderness areas and connectivity. The human population densities and agricultural demands led to high losses in native keystone species, such as wildcats, wolves, and beavers, first in Europe and subsequently in North America. European forests and wildernesses are therefore impoverished environments, in which the last remaining ancient forests, such as Poland’s Białowieża Forest, which is Europe’s last old growth and a UNESCO heritage site, are under constant threat of clearcutting. “Working forests,” tree and pulp plantations by another name, should not masquerade as conservation areas and “green” spaces any longer. As United Nations concerns with the climate emergency and the biodiversity emergency continue to grow in urgency, preservation and conservation can no longer be an afterthought. Globally, restoration needs to become the guiding priority — as recognized by the UN in its declaration — and the coming decade, 2021-2030, needs to be “The decade of restoration.” That is why Wohlleben’s Book 3 is a particularly important public outreach in the global restoration effort. But it raises legitimate questions about how we intend to restore.
In its European context, Wohlleben’s call is therefore not a simple call to just let “nature” run rampant, weeds and all, and let millennial processes take over. It is a call to respect a living nature and foster its “re-wilding,” that is, its return to what he interprets as a “balanced state of nature,” but which most restoration ecologists would take to be a previous more complex state at a determined anterior point in time. The well-intentioned assumption that Wohlleben and many non-professionals make is that, if keystone native species are re-introduced into severely disrupted and simplified environments, somehow everything will fall back into place and undo the damage. That is questionable, however much we might all desire it.
The introductory essay in Book 3 attempts to make that case for “re-wilding” using the re-introduction of seventeen grey wolves to Yellowstone in 1996. As Wohlleben correctly notes, the story of the re-introduction of wolves to Yellowstone and the trophic cascade that ensued is one of the most celebrated ecological experiments in ecological history. As per Wohlleben’s account, initially it was thought that the wolf re-introduction altered the behaviour of the elk so that streamside willows could re-grow and restore regional hydrological patterns and riparian processes. As pointed out by the University of Alberta’s Mark Boyce, who has been doing research in Yellowstone since 1977, “it is one of the most significant advances in conservation this century.”
However, because this experiment has no replicate or controls, it is difficult to interpret the results, particularly as there are several confounding factors, such as unexpected periods of drought and fires, the absence of beaver and their re-introduction, the unforeseen numerical crash in the elk population, and the dynamics between elk and bison, which also altered ecosystem interactions. As Kirstin Marshall’s research showed in 2013, once damage has occurred, repairs are not as simple to bring about as the return of an apex predator. The loss of beaver caused long-term changes to regional hydrology that prevent the long-term return of willows in many places. Even if the wolf and the beaver are re-introduced after the fact, “the complexity of ecological damage caused by the eradication of a key predator species requires careful consideration of dynamic variables for restoration so additional caution must be emphasized to avoid predator removal in the first place.” So, while Wohlleben somewhat too enthusiastically embraces the successes of this re-wilding experiment, the restoration ecologists who work on the Yellowstone experiment take a much more tempered approach to the noted successes of their experiment.
Similarly, as shown by the difficulties that have plagued, and continue to baffle, the conservation and restoration of Canadian caribou habitat after the impacts of oil and gas exploration, once a major landscape level disturbance is introduced it its difficult, if not impossible, to return to pre-disturbance conditions. Our human decisions and actions have consequences that may not always be reversible. Restoration is often more of a visual illusion than a functional reality. Boyce points out that while re-wilding has been a success at Yellowstone, “it is not clear that trophic cascades will occur in other areas. We cannot be confident that these observations have conservation implications for wolf management and ecosystem restoration elsewhere.”
Human decisions come with long-term responsibilities. Ecosystems do not simply change. They have to re-organize or collapse and re-assemble following major disturbances. The more complex they are, the more difficult it is to re-organize back to a previous state or equilibrium. As the climate change impact axiom goes: “Species move, but ecosystems collapse.” Where Wohlleben is right — and why his avuncular narratives are an important public communication of ecological science — is in his cautionary conclusion that reconciles with Dr. Kirstin Marshall’s conclusion quoted above: “The deeper the realization that even the smallest disturbance can lead to unpredictable changes, the stronger are the arguments in favour of protecting larger areas” (p. 9). The problem that ensues from this is, what do we humans do after we preserve a site? There remains an obligation to long-term stewardship. This is not the same as an obligation to preserve “resources” for our unique benefit. It is the obligation we have to our genetic kin within the “web of life” of which we are part, as the successors of Alexander von Humboldt have struggled to remind us, for two centuries.
Paradoxically, any “balance” that follows from the environmental destruction that our utilitarian industrial society has wrought upon this planet, requires the intervention of mankind. To understand what Wohlleben is really concerned about one has to consider the extent to which the environment has been re-engineered in Europe. In his discussions, Wohlleben rightly embarks on extensive discussions about the evolution and transformation of modern German and European forests from the neolithic period onward to highlight the extent to which the landscape has been transformed for utilitarian purposes. It is a well-founded global concern with important cautionary implications for Canadian readers.
The United Nations, as the European Union before it, is now calling for the urgent planting of billions of trees for the strictly utilitarian purpose of “capturing carbon dioxide.” However meritorious this may seem, the utilitarian planting of trees — as opposed to the maintenance and restoration of ecosystems and existing forests, has a disastrous environmental track record. This makes Wohlleben’s position easier to understand. In both the EU drive to indiscriminately reforest Ireland and Scotland, and in the Canadian drive to plant boreal black spruce commercial forests in northern Alberta and Saskatchewan to increase forestry revenue, rich peat bogs and so-called “marginal soils” were drained, causing extensive damage to endangered species and turning carbon sinks into carbon releases. In the Canadian case this was one of the drivers of the Fort McMurray fires. In the recently-reported Scottish case, characteristic of Europe, important conservation areas of a unique domed bog in the Flow Country were drained and destroyed to plant trees. The Flow Country bogs were re-acquired by the Royal Society for the Protection of Birds (RSPB) and the Nature Conservancy Council, which are now actively engaged in the stewardship and restoration of these peatlands.
These examples, which are symptomatic of a pan-arctic loss of 75 percent of wetlands to agricultural and forestry drainage, make one very important point. Nature does not “repair itself.” While it is humans who initially destroyed these ecosystems for utilitarian purposes, it is also humans who have been engaged for the past sixteen years in the repair of damage done to nature. And notably the scientists who are repairing nature do not see these bogs as just an assemblage of organisms, but as an organism in itself. As the Flow Country lead scientist Dr. Richard Lindsay notes, “If you cut an artery in your leg, it’s a small wound but can have profound effects on you. In the same way, cutting a small part of a bog can have profound impacts because its entire hydrology is connected.” It is this cultural shift that creates the balance of nature, for which Wohlleben has become a commonsensical advocate.
Wohlleben presents delightful peripatetic discussions of a host of surprising ecological connections, including the role of salmon in forest nitrogen ecology; the problem of the ageing of European forests and soil losses; the production of terpenes by trees to control microclimates; the relationship between scotch broom, ticks and deer; the dependency of rare fly species on old growth; and how earthworms carry lungworm and thereby control wild boar. But that is really just a vehicle to convey to his readers that forest systems are self-organized superorganisms and that they are extremely fragile, irreplaceable, and essential to our human wellbeing. That runs counter to the dubious government claims of creating biodiverse green spaces in commercial forests (p. 148), or the artificial overstocking of game in German forests (p. 131). All of which work to present counter arguments to utilitarian forest management, which has guided North American forestry since the appointment of Gifford Pinchot as Secretary of the Interior by President Theodore Roosevelt in 1905, and therefore also has tremendous application to BC’s long history of forest mismanagement.
Chapter 14 is aptly entitled “Our Role in Nature.” As we enter an era of ecological tipping points, this may be one of the most important considerations in this trilogy. The problems Wohlleben poses are once again very Eurocentric, as when he notes that “98 percent of the forested areas in Germany are planted, cared for, and harvested on an industrial scale…” (p. 190). Readers should consider that the quilt-work of clearcuts that characterize BC’s forests today are driven by the same mindset and headed in the same direction.
In his last chapters, Wohlleben wrestles with the tensions between culture and nature — often contradictorily so, because he is caught between pessimistic interpretations of post-glacial neolithic extinction of megafauna, the extent to which it shaped the resulting floral composition of European forests, and the contrast with the “intact” apparently pristine Amazon forest. His subsequent realization in the last pages of the book that the discovery of 450 geoglyphs in the Brazilian forests of the State of Acre also reveals to him that aboriginal peoples sustainably maintained “a system of forest management spanning thousands of years” (p. 230). This revelation once again brings to his and the reader’s attention the fact that the European utilitarian experience does not necessarily constitute an inescapable ecological destiny.
Globally, mankind can live in partnership with wilderness only if we can make a cultural shift. It is sometimes difficult for readers who may not be fully aware of the extent to which our industrial culture is eliminating wilderness and even bringing civilization to the brink of disaster, as David Attenbrough has so eloquently pointed out, to realize that Wohlleben’s chatty popular essays are one of the most important contributions to changing our cultural outlook and balance. By pointing out the sometimes strange connections between species he reconnects his readers to the living environment about them. In the scientific tradition of von Humboldt, he unabashedly calls on us to recognize the importance of emotion in science communication, and so opens the door to the “transformative change” that The Intergovernmental Panel on Climate Change urges us to make. Rightly so, as Wohlleben notes (p. 125): “Empathy is one of the strongest forces in conservation, and can achieve more than any number of rules and regulations.”
A graduate of the universities of St. Andrews, UBC, and Saskatchewan, Dr. Loys Maingon first taught environmental studies in 1986. An avid naturalist and a registered professional biologist, he is past president of the Comox Valley Naturalists and current webinar host for the Canadian Society of Environmental Biologists. From his home on the Tsolum River near Merville, he owns and operates an endangered plant nursery and oversees a number of regional conservation and heritage programmes. He is also Research Director of the Strathcona Wilderness Institute and does environmental consulting. Arrested at Clayoquot Sound in 1993, Loys remains a strong advocate for social, economic, and environmental change. He contributed a chapter to Clayoquot & Dissent (Ronsdale Press: 1994).
The Ormsby Review. More Books. More Reviews. More Often.
Publisher and Editor: Richard Mackie
The Ormsby Review is a journal service for serious coverage of B.C. books and authors, hosted by Simon Fraser University. The Advisory Board consists of Jean Barman, Robin Fisher, Cole Harris, Wade Davis, Hugh Johnston, Patricia Roy, David Stouck, and Graeme Wynn. Scholarly Patron: SFU Graduate Liberal Studies. Honorary Patron: Yosef Wosk. Provincial Government Patron since September 2018: Creative BC
“Only connect.” – E.M. Forster
 Robin S. Waples, George S. Press and Tim Beechie (2008) Evolutionary history of Pacific salmon in dynamic environments. Ecological Applications 1:189-206.
 Before the current republican governor of Alaska removed environmental research funding to push for the controversial clear-cutting of the Tongass forest and mining at Bristol Bay, the University of Alaska was a leader in Pacific climate and ecological research. In 1990, our understanding of the complexity of the web of life received a landmark revelation when research into salmon-derived nitrogen inputs to the coastal forests and ecosystems was first undertaken in Alaska’s Bristol Bay, which persuaded the Alaskan government to protect Bristol Bay and the Tongass forest. See Kline,T.C., Jr., J.J.Goering, O.A. Mathisen, P.H. Poe, and P.L. Parker. 1990. Recycling of elements transported up-stream by runs of Pacific salmon: evidence in Sashin Creek, southeastern Alaska. Canadian Journal of Fisheries and Aquatic Sciences 47:136-144; Kline, T. C., Jr., J.J. Goering, O.A. Mathisen, P. H. Poe, P. L. Parker, and R. S. Scanlan. 1993. Recycling of elements transported upstream by runs of Pacific salmon: evidence in the Kvichak river watershed, Bristol Bay, southwestern Alaska. Canadian Journal of Fisheries and Aquatic Sciences 50:2350-2365.). A more subtle understanding of the flow of nitrogen in freshwaters was brought by Wipfli et al. in 1998 (Wipfli, M. S., J. Hudson, and J. Caouette. 1998. Influence of salmon carcasses on stream productivity: response of bio- film and benthic macroinvertebrates in southeastern Alaska, U.S.A. Canadian Journal of Fisheries and Aquatic Sciences 55:1503-1511.) In Canada, Dr. Thomas Reimchen’s lab at the University of Victoria pioneered similar work in BC, in the watersheds of Warn Bay, Bulson, Moyeha, Megin, Watta, and Sidney, and have since expanded our knowledge of
the flow of marine nitrogen throughout the province’s ecoregions. (Wilkinson, C. E., M. H. Hocking, T. E. Reimchen. 2005. Uptake of salmon-derived nitrogen by mosses and liverworts in Coastal British Columbia. Oikos 108: 85-98; Reimchen, T. E, D. Mathewson, M. D. Hocking, J. Moran and D. Harris. 2003. Isotopic evidence for enrichment of salmon-derived nutrients in vegetation, soil and insects in riparian zones in coastal British Columbia. American Fisheries Society Symposium 34: 59-69; Mathewson, D., M.H. Hocking, and T. E. Reimchen. 2003. Nitrogen uptake in riparian plant communities across a sharp ecological boundary of salmon density. BioMedCentral Ecology 2003:4.)
 Waples, Press and Beechie, op. cit.
 https://phys.org/news/2016-01-mounting-evidence-early-agriculture-staved.html; William F.D. Ruddiman (2003). “The Anthropogenic Greenhouse Era Began Thousands of Years Ago,” Climatic Change 61: 261–293.
 https://vancouversun.com/news/staff-blogs/health-of-fishery-based-on-assessment-of-a-broken-ecosystem-sfu-study-finds; Loys Maingon (2019). Narrowing Choices in an Ecological Collapse. Bulletin of the Canadian Society of Environmental Biologists.76:7-11.
 Nancy J. Turner, Douglas Deur and Dana Lepofsky. (2013). “Plant Management Systems of British Columbia’s First Peoples,” BC Studies. 179:107-133.
 https://www.youtube.com/watch?v=Un2yBgIAxYs ; https://www.youtube.com/watch?v=dRSPy3ZwpBk ; https://www.researchgate.net/profile/Monica_Gagliano; (2018) Thus Spoke the Plant. Berkeley: North Atlantic Books. 162 pages.
 http://fcmconference.org/img/CambridgeDeclarationOnConsciousness.pdf; http://www.animalcognition.org/2015/03/25/the-declaration-of-nonhuman-animal-conciousness/
 Mark S. Boyce (2018) “Wolves for Yellowstone: dynamics in time and space.” Journal of Mammology, 99(5):1021-1031.
 https://phys.org/news/2013-02-wolves-impact-yellowstone-ecosystems.html; Kirstin N Marshall et all (2013). “Stream hydrology limits recovery of riparian ecosystems after wolf reintroduction”. Proceedings of the Royal Society. https://doi.org/10.1098/rspb.2012.2977
 See Terry L. Root and Stephen H. Schneider (2002). Wildlife Responses to Climate Change: North American Case Studies. Island Press.
 Aaron Sachs (2006) The Humboldt Current: Nineteenth-century Exploration and the Roots of American Environmentalism. Penguin.
 https://www.theguardian.com/environment/2019/nov/27/scotlands-peat-bogs-reveal-their-secret-strength-carbon aoe?CMP=share_btn_fb&fbclid=IwAR0ab9a8wfxRMHcd_l0MueY91vVnXiWSICqhp9ScT_7pTh1DJreVqaA7CLA