The Pathology of Disturbance
If I may start with a sweeping truism, we tend to fear change. At the core of this is a resistance to what we do not understand, what is unfamiliar. And yet, life is change. It is the only constant. I was struck this week by a quote from The Parable Of The Sower by Octavia Butler, relayed by the incomparable Adrienne Maree Brown.
“All that you touch You Change. All that you Change Changes you. The only lasting truth Is Change. God Is Change.”
Good right? When run through the lens of ecology, it rings true for every component of an ecosystem- from the ruminant, to the grass to the microbe. Why should we be any different?
However, the central narrative of conservation flies in the face of this truth. It says that the best thing we can do is cordon off a place and leave it undisturbed by our impact, which, in this paradigm, can only be negative. So long as we abstain from impacting this area through our interactions with the landscape, then whatever exists outside of its confines is fair game for our presumed inherent destructive tendencies. (see my first blog post for more on this) Part of this is related to our aversion to change, which is to say our attachment to things as they are. This is however, only half of the story. Western culture, wellspring of the anthropocene, does not so much fear change, as it fears that which it cannot control. It does not seek to eliminate disturbance, but rather to be the sole agents of it.
In ecology, disturbance denotes a distinct phenomenon that brings about significant change to the entities that compose an ecosystem, with regards to their function, morphology, and distribution. Basically, something that happens that changes everything. The scale of the disturbance correlates with the amount of change it brings about. But its frequency has an inverse relationship to that amount of change. For example, the regular grazing, nutrient depositing, and trampling of wild migratory ruminants in a grassland often takes place on an annual or biennial basis. Fire regimes vary widely depending on climate and vegetation community, but can happen naturally on a five to fifty year cycle. Earthquakes, hurricanes, even volcanic eruptions all constitute disturbance events as well. Importantly, the less frequent, and consistent these disturbances are, the less evolutionary pressure they place on the organisms that inhabit the landscapes they affect, and hence the less adapted these organisms are to respond positively to these disturbance events.
To understand what good disturbance is with regards to type, frequency, and intensity, in any given landscape, a good deal of detective work is required. By looking at historical records, scientific data, and traditional Indigenous knowledge, it is possible to gain a window into the disturbance regimes that shaped the flora and fauna of California. Specifically, the disturbance regimes of fire, flood, and herbivory are fascinating and critical lenses through which to view the staggering amount of biodiversity and number of endemic species of the California floristic province.
Looking back at California flora before the Pleistocene extinction, we can see that an impressive cast of characters coevolved with its grasslands and savannas; ecosystems which, when combined, once constituted nearly a quarter of the land in the state. “Megaherbivores” like Camelids, Bison, horses, Giant Ground Sloths, and Mammoths, all migrated through a sort of “California Serengeti”, pursued by now extinct predators like the Short Faced Bear, Saber Toothed Tiger, and Dire Wolf. In fact, some of our only direct evidence of Pleistocene grassland communities come from plant remains caught in the molars of herbivores at the Rancho La Brea tar pits in Los Angeles; among them bromes, fescues, grama grass, galleta, and dropseed. Though these megafauna all went extinct 10,000 years ago, a mere blink on the evolutionary timescale, and the disturbance regime they created is a significant force that shaped the species we encounter today. In their absence there is much debate as to how these disturbance regimes changed, but undoubtedly surviving herbivores and predators took up the Pleistocene mantle. Laura Cunningham, in her book A State of Change: Forgotten Landscapes of California asserts that “In pre-contact grasslands the herds of Tule Elk were unrestricted by fence and probably wandered long distances, erratically in search of the greenest pastures, traveling to water sources and mineral licks, herded by wolves. Local grass ranges were given rest periods--a natural form of complex deferred rotational grazing.”1
And then europeans arrived and fucked the whole thing up. (A sentence which may be the single best historical summary of the last 500 years I can think of). Through the introduction of Mediterranean invasive grasses, the unsustainable market hunting of wild herbivores, the extermination of predators, and the genocide of Native peoples, they all but destroyed this ancient disturbance regime and replaced it with something they could control. They set loose hundreds of thousands of sheep and cattle, to graze on the newly empty grasslands. With the presence of fences restricting their movement, and the absence of predators to affect their grazing behavior, these animals spread out and ate everything down to the dirt. In other words they created a novel pattern of disturbance, the frequency of which was orders of magnitude greater than that under which these grasses, wildflowers and trees had evolved. The result has been the relegation of the vast majority of California's native grassland species, especially bunch grasses, to small remnant populations. California’s millions of acres of grassland are now dominated almost entirely by a handful of invasive Mediterranean annual grasses, a shadow of the magnificent biodiverse grazing paradise that once existed, and a contender for the most altered and novel grassland ecosystem in the United States.
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The coevolutionary relationship between California flora and fire follows an uncannily similar trajectory. The cadence of fire regimes varied widely in different ecosystems, but from wetlands and grasslands to oak woodlands, to chaparral, to conifer forests, it was integral to almost all of them. Many of these seemingly clearly defined and stable ecologies are only kept in their current states by disturbance regimes. Remove fire and grazers from coastal prairies, and they become inundated with brush; remove fire and grazers from oak savannas, and they become oak woodlands. Remove fire and grazers from oak woodlands, and conifers encroach on them, shading out the robust understory.
In fact, though grazing and fire are distinct disturbance phenomena, the ecological function they fulfill is, if not interchangeable, at least comparable. A nearly tenfold increase in the frequency of wildfires in North America--approximately 12,000 years ago-- tracks quite well with both the extinction of Pleistocene megafauna and the arrival of Native peoples, though the timing of this arrival is heavily contested, both by some archeologists who have found some evidence of Native peoples in the Americas long before this, and by Indigenous cosmologies which claims they have always lived here. There is much debate over whether that extinction was a result of overhunting, climatic shift, or a combination of the two.
Regardless of the cause, the result of this extinction was a disruption of a disturbance regime that had been in place in one form or another for nearly a million years. Suddenly (on evolutionary timescale) there were no Mastodons or Giant Ground Sloths to uproot and clear out saplings, keeping Savannas from becoming forests; the great herds of Bison (20 percent larger than their contemporary relatives) and horses no longer grazed the vast central valley. The result was an excess of vegetation that was not being “cycled” through rumen or combustion. Fires in California lack a consistent combustion source during the dry season, as lightning generally accompanies rain in most of the state. One conclusion that could be drawn based on the increase in wildfires during this period, is that Native peoples witnessed the composition of the ecologies they depended on changing, and took their management into their own hands, replacing the impact of mastication and trampling with that of the fire stick. What we do know for certain, is that Native tribes across California managed fire over vast acreages with a great deal of skill and intentionality, keeping them clear and productive and creating a disturbance regime that reigned for at least ten thousand years.
But with the genocide of Native Californians, colonization by Europeans, and the misguided tyranny of Smokey the Bear, all of that came to an end. Land was divided into smaller and smaller parcels, fires were quickly put out and suppressed, controlled burns by remaining Indigenous peoples were outlawed, and without any natural process to cycle it, the fuel load grew and grew. The result is the wave of catastrophic mega-fires that decimate ecologies instead of cleansing them of dead and decaying materials. Even in a fire-adapted landscape, vegetation cannot survive temperatures which quite literally sterilize the soils, leaving nothing alive in their wake.
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California contains one of the greatest and largest agricultural valleys in the world. It is notable not only for its size and the quality of its soil, but also for its proximity to what once seemed an endless supply of water flowing from the snowpack from the mountains that rise from its eastern edge. In a Mediterranean climate that can go eight months without a drop of rain, the snowmelt from the Sierras which feeds the central valley during ]the spring and summer is nothing short of a miracle. The ecology of the valley since the Sierras rose above it 40 million years ago is defined by this cycle of flooding. This flooding did so much more than irrigate the land; it deposited an immense influx of nutrients across the valley which “gradually soaked into the giant ‘sponge’ of Tule marshes, giving rich silt to the fertile low valley lands.”2 The flora of the valley was distinctly adapted to this seasonal inundation. Cottonwoods would colonize newly formed gravel bars while willows and alders formed thickets along river banks, with floods breaking off and eventually depositing branches which easily rooted and grew new trees when the waters receded. On slightly higher ground, towering Valley oaks tapped into the high water tables and rich soils, able to survive temporary flooding and growing to be the largest oaks in California. Before being logged and cleared for agriculture, the Sacramento River had a wooded Riparian belt four to seven miles wide, all of it dependent on flooding.
The Sutter Buttes (known as Estom Yanim or “Sacred Mountain” by the Nisenan people), a place very dear to my heart which I now call home, is a small volcanic mountain range that sits in the middle of the Sacramento valley, rising in a near perfect circle between the Coast Range and the Sierras. In his book “Inland Island” naturalist Walt Anderson, describes the floods that would inundate the valley in the spring, causing this singular range to become an island in a vast sea. I’ve spent many days sitting on its peaks looking at the valley arrayed before me, chopped up into squares of tilled lifeless soil, glaring green rice paddies, and orderly straight canals, trying to imagine the unbelievable biodiversity that once was here. The Buttes sit directly in the Pacific flyway, one of the greatest migratory bird routes anywhere in the Americas. Early accounts describe the “almost deafening, tumultuous, and confusing noise of the innumerable flocks of geese and ducks which are continually flying to and fro and at times blackening the very heavens with their increasing numbers.”3 The birds still come, but their numbers have dwindled. Now quiet winter days are only occasionally interrupted, by the squawk of ragged V’s of geese, making their way South.
In his book “Battling the Inland Sea” Robert Kelley describes the initial futile attempts to control the annual flooding. With dikes and levees being constructed by burgeoning agricultural towns in the Valley, only to be washed away, along with houses and people. This was a result, not just of heavy seasonal flooding, but of the millions of tons of sediment coming downstream from hydraulic gold mining in the Sierras. But after nearly a hundred years of trial and error, the Sacramento valley contains arguably the largest and most elaborate system of flood control and water distribution in the world, composed of over a thousand miles of levees. Kelley pays brief homage to the tragic environmental outcome that is “the disappearance of all of this natural beauty– one of America's largest freshwater wetlands” in the name of “a chemicals-driven, soils-exploitive corporate agriculture empire that has given us grave ecological problems.”4 But then Kelley quickly backtracks, justifying the shackling of the rivers of this land with the tired excuse of inevitability.
“There are now hundreds of thousands of people living on a million acres of protected land in the valley who could never have taken up residence there were affairs still in their natural condition…. To say that the Sacramento Flood Control Project should never have been brought into being seems beyond any reasonable calculus….”5
(Note the glaring omission of the thousands of Indigenous people displaced and murdered to make way for the “valleys current residents”).
This sentiment seems so indicative of the precise cultural pathology America holds regarding change and disturbance: that our systems of control and domination, while admittedly destructive, and unsustainable, are necessary for our culture to live as it does. This assertion rings true to me, but the conclusion drawn is, amazingly, not that we need to change our way of being, or question the fundamental tenets of domination and control woven throughout our culture, but rather that this is simply the way things are, and the way they must be.
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The core of so much of our ecological dysfunction lies in the disruption of disturbance regimes that the plants and creatures here evolved under. When properly diagnosed as such we can focus on restoring the processes that lead to ecological health and balance, as opposed to simply trying to restore or protect the elements that were a result of these processes. I contend that mimicking historical grazing regimes with our domesticated livestock will do a far better job of supporting and restoring native grasses than planting them one at a time, or removing grazing all together. Bringing back low intensity, Indigenous-led, burning regimes will do far more to protect and revitalize our forests than the massive mobilization of resources and people that constitutes our wildfire fighting force. Taking down dams and levees, restoring rivers to their natural meandering channels, and removing permanent human settlement from floodplains will be far more effective at providing habitat for everything from salmon to egrets to willows, than will creating small artificial wetlands, flooded rice fields, and fish hatcheries.
We are far from enacting any of these disturbance regimes on a scale commensurate with the problems their absence has created. So in the meantime, it may be that elements of the “bandaid” solutions will be necessary during the transition. But when we confuse the two and believe that we can address the root causes with small tweaks to a system of rigid control and domination of natural processes, we put ourselves and the places we love in grave danger.
The solutions I describe require a huge commitment of time, resources and energy. They demand deep ecological knowledge and technical expertise. They require unprecedented shifts in the way we produce food, where we choose to live, and who we look to for guidance. Most of all, they require a more ineffable internal change in the way that we are in this place we long to call home: a letting go, a slowing down, a settling, a listening, an unclenching, a trusting. It requires a commitment to place, to seeing it as it is, grieving what has been lost, and dreaming of what could be. As we liberate the water, fire and flora of this land from the shackles we have placed them in, we also liberate ourselves. When we embrace change as a process we cannot control but only participate in, we see that we are not alone in changing the land, the land will change us too.
Laura Cunningham, A State of Change, Heyday, Berkeley, Ca, 145.
Cunningham, 92
Cunningham, 81.
Robert Kelly, Battling the Inland Sea, University of California Press, Berkeley, Ca, xxii
Kelly, xxiii
I have done a profoundly inadequate job of properly recording where all the information contained in this essay came from. In lieu of proper citation of material not directly quoted, here is a list of books that have informed my thinking on all of this.
A State of Change: Forgotten Landscapes of California, by Laura Cunningham. This books is now out of print, but she has recently uploaded the content to a new website, and it is well worth a read.
Battling the Inland Sea: Floods Public Policy, and the Sacramento Valley, by Robert Kelly
Tending the Wild: Native American Knowledge and the Management of California’s Natural Resources, by M Kat Anderson.
Fire: A Brief History, by Stephen J. Pyne
Savanna: How Modern Problems Were Born Out of Prehistoric Extinctions, by Nate Chisholm.
Inland Island: The Sutter Buttes, by Walt Anderson
Secrets of the Oak Woodlands: Plans and Animals Among California’s Oaks, by Kate Marianchild
Emergent Strategy: Shaping Change, Changing Worlds, by Adrienne Maree Brown