Equilibrium Part 1 - Virtuous and Vicious Cycles in Ecology
How ecosystems move from more to less productive, or less to more productive.
I'm a real sucker for analogies to life from ecology. There are a few characteristics of ecology that map really well onto my observations about our own individual lives, our culture, the incentives that drive us, and the complex systems we weave and disrupt. That's why I want to start with two examples from ecology of the transitions from one equilibrium to another to say something broader about life. This transition disturbed what was once a balanced spinning, to an accelerating, cascading, self-perpetuating disturbance, to a return to balanced motion at a different plane or level of productivity. It could be a higher or lower plane!
The first is the process of desertification. Hidden in that uncommon word is 'desert' -- an arid, sandy, relatively less diverse ecosystem. Deserts occur when the conditions to create them and sustain them are right. And humans create those conditions, often unwittingly, by the way we modify a landscape to suit our needs. Sometimes, desertification happens when we remove vegetation. Most places where it was otherwise suitable would be heavily wooded or thick with vegetation without our intervention, but scrub and forest are very inconvenient impediments to growing crops and grazing cattle. Thus it must go. This act of intervention may seem straightforward. Indeed, it is replaced by other activities that could plausibly be naturally occurring -- after all, don't ungulates graze wild? Don't food-producing plants grow in natural environments?
But nevertheless, this process too often sets off a chain reaction, a downward spiral, toward ecological catastrophe. Overgrazing by cattle or the seasonal turning of soil lets wind and storms blow or leach away rich topsoil that has in many cases taken hundreds or thousands of years to build up. The impoverishment of the soil then makes it more difficult for plants to root in and maintain hold of what topsoil remains. Then the composition of the soil changes, as finer particles are lost and leave behind only larger-grained sands and as the contributions of roots and nitrogen fixing plants to soil quality are lost. Groundwater drains more quickly, drying out the soil. Even the weather shifts subtly, as there are fewer surfaces for condensation and evaporation to swell the clouds and bring the rains. This downward spiral has its own inertia, each revolution providing enough force for the ecosystem to take its next downward step.
Deserts are fascinating ecosystems in their own right. An incredible and resilient set of species eke out a living in the hardscrabble, wicking what little moisture and extracting what few nutrients exist to hold their place in the order. But they are far less productive, both for themselves and for us. I mean productive in basically every sense. Desert-adapted organisms are far more efficient with their resources, which means that they do more with less, but even more truly, they do less. Expending energy wantonly in the desert is a recipe for death. So too do deserts contribute relatively less to ecosystem services, the anodyne term we use to describe the life-sustaining processes that provide us clean water to drink, oxygenated air to breath, pollinated plants to grow and eat, and so on.
There are places in this world that, at this moment, almost cannot help but be deserts. A brutal morphological and climatological determinism yields little rain and hot sun in certain areas, and over time, deserts arise or, more precisely, are uncovered. Deserts have their own intricate and sustainable internal logic; entire species groups which are adapted to the shifting sands, the dramatic fluctuation in temperature, the extreme unavailability of moisture and forage, and the relative lack of habitat. This is a balance which reproduces itself, with a careful coordination between producers and primary, secondary, and even tertiary consumers. This coordination is, of course, blind: its main mechanism is starvation and extinction. So the balance it sustains is not one of stasis, of a freezing in place. It is a balance of perpetual swings and movements, of dips that yield a rise, of jumps that lose steam and precipitate a fall. In other words, an equilibrium that is dynamic, pulsating, always seeking but never finding the center. Store this equilibristic dynamism for later; I'm not really here to talk about deserts!
Despite the rugged beauty, the extraordinary extremes of survivalism on display, why on earth would we stand for landscapes of these types arising in places they don’t need to, and by the effort of our own hands? Desertification and the intermediate steps preceding it are well-known and much-worried-about ecological downshiftings that threaten our air, food, and water. The deserts or desert-like conditions they could yield would equilibrate and maintain themselves, once they had reached a loop on the spiral they could bounce back from. Old species, ill-adapted, would die out. Sufficiently hardy species would select for nutrient and moisture poverty and survive. New, drought-tolerant and efficient species would move in. And life would go on. The young would be born, live, die, and sometimes manage to reproduce before they do so. But if the land had memory, it might recall the days of plenty, the happy abundant days of water and nutrients, of dense canopies and thick topsoils. Or were it some kind of ecological accountant, it would recall a high density of flora, a staggering diversity of species per acre, a large quantity of stormwater processed to groundwater in its marshes and gullies, some great volume of oxygen exhaled by its plants, a great quantity of carbon bound in its fibers. In other words, deserts flourish in their own right, but the landscapes they replaced would have produced more. The world will not be the same.
One final note bears mentioning: in many cases, the landscape a desert was before it was pushed down and around the spiral may never return. Without an abundance of early-succession grasses to fix the soil, to provide habitat for the insects and worms so vital to soil health, to die and decay and return their own nutrients to the soil, the next potential stage of succession will never have appropriate soil to spring up in. Not only will the next stage of a succession never take off, will never start the flywheel spinning upward, but the few random times of plenty a desert experiences will simply be wasted. Deserts experience torrential rains at times, but what is it to do with all that water? It cannot slow it down. It cannot capture it on the ground, distribute it to layers in the soil where it is needed, capitalize on its sudden appearance to make sustainable gains. What opportunistic vegetation springs up will be baked out of existence almost immediately once the water is sucked inexorably through the wide crystalline grains of sand into the deep aquifer below. The only lasting legacy will be the wild fluvial etchings it leaves behind. Even when given the proper resources and conditions, it is difficult to rise out of a lower-order equilibrium once a complex system like an ecosystem is there.
The second ecological story of equilibrium is that of polyculture. Generally, polyculture is the practice of planting multiple crops in the same location. Polyculture is a form of agriculture often used by those attempting to restore lost conditions of biodiversity, soil health, and ecosystem services to a blighted landscape. It proceeds both from the rediscovery of indigenous agricultural practices and the rather straightforward observation that species of flora and fauna do not seek neat, orderly, homogenous rows of themselves but thrive in a series of mutualistic patterns and groupings.
A complex web of interdependencies, many of them still opaque to even the most dedicated student, are at least partially determinative of a species' reproductive success. Insects, fungi, and bacteria busily process decomposing matter, slowly accreting rich nutrients in the soil, uptaken by pioneer plants whose hardy composition and web of roots fix the soil and provide habitat for small creatures and other species of insect and fungi whose silent work yields benefits to yet other, higher-order species. Many valued species of plants actually take shelter in the broader, higher canopy provided by taller and hardier plants. An ecosystem thus constituted can support flora and fauna who thrive in sun and shade, wet and dry, alternately competing against and cooperating with each other for a distribution of the spoils.
In our infinite hubris and desperate hunger, we saw these apex species -- calorie-dense fruits, roots, legumes and protein-dense animals -- and sought to make them, and only them, successful in our landscapes. Kneecapping their elaborate and indirect support structure while developing intensive schemes of management and control to maintain the unsustainable yield expectations their temporary success set is bound for failure. It is the futility of this arms race between nature and technology that has induced the reaction to industrial forms of food production that polyculture, and permaculture more broadly, represents. And it ought to reconfigure our concept of nature: from a series of limitations that we must overcome to a set of processes that we can support and amplify both for our and its good.
What is hopeful about the story of polyculture is that it casts human management and cultivation of landscapes as possibly net-positive interventions. We too often forget that we, too, are organisms in a vast interdependent web, and that our intellectual and physical capacity gives us both the opportunity and the duty to bend these landscapes to our use. But the mode of that use is so extraordinarily important. A short-termist and extractive approach to agriculture provides high yields but high destruction. An approach that both situates humans within this interdependent web and reminds us that we are only one more generation of a species that will, we hope, continue into the distant future, requires us to think both about cultivating toward productivity and building toward sustainability. An agriculture that builds soil, the nutrients of which will only be taken up and consumed by our great-great-grandchildren, is one which distinguishes this form of agriculture as profoundly human.
What I mean by all of this is that a productive and rich natural ecosystem can be 'perturbed' into an upward spiral of ever-richer growth until it stabilizes at a new, and higher, equilibrium. The cautionary tale of desertification might well be that productive human intervention is a contradiction in terms. But the hopeful story of polyculture is that it need not be. Modifying the distribution of species, introducing new ones, and weeding out others can either nudge an ecosystem into downward or upward spirals into blight or verdure. But what distinguishes a productive from a destructive intervention? That is our next concern.