Clear-Cutting 500,000 Trees in the East Bay Hills, and Other Invasive Species
We had an incredible discussion down at the PLACE for Sustainable Living this past Thursday with Tao Orion, who just wrote a book called Ending The War On Invasive Species. The discussion was particularly relevant and well-attended by folks who are organizing alternatives to an imminent plan by the University of California, the East Bay Regional Parks District, and the City of Oakland to cut nearly half a million trees from our East Bay public lands, in the name of native plant restoration and fire prevention.
The most valuable takeaway that I got from the discussion was that invasive species, categorically, are merely symptoms and indicators of the larger changes and effects of our land use policies, such as agriculture, mining, carbon pollution, logging and urban development. The details are as such:
Every ecosystem seeks to evolve and become more stable over time and eventually reach its climax. Disturbance by humans, other animals, and natural events create more diversity by creating openings for pioneer species into existing ecologies. Invasive species are usually forms of this “pioneer vegetation” that are able to take root in such disturbances.
In a natural course of succession, pioneers die back and yield to and mix with grasses; grasses mix with shrubs and small trees, the small trees grow larger and shade back the grasses and protect the next succession of canopy forest. A healthy climax ecology — where this cycle ends until a major disturbance happens — is relatively unsusceptible to invasive species. The redwood forests of Northern California are a perfect example — a stable, climax forest ecosystem that changes only with dramatic action, such as clear-cutting.
The lot of human activity until now, including annual agriculture, has been based on disturbing this cycle: man disturbs the land by digging and tilling the soil, and we then plant our annual vegetables, which thrive in disturbed soil, just as our invasive species do alongside them. Because of this continued disturbance, the lands where we consistently practice annual agriculture never evolve into more established ecosystems, which is why these lands are intensive in their use of oil and fertilizer and herbicide and insecticides, and are so susceptible to invasive species.
So in this context, a strategy of simply removing invasive species without addressing the systemic presence of soil disturbance is lost labor, as the continuing soil disturbance invites more pioneer invasive plants to thrive. Simply removing invasive species is lost labor. They come back. The caretakers of the land either commit to a losing battle against invasive species, or they must remedy the ways in which the land has been disturbed.
Tao opened Thursday night with the question: “What are we restoring? Why are we restoring it?”
In the age of climate change, is it practical to fetishize “native landscapes”? In the current opportunity in the East Bay Hills, it would be disastrous to cut down mature canopy trees and create a hotter micro-climate in an already warming state. It would be equally neglectful to simply plant our “idea” of a native chaparral woodland— a fire ecology — and expect it to perform without the intervention of fire and/or brush-clearing animals. Rather, it would be better to plant desirable woodland medicinal varieties and to hire the animals to clear brush beneath the existing forest canopy. Much of our land in the West needs this treatment of active care and management.
About a year ago, I started writing a chapter in a larger series of essays on what I was calling “The Permaculture of Seed Without Borders.” I’ll share with you my notes on this subject here:
It is common knowledge that our climate has warmed — simply look at the USDA planting zones on a seed packet today versus those same planting zones from fifty years ago. These zones indicate the ability of certain crops to withstand heat and cold, and show the anthropogenic climate shifts as they are happening. USDA Hardiness Zone 6, for example, has grown northward to take over Kansas, low-lying southern Colorado, Utah and Nevada. Los Angeles and South Florida are now in a new Zone 11, which was not measured anywhere in the continental United States in 1960.
For a zone that no longer has sufficient chilling hours for a certain tree, it would be absolutely appropriate to breed or transplant trees from zones further south (in the northern hemisphere) in order to maintain healthy biomass in a changing climate. It is responsible and necessary to start growing tropical plants in greenhouses in temperate states, and it would be responsible human stewardship of this planet to assist in the shift of ecosystems towards more resilient, more diverse plantings of choice edible foods and diverse ecosystem services.
One of the incredible statistics that Tao reported Thursday evening was that within a century, up to 47% of the land mass in America may be covered by novel ecologies, made up of species which are technically “non-native” to that land, but which are appropriate to the emerging climate regime for that region. This is the response of the ecology to climate change: species migration. The animals will be able to move themselves, but the plants are going to need our support.
In this spirit, Tao is actually growing crops in Oregon from three hardiness zones in either direction — elderberries from Montana and natives from the highlands of New Mexico — and seeing what will work in the emerging and uncertain climate future of her bioregion. It would be wise for people of all regions to begin doing the same, for the benefit of our shared biodiversity.
In essence, the time for a return to “native plants” is gone. The place to plant California natives may be eastern and southern Oregon. California would be better served to import plants from other warm, dry regions (such as Israel or Morocco or even mountainous Southeast Asia) than to attempt to recreate an ecology that would thrive with a cooler climate and active fire-based management, neither of which we can offer.
Humans have the choice of remaining attached to our preconceived idea of what our landscapes should look like, or of accepting the reality of climate change and working to maximize biodiversity, biomass and carbon sequestration in a new climate. The former strategy requires putting in massive effort towards creating park-like landscapes that satisfy our aesthetic desires, but are neither sustainable nor regenerative in the long run; in fact, such efforts may actually backfire by wasting precious energy on landscapes that ultimately fail.
Instead, we can release our idea of what has worked in the past in our local ecologies, and solve for the pattern of what we would love to see in an unfolding, successful, and useful landscape for all species.
Support the Coalition to Defend East Bay Forests on Facebook and spread the word about the half a million trees that are threatened to be felled by UC Berkeley, East Bay Regional Parks District, and the City of Oakland.
Tao Orion’s book, Ending The War On Invasive Species is available from Chelsea Green Publishing.