Rambunctious Garden

The “natural” meandering shape of a stream? Not so much. Researchers in Pennsylvania, the Pacific Northwest, and Europe found that the banked meandering shape we take for granted as the “natural” form of a wild creek is actually a secondary form that appears after a mill dam has been breached.    Before tens of thousands of dams were built for water power in the 1700s, the streams flowed in multiple channels and pools, creating muddy riparian wetlands.   When steam power made the mill dams obsolete, the dams were breached, creating the familiar meandering streams. So, when conservationists seek to daylight and restore a creek to its natural pattern, the meandering form is actually not the “original.”

In Wild Ones, Jon Mooallem is rather angst-ridden about the ambiguities and paradoxes of restoring wild nature.  In Rambunctious Garden, Emma Marris, writer for Nature, celebrates the paradoxes.   The story of the search for the original creek form is one of numerous examples debunking the ideal of a single “baseline” ecosystem that can be restored.  In Hawa’ii, should the baseline be  set before Europeans arrive? Before Polynesians arrive?   In North and South America, Marris cites evidence that native populations had surpassed a hundred million, but the vast majority died of European diseases in the first century after first contact.   Landscapes that Europeans interpreted as empty and wild had actually been full of people and shaped by human activity.   With climate change, the familiar baselines are changing; species’ preferred temperature range is moving north and/or uphill.

After demolishing the ideal of a “baseline” state of nature, Marris reports on science calling into question the importance of the integrity of the “native” ecosystem.  Conventional thinking holds that an ecosystem attacked by invasive species will be less varied and less healthy than a system which maintains all of its original components.  But evidence shows that in many cases newcomers can fit right in, helpfully occupying a niche that has for some reason been left vacant, or complementing the existing ecosystem without displacement.   Even where introduced species are initially destructive, the virulence sometimes decreases, as predators, defenses and infections adapt to the newcomer.

If there is no clear original “state of nature” to restore, and additional species often fit in and don’t cause harm, this opens the door to many more flexible choices of how to protect and enhance the environment.  To cope with climate change, why not help plants and animals migrate? (this was the topic that has Mooallem and the polar bear protectors tied into knots; Marris’ perspective would say move the animals).   To restore a  wetland,  rather than trying to repopulate the original set of species and physical forms, one would identify the functions to be served – cleaning water, blunting floods, hosting fish and birds – and make choices to achieve the goals.

Another area for flexibility is in the landscapes to be considered “natural.” Marris recounts how Americans invented of the ideal of wilderness, citing Nash and Cronon analyzing Thoreau, Emerson, Muir (she outs the Walden Pond refuge as suburban, but omits the snarky detail that Thoreau’s mom came over regularly to do his laundry).  She contrasts the canonical form of Yellowstone and Yosemite, which are intended to preserve pristine wilderness, with park conservation traditions in Europe. An ancient Polish forest has plenty of acknowledged management; there is a long British tradition of protecting wild species in agricultural landscapes.  The book cites a long and ugly history of exiling human inhabitants to create “wilderness” , from John Muir’s exiling Miwok natives from Yosemite, to the removal of native peoples to create wildlife refuges in Africa and South America.

Without a bright line between “natural” human-free landscapes and “artificial” human-cultivated ones, it is easier to see opportunities to improve natural habitat and ecosystem functioning in urban, agricultural, and industrial landscapes, not only in places that are set aside to be free of people.  And hopefully it is easier to take responsibility for the environmental health of populated places, rather than ducking the responsibility because “nature” is being taken care of somewhere else.

If you are “deep green” – if the ideal of untouched wilderness is core to your sense of spirituality and self – and you support environmental organizations so they can protect nature far from cities and suburbs – you will probably not like this book.   If you are interested in the changing science of “restoration ecology” and what it may mean for coping with climate change and protecting biodiversity, you will find this book informative and thought-provoking.

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