Some things are just a given – until they’re not.  And thanks to author Emma Marris, many of us will never look at the world in quite the same way again.  In her recent book, Rambunctious Garden:  Saving Nature in a Post-Wild World, Marris upends some of the most cherished assumptions in ecology and conservation.   In doing so, she skillfully maneuvers through the immediate resistance her book triggers in long-time conservationists like me.   We don’t want to go there, but Marris takes our hand anyway and walks us carefully through this sensitive journey, each chapter making its case and easing the way for the heresy of the next.  The result is a world transformed and, for conservationists, moorings lost.

Drawing on scientific publications and interviews with ecologists in the fields of invasive species, conservation biology, restoration ecology and more, Marris argues that the magical pre-human (or at least pre-industrial) ecosystems of conservation dreams don’t exist.   That the earth has not only been constantly changing on long geological and short industrial timescales, but that pre-historic people also substantially modified landscapes and killed off whole species.   Nothing, it seems, is pristine and it never was.

This realization isn’t entirely new to conservationists.  But Marris forces the uncomfortable questions it inevitably raises:   If nothing has ever been pristine, then what’s our baseline?  To what state are we conserving or restoring?  If, for example, the extensive American prairie was an artifact of intentional burning by native people (as some believe), then is restoring the prairie ecosystem, even in part, an appropriate conservation goal?  What system would have emerged in the absence of indigenous fires?  Should that ecosystem be our conservation goal?

Conservation convention often draws the line at European, rather than indigenous, influence.  But we now know that the American landscape first recorded by Europeans was not free of their impact.  Smallpox was the first of many alien invaders to come, spreading rapidly across Native American populations that had no direct contact with the Europeans who brought it to their shores.  Because of this, indigenous numbers and cultures declined dramatically before Europeans actually settled.  (You can read discussions of this in the books 1491 by Charles Mann and Guns, Germs and Steel by Jared Diamond.)  Some have even hypothesized that the vast numbers of bison found on the American frontier were merely a reflexive boom of a prey species after its main predator – people – went bust.   Does all this mean that we need to look back 13,000 years for our baseline, to before invasive humans arrived on North America and killed off the mastodons and giant ground sloths?  In fact, some have proposed introducing modern proxies for Pleistocene species to do just that.

Marris pries open this vulnerable crack in the conservation foundation further with additional uncomfortable realities:  Among them, that maintaining the “wildness” of that pre-European ideal takes a heck of a lot of (artificial) human management now.  (She notes for example, that the National Park Service maintains 16 exotic species management teams spread across hundreds of parks to remove exotic species not present when Europeans first arrived.)  That continuing this ideal will require even more heavy-handedness and awkward questions in the future as climate changes. (Do we help species migrate north to new locations, or do we let them sort it out themselves?  Is assisted migration natural?)  That evidence now suggests that ecosystem succession does not progress in an orderly fashion to a fairly stable natural climax state.  (Too many variables – human and otherwise – routinely adjust this process, such that the concept has become meaningless.)  And perhaps most uncomfortably, that ecosystems of co-evolved (read:  not exotic) species actually aren’t uniformly more diverse or more productive than mongrel ecosystems comprised of accidental tourists from all over the world.

Such revelations can trigger both profound and pragmatic reactions among conservationists.   On a profound level, ecological succession to a climax community provided stability and order to the world.  Co-evolution suggested an Eden where everything works.  For decades these principles were considered ground rules that governed the biosphere, and as frail (if numerous) animals dependent on that biosphere, we felt those rules should govern our behavior as well.  On a pragmatic level we fear opening the floodgates:  If someone claims “it’s all good” then what will the bad guys do with that message?   Use it as a handy excuse to degrade ecosystems further?  But what does “degrade” mean now?  Without our guideposts, how do we find our way forward?

Marris takes a very utilitarian approach to the future.  Novel, human-influenced ecosystems of nonnative species can be exceedingly valuable she notes, at times providing habitat for endangered species, protection for soil and shade for vulnerable seedlings among other things.  Instead of fighting the reality of the constantly changing world around us, she urges us to embrace it and find ways to make it work.   In short, to identify what we value in a particular location and manage for those values, whether it’s aesthetics, recreation and native species, or crops, timber and clean water.   There’s no grand plan other than recognizing and maximizing the possibilities in a world now dominated by people.

To a certain extent this is what we do now in practice anyway, and letting go of the Sisyphean obligation to meet a baseline ideal is merely relief from an impossible task.  In Marris’ rambunctious garden, she brazenly lets the weeds grow and openly accepts that some plants will crowd others out.  But she maintains that this is preferable to a carefully controlled system requiring constant attention to a static ideal.   In essence, she favors the ongoing process over the existing pieces.

Such a respect for process has intuitive appeal to scientists and conservationists.  Yet a sense of unease with this ad hoc approach undoubtedly remains.  On a local level, biodiversity might increase by embracing novel ecosystems, but globally the net loss of species continues, in part because of exotic invaders taking over existing ecosystems.  Does that matter?  Only if we want it to.