What do we mean by “natural”?

In watching New Mexico’s fires the past few weeks and talking to my forest ecosystem brain trust, I’ve been repeatedly struck by the set of questions Emma Marris raises in her new book Rambunctious Garden (great, recommended) about what baseline we’re thinking about when we talk about restoring natural systems that are currently badly out of whack.

In particular, I’ve been talking to USGS ecologist Craig Allen and some of the other folks he has worked with over the years on fire history of the Jemez Mountains, where the Las Conchas fire burned so hot and fast. (More on that in some coming newspaper work.)

This comes up a lot in discussions of the Sacramento-San Joaquin Delta, as well, a system about as badly out of whack as out of whack can be. While in California last month, I heard about some work being done by folks at the San Francisco Estuary Institute on historical and paleo ecology of the Delta. The new Delta Stewardship Council Science News has an interesting account of what they’re doing, and why:

The goal of the project is not to create a literal template from which to recreate the historical Delta since the Delta has undergone extensive changes over the years. Rather, the objective is to better understand ecosystem function and how it varied throughout the system in response to identifiable physical gradients (e.g. salinity, tidal range). This can inform large-scale restoration strategies currently being considered for the Delta.

The Institute’s work raises a lot of the same questions I’ve been thinking about in regard to forest systems here, especially one of scale:

In considering how to restore important ecological functions that have been lost, scientists and managers have recognized the importance of thinking at larger scales. “For instance,” Whipple said, “a restored tidal marsh might provide really different ecological functions depending on whether it is five acres or one hundred, whether it is adjacent to riparian forest, or whether it receives winter flood flows. We need to think about more than just habitats as single units, but how habitats are arranged into mosaics (complexes of different communities of species), and how those mosaics fit together in the landscape.”

You could say the same thing about the patches of forest around Los Alamos that we’ll be talking about a lot in the next few years. Given that there’s no going back to the pre-grazing, pre-fire suppression, pre-homes in the woods, pre-global warming world (or the pre-Delta farming and water export world), how do we decide what sort of “nature” we’re trying to preserve/create?

5 Comments

  1. Great thoughts, John! This is a question that routinely comes up in the various restoration projects I’m involved with. We forget, rather easily, that an ecosystem is a dynamic entity. It’s much easier to work towards some sort of static endpoint but there really aren’t endpoints in nature.

  2. Sarah –

    You’ll love Emma’s book. She travels all over the world looking at exactly the question y’all wrestle with every day.

  3. Lots of folks trying to answer those questions, John. The conf at which I spoke in PHX in March was full of that sort of discourse, and your snippets were all I heard in grad school for 2 years. But the speed of destruction of ecosystems and advancement of Anthropocene are no match for our glacial advancement of knowledge on these complex topics.

    Best,

    D

  4. Three thoughts.

    1. There is no static time and place that is ‘natural.’ Natural for England, meaning England before man started to change it 10,000 years ago, was completely forested, no grasses, heaths or moors. Since then, nature evolves in a constant battle of survival.
    2.Natural for horses, without the presence of man, is ‘extinct.’ Without horses allowing themselves to become tame, horses would have all died out.
    3. What does ‘preserve’ mean? Often the preserved place turns out to be some place that never existed and is unsustainable-think Australia with cows and rabbits but without dung beetles or myxomatosis.

    Interesting topic.

  5. hi John,

    great question. it is one that has been rattling around in my brain for, well, some time now. Doug Sprugel posed this question for ecologists in his provocative paper “Disturbance, equilibrium, and environmental variability: What is ‘Natural’ vegetation in a changing environment?” from 1991 – http://bit.ly/n2c9qx

    Pollan’s intro to the Botany of Desire, surprisingly, helped me solidify how we should think of nature and what is natural. In particular, it helped solidify my thinking through other readings like Bill McKibben’s “An Explosion of Green” – http://bit.ly/nytlLf

    Basically McKibben argued that just because a forest was cut, heavily or not, its reservation as natural area justified treating it like an ‘untouched’ forest. his comparison to rape in that article makes me cringe a bit, especially when i gave the article out to students to read, but his point is right on. today Sterling Forest, the center point of his essay, is a wonderful tract of land where I’ve done some research [wonderful & rare spruce-Atlantic white cedar wetlands] and where folks hike, hunt, boat, etc. In 100 yrs, folks will think of it as wonderfully natural [even ecologists, i suspect].

    Pollan’s argument in the Botany of Desire put humans in the construct of nature. given, to a certain degree, that the 20th century has brought ‘an end of nature’ [Bill’s dark essay on Nature], Pollan’s argument allowed me to embrace the ‘unnatural’ Nature described in the End of Nature. from there, we can then say, “ok, forget about what has happened in the past via human land-use [to a certain degree]. here are the players in our systems. here is what they ‘need’. let’s strive to give them the room and processes they need to be wild, no matter what happens to the climate.

    i’m still not ready to give in to invasive species – http://www.sciencefriday.com/program/archives/201107156 – they wreak havoc in many ecosystems. but, there is no doubt that we have to adapt to them in ways and find a balance. There are just too many and I fear non-native entering ports today and over the last 30 years will rear their ugly heads sometime in the next 50 yrs; hemlock woolly adelgid, now destroying hemlock forests in the east, has been in the country since the 1920s.

    from these perspectives, we can reduce the $$ spent on losing battles – maintaining ‘pristine’ ecosystems, and shift the focus to our ports to keep out non-natives and buying and preserving more green space. to date, this seems like the best solution to me.

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