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Ecosystems
that have not been disturbed for long periods of time (whether
by humans or by natural
disasters) tend to reach a state of dynamic equilibrium
which ecologists call a climax phase, meaning
that organisms have adapted themselves to one another
in such a way as to maintain relatively
constant population levels, to avoid direct
competition, to keep energy flow-through to a minimum,
and to recycle available energy and nutrients as completely
as possible. They have formed, to use
an anthropomorphic term, a community. – Richard Heinberg, The
Party’s Over
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As I write this column I am a few days away from heading to my
farm in North Dakota for my annual two weeks of “working
vacation.” I always long for this time of year when I can
actually “be there” on the farm. It is like rejoining a
community I have missed.
And, as I have learned over the years, our farm truly is a
“community.” The crops, animals, wildlife, native and introduced
species (and the farmers) – even the soil micro-organisms – form
an interdependent set of relationships. Wastes from one organism
become food for another, and all tend to adapt themselves to
each other. From my perspective it isn’t always benign, but it
is a community.
Such relationships have real value. Wendell Berry once told me
that the sheep on his farm have adapted to the place (the hilly
landscape and unique grasses that are native to his area) such
that they would be less valuable in another landscape. To be as
productive elsewhere, they would have to go through a process of
adaptation that would require energy – a cost to the animals and
no doubt to the farm.
Some time later I asked a retired animal scientist friend of
mine if this was true. He said, “Oh yes. In fact in Scotland an
animal always was considered more valuable when it was sold with
the farm than when it was sold separate from the farm. When it
was sold with the farm it already was adapted to the place.”
There are clues in this kind of ecological thinking that may be
important for us to keep in mind as we attempt to deal with
impending constraints such as peak oil, climate change,
diminishing groundwater resources and other challenges. We tend
to try and solve these problems by inventing novel technologies,
without attending to their potential ecological consequences for
the biotic community.
In past months the news media have been featuring the prominent
role that “synthetic biology,” the science of rearranging an
organism’s entire genetic code, can play in solving our energy
crisis. (See Nicholas Wade’s column, “Genetic Engineers Who
Don’t Just Tinker,” in the July 8 New York Times, and John
Carey’s “On the Brink of Artificial Life” in the June 25
Business Week). Synthetic biology promises to bring us an
entirely new generation of organisms that can replace the goods
and services currently provided by fossil fuels.
We, of course, already have learned (sometimes painfully) that
the introduction of non-native species to an ecosystem can cause
major, unanticipated disruptions, and that the loss of a species
can produce extensive and unanticipated desolation, both of
which can have serious economic consequences. Just ask North
Dakota ranchers about the cost of invasive leafy spurge.
Having learned these lessons, ecologists like Kevin McCann now
caution us that there is only one way to proceed: “If we wish to
preserve an ecosystem and its component species then we are best
to proceed as if each species is sacred . . . species removals
(that is, extinction) or species additions (that is, invasions)
can, and eventually will, invoke major shifts in community
structure and dynamics” (emphasis mine). Thinking like a
community is critical, and it seems that such thinking is in
short supply as we attempt to deal with the challenges that
confront us.
Our present ecosystems provide farmers with incredible free
ecosystem services: pollinators, nitrogen-fixing organisms,
predator/prey relationships that keep pests in check. Creating
our imagined synthetic nature may not be a viable substitute for
the nature we already have!
We still know so little about the nature we have; consequently,
we could easily destroy vital ecosystem services without knowing
it. Research recently conducted at McMaster University in Canada
showed that plants can recognize their kin, suggesting that
gardeners could inhibit root growth by placing plant siblings
near each other and encourage root growth by placing strangers
close to one another. (It seems that strangers compete while
siblings do not.) What else are we missing because we know so
little about our biotic communities?
None of this is to suggest that we humans have no role to play
in disturbing nature or introducing innovations. Controlled
burns can reinvigorate grasslands. Cross-breeding can revitalize
plants and animals. We are part of nature and we can do our
part. But we must think like a community and use ecological
screens to help us decide which technologies to introduce and
which to forego because they may cause major shifts in the
community’s structure and dynamics. And we should do what we can
to enhance the community’s capacity for self-renewal (as Leopold
advised), rather than introducing novel organisms for the sole
purpose of serving our own immediate needs without attending to
the potential damage they could do to the health of the rest of
the community.
It is unlikely that we can do well unless the community does
well. We are, after all, “plain members and citizens,” as
Leopold so eloquently put it.
Fred Kirschenmann |