"One exceptionally well-monitored project
in southern California, where less than 15 percent of the historic expanse
of tidal marsh remains, illustrates just how far from complex natural functioning
an otherwise authentic-looking wetland can be. Restoration at the site,
known as the Sweetwater Marsh National Wildlife Refuge, represents a federally
mandated effort to provide suitable habitat for two endangered birds and
also to reestablish populations of an endangered plant.
"Dr. Joy Zedler of San Diego State University
began tracking progress and conducting research in the new march in 1989,
five years after it was created from former marsh and mud flats... her
team successfully seeded the endangered plant, the salt march bird's beak...
small native fish that provide food for one of the endangered birds, the
California least tern, have returned to the reconstructed channels. The
terns, however, rarely fish for reasons still unknown.... and the elusive
clapper rail has been even harder to please.
"....the restoration project is still
underway... indeed the outcome of projects like these may not be clear
for decades or longer.... Creating suitable habitat and recovering lost
functioning has proven a tough assignment, and not just in Sweetwater Marsh.
When Zedler examined coastal mitigation projects throughout Southern California,
she found no instance where ecosystem functioning had been successfully
duplicated or where endangered species had been "rescued from the
threat of extinction." A 1992 report by the U.S. National Academy
of Sciences concluded much the same for all types of wetland restorations
throughout nation: There is no evidence that these restored wetlands can
recreate fully functional ecosystems and they cannot be relied upon to
maintain biological diversity."
"Certainly, restoration projects should
be encouraged... The National Academy report itself called for restoration
of 4 million hectares of already degraded wetlands in the U.S. There are
millions of more hectares of rangelands, forests and march on every continent
that might be restored to health and productivity if complex environments
could be rebuilt as skillfully as they are dismantled. As for the earth's
dwindling stock of natural and semi-natural landscapes, it would be far
less costly to preserve natural systems rather than count on being able
piece them back together after they've been torn apart. ...the current
track record of restoration offers nothing on which to stake the fate of
the earth's functioning ecosystems.
"...policy makers tend to behave as though
the survival of most non-human organisms is an amenity, one that future
generations of humans can live without. Everything scientists are learning
about the earth's life-support processes argues against this view. It's
time to complement our sense of obligation as stewards of the earth with
a somewhat humble sense of self-preservation, to acknowledge that despite
our increasing estrangement from nature, even urban societies are profoundly
dependent upon it.
"... Most industrial societies tend to
disregard and devalue ecosystem processes, opting instead for a technological
fix whenever environmental services falter. Lost services are replaced
not with natural mimics but with engineering solutions: dams, reservoirs,
waste treatment plants, air scrubbers, air conditioners, synthetic pesticides
and fertilizers and water filtration systems. Replacing natural systems
that work for free with engineered systems powered by fossil fuels is enormously
expensive, often problem-plagued and commonly impractical.
"...Right now, the natural level of diversity
is the best proxy scientists have for healthy functioning, and all species
losses are warning of potential malfunctions.
"...With human population still expanding
exponentially, our species is hardly likely to take up less space or exploit
fewer resources in the future. Now, more than ever, we need to learn how
to use lightly and sustainably the natural systems that survive in our
midst.".
received the most amazing book. If you're interested
in what the state of the art and the consensus of the global scientific
community is on the status of biodiversity and nature... or if you've ever
wondered what the heck is this biodiversity thing and why is it important...
check out The Work of Nature: How the Diversity of Life Sustains Us,
by Yvonne Baskin, published by Island Press, with an introduction by Paul
Ehrlich.
