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“It’s turning conservation on its head,” said Bill Stanley, who directs the
global climate change initiative at the Nature Conservancy. He said the
organization has a goal to protect 10 percent of major habitat types –
like grasslands, forests and freshwater systems – by 2015.”
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The New York Times
January 29, 2008
The Preservation Predicament
By CORNELIA DEAN
Conservation organizations that work to preserve
biologically rich landscapes are confronting a
painful realization: In an era of climate change,
many of their efforts may be insufficient or
beside the point.
Some scientists say efforts to re-establish or
maintain salmon runs in Pacific Northwest streams
will be of limited long-term benefit to the fish
if warming makes the streams inhospitable. Others
worry about efforts to restore the fresh water
flow of the Everglades, given that much of it
will be under water as sea level rises. Some
geologists say it may be advisable to abandon
efforts to preserve some fragile coastal barrier
islands and focus instead on allowing coastal
marshes to migrate inland, as sea level rises.
And everywhere, ecologists and conservation
biologists wonder how landscapes already under
preservation will change with the climate.
“We have over a 100-year investment nationally in
a large suite of protected areas that may no
longer protect the target ecosystems for which
they were formed,” said Healy Hamilton, director
of the California Academy of Sciences, who
attended a workshop on the subject in November in
Berkeley, Calif. “New species will move in, and
the target species will move out.”
As a result, more and more conservationists
believe they must do more than identify
biologically important landscapes and raise money
to protect them. They must peer into an uncertain
future, guess which sites will be important 50 or
100 years from now, and then try to balance these
guesses against the pressing needs of the present.
“It’s turning conservation on its head,” said
Bill Stanley, who directs the global climate
change initiative at the Nature Conservancy. He
said the organization has a goal to protect 10
percent of major habitat types – like grasslands,
forests and freshwater systems – by 2015.
“We are not sure exactly how to treat this yet,”
Mr. Stanley said. “Areas that we preserved as
grasslands are going to become forests. Does this
mean we are going to have to have more than
enough forest and less grassland than we had
before? Or does it mean we should fight it – try
to keep the forest from coming into those
grasslands? Or should we try to find new areas
that are least likely to change, that seem to be
the least susceptible to change, and prioritize
those areas?”
As Dr. Hamilton put it, “Our whole strategy is going to have to shift.”
No one is suggesting that land conservation done
so far has been a wasted effort. Many argue that
preserved areas will contribute immensely to
ecosystem resilience as the climate changes. For
example, environmentally intact salmon streams
will undoubtedly be useful if new species move
into them. And even if much of the Everglades is
lost to a rise in sea level, preserving the rest
will be crucial for maintaining fresh water
supplies in South Florida, said Dan Kimball,
superintendent of Everglades National Park.
Mr. Kimball said that if the Intergovernmental
Panel on Climate Change was right, and sea levels
rose as much as two feet by the end of the
century, up to 50 percent of the Everglades’s
fresh water marsh “would be transformed into a
salt water system.” But, he said, restoring the
fresh water flow might “create a fresh water
barrier, hopefully, and keep the rising seas at
bay.”
The Everglades ecosystem is full of
uncertainties, Mr. Kimball said, explaining that
“we don’t know the rates of change.” If seas rise
faster than the climate panel predicted in its
report last year, which many scientists regard as
likely, mangroves crucial to the health of the
glades could be submerged. But “if it’s slow,” he
said, “the mangroves could gather sediment and
actually build landform” – something that he said
happened after Hurricane Wilma washed over the
vast wetland in 2005.
This kind of uncertainty is widespread. For
example, Dr. Hamilton said that on the Northern
California coast, fog has an influence on natural
systems. But “none of our climate models can tell
us what is going to happen with fog,” she said.
“So we are facing profound uncertainties about
how our coastal ecosystems are going to look.”
“It’s a real dilemma,” said David S. Wilcove, a
conservation biologist at Princeton. “What you
are trying to do is balance the urgent needs of
the present – the ongoing destruction of habitats
that species need now – with the urgent needs of
the future – places where they may end up if they
are able to move in response to changing climate.”
Mr. Stanley said that to cope, the Nature
Conservancy was adopting new strategies, which
include identifying for preservation potential
refuges against changing climate, landscapes that
have had relatively stable vegetation over
thousands of years, and removing or reducing
other stresses on the landscape, particularly
activities by people.
Other plans are to search for resilient species
or subspecies that can cope with a warming trend.
For example, conservancy scientists looked at
which reefs did best when Caribbean waters warmed
in an El Niño event in the late 1990s.
“We said, ‘Why did they survive, and are they the
ones most likely to survive in the future?’ ” Mr.
Stanley said. Resilient strains could be used to
restore damaged reefs. “The same approach could
translate to the land,” he said. A pair of
apparently contradictory strategies are to find
new ways to preserve particular landscapes by,
say, burning out plant species trying to move in
or, the opposite, to encourage habitat alteration
by creating open space “corridors” that plants
and animals can use to move between protected
areas.
Still others are looking for ways to encourage
people who own property near protected areas to
manage them so that target species will be able
to move into them. For example, Dr. Hamilton
said, there are vineyards with patches of forest
adjacent to protected sites along the California
coast near Mendocino. “We have to make sure those
winegrowers are incentivized for keeping those
patches of forest on their land,” she said.
Some scientists say it may be necessary one day
to move plants and animals into new areas and are
working to devise theoretical frameworks for
deciding when, how or whether to act.
“This term ‘assisted migration’ is gaining some
traction,” said Dr. Wilcove, who formerly worked
with the Wilderness Society and Environmental
Defense. But “it’s a tough call,” he added. “What
you are basically doing is moving species to
places where they do not occur but where you
think they will be suitable. But we often get
into trouble translocating species for all kinds
of unexpected reasons that come up.”
Coastal ecosystems are likely to be the first to
pose difficult conservation problems, as sea
level rise inundates protected areas or makes
them more vulnerable to damage in storms.
For example, Asbury H. Sallenger, an
oceanographer at the United States Geological
Survey and an expert on coastal hazards, said
conservationists had been considering massive
sand-pumping efforts in hopes of restoring a bird
habitat on the Chandeleur Islands, barrier
strands off the coast of Louisiana that were
severely damaged in Hurricane Katrina and other
storms. But with sea level rise accelerating, Dr.
Sallenger said in an e-mail message, “there is
reason to believe these islands may disappear
much more quickly than we thought just a few
years ago.”
As a result, Dr. Sallenger said, the agency was
working to estimate the projected lifespan of the
islands, should they be rebuilt to their
configuration of the late 1990s. “In other
words,” he said, “will the time gained be worth
it.”
But while many realize that ocean beaches are
threatened by climate-related sea level rise,
they do not understand that coastal wetlands –
crucial nurseries for fish and shellfish – are at
least as vulnerable, much less likely to be
preserved and, in many areas, penned in by
development and unable to migrate inland, as they
would naturally as seas rise.
“We need to be preserving upland areas to allow
for the landward expansion of wetlands,” Robert
S. Young, director of the Program for the Study
of Developed Shorelines at Western Carolina
University, said in an e-mail message. “Sadly,
this isn’t happening in any serious way.” Dr.
Young said his program was beginning an effort to
get this point across to the public.
Some conservationists advocate triage, accepting
that some ecosystems, like coral reefs, may not
survive in a warmer world, and putting their
efforts elsewhere. Others, like Mr. Stanley at
the Nature Conservancy, are not ready to give
ground. “I don’t think those analyses take into
account the resilience,” he said. “We are less
focused on triage and more focused on resilience.”
Roger Kennedy, former director of the National
Park Service, said Americans had been making and
remaking conservation strategies since colonial
days.
In that era, Mr. Kennedy said, people conserved
green space, like Boston Common, close to where
people lived densely. Later, he said,
conservationists preserved “very special places,”
like Yosemite, Grand Canyon and what became
Glacier National Park – efforts encouraged by
railroads, which anticipated that Americans would
travel by train to see them.
It was only in the late 19th century that people
began thinking of preserving vast swaths of land
for plants and animals that inhabit them. He said
he believed this ethic of preservation would
succeed, even in a warming world.
“Over time, all systems have altered,” Mr.
Kennedy said. “They are just changing more
rapidly. But our means of accommodation are
greater too.”
Copyright 2008 The New York Times Company
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