How climate change is spawning a new view of conservation
Conservation has long been about protecting communities of plants and animals where they are. But climate change is leading to a nascent form of conservation that embraces change and seeks to provide a thriving stage on which it can happen.
Chester, Mass. — It's a late-July morning, and Andy Finton works his way up a trail in western Massachusetts' Berkshire Hills, walking beneath a canopy of sugar maple, ash, beech, and basswood.
At one point, Mr. Finton pauses and announces with a chuckle: “Congratulations! You’re on a steep slope.”
Finton, who works for the Nature Conservancy, was pointing out something more profound than his announcement might suggest. A steep slope is a crucial element of an emerging vision to help plants and animals survive and adapt to a warming world while maintaining high levels of biological diversity.
Conservation efforts typically have focused on maintaining a pristine forest or wetland, or preserving specific species or communities of species where they are.
Yet a growing body of research shows that when you scratch the surface of a biodiverse region, you'll generally find diverse soil types, elevation ranges, bedrock types, and features such as canyons, cliffs, ravines, and Finton’s steep slopes.
The new approach focuses on conserving landforms in a region that incorporate these diverse geophysical traits – which act as stages on which biological diversity thrives. And it focuses on setting up corridors between the “stages” to allow for species migration.
As the scientific evidence of global warming has mounted, conservation often has focused on finding ways to help species or communities of plants track their preferred climate conditions, where possible. For example, a certain tree species might need to move about 30 miles a year higher in latitude to stay within its preferred climate range.
By focusing instead on conserving diverse settings, species may be able to find refuges closer to home.
The tree species might not have to move 30 miles a year to survive, Finton says. “It just needs to move around to the north side of the mountain.”
The approach is just now gaining momentum. The Berkshire Hills trail winds up a hill at the southern end of one of four areas from West Virginia to Maine being targeted for “nature’s stage” style conservation by the Open Space Institute.
The Nature Conservancy is using the approach in its land-acquisition decisions and advocacy, and states such as Maine, Massachusetts, and Tennessee are beginning to embrace the idea.
Adoption is slow, acknowledges Peter Howell of the Open Space Institute in New York. But “you’re starting to see an uptick” as scientific information is making its way to conservation groups and the foundations that help fund them, he says. [Editor's note: The original version misstated Mr. Howell's name.]
A shift in thinking
The concept initially appeared in conservation circles in 1988. At that point, ecologists were already moving from efforts to save individual species to efforts to preserve the broader communities in which species lived.
A trio of scientists from the University of Maine and Brown University suggested that, given climate change, physical environments – not plant communities – provided the best basis for identifying land to conserve. They noted that the plant communities that emerged since the last ice age still haven't stabilized; change is the norm and this would become even more pronounced amid an era of global warming.
Instead, the team argued, the focus should be on conserving physical settings and corridors connecting them. That approach will embrace the communities you're interested in conserving.
The approach recognizes that changes to climate alone don't determine where plants, insects, and ultimately animals will migrate, if they can. Soil types, topography, underlying bedrock types, and latitude exert the most significant influence on a landscape's potential to host a rich mix of species.
In western Massachusetts, the journey up the steep slope reveals the relationship between biological diversity and landforms. The basswood and ash trees, for example, prefer the accumulated soils and nutrients found at the hill's base. Higher up slope, these and other trees give way to mountain maple and oak, which eventually yield to pitch pine. The pitch pine can survive in the shallow, dry soils at the summit.
Later in the day, along a dirt road that tracks Sanderson Brook, Finton points to patches of stinging nettle and explains that the plant is found in flood plains, but not on the hill's slopes.
Climate still plays an important role on a range of scales – from the regional down to individual mountainsides. Diverse settings can set up their own microclimates, which can provide refuges for plants threatened by regional climate change.
The new approach offers hope for helping existing species cope with climate change, up to a point.
If climate change is too severe, no strategy is going to work, says Mark Anderson, science director for the Nature Conservancy's eastern region.
Which settings to protect
But how do you determine which physical settings you want to preserve?
In 2010, two different research groups came to similar answers and published their conclusions within 45 days of each other.
"It was uncanny," says Paul Beier, a forest ecologist at Northern Arizona University.
His team gauged what it called geodiversity by an area’s underlying bedrock, topography, and specific landforms.
Meanwhile, Dr. Anderson used satellite data to map different landscape types across the US Northeast and eastern Canada to see which factors best corresponded with biological diversity.
His team found, for example, that range of elevations across a landscape and high limestone levels in the bedrock were among the four best predictors of high biodiversity. And all four factors were geophysical.
For its part, the Open Space Institute is using these principles – and a $12 million grant from the Doris Duke Charitable Foundation – to help build a network of climate-resilient landscapes in four areas in the US Northeast and Southeast.
The institute parcels out the money as grants to local land trusts that want to set aside land and have adopted nature's-stage criteria. They also work with state and local agencies.
The elephant on the stage
For all its recent progress, however, the nature's-stage concept carries caveats, notes Jacqueline Gill, a paleoecologist at the University of Maine.
For instance, climate change itself can change landforms as more-frequent and more-intense rains accelerate erosion in some regions.
Moreover, the approach may not be appropriate for keystone species, which still may require species-specific intervention.
"The ice-age record tells us that losing large keystone animals like mammoths and giant ground sloths has significant consequences for the rest of the ecosystem, and we're only just beginning to understand those consequences," she says.
Elephants represent one current example of keystone species that require a custom conservation touch. Elephants create a great deal of habitat on which a range of plants and animals relies, Dr. Gill notes.
"It's not a popular idea necessarily, but not all species are created equal" she says.
And scientific questions about the approach have yet to be answered.
“The question we'd really like to answer,” says Gill, “is whether geodiversity has corresponded to biodiversity through time – and how landform durability influences biodiversity.”
From the Amazon to the Berkshires
A project in the Amazon could begin to provide answers. The project aims to test the idea that the rise of the Andes Mountains some 10 million years ago essentially doubled the diversity of plants in Amazonia by, among other effects, providing a narrow slice of unique microhabitats along the range's eastern slopes as it rose.
The region hosts some 90,000 plant species, says Christopher Dick, an evolutionary biologist at the University of Michigan and one of the project's co-investigators. Of those, 45,000 appeared with the uplift of the Andes. The rest appear in the Amazon basin, which by some estimates is between 50 million and 100 million years old.
The basin is something of a museum for large numbers of very old species, Dr. Dick says. The slopes of the Andes are where more-recent evolutionary action has occurred – driven, the team posits, by changes in the geophysical setting.
Back in the Berkshires, Finton sums up the goals behind conserving nature's stage: “We're trying to prevent extinction in the face of climate change.”