Natural Beauty at Risk:

Preparing for Climate Change in National Parks

by Kathryn Hansen design by Joshua Stevens May 12, 2016

When most of us think of National Parks, we think of open spaces and healthy, abundant vegetation. We think of forests and woodlands and meadows and wildflowers—all preserved from development. We think of scenic vistas that inspire poets and artists and millions of everyday citizens. These lands are set aside, as Theodore Roosevelt put it, to preserve "the value of natural beauty as a national asset," and to promote "outdoor life and recreation in the production of good citizenship."

Rain falling over Yellowstone's Lamar Valley

The summer brings rain and warmth to the Absaroka Range, found at the eastern edge of Yellowstone National Park. Climate change may lead to an increase in temperatures and a decrease in snowpack in the park over the coming decades. (Photo by the National Park Service/Neal Herbert.)

But no matter what laws you pass or fences you build, you cannot shelter entire landscapes from the stresses of changing weather and a warming climate. The National Park Service (NPS) manages more than 400 parks, monuments, and historic sites from north of the Arctic Circle down to the Caribbean and the South Pacific. The NPS challenge is to preserve natural and cultural resources while making them accessible to the public. But land managers and park rangers can only do so much when the environment changes but the park borders do not.

Ecologists know that the trees that add color, beauty, and shade to America’s national parklands are at risk. Unlike animals, trees cannot pull up their roots and quickly migrate to another area. But figuring out which trees are the most vulnerable is complicated. The types of trees and forests vary from park to park, and even within some parks. Projected shifts in rainfall and temperature patterns in the future are just as variable and uneven. Some species will thrive as climate changes, but many are expected to suffer. And the question is: what can park managers do about it?

“There’s been a huge shift in the way the science community approaches climate change," said John Gross, an ecologist with the National Park Service's Climate Change Response Program. "We used to ask: is climate change happening? Then we asked: by how many degrees will the temperature rise? Now we ask: what does that mean for managing things?”

Graph of projected temperatres in the Greater Yellowstone Ecosystem

Representative Concentration Pathways (RCPs) are one way scientists model expected outcomes under different conditions. Under both moderate (RCP4.5) and increasing (RCP8.5) greenhouse gas concentrations, the Yellowstone area will experience temperatures significantly higher than the historic average. (NASA Earth Observatory chart by Joshua Stevens, using data from the Landscape Climate Change Vulnerability Project.)

In Yellowstone National Park, for example, spruce and fir forests have adapted to and thrived in a climate where summertime temperatures rarely surpass 90 degrees Fahrenheit (32° Celsius). But 30 years from now, if climate models are right, the park will see an average of two weeks every summer with temperatures surpassing 90°F. Will the spruce and fir trees suffer? Will they adapt and thrive? Will they migrate, seedling by seedling, up to higher altitudes and cooler temperatures? If trees that are already adapted to warmer temperatures take hold, will spruce and fir be able to compete?

In order to figure out what changes the parks can expect, scientists from Montana State University, the Woods Hole Research Center (WHRC), the National Park Service, and NASA established the Landscape Climate Change Vulnerability Project. They want to use scientific observations and computer models to help the parks adapt to climate change.

With mountains of data being collected by satellite- and ground-based instruments, scientists can now paint high-resolution pictures of changes within individual parks—down to the effects on various stands of trees. “Computationally that’s a big deal,” Gross said. “Even on a supercomputer, to produce that data is a big deal.”

Maps of biome change expected within and around Yellowstone Nationkal Park

Climate change can make an area less suitable for some trees and plants—and more suitable for others. Within several decades, the primary vegetation found around Yellowstone is predicted to undergo substantial transformation. (NASA Earth Observatory map by Joshua Stevens, using data from the Landscape Climate Change Vulnerability Project.)

The data and models could give park managers context and insight on when and where to let nature manage the park and when human intervention could help. For instance, which species and forest stands should managers focus on? Where would it make sense to plant new stands of trees, and which species would benefit?

“If temperatures keep increasing, things will shift in ways that parks haven’t seen before,” said Patrick Jantz, an ecologist at the Woods Hole Research Center. “So there’s been a shift in the parks from managing for historical conditions—to bring things back to a pristine ecological state—to a whole new way of thinking: managing for species turnover.”

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