Finding the little pines in that particular place was just what the researchers were expecting, Millar says. The site, after all, rises directly above Patriarch Grove, a stand of ancient bristlecones where young trees are now pushing above timberline. The summit where the team is working today is not only a good 700 feet higher, it also sits at a farther remove from the grove. And while it would not be surprising, some day, to find a little limber pine here, so far no trees have materialized, just the expected contingent of high-elevation specialists like White Mountain buckwheat, pygmy fleabane and a rare alpine daisy along with more broadly distributed species: yellow rabbitbush, dwarf sagebrush, Sierra beardtongues.
"Ooh," says Catie Bishop, peering at a tiny Draba leaf through her hand lens. It's covered with delicate white hairs. "The phlox here has hairs, too," she says, "but they're not as spectacular." The hairs represent an adaptation to the harsh conditions that prevail at high elevations. Among other things, they shade the leaves from ultraviolet radiation; they also serve to deflect drying winds. The low stature of these plants is important, too. Almost uniformly, they huddle close to the ground, which, in summer, stays quite a bit warmer than the air and, in winter, lies under snow.
Of course, a number of the species that grow here can also be found at lower elevations and so should be able to handle some degree of temperature rise. Even within a single species, there are always individuals capable of accommodating a greater degree of climate stress. Virtually every species, for example, comes equipped with genes that encode so-called "heat shock" proteins, but there may well be subtle differences between, say, one Draba and another. In the Sierra, Smiley and his colleagues have discovered, willow leaf beetles equipped with one variant of the heat shock-gene do noticeably better under warmer conditions.
But the ability of species to cope with climate change is not infinite. Game changers — extreme events like disease outbreaks, wildfires and multi-year droughts — can reconfigure landscapes almost overnight. As resident plants and animals die off, migrants from adjacent areas swiftly move in to take their places. Even slow-paced change adds up. Indeed, it's easy to imagine how, over time, ground-hugging cushion plants might be marginalized by taller, faster-growing species that are making their way up from less harsh environments. There is a trade-off, says botanist Steve McLaughlin, a University of Arizona professor emeritus who is helping with the survey. "The general principle is that the adaptations that increase survival in stressful habitats, such as those that presently prevail at high elevations, reduce the potential for rapid growth."
Around noon, members of the team stop for lunch, parking themselves on a slope that opens to a panorama. From here, you can see the snow-streaked Sierra crest, the purpling ranges that roll like waves across the Great Basin, the dark, brooding canyon at the heart of the newly created White Mountains Wilderness Area. Closer in, white knobs of dolomite, a type of limestone, alternate with darker humps of granite and quartzite, which is metamorphically hardened sandstone. There are patterns in the vegetation as well. Bristlecone pines hew to soils derived from dolomite, whereas sagebrush gravitates towards the granite and the quartzite. No one knows exactly why, but the effect is pleasing.
"It's a mosaic," Millar says. And, indeed, you do get the sense of looking through a kaleidoscope that climate, along with other forces, has repeatedly twisted over time. The next turns of the kaleidoscope, however, are going to rearrange a landscape that is only partly natural. Even in this protected place, where the human footprint is relatively small, weedy Eurasian annuals can be found here and there, waiting to take advantage of any disturbance. "On the one hand, it's comforting that native species must be at least somewhat adapted to climate change," Millar reflects. "On the other hand, we are not going to like certain consequences, like species declines and weedy invasions."
Among the most unsettling impacts of climate change will be the transformation of iconic landscapes, a process that, in parts of the West, is already well under way. Over the past decade, for example, the Rocky Mountains have experienced a massive dieback of lodgepole and whitebark pine forests due to a combination of factors, ranging from drought exacerbated by rising temperatures to bark beetle infestations. It's as if a once-locked door has swung wide open, inviting passers-by in. In some cases, these forests may rebound; in others, they are likely to be replaced by some novel combination of native and non-native species.
The lunch break ends; the GLORIA team goes back to work. Draba. Rock. Rock. The cadence seems soothing, somehow reassuring, as does the steady progress Millar and the others are making. Quietly, methodically, they are compiling a chronicle of one of the most extraordinary epochs in Earth's history, the "Anthropocene" or human epoch, and their account seems destined to become a classic. Thanks to them, future generations won't have to speculate about the ecological impacts of greenhouse warming on mountain flora and fauna. They will be able to look back through the lists being assembled today and know how much has changed. Because an awful lot is going to change: All the ruggedness of this high, wild place cannot reverse the warming that is occurring, Millar says. It can only modulate its impacts.
"Right now," she says, "the only thing we know for sure is that there will be surprises."
J. Madeleine Nash is a freelance journalist and science writer based in San Francisco, California. Her 2009 HCN story “Bring in the Cows” (www.hcn.org/issues/41.9/bring-in-the-cows) recently won a 2010 Science in Society Journalism Award from the National Association of Science Writers, in the Local or Regional Science Reporting category.
This coverage is supported by contributors to the High Country News Enterprise Journalism Fund.
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