View from the mountaintop

On Nov. 3, North State residents will be offered a unique opportunity—a chance to pore through the extensive library of preserved native plants at the Chico State Herbarium during the annual Friends of the Herbarium-sponsored open house.

This multi-faceted no-cost event will include the colorful, artistic results of the Friends’ second-annual native-plant photography contest, as well as a talk on vernal-pool restoration by award-winning Chico State botany student Erin Gottschalk Fisher. It is, however, the Herbarium’s keynote lecture on the effects of climate change that is of special note.

U.S. Forest Service senior research scientist Dr. Connie Millar—who is also the chairperson of the North American chapter of GLORIA, the Global Observation Research Initiative in Alpine Environments—will deliver a talk based on her extensive, ongoing research at the USFS’s Pacific Southwest Research Station, in the eastern Sierra Nevada, between Mammoth and June lakes. Her lecture is titled “From Mountain Tops to Canyon Bottoms: Climate’s Variable Effect on Sierran Ecosystems.”

“I am going to be talking about the different processes of climate and how they influence mountain ecosystems,” said Millar in a recent phone interview from her office in Albany. “I will be working against a common view that with climate change [plant and animal] species will move [only] up the mountain. I am looking at mountain systems as offering more options than that.” Millar was, of course, referring to the popular notion that as global warming increases, mountain-based flora and fauna will migrate to ever-higher altitudes. This, she stressed, is simply not a given.

“In some cases, species may move down,” said Millar.

In contrast to places such as the Central Valley, which tends to have a fairly consistent climate and natural environment throughout, Miller explained, “mountains have very diverse environments that provide opportunity for species to have refugia”—areas that have not experienced the ecological changes that have occurred elsewhere and thus provide a suitable habitat for surviving species.

“Maybe [a species] will move down into cool canyons, for instance, where the phenomenon known as ‘cold-air pooling’—or an ‘inversion’—occurs,” she said. The undulating landscape of mountainous regions, in other words, offers many small microhabitats in its “down” areas that could attract species as they relocate in response to climate change.

“It is absolutely clear that our models are good as far as global warming is concerned,” Millar said. “There is no question that the world is warming; there is no challenging that. But what’s more important is how that plays out on the local scale.” A cougar, which has a wide-ranging habitat, will experience the effects of global climate change differently than, for example, a tiny American pika—which inhabits a very small microclimate in a rock slide.

“This matters if you are, say, a conservation biologist,” Millar said. “You have to talk about scale; you have to talk about each species differently. … You have to take into account the ecology of each species. Not all will be affected in the same way by a global trend.”

In addition to paying attention to the physical area that an animal or plant species inhabits, one also has to take into account the “time scale” relative to each species when attempting to determine the effects of climate change. Annual plants and small rodents with short life-spans—such as voles and mice—will be affected differently than species that live much longer, like the redwood and the bristlecone pine.

In the case of the pika, which has roughly a four-year life-span, for its entire life it could be living “in a warm drought,” which could adversely affect its ability to thrive over the long term. On the other hand, a long-living tree such as the bristlecone pine “has 5,000 years to replace itself.”

“This is very topical. This affects all of us,” said Linnea Hanson, retired USFS botanist and board member of the Friends of the Chico State Herbarium, of Millar’s talk. “Connie is working on the changes that are happening in the Sierra Nevada, which is our back yard, not what’s happening somewhere else very far away. It makes [the subject of climate change] more real, more personal, and I think it’s something we all need to be educated about.

“In my life, I’ve seen the climate change,” continued Hanson, who leads annual spring hikes to view the wildflowers blooming on Table Mountain. “When things bloom, it’s different now; the peak bloom is more variable now than it used to be. Understanding about climate change is important—even if it’s for nothing more than when to wear a sweater.”

“A lot of people think climate change just happened,” Millar noted. “This is not the case. The anthropogenic cause is novel, but there are many natural drivers [of climate change] that continue and have continued alongside greenhouse-gas issues.

“If you’re a conservation person or a resource manager, there are a lot of things you can do to work with a species’ adaptive abilities”—in other words, with species’ time-proven abilities to adapt to historic climate change.

Rather than despair about climate change and its effect on species, Millar wants to “present hope” and “put the knowledge we have to optimistic use, rather than throwing our hands in the air and sticking our heads in the sand. …

“The only certainty we know about plant and animal species is that they do go extinct, whether it’s by virtue of going ‘off the top of the mountains’ or otherwise,” said Millar. “It’s an oversimplification to say that mountain species are at risk of moving over and off the top of mountains.”