By Jules Bernstein | Photos by Stan Lim
Every morning, UC Riverside ecologist Lynn Sweet, Ph.D. ‘11, awakens to the sight of Joshua trees extending out from her front yard and into the skyline.
At work, she attempts to preserve this stretch of desert, and the plants and animals that live there, from the effects of climate change and other threats.
Studying Joshua trees isn’t just a scientific exercise for Sweet. She, her husband, their 2-year-old son, and their dog live in Yucca Valley, about a 5-minute walk from Joshua Tree National Park’s entrance.
“It’s where I feel at home,” said Sweet, who has been working in the field of conservation for 17 years.
True to her New England roots, Sweet has a humble, down-to-earth approach to life, quite literally. She is much more comfortable outdoors, examining the health of her beloved flora and fauna than she is talking about herself.
Growing up in rural Orono, Maine, some of Sweet’s happiest early memories involve hiking the forest trails behind her house with her librarian father.
“Dad would bribe us to go on really early morning hikes with the promise of blueberry pancakes as a reward,” Sweet said. “But we never really needed an incentive. The hikes were their own reward.”
One of the first books she remembers reading was about mythical flower fairies, which “made the outdoors seem magical,” she said.
Given this upbringing, it’s no surprise she majored in biology at Pennsylvania’s Dickinson College. Though animal studies fascinated her, it was really a junior-year field trip to Tennessee’s Great Smoky Mountains that helped determine her professional direction.
“We camped in the Smokies and learned how to identify trees without any leaves, based only on their bark and the growth direction of the twigs,” she said.
“I was hooked.”
For the next several years, Sweet’s desire to understand outdoor environments took her all around the country. An internship with the U.S. Department of the Interior’s Bureau of Land Management in Cody, Wyoming, had her looking for wild horses and riding all-terrain vehicles. Another with the National Park Service had her catching birds for malaria research in Hawai’i Volcanoes National Park. Yet another internship, this time with the U.S. Fish and Wildlife Service, involved surveying an endangered bird species, the southwestern willow flycatcher, in the mountains east of Phoenix.
“These experiences taught me that the landscape was where my heart has always been,” Sweet said.
To help protect it, she came to UC Riverside in 2006 to study with Jody Holt, who was chair of the Department of Botany and Plant Sciences at the time. Holt served as a mentor for Sweet as she progressed toward her doctorate in plant biology, and she supervised Sweet’s research on invasive African fountain grass.
After all her travels, Sweet has found a forever home with UCR. She is a plant ecologist at the university’s Center for Conservation Biology at the Palm Desert campus, where she surveys rare and threatened plants and animals to help local land management agencies conserve them.
“I especially love the desert,” she said. “Some people think there’s not much here, but I could go outside right now and immediately find 100 fascinating things to show you. The alien-like rock formations, the lichens, the unique way the light filters through the trees … all of it.”
Most recently, Sweet’s work outlining the fatal effects of climate change on Joshua Tree National Park’s majestic namesake trees generated the kind of publicity — and requests for her on-camera expertise — that still makes her a bit squeamish.
Her study modeled several possible outcomes. In the best-case scenario, she and her team found that major efforts to reduce heat-trapping gases in the atmosphere would save a mere 19% of the famous trees’ habitat after the year 2070. In the worst-case scenario, with no reduction in carbon emissions, the park would retain a mere 0.02% of its Joshua tree habitat.
News of the trees’ near-extinction reached a national audience and Sweet’s research directly influenced U.S. Senator Dianne Feinstein to argue for the trees to receive endangered species status.
But Joshua trees are not the only aspect of the landscape that she studies. The Joshua Tree National Park project, which started in 2014, looks at multiple plants and lizards in the park to understand their health. There are plans in place for Sweet and her team to monitor piñon pines, California junipers, black brush, big galleta grasses, and 45 other shrub species for the next decade.
She is also helping lead the charge to protect another beloved local, the desert tortoise.
“I note the locations where the tortoise has been seen and add this to other information about the landscape in these places,” she said. “Was it found at low elevation? Near what kind of vegetation? What was the air temperature like when it was seen? The slope of the hill it was on?”
She then makes a map based on this information that Marines at the Twentynine Palms Marine Corps Air Ground Combat Center use to help protect the tortoises.
Sweet is also helping to inform a conservation plan for the entirety of the Coachella Valley, a roughly 45-mile-long area extending from the San Bernardino Mountains to the northern shore of the Salton Sea.
She and her team are looking at all aspects of the desert ecosystem to assess any decline in health. This includes taking groundwater measurements and monitoring mesquite, a tree that has been important to Native Americans and migrating birds, and which mainly grows in areas with surface groundwater.
In Sweet’s view, one of the biggest threats to the desert is the invasion of nonnative plants, such as tamarisk, a tall, shrubby tree originally used for erosion control.
“Water is precious here in the desert, and this shrub is moving in, taking the water, and displacing native species,” she said.
Bolstering her efforts to combat invasive plants, Sweet has had a seat on the California Invasive Plant Council’s board of directors for the past four years. The council, also known as Cal-IPC, is a nonprofit composed of land managers and state employees that maintains a list of plants to help Californians identify problematic species.
To help natural resource managers from across the state learn from one another and coordinate efforts to stop the spread of pesky plants, Sweet is helping organize a symposium this fall. She notes with pride that there are three other female UCR graduates on the organizing board, and that they successfully advocated for the symposium to be held in Riverside for the first time in the organization’s 27-year history.
The conference has been overhauled this year, with more focus on diversity and inclusion. There will be lactation rooms, gender-neutral restrooms, and speakers who will advise people on being more mindful of equity issues in their work.
Sweet participates in Cal-IPC’s Equity, Diversity, and Inclusion Committee, which promoted these changes. The committee helps the nonprofit diversify the materials they produce and appeal to a broader range of people in the field.
“Being more inclusive of women and other underrepresented groups can only benefit the whole land management community,” she said.
Future focused in many ways, Sweet is also helping inspire the next generation of scientists. She is partnering with a company called JASON Learning on an ecology webinar that will add to the science curricula in schools across the nation.
“I want to be a role model, particularly for girls interested in science, technology, engineering, and math subjects,” she said. “I hope the webinar, and this interview, will inspire a young person to pursue their scientific passions.”