Conserving plants is one of the most significant challenges of our time—and a major focus at the Chicago Botanic Garden. From studying soil to banking seeds, from restoring habitats and protecting endangered plant species to developing new ones, Garden scientists are fighting plant extinction, pollution, and climate change through diverse and exciting research.
Last June, I headed up to Door County, Wisconsin, with Kay Havens, our director of plant science and conservation, for a 31-day trip to undertake our annual fieldwork. “A month at the beach!” you say, thinking it such a treat! Well, yes and no.
Four undergraduate students in our REU program joined us to track literal life and death events in two plant populations on the dunes of Lake Michigan. The dunes can be more than 20 degrees Fahrenheit hotter than ambient temperatures, and we work in the interdunal swales, where no lovely breezes off the lake can reach us. It is often well over 95 degrees in the dunes, even if it’s a balmy 75 degrees in Sturgeon Bay. But, no matter—we are on a mission! On days with the hot sun both beating down and reflecting up from the sand, we observed, measured, and recorded the births, deaths, and reproductive successes of one of our favorite plants: the threatened pitcher’s thistle (Cirsium pitcheri).
Pitcher’s thistle (Cirsium pitcheri)
We find every seedling we can, and place a flag next to it to help us keep track of the ones we’ve counted. We don’t want to miss a single one. Each seedling is a measure of successful reproduction for this monocarpic perennial. Monocarps—plants that only flower once before they die, are completely dependent upon producing as many successful offspring as they can, all in the quest to ensure that they just replace themselves. When all plants successfully replace themselves, a population is stable.
Just to replace yourself is a monumental undertaking for a plant that flowers once and then dies. Especially for pitcher’s thistle. The dunes are a harsh environment for a tiny baby plant. Many of them die—exposed to the heat, and without enough water to sustain them. We estimate that fewer than one in ten seeds germinate and survive each year, and in some years, only a small percent of those survive the winter to become a juvenile plant the next year. That means that each flowering plant must produce many seeds to replace itself. The good news? Generally, if a seedling survives to the juvenile stage, it has a much increased chance of survival to make it to the next stage—a vegetative plant—and the vast majority of those go on to reproduce at some point.
Kay Havens is ready to record data at Ship Canal Nature Preserve, owned by the Door County Land Trust.
However, seed germination and seedling survivorship and growth depend upon two things: where you come from and where you live. To look at this, we took 100 seeds from each of our two study populations and grew them in “seed baskets” in our study garden at the Chicago Botanic Garden. We also grew the same number in seed baskets at their respective home sites. Regardless of population, they germinated and grew very readily in our study garden. But there were very stark differences at our study sites in Door County: seed germination was 39% at one site, but only 9% at the other.
Pitcher’s thistle seedlings sprouted in one of our seed baskets at the Ship Canal Nature Preserve. The pair of yellow-green “leaves” opposite each other are actually cotyledons, or seed leaves, and are the first photosynthetic organs to emerge from the seed during germination.
These are pitcher’s thistle seedlings that have grown very large under the favorable conditions of the test garden on the south side of the Plant Science Center. In just one growing season, they have grown as large as plants three to four years old that grow under natural conditions.
Why the difference? Well, our first site is definitely more hospitable! Even we are happier to work here. It’s not nearly as hot, and the dune structure is more flat, so the breeze off the lake makes things more pleasant—for plants and people alike! And it appears to this observer’s eye that there’s more water available close to the surface here. This year, there are two large patches in the dune that have been perpetually damp. In contrast, our second population is literally high and dry, making life hard for the little pitcher’s thistle seedlings. How does this affect the prospects of these two populations overall? Stay tuned! We’ll let you know when we have finished our analysis of the long-term trends at these two very different sites.
One plant, two places—offering a fascinating glimpse of a life of contrasts.
Last year, with great anticipation, I became a plant sleuth. Tired of my relative ignorance of plants, I wanted to learn more about them and become more productive while being outdoors, which I am—a lot. So I joined Plants of Concern as a volunteer.
Based at the Chicago Botanic Garden, Plants of Concern (POC) was launched in 2001 by the Garden and Audubon–Chicago Region, supported by Chicago Wilderness funding. The program brings together trained volunteers, public and private land managers, and scientists, with the support of federal, state, and local agencies. For more than 15 years, the POC volunteers—a generally mild-mannered but formidable force of citizen scientists—have monitored rare, threatened, and endangered plant populations in our region to assess long-term trends.
On this foray with Plants of Concern, we flagged and counted targeted plants.
Broadly speaking, the data we plant detectives collect provides valuable information. Land managers and owners can use it to thoughtfully and effectively manage land, protecting ecosystems that have helped to support us humans. Scientists and students can use the data to help them understand rare-species ecology, population genetics, and restoration dynamics. The implications are significant, with climate change an important factor to consider in altered or shifting plant populations.
I quickly discovered that many POC volunteers are way more plant savvy than I am. Fortunately for me, the organization welcomes people of all knowledge levels. Our goal is to gather information about specific plant populations, ultimately to protect them against the forces of invasive plant species and encroaching urbanization. And our work is paying off. Some POC-monitored plant populations are expanding—reflected in the removal of those species from state lists of threatened and endangered species.
We are (mostly) unfazed
Yes, we POC volunteers are a hardy lot. Stinking hot, humid days on the sand dunes near Lake Michigan or the Midewin National Tallgrass Prairie? We drink some water and slap on sunscreen. Steep ravines with loose soil and little to hang onto? Bring it on! An obstacle course of spider webs? No prob—well actually, those are a real drag. Last time I wiped a web from my sweaty face I muttered, “There ought to be a word for the sounds people make when this happens.” (Oh, right, there is: swearing!) But webs slow us down for just a few seconds before we resume the business at hand.
Author’s note: Some projects are a little more involved than others. This was one of those.
That business is hunting down and noting targeted plants, and continuing to monitor them over time. Our tools are notebooks, cameras, and GPS mapping equipment. In northeast Illinois and northwest Indiana, we volunteers, along with Garden scientists and staff from partner agencies, have monitored 288 species across 1,170 plant populations at more than 300 sites, from moist flatwoods to dry gravel prairies to lakefront beaches and sand savannahs. Collectively, since Plants of Concern began, we have contributed 23,000 hours of our time in both the field and office.
“Northeastern Illinois is incredibly biodiverse, and some people are surprised to learn that,” says Rachel Goad, who became manager of the program in 2014, after earning a master’s degree in plant biology from Southern Illinois University–Carbondale. “There are so many interesting plant communities and lots of really neat plants. For people who want to learn more about them and contribute to their conservation, Plants of Concern is a great way to do that. We rely on interested and passionate volunteers—we would not at all be able to cover the area of the Chicago Wilderness region without them.”
From the minute I met up with a POC group during my first foray last October at Illinois Beach State Park, I was hooked. Though I often feel like a dunderhead as I bumble around hunting for my assigned plants, wondering why so many plants look so much like other plants, I love it. One reason is the other, more experienced volunteers and staff leaders, who generously help me as I ask question after question after question.
Plants of Concern foray leader Jason Miller: a man of ultimate patience—with me.
Some of us volunteers are walking plant encyclopedias, while others (that would be me) have been known to call out, “Here’s a dwarf honeysuckle!” only to have foray leader Jason Miller, patience personified, respond gently, “Actually, that’s an ash seedling.”
“Hey Jason,” I say a couple of weeks later, trying to look unconcerned. “Do you guys ever fire volunteers?”
“Yes, but it’s rare,” he replies. “Of more than 800 volunteers over all the years, maybe five at most—and not recently—were dropped from the program.” He indicates that it’s more a mismatch of interests than a few flubbed newbie I.D.s that can lead to that very rare parting of ways. Miller also acknowledges that some plants are especially tricky, such as sedges (Carex spp.) and dwarf honeysuckle (Diervilla lonicera). “Some species are straightforward,” he says, “and others are harder to monitor.”
I’m not hopeless—I’m just growing
I decide to interpret my POC foibles as “opportunities for growth,” since slowly but surely, I am starting to catch on. The information sheets distributed as we gather before a foray are making more sense to me. I am getting better at noticing the tiny serrated edges of a leaf, or compound rather than simple umbels, or any number of other subtle ways plants may distinguish themselves from others.
That gradual but steady learning curve fits with what Goad describes as “the most critical characteristic we look for in volunteers: someone who really wants to learn.” She adds that diversity among POC volunteers strengthens the program as a whole, helping to build a “constituency for conservation” among people not traditionally associated with environmental activism.
Volunteers get a debriefing before heading out on a foray. Newbies go with experienced volunteers.
Goad and her staff, which includes research assistants Miller, Kimberly Elsenbroek, and Morgan Conley, work to match volunteers with something that fits their level of expertise. This “hyper-individualized” approach to training POC volunteers can limit the number of participants per year, currently about 150 (a year-end tally firms up that number). “We tend to fill up our new volunteer training workshops, which means that our staff is always working at capacity to get those folks up and running,” says Goad. “I encourage people to sign up early if they know they are interested.”
Another challenge for managing the volunteer program, Goad adds, is that “any time you have a whole bunch of different people collecting and sending in data, there has to be a really good process for checking it and cleaning it and making it useful.” Over the years, the program has improved its volunteer training and data processing so that errors are minimized.
Get ready, get set—learn!
Miller was majoring in environmental studies at McKendree University when he came to POC in 2013 as an intern. Now, among other things, he’s in charge of volunteers at the Openlands Lakeshore Preserve. Like Goad, he says the main requirement in a volunteer is a willingness to learn. “We want someone who is interested in plants and their habitats,” he said. “If so, whenever you can help us out, great! We realize you’re giving your time to do this.”
Goad hopes to expand POC into other parts of Illinois over the next decade. “There are populations across the state that should be visited more regularly,” she says. “We do a lot with the resources we have, but it would be great to expand, and to do so, we need to continue to be creative about funding.” With partners that include forest preserve districts, county conservation districts, many land trusts, and nonprofit agencies that own land—and with its knowledge about challenged plant populations—POC is uniquely positioned to help facilitate collaboration.
The world’s best volunteer group
Whatever the time frame, wherever Plants of Concern volunteers are found, the hunt is on. Some days are glorious for us plant sleuths, such as my first foray last fall. We hiked over the dunes, Lake Michigan sparkling beside us, the cloudless sky brilliant blue. A light breeze kept us cool as we spread out, flagging the targeted plant—the endangered dune willow (Salix syrticola)—which was readily apparent and accessible. Then there are days like one this past June, when the sun beat down over a hazy Lake Michigan, humidity and temperatures soared, and my assignment was a steep, prolonged scramble over ravines to find and flag my elusive target, the common juniper (Juniperus communis). By the end of it I was, to coin a phrase, literally a hot mess—but a happy and triumphant one, for I had indeed been able to plant a few flags.
Perhaps it’s time for you to sleuth around and plant a few flags, too! Visit Plants of Concern and find out how to join.
Plants of Concern is made possible with support from the U.S. Department of Agriculture Forest Service at Midewin National Tallgrass Prairie, Forest Preserves of Cook County, Openlands, Nature Conservancy Volunteer Stewardship Network, National Fish and Wildlife Foundation, and Chicago Park District.
The National Parks provide dream vacations for us nature lovers, but did you know they also serve as vital locations for forward-thinking conservation research by Chicago Botanic Garden scientists?
From sand to sea, the parks are a celebration of America’s diversity of plants, animals, and fungi, according to the Garden’s Chief Scientist Greg Mueller, Ph.D., who has worked in several parks throughout his career.
“National Parks were usually selected because they are areas of important biodiversity,” Dr. Mueller explained, “and they’ve been appropriately managed and looked after for up to 100 years. Often times they are the best place to do our work.”
As we celebrate this centennial year, he and his colleagues share recent and favorite work experiences with the parks.
Dr. Greg Mueller working at Big Thicket National Preserve, Texas, in 2007.
Take a glimpse into the wilderness from their eyes.
This summer, Mueller made a routine visit to Indiana Dunes National Lakeshore to examine the impact of pollution and other human-caused disturbances on the sensitive mushroom species and communities associated with trees. “One of the foci of our whole research program (at the Garden) is looking at that juxtaposition of humans and nature and how that can coexist. The Dunes National Lakeshore is just a great place to do that,” he explained, as it is unusually close to roads and industry.
Evelyn Williams, Ph.D., adjunct conservation scientist, relied on her fieldwork in Guadalupe Mountains National Park to study one of only two known populations of Lepidospartum burgessii, a rare gypsophile shrub, during a postdoctoral research appointment at the Garden. “We were able to work with park staff to study the species and make recommendations for management,” she said.
Dr. Evelyn Williams in Guadalupe Mountains National Park during 2014 field work. Photo by Adrienne Basey.
As a Conservation Land Management intern, Coleman Minney surveyed for the federally endangered Ptilimnium nodosum at the Chesapeake and Ohio Canal National Historical Park earlier this year. “The continued monitoring of this plant is important because its habitat is very susceptible to invasion from non-native plants,” explained Minney, who found the first natural population of the species on the main stem of the Potomac River in 20 years.
Harperella (Ptilimnium nodosum) grows on scour bars of rivers and streams. Photo by Coleman Minney.
According to conservation scientist Andrea Kramer, Ph.D., “In many cases, National Parks provide the best and most intact examples of native plant communities in the country, and by studying them we can learn more about how to restore damaged or destroyed plant communities to support the people and wildlife that depend upon them.”
The parks have been a critical site for her work throughout her career. Initially, “I relied on the parks as sites for fieldwork on how wildflowers adapt to their local environment.”
Today, she is evaluating the results of restoration at sites in the Colorado Plateau by looking at data provided by collaborators. Her data covers areas that include Grand Canyon National Park, Capitol Reef National Park, and Canyon de Chelly National Monument.
Along with colleague Nora Talkington, a recent master’s degree graduate from the Garden’s program in plant biology and conservation who is now a botanist for the Navajo Nation, Dr. Kramer expects the results will inform future restoration work.
Dr. Kramer collects material from Arches National Park as a part of her dissertation research in 2003.
At Wrangell–St. Elias National Park and Preserve in Alaska, Natalie Balkam, a Conservation Land Management intern, has been hard at work collecting data on vegetation in the park and learning more about the intersection of people, science, and nature. “My time with the National Park Service has exposed me to the vastly interesting and complex mechanics of preserving and protecting a natural space,” she said. “And I get to work in one of the most beautiful places in the world—Alaska!”
The view from survey work in Elodea, part of the Wrangell–St. Elias National Park Preserve in Alaska. Photo courtesy National Park Service.
The benefits of conducting research with the National Parks extend beyond the ability to gather high-quality information, said Mueller. Parks retain records of research underway by others and facilitate collaborations between scientists. They may also provide previous research records to enhance a specific project. Their connections to research are tight. But nothing is as important as their ability to connect people with nature, said Mueller. “That need for experiencing nature, experiencing wilderness is something that’s critical for humankind.”
For research and recreation, we look forward to the next 100 years.
Experts in reforestation are concerned with the reasons why some replanted sites struggle. They suspect the problem may be solved through soil science.
The health of a forest is rooted in soil and the diverse fungi living within it, according to researchers at the Chicago Botanic Garden, Northwestern University, and collaborators at China’s Central South University of Forestry and Technology.
In densely populated places such as the Chicago area and Changsha, the capitol of the Hunan province, ongoing development and urban expansion frequently lead to the deforestation of native natural areas.
Research collaborators tour a study site in China.
“There has been a lot of deforestation in China and so there is interest in knowing how best to do reforestation, whether we’re using native plants or introduced plants in plantation settings,” explained Greg Mueller, Ph.D., chief scientist at the Garden. “Understanding who the players are both above ground and below ground helps us understand the health and sustainability of that above-ground plant community,” he added. “It’s analogous to restoration work being carried out here in the Midwest.” The climate, he explained, is similar in Changsha and Chicago.
A wide variety of fungi live in a symbiotic partnership with roots of trees everywhere. These fungi and trees are involved in a vital exchange of goods. The fungi deliver water and nutrients to the trees, and in return take sugars the trees produce during photosynthesis. Without this symbiotic relationship, the system would fail.
Not all tree species and fungi can team up for success, according to Dr. Mueller, who explained that it is essential for the partners to be correct if the tree is to survive. “The wrong fungi may actually be more pathogenic than beneficial,” he explained. Mueller is guiding research on this delicate soil-tree relationship as conducted by his doctoral student Chen Ning.
Ning is on leave from his position as a lecturer at Central South University of Forestry and Technology while he completes his studies with the Garden and Northwestern University. However, much of his work is taking place in China, where he has just completed the first phase of fieldwork.
After completing his master’s degree, Ning was keenly aware of the important role fungi play in the health of the natural world. He knew that he “wanted to ask some questions about the environment and how fungi influence the environment.” He added with a smile, “that’s why I chose to do some dirty work in the soil.”
Chen Ning stands behind Dr. Greg Mueller and collaborating professors.
The bright scientist is using the latest technology available, next-generation sequencing, to examine the molecular composition of soil samples taken from locations where native or nonnative trees or both were replanted 30 or 40 years ago. Specifically, he is looking at the replanting of Mason pines, a native Chinese pine, and slash pine (Pinus ellitottii), a nonnative pine introduced to China from the tropical state of Florida.
Ning recently completed his first review of those samples, finding large numbers of fungi in each. In addition, he found that the three different habitats have very different fungal communities.
Mueller and Ning visited the university and collaborators in Changsha in February. Mueller was able to visit the sites Ning sampled during the first phase of research and see the setup for the second phase of research in the greenhouses. The level of disturbance in the natural areas was extensive, a point of interest for Mueller who said, “that again makes it interesting to look at some ecological questions about disturbance and how that impacts these systems.” The team also had time to discuss the importance of considering fungi in related research initiatives.
Taking a break for a selfie and some sightseeing
Next up, Ning will examine his greenhouse plantings that use soils taken from his different field sites to determine if the fungi community changes in response to what type of tree is planted. When that is complete at the end of this summer, Ning will look at the enzyme activity in the soil to determine if fungi are functioning differently in the three different plantings (native forest, native tree in plantation, exotic tree in plantation). The study is on a fast track with a targeted completion date in late 2017 and is expected to add new understandings to the biology of plant-fungal relationships while generating important information on reforesting disturbed sites in south-central China.
After completing his Ph.D., Ning hopes to work as a professor to inspire students in China to pursue similar research. He also aspires to serve as a bridge between the United States and China for new research collaborations on topics such as climate change in order to help figure out the ‘big picture’ in the future.
To most people, the word “pollinator” is synonymous with the word “bee,” but only a fraction of plants are pollinated by bees.
In fact, manydifferent insects and mammals are pollinators—bats, birds, beetles, moths, and more. As part of National Moth Week, we wanted to highlight our work on a very special group of moths: the Sphingidae, or hawkmoths, which pollinate more than 106 plant species in North America alone, and many more around the world.
A newly emerged Hyles lineata hawkmoth
I am a research tech in the Skogen lab. I work with Krissa Skogen, Ph.D., her postdocs Tania Jogesh and Rick Overson, and fellow Garden scientist Jeremie Fant, Ph.D., on a National Science Foundation Dimensions of Biodiversity project entitled, “Landscapes of Linalool: Scent-Mediated Diversification of Flowers and Moths across Western North America.” Our project looks at floral scent and pollination in the evening primrose (Onagraceae) family.
Many species in the evening primrose family are pollinated by the white-lined hawkmoth (Hyles lineata). This pollinator is also an important herbivore! Female moths lay eggs on evening primroses, and their hungry caterpillars feed on the leaves, buds, and flowers. How does scent play a role in attracting hawkmoths? Do moths use it for pollination? Or do they use it to find host plants to lay their eggs? Or maybe both?
Hawkmoth pupae (Hyles lineata)
Hyles lineata eggs on an Oenothera harringtonii plant
From Dr. Skogen’s prior research, we know that floral scent can vary within and between plant populations. For instance, within the species O. harringtonii, some populations produce a scent compound called linalool while others do not. We think that the plants face a signaling dilemma: How do they use floral scent to invite their pollinators and yet avoid getting eaten? If female moths use linalool to lay eggs, then perhaps, in some populations, the plants benefit from not advertising their scent. To test this idea, we needed to conduct behavioral experiments to understand how Hyles perceive floral scent
This summer, along with Victoria Luizzi, a summer REU student from Amherst College, we looked at which plants female moths prefer to lay their eggs on—plants from populations containing linalool, or plants from populations without linalool. To answer this question, we first went to Colorado (where the plants naturally grow) and got plants from two different populations, one population that we know produces linalool and another we know doesn’t. Meanwhile our collaborator, Rob Raguso at Cornell University, sent us hawkmoth pupae and we patiently waited for them to emerge.
Victoria Luizzi (left) and Andrea Gruver (right) dissect a female moth to count remaining eggs.
When the moths emerged they were placed in mating cages. Once mating occurred, females were transferred to a quonset in the evening that contained four plants from the linalool population and four plants from the non-linalool population. The moths were left overnight so the females had plenty of time to choose where they wanted to lay their eggs. The next morning, Victoria counted the eggs on each plant (which was sometimes hundreds!) to see on which plants the females were choosing to lay their eggs. In addition, we dissected each moth to see how many eggs the female did not lay.
Krissa Skogen moves a moth to its new enclosure in her office
Over the course of the project, 12 females were flown in the quonset. Overall, the moths showed a preference for plants from the population that produces linalool. These data suggest that plants risk inviting foes while advertising to their friends—but we’ll need to collect a lot more data to be certain. Ultimately, both the insects that pollinate flowers as well as the insects that eat them might determine how a flower smells! We hope to continue this study to test our hypothesis further and learn more about how scent influences hawkmoth behavior, and how hawkmoth behavior influences floral scent and other floral traits of the plants they pollinate.
