plant conservation – Page 6 – My Chicago Botanic Garden

Treasure in the Tropics

Hungry for progress, Nyree Zerega, Ph.D., set off in early June to the forests of Sabah, Malaysia, on the island of Borneo. She was searching for plants in the genus Artocarpus, whose nearly 70 species include jackfruit—the world’s largest tree-borne fruit structure.

Her mission? To gather detailed information about species within the genus, including those that could provide food in tropical areas where it is needed most.

PHOTO: Dr. Zerega and Dr. Joan Pereira climbing hill in tropical forest. — Dr. Zerega in Sabah with Dr. Joan Pereira, her Malaysian collaborator.

On their research trip this summer, Dr. Zerega, a plant evolutionary biologist at the Chicago Botanic Garden, and her research team crossed a small stream on their way into a tropical forest on the edge of a large oil palm plantation. They searched there for an uncommon species until sunlight faded and the light rain turned to a downpour. On the way back, they found that the stream had grown into a raging river several feet wide and deep. Covered in leeches, they held hands tightly and waded across to safety. On other days, they searched for species with leaves as tall as any one of them, and collected fruit weighing more than 20 pounds apiece.

The dish

It’s all in a day’s work for Zerega. She has long traveled to places like this, where she works closely with local scientists to study underutilized food-bearing plants.

PHOTO: Jeisn Jumian with a huge jackfruit over one shoulder, and a cut jackfruit in his other arm. — Jeisn Jumian, field assistant, carries jackfruit back from the field for dinner.

Currently, she explained, the world relies on roughly 30 species to provide the majority of our food. The top three crops—rice, corn, and wheat—account for approximately 40 percent of all food consumed worldwide. We are merely scratching the surface of the thousands of edible plant species in existence, including at least a dozen in the genus Artocarpus.

It’s possible, even likely, that some underutilized crops have as much potential as the current favorites, but simply have not been as developed. “Underutilized crops have the potential to diversify the world’s food supply and improve food security,” said Zerega. She believes the development of these crops, produced close to where they would be consumed, could also reduce the amount of energy used in growing and exporting large quantities of crops around the world. The more options we have, the better off we are, she maintains.

Stocking the pantry

Now back in the Harris Family Foundation Plant Genetics Laboratory of the Daniel F. and Ada L. Rice Plant Conservation Science Center, Zerega and her lab members are busy extracting plant DNA from leaves collected in Malaysia. Also the director of the Northwestern University and Chicago Botanic Garden Graduate Program in Plant Biology and Conservation, she has plenty of helping hands from her master’s and doctoral students.

“We’ll be studying DNA to understand the evolution of Artocarpus, and patterns of the diversity of cultivated members of the genus, such as jackfruit, breadfruit, and the lesser known cempedak, a species believed to have originated in Malaysia. Understanding and conserving genetic diversity is as critical in crop species as it is in wild species,” she said.

PHOTO: The market in Sabah, Malaysia. — Breadfruit is sold at a market in Sabah, Malaysia.

The work is part of a National Science Foundation grant for which Zerega is assembling a taxonomic revision, which is like a genealogical history. It will include descriptions of all the Artocarpus species, how to identify them, where they originated, where they are found today, how they are used, and how they are related to one another.

Dried, pressed specimens of all the plant samples used for DNA will be stored in herbaria in Malaysia and the Garden’s Nancy Poole Rich Herbarium. Zerega serves as director of the herbarium. These specimens, along with photographs, serve as documentation of each plant.

Cooking up solutions

PHOTO: A plate of fried breadfruit with dipping sauce. — Fried breadfruit from a market near Kuala Lumpur, Malaysia.

Next, Zerega hopes “to focus on ways to conserve the diversity and increase the use of underutilized species such as jackfruit and breadfruit, because they hold great potential for increasing food security in food-insecure parts of the world, many of them in tropical areas where Artocarpus species grow.”

As she considers her research, Zerega occasionally finds time to stroll her favorite areas of the Garden—the Dixon Prairie and the McDonald Woods.

From working with students and collaborating with scientists around the world, she hopes her work will contribute to the conservation of underutilized crop diversity and food security around the world. Although she has already accomplished a great deal, it seems that Zerega’s work so far is just a taste of what is to come.

Read more about Zerega’s research in Papua New Guinea, the Northern Mariana Islands, Hawaii, and Bangladesh in the Spring 2013 issue of Keep Growing.

The Evolution of a Research Idea

Five years ago this past May, I found myself starting a new job and a new research project. My job, of course, was as a conservation scientist here at the Chicago Botanic Garden, and the research project had me sitting on the side of a road at dusk in Pueblo West, Colorado. I sat there in front of a group of plants that produce lovely-smelling flowers, waiting for their impressive pollinators to show up. And when they did, I snapped some of my very first photos of these beauties: hawkmoths, better known as the five-spotted hawkmoth, or to the scientific community as Manduca quinquemaculata.

PHOTO: Night photo of hawkmoth sipping nectar from evening primrose. — A five-spotted hawkmoth (*Manduca quinquemaculata*) drinks nectar from the Colorado Springs evening primrose (*Oenothera harringtonii*) as the flower begins to open. Pueblo West, Colorado, May 2008. Photo: Krissa Skogen

Just this past Friday, I visited the National Science Foundation’s Dimensions of Biodiversity Program, to find this very same photo—and the research that my colleagues and I will conduct over the next five years—highlighted.

So how did this one photo go from being taken in the spring of 2008 to being highlighted on the NSF’s website? How does a research project evolve and grow over time? Ask any scientist what they are currently working on and their answer will almost always start with, “I was first fascinated by x back in y….” Something caught their attention, sparked a thought, pulled them in—and they continued asking question after question, developing hypotheses and gathering data to test them, with their answers pushing them forward, sometimes down unanticipated paths, and sometimes into much bigger or smaller arenas. The more one knows, seemingly, the less one knows; old questions are answered and new ones are developed. This is what pushes scientists, and science, forward.

The evolution of a research idea

PHOTO: Krissa Skogen poses with primrose in New Mexico. — Krissa Skogen poses with an evening primrose in New Mexico. Photo: Chris Martine

In 2008, I started my current research program. After many conversations with Rob Raguso (Cornell University) and Tass Kelso (Colorado College), I drove out to Colorado with a plan to collect as much information on as many different populations of the Colorado Springs evening primrose (Oenothera harringtonii) as possible in a short period of time. That year, my timing was off—I arrived in Colorado on June 10. Oenothera harringtonii flowers primarily in May. Most of the plants had stopped flowering and so instead of collecting data on floral features, nectar, scent, and pollinators, my field assistant, Evan Hilpman, and I collected data on plant size, health, reproductive success (how many fruits did they produce?) and population size (much like a census). And one striking thing we noticed was this: small white “galls” on some of the green, developing fruits. We took notes on how often we saw this, never anticipating the importance that these little white dots would play in just a few years’ time.

PHOTO: Closeup image of a tiny, white foamy-looking dot (one of many) on a host plant. — We noticed small white “galls” on some of the green, developing fruits. These are parts of the cocoons of tiny little moths, called microlepidopterans, of the genus *Mompha*. Photo: Krissa Skogen

In subsequent years this project grew, and in the last four years—with the help of conservation scientist Jeremie Fant and other colleagues, and many research assistants and students—we’ve collected data on flower size, nectar volume and sugar content, floral scent, who pollinates and when (hawkmoths come at dusk and visit overnight; bees generally visit in the morning), how populations grow and shrink over time, which other plant species are flowering at the same time, and more. We know a lot of things about this species now, and one thing has been a constant: those little white balls have been observed year-in and year-out in some populations, but not in others.

We know now that some of our populations have an important compound—linalool—and some do not. We know that genetically speaking, our 25 populations function more like three, likely due to the fact that hawkmoths can fly so darn far (some estimates are up to 20 miles in just one night). And more recently, we started gathering more data on those little white balls. It turns out that they are parts of the cocoons that surround the larvae of tiny little moths called microlepidopterans, which belong to the genus Mompha. These moths lay their eggs on flower buds, fruit, and stems. If the larvae eat flower buds and/or seeds, they reduce the number of offspring that the plant produces. This is bad for any plants upon which these moths decide to lay their eggs, but everything must eat, right?

PHOTO: Trio of photos of each life stage of the moth: adult, larva, and cocoon. — *Mompha stellella* microlepidopteran adult; larva inside fruit (seed predator); cocoon inside *O. harringtonii* fruit. Photos: Terry Harrison and Krissa Skogen

In speaking with colleagues across the country and in Canada (plant and moth experts, alike), we developed an intriguing story and series of hypotheses we felt were compelling. Do pollinators and floral antagonists both respond to the same attractive scent? Could floral scent be telling hawkmoths and Mompha moths where the flowers are? Pollination is good for plant reproduction, but anything that eats flowers or seeds is not—so how would this trade-off play out in evolutionary time?

These questions have led us to the project that we will pursue on a much larger scale, thanks to recently awarded funding from the National Science Foundation’s Dimensions of Biodiversity Program for our proposal, titled “Landscapes of linalool: scent-mediated diversification of flowers and moths across western North America.”

PHOTO: Bee coated in pollen, inside primrose bloom. — A *Lasioglossum* species bee robbing pollen from *O. harringtonii* at dawn. Photo: Sadie Todd

Relationships among flowering plants and insects represent one of the great engines of terrestrial diversity. Floral scent and other plant volatiles are important drivers of these relationships (e.g., pollination, herbivory, plant defense), but remain poorly integrated into floral evolution and pollination ecology. Few studies have tested the spectrum of plant fitness outcomes when scent attracts both pollinators and floral/seed enemies. Thus, the hidden diversity of floral/seed predators and their potential as selective agents constitutes a considerable gap in pollinator-centric understanding of floral evolution. These “forgotten predators” have co-diversified with flowering plants and are likely influential in the evolution of most plant-pollinator interactions.

PHOTO: Five-spotted hawkmoth extending its proboscis (longer than its body) into a primrose bloom as it hovers. — A five-spotted hawkmoth (*Manduca quinquemaculata*) probes an opening evening primrose flower for nectar with its proboscis. Photo: Krissa Skogen

This project is ambitious and large and pulls upon a wide variety of expertise. In total, there are 11 Ph.D. scientists collaborating on it, including myself, Jeremie Fant, and Norm Wickett here at the Garden. The others include Robert Raguso (Cornell University), Rachel Levin (Amherst College), Terry Harrison (University of Illinois at Urbana-Champaign), Jean-Francois Landry (Agriculture & Agri-Food Canada, Eastern Cereal and Oilseed Research Centre), Sylvia (Tass) Kelso (Colorado College), Kathleen Kay (University of California, Santa Cruz), Mike Moore (Oberlin College), and Warren Wagner (Smithsonian Institution).

We are excited about what we’ll uncover in the next five years and will update you with progress as our discoveries unfold!

“Should we try to roll its tongue out?”

PHOTO: Sophia Siskel holds a hawkmoth caught at night while researchers look on. — Holding a toad-sized hawkmoth lured in by our sheet and black light.

O.K., I did know what a proboscis was before my trip to New Mexico last month. But learning how to uncoil a hawkmoth’s 3-inch nectar-sucking hollow tongue while trying to calm the toad-sized insect in my hand was the biology lesson of a lifetime.

Thanks to Chicago Botanic Garden scientists Krissa Skogen, Ph.D., and Wes Glisson (who recently earned his master’s degree in plant conservation biology from the Garden/Northwestern University graduate program), and Bureau of Land Management (BLM) New Mexico state botanist Mike Howard, I learned about hawkmoths, the plants they pollinate, and how to collect plant cuttings for scientific study.

I also had the opportunity to meet and work beside two remarkable interns, Kate Wilkins and Elisabeth Ward, from our Conservation Land Management Internship Program (and enjoy a few absolutely perfect hours of exquisite silence in the desert at the foot of the Guadalupe Mountains on the New Mexico/Texas border).

PHOTO: Panorama of the New Mexican desert. — The exquisite silence and panorama of the New Mexican desert.

I had been asking around the Garden’s scientific staff to see whose fieldwork would fit with my summer schedule. Krissa was planning a trip to southern New Mexico to film an episode of Chris Martine’s great video web series Plants are Cool, Too. Krissa’s episode, which will air in October, highlights her work on long-distance pollinator movement, focusing on Oenothera harringtonii, an evening primrose endemic to southeastern Colorado and other closely related Oenothera species. The flowers of Oenothera harringtonii and many other evening primroses open soon after sunset and are pollinated primarily by hawkmoths. These moths feed on the nectar of Oenothera flowers, which they locate by the strong fragrance produced by the flowers. We commonly think of floral scent for its role in attracting pollinators, but it may also be used as a cue by floral and seed predators.

By studying the shape, smell, and color of Oenothera flowers, Krissa and her colleagues hope to determine what it is that attracts pollinators to these flowers. She can also determine how the plants “reward” their pollinators by studying nectar—how much flowers produce and how much sugar the nectar contains. And lastly, by collecting pollen grains from pollinators, Krissa can determine which plant species the pollinators rely on most, which brings me to catching hawkmoths and collecting pollen from their tongues.

PHOTO: Krissa gently rolls out the proboscis to show us just how long it is! — Krissa gently rolls out the proboscis to show us just how long it is!

The first night of our trip, we set out to find some hawkmoths. After visiting a couple of sites in the Organ Mountains, we found them. Above is a photograph of Dr. Krissa Skogen, Elisabeth Ward, and me holding the toad-sized moths we attracted to a blacklit white sheet held up on a PVC armature.

After sunset, the hawkmoth uses its long hollow tongue to extract the nectar from deep down within the narrow mouth of the flower. The moth’s nightly journey often covers a distance as far as 20 miles. Krissa gently rolled out the tongue to show us just how long it is!

The next day, we set out early to collect Lepidospartum quamum for our colleague Evelyn Williams, Ph.D. Evelyn, a post-doctoral researcher, has been working with Jeremie Fant, Ph.D., Kayri Havens, Ph.D., and Mike Howard on this plant since 2012 in an attempt to figure out why it is threatened with extinction in this area of New Mexico. The plant grows in a unique environment—the gypsum salt flat.

PHOTO: Tagged plant cuttings in a small bowl. — *Lepidospartum quamum* cuttings, tagged and ready to be sent for propagation in our greenhouses.

Evelyn’s previous collecting trip this spring needed to be supplemented with new cuttings. We worked all day to collect the cuttings, which we sent back to the Garden for propagation in our production greenhouses, as well as samples for genotyping in the Garden’s Harris Family Foundation Plant Genetics Laboratory.

This important work, which ultimately aids seed growers, restoration practitioners, and government agencies to select appropriate plant materials to restore diverse plant and animal communities, was funded by a National Fish and Wildlife Foundation (NFWF) grant as part of the Native Plant Conservation Initiative.

It’s a fact that most people are more attracted to animals than plants—and therefore more inclined to know their names and fight for their survival. Just compare the following two photographs—the Lepidospartum quamum specimen we were studying, and this lizard that darted by and immediately commanded our attention (yes, even botanists and plant-lovers are drawn to a cute face).

PHOTO: A desiccated Lepidospartum quamum plant. — What grabs your attention more? This plant …

PHOTO: A cute lizard. — …or this cute lizard?

But all life depends on plants and the healthy habitats on which they depend. When we think of fighting to save wildlife, let’s remember that wildlife includes plants! I am hopeful that by working with collaborations from gardens, zoos, government agencies, and other land-trust and conservation organizations, we can integrate plants into wildlife action plans both in the U.S. and abroad. I particularly like how this report by NatureServe summarizes this issue.

We can all point to moments in our life—when we’ve experienced something new or met someone special—when our understanding of life changes. My two days with these five scientists—at all phases of their careers—was one of these experiences I will never forget.

PHOTO: The New Mexico research team. — Thank you, Krissa, Kate, Mike, Elisabeth, and Wes!

One last note: Hawkmoths are essential to ecosystems from Venezuela to here in Chicago. My son and I watched one this afternoon drink from the hostas on our street! Below is one we filmed in the English Oak Meadow of the Chicago Botanic Garden last week.

Painting with Numbers

Emily Yates has covered a lot of territory.

Once a summer intern who collected plant seeds in North Dakota, she now manages an innovative mapping laboratory at the Chicago Botanic Garden. A scientist and artist, Yates translates massive amounts of data into accurate, colorful depictions to help researchers communicate their findings. Scientists, land managers, volunteers, and others use this information to help advance collective conservation goals.

Her newest project was freshly completed when we met in her office at the Daniel F. and Ada L. Rice Plant Conservation Science Center. It’s a project that has set the pace for modeling the immense database of the Plants of Concern (POC) program, and is likely to garner much attention at upcoming scientific conferences.

PHOTO: Hill's thistle and wooly milkweed in the field. — Hill’s thistle (*Cirsium hillii*) and wooly milkweed (*Asclepias lanuginosa*) are two of the rare plants monitored by the Plants of Concern program. (Milkweed photo ©Carol Freeman)

POC volunteers are citizen scientists who use GPS, global positioning systems, to gather geospatial data marking the location of rare plants in the Chicago area. “Part of what Plants of Concern wants to do is monitor, over time, changes in all the populations that are known of these rare plants,” said Yates, Seed Bank coordinator and conservation GIS Laboratory manager at the Garden.

Why rare plants? They have such specific environmental requirements and occur so infrequently, that they could be entirely lost if conditions change.

In late August, Yates wrapped up several months of work with a team including an intern with the Garden’s Research Experience for Undergraduates (REU) program. Together, they mapped the potential presence of Hill’s thistle (Cirsium hillii) and wooly milkweed (Ascelpias lanuginosa) across six northeastern Illinois counties monitored by POC. The two species are only known to grow in habitats characteristic of gravel hill prairies. The map was created using ten years of data on these two species.

MAP: Rare gravel hill species site suitability map. — Yates created this map to show areas where Hill’s thistle and wooly milkweed could occur.

“Sometimes with ecological data it’s easier to see things visually and spatially rather than in table format, and maps help to do that,” said Yates.

A Trimble is used to collect and plot geographical data of plant populations.

Looking at factors such as required soil type and land cover, they plotted locations where the plants have already been documented and used models to predict where the plants may exist due to favorable conditions. “Because these plants are rare, sometimes it’s very likely there are populations we haven’t found yet, so these maps can be very helpful in determining where to look,” said Yates. “GIS helps narrow [data] down and concentrate resources—enabling better land management decisions.”

What next? The paper the team generated will serve as a model for mapping the hundreds of other species monitored by POC, and it could be shared broadly through conferences and other means. Already, it was presented at the conclusion of the REU program.

Also, the project served as a valuable learning opportunity for the REU intern, who worked on the project in the GIS Lab with Yates, and in the field where he confirmed data records alongside scientists. Yates mentored an intern last summer as well, and is already thinking of the possibilities for next year.

According to Yates, “a lot of students express an interest in doing GIS projects because it is a skill that can be applied to a lot of different fields. Its focus on spatial thinking couples well with ecology and plant science, and it is a great, practical job skill to have.”

After completing her graduate studies, Yates expanded her own work to include a specialty in GIS. “My first love is nature and plants,” she said. “I became interested in how to look at plants and the natural world in a spatial context. I like the idea of cartography used for visualizing ecological patterns because it helps you see the connections.”

Learn more about Yates’s work and watch a video.

Emily Yates in the field, gathering herbarium specimens.

Yates, who also teaches GIS and spatial analysis to students in the Northwestern University and Chicago Botanic Garden graduate program in plant biology and conservation, is already hard at work on her next project. She is creating the spatial component for a database of the Garden’s Dixon National Prairie Seed Bank, part of the National Seeds of Success program. “When you put the spatial component into [data], it kind of makes it come alive,” she said.

Summer isn’t all about work for Yates, who is also a gardener. It is the time of year when she most loves to visit the Regenstein Fruit & Vegetable Garden to find inspiration. When we talked in late August, she was already brimming with ideas for her garden next year. Surely, it won’t be long before she has it all mapped out.

Weevil Warriors

A bracelet of pink-and-cream blooms borders Lake Michigan at this time of year. Growing up from barren, sandy areas, Pitcher’s thistle (Cirsium pitcheri) is like an oasis for nearby insects looking for nectar.

Helpful pollinators visit the plants often, but not nearly enough to offset the damage of the predatory visitors, according to Garden scientists, who hope to tip the balance in order to save the federally threatened plant species. It all began in 1997, when Kay Havens, Ph.D., joined a team of researchers to reintroduce Pitcher’s thistle to Illinois Beach State Park. But she wondered why a reintroduction was needed for a normally sturdy group of plants.

PHOTO: Adult weevils on Pitcher’s thistle plants in Door County, Wisconsin — Adult weevils on Pitcher’s thistle plants in Door County, Wisconsin

“Thistles as a group are typically pretty successful, even weedy, and it’s unusual to have a native thistle that is so rare,” said Dr. Havens, Medard and Elizabeth Welch director of plant science and conservation at the Garden.

Along with her Garden colleague, Pati Vitt, Ph.D., she found the plant is especially susceptible to a species of weevil (Larinus planus) whose larvae feast on emerging seeds. Unfortunately, if a blooming thistle loses its seeds before they are dispersed, new plants cannot be started.

“We were the first to document the weevil in this threatened thistle,” said Havens. “If we don’t find a way to control it, the plant is further threatened with extinction.” This discovery was followed by the identification of a second, equally destructive weevil (Rhinocyllus conicus) in Indiana Dunes State Park.

“The weevils have become very widespread in Pitcher’s thistle and they cut the seed output by about half,” said Havens. Both insect species, she explained, are biocontrol weevils that were intentionally scattered in the area for years in an effort to control the invasive Canada thistle (Cirsium arvense). Now, the damaging insects are off the list of solutions for Canada thistle.

As we talked, it was clear that this rescue team is not willing to accept defeat from a 7-millimeter bug. For years, they have been hard at work gathering information to help them arm the thistle against its adversary, and theorizing potential solutions.

Pitcher’s thistle lives four to eight years, and only blooms once, the conservation scientists told me. And they are also working to better understand the remarkable plant that has a custom set of strategies, like all plant species, to survive and reproduce.

“Every species represents a unique solution to an entire suite of environmental problems,” said Dr. Vitt, Susan and Roger Stone curator of the Dixon National Tallgrass Prairie Seed Bank at the Garden.

These solutions, she explained, could solve large-scale problems for people or other species in ways we don’t yet know. “The species has intrinsic value because it has these unique solutions that evolved over hundreds of thousands of years,” she added.

PHOTO: The research site in Wisconsin with flags marking study plants — The research site in Wisconsin with flags marking study plants

This summer, Havens and Vitt spent weeks in Door County, Wisconsin, observing the interactions of the weevil with Pitcher’s thistle, as well as those of its suite of pollinator species.

Watch a video to learn how Havens became interested in plants as a child, and why she says we couldn’t survive without them today.

Together with their research team, they recorded detailed notes about the frequency and time of visits by the helpful pollinators, like bees, and the dreaded weevils. In total, they monitored 27 visiting insect species.

“We want to find ways to protect this plant from weevils without affecting its pollinators,” said Havens. Could a certain floral scent do the trick? Could a natural insecticide be the answer? Each solution must be carefully tested and put to trial first.

For now, they are busy trying to understand the life cycle of the weevil as it relates to the thistle—from the time an adult lays its eggs in the seedhead to the time the larvae emerge from the flower and eat the seeds that could have been the next generation of plants.

As I left Havens and Vitt in the Daniel F. and Ada L. Rice Plant Conservation Science Center, they were sorting through their samples of seedheads and weevils, collected in the field, and musing over the potential solutions planted by their research that are just beginning to grow.