Julianne Beck – Page 3 – My Chicago Botanic Garden

Reforestation from the Ground Up

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.

Collaborators tour a study site in China. — 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.

PHOTO: Dr. Greg Mueller and Chinese collaborators. — 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.

On a Course for International Collaboration

As an active leader in international research collaborations, the Chicago Botanic Garden is participating in an initiative to set the stage for new partnerships.

Patrick Herendeen, Ph.D., senior director, systematics and evolutionary biology at the Garden, served as co-coordinator of “A Workshop to Explore Enhancing Collaboration Between U.S. and Chinese Researchers in Systematic Biology,” held in late February at the South China Botanical Garden in Guangzhou, China.

Funded by the U.S. National Science Foundation and Natural Science Foundation of China, the workshop brought systemicists from both countries together to explore research techniques and opportunities. (Systematics is the branch of biology that aims to understand the diversity of life and relationships among different groups of organisms, and spans subjects from plants and fungi to primates and viruses.)

Patrick Herendeen leads a discussion among systemisists from various fields.

“People bring different expertise to a research project, and people with different areas of expertise ask different questions or think about things differently,” explained Dr. Herendeen.

Greg Mueller, Ph.D., chief scientist at the Garden, also attended and spoke at the workshop. “There is an ongoing and increased interest in collaboration,” he said. “Chinese science is very mature…and China would be a great international collaborator.” In his presentation, Dr. Mueller addressed his experiences with international collaborations and offered advice to attendees.

Collaboration is key to scientific research. Diverse questions require multifaceted solutions. Often these approaches are best identified and pursued by a team of individuals with unique specialties, who at times may just happen to be sitting on opposite coasts of an ocean.

More than 60 scientists—about half from the United States and half from China—participated in two days of lectures, panels, and small group discussions. Speakers included Garden postdoctoral researcher, Fabiany Herrera, Ph.D., who discussed data and collections. Dr. Hererra works with his academic adviser, Herendeen, on a research initiative with partners in Japan, China, and Mongolia, in which they are studying plant fossils from the Early Cretaceous period.

Also in attendance was Chen Ning, a Ph.D. student in the joint degree program at the Garden and Northwestern University. Under the guidance of his adviser, Mueller, Dr. Ning is studying fungal communities in native pine forests and exotic pine plantations in south-central China.

One of the greatest takeaways of the conference, according to Mueller and Herendeen, was the opportunity for attendees to learn about the many similarities between the education and research systems in both countries. “We had very good discussions and everyone was very open about talking about how research works and the kinds of motivations that people have in the United States and China,” said Herendeen. “I think one of the things that surprised people were the similarities of the two programs. The systems are similar enough that it is possible to figure out how to do those collaborations,” added Mueller.

Workshop attendees also had an opportunity to participate in field trips to rural areas of Guangdong Province including Dinghushan and Heishiding Nature Reserve. They visited high-quality forested areas to discuss restoration work, seed banking, and related topics.

The workshop “gave everyone a chance to meet a lot of new people and talk about possible collaborations, and there were a number of new or potential new collaborative pairings or groups that formed as a result,” said Herendeen, who looks forward to continued—and new—collaborations.

A 20-Year Legacy of Conservation Conversations

For more than two decades, leaders in conservation science have come to the Chicago Botanic Garden each summer to discuss timely topics from monarch butterflies to assisted plant migration.

Butterfly on Liatris — Butterfly on *Liatris*

Seeds will be planted again on Monday, June 13, when regional stewardship professionals, academics, restoration volunteers, and interns gather for the Janet Meakin Poor Research Symposium. The annual day of lectures and discussions covers the latest findings in conservation research and best practices in restoration, while inspiring conversations and new partnerships.

“I think the science that pertains to land management is always evolving, and therefore best practices are always evolving,” said Kay Havens, Ph.D., Medard and Elizabeth Welch senior director, Ecology and Conservation, and the moderator of the symposium.

The 2015 symposium focused on restoration solutions for large-scale implementation, and this year’s theme, Seed Sourcing for Restoration in a Changing Climate, builds on the concept of seed management. “It focuses on conservation research and restoration and tries to make links with the land management community—so not just reporting the science but also reporting how that could influence land management,” explained Dr. Havens. This subject is especially timely, according to Havens, as it follows the first year of the National Seed Strategy for Rehabilitation and Restoration. The Garden has played a key role in establishing the seed strategy, which will create a network to ensure native seeds are available in restoration efforts, especially in fire-ravaged western rangelands.

“I think the need for restoration increases annually,” said Havens. “We are facing a more and more degraded planet every year, and as the climate changes and natural disasters like hurricanes and floods increase, the need for restoration increases.”

Read more about the symposium or register online for Seed Sourcing for Restoration in a Changing Climate today.

Evening Primroses, Pumps, and Pollinators

Rick Overson is fascinated with insects—especially the kinds that love desert climates like in Arizona, where he grew up and earned his Ph.D. in biology. After completing a postdoctoral assignment in northern California, he decided it was time to get to know the little buggers even better, so Dr. Overson hopped on a plane for Chicago and stepped out into the subzero temperatures of the polar vortex to do just that.

PHOTO: Dr. Rick Overson with hawkmoth specimens. — Dr. Rick Overson with hawkmoth specimens

The devoted entomologist didn’t expect to see the insects in Chicago, but he was eager to join research at the Chicago Botanic Garden. A multidisciplinary team was assembling there to look for scent variations within Onagraceae, the evening primrose family, and connections from floral scent to insect pollinators and predators. The findings could answer questions about the ecology and evolution of all insects and plants involved. Overson is a postdoctoral researcher for the initiative, along with Tania Jogesh, Ph.D.

“Landscapes of Linalool: Scent-Mediated Diversification of Flowers and Moths across Western North America” is funded by a $1.54 million Dimensions in Biodiversity grant from the National Science Foundation. The project is headed by Garden scientists Krissa Skogen, Ph.D., Norman Wickett, Ph.D., and Jeremie Fant, Ph.D. It was developed from prior research conducted by Dr. Skogen on scent variation among Oenothera harringtonii plants in southern Colorado.

“For me, the most important thing coming out of this project is documenting and showing this incredible diversity that happens inside a species,” said Overson. “It’s vitally important for me to break down this idea of a species as a discrete unit. It’s a dynamic thing that is different in one place than another. That factors into conservation and our understanding of evolution.” In this case, he and his colleagues theorize that the evolution of the insect pollinators and predators is connected to the evolution of the scent of the plants.

The first two years of field work brought Overson back to his desert home. He traveled across Arizona, Utah, and nearby states with a group of about five scientists during summer months when the flowers were blooming. The team visited several populations each of 16 species of flower for a total of 60 locations. Overson and the team identified and documented the insects visiting the plants and compiled scent chemistry from the flowers. Their tool kit included a pump to pull the scent from a flower onto tiny polymer beads that held the scent inside of a vial. From there, they extracted the scent chemicals at the end of the research day or night. “It’s definitely the case that this pattern of scent variation inside a species is very common in this group,” he said of the team’s preliminary findings.

PHOTO: Hawkmoth on evening primrose. — A beneficial pollinator, the hawkmoth, visits an evening primrose (*Oenothera harringtonii*).

In the field they also took video recordings of pollinator behavior to see who visited which flowers and when. The pollinators, including hawkmoths and bees, follow scents to find various rewards such as pollen or nectar. The insects are selective, and make unique choices on which plants to visit.

Why do specific pollinators visit specific plants? In this case, the Skogen Lab is finding that it is in response to the scent, or chemical communication, each flower releases. “In the natural world those [scents] are signals, they are messages. Those different compounds that flowers are producing, a lot of them are cocktails of different types of chemicals. They could be saying very different things.”

PHOTO: Closeup of a wasp on a closed evening primrose bloom. — Nature is complicated. Here, a wasp lays eggs through a flower bud into a hidden Mompha moth inside. Its larvae will eventually destroy both the moth and the flower. Photo by Dr. Rick Overson

A destructive micromoth called a microlepidopteran (classified in the genus Mompha), has also likely learned how to read the scent messages of its hosts. The specialist herbivore lays eggs on plants leading to detrimental effects for seed production. The team’s field work has shown that Mompha moths only infect some populations of flowers. When and why did the flowers evolve to deter or attract all of these different pollinators? Or was it the pollinators who drove change?

At the Garden, Overson is currently focused on exploring the genomes, or DNA set, of these plants to create a phylogeny, which looks like a flow chart and reads like a story of evolution. “Right now we don’t know how all of these species are interrelated,” he explained. When the phylogeny is complete, they will have a more comprehensive outline of key relationships and timing than ever before. That information will allow scientists to determine where specific scents and other traits originated and spread. He will explore the evolution of important plant traits using the phylogeny including the color of the flowers and their pollinators, to answer as many questions as possible about relationships and linked evolutionary events.

In addition, the team is looking at population genetics so they can determine the amount of breeding occurring between plant locations by either seed movement or by pollinators. They will also look for obstacles to breeding, such as interference by mountain ranges or cities.

“Relationships among flowering plants and insects represent one of the great engines of terrestrial diversity,” wrote principal investigator Krissa Skogen, PhD, in a blog post announcing the grant.

The way that genes have flowed through different populations, or have been blocked from doing so over time, can also lead to changes in a species that are significant enough to drive speciation, or the development of new species, said Overson. “The big idea is that maybe these patterns that are driving diversity within these flowers could ultimately be leading to speciation.”

By understanding these differences and patterns, the scientists may influence conservation decisions, such as what locations are most in need of protection, and what corridors of gene flow are most important to safeguard.

PHOTO: Dr. Rick Overson in the field. — Dr. Rick Overson in the field

“We absolutely can’t live without plants or insects, it’s impossible,” remarked Overson. “Plants and insects are dominant forces in our terrestrial existence. Very few people would argue that we haven’t heavily modified the landscape where these plants and insects live. I think it is crucially important to understand these interactions for the sake of the natural world, agriculture and beyond.”

When Dr. Overson is taking a break from the laboratory, he visits the Desert Greenhouse in the Regenstein Center, which feels like home to him.

How Love and Science May Defend a Wild Orchid

Life on the prairie hasn’t been a breeze for the beautiful eastern prairie fringed orchid (Platanthera leucophaea).

Once common across the Midwest and Canada, the enchanting wildflower caught the attention of collectors and was overharvested throughout the 1900s. At the same time, large portions of its wet prairie, sedge meadow, and wetland habitat were converted to agriculture. By 1989, just 20 percent of the original population of Platanthera leucophaea remained, and the orchid was added to the federally threatened species list.

PHOTO: Claire Ellwanger takes a leaf sample in the field. — Claire Ellwanger takes a leaf sample in the field.

The struggles of the captivating orchid did not go unnoticed. Its lacey white flowers and unique biological attributes sparked a passion in scientists and volunteers across the Midwest who began gathering leaf samples for genetic analysis and recording measurements on the health of certain populations. Some volunteers dedicated decades to this work, and many continue to monitor their assigned location today.

As long ago as the mid 1800s, an earlier generation of the wildflower’s enthusiasts had preserved samples of actual plants, pressing them onto archival paper with their field notes and placing them in long-term storage facilities called herbaria, for future reference. As it turns out, some of the plant materials they saved are from populations that no longer exist.

Now, all of that data is coming together for the first time in a research study by graduate student Claire Ellwanger.

The master’s degree candidate—in a Plant Biology and Conservation graduate program run by the Chicago Botanic Garden and Northwestern University—is using modern analysis tools to uncover the genetic history of the species. What she finds will give scientists a better picture of the present-day status of genetic diversity of the species, and insight into the best ways to manage it for the future.

PHOTO: Clarie Ellwanger measures orchid seed pods in the field. — Claire Ellwanger measures orchid seed pods in the field.

“This orchid is a pretty interesting species because there has been this massive volunteer effort for over 20 years to restore it in Illinois,” noted Ellwanger, who said that Illinois currently houses more populations, or locations, of the species than any other state.

She is focused on collecting and analyzing genetic information on the remaining plants, working with field collectors in the Midwest from Iowa to Ohio, and also from Maine. She is examining the genes, or DNA, of each of the sampled populations, along with genetic information she collected at eight sites right here in Illinois.

Ellwanger is also extracting DNA from the older herbarium samples to better understand how much genetic diversity was a part of the species in the past. “The herbarium samples will allow us to get a sense of historic genetic variation to compare to levels today,” she explained.

Along with her thesis advisor, Garden molecular ecologist Jeremie Fant, Ph.D., she is especially interested in finding ways to maintain genetic diversity. “We know that if you are able to preserve the most genetic diversity in a species, it is more likely to persist for longer,” she explained.

PHOTO: Extracted DNA is ready for analysis in the laboratory. — Extracted DNA is ready for analysis in the laboratory.

In the lab today with her research assistant, Laura Steger, she uses a genetic fingerprinting technique on all groups in her study subjects. By watching the same sequence of genes over time and locations, she can see clear patterns and any changes. The bonus to it all is that “understanding more about these plants and their genetic variation will be pretty applicable to other species that have undergone the same processes,” she noted.

As scientists and volunteers worked in the field over the last several decades, they did more than collect genetic information. They also took steps to boost new seed production by hand pollinating plants or conducting a form of seed dispersal. Through her study, Ellwanger is also tracking the success of each technique. “I’ll be able to complete a genetic comparison over time to see if these recovery goals are achieving what they set out to do,” she said, by comparing the genetic composition of a given population from the recent past to today.

PHOTO: A compound light microscope reveals some plump, fertile embryos inside seeds — A compound light microscope reveals some plump, fertile embryos inside seeds.

At sites Ellwanger visited personally, she collected seeds as well, and brought them back to the lab for examination. There, looking under a compound light microscope, she checked to see what percentage of seed embryos from the sites were plump and therefore viable. Her findings offer an additional perspective on what her genetic analysis will show. After examination, the seeds were returned to their field location.

In early analysis results, “it looks like reproductive fitness does differ between sites so it will be really interesting to see if those sites that have lower reproductive fitness also have higher levels of inbreeding,” noted Ellwanger. Inbreeding, the mating of closely related individuals, can result in reduced biological fitness in the population of plants. In such cases, it could be helpful to bring in pollen or seed from other populations to minimize mating with close relatives and strengthen populations for future generations.

PHOTO: Eastern prairie fringed orchid (Platanthera leucophaea). — Eastern prairie fringed orchid (*Platanthera leucophaea*)

The eastern prairie fringed orchid will soon be better understood than ever before. The findings of the study may also provide insight into other problems that may be happening in the prairies where they live. “Orchids will be some of the first organisms to disappear once a habitat starts to be degraded. If we can better understand what’s going on with this plant it, could help out similar species,” said Ellwanger.

The researcher is looking forward to the impact this work could have on the future of the plant and the habitat that sustains it. “What motivates me about research is definitely the conservation implications,” said Ellwanger, who developed her love of conservation while growing up on the East Coast and learning about the complex systems that play a role in the health of the environment.

Read more about orchid research at the Garden, and don’t forget to visit the Orchid Show, open through March 13, 2016.