Archives For Plant Science & Conservation

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.

In the race to save native plants like purple New England aster and fragrant American mountain mint, the Chicago Botanic Garden freezes seeds for future use—but will frozen seeds be able to grow after hundreds of years in storage? Researchers are trying to find out.

Environmental threats such as climate change have caused thousands of plants to become rare or endangered. The tallgrass prairie, which has lost 96 percent of its land to agriculture and other human activities, is one of the earth’s most endangered habitats. By preserving seeds in the Garden’s Dixon National Tallgrass Prairie Seed Bank, researchers are working to ensure that native species don’t disappear in the wild.

Inside the seed vault at the Dixon National Tallgrass Prairie Seed Bank.

Inside the seed vault at the Dixon National Tallgrass Prairie Seed Bank.

In winter 2015–16, two students from the Garden’s graduate program, which is offered in collaboration with Northwestern University, helped with the Seed Bank’s first germination trials. In the trial, a sampling of our oldest seeds was removed from deep freeze—a vault at minus 4 degrees Fahrenheit—and placed in favorable growing conditions to see if they would germinate after 13 years of dormancy.

Alicia Foxx germination trials.

Graduate student Alicia Foxx hard at work counting…

Alicia Foxx germination trials.

…and removing seeds that have germinated on an agar medium.

The results? Species such as New England aster (Symphyotrichum novae-angliae), water speedwell (Veronica comosa), and American mountain mint (Pycnanthemum virginianum) germinated well. Species such as enchanter’s nightshade (Circaea lutetiana) and New Jersey tea (Ceanothus americanus) did not germinate; more research is needed to determine whether these seeds did not germinate because we were unable to figure out how to break their dormancy.

 

Graph showing results: Seed sample sizes for trial were either 24, 60, or 75 seeds, depending on the number of seeds in the collection.

Seed sample sizes for trial were either 24, 60, or 75 seeds, depending on the number of seeds in the collection.

The results show that seed collection is an efficient and cost-effective way to preserve biodiversity for future generations; experts predict that many of our native seed can survive hundreds of years in a seed bank (we’ll repeat the germination test in another ten years). Meanwhile, if you’re interested in joining our team and helping with the critical work of seed collection or banking, contact us

Download/read the full results here: Germinating Native Seeds from the Dixon National Tallgrass Prairie Seed Bank.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

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

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.

Garden researchers Fabiany Herrera, Patrick Herendeen, Greg Mueller, and Chen Ning

Garden researchers Fabiany Herrera, Patrick Herendeen, Greg Mueller, and Chen Ning in the field in 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.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

Most plants hate saltwater. Pour saltwater on your houseplants and, a little while later, you’ll have some wilty plants. But mangroves can grow—and thrive—in saltwater.

You may have seen mangroves if you’ve been to the Florida Everglades or gone to an island in the Caribbean. Mangroves are trees that live in tropical, coastal zones and have special adaptations for life in saltwater. One of these adaptations is in how they reproduce: mangroves don’t make seeds. Instead, they make living, buoyant embryos called propagules (prop-a-gyule).

Mangrove propagules come in different shapes and sizes. Each species has its own unique propagule.

Mangroves produce a huge number of propagules the same way an oak would make hundreds of acorns.

Mangroves produce a huge number of propagules the same way an oak would make hundreds of acorns.

These relatively small propagules could become giant red mangrove trees.

These relatively small propagules could become giant red mangrove trees.

Black mangrove propagules on a branch; their outer coating will dissolve on their journey downstream.

Black mangrove propagules on a branch; their outer coating will dissolve on their journey downstream.

Propagules come in different shapes and sizes. These are from a tea mangrove (Pelliciera rhizophorae) tree.

Propagules come in different shapes and sizes. These are from a tea mangrove (Pelliciera rhizophorae) tree.

Normally, trees reproduce with seeds. You’ve probably seen the whirlybirds of maples and acorns of oaks. These seeds can go dormant. They are basically “asleep” or hibernate until something—water, temperature, or physical damage—wakes them up, allowing them to start growing months or years after they are produced.

Here I am with a couple of mangrove specimens. These roots are in water at high tide, but exposed at low tide.

Here I am with a couple of mangrove specimens. These roots are in water at high tide, but exposed at low tide.

Propagules, on the other hand, don’t have that luxury—they fall off their parent tree, ready to start rooting and growing a new tree. Nature has provided an amazing way for the mangrove seeds to move away from the parent tree: they float.

As the propagules float through the water, they shed their outermost layer and immediately start growing roots. The clock starts ticking as soon the propagules fall—if they don’t find a suitable place to start growing within a certain amount of time, they die. If a mangrove propagule ends its journey at a location that’s suitable for growth, the already-rooting propagule will send up its first set of leaves—cotyledons.

Ocean currents can take propagules thousands of miles away from where they started. A mangrove’s parent tree might be around the corner or around the continent.


Dr. Emily DangremondDr. Emily Dangremond is a postdoctoral researcher at the Smithsonian Environmental Research Center and a visiting scientist at the Chicago Botanic Garden. She is currently studying the ecological and evolutionary consequences of mangroves responding to climate change at their northernmost limit in Florida.


Students in the Chicago Botanic Garden and Northwestern University Program in Plant Biology and Conservation were given a challenge: Write a short, clear explanation of a scientific concept that can be easily understood by non-scientists. This post is part of their series.

©2016 Chicago Botanic Garden and my.chicagobotanic.org

When buckthorn moves in to the ecosystem, it dominates.

Imagine a friend invites you to a dinner party, promising a delicious spread of food and libations. You arrive, excited and hungry, only to find nothing but raw kale, brought by an uninvited guest. Regardless of your feelings about kale, this would be pretty underwhelming. The other guests are obviously disappointed about the monotonous spread. Most people leave, and because most people aren’t eating the kale, the kale continues to dominate the party. Even if someone brought in better foods that more people enjoy, there is no room on the tables. The kale is everywhere!

PHOTO: Buckthorn (Rhamnus cathartica).

Common buckthorn (Rhamnus cathartica)

While not a perfect analogy, this anecdote relays the reasons why buckthorn invasion is detrimental to forest ecosystems. The dinner guests are like the other plants and animals that usually live in the woods. They have certain dietary needs, and if those needs cannot be met, they will have to leave and find another place to live. The more one species dominates (kale, or in many local forests, buckthorn) the fewer species can live there, leading to the ecological equivalent of a party that ends at 8:30, just as everyone was arriving. While it may be true that one person at the party really likes kale, it’s hardly fair for the preferences of that person to supersede everyone else’s needs. In the case of buckthorn, many have opposed its removal because that denies robins a berry that they enjoy. However, keeping the buckthorn (which doesn’t belong there in the first place) is like keeping all of the kale on the tables and not allowing for other foods to be served just for that one person. Even more frustrating, the person that likes kale has plenty of other dietary options. Kale isn’t even their favorite food!

PHOTO: The McDonald woods shows healthy filtered sunlight and native plant understory growth after buckthorn removal.

The McDonald woods shows healthy filtered sunlight and native plant understory growth after buckthorn removal.

To many people, the idea of cutting down trees to help forests grow stronger is counterintuitive. But buckthorn is no ordinary tree. It is an invasive species, meaning that it doesn’t belong in Chicago area forests, and it steals resources from the plants that are supposed to live here. So remember, when you hear people talking about cutting down buckthorn, they are actually doing it to make the habitat healthier and more inclusive in the long term. They are working to replace the kale at the party with better food and drinks, ensuring that all the guests that were invited can have a good time, staying up until sunrise.

Read more about our ongoing buckthorn battle, and see the difference removal makes in restoring an ecosystem.


Bob Sherman

Bob Sherman is an undergraduate studying environmental science at Northwestern University. His research interests include prairie restoration and how abiotic factors impact prairie and forest ecosystems. He hopes that his research will have a positive impact on ecosystem restoration and management.


Students in the Chicago Botanic Garden and Northwestern University Program in Plant Biology and Conservation were given a challenge: Write a short, clear explanation of a scientific concept that can be easily understood by non-scientists. This post is part of their series.

©2016 Chicago Botanic Garden and my.chicagobotanic.org

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.

The Dixon Prairie in July

The Dixon Prairie in July

“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.


©2016 Chicago Botanic Garden and my.chicagobotanic.org