Archives For seed banking

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

Wildfire. Flooding. Thirst. These issues can all be addressed through large-scale landscape restoration, according to speakers at the 2015 Janet Meakin Poor Research Symposium. Addressing a crowd of regional stewardship professionals and academics, as well as Conservation Land Management (CLM) and Research Experiences for Undergraduate (REU) interns at the Chicago Botanic Garden on June 12, they focused on solutions for ecological challenges.

The effects of strong conservation work are magnified when done on a large scale, they shared, and the theme of the day was how to magnify every step from seed-management procedures to restoration time frames and budgets to make the process as beneficial as possible. As mining, drilling, and similar industries move broadly across open lands in the United States and abroad, along with increasingly frequent and far-reaching extreme weather events, conservation practices must evolve with the times to keep pace.

PHOTO: Conservation and Land Management (CLM) interns measure species density in the field.

Conservation and Land Management (CLM) interns measure species density in the field.

As the CLM interns prepare to set off on a summer of hands-on restoration work across the United States, and potentially launch their careers shortly thereafter, these are critical issues for them to understand, according to Kay Havens, Ph.D., of the Chicago Botanic Garden, who organized the symposium. Many of the interns work in partnership with the Bureau of Land Management (BLM) on the ground in forestry, wildlife management, and habitat restoration, among others.

Fittingly, the first speaker of the day was Amy Leuders, the acting assistant director of BLM, who noted that the partnership with the Garden since 2001 has led to the training, hiring, and placement of more than 1,000 interns on federal lands. About 50 percent of those interns are later hired by a stewardship agency. “The Bureau of Land Management has had a long and successful partnership with the Chicago Botanic Garden…developing the next generation of land stewards,” she said.

In particular, she imparted to the audience the importance of developing a large scale national seed strategy, so that targeted plant seeds will be thoughtfully collected and preserved for future use. She cited examples of events in which seeds saved by chance allowed for the restoration of areas that later succumbed to natural disasters like wildfires and hurricanes. This new process would allow for seed saving to take place in a more proactive and calculated manner.

PHOTO: Seeds are collected at the Garden and stored in the Dixon National Tallgrass Prairie Seed Bank.

Collected seeds are stored in the Dixon National Tallgrass Prairie Seed Bank.

According to the second speaker, Kingsley Dixon, Ph.D., professor at Curtin University and the University of Western Australia, the current supply of wild seed cannot support global restoration demands. Innovations are helping to change that. Tools that process seeds into pellets or other small packets facilitate their successful mass delivery into recovering ecosystems, helping to achieve the level of seed performance seen in the agricultural sector. He noted that “Only by thinking at an industrial level of efficiency will ecological restoration be able to achieve the pace needed to protect and enhance natural resources.”

Drinking water quality can also be managed by restoration, said Joy Zedler of the University of Wisconsin-Madison. She shared examples of how restoration has been “scaled up” adaptively (learning while restoring) to benefit large areas. When it comes to managing water, she explained, it is essential to manage an entire watershed. One area of poor water quality will flow into every crevice in the system, for example. In the end, she explained, it is about safeguarding ecosystem services that human health and wellbeing depend on, from clean water to fresh air. “Our global society needs to redirect itself to achieve a sustainable future,” she said.

Brian Winter of the Nature Conservancy in Minnesota echoed her sentiments, as he ran through a real-life wetland restoration process for the audience. He emphasized that wetlands hold rainwater and are capable of preventing disastrous amounts of water from washing through nearby agricultural fields. The value of wetland restoration is immense and ongoing, he explained.

Conservation is in transition, explained speaker John Rogner of the U.S. Fish and Wildlife Service. Rogner discussed the steps involved in planning for a successful restoration, and the importance of landscape conservation cooperatives that can work together across states or even countries to identify and address issues in a given geographic area such as the Great Lakes watershed. He outlined an ongoing project to improve blockages in the Great Lakes system that impede fish migration. This can lead to a buildup of invasive plant species that create additional system blockages. A regional perspective and collaboration across entities is critical, he said. “It is absolutely essential that everyone have access to the same information to keep moving in the right direction,” added Rogner.

Issues that often fall to the side in planning are conceptual, according to James Aronson of the Missouri Botanical Garden. He urged the audience to pay attention to the economic side of their work by learning to speak and think in terms of renewable natural capital. Across land and ocean, natural capital can be restored to facilitate the flow of ecosystem services such as fresh air and clean water.

PHOTO: One of our greatest national resources and treasures: the Colorado River Basin.

One of our greatest national resources and treasures: the Colorado River Basin.

Lastly, Megan Haidet with Seeds of Success emphasized the importance of partnerships to meet the goals of the Bureau of Land Management’s National Seed Strategy for Rehabilitation and Restoration 2015–2020. She noted that increased coordination is vital to accelerate the pace and scale of restoration and provide native plant materials when and where they are needed.

The Garden’s CLM interns have now dispersed across the United States, where they will work for the next five months on public lands to put these lessons into action.


©2015 Chicago Botanic Garden and my.chicagobotanic.org

In late October 2012 when I was driving down a country road in rural northwest Illinois, I spotted some bright sky-blue asters blooming near the corner of a woodlot. I was traveling between nature preserves in this area of the state collecting seeds for the Dixon National Tallgrass Prairie Seed Bank, so my mind was already tuned in for interesting native flora that might produce a collection for the seed bank. It was impossible to make a positive I.D. traveling at 60 m.p.h., but the color of that patch of blue was intriguing enough to warrant turning around to go back for a closer look.

As I had hoped, the attractive blue flowers belonged to a fine native species called Short’s aster (Symphiotrichum shortii), which inhabits high quality woodlands. This being the case, I thought it prudent to take a peek into the adjoining woodland to see what else might be growing there. To my surprise, within 30 feet of my entry point I stumbled across a large patch of goldenseal (Hydrastis canadensis)—a once common but now rare plant of Illinois woodlands. Its rarity is attributed to its past popularity as a medicinal plant, which led to its overharvest. Along with goldenseal, other quality woodland plants such as bellwort (Uvularia grandiflora) and baneberry (Actaea sp.) were also present.

PHOTO: golden seal (Hydrastis canadensis) in bloom.

This native woodland perennial produces two large, broad, palmately divided leaves atop a 1-foot-tall hairy stem. A small cluster of greenish-white flowers are produced at the base of one of the leaves in spring when the leaves are expanding, and they mature into a cluster of bright red fruits by midsummer. The knotty, bright yellow root of goldenseal has been harvested by humans for centuries for a variety of medicinal uses. Its popularity has led to extreme harvesting pressure culminating in drastically reduced natural populations.

I did not have time to explore the woodland further that day, so I made a note of where it was located and planned on returning to the site soon to explore it further. However, I had one question that I needed to answer before this was to happen: Who owned that woodland? I was confident that it wasn’t a nature preserve, because I had lists and maps of all of the protected preserves in the area. My guess was that it was privately owned. When I left the site, I recalled that there was a home situated just off the road near the middle of the woodland, so I thought that would be a good starting point.

PHOTO: Hydrastis canadensis leaves (with one ripe fruit).

Hydrastis canadensis leaves (with one ripe fruit)

As luck would have it, the owners of the home also owned the entire woodland. I spoke to the owner about the goldenseal I found in the corner of his property and the possibility of making a collection for the seed bank. It turns out that he already knew about the goldenseal population from a conversation that he had had with a local forester years ago. The forester thought that there was a good chance it had been planted there to be harvested for its medicinal value at a later date. This was a likely scenario, considering the size of the population. The owners agreed to allow me to collect its seeds as well as seeds from any other species that I sought for the seed bank. The only problem was that for the seed bank we are primarily interested in preserving the seeds of natural populations, not introduced ones. Seeds from natural populations represent individuals that are ideally suited to that environment by natural selection across generations, and are therefore of more value to those seeking genetically adapted seeds from a particular area.

PHOTO: Hydrastis canadensis fruit.

The raspberry-like fruit of goldenseal is considered inedible, but the roots have many medicinal properties.

So here lies the dilemma: large populations of goldenseal are rare, because of overharvesting. I rarely see this plant in woodlands, and when I do, it is always in small numbers. If this population was cultivated for the medicinal value of its roots, there is a good chance that it does not represent a natural population. I did not collect seeds of goldenseal that fall—the seeds had ripened and dropped much earlier in the summer. Any seed collection for the seed bank could not occur until the following year. This gave me plenty of time to contemplate whether or not to make the collection.

Since my first visit to the woodland, I have made several seed collections of many quality native woodland plants for the seed bank, including a collection of the Short’s aster that led me to the goldenseal discovery. During those collections I have become more familiar with the woods and have discovered additional colonies of goldenseal—some quite distant from the original population. Could these additional colonies represent multiple plantings? Maybe, but the sizes of the additional colonies are quite a bit smaller than the original. Perhaps they represent offspring from the original colony. If that is the case, this may be an indication that this particular woodland is an ideal habitat for goldenseal—even if it is not the original habitat. Or, there is a chance that this is a remnant population that for some reason survived overharvesting forays years ago.

PHOTO: A field of goldenseal in fruit.

A population of goldenseal on the property; one of several colonies where seeds were harvested

I completed a collection of the goldenseal population (estimated at more than 500 plants) for the seed bank on July 24, 2013. A notation in our database notes will read: “Population may not be natural.”


©2013 Chicago Botanic Garden and my.chicagobotanic.org