By Jeff Cologna and Joy McKinney
Each steward at Nachusa Grasslands has a fascinating personal tale, often involving stories of sacrifice, setbacks, and success. Together, with the resources of The Nature Conservancy, volunteers, donors, and Illinois Clean Energy Community Foundation, stewards work hard to ensure Illinois prairie is not merely a fading memory, but a lasting reality for all future generations. Mike Carr, one of these amazing stewards, shared a few stories from the past with us. The following paragraphs highlight those early days.
Mike’s story began as a boy whose father loved the great outdoors but "bemoaned endlessly about all the invasive plants.” His father, Francis Carr, taught him about invasive plants and how to identify trees by their bark, enabling him to identify them all year ‘round. Little did he know back then that these skills and a disdain for invasives would serve him so well at Nachusa.
In the Spring of 2010, soon after “getting away” from the city of Chicago, Mike found himself “banging on the door” of Bill Kleiman, Nachusa’s Director. Early in their discussions, Bill explained how critical fire is to restoring and maintaining healthy prairie landscapes. Experience managing fire became a top priority. Mike quickly completed a 40-hour online fire certification class leading to an absolute “love of fire” as well as the acquisition of key skills for participating in controlled burns.
Mike was then challenged by Bill Kleiman and Cody Considine, restoration ecologist at Nachusa, to take on a unit of his very own which would later be named Big Jump. We asked Mike why the 350-acre unit was given this interesting moniker. Apparently, it was the result of a naming contest among stewards. His unit is basically “a long way from the HQ.” Due to the number of high-quality remnants within its boundaries, Mike’s restoration activities have opened up the landscape, enabling unseen natives such as porcupine grass, arrow leaf violets, and blue-eyed grass to show themselves, surprising and delighting Mike. Every year he discovers new “surprises” that weren’t there before. “The whole hillside of one remnant is filled with violets in the spring and another remnant with Carolina rose, bird’s foot violet, comandra, and pussy toes.
Mike focused his efforts on a 23-acre plot within the unit which is now known as “Orland Prairie." In the beginning of restoration, Mike shared that Orland Prairie needed some kind of push to get rid of all the invasive woodies (shrubs and bushes) so the prairie could find its way. In the last 10 years, Nachusa’s Fecon mower was used to knock down the invasive woodies. Seed, collected by combine, was then spread on the area, beginning the restoration process. Unfortunately, woodies continue to dominate.
Restoration efforts continue at Orland Prairie with the help of a generous grant from the Illinois Clean Energy Community Foundation. The grant is being used in part to purchase herbicide for continued eradication of the highly invasive autumn olive plant and other woodies. The application of the basal bark herbicide is highly effective. “If you stand next to an autumn olive and you tell it that you’ll come back with basal bark . . . it’ll just die!” Mike quipped. Basal bark applications have been used to successfully eradicate infestations of autumn olives, which at one time stood up to 15 ft high and covered the entire 23 acres. Mike shared that the herbicide is most effective after a fire.
Mike Carr is just one of the many dedicated men and women who have committed to making Nachusa Grasslands more than just a memory. We would like to thank Mike’s dad for inspiring him to be patient and dedicated to long term goals and above all, valuing and respecting nature.
Come meet Mike on the March 2nd workday to see the Orland Prairie and experience the whimsical beauty of Nachusa Grasslands!
By Kaleb Baker
Amur honeysuckle (Lonicera maackii) is an invasive shrub that flourishes along forest edges and in open woodlands such as those at Nachusa Grasslands. Amur honeysuckle shades out native flora with its early leaf-out and prolonged leaf retention, and when left uncontrolled, can produce a near monoculture, threatening biodiversity.
Land stewards everywhere have implemented a variety of different eradication methods, including hand pulling, cut-and-treat with herbicide, foliar-applied herbicide from backpacks or helicopters, basal bark herbicide treatments, and prescribed fire. Continuous treatments and monitoring are needed to eradicate Amur honeysuckle, making the cost, effort, and time requirements of controls important.
Knowing the efforts we go through to manage honeysuckle, as well as the amount of conjecture surrounding the best practices, I worked with my advisor Dr. Nick Barber to study how effective basal bark treatments and prescribed fire are at controlling honeysuckle., I decided to study how effective basal bark treatments and prescribed fire are at controlling honeysuckle. Basal bark and fire are regularly-used control methods at Nachusa. Basal bark treatments involved spraying a 20% solution of triclopyr herbicide around each plant’s base from a backpack, which was both quick and easy. In this study I included 800 individually-marked Amur honeysuckle at 5 different sites within Nachusa Grasslands and Franklin Creek State Natural Area. Basal bark treatments were applied in fall 2017, winter 2018, early spring 2018, and late spring 2018 to see if the season of application affected the mortality of honeysuckle or the extent of damage to non-target flora. Prescribed fire was administered to half of each of the 5 sites in spring 2018. I then checked mortality in the early fall of 2018 to allow the honeysuckle time to either drop its leaves and regrow them (falsely dead) or to retain its leaves for an extended period of time before dying (falsely alive).
I found that basal bark applications were equally effective at killing Amur honeysuckle, regardless of treatment timing. The combined mortality rate of herbicide treatments was 98.4% across all herbicide treatment seasons, compared to a 2.5% mortality with no basal bark treatment. Prescribed fire did not impact mortality positively or negatively.
I also placed a 1m2 quadrat around 200 Amur honeysuckle to measure off-target damage to the plant community in spring 2018, finding a decrease of living cover equating to about a 10-inch radius. The off-target “ring of death” did not differ based on fire treatment or basal bark season.
I was lucky to receive a grant from the Friends of Nachusa Grasslands where I will be able to return in May 2019 to resample the off-target vegetation quadrats to evaluate how quickly the flora recover from the various treatments.
From my current results, I highly recommend using basal bark treatments to control Amur honeysuckle for all but the highest quality of areas. The speed and ease of use allow managers to cover large swaths of invaded areas across fall, winter, and spring seasons. The standing dead material from the honeysuckle can be reduced with a masticator or brush mower in the non-growing season or with regular prescribed fire, which should be implemented anyway.
Kaleb Baker is a Master's Candidate at Northern Illinois University, focused on natural areas management practices, and current Stewardship Committee Chair for Franklin Creek Conservation Association.
By Dee Hudson
What does a degraded landscape look like?
Take a good look at the image below. The two volunteer stewards can barely walk through this dense thicket of invasive bushes. The sheer number of invasives that reside here have crowded out most other species, and as a result, have limited the possible diversity. In addition, when leafed out during the summer time, the bushes block the sunlight from reaching the ground and therefore discourage native species from growth.
As Orland Prairie’s land steward, Mike Carr led the December 8 Saturday workday into this gnarly section in the attempt to eradicate the invasive brush. At the end of the day, each volunteer stewardship hour was carefully logged, because Illinois Clean Energy Community Foundation has approved this particular habitat as a grant project. When 400 volunteer hours of habitat care have been recorded, Illinois Clean Energy will present $4,000 to Friends of Nachusa Grasslands.
What species are targeted for removal?
How is the brush eradicated?
On this workday the volunteers treated the brush with basal bark applications. The treatment was applied to the base of the bush with either a backpack sprayer or a hand sprayer.
What does a restored landscape look like?
This landscape is also a part of the 23-acre grant project. The area once looked very degraded, but with basal bark treatments and prescribed fire, the brush understory was removed. Then prairie seeds were planted and the photo above shows the successful restored results. This area has been given new life and is on its way to recovery.
Who restores these habitats?
Anyone who wants to make a difference can help with restoration!
Next ICE Grant Workday
Join fellow volunteers on December 22, 2018 for the next ICE Grant Saturday workday. Meet at Nachusa’s Headquarters Barn before 9 am and be ready to restore habitat. If you have any questions about the workdays, check the Friends of Nachusa Grasslands website.
Let’s make a difference together!
By Dr. Elizabeth Bach, Ecosystem Restoration Scientist
December 5 is World Soil Day, a time to recognize the vital role soils play in our ecosystems and health: growing food, filtering water, recycling air, mitigating climate change, and supporting more than 25% of all biodiversity! Soil is the foundation of prairie restoration at Nachusa Grasslands, the starting point of a prairie planting. There are many questions about how soils impact prairie restoration success and how prairie restoration affects soils. Today, we highlight a few of the soil-focused scientific studies that have been conducted at Nachusa Grasslands:
Question: Do communities of soil critters like earthworms, ants, ground beetles, centipedes, millipedes, and spiders change during prairie restoration?
Prairie restoration increases the number, abundance, and mass of soil critters like earthworms, ants, centipedes, and spiders with time since planting. Interestingly, different prairie remnants, even within the Nachusa preserve, have very different communities of soil invertebrates, and it’s difficult to know what a typical remnant invertebrate community may look like.
Wodika & Baer 2015. If we build it, will they colonize? A test of the field of dreams paradigm with soil macroinvertebrate communities. Applied Soil Ecology 91:80-89
Wodika et al. 2014. Colonization and recovery of invertebrate ecosystem engineers during prairie restoration. Restoration Ecology 22: 456-464
Ground beetles show a different pattern, with high numbers of species and abundance in young plantings. Although older plantings had lower species richness, the roles those species play in the ecosystem diverged, indicating that older plantings support stable, diverse beetle communities that fill multiple roles in the ecosystem (e.g. different sizes, active at different parts of the day/night, eating different things).
Barber et al. 2017. Species and functional trait re-assembly of ground beetle communities in restored grasslands. Biodiversity and Conservation 26:3481-3498
Question: Do soil microbial communities change during prairie restoration?
Older restorations at Nachusa host microbial communities that are distinct from younger plantings, and that more closely resemble remnant communities. A couple of the key bacterial groups distinctive of prairie remnants and older restorations are Verrucomicrobia and Acidobacteria. The next question is to learn more about what those bacteria do!
Barber et al. 2017. Soil microbial community composition in tallgrass prairie restorations converge with remnants across a 27-year chronosequence. Environmental Microbiology 19: 3118-3131
Question: How does plant diversity impact ecosystem functions like soil carbon and nitrogen cycling?
Nachusa’s high plant diversity restorations had more roots, more microbial mass (especially mycorrhizal fungi), more structured soil, and less “leaky” nitrogen compounds that can wind up in water ways compared with low plant diversity restorations in the same area. This is the first study to show that very high plant diversity restoration can lead to improved ecosystem functioning.
Klopf et al. 2017. Restoration and management for plant diversity enhances the rate of belowground ecosystem recovery. Ecological Applications 27:355-362
By Leah Kleiman
Summer is a busy time of year on the prairie with invasive weeds sprouting up and native plants going to seed. That's why every year Nachusa hires half a dozen seasonal staff to keep up with the workload from May through November. Typically the hired staff are in their twenties and going into careers in ecological restoration/conservation.
During May, June, and July we will spend the majority of our time spraying and spading invasive weeds in the hot sun to keep them from taking over the prairie plantings. Backpack sprayers are used to apply herbicide to weeds such as sweet clover and bird's foot trefoil until they start going to seed. Then we will pull them by hand. By mid-August weed season is over and it's time to focus on seed collection.
As each native plant species ripens, the crew will go out and collect them by hand in buckets and barrels. We may collect anywhere between a few ounces to several hundred pounds, depending on the species size and density. After the seed is collected it will be dried on racks in our seed barn and then milled to separate the seed from the chaff. In the late fall the crew will spread the seed we collected in brand new plantings that have not seen prairie in recent years. This year we will plant several areas with a range of habitats. For the most part the seed mixes will be spread using seeders pulled behind trucks and utility terrain vehicles. The crew of 2018 has already covered a lot of ground in weed sweeps and collected some precious prairie plants. Stay tuned for another crew report in the fall!
Meet this year's hardworkers
Nathaniel Weickert is the crew leader, and this is his second summer working at Nachusa. He is from Rockford and received his Bachelors in Biological Sciences from NIU in 2015. He hopes to acquire a Masters degree and continue working in the field of restoration and conservation. In his free time Nathaniel enjoys reading, hanging out with his friends and family, and producing art.
Avery Parmiter is from Connecticut and earned her B.S. in Environmental and Natural Resource Management from Clemson University in 2015. Avery would like to continue to be based in the field of conservation and looks forward to furthering her knowledge about restoration ecology in her second year at Nachusa. In her free time she enjoys traveling and exploring natural areas.
Kim Elsenbroek is from Kingston, Illinois and earned her B.S. in Plant Biology from Southern Illinois University at Carbondale in 2012 and her M.S. in Evolution, Ecology and Behavioral Biology in 2015 from Indiana University at Bloomington in 2015. She was also on the crew in the fall of 2015. Kim aspires to continue working in the field of restoration and conservation as a practitioner, researcher, and/or teacher. In her free time Kim is a dancer and dance teacher/choreographer at Dance Dimensions in DeKalb.
Tyler Berndt is from Minooka Illinois. He recently graduated from Southern Illinois University at Carbondale with a BS in Zoology Wildlife Biology and is currently seeking graduate level opportunities. Tyler had previously worked at Nachusa as an undergraduate ornate box turtle technician. He values learning more about the political and interpersonal deliberations needed to connect fragmented habitats and human dominated ecosystems. Tyler would like to be a consultant or coordinator for organizations like The Nature Conservancy and the USDA Forest Service. In his free time he enjoys exploring state and national parks, historical sites, and cities.
Karey O'Brien is from Minooka Illinois and graduated with a B.S. in Environmental Science from Lewis University. She recently worked at the Forest Preserve District of Will County as a Natural Resource Management Seasonal Laborer. Karey hopes to improve her plant identification skills and continue learning more about natural areas management while here at Nachusa. In her free time Karey enjoys hiking, biking, and watching movies.
Leah Kleiman is a volunteer. This is her second summer working with the crew. She grew up on Nachusa and is working on her A.S. in biology at Sauk Valley Community College. Next year Leah will be transferring to Southern Illinois University at Carbondale to earn her B.S. in Plant Biology and Ecology. She plans to pursue a career in restoration/conservation. In her free time Leah enjoys sketching, hiking, swimming, and hanging out with her friends.
Bios written by the individuals.
Filling our backpack sprayers with herbicide before heading into the field.
Once in the field, we line up and walk transects across each prairie planting searching for invasive weeds to spray.
Picking violet wood sorrel (Oxalis violacea) on a remnant knob. This little prairie flower produces a seed close to the ground so spotting it can be difficult.
By Ryan Blackburn
In the spring of 2013, I had little to no knowledge of tallgrass prairies or the various forms of life they held. I was an undergraduate at the time, and my class at Northern Illinois University had an opportunity to visit Nachusa Grasslands and receive a tour given by one of their dedicated stewards, Jay Stacy. As the class looked out across the beauty rolling over the tallgrass landscape, Jay directed our view downwards at our feet and started naming twenty or more plant species in just a little patch of dirt the size of a laptop. Jay also spoke of the rumors that bison may be coming to the landscape and how they were thought to have the ability to increase diversity of the prairie plant communities which already seemed teeming with life. This was the moment I realized that the tallgrass prairie and plant communities they held were something that I wanted to know more about. After a couple of growing seasons, a reintroduction of bison onto the landscape was accomplished, and my masters research was born.
Bison are large animals that require a lot of energy, which mainly comes from one family of plants, the grasses (Poaceae). Due to this selective grazing, bison create open space in their habitats for wildflowers to take root and increase the diversity of the tallgrass prairie overall. At least this is a summary of what had been observed in the research of remnant (never-plowed) prairies west of the Mississippi River which reintroduced bison as well. In hopes to recreate this tale of romance between bison and tallgrass prairies, Nachusa Grasslands reintroduced bison to their preserve of both remnant and restored lands. The question still remained: will their diet in this new area largely be made up of grasses, and how soon would we see changes in the plant communities following their reintroduction? To study this, I looked at both bison diet and differences of plant communities between sites with and without bison over a period of two years.
To figure out what the bison were eating, I used a technique called stable isotope analysis on bison tail hair pulled during the annual roundup. This allowed me to find signatures of plants within the bison hair and estimate these plants' abundance within bison diet. Better yet, I could cut bison hair into segments and look for seasonal changes. Through this analysis I was able to estimate major dietary groups of their diet between May 2016 and September 2016. I found that bison were doing what Nachusa brought them here to do: eat grasses (for the most part)! However, in late summer bison started to transition from largely grass species to wetland species and some wildflowers, something that had never been documented before. This was an unexpected shift that may lead to unforeseen consequences to wetlands, but further research is needed to speak to this.
Now that we know bison are mostly eating grasses during the growing season, we want to know how this might be impacting prairie plant communities. Attempting to answer this question, I, along with a team of dedicated plant enthusiasts, counted and measured percent cover of plant species across sites with and without bison. I quantified these communities in a variety of ways and compared them to see if bison were driving any differences between the two communities. Even though the bison had only been at Nachusa for three years, there were already evident changes happening within the plant communities. As predicted, areas with bison had more variation within their plant communities and had a higher ratio of native to non-native plants than those sites without bison. Further analysis shows that both variation and native to non-native ratios may be driven by bison preference of certain species such as bluegrasses (Poa compressa and Poa pretensis) suggested by a higher occurrence of these species in sites without bison.
The bison of Nachusa Grasslands were reintroduced to do a job: increase the diversity of plant communities. Though my research does not yet see an increase in diversity, it does suggest that bison are starting to go to work eating grasses and changing plant communities around them. Continued monitoring of these communities (especially those tasty wetland communities) is needed to gain a better understanding of bison impacts and how they progress in restored tallgrass prairies.
Ryan Blackburn just received his M.S. degree studying bison diet and their role in the restoration of plant communities in tallgrass prairies. Ryan is also looking at grazing impacts on a landscape scale using drone aerial imagery. In 2016, he received a $1,500 Friends of Nachusa Grasslands Scientific Research Grant for his "Determining Bison Diet and Bison Effects on Vegetation in a Chronosequence of Restored Prairie at Nachusa" project.
By Mary Meier
What do 400 hours of volunteer stewardship, $7,000 in donations, and 100 hours of social media posts have in common? They are all components of the Illinois Clean Energy Community Foundation’s Community Stewardship Challenge Grant Program.
The Foundation encourages increased local support and participation in the care of habitat by providing grant funds as a match to local dollars raised and labor donated.
Friends of Nachusa Grasslands has been approved for grants totaling $32,000 if we fulfill requirements under several categories:
Friends chose Nachusa’s Orland Prairie, a prairie remnant on the west end of the Big Jump Unit, for its habitat restoration project site. Volunteers have already begun attacking the 23-acre parcel that is heavily infested with the invasive shrub autumn olive. Non-native honeysuckle is also rampant in the area.
Mike Carr, Orland Prairie volunteer steward, who has been working on the unit for several years, says,
“I really enjoy brush clearing, especially the nasty stuff.”
Both autumn olive and honeysuckle are some of the most tenacious foes that Nachusa’s volunteers battle.
According to The Nature Conservancy, “Autumn olive is quickly becoming one of the most troublesome shrubs in central and eastern United States. High seed production, high germination rates and the sheer hardiness of the plant allow it to grow rapidly.”
In addition, a University of Illinois extension website says, “Controlling bush honeysuckle is vital to the preservation of native ecosystems in Illinois. Bush honeysuckle currently poses one of the greatest threats to forest ecosystems in Illinois.”
Saturday workday crews and individual volunteers are using herbicides to kill the woody brush invading Orland. Later this year and early next year, we will over-seed the area with native species collected during the harvest season, conduct prescribed burns, re-contour unsightly gravel pits, and remove non-native trees and large debris from fence rows at the site.
Our long-term goal is to establish a diverse prairie planting on the 23-acre site, providing for long-term weed management and suppression of non-native shrubs and trees. Ongoing stewardship efforts, including volunteer labor, herbicide application, and controlled burns, will gradually help integrate the target area into the surrounding habitat.
How can you help Friends earn the stewardship grant? Volunteer for a Saturday brush clearing workday at Orland Prairie — the next one is on June 9. During the summer and fall, you can also help collect prairie seeds for Orland from the preserve. The Friends Social Media Team uses Facebook, Twitter, Instagram, and our website to promote volunteer opportunities.
You can also follow Illinois Clean Energy Community Foundation’s Community Stewardship Challenge Grant Program on Facebook and Twitter to learn more about the Foundation.
By Heather Herakovich, MS
Birds are known harbingers of spring. Although most stick around during the brutally cold Illinois winter, we don’t take much notice until they are everywhere in our yard, waking us up in the morning and pooping on our cars: spring time!
It’s finally springtime, and at Nachusa the birds are singing, vying for territory, and finding mates. These aren’t your typical backyard birds like the American robin and northern cardinal, who are your usual early morning alarm and repeating snooze. Nachusa holds a wide variety of bird species, including some of the ones in the most need of conservation: grassland birds. They come with funny names like bobolink and dickcissel, and in all shades of brown and yellow and sometimes black.
Grassland (prairie) birds are declining at a faster rate than most bird species, and a majority of this has been caused by habitat loss. Illinois is the prairie state, but only one hundredth of its original prairie remains. Places like Nachusa are doing their best to restore the agriculture fields and recreate the best prairie as humanly possible. Doing this requires a lot of hard work, hours of picking seed, planting seed, removing unwanted plants, burning portions of the prairie and mowing. The birds seem to be responding to this management fairly well. However, there is an elephant in the room, or shall I say a bison in the prairie.
American bison are our national mammal, and rightfully so. These large herbivores used to roam most of the contiguous United States, until they were hunted to near extinction. I’m sure you’ve heard the story. But now they’re back! Grazing is a crucial disturbance in prairie habitat, providing habitat for a lot of species and open space for a lot of plants. But how will birds respond to this large, iconic grazer on its new home in Franklin Grove, Illinois? When I started my graduate degree at Northern Illinois University in 2013, I was able to start trying to answer that question more specifically by looking at how their nests were going to be impacted by bison.
Bison can impact bird nests in a variety of ways. There are the obvious negative direct ones like trampling and dislodgement, but there are also some not-so-obvious impacts. These impacts can be either positive or negative and can affect the nesting habitat, nesting material, clutch size, and ultimately the survival of the chicks until they leave the nest (nest success). Seeing if bison are impacting nest success means I must find the nests first. This is the most difficult part. They are roughly the size of a compact disc, made from the vegetation they are in, and wickedly hard to find. If you come by Nachusa early in the morning this summer, I’m sure you’ll see me walking in the prairie, waving around a stick, and waiting “patiently” for a bird to fly from the vegetation.
Although difficult, watching these nests through time is a very rewarding experience. I’ve seen nests being built, eggs being laid, chicks hatching, and chicks leaving the nest. Please don’t try this at home, though. Nests are sensitive to human disturbance, and I follow specific protocol to not influence their nest success. Bison don’t seem to be influencing their nest success either, negatively or positively. This is good news. They are one of the main sources of disturbance in the prairie, and it is a relief that they are not trampling nests of birds in decline, at least four years post-reintroduction. Watching these nests is only a part of my graduate research. I am also looking at how bison may influence nest predators, brood parasitism by brown-headed cowbirds, and what bird species are present. So far, I am not seeing anything change enough to be consider a bison impact. Time will tell if there will ever be a noticeable impact of bison on grassland birds. If I were here in ten years, I would try to find out.
The beautiful prairie and bison are a great reason to visit Nachusa, but don’t forget about the birds. Sure, they all look similar and are hard to spot, but they are our harbingers of spring and make the prairie sing in the summer.
Heather Herakovich is a PhD graduate student at Northern Illinois University. Heather studies grassland bird nest density, nest success, and species composition in restored plots of varying age as well as remnant control prairies. Heather is attempting to quantify the effects of bison reintroduction, prescribed fire, and restoration age on grassland bird populations at Nachusa.
By Chris Helzer
Because they can’t run away, plants may seem helpless against the many large and small herbivores that like to eat them. Nothing could be further from the truth.
Many plants have physical defenses such as thorns or stiff hairs to deter animals from eating them. Grasses contain varying levels of silica, which can increase the abrasiveness of their leaves and help make them more difficult to eat and digest. In addition, the chemical makeup of many plants helps make them unpalatable or toxic to potential herbivores. While herbivory is certainly a major threat, plants also have a variety of defenses against pathogens (diseases). If you’re interested in more background on this topic, here is a really nice overview of plant defenses against both diseases and herbivores.
Within the last few years, there have been a couple of published studies that highlight some fantastic strategies plants use to defend themselves. In the first of those, German scientists studied a wild tobacco plant and found that when it is attacked by a caterpillar the plant releases a chemical that, in turn, attracts a predatory bug to eat the caterpillar. The production of the bug-attractant is triggered by the caterpillar’s saliva. Essentially, then, the caterpillar sets off an alarm that calls in predators to eat it. How cool is that?
A second study, done at the University of Missouri-Columbia, found that a species of mustard plant could detect the vibration signature of a caterpillar chewing on one of its leaves. When the plant identified that signal, it increased production of chemicals that make its leaves taste bad to herbivores. Researchers were able to replicate and reproduce the vibrations and trigger the response in the lab. They also showed that other kinds of vibrations did not cause the plants to defend themselves, so the chemical production appeared to be a direct response to herbivory.
These and other research projects help show that plants are not at all defenseless. Not only do they have strategies to make themselves more difficult to eat (toxins, spines, etc.), they can also respond when they are attacked. In prairies, there are numerous examples of plants defending themselves in interesting ways, including sunflowers that produce sweet stuff to attract predatory ants and grasses that increase their silica content under intensive grazing pressure.
Of course, herbivores have evolved their own tricks to counter all those plant defenses. Several insect species, for example, have developed ways to deal with the toxins produced by milkweed plants and happily munch away on leaves that would kill other insects. Now its the milkweed’s turn to (through natural selection and over many years) come up with a response to that response. The world is pretty fascinating, isn’t it?
So, the next time you’re walking through peaceful-looking prairie on a pleasant morning, remember that those little plants you’re crushing beneath your feet may not be as helpless as they appear. Sure, those plants are mostly fighting back against animals trying to eat them, but you may still find yourself an accidental victim of their defense strategies. Experienced hikers are well acquainted with the abrasive edges of grass leaves and the sharp spines on species such as roses and cacti. At one time or another, most of us have blundered into a patch of nettles or poison ivy.
No, plants are certainly not helpless. Let’s just be thankful they haven’t (yet) figured out how to chase us down.
A huge thank you to Chris Helzer for authoring this week's blog. Chris is The Nature Conservancy’s Director of Science in Nebraska. To enjoy more photos and discussions about prairie ecology, restoration, and management, follow Chris's blog "The Prairie Ecologist."
I have been a high school French teacher, registered piano technician, and librarian. In retirement I am a volunteer historian at Lee County Historical and Genealogical Society.