This is a guest blog written by Beau Larkin and Ylva Lekberg. Jim and I were excited they chose our property as one of their research sites.
Often prairie restoration is to change agricultural fields into native prairie habitat. We can evaluate progress by comparing the restored plant community to a remnant prairie. It is relatively easy to measure this with plant communities, but this does not reveal what has happened belowground.We want to know if soil microbes become more similar to remnant prairie after restoration. We collected soil from cornfields and remnant prairie to characterize the microbial communities in these habitats. These represent endpoints along a gradient from degraded to desirable habitat. Then we sampled soil from restored prairies that differ in the amount of time since restoration began. If soil microbes in restored prairies become more similar to those in remnant prairie over time, then older restoration sites should be more like remnant prairies. On the other hand, if soil microbes remain similar to those in cornfields regardless of time since restoration, then restoration is only partly successful and the stability and function of these communities may be compromised.
If soil microbial communities do not shift to become more like those in remnant prairie, what are the consequences for restoration? Many restoration managers have noticed that grasses increase after treatment at the expense of forbs. Many variables could cause this to happen. Seed mixes that favor grasses, and frequent burning since restoration could cause this phenomenon. Some grass species are more competitive than others, and post-restoration overseeding also affects the resultant plant community. Amid the “noise” restoration and management history, there may be another explanation for the enhanced competitive nature of grasses in restored prairie. Because corn is more closely related to common prairie grasses than it is to forbs, is it possible that the soil community will favor these grasses. Working with Mike Healy from Adaptive Restoration, we collected plant cover data along with our soil samples to investigate how changes in plant communities correlate with soil microbial communities. In older restored fields that contain many forbs, we should find that the soil communities resemble those in remnant prairies. In restored prairies that reverted to high grass cover, we may find that the soil communities remained “stuck” in a condition similar to a cornfield. This situation might suggest that restoration projects should contain some mechanism to inoculate soil with microbes found in remnant prairie. We will attempt to disentangle the management histories and discover whether such a microbial signal exists. As results from this project come in, we will share what we learn with you.
Beau Larkin and Ylva Lekberg are both staff at MPG Ranch, which promotes conservation through restoration, research, education and information sharing. Beau is also an adjunct professor at University of Montana in the Department of Ecosystem and Conservation Sciences (DECS).
Seed Sourcing for Restoration in a Changing Climate
I had the opportunity to attend a Seed Sourcing Symposium at the Chicago Botanic Gardens on June 13. It was an important meeting and just the beginning of a very important discussion. The meeting moved from historical aspects of seed sourcing to current day projects to needed future actions. As promised, the day led to more questions than answers. I was surprised to learn organizations, government entities, and large institutions were focusing and directing resources to this topic. I’ll provide some highlights from the speakers. Check out the Native Seed and Plant Sourcing paper for indepth information on this topic.
Seed sourcing is the process of deciding which native seeds or plants will germinate and survive where you are planting them.
Historically, the native seed zones were created to limit movement of seeds; the goal was to prevent genetic maladaptation. When compared to current climate data, the 1960-1990 data used to create these maps is showing measurable differences. Climate change is happening quicker than we expect. The result is expected to be increases in extremes; for example, heat waves are expected to increase by 60% and increase in duration. Perhaps we need dynamic seed zones rather than the current static ones. Some work has been done to create provisional seed zones for the western part of the U.S.
What used to be “how local is local” has changed to “is local still local.” Speakers stressed the need to think ecologically when choosing species and sources. Latitude is an important component of ecologically-relevant seeds, especially as we consider climate change, which cannot be ignored.
Can we rely on adaptive evolution to rescue our wild populations from climate change? Can pollinators keep up with flowering evolution? Research is being done using trees in the northwest but we were cautioned that one species example cannot be extrapolated to another.
Commercial native seed companies were represented. They expressed a need for scientific evaluation of seed genetics. At present, their source identification is on the honor system. Native seed is not sold based on genetic standards; it is seed collected from native populations where no genetic testing of parent material has been conducted. It was emphasized that we are not able to genetically pinpoint a species. There is no historical genetic data on plants. We know genetic material is moved about via insects; we also know it is moved by bacteria and fungi.
Jack Pizzo, a commercial seed producer, used the analogy of Dr. Frankenstein to describe our current restoration practices. We take all these disparate parts with huge variability and put them together to recreate an ecosystem. These puzzle pieces are not static nor are they well studied. What is science and what is opinion when specifications of provenance for projects are written for commercial suppliers? Supply and demand must be considered. Is the demand for certain provenance, which may or may not be “genetically appropriate” keeping up with the economic realities?
A couple of presenters encouraged folks to “poke holes” in current practices. Not as a way to negatively criticize but as a way to “make it better.” Playing devil’s advocate and rethinking restoration practices is imperative and should be encouraged. Nature isn’t static. Nature doesn’t have a rote schedule. Neither should we.
The Bureau of Land Management (BLM) has established a National Seed Strategy for Rehabialition and Restoration; the success of this is based on “a nationwide network of native seed collectors”—from private individuals to organizations. The ultimate goal is to preserve our native seed stock and develop driven seed zones for each plant and tree which can be used for seed transfer. Our current use of serendipity rather than strategy backed with scientific evidence will not create resilient ecosystems. “We need the same forward-thinking management we demand for other natural resources such as timber and oil,” states Peggy Olwell, BLM.
While the BLM has initiated the first steps to preserve and protect our native seed sources, they readily admit that making sure the “right seed is in the right place at the right time” is the responsibility of the practitioner. And gaps in getting the information from the scientific community to the practitioner cannot be denied.
Projects already initiated:
Natural Selections – The Natural Selections Program develops high quality, genetically diverse, regionally adapted native seed for prairie and wetland restorations.
Prairie on Farms – Tallgrass Prairie Center has begun a new project to share knowledge of prairie reconstruction and management techniques with rural landowners.
National Seed Strategy – Their mission is to ensure the availability of genetically appropriate seed to restore viable and productive plant communities and sustainable ecosystems.
Seed Zone Summit – The northeastern area of the Forest Service will be holding this summit in 2017 to develop seed zones, develop guidelines for their use, and define terminology. The date and location are to be determined.
Commercial seed producers need to unite and create a native seed organization that represents the interests of those producing, sourcing, and planting native seeds. At present, there is no political voice or educational component for this industry.
We need direct funding for plants in our federal, state, and local budget. The BLM has no direct funding for plants at present.
We need educational forums to connect the science to the practitioner. This is often lamented in restoration but was specifically noted with regard to seed sourcing and understanding of “genetically appropriate” plant materials.
Think Like a Seed
Our management plan is simple: remove the invasives and increase diversity. One way we increase diversity is by propagating plants and planting them into various areas. How many we plant out in a year varies. It depends on my success rate at getting the native seed to germinate and then how many plants survived the overwintering process. Every year is different.
Growing these plants has taught me a great deal about them. Not only about the individual plant but about how to think like a seed. Seeds have many ways to stimulate and delay germination. In the restoration world, we are amazed at how certain plants are abundant during certain years. If we are tracking the weather (temperature, rainfall, etc) we might find a few clues about why those plants are enjoying that particular year. It’s not all weather related though. Anthropogenic reasons must be included especially knowing what type of disturbance might have occurred. At our place, storms also create disturbance when trees are toppled.
Understanding how to propagate requires an understanding of how the seeds germinate and a base concept of seed dormancy. Dormancy is how a seed protects itself from sprouting up at times when it isn’t conducive to their continued existence, such as in the middle of a cold, snowy winter. Seeds are regulated by chemicals, hormones to be exact, that determine their dormancy requirements and their germination requirements. This physiological dormancy allows for flexibility, which is advantageous since nature is not predictable.
The first rule for germination is to create the environmental conditions required for the seed to germinate. Initially, I had to learn what it takes to penetrate the seed coat to get moisture inside to the embryo; they must take up liquid faster than they lose it. This very basic rule is the most important. It is why the substrate that you put the seed into for germination is critical and it drives the pre-germination process, too, explaining why most native seeds require a cold, moist period of time rather than simply a cold one. There are a number of seeds that need more intensive procedures, such as alternating from warm to cold to warm with each temperature period requiring a certain number of days. Chemically altering the seed coat can be effective as well. I have successfully used Giberellin Acid (GA-3), a natural plant hormone, to induce germination. Not every seed responds to this though. To know which do, check out the Deno books in the Resource section of Propagation – My Set up and Methods. There are a few other sources listed here that I reference, too.
Just about every aspect the seed determines their germination requirements: small seeds, location of the seed on the plant, and time of seed maturation. The environment under which the plant grew will affect the seed: temperature, light, day length, drought, and soil nutrients. There are many variables that determine germination and dormancy. I think this is why I’m always surprised, amazed, awed when I’ve successfully gotten a seed to sprout!
Here’s a few of the books that I reference often when I have questions about seeds:
Fenner, Michael and Ken Thompson. 2005. The Ecology of Seeds. Cambridge UK: The Press Syndicate of the University of Cambridge.
Loewer, Peter. 1995. Seeds: The Definitive Guide to Growing, History, and Lore. Portland, OR: Timber Press.
Young, James A. and Cheryl G. Young. 1968. Collecting, Processing, and Germinating Seeds of Wildland Plants. Portland, OR: Timber Press.
Spotted Knapweed (Centaurea maculosa)
One section of our land has a large infestation of Spotted knapweed (Centaureamaculosa). Much like I handled the research for the cool season grass and bindweeds, I did the same with this. Hopefully, this will help others who have problems with this invasive.
Spotted knapweed, Centaurea maculosa, was introduced to America via contaminated alfalfa and clover seed in the 1890s; it made its way to Canada in 1893. It is considered the “most problematic invasive species in North America” (Emery et al. 2005).
Aside from being an invasive species, which takes the place of native species who host our insects, spotted knapweed contributes to soil erosion, surface runoff, degradation of soil and water, reduces biodiversity, reduces wildlife habitat, and alters the ecosystem processes. Soil erosion and runoff are because the taproot and lateral root networks replace the connected systems of native plants.
While enjoying dry, disturbed sites, Spotted knapweed is not drought tolerant. In years of low rainfall, a population will decrease. Of course, there is an opposite effect in years of good moisture. This plant doesn’t seem too particular about the soil types and can adapt to most any type of soil.
Seed Viability and Germination
The seeds are long-lived and durable because their hulls don’t easily decompose. In the soil, Zouhar (2001) found buried seeds remain viable after 5 years. They germinate in light or dark but rarely when 2” or more below the soil surface. They germinate under a wide temperature range — from 44°F – 93°F (Schirman 1981). While the seeds might germinate under a shady canopy, the adult plants will not survive without full sun.
The seeds of spotted knapweed germinate in 3 ways and each plant can produce seeds that fit each of the categories:
Nondormant, meaning they germinate in the dark
Light-sensitive, meaning they need exposure to red light to germinate
Light-insensitive, meaning they do not germinate with red light
Here’s a scary fact. Schirman’s (1981) study had 8 to 40 stems in a 5” hoop area, depending on the year. His research found “survival of only about 0.1% of the seed produced is required to maintain the stand at the level we observed” (Schirman 1981). Egads!! Newly established populations will expand faster than older ones (Emery et al. 2005).
Seeds are dispersed in a number of ways. If there is no external assistance, such as wind or wildlife, the seed will remove itself from the seedhead and land 3-4 feet from the original plants; they do not overwinter on the plant (Zouhar 2001). Often they are carried to other locations by vehicles, water, shoes, and excrement of mammals and birds. Spotted knapweed seeds can remain viable 7-10 days after they are eaten by deer (Zouhar 2001).
Facts about Spotted Knapweed
Short-lived perennial or biennial, living up to 3-9 years – this duo-classification is because the plant can live as a rosette for years before completing it life cycle or it can take only a single year. It’s plant specific.
Stout taproot generates lateral shoots creating a fibrous mat of roots that can extend for several feet
Plants regrow from the bud/root crown – this must be killed in order to kill the plant
Produce 1,000 – 20,000 seeds per plant per year; precipitation is a major factor in this (NRCS, Sheley et al. 1998)
About 90% of seeds are viable; can remain viable in the soil for 5-8 years
Have spring and fall growth periods
Older plants can have multiple rosettes and multiple blooming stems
Is in the Asteraceae family
Allelopathic – leaves and shoots exude cnicin.
Control based on Studies
Control of spotted knapweed requires management techniques tailored to all the plant’s life stages. No single treatment is the “magic bullet” but rather a combination of treatments needs to be part of the protocol. Two researchers found that knapweed would “increase to untreated level by the 6th year after single herbicide treatments” (MacDonald et al. 2013).
The brand Progeny has provided an effective treatment. We use a 3% solution (8 oz for 2 gal of water) and foliar spray. We have also effectively used a 20% solution (64 oz for 2 gal of bark oil).
Hand pulling is necessary for mowing and herbicide treatments to be effective but is not sufficient on its own. A “substantial” reduction of spotted knapweed was made after three years of hand pulling coupled with mowing or herbiciding (MacDonald et al. 2013). It is imperative that when pulling that the root crown and top 3” of the taproot is removed (Panke et al. 2012). If there are flowers present at the time of pulling, these plants need to be removed from the site as they can continue to produce viable seed (Panke et al. 2012). Spotted knapweed has also been known to cause skin irritations in some folks; be sure to wear the proper protection on your hands, arms, and legs. Hand pulling can stir up seeds in the soil and cause germination. One would want to recheck the area in the same growing year.
The season of mowing is important. Mowing during the bud or flowering stage reduces the number of plants and reduces seed germination (Rinella et al. 2001). A single mowing when the plant was in bud or bloom was ineffective; two years of fall mowing did not have much effect but three years of fall mowing decreased the adult population (MacDonald et al. 2013, Rinella et al. 2001). There is no data available on how many years of mowing is needed to control an infestation (Panke et al. 2012).
Burning was the least effective regardless of other treatments used. Stands of spotted knapweed do not carry fire well (Emery et al. 2005). The fire needs to be hot enough to kill the root crown. According to Sheley and colleagues (1998), fires may actually create the environment where spotted knapweed can thrive rather than knocking it back. A literature review found that “in 80% of the studies prescribed burning either increased or had no effect on” knapweed (Emery et al. 2005).
Those who did burn found it requires a very specific timing, frequency, and sufficient fuel loads (MacDonald et al. 2013). Early spring burns were ineffective and fall burns increased germination success. Summer burns when flowering would reduce an infestation if the fire is hot enough. MacDonald and colleagues’ (2013) learned there were more seedlings after a fire that burned at less than 320°F, which this research considered a low-intensity fire. If there was a small patch, possibly a handheld propane torch would produce an intense enough fire to kill the plant. Annual summer burns were the most effective but it’s difficult to get the proper fuel loads to create a hot enough burn with annual burning and annual burns have substantial collateral damage to native biota. Alternating burn years increases plant’s reproduction.
Grazing can have a negative effect on the plant. The rosettes are tasty and nutritious but are low growing making it difficult for cattle to eat. Second-year plants are fibrous and not very tender. Sheep are the more appropriate grazers as they eat the first- and second-year plants without issue (Sheley et al. 1998). I found no studies that quantified this success.
Biological control seems to be well known for this plant but, I am skeptical of introducing insects that are not native to this area. One study shows after the release of several species, the seed output was reduced and roots were damaged but the density of the plants were not altered (Rinella et al. 2001). There are 12 known insects species that are used for biocontrol; their purpose is to stress the plant with the hope the surrounding native plants can outcompete it (Sheley et al. 1998). Caution is urged in using biocontrol as it means introducing a non-native insect. As I’m fond of saying, two non-natives don’t make a native.
Carpinelli, Michael. Spotted Knapweed. Plant Conservation Alliance’s Alien Plant Working Group Least Wanted.
Czarapata, Elizabeth J. 2005. Invasive Plants of the Upper Midwest. Madison, WI: University of Wisconsin Press.
Davis, Edward S., Peter K. Fay, Timothy K. Chicoine, and Celestine A. Lacey. 1993. Persistence of Spotted knapweed seed in the soil. Weed Science 41: 57-61.
Emery, Sarah M. and Katherine L. Gross. 2005. Effects of timing of prescribed fire on the demography of an invasive plant, Spotted knapweed. Journal of Applied Ecology 42: 60-69.
Jacobs, James S. and Roger L. Sheley. 1998. Observation: Life history of spotted knapweed. Journal of Range Management 51(6): 655-673.
NRCS Pest Management – Invasive Plant Control. 2007. NRCS Conservation Practice Job Sheet MN-797.
MacDonald, Neil W., Laurelin M. Martin, Corey K. Kapolka, Timothy F. Botting, and Tami E Brown. 2013. Hand pulling following mowing and herbicide treatments increases control of Spotted knapweed. Invasive Plant Science and Management 6: 470-479.
Panke, Brendon, Ryan deRegnier, Mark Renz. 2012 Management of invasive plants in Wisconson: Spotted knapweed. University of Wisconsin Extension Publication A3924-13.
Rinella, Matthew J., James S. Jacobs, Roger L. Sheley, and John J. Borkowski. 2001. Spotted knapweed response to season and frequency of mowing. Journal of Range Management 54(1): 52-56.
Schirman, Roland. 1981. Seed production and spring seedling establishment of Diffuse and Spotted knapweed. Journal of Range Management 34(1): 45-47.
Sheley, Roger L., James S. Jacobs, and Michael F. Carpinelli. 1998. Distribution, biology, and management of Diffuse knapweed and Spotted knapweed. Weed Technology 12: 353-362.
Zouhar, Kris. 2001. Centaurea maculosa. In Fire Effects Information Ssytem, U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.
Monitoring and Management—a sensible pairing
This article was written by Beth Goeppinger, WI DNR Naturalist at Richard Bong State Recreation Area. It demonstrates how important monitoring is to our management practices.
Richard Bong State Recreation Area is a heavily used 4,515 acre property in the Wisconsin State Park system. It is located in western Kenosha County. The area is oak woodland, savanna, wetland, sedge meadow, old field and restored and remnant prairie. Surveys of many kinds and for many species are done on the property—frog and toad, drift fence, phenology, plants, ephemeral ponds,upland sandpiper, black tern, grassland and marsh birds, butterfly, small mammal, waterfowl, muskrat and wood ducks to name a few. Moths, except for the showy and easy-to-identify species, have been ignored.
That is until volunteer moth surveyor, Steve Bransky, came onto the scene. Steve had done a few moth and butterfly surveys here and there on the property. But that changed in 2013. Armed with mercury vapor lights, bait and a Wisconsin scientific collector’s permit, along with our permission, he began surveying in earnest.
He chose five sites in woodland, prairie and savanna habitats. He came out many nights in the months moths might be flying. After finding that moth populations seemed to cycle every 3-5 days, he came out more frequently. His enthusiasm, dedication and never-ending energy have wielded some surprising results. Those results have in turn, guided us in our habitat management practices.
Of the 2,000 moth species found in the state, Steve confirmed close to 700 on the property, and he isn’t done yet! He found one of the biggest populations of the endangered Papaipema silphii moths (Silphium borer) in the state as well as 36 species of Catocola moths (underwings), one of the densest and most diverse populations in the state. Six confirmed state records, over one hundred range extensions and over sixty county records make the monitoring even more impressive.
So what does all that have to do with management? Obviously the way we have managed in the past has created appropriate habitat for these species. Mowing and prescribed burning and invasive species removal is our management regime. We try to burn each habitat unit on a three-year cycle but due to budgets and weather that often turned into 5-7 years which as it turns out, was beneficial to the insects.
There has long been a balance in prescribed burning, native habitat must be maintained and burning is the most efficient way to do that but you also don’t want to burn too much and negatively affect the insect life. What the monitoring has helped us do is change and fine-tune our management strategies to better benefit the insects as well as the habitat.
We now make sure we have unburned habitat around the edges for recruitment. We mow some of the higher quality remnants more frequently than we burn them. We will also purposely try to leave unburned spots around host plants in places these populations are or could be. The monitoring data has also affected our brushing decisions for instance, Catocala crataegii (Hawthorn Underwing) needs hawthorn, which is present but not in large numbers. To that end, we are focusing on planting and keeping larger blocks of hawthorn.
They say that knowledge is power and I think that is true. We were lucky before in our management but now that we know the amazing diversity of moths on the property, we can consciously and effectively manage for all the resources. You have to know your site, whether it’s birds, plants, mammals or insects before you manage it, not just burn it all. Now, I realize not everyone is lucky enough to have access to a moth expert but perhaps you could contact a local university or museum or resource expert to do some monitoring, or you could bait and take photographs for identification. Just get out there and collect data to help guide your decision making, it makes good sense.
Note: Steve Branskey is a member of Wisconsin Entomological Society
Savanna Prairie Planting
Whew!! It’s been 2 years of preparing and planning but the last 12 acres were finally planted on Dec 13, 2014!! This is our third and last planting for the Driftless Prairies! We had hoped this one would go smoothly since the other two did not, but our record remained and we had plenty of stress!
Two years ago we began the process of creating a maintenance path around the area we would plant to prairie. With this, we ended up with space between the path and the adjacent wooded areas. We also had some neighboring land that we were allowed to remove invasives beyond our property line. We planted all this area before the actual day of the prairie planting. Since edge management is what we spend a good deal of time on, this will certainly help to expand this area and create fewer problems with the encroachment of invasive plants.
We planted a total of 144 species throughout. We’ll be mowing it a couple of times next year and if the foxtails come in as they have with the other plantings, we’ll be able to burn in the 2nd year. By the 3rd year, we hope to see more of the plants pop up and fewer weeds.
Our goal, with the restoration of this property is diversity. Everything we do is about diversity. Having a diverse assortment of native plants, native trees, and native bushes brings with it a diversity of animals, birds, and insects. The key word in that sentence is “native.” A diversity of non-native, invasive plants decreases the diversity of all other life because our native vertebrates and invertebrates haven’t evolved to use those plants.
To read more about the planning process and see pictures on the actual day of the planting click here.
Many thanks and appreciation to the many people who helped with this planting. Not just the day of the planting, but the years that led up to that event!!