2017 Nachusa Grasslands Science Symposium Poster and Speaker Abstracts
Investigating Coyote Diet and Impact on Small Mammals in a Restored Prairie; Kirstie Feller, M.S. Candidate, Dept. of Biological Sciences, Northern Illinois University (email@example.com). Advisor: H. Jones (firstname.lastname@example.org)
Coyotes (Canis latrans) are one of the most prevalent predators in the United States. With the rapid decline and extirpation of apex predators, coyote abundance and geographic range have increased. Coyotes now fill the apex predator niche in many systems, but as omnivores, they differ from historical apex predators behaviorally and in diet. Thus, understanding coyote diet is important to better understanding their role in community function and structure. We conducted SIA (stable isotope analysis) on hair samples obtained from coyotes within a 2-mile radius of Nachusa Grasslands. In addition, we conducted small mammal sampling to evaluate the impact of mammalian predators on small mammal abundance and diversity. Preliminary results show that coyotes are omnivores, eating a wide variety of dietary items in approximately equal proportions. In addition, I will discuss the differences in small mammal abundance and diversity between exclosure and control plots.
Do Prairie Birds Provide Services or Disservices on Adjacent Conventional Farms?; Megan Garfinkel, PhD candidate, Dept. of Biological Sciences, University of Illinois at Chicago (email@example.com). Advisor: C. Whelan (firstname.lastname@example.org)
Restored and remnant prairies like those at Nachusa Grasslands provide ideal habitat for grassland birds, but they are generally surrounded by vast agricultural fields. Birds that nest in prairie fragments may forage in nearby corn and soy fields, and provide “services” or “disservices” in those fields by consuming either pest or beneficial arthropods. Birds have been shown to provide effective pest removal services in many agricultural systems, but most of those studies have taken place in “wildlife friendly” or tropical agriculture where bird density and/or diversity tends to be high. Very few studies have examined whether birds may provide services or disservices in temperate conventional monocrop systems. I conducted a pilot study in 2016 to determine whether birds affect corn or soy crop yield in an agricultural field adjacent to a prairie patch at Nachusa Grasslands. I used exclosures to examine the indirect effects of birds on crop yield, and a fecal DNA diet analysis to characterize the arthropod prey of birds caught on or near the cropped fields. Birds had a positive effect on corn yield, but a negative effect on soybean yield. I will use the diet analysis data to help explain these results. The results of this study suggest that grassland birds may have significant indirect effects even in industrial monocrop systems. Further study is needed to determine whether these effects may help to incentivize conservation of larger patches of prairie within the agricultural “matrix.”
The Effects of Bison Reintroduction on Grassland Birds in Tallgrass Prairie; Heather Herakovich, PhD candidate, Dept. of Biological Sciences, Northern Illinois University (email@example.com). Advisor: H. Jones (firstname.lastname@example.org)
Restoration projects have sought to increase the quality and size of prairie fragments, hypothetically increasing breeding habitat for grassland birds. Bison are now being reintroduced to prairie restorations as a final step in a complete restoration to increase habitat heterogeneity. The goal of this study was to understand how the immediate impact of bison influences nest survivorship, nest predators, and species composition of all grassland nesting birds, artificial nests, and migrant birds at Nachusa Grasslands in Franklin Grove, IL. We measured nest density and survivorship in four plantings and two remnant sites from May to July 2014, 2015, 2016, and 2017. We found 210 nests of fourteen different species and placed 320 artificial nests (80 per year) over the course of four breeding seasons. In addition, we placed acoustic recorders in each site twice during the breeding season to record the species present at each site. Bison reintroduction did not influence survivorship of grassland bird or artificial nests. Parasitism declined from 2014 to 2016, but did not influence survivorship. The species composition of birds did not overlap when comparing bison and non-bison sites, suggesting a difference in species composition between the two areas for June 2016. Complete analysis and more data is needed to determine how this reintroduction is impacting migrant and resident grassland birds.
Snake and Blanding’s Turtle Responses to Restoration at Nachusa Grasslands; Richard King, PhD, Associate Professor, Dept. of Biological Sciences, Northern Illinois University. (email@example.com)
Rich King1, John Vanek1, Dave Mauger2 (firstname.lastname@example.org), Tom Anton3 (email@example.com), Alicen Etheridge4, and Nathaniel Weickert5
1Northern Illinois University, 2Natural Resource Consulting, 3Ecological Consulting Group, LLC, 4Aurora University, 5Nachusa Grasslands
In this talk with two parts, we report positive responses of four species of grassland snakes and the state endangered Blanding’s Turtle to restoration efforts at Nachusa Grasslands.
Part 1: We monitored snake occupancy from 2013-2016 using coverboard arrays in 12 restorations varying in age from one to 25 years. Weekly coverboard checks resulted in 1,289 captures of 1,028 individual snakes belonging to four species; 139 captures of 112 Eastern Fox snakes, 436 captures of 348 Dekay’s Brown snakes, 106 captures of 89 Plains Garter snakes, and 608 captures of 479 Common Garter snakes. The number of restoration units occupied increased over time for all four species. Initial occupancy was positively correlated with restoration age for Dekay’s Brown snakes but not for other species. Their small size may limit the ability of Dekay’s Brown snakes to colonize recently restored sites. In contrast, larger, more mobile species may colonize more easily making restoration age less of a factor in their distribution.
Part 2: Blanding’s Turtles occur in small numbers in two wetland complexes at Nachusa Grasslands. Since 2014, 11 individuals have been captured and eight of these are being monitored using radiotelemetry. This has allowed us to discover and protect nest sites from predators and ensure hatchlings enter wetlands (2 nests and 11 hatchlings in 2016, 3 nests and 22 hatchlings in 2017). In 2017, juvenile Blanding’s Turtles were observed for the first time. Two individuals estimated to be 3-4 years of age were found in the Tellabs Savanna unit. Their age corresponds to the approximate date when known nesting areas were converted from row crop to restored prairie. Prior removal of encroaching woody vegetation from sedge-dominated wetlands also improved Blanding’s Turtle habitat quality.
Ornate Box Turtles (Terrapene ornata) Health Assessments: An Update including Characterization of Inflammatory Markers; Laura A. Adamovicz, DVM, PhD candidate, Dept. of Comparative Sciences, University of Illinois at Urbana-Champaign (firstname.lastname@example.org. Advisor: M. Allender (email@example.com)
Laura A. Adamovicz,1 DVM; Matthew C. Allender, DVM, MS, PhD, Dipl ACZM1; Sarah J. Baker, PhD2; Ethan J. Kessler2; Michael J. Dreslik, PhD2
1Wildlife Epidemiology Lab, Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802 USA
2Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana, IL 61802 USA
Ornate box turtles (Terrapene ornata) are considered near threatened by the International Union for Conservation of Nature (IUCN) and are listed under CITES Appendix II. They are also a species of conservation concern in Illinois. Relatively little is known about the health status and disease threats to the remaining ornate box turtle populations in Illinois. From May 6-8th 2016 and May 15-18th 2017 161 ornate box turtles were located in the Nachusa Grasslands using human and canine search teams. Health status was assessed using physical examination, hematology, plasma biochemistry, blood gas panels, protein electrophoresis, hemoglobin-binding protein assessment, and quantitative PCR for multiple infectious diseases including ranavirus, Terrapene herpesvirus 1 (TerHV1), Mycoplasma sp., adenovirus, and others. Most turtles evaluated were apparently healthy except for significant predator-related shell trauma. Shell injuries from burns were also documented. A relatively low prevalence of infectious disease was detected within this population, with TerHV1 identified most frequently. This presentation will summarize the results of a comprehensive ornate box turtle health assessment program, including evaluation of several markers of inflammation associated with shell trauma, and make evidence-based management recommendations for the box turtles living at the Nachusa Grasslands.
Butterfly Survey of Nachusa Grasslands; Wayne E. Schennum, PhD, Independent Scholar (firstname.lastname@example.org).
In 2017, 12 Nachusa units – 5 upland prairies, 4 wetlands, 2 savannas, 1 wetland/prairie restoration – were surveyed for butterflies on 12 visits from early May to late August. The presence and population size for all butterfly species observed were tabulated for each visit to a site. In addition, notes on the weather and ecological features were taken. Plant species surveys were also conducted to evaluate the floristic quality of each study site and the presence and population sizes of larval host plants for remnant-dependent (r-d) butterflies, those species restricted to native plant communities. Forty species were recorded during the survey, including 11 that are restricted to remnant prairies and wetlands. The most abundant butterfly observed was the Regal Fritillary (Speyeria idalia), a threatened species in Illinois. Found in all 5 upland prairie remnants and the prairie/wetland restoration, 473 was the total maximum count for this rare butterfly. Two additional r-d species, the Black Dash skipper (Euphyes conspicua) and Meadow Fritillary (Boloria bellona), had maxima of 27 and 19, respectively. The other 8 r-d species were observed no more than 10 times, and mostly less than 5. Previous surveys by Panzer and Nachusa volunteers found an additional 6 and 2 r-d species, respectively, but all were in very low numbers.
How Does Restoration Management Affect Flower and Bee Communities at the Nachusa Grasslands?; Sean Griffin, PhD candidate, Dept. of Applied Ecology, North Carolina State University (email@example.com). Advisor: N. Haddad (firstname.lastname@example.org) with Bethanne Bruninga-Socolar (email@example.com) and Jason Gibbs (Jason.firstname.lastname@example.org)
Important management methods such as prescribed burning and grazing primarily target restored plants and vegetation structure, but can also affect other native organisms present in a restoration. Management can affect these other restored organisms in two ways: either directly, by changing their survival or reproduction, or indirectly, by altering their interactions with the plant community. Over a five-year observational study, we examined how one critical group of pollinators, the wild bees, responded to management methods and landscape at the Nachusa Grasslands and separated the direct effects of management from those mediated through their floral resources. We found that though flowering plant communities were affected by restoration age and burning, bee community abundance and diversity responded primarily to the amount of surrounding prairie habitat in the landscape. These findings underscore the importance of large ecological restorations like Nachusa for protecting native organisms.
Dung Beetle Functional Traits Related to Restoration Management Practices in Tallgrass Prairie; Sheryl Hosler, M.S. candidate, Dept. of Biological Sciences, Northern Illinois University (email@example.com). Advisor: N. Barber (firstname.lastname@example.org).
Degraded ecosystems can be restored via wide-scale management practices. While restoration work often focuses on reestablishing species diversity and abundance, functional trait analysis is emerging as a more holistic approach to evaluating restorations. We examined the species composition and functional traits of dung beetle communities across a chronosequence of restored tallgrass prairie in Illinois, including sites with and without bison and prescribed fire. Data were collected on behavioral guild, diel activity, and body measurements, and were analyzed using generalized linear models. We also performed a dung decomposition experiment to measure an ecosystem function driven by these insects. Older restorations showed dung beetle functional richness and evenness more similar to remnant sites than new restorations. Restored sites with bison had greater functional richness and diversity of dung beetle species, as well as faster rates of dung decomposition, than similar-aged sites without bison. Prescribed fires interacted with the presence of bison on the functional richness, diversity, and dung decomposition performed by the dung beetle community. We conclude that measures of functional diversity are more appropriate for evaluating the success of tallgrass prairie restorations because they indicate the restoration of ecosystem functions, rather than simply the presence or absence of species. Our research also reinforces the value of dung beetles in evaluating ecosystem restorations. We recommend that restoration managers consider the arthropod community and its functional characteristics when making management decisions.
Vegetation Impacts of Reintroduced Bison in a Restored Tallgrass Prairie and Ability of UAV Imagery to Assess Them; Ryan Blackburn, M.S. candidate, Dept. of Biological Sciences, Northern Illinois University (Ryanbburn451@gmail.com). Advisor: H.Jones (email@example.com).
The effects bison have on remnant (never-plowed) prairie vegetation are well documented. However, there is little known about how bison will affect vegetation assembly in restored prairies. Remote sensing with unmanned aerial vehicles (UAVs) is used to identify changes within plant communities with increasing frequency but the limits of this are still unknown. The goals of this study were to 1) measure the impacts of bison reintroduction and restoration age on plant communities across a chronosequence of restored and remnant tallgrass prairies, and 2) determine the limitations of multispectral imagery in identifying the plant species or any differences in site greenness. During 2014 and 2015, bison were reintroduced to half of these sites. Plant surveys were conducted at each of the sites and compared to UAV surveys to assess multispectral performance. Vegetation indices were used to determine the uniqueness of individual species’ or plant groups’ spectral signatures. The sites’ greenness was determined using NDVI averages. Linear models were used to test for the impacts of grazing and restoration age on the plant communities. Plant diversity decreased with restoration age in sites with bison present. However, species richness decreased as a result of restoration age, regardless of bison presence. This suggests that plant communities are changing as the sites age and bison are impacting plant species relative abundances. The use of multispectral imagery may be limited to detect these changes. We found that certain species signatures were too similar to differentiate. The limitations of multispectral imagery for our purpose may be due to the amount of spectral bands available in the sensor. Hyperspectral imagery, which has hundreds of bands, may be much more effective at identifying small differences between species. Site greenness compared between restorations shows potential to monitor landscape level differences. These indices have been shown to be correlated with other traits such as foliar nitrogen. However, more information is needed to see if this holds true with this equipment. Despite these limitations, our results show that multispectral imagery has the potential to identify some species and other traits important for restoration. However, without the ability to identify most species, shifts in the community due to factors such as restoration age and grazing will be impossible to detect.
The ReFuGE Project: Restoring Function in Grassland Ecosystems; Nicholas Barber, PhD., Assistant Professor, (firstname.lastname@example.org) and Holly Jones, PhD, Assistant Professor, (email@example.com), Department of Biological Sciences, Northern Illinois University.
Ecosystems carry out a wide range of processes, including services that benefit people such as providing clean air, water, pollination of crops, and productive soils. These processes depend on diverse communities of plants, animals, and other organisms with a wide variety of traits – characteristics of plants and animals that shape how they interact in ecosystems. This project will examine how management actions in a restored grassland shape the species and trait compositions of plant and animal communities and the ecosystem processes that these species drive. We will focus on three landscape-scale management actions: reintroduction of mega-herbivore grazers (bison), large predator removal, and application of prescribed fires. The research will advance knowledge of community-trait-function relationships by including consumers in interactions spanning entire food webs and expanding to a relevant landscape scale. We will measure both traits and ecosystem function changes resulting from management actions in two food web modules. The first module includes plants and herbivores (insect and small mammal) and their impacts on primary productivity and litter decomposition through changes in plant traits and herbivore foraging specialization and the degree to which herbivores use a wide variety of food resources (niche breadth) as measured by stable isotopes. The second module is dung decomposers and their effects on soil processes (carbon and nitrogen cycling and decomposition rates) through changes in morphology, foraging strategies, and phenology. Ultimately this research will lay a ground work for studies manipulating the species- and trait-composition of consumer communities. Further, by performing this work in a restored system and in concert with managers, it helps close the loop between researchers and practitioners.
Restoration Management Influences Changes in Functional Composition of the Native Bee Community at Nachusa; Bethanne Bruninga-Socolar (PhD candidate, Rutgers University), Sean Griffin (PhD candidate, North Carolina State University), & Jason Gibbs (PhD, University of Manitoba).
Our work in 2013 and 2014 showed that plant-based restorations at Nachusa are successful at establishing bee diversity and abundance at levels that approach remnant prairie. However, the community assembly process by which bee species from a regional pool are sorted into restored habitats during colonization is not well understood: why do bee species occur in some sites but not others? In existing restorations, understanding the site-level habitat associations of bee species can shed light on the past community assembly process and inform restoration practice. Bee species are expected to occur in sites with characteristics that match up with bee species characteristics (functional traits). For example, bee species that require specific nesting resources are expected to occur in sites that have those nesting resources. We used data on bee specimens collected 2013-2016 at Nachusa to determine how bee species are distributed among a chronosequence of restored sites with different characteristics, such as time since the last burn. We divided bee species into two categories: those that nest in soil and those that nest in hollow stems or wood. We found that the percentage of soil nesting bees in the community is high soon after fire, but decreases with time after a burn. The percentage of stem nesting bees in the community is low after fire, but increases with time after a burn. As vegetation accumulates in the years after a fire, stem nesting bees have more hollow stems available in which to nest, whereas soil nesting bees experience more difficulty finding appropriate soil nest sites hidden among the vegetation.
Carex of Nachusa Grasslands; Linda Curtis, M.S. in Botany, Independent Scholar (firstname.lastname@example.org), www.curtistothethird.com)
The herbarium in The Nature Conservancy’s Nachusa Grasslands’ headquarters holds 47 Carex species as pressed and labeled specimens from Lee and Ogle Counties. New Carex species discovered during sedge season in June and July fieldwork were C. lunelliana, C. lurida, C. mesochorea, C. radiata and C. sprengellii in 2016. In 2017 new Carex were C. austrina, C. conoidea, C. echinodes, and C. frankii. Voucher specimens were sent to the state herbaria. Poster
Effects of Management on Functional Diversity in Restored Tallgrass Prairie Plant Communities; Anna K. Farrell, M.S. candidate, Dept. of Biological Sciences, Northern Illinois University (email@example.com). Advisor: N. Barber (firstname.lastname@example.org).
Although ecologists have traditionally studied communities by measuring species diversity and abundance, this approach struggles to identify general patterns that occur across many ecosystems. A more recent focus on studying communities through functional traits has clarified how species respond to environmental conditions that result from different management strategies. Functional traits are responsible for driving ecosystem functions, such as primary productivity and nutrient cycling, so shifts in management may alter ecosystem functions through changes in functional traits. Understanding the plant traits that drive ecosystem functions may allow restoration managers to better plan, predict, and reach restoration goals, such as high biodiversity, invasive species control, and high primary productivity. This study examines the functional trait composition of restored tallgrass prairie plant communities under different combinations of age, grazing, and prescribed fire management at Nachusa Grasslands. We also study relationships between functional traits and net primary productivity of each community. Bison grazing increases functional diversity, while prescribed burns decrease it. Net primary productivity increased with functional diversity, possibly resulting from better coexistence of species in similar niches due to complementary functional traits.
Floral and Soil Stoichiometric (C:N) Response to Prescribed Fire in Tallgrass Prairie; Jeff Heise, M.S. candidate, Dept. of Biological Sciences, Northern Illinois University (email@example.com). Advisor: H. Jones (firstname.lastname@example.org).
Prescribed annual burns have long been used in remnant and restored prairies to boost nutrient cycling and control unwanted species. Moreover, prairie grazers tend to prefer recently-burned sites, which is often termed pyric herbivory. Plant and soil stoichiometry, specifically C:N, can be used to quantify the quality of the resource for grazers (plants) and microbes (soils). While the impacts of fires on soil and plant stoichiometry are known in old field prairies, little research has been done in more recently-restored ecosystems, especially those with newly-reintroduced grazers. This study examined how prescribed burns have affected plant community composition and plant and soil stoichiometry (C:N). We used matched pairs of burned and unburned sites with similar restoration ages. The first pair were restored in 2007 and 2008, and the second pair were restored in 2001 and 2002. Three soil samples and 55 plant samples were taken from each planting. Soil samples were sieved and analyzed for total carbon and nitrogen using a mass spectrometer. Three individuals of each plant species were collected, dried, homogenized, and also analyzed for total carbon and nitrogen. Data were analyzed using general linear mixed models. The data show a significant decrease in the C:N ratio for C4 grasses after prescribed fire, which is due to their capacity for late season growth and bloom. The C:N ratio for C3 forbs increased, indicating a lower quality resource. C3 grasses, legumes, and soil showed no significant change.
Plant Diversity and Composition Do Not Influence Soil Nitrogen; Drew Scott, M.S. candidate, Dept. of Plant Biology and Center for Ecology, Southern Illinois University (email@example.com). Advisor: S. Baer (firstname.lastname@example.org).
Diverse plant communities are predicted to utilize more soil nitrogen (N) than less diverse plant communities. This predicted nutrient use complementarity was tested using 5 restorations (10-12 growing seasons) at Nachusa Grassland. Six high- and low-diversity sampling frames were established in each field based on a preliminary vegetation survey. Soil ammonium-N, soil nitrate-N, total extractable soil N, and plant composition were measured. Soil N variables were examined with linear mixed models, PERMANOVA, and redundancy analysis. Plant diversity did not cause differences in soil N. Soil N was also not related to plant composition. These results contradict predictions from ecological theory and support from observational and experimental studies. Perhaps differences in diversity need to be sustained over large spatial scales or perhaps previously observed effects have been misattributed to diversity.
The Effects of Invasive Plant Removal on Small Mammals; Nick Steijn, M.S. candidate, Dept. of Biological Sciences, Northern Illinois University (email@example.com. Advisor: H. Jones (firstname.lastname@example.org).
Small mammals, defined as less than 500 grams, include mice, voles, shrews, and squirrels. They are ubiquitous and can occur at very high population densities. They are important players in terrestrial food webs, since they eat insects, plants, fungi, and seeds. Invasive plants produce large quantities of seeds, and their removal may significantly impact small mammal populations. At Nachusa Grasslands, invasive plant removal is a core management practice usually accomplished by spraying herbicides. The goal of this research is to understand how herbicide spraying affects small mammal populations. I hypothesized that 1) herbicide spraying would reduce seed abundance and diversity, and 2) sites that were sprayed would have lower small mammal density and diversity. To this end, I am continuing the small mammal monitoring project initiated by Dr. Holly Jones (Northern Illinois University) in 2013. In addition to this mark-recapture study, I sprayed red clover (Trifolium pratense) with herbicide in half the small mammal sites from June-July. Red clover is a common invasive species whose large seeds are consumed and dispersed by small mammals. From October 2016 to August 2017 we captured an additional 428 small mammals, and next I will compare the density and diversity of communities in sprayed and unsprayed sites. I also placed pitfall seed traps throughout certain sites to compare sprayed vs. unsprayed seed rain; preliminary results will be presented at the symposium. This research will inform site managers about the short- to mid-term impacts of herbicide spraying on small mammal communities.
Range-Wide Variation in Floral Traits and Local Pollinators in Downy Paintbrush (Castilleja sessiliflora, Orobanchaceae), and Implications for Restoration at the Range Edge; Katie Wenzell, PhD candidate, Dept. of Plant Biology and Conservation, Northwestern University (KWenzell@u.northwestern.edu). Advisors: K. Skogen (email@example.com) and J. Fant (firstname.lastname@example.org).
Species often vary across their geographic ranges, and this may be more pronounced within widespread species. Geographic variation in traits may reflect differences in local selection and drift. Variation in floral traits may reflect selection by local pollinators or other factors, which may have implications for reproductive success and persistence of plant populations. Here, we document geographic variation in floral traits across the range of downy paintbrush (Castilleja sessiliflora) and pollinator visitation to these populations. Floral color and morphology were found to vary across the range, as did pollinator assemblage. Overall, the total number and diversity of visiting pollinators decreased markedly toward the northeastern range extent (in northern Illinois).
Special attention is given to populations in Illinois, at the eastern range edge of the species. Downy paintbrush is threatened in the state, where it has been included in prairie restoration efforts, including at Nachusa Grasslands. To investigate factors that may influence the success of such restorations, we compare pollinator visitation, genetic diversity, and fruit set between a natural population at Illinois Beach State Park, and a restored population at Nachusa Grasslands. No pollinator visitation was observed at either site in 2017, and fruit set was generally low. However, preliminary investigations showed fruit set may be significantly higher at a remnant population at Nachusa compared to the nearby restoration. Further investigation is needed to indicate whether this pattern is consistent, and if pollinator visitation may drive differences in reproductive success between restored and remnant populations of downy paintbrush in Illinois.