Source: UNIVERSITY OF FLORIDA submitted to
GEOGRAPHICAL AND ECOLOGICAL CONSTRAINTS ON RECRUITMENT OF WIREGRASS, AN ESSENTIAL COMPONENT OF LONGLEAF PINE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1025046
Grant No.
2021-67013-33618
Cumulative Award Amt.
$500,000.00
Proposal No.
2020-04365
Multistate No.
(N/A)
Project Start Date
May 1, 2021
Project End Date
Nov 30, 2025
Grant Year
2021
Program Code
[A1102]- Foundational Knowledge of Agricultural Production Systems
Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611
Performing Department
Forest Resources and Conservation
Non Technical Summary
Wiregrass (Aristida beyrichiana) is an essential driver of the vegetation-fire feedback that promotes the ecological health of imperiled longleaf pine (Pinus palustris) savannas of the southeastern USA. A concerning limitation to widespread wiregrass restoration is the potential for populations to be adapted to local environmental conditions (ecotypes) that affect plant performance and seed storage capacity. This constraint severely limits where seeds can be sourced and how they can be stored for restoration. Our long-term goal is to expand restoration capacity by identifying mechanisms limiting establishment of sustainable wiregrass populations from seed sourced from different environments. We propose to: (1) Determine whether seeding rate and/or presence of novel competitors limits ecotype performance; (2) Identify whether endomycorrhizal fungi and/or water availability affect ecotype performance; and (3) Test whether ecotype seeds differ in viability, morphology, or physiology, which will inform long-term seed storage capacity. We will reciprocally sow seeds adapted to wet or dry environments in the field and quantify their performance (i.e., vital rates) and mycorrhizal associations. We will also determine seed viability and desiccation and aging tolerance of each ecotype.This project provides specific support for priority needs for foundational knowledge in agricultural production systems, additionally addressing goals of the USDA NRCS Longleaf Pine Initiative and the USDA-supported National Native Seed Strategy. We seek to advance our knowledge of complex, fundamental mechanisms that underlie biotic constraints to widespread, sustainable ecosystem restoration. Research outcomes will help optimize the time and money invested across a broad geographic area, maximizing returns on this investment.
Animal Health Component
20%
Research Effort Categories
Basic
80%
Applied
20%
Developmental
0%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1360780107075%
1360780110225%
Knowledge Area
136 - Conservation of Biological Diversity;

Subject Of Investigation
0780 - Grasslands, other;

Field Of Science
1070 - Ecology; 1102 - Mycology;
Goals / Objectives
The long-term goal of this project is to expand the capacity for wiregrass seed to be used for restoration of longleaf pine savannas of the southeastern United States. To support this goal, we need to determine mechanisms that limit the establishment of sustainable wiregrass ecotypes in different environments, including wet and dry soil types, and determine best practices for storing seeds. This study will address the following fundamental objectives:1. Determine whether wiregrass seeding rate and/or the presence of novel competitors affect wiregrass ecotype success (i.e., establishment probability);2. Identify whether the presence and abundance of endomycorrhizal fungi or the availability of water limit wiregrass ecotype success; and3. Test whether seeds of wiregrass ecotypes differ in morphology, quality, viability or desiccation and aging stress tolerance, which will inform long-term seed storage physiology.
Project Methods
Objective 1In Year 1, we will establish common gardens in both a wet and dry environment, each with at least 30 acres available for blocking. Wiregrass ecotypes from each environment will be reciprocally seeded in each soil environment. Both common gardens will be divided into eight approximately equal blocks (~3.75 acres/block) and assigned to a home (ex., dry seeds in dry soil) or away (ex., dry seeds in wet soil) seed treatment. Seeds will be sowed at 2 lbs/acre across the entire field, and we will establish buffers for blocks, but because this isrestoration in practice, there won't be destructive plow lines between blocks.Within each block and environment, we will test a combination of seeding rates and the presence or absence of novel or home competitors. Two of six 10m x 10m subplots in each block will be randomly assigned to each of three seeding rates (low,typical, high). Within one of each of the seedling rate subplots, non-wiregrass competitors will be removed weekly. When possible, seedlings will be carefully pulled to reduce soil disturbance, and avoid damaging the root systems of wiregrass.In each treatment, we will measure wiregrass vital rates in 4m x 4m plots situated in the center of the 10m x 10m subplots that receive the treatments. Every four months we will count the number of germinated seedlings to calculate the probability of transitioning from sown seed to emerged seedling. We will mark every seedling to prevent any errors in data collection resulting from double-counting seedlings. During fall of Years 2 and 3, we will measure size, survival, and fecundity of all individuals in subplots.We will sample the plant community to characterize novel or home competition for each level of seeding rate. Within 4m x 4m subplots we will record the species name for each individual, count the number of stems, and estimate percent cover.We will use two methods to examine wiregrass ecotype success with varying levels of seeding rate and competition. First, we will run a set of Cox proportional-hazards models using the number of seedlings surviving at each sampling event as the response variable, and environment (i.e., dry and wet), seed origin (i.e., dry and wet), seeding rate (i.e., low, typical, and high), and presence of novel or home competitors (i.e., novel, home, none) as independent variables. Block and subplot ID will be used as random effects. Second, we will estimate transitions between life stages between time steps using a Bayesian continuation ratio model.Objective 2Within each of the eight blocks at the two sites (wet and dry), we will establish three 10m x 10m subplots and that received a typical seeding rate and are at least 10m away from other treatment subplots. The subplots will be randomly assigned to three treatments: 1) unmanipulated, 2) fungi removed via regular application of a broad-spectrum fungicide (e.g., Benomyl), and 3) soil moisture increased via regular addition of untreated water. Because the addition of a liquid fungicide also increases soil moisture, the water addition treatment is needed to calculate effect sizes.During every year, we will haphazardly select 5 of the unmarked wiregrass seedlings and we will collect a soil core in the center of each wiregrass individual and extract root samples. Root samples will be stored in a 70% ethanol solution and sent to the UF Soil Microbial Ecology Core Lab along with the soil core samples. There, root samples will be tested for mycorrhizal root percent colonization and spore count. In addition, soil samples will be run through polymerase chain reaction to determine fungal species present in each sample.We will use the same two methods of analyzing survival over time and transition between life stages over time to examine wiregrass ecotype success with differences in water availability and the presence or absence of fungi. Note that as stated in the methods, the addition of fungicide as a treatment also adds soil moisture. Thus, we will need to use effect sizes (i.e., log-response ratios) when determining whether water or fungi alone have significant effects on colonization rates or spore counts of mycorrhizal fungi.Because the ability to associate with endomycorrhizal fungi can differ between ecotypes, we will test differences in fungal communities associated with dry or wet ecotypes and root colonization in the unmanipulated, fungicide, and the water addition treatment. We will adopt a multivariate approach to investigate patterns in endomycorrhizal communities using Bray-Curtis similarity index. We will test whether fungal communities in each root sample are more similar to the communities within the same combination of wiregrass ecotype and subplot treatments than those in different wiregrass ecotype or subplot treatments using a Permutational Multivariate Analysis of Variance.Objective 3We will collect seeds from plants occurring at a dry site and wet site. Wiregrass typically sets caryopses, referred to hereafter as seeds, by October and sheds seeds by late November or early December. We will harvest randomly selected seeds from a minimum of 50 haphazardly selected, widely spaced plants (> 3 m) approximately midway through development as well as at the point of seed shedding.We will commence experimentation within two weeks of harvest.We will assess seed morphology and initial seed quality, on an individual seed basis, using multi-spectral imaging. We will use immature seeds (minimum n =100) to quantify size and shape and a precision balance to quantify seed weight.For seed viability, we will use the same sample size of seeds to non-destructively generate baseline chlorophyll fluorescence (CF) measurements using an iXeed CF analyzer, repeating this process for mature seeds to compare maturity levels across ecotypes. We will then test the germination capacity of immature and mature seeds following standard 28-day germination tests at 25° or 29/19°C with a 12-hr photoperiod. We will replicate germination conditions within four incubators. We will examine viability of remaining non-germinated seeds via a tetrazolium staining assay. We will use a separate sample of seeds (4 sub-samples of 25 seeds each) to calculate changes in seed moisture content on a dry mass basis and dry matter accumulation between immature and mature seeds via the oven-dry method (103°C, 24 hr).We will focus on the desiccation tolerance of mature seeds since this represents the target developmental level for restoration practitioners. For each ecotype, we will equilibrate seeds over saturated LiCl solutions and replicate drying treatments four times. We will monitor changes in fresh mass daily using a sample of 10 seeds. We will then remove seeds from desiccators upon equilibration and re-hydrated 100 seeds on damp germination blotter for 1 h. Seeds will then be transferred to new dishes containing germination blotters moistened with 5 mL of distilled, deionized water and monitored for germination as described above.We will use controlled deterioration tests to compare seed aging stress tolerance between ecotypes.For each ecotype, we will subject mature seeds (n=1000) to a rehydration treatment (47% RH, 20°C, 14 d) followed by an aging treatment (60% RH, 45°C). Each treatment will be replicated at least two times (n=500 seeds per replicate). One sample of 50 seeds from each replicate will be withdrawn from the ageing treatment after 1, 2, 5, 9, 20, 30, 50, 75, 100, and 125 days then subjected to a standard germination test as described previously. Resultant seed survival curves will generate a relative vigor index for each ecotype.We will use non- and semi-parametric statistical analyses to compare seed quality and germination data from initial tests and seed desiccation studies between wiregrass ecotypes. Seed survival curves resulting from controlled deterioration tests for each ecotype will be analyzed using Probit regression.

Progress 05/01/24 to 04/30/25

Outputs
Target Audience:Our target audiences during the project period included researchers, public land managers from state and federal organizations, restoration practitioners, private landowners, and undergraduate and graduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Over the last year, our laboratory technician and three undergraduates worked with Drs. Crandall, Fill, and Baruzzi to revise a peer-reviewed publication written the previous year. All of our mentees are seeking graduate positions, so we intended the training to prepare them for the rigors of graduate school and provide them with experience in publishing. The paper resulting from these efforts is currently accepted for publication by Ecological Solutions and Evidence. How have the results been disseminated to communities of interest?We have disseminated our results to our target audiences using a variety of venues. To date, we have published eight peer-reviewed papers, with an additional five papers in preparation. For all publications, we have archived our data to ensure it is available for future syntheses. In addition, we have presented our results at four professional conferences, including four oral presentations and one poster. In Septemner 2024, Drs. Fill & Crandall presented work on wiregrass at the International Association for Vegetation Science in Portugal. Dr. Fill also presented an invited seminar at Marshall University. Dr. Crandall concentrated heavily on presenting to fire practitioners during the last year, which included presentations to the Florida Wildflower Association and two presentations to the North Florida Prescribed Burn Council. Additionally, in April 2025, Drs. Crandall and Baruzzi will be presenting at the Florida Native Plant Society conference, which attracts participants from both research and applied backgrounds. We are currently preparing a series of six University of Florida extension documents, including the results of this research. These will be openly available to the public online through the Electronic Data Information Source. What do you plan to do during the next reporting period to accomplish the goals?During the next 6 months, we will be actively submitting and revising manuscripts and outreach materials. We expect to publish four manuscripts resulting from work completed for Objectives 1 and 3 in peer-reviewed publications, one of which is already in review. In addition, we expect to publish a fifth manuscript that synthesizes our results from this project and our previous research (which was funded by USDA NIFA). Specifically, we intend to publish research on the influence of ecotypic, climatic, and management variables on 1) seed quality, 2) germination performance, and 3) seed storage, as well as 4) the effects of seeding rate on wiregrass performance, and 5) a synthesis of our research on wiregrass ecology.

Impacts
What was accomplished under these goals? Objective 1: We successfully published a paper on the effects of competition on wiregrass growth and establishment. We are currently preparing a paper examining how seeding rates affect the establishment, growth, and survival of different wiregrass ecotypes. We expect to submit this paper in early April 2025. Objective 2: After several rounds of revisions, our manuscript detailing the effects of fungi on wiregrass growth has been accepted for publication by Ecological Solutions and Evidence. We are currently revising a synthesis paper on the ecology of wiregrass based on our results from Objectives 1 and 2, as well as some of our previous USDA NIFA-funded research on wiregrass. Objective 3: We finished testing the morphology, proportion of filled seeds, viability, germination capacity, desiccation tolerance, and aging stress tolerance of seeds collected from mesic and xeric sites in 2021 and 2022. We have prepared three manuscripts. One is currently under review, and the remainder will be submitted in the next couple of months

Publications

  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Love, D.T., J.M. Fill, A. Zee, S. Tevlin, H.E. P�rez, and R.M. Crandall. 2024. Competition limits first-year growth and flowering of wiregrass (Aristida beyrichiana) at a sandhills restoration site. PLOS One 19(9): e0297795.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Baruzzi, C.&, A. Kimball, D. Love, V. Lopez-Scarim, A. Zee, R.M. Crandall, E. Karlsen-Ayala, A. Al-Agely, and J.M. Fill. 2025. Effects of soil amendments on wiregrass biomass production. Florida Native Plant Society Conference, Gainesville, FL. April 2-6.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Fill, J.M., I. Meadows, J.L. Walker, R.M. Crandall, and J.L. Kerrigan. 2024. Smut fungus (Langdonia walkerae) incidence is lower in two bunchgrass species (Aristida stricta and A. beyrichiana) after fires early in the year. American Journal of Botany, DOI: 10.1002/ajb2.16286.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Fill, J.M., and R.M. Crandall. 2024. High survival promotes bunchgrass persistence in old-growth savannas. Ecosphere 15(12): e70092
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Carney, T., D. Adams, A Susaeta, S. Goewey*, and R.M. Crandall. 2024. The informal economy of wiregrass production for longleaf pine restoration. Trees, Forests & People, DOI: 10.1016/j.tfp.2024.100620.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2025 Citation: Kimball, A., D. Love, V. Lopez-Scarim, A. Zee, J.M. Fill, E.M. Karlsen-Ayala, C. Baruzzi, R.M. Crandall. 2025. Mycorrhizal fungi affect growth of an endemic bunchgrass in pine savannas. Ecological Solutions and Evidence, DOI: 10.1002/2688-8319.70026.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Love, D.T., J.M. Fill, A. Zee, S. Tevlin, H.E. P�rez, and R.M. Crandall. 2024. Competition limits first-year growth and flowering of wiregrass (Aristida beyrichiana) at a sandhills restoration site. PLOS One, DOI: 10.1371/journal.pone.0297795.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Carney, T., R.J. Williams, T. Kapellusch, R.M. Crandall, A. Susaeta, D.C. Adams. 2024. Fanning the flames of cooperation: A collective action approach to prescribed fire agreements. 2024 XXVI International Union of Forest Research Organizations World Congress, Stockholm, Sweden, June 23-29.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Crandall, R.M., and J.M. Fill. 2025. Exploring Floridas old-growth savannas& under your feet! Florida Native Plant Society Conference, 2025 Gainesville, FL, April 2-6. (Referred seminar)
  • Type: Websites Status: Published Year Published: 2025 Citation: Crandall, R.M., and J.M. Fill. 2021-present. Wiregrass Blog is a resource for restoration practitioners to read about recently published research, learn about collecting and planting wiregrass, ask questions, and share their successes and failures. Since the Crandall Fire Ecology Lab started the blog on October 15, 2021, it has received at least 200 reads each month and consistently has 6-8 visits daily. https://www.ecologyonfire.com/wiregrass-blog
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Crandall, R.M., J.M. Fill, E. Bridges, and S.L. Orzell. 2024. Bunchgrasses are stable in frequently burned old-growth savannas. Botany 2024, Grand Rapids, MI, June 15-19.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Fill, J.M., D. Love, A. Zee, S. Tevling, H. Perez, and R.M. Crandall. 2024. Identifying important considerations for successful bunchgrass restoration from seed. National Conference for Ecological Restoration, Albuquerque, NM, April 14-19.
  • Type: Other Status: Published Year Published: 2024 Citation: Fill, J.M. 2024. Old-growth grasslands in 3D: Species, communities, ecosystems. Marshall University. October 26. Huntington, WV. (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M., C. Kinslow, and J.M. Fill. 2024. Wiregrass Restoration and Research Panel Discussion, Virtual, March 1. (Invited panel)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M., C. Kinslow, and J.M. Fill. 2024. Advanced Wiregrass Restoration and Management. Southern Fire Exchange. Wiregrass Restoration and Research Panel Webinar, Virtual, January 24. (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M. 2024. Tales of plants that thrive where fire and water collide. Florida Wildflower Foundation, November 20. Recording available at: https://www.youtube.com/watch?v=3ILcLyP7axQ (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M. 2024. Wandering through wiregrass. Hogtown Creek Nature Talk, Gainesville, FL, April 7. (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M. 2024. Keep on burnin: What research tells us about prescribed fires and wildfires. Institute for Learning in Retirement, Oak Hammock. March 28. (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M. 2024. Wandering through wiregrass. Frog Drinks at First Magnitude Brewing Company, Gainesville, FL, January 4. (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M. 2024. Understanding fire behavior using matchstick forests. GATORWISE, Gainesville, FL, March 23. (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M. 2024. Understanding fire. 2024. UF Student Association for Fire Ecology, Gainesville, FL, October 25. (Invited seminar)
  • Type: Other Status: Published Year Published: 2024 Citation: Crandall, R.M. 2024. Fire regimes in old-growth grasslands. 2024. North Florida Prescribed Burn Association Biannual Meeting, October 22. (Invited seminar)
  • Type: Other Status: Other Year Published: 2024 Citation: Fill, J.M., M. Muschamp, C. Baruzzi, F. Tricone, R. Anderson, and R. M. Crandall. 2024. For plants under fire, its all about survival. International Association for Vegetation Science Annual Meeting, Funchal, Portugal. September 16-20. (poster)


Progress 05/01/23 to 04/30/24

Outputs
Target Audience:Our target audiences during the project period included researchers, public land managers from state and federal organizations, restoration practitioners, private landowners, and undergraduate and graduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?We recieved a grant during the summer of 2023 from the University of Florida Institute of Food and Agricultural Sciences to support an undergraduate intern: Crandall, R.M. (PI). 2023-2024. Determining the effects of wiregrass sowing rate on establishment. College of Agriculture and Life Sciences Florida Agricultural Experiment Station, $3,700. With the guidance of Drs. Crandall and Fill, the undergraduate student led the writing of a manuscript on the effects of competition on wiregrass establishment and growth. The paper is currently in press at Plos One. Drs. Crandall and Fill used preliminary results for a new grant: Lui, T. (PI), R.M. Crandall (co-PI), and J.M. Fill (co-PI). 2023-2024. Combining ecological and evolutionary perspectives to understand grass-fire relationships across scales. UF Institute of Food and Agricultural Sciences Forest Jumpstart Award, $49,484.40. The objective of this grant is to determine how wiregrass grows, including examining the bud dynamics and morphology. Over the last year, our laboratory technician and three undergraduates worked with Drs. Crandall, Fill, and Baruzzi to write a peer-reviewed publication. We led the students through each step of the writing process and assigned sections for each student to write and revise. All of our mentees are seeking graduate positions, so we intended the training to prepare them for the rigors of graduate school and provide them with experience publishing. The paper resulting from these efforts is currently submitted for review at Forest Ecology and Management. Dr. Fill completed an online course in Bayesian Data Analysis in R, February 12-16, 2024. www.physalia-courses.org This educational opportunity has been beneficial as we analyze the seeding rate data from Objective 1. One M.S. student completed research on Objective 3 and successfully defended her thesis in late July 2023. We also trained multiple undergraduate research associates who received training in seed biology techniques, seed testing equipment, and field monitoring techniques. The M.S. student gained valuable field research experience and training in advanced statistical techniques. She also developed non-technical skills by mentoring the undergraduate research associate in laboratory techniques. The M.S. student is now employed by the U.S. Army Corp of Engineers, supporting their habitat restoration efforts. The undergraduate students are pursuing graduate positions or employment in natural areas management, including as a habitat restoration specialist with the National Park Service How have the results been disseminated to communities of interest?Drs. Crandall and Perez led a "Wiregrass restoration Workshop" to inform local land managers about the science behind restoration and teach them how to test for seed viability. Lochloosa Wildlife Management Area, St. Johns River Water Management District, October 10, 2023. Drs. Crandall and Fill gave a webinar for Southern Fire Exchange on January 24, 2024. There were approximately 300 participants watching the webinar live, and hundreds more have watched the recording posted on YouTube. https://www.youtube.com/watch?v=9khPiD5g9pM&t=4s The webinar was followed by a panel discussion where researchers and restoration professionals could ask questions and share their experiences restoring areas with wiregrass. The panel discussion was not recorded, so participants would be encouraged to openly share and ask questions. We disseminated our results via multiple oral and poster presentations. One talk occurred in January 2023 in Cali, Colombia at the Centro Internacional de Agricultura Tropical (CIAT) to an audience of about 30 participants. Here we described current research efforts on wiregrass seed biology and implications for habitat restoration. During May 2023, we detailed environmental factors that influence wiregrass seed quality to a delegation of five international collaborators from the Corporación Autónoma de la Valle Del Cauca (Cali, Colombia) visiting the UF campus during May 2023. Two undergraduate students who have been integral to data collection presented posters at the University of Florida Undergraduate research forum in November 2023, and our M.S. student presented a poster at the 14th Biennial International Society for Seed Science Conference (Paris, France; July 3-7, 2023) detailing environmental factors that drive wiregrass seed quality. Over the last year, several invited talks were disseminated to land managers local to Gainesville, Florida as the opportunity arose. Last (but not least), our M.S. student completed her thesis presentation discussing all aspects of Objective 3 results to an audience of about 25 in late July 2023. What do you plan to do during the next reporting period to accomplish the goals?We expect to publish 3-6 manuscripts in peer-reviewed publications and develop a series of extension documents to be published with the University of Florida Electronic Data Information Source (EDIS). We will also disseminate our findings at 2-3 conferences and deliver outreach presentations as opportunities arise.

Impacts
What was accomplished under these goals? Objective 1: We discontinued weeding treatments in our competitor removal plots in May 2023 and began the manuscript submission process, including data analyses, writing, and editing. We submitted our first manuscript about competition effects on wiregrass growth and flowering to Plos One, received favorable reviews, and are awaiting the notice of final acceptance. The field was burned with prescribed fire in July 2023. In fall 2023, we mapped and measured all wiregrass seedlings and collected community composition once again. We also collected seeds from flowering plants for germination testing. We are preparing to analyze and prepare our second paper on how seeding rates affect wiregrass establishment, growth, and flowering. We completed the field camera data collection in January 2024 and archived photographs for analyses of community change over time. Objective 2: We completed our greenhouse inoculation experiment, including biomass harvest, spore counts, and mycorrhizal inoculum potential testing. We completed data analyses and are currently preparing the manuscript for publication. Objective 3: We completed testing the morphology, proportion of filled seeds, viability, germination capacity, desiccation tolerance, and aging stress tolerance of seeds collected from mesic and xeric sites in 2021 and 2022. We analyzed the data using key factors including ecotype (i.e., mesic vs. xeric), burn month, seasonal temperatures, storage time, and equilibrium relative humidity as predictors for seed responses. We found that ecotype and burn timing strongly impact seed lot quality but cannot fully account for inter-population variability. In contrast, seed lot age and seasonal germination temperature had the strongest impacts on germination performance, with winter-appropriate temperatures significantly increasing the time to germination. Both desiccation and aging stress tolerance were likewise largely unaffected by ecotype or burn timing, although some inter-population variability did exist. Further research into the storage behavior of A. beyrichiana seeds is necessary. However, our results suggest that seeds are desiccation tolerant but may be short-lived. We are currently preparing manuscripts based on these results for submission to peer-reviewed journals.

Publications

  • Type: Journal Articles Status: Published Year Published: 2024 Citation: Fill, J.M., I. Meadows, J.L. Walker, R.M. Crandall, and J.L. Kerrigan. 2024. Smut fungus (Langdonia walkerae) incidence is lower in two bunchgrass species (Aristida stricta and A. beyrichiana) after fires early in the year. American Journal of Botany, DOI: 10.1002/ajb2.16286.
  • Type: Journal Articles Status: Submitted Year Published: 2024 Citation: Kimball, A., D. Love, V. Lopez-Scarim, A. Zee, J.M. Fill, E.M. Karlsen-Ayala, C. Baruzzi, R.M. Crandall. Mycorrhizal fungal spore availability affects growth of an endemic bunchgrass in pine savannas. Forest Ecology and Management, in review.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2024 Citation: Love, D.T., J.M. Fill, A. Zee, S. Tevlin, H.E. P�rez, and R.M. Crandall. 2024. Competition limits first-year growth and flowering of wiregrass (Aristida beyrichiana) at a sandhills restoration site. PLOS One, in press.
  • Type: Theses/Dissertations Status: Published Year Published: 2023 Citation: Tevlin. S. 2023. Untangling seed quality, germination, and stress tolerance in Aristida beyrichiana to improve the efficacy of resource use in seed-based restoration. M.S. Thesis, University of Florida, Gainesville, Florida.


Progress 05/01/22 to 04/30/23

Outputs
Target Audience:During the 2022-2023 project year, we reached a variety of audiences. Undergraduate and graduate students learned about our wiregrass research by directly participating in the research or by attending a guest lecture or field tours. Restoration practitioners attended many of the presentations we delivered at regional meetings, and they continue to interact with us during field tours and on our wiregrass blog. Several of our presentations were recorded and are now available on YouTube. In the next year, we will begin publishing peer-reviewed publications from this work to target an academic audience as we continue to disseminate our preliminary results to those who will benefit most from the knowledge- restoration practitioners. Changes/Problems:Objective 3 proposes to examine the role of mycorrhizal fungi and water in the establishment and growth of wiregrass. We have had to revise the methods to meet this objective, given we could not test it in the field (see 2022 annual report for more details) and growing our own inoculum failed (see more details under what was accomplished). We are still confident we can answer our original question by testing the effects of degraded, pristine, and inoculated soil. Furthermore, the degraded soil has been inoculated with both pristine soil and a commercial inoculum (4 treatments total replicated 36 times). The experiment is already in progress in a growth chamber. Preliminary results indicate that wiregrass establishment and growth are greatest in pristine soil and lowest in degraded soil. These data should have implications for management because they will tell us whether mycorrhizae are necessary for wiregrass establishment and growth during early restoration, in addition to indicating the best way to amend soil. More wiregrass restoration sites have degraded soil that has been tilled and sprayed with herbicide multiple times, likely affecting the presence of mycorrhizal fungi. Given we have amended this objective and expanded the testing we will do on the wiregrass plants, we applied for and were granted additional funds: $2,000 from the Florida Native Plant Society to test mycorrhizae colonization of roots and $3,700 from a University of Florida internal grant to support an undergraduate student who will measure above- and belowground wiregrass traits. What opportunities for training and professional development has the project provided?This project has provided considerable mentoring opportunities for the more than eight undergraduate and graduate students and two postdocs involved in this project. Students have been instrumental in collecting data and maintaining plots, such as weeding, counting and measuring wiregrass seedlings, and surveying community composition. Two undergraduate students will be using the results from the field and their growth chamber experiment for their senior thesis. Another undergraduate is doing a project using the mapped soil data in ArcGIS. All undergraduate students, field technicians, and postdocs participate in lab meetings where we discuss the data collected, make observations, and share our individual goals and interests. In addition, we have trained one M.S. and one undergraduate student on the seed biology and germination ecology of wiregrass. These students have also been trained to use seed quality testing equipment and perform seed quality analyses. The M.S. student gained valuable field research experience and training in advanced statistical techniques. The M.S. student has developed a network of restoration practitioners throughout the region, which she is leveraging to identify post-graduation opportunities. The M.S. student also developed outstanding written and oral communication skills as part of manuscript preparation and development of presentations for local and international audiences. During the 2021-2022 project year, all project members participated in various levels of training offered online and through the University of Florida, such as R and Python Programming and GitHub usage. PI-Dr. Crandall and co-PI Perez lead weekly discussions for their individual lab groups on topics related to statistical modeling, writing, and professional development. We read and discuss peer-reviewed papers, complete exercises, and work as a team to reach conclusions. These training sessions are meant to teach undergraduate and graduate students and postdoctoral associates in our respective labs at the University of Florida skills that should benefit their careers in the future. In addition, the Crandall and Perez Lab groups are in regular communication and meet once a month to discuss the project and provide guidance. How have the results been disseminated to communities of interest?We continue to update our progress in the wiregrass blog we started in the fall of 2021. This is also a place where stakeholders can share their lessons learned and ask questions. Since its inception, it has received at least 200 reads each month and consistently has 6-8 visits daily. See https://www.ecologyonfire.com/wiregrass-blog. In December 2022, PI-Crandall included some of our findings in an online seminar attended by over 200 stakeholders. The same month, she presented some preliminary results to fire practitioners at the Central Florida Prescribed Fire Council, attended by nearly 300 participants both virtually and in person. Additionally, co-PI Perez and the M.S. student participated in a groundcover restoration and enhancement workshop, where the M.S. student presented results pertaining to population-based differences in wiregrass seed quality. This activity reached over 50 native plant producers, restoration practitioners, and local, state, and federal employees. Finally, PI-Crandall delivered a guest lecture and led a field tour of the wiregrass restoration field for three University of Florida classes:Ecological Restoration (~20 students), Fire Ecology and Management (~24 students), and Foundations in Natural Resources and Conservation (~45 students). What do you plan to do during the next reporting period to accomplish the goals?Objective 1: During the 2023-2024 project year, we will sample our wiregrass plots again for survival, growth, and reproduction. We will continue to remove plants from the competitor removal plots. Additionally, we anticipate that undergraduate students who have begun independent projects in the wiregrass restoration field will start writing and developing manuscripts as applicable. Objective 2: During the 2023-2024 project year, we will finish the growth chamber experiment and examine how restoration soil amendment with undisturbed soil or commercial inoculum affects the growth of wiregrass seedlings. Students will begin analyzing data and writing manuscripts. This project was supplemented this year by a University of Florida internal grant that provides a summer salary ($3,700 total) for an undergraduate student to gain an authentic research experience. This student will lead at least one publication. Objective 3: During the 2023-2024 project year, we expect to complete the aging stress tolerance experiment and data analysis. We will graduate one M.S. student (August 2023) who will have synthesized all data and reported results into a comprehensive thesis. We will present a portion of this work at the 14th Biennial International Society for Seed Science Conference (Paris, France; July 3-7, 2023). We also estimate submission of 1-3 manuscripts to peer-reviewed publications resulting from work completed for Objective 3.

Impacts
What was accomplished under these goals? Objective 1: We continued weeding our competitor removal plots during the 2022-2023 project year. In the fall of 2022, we mapped and measured the wiregrass seedlings and collected initial community composition in all the plots. We also installed two field cameras that take at least several pictures daily to monitor community phenology and development over time. Despite not being burned, some small wiregrass plants flowered. We collected some seeds from these plants and are currently testing them for germination. Objective 2: We originally proposed to test the role of mycorrhizae in wiregrass establishment in the field. We did not feel confident that there was a sufficient area of soils mapped as wet to conduct a rigorous field experiment in our wiregrass restoration field. Thus, we decided to answer the same question using a controlled experiment in a growth chamber. During the 2022-2023 project year, we attempted to grow mycorrhizal inoculum from soil collected at an undisturbed (i.e., pristine) site, but time constraints and contamination prevented us from successfully growing a sufficient amount. In January 2022, we collected soil from undisturbed and disturbed sites and purchased a small amount of commercial MycoApply inoculum for a growth chamber experiment. We modified the research objective to target another equally important question for restoration practitioners: In what planting situations does wiregrass benefit the most from mycorrhizae? We planted wiregrass seeds from a xeric site into the undisturbed soil, disturbed soil, disturbed soil amended with undisturbed soil, and disturbed soil mixed with commercial inoculum. The seeds have germinated, and wiregrass plants are currently growing. In the next month or two, we will harvest the seedlings, measure their biomass, and quantify mycorrhizal colonization via spore counts and root colonization. Samples of the undisturbed and disturbed soil were submitted for nutrient testing. The cost of testing for spore counts and root colonization was beyond our budget, so we applied for and were granted supplemental funds ($2,000) from the Florida Native Plant Society to complete this experiment. Objective 3: We finished testing the morphology, proportion of filled seeds, viability, germination capacity, and desiccation tolerance of seeds collected from mesic and xeric sites in 2021 and 2022. We have nearly completed the aging stress tolerance experiments (completion expected May 2023). We have analyzed most data using key factors, including ecotype (i.e., mesic vs. xeric), burn month, seasonal temperatures, storage time, and equilibrium relative humidity as predictors for seed responses. We estimate that 85% of the work for Objective 3 has been completed.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Tevlin, S. and Adams, C.R. 2023. "Population-based differences in Aristida stricta seed quality." In Seed Source Range in Restoration Research at UF: Linking plant sourcing approaches to restoration goals. Groundcover Restoration and Enhancement Workshop. Gainesville, FL (Invited seminar)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Crandall, R.M. 2022. Bunchgrass ecology in frequently burned southeastern pine savannas. Horticulture Sciences Department Seminar Series, University of Florida Gainesville, FL, October 10. (Invited seminar)


Progress 05/01/21 to 04/30/22

Outputs
Target Audience:Our target audiences during 2021-2022 project year have included researchers/scientists, public land managers from state and federal organizations, private landowners, and graduate and undergraduate students. Changes/Problems:When we were developing our proposal, which was just as COVID had begun, we got some soft quotes for the cost of restoring 12 hectares to wiregrass. To remove trees, herbicide, and plant to wiregrass seeds, we were quoted approximately $20,000. Post-COVID when the award was made, our quotes for the same work were over $120,000. We reached out to University of Florida alumni and friends in the areaand were able to restore 6 hectares with the funding that was awarded by the USDA. We have not sacrificed the integrity of the project and are still able to complete our experiment with extra room for additional undergraduate experiments, but the area we are studying is significantly smaller than what we originally proposed. Additionally, we had proposed to identify whether the presence and abundance of endomycorrhizal fungi or the availability of water limit wiregrass ecotype performance in the field, but after consulting with a microbial ecologist, we have decided to test this objective in the greenhouse first. The justification is so we can have greater control over the soil organisms and concludedefinitively which soil components are affecting growth of wiregrass ecotypes in different soil. In other words, we are conducting a more controlled experiment than we couldin the field.We will develop inoculantsthat independently contain microbes and fungi to test each separately and follow the 8-week greenhouse experiments during the Summer of 2022 with field experiments (as written in our proposal) during the Fallof 2022. What opportunities for training and professional development has the project provided?This project has provided mentoring opportunities for several undergraduate and graduate students, and postdocs involved in this project. Students have been instrumental in seed collection and field preparation. They have been involved in experimental design and soil mapping, learning about soil horizons and depth to water table. During the 2021-2022 project year, all project members took mental health training and most participated in various levels of training offered online and through the University of Florida, such as R and Python Programming and GitHub usage. PI-Dr. Crandall and co-PI Perez lead weekly discussions for their lab group on topics related to statistical modelling, writing, and professional development. We read and discuss peer-reviewed papers, complete exercises, and work as a team to reach conclusions. These training sessions are meant to teach the undergraduate and graduate students and postdoctoral associates in our respective labs at the University of Florida skills that should benefit their careers in the future. In addition, the Crandall and Perez Lab groups meet once a month to discuss the project and provide guidance. How have the results been disseminated to communities of interest?Although we do not currently have results from this study, we have learned a tremendous amount while preparing a degraded pine savanna for restoration. Upon request from a stakeholder, we have started a wiregrass blog where we are sharing what we have learned, including our failures and successes. This is also a place where stakeholders can share their lessons learned and ask questions.Since the Crandall Fire Ecology Lab started the blog on October 15, 2021, it has received at least 200 reads each month and consistently has 6-8 visits daily. See https://www.ecologyonfire.com/wiregrass-blog What do you plan to do during the next reporting period to accomplish the goals?Objective 1:During the 2022-2023 project year, we will begin sampling our wiregrass plots for establishment, growth, and survival. We will continue to remove plants from the competitor removal plots. Additionally, we anticipate that undergraduate students will begin independent projects within our experimental framework to examine additional questions such as nutrient addition (e.g., addition of fly ash from our local biomass plant). Objective 2: During the 2022-2023 project year, we will identify the relative roles of microbes and fungi for the establishment and growth of wiregrass ecotypes in different soil types. This experiment will be first completed in the greenhouse where we are able to more closely control each factor. During May 2022, we will collect soil samples from established wiregrass sites to develop inoculants that contain either microbes or fungi and test these using the xeric and mesic soil and xeric and mesic seeds from our field experiment. See Changes/Problems. We anticipate we will begin testing the effects of fungi in the field experiment during late summer/early fall of 2022. Objective 3: During the 2022-2023 project year, we will conduct experiments to examine desiccation and aging stress tolerance of wiregrass seeds from mesic and xeric sites. In addition, we will also test the viability of seeds that have been in cold storage for 1-5 years at the USDA Forest Service National Seed Laboratory in Georgia.

Impacts
What was accomplished under these goals? Objective 1:During the 2021-2022 project year, the overcame barriers to restoring pine savannas with wiregrass understories. See Changes/Problems. We successfully prepared 6 hectares of degraded pine savanna for planning by removing trees, root raking, herbiciding, and plowing. The field was meticulously mapped for xeric and mesic soil types and in November/December 2021, wiregrass seeds were collected from mesic and xeric sites. The field was planted during February/March 2022 according to our experimental design and individual plots were installed to examine wiregrass ecotype success. On April 1, 2022 (no joke), we saw the first wiregrass individuals in our plots, and there are now as many as 20 plants in each plot. We have just completed the first weeding of our competitor removal plots. Objective 2: During the 2021-2022 project year, we were just beginning the experiment and restoring the site. Thus, we have not yet begun to identify whether the presence and abundance of endomycorrhizal fungi or the availability of water limit wiregrass ecotype success. Objective 3: During November/December 2021, wiregrass seeds were collected from mesic and xeric sites. We have begun to test morphology, proportion of filled seeds, and viability prior to examining desiccation and aging stress tolerance.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Crandall, R.M. 2022. Tales of plants that thrive where fire and water collide. Department of Biology, University of North Carolina, Greensboro, NC, February 16 (Invited Seminar)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Crandall, R.M. 2022. Tales of plants that thrive where fire and water collide. School of Natural Resources and Environment (SNRE) Seminar Series, University of Florida Gainesville, FL, February 21. (Invited Seminar)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Fill, J.M., C. Baruzzi, and R.M. Crandall. 2021. An update on fire ecology of southern pine ecosystems. Society of American Foresters and School of Forest, Fisheries, and Geomatics Sciences Fall Symposium: Southern Pine Update, October 12-13, Gainesville, FL.
  • Type: Other Status: Published Year Published: 2021 Citation: Fill, J.M., C. Baruzzi, and R.M. Crandall. 2021. Led Field Trip: Upland pine ecosystem restoration trip to Lochloosa Wildlife Management Area. Society of American Foresters and School of Forest, Fisheries, and Geomatics Sciences Fall Symposium: Southern Pine Update, October 12-13, Gainesville, FL.