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Project ID:

25-1-01-8

Year:

2025

Date Started:

09/30/2025

Date Completed:

Title:

Long-term effects of fire on Microstegium vimineum demography and seed bank dynamics in Central Hardwood Forests

Project Proposal Abstract:

Low-intensity surface fires historically helped maintain oak-hickory dominated systems in eastern deciduous forests. Widespread decline of oak abundance over the past two decades has spurred the reintroduction of fire to many of these landscapes, and fire is also increasingly used as a tool to manage invasive plant species. Yet, numerous studies have demonstrated that individual fires promote annual invasive grasses, which are among the most problematic invaders in eastern deciduous forests. Much less is known about how repeated burning affects invasive grass populations over the long-term. Additionally, most studies focus on seedling and adult life stages, overlooking seed bank dynamics and their responses to either individual or repeat fire. Understanding seed bank dynamics is imperative, despite their logistical challenges, because they act as a hidden legacy that can impact population dynamics and management. Given the re-establishment of prescribed fire regimes and increasing non-native plant introductions, there is an urgent need to determine the fire regime characteristics that are most effective for managing and reducing non-native invasive grasses in eastern deciduous forests. By studying how invasive grass demography varies across a fire regime gradient, encompassing individual and repeated fires over long time periods, this study seeks to improve demographic rate estimates for an annual plant projection equation to help inform targeted management. Analysis of invasive species seed banks will increase the understanding of the long-term effects of fire management on invasion dynamics and help determine the most effective fire regime for managing invasive species. Our main objective is to determine the long-term effects of fire management on the demographic life stages of an annual invasive grass, Microstegium vimineum (Trin.) Camus (Japanese stiltgrass), to improve management of this and similar annual invasive grass species. With this funding we will address this specific question: Q1) How do the germination and viability of M. vimineum seeds and the persistence of seed banks vary along a fire regime gradient? We hypothesize that increased fire activity will reduce the germination and viability of seeds M. vimineum seeds through microclimate impacts, specifically by decreasing soil moisture and increasing soil temperature.
Activities to be performed: To accomplish this objective, we will complete the following tasks: 1) perform a seed bank tray study, and 2) use data from the seed bank study and other field measurements to model the growth rates of M. vimineum populations to determine which fire regime is most effective for reducing invasive grass populations and uncover the mechanisms driving these demographic responses. Activities will include removing the second closed tray of the first-year seed bank trays, testing seed viability, and quantifying pyrogenic organic matter. We will also perform data analyses including fitting an annual plant projection equation, conducting a Life Table Response Experiment, and fitting linear mixed effects and structural equation models.
Expected deliverables: The deliverables from this research will include a comprehensive final report, a manuscript for a journal publication, and one chapter of a master’s thesis. Deliverables will be shared with field managers, researchers, forestry extension staff, and other stakeholders through webinars, presentations, and publications in peer-reviewed journals. Results will also be presented at a regional conference to ensure broad dissemination to the scientific and management communities.
Benefits: The Fraterrigo lab has worked extensively with regional fire managers for the last decade, including managers from the U.S. Forest Service and Illinois Department of Natural Resources, who have identified M. vimineum as a volatile and unpredictable fuel type that can intensify fires, posing ecological and human risk. This study will advance both

Principal Investigator:

Jennifer M. Fraterrigo

Agency/Organization:

University of Illinois-Urbana-Champaign

Branch or Dept:

Department of Natural Resources & Environmental Sciences

Other Project Collaborators

Type	Name	Agency/Organization	Branch or Dept
Agreements Contact	Paul Ellinger	University of Illinois-Urbana-Champaign	Department of Natural Resources & Environmental Sciences
Budget Contact	Paul Ellinger	University of Illinois-Urbana-Champaign	Department of Natural Resources & Environmental Sciences
Student Investigator	Kayla Morrison	University of Illinois-Urbana-Champaign	Department of Natural Resources & Environmental Sciences