POSTER PRESENTER CO-AUTHOR: Amanda Little (UW-Stout) TITLE: Black ash decline in two Western Wisconsin swamps: Changes in forest structure and hydrology ABSTRACT: The emerald ash borer (Agrilus planipennis, EAB) poses a significant threat to black ash (Fraxinus nigra) populations across the United States, leading to widespread wetland impacts. This study investigates the effects of emerald ash borer infestation on forest structure and composition over time in two Western Wisconsin ash swamps by analyzing canopy cover, size class distributions, and successional dynamics. Muddy Creek swamp (MC) is a successionally older, more diverse, peat-based system located in eastern Dunn County, while Gilbert Creek (GC) is younger, with silt loam soils, in western Dunn County. Tree inventory data were collected in 2023 and 2025 and compared across years. At GC, 29% of ash trees were alive and healthy, while 68% were diseased and 3% were dead. At MC, only 3% were healthy, 50% were diseased and 47% were dead. We suspect the higher mortality at MC is because MC was a later-successional forest with larger trees and became invaded earlier as EAB invasion spread. There was a significant decline in canopy cover across both sites from 2023 to 2025 (P < 0.001), with a larger decline at MC (P < 0.001), despite its higher tree diversity. GC exhibited roughly 25 cm higher water tables in 2024 and 2025 than in 2023. Precipitation was also about 12 cm higher in 2024 and 2025. These findings highlight the ongoing impact of EAB on forest structure and wetland ecosystems. Management practices could consider the impacts of higher water tables when planning for tree replacements in these systems. BIO: Carter is an environmental science student at UW-Stout in his senior year. He is interested in wetland conservation, especially after an internship working in stream restoration, lake monitoring, and black ash swamp research.