Profile

Microplastics and environmental pollutants · paleoecology · fire and vegetation history · sediment geochemistry · tropical, subtropical, alpine, and boreal systems

My research program examines the themes of environmental change and human-environment interaction across a range of spatial and temporal scales. Using field-based collection of sediment and water samples along with sediment cores, my group develops high-resolution environmental records through laboratory analyses of ecological and geochemical proxies. Modern research examines environmental hazards and pollutants in diverse systems, from tropical wetlands and lakes to alpine lakes and boreal peatlands, with a particular focus on microplastics, pollen, charcoal, isotopes, and elemental composition of sediments. These data are used to establish ecological baselines that support environmental management and improve predictions of future environmental change.

A central component of my work focuses on using sedimentary archives to reconstruct past environments and inform present-day conditions based on a long-term perspective. Research topics include modern environmental hazards, historical ecology including fire and vegetation histories in the tropics, paleoclimate reconstructions, and analyzing past resilience strategies to climate stress. Research projects are often in collaboration with graduate and undergraduate researchers.

Select Publications (* indicates advisee)

1. 2026Baudrix*, Juana, Erik N. Johanson, and Julie A. Buchanich*. Hydrological and sedimentary controls on microplastic distribution in an urban wetland, Spruce Bluff Preserve, Florida. Evolving Earth, 4, 100158. https://doi.org/10.1016/j.eve.2026.100158
2. 2026Horn, Sally P., Kurt A. Haberyan, Erik N. Johanson, Mauricio Murillo Herrera, Amanda Tomlinson, Chad S. Lane, Taber Friedel*, and Morgan R. Steckler. A 1500-year paleolimnological record from an ancient debris avalanche landscape in west central Costa Rica. Physical Geography, 47(3), 246–277. https://doi.org/10.1080/02723646.2026.2634482
3. 2025Garzón-Oechsle*, Andrés E., Erik N. Johanson, Sudhagar Nagarajan, and Valentina Martínez. In between the sites: understanding Late Holocene Manteño agricultural contexts in the Chongón-Colonche Mountains of coastal Ecuador through UAV-Lidar and excavation. Journal of Field Archaeology, 49(2). https://doi.org/10.1080/00934690.2024.2439223
4. 2024Swick*, Kathryn, Erik N. Johanson, and Xavier Comas. A multiproxy analysis of modern environmental change within a cypress swamp forest, Collier County, FL. Discover Environment, 2, 39. https://doi.org/10.1007/s44274-024-00065-x
5. 2024Friedel*, Taber, Erik N. Johanson, and Sally P. Horn. Post-Conquest vegetation and fire dynamics at Laguna Carse, Costa Rica: a pollen and microscopic charcoal record. Vegetation History and Archaeobotany. https://doi.org/10.1007/s00334-023-00981-7
6. 2023Garzón-Oechsle*, Andrés E., Erik N. Johanson, and Valentina Martínez. The Bola de Oro Manteños and their resilience to climate change: chronological reconstruction of agricultural modifications through age-depth modelling and carbon abundance analysis. STRATA, 1(2), 1–31. Instituto Nacional de Patrimonio Cultural, Ecuador. https://doi.org/10.5281/zenodo.10246526
7. 2023Bitting*, Madeleine, Erik N. Johanson, Kurt Haberyan, and Sally P. Horn. Response of diatom communities to climate and human disturbance: a 4200-year record from Costa Rica. The Holocene, 33(12), 1–13. https://doi.org/10.1177/09596836231197775
8. 2023Horn, Sally P., Erik N. Johanson, Mauricio Murillo-Herrera, Kurt A. Haberyan, Taber Friedel*, and Chad S. Lane. Initial limnological observations at Laguna Pozo Verde, Juan Castro Blanco National Park, Costa Rica. UNED Research Journal, 15(2), 1–6. https://doi.org/10.22458/urj.v15i2.4835
9. 2022Yanuskiewicz, Elizabeth, Chad S. Lane, Sally P. Horn, Erik N. Johanson, and Douglas W. Gamble. Compound-specific stable carbon and hydrogen isotope analyses of late-Holocene vegetation and precipitation change at Laguna Los Mangos, Costa Rica. Quaternary International, 1–11. https://doi.org/10.1016/j.quaint.2021.08.018
10. 2020Johanson, Erik N., Sally P. Horn, Chad S. Lane, Maureen Sánchez, and Jacob Cecil*. Fire history across the Little Ice Age in southern Pacific Costa Rica. Journal of Paleolimnology, 1–23. https://doi.org/10.1007/s10933-020-00118-0
11. 2019Johanson, Erik N., Sally P. Horn, and Chad S. Lane. Pre-Columbian agriculture, fire, and Spanish contact: a 4200-year record from Laguna Los Mangos, Costa Rica. The Holocene, 1–15. https://doi.org/10.1177/0959683619862032
12. 2018Horn, Sally P., Erik N. Johanson, Kurt A. Haberyan, Matthew S. Boehm, Jessie L. Johanson, Maureen Sánchez P., and Mario Hernández V. Initial limnological observations at five small lakes in southern Pacific Costa Rica. UNED Research Journal, 10(1), 119–134. https://doi.org/10.22458/urj.v10i1.2015

Teaching

Select Media Coverage

• Even Protected Florida Wetlands Can’t Escape Microplastic Pollution — FAU Newsdesk, August 2026.
• Protected Wetlands Can’t Keep Microplastics Out — Earth.com, August 2026.
• Meltdown: A More Sustainable Way Forward for South Florida — Palm Beach Illustrated, June 2024 (PDF).
• Florida Continues to Break Heat Records — WPLG Local 10, September 2021 (television interview).
• University Professors Discuss Hurricane Preparedness — FAU University Press, September 2021.

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