Decadal Changes in Ground-Layer Plant Communities Reflect Maple Dieback and Earthworm Invasion in National Forests in the Lake Superior Region, USA

Authors

Tara Bal, Michigan Technological UniversityFollow
Manuel Eduardo Anderson, Michigan Technological UniversityFollow
Mattison E. Brady, Michigan Technological UniversityFollow
Julia I. Burton, Michigan Technological UniversityFollow
Christopher R. Webster, Michigan Technological UniversityFollow

Document Type

Article

Publication Date

10-15-2025

Department

College of Forest Resources and Environmental Science

Abstract

Northern hardwood forests of the Lake Superior region face a series of novel disturbance pressures including canopy dieback. Previous studies have linked regional sugar-maple (Acer saccharum) canopy dieback to introduced earthworms, which may have coinciding impacts on the ground-layer plant community. Dieback–earthworm interactions may lead to important longer-term changes in forest structure and function, but these relationships but have not been characterized. We sampled ground-layer plant communities in five national forest units in Michigan, Wisconsin, and Minnesota in 2010, and again just over a decade later in 2021. Non-metric multidimensional scaling ordination and indicator species analysis were used to assess relationships among ground-layer community composition and structure, functional traits, and environmental gradients including forest-floor condition and A. saccharum canopy dieback. Increases in dieback and earthworm disturbance in the decade between inventories were accompanied by a marked divergence in observed ground-layer plant community structure between national forests. Ordinations of 2021 data indicated a strengthening relationship between forest-floor condition and earthworm abundance. Our results suggest that earthworm impacts and A. saccharum dieback are driving changes in the ground layer on broad geographic and temporal scales, with short- and long-term implications for plant-community structure and function, and higher trophic levels.

Publisher's Statement

Copyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. Publisher’s version of record: https://doi.org/10.3390/f16101583

Publication Title

Forests

Recommended Citation

Bal, T., Anderson, M. E., Brady, M. E., Burton, J., & Webster, C. R. (2025). Decadal Changes in Ground-Layer Plant Communities Reflect Maple Dieback and Earthworm Invasion in National Forests in the Lake Superior Region, USA. Forests, 16(10). http://doi.org/10.3390/f16101583
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/2065

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

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