The Nature Conservancy in Ohio - Ohio's Invasive Plant Range Report

Ohio's Invasive Plant Range Report

Non-native plants are plants that have been introduced, either accidentally or deliberately, into a region where they historically did not occur. Because these plants are introduced into an environment which may lack the predators or diseases which limit their populations in their native habitat, some species can become invasive and out-compete native plants. Invasive species form self-sustaining and expanding populations within a natural plant community with which they had not been previously associated (Vitousek et al., 1995).

Over 500 non-native species are naturalized in Ohio (Cooperrider et al., 2001), of these about 100 invade natural areas. The degree to which invasive plant species affect Ohio natural areas varies, but some of these plants pose serious threats to native species and the ecological integrity of Ohio’s native biological diversity. Invasive species are usually characterized by fast growth rates, prolific fruit production, rapid vegetative spread, and efficient seed dispersal and germination. They are frequently difficult or expensive to control in high-quality natural areas. They can stress native plant communities by displacing or hybridizing with native species, changing the physical structure or composition of the community, or altering important ecosystem processes such as rates of sedimentation, natural fire regimes, or soil chemistry. If left uncontrolled, the worst invaders can permanently disrupt the natural ecosystems that native plants and animals depend on to survive.

This report contains Ohio county maps showing the current documented distribution of 65 invasive plant species. The species chosen are from the list, "Ohio’s Invasive Plant Species," compiled by the Ohio Department of Natural Resources and The Nature Conservancy in consultation with botanists, horticultural professionals, and land managers throughout the state (Ohio Division of Natural Areas and Preserves, 2000.) A better understanding of their extent in Ohio is necessary for invasive plant education, control, and prevention efforts.

REPORT DESIGN

The county maps are grouped into three categories: targeted species, well-established species and watch-list (Ohio Division of Natural Areas and Preserves, 2000). The targeted species are widespread in Ohio, the most invasive in natural areas, and the most difficult to control. The well-established species are found either throughout the state or are regionally invasive. These species are considered a moderate to serious threat in natural areas. The watch-list is a group of invasive species that are currently known only from a few counties, but are very invasive in natural areas in neighboring states. Species within each group are in alphabetical order by scientific name. Species nomenclature follows Gleason and Cronquist (1991).

The maps show general distributions of species within the state. Counties colored in yellow have at least one specimen from that county in a herbarium. Density and frequency of a species within each county are not confirmed, nor are distribution trends revealed in this report. This information has not been compiled to date, but is needed to better assess the invasive problem in natural areas. It is likely that the non-native invasive species may be under-represented in the literature and herbaria.

DATA SOURCES

Distribution data was collected from the following literature sources: Andreas (1989), Braun (1961, 1967), Cooperrider (1995), Cusick and Silberhorn (1978), Fisher (1998), and Furlow (1992). Additional records were collected for species with significant data gaps in the literature by examining specimens at the following herbaria: Cleveland Museum of Natural History, Kent State University, Miami University, The Ohio State University, and Youngstown State University. A few Adams County records are located in the Cincinnati Museum Center’s Edge of Appalachia Reference Herbarium located on the Edge of Appalachia Preserve in Adams County, Ohio. Ohio Division of Natural Areas and Preserves Chief Botanist Allison Cusick provided unpublished distribution maps for several species from his research.

FURTHER RESEARCH

Much more work is needed to document and analyze the extent and severity of impacts by invasive plant species to Ohio’s natural areas. This report is a preliminary step in documenting the presence of invasive species at a regional scale. A thorough assessment of the scope and severity of invasions must incorporate data on spatial distribution, abundance, range of habitats invaded, and patterns or pathways of invasion across Ohio’s remaining natural landscape.

LITERATURE CITED

Andreas, B.K. 1989. The Vascular Flora of the Glaciated Allegheny Plateau Region of Ohio. Ohio Biological Survey Bulletin. New Series Vol. 8 No. 1. viii + 191 p.

Braun, E.L. 1961. The Woody Plants of Ohio. Ohio State University Press, Columbus, OH. 362 pp.; reprinted 1989.

Braun, E.L. 1967. The Monocotyledoneae [of Ohio]. Cattails to Orchids. With the Graminaeae by C.G. Weishaupt. Ohio State University Press. Columbus, OH. ix + 464 p.

Cooperrider, T.S. 1995. The Dicotyledoneae of Ohio. Part 2. Linaceae through Campanulaceae. Ohio State University Press, Columbus, OH. xxi + 655 p.

Cooperrrider, T.S., A.W. Cusick and J.T. Kartesz (eds.). 2001. Seventh Catalog of the Vascular Plants of Ohio. Ohio State University Press, Columbus, OH. vii + 195 p.

Cusick, A.W. and G. Silberhorn. 1977. The Vascular Plants of Unglaciated Ohio. Ohio Biological Survey Bulletin. New Series Vol. 5 No. 4. x + 153 p.

Fisher, T.R. 1988. The Dicotyledonaea of Ohio. Part 3. Asteraceae. Ohio State University Press, Columbus, OH. x + 280 p.

Furlow, J.J. 1992. The vascular flora of Ohio. Vol. 2. Part 1. The Dicotyledonaea of Ohio. Part 1. Sauraceae through Fabaceae. Checklist and Distribution Maps. Processed and distributed by the author. 107 p.

Gleason H.A. and A. Cronquist. 1991. Manual of vascular plants of northeastern United States and adjacent Canada, 2nd ed. Bronx: New York Botanical Garden. 910 p.

Ohio Division of Natural Areas and Preserves and The Nature Conservancy. April 2000. Ohio’s Invasive Plant Species. Ohio Department of Natural Resources. Columbus, OH. 2 p.

Vitousek, P., L. Loupe, C. D’Antonio and S.J. Hassol. 1995. Biological invasions as global change. pp. 213-336 in: S.J. Hassol and J. Katzenberger (eds). Elements of change 1994. Aspen Global Change Institute. Aspen, CO.

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