Ecological Classification Systems: A Definition Crosswalk for Minnesota John M. Zobel, Alan R. Ek, Tyler S. Gifford1 Background Ecological classification systems attempt to aggregate and map geographic areas based on similar physical and biological characteristics, including climate, geology, hydrology, and vegetation. Boundaries between ecoregions identify significant shifts in ecological attributes, and wildlife population dynamics often differ between each region. Classification typically follows a hierarchical scale, identifying large areas with common, broad ecological features, then dividing these regions into smaller and smaller homogeneous units based on an increasing level of detail. Terminology for state and local forest planning includes Province, Section, Subsection, Land Type Association, Land Type, and Land Type Phase, in decreasing order of size (Cleland et al. 1997; Hanson and Hargrave 1996). A growing level of environmental awareness in the late 1980s and early 1990s led to the development of several classification systems. As a component of the Minnesota Generic Environmental Impact Statement on Timber Harvesting and Forest Management (GEIS), up to nine ecoregions were proposed (at the Section level) that divided the state by predominant ecological features (Jaakko Pöyry Consulting, Inc. 1992a; Jaakko Pöyry Consulting, Inc. 1992b). Shortly after, the U.S. Forest Service refined existing schemes at the Section level (Bailey 1976; Bailey 1980; Bailey et al. 1994; McNab and Avers 1994) and began compiling independently-created subsection maps into a single collection based on the new national system of classification (Cleland et al. 1997; ECOMAP 2007). Concurrently, the Minnesota Department of Natural Resources (MNDNR) developed a classification structure in conjunction with the Forest Service, including a subsection map (MNDNR 1999) and detail at the Land Type Phase level (Hanson and Hargrave 1996). Finally, a common national classification system was released by the Forest Service for Subsections (USDA 2007), with a detailed map (Cleland et al. 2007) and subsection descriptions (McNab et al. 2007). Purpose and Results Ecological regions defined by these three classification systems often overlap. Still, many retain unique properties such as level of detail (Section versus Subsection) and/or naming convention. In addition, although the Forest Service and MNDNR methodologies are widely accepted in Minnesota, some forestry professionals and forestry applications depend on the GEIS ecoregions (e.g., Frelich et al. 2012; Zobel and Ek 2014; Zobel et al. 2021). Therefore, this research created a crosswalk between the GEIS, Forest Service, and MNDNR approaches to allow for the interchangeable use of the three systems (see Table 1). 1 John Zobel (jzobel@umn.edu), Alan Ek (aek@umn.edu), and Tyler Gifford (giffo071@umn.edu) are with the Department of Forest Resources, University of Minnesota. Research supported by the Department of Forest Resources, the Interagency Information Cooperative through the MNDNR, and the Minnesota Agricultural Experiment Station. 1 No. 312August 2021 Minnesota Forestry Research Notes Published by the Department of Forest Resources, University of Minnesota, St. Paul Table 1. Ecological classification system definition crosswalk between the GEIS, Forest Service (FS), and MNDNR approaches. Comparisons based on Jaakko Pöyry Consulting, Inc. (1992a), Cleland et al. (2007), and MNDNR (1999). GEIS Code FS Code MNDNR Code GEIS Name FS Name MNDNR Name 1 212Ma 212Ma Glacial Lake Plains Littlefork-Vermillion Uplands Littlefork-Vermillion Uplands 1 212Mb 212Mb Glacial Lake Plains Agassiz Lowlands Agassiz Lowlands 2 212La 212La Border Lakes Border Lakes Border Lakes 3 212Lb 212Lb Lake Superior Highlands North Shore Highlands North Shore Highlands 4 212Ya 212Ja Central Pine-Hardwood Forests Superior-Ashland Clay Plain Glacial Lake Superior Plain 4 212Qa 212Jd Central Pine-Hardwood Forests St. Croix Moraine St. Croix Moraine 4 212Kb 212Kb Central Pine-Hardwood Forests Mille Lacs Uplands Mille Lacs Uplands 4 212Lc 212Lc Central Pine-Hardwood Forests Laurentian Highlands Nashwauk Uplands 4 212Ld 212Ld Central Pine-Hardwood Forests Toimi Uplands Toimi Uplands 4 212Le 212Le Central Pine-Hardwood Forests Laurentian Highlands Laurentian Uplands 4 212Na 212Na Central Pine-Hardwood Forests Chippewa Plains Chippewa Plains 4 212Nb 212Nb Central Pine-Hardwood Forests St. Louis Moraines St. Louis Moraines 4 212Nc 212Nc Central Pine-Hardwood Forests Pine Moraine and Outwash Plains Pine Moraines and Outwash Plains 4 212Nd 212Nd Central Pine-Hardwood Forests Toimi Uplands Tamarack Lowlands 5 222Ma 222Ma Western Prairie/Forest Transition Zone Alexandria Moraine-Hardwood Hills Hardwood Hills 5 222Mb 222Mb Western Prairie/Forest Transition Zone Big Woods Moraines Big Woods 5 222Mc 222Mc Western Prairie/Forest Transition Zone Anoka Sand Plain Anoka Sand Plain 6 222Lc 222Lc Eastern Prairie/Forest Transition Zone Mississippi-Wisconsin River Ravines Blufflands 6 222Lf 222Lf Eastern Prairie/Forest Transition Zone Western Paleozoic Plateau Rochester Plateau 6 222Md 222Md Eastern Prairie/Forest Transition Zone Rosemont Baldwin Plains and Moraines St. Paul Baldwin Plains and Moraines 6 222Me 222Me Eastern Prairie/Forest Transition Zone Oak Savannah Till and Loess Plains Oak Savanna 6 251Be 222Me Eastern Prairie/Forest Transition Zone Southern Des Moines Lobe Oak Savanna 7 251Ba 251Ba Western Prairies Upper Minnesota River-Des Moines Lobe Minnesota River Prairie 8 251Bb 251Bb Western Corn Belt Plains Outer Coteau des Prairies Coteau Moraines 8 251Bd 251Bc Western Corn Belt Plains Northwest Iowa Plains Inner Coteau 9 222Na 223Na Red River Valley Aspen Parklands Aspen Parklands 9 251Aa 251Aa Red River Valley Lake Agassiz Plain Red River Prairie 2 Note that the geographic borders between the Forest Service and MNDNR subsections are essentially identical (with some additional naming differences). Also, although the larger GEIS ecoregions do not match groups of units in the other approaches exactly, they do show close agreement. Thus any observed deviations were considered negligible, but users of the crosswalk may want to recognize these differences. Literature Cited and References Bailey, R.G. 1976. Ecoregions of the United States (map). Presentation scale 1:7,500,000, colored. Ogden, UT: USDA Forest Service, Intermountain Region. Bailey, R.G. 1980. Description of the ecoregions of the United States. Misc. Pub. 1391. Washington, DC: USDA Forest Service. Bailey, R.G., Avers, P.E., King, T., and McNab, W.H., eds. 1994. Ecoregions and subregions of the United States (map). Presentation scale 1:7,500,000, colored. Wash., DC: USDA Forest Service. Cleland, D.T., Avers, P.E., McNab, W.H., Jensen, M.E., Bailey, R.G., King, T., and Russell, W.E. 1997. National hierarchical framework of ecological units. In: Boyce, M.S., and Haney, A., eds., Ecosystem management applications for sustainable forest and wildlife resources. New Haven, CT: Yale University Press, pp. 181-200. Cleland, D.T., Freeouf, J.A., Keys, J.E., Nowacki, G.J., Carpenter, C.A., and McNab, W.H. 2007. Ecological subregions: sections and subsections for the conterminous United States (map). Presentation scale 1:3,500,000, colored. Gen. Tech. Rep. WO-76D [CD-ROM] (Sloan, A.M. cartographer). Washington, DC: USDA Forest Service. ECOMAP. 2007. Delineation, peer review, and refinement of subregions of the conterminous United States. Gen. Tech. Rep. WO-76A. Washington, DC: USDA Forest Service. Frelich, L.E., Ek, A.R., Zobel, J.M., and Page, K. 2012. Forest wildlife habitat description and data for Minnesota species. Staff Paper Series No. 219. St. Paul, MN: University of Minnesota, Department of Forest Resources. Available online at https://conservancy.umn.edu/handle/11299/170665. Hanson, D.S., and Hargrave, B. 1996. Development of a multilevel ecological classification system for the state of Minnesota. Environmental Monitoring and Assessment 39:75-84. Jaakko Pöyry Consulting, Inc. 1992a. Forest wildlife: A technical paper for a generic environmental impact statement on timber harvesting and forest management in Minnesota. Tarrytown, NY: Jaakko Pöyry Consulting, Inc. Prepared for the Minnesota Environmental Quality Board, St. Paul, MN. Available online at https://conservancy.umn.edu/handle/11299/169578. Jaakko Pöyry Consulting, Inc. 1992b. Maintaining productivity and the forest resource base: A technical paper for a generic environmental impact statement on timber harvesting and forest management in Minnesota. Tarrytown, NY: Jaakko Pöyry Consulting, Inc. Prepared for the Minnesota Environmental Quality Board, St. Paul, MN. Available online at https://conservancy.umn.edu/handle/11299/169578. McNab, W.H., and Avers, P.E. 1994. Ecological subregions of the United States: Section descriptions. WO-WSA- 5. Washington, DC: USDA Forest Service. McNab, W.H., Cleland, D.T., Freeouf, J.A., Keys, J.E., Nowacki, G.J., and Carpenter, C.A., comps. 2007. Description of ecological subregions: Sections of the conterminous United States [CD-ROM]. Gen. Tech. Report WO-76B. Washington, DC: USDA Forest Service. Minnesota Department of Natural Resources (MNDNR). 1999. Ecological subsections (map). St. Paul, MN: Minnesota Department of Natural Resources, Division of Forestry. Available online at http://files.dnr.state.mn.us/natural_resources/ecs/subsection.pdf. U.S. Department of Agriculture (USDA). 2007. Ecological subregions: Sections and subsections of the conterminous United States [CD-ROM]. Gen. Tech. Rep. WO-76. Washington, DC: USDA Forest Service. Zobel, J.M., and Ek, A.R. 2014. The Wildlife Habitat Indicator for Native Genera and Species (WHINGS): Methodology and application. Staff Paper Series No. 231. St. Paul, MN: University of Minnesota, Department of Forest Resources. Available online at https://conservancy.umn.edu/handle/11299/170677. Zobel, J.M., Ek, A.R., and Edgar, C.B. 2021. Assessing the impact of 41 years of forest management on native wildlife habitat in Minnesota, USA. Journal of Forestry 119(2):164-176. 3