Defined: Natural Community (MNís St. Croix River Valley and Anoka Sandplain, Weaver, et al): An assemblage that tends to reoccur over time and space, of native plants and animals species. Natural communities are classified and described according to their vegetation, successional status, topography, hydrological conditions, landforms, substrates, soils, and natural disturbance regimens (such as wildfires, windstorms, normal flood cycles, and normal infestations by native insects and microorganisms).
Regional Examples: Algific Talus Slope, Calcareous Fen, Cedar Glade, Dry Cliff, Dry Prairie, Dry-Mesic Prairie, Emergent Aquatic, Ephemeral Pond, Floodplain Forest, Forested Seep, Hemlock Relict, Mesic Prairie, Moist Cliff, Oak Barrens, Oak Opening, Oak Woodland, Pine Barrens, Pine Relict, Sand Barrens, Sand Prairie, Shrub-Carr, Southern Dry Forest, Southern Dry-Mesic Forest, Southern Hardwood Swamp, Southern Mesic Forest, Southern Sedge Meadow, Submergent Aquatic, Talus Forest, Wet Prairie, Wet-Mesic Prairie
The Oak Savanna Eco-Region (map from Nuzzo, 1994):
Often simply described as the eco-tone between the Eastern Deciduous Forest and the Great Plains Prairie, many distinct natural communities collectively make up the Oak Savanna Eco-Region. The natural communities of the Upper Mississippi Oak Savanna Eco-Region are the product of a convergence of floristic elements from all points of the compass, molded and balanced by regional environmental factors such as weather and climate, soils and wildfire. Through the concept of natural community has well established utility for understanding and describing these systems, perhaps "natural continuum," or better still, "natural continua" more accurately portray the complexity and inter connectedness of the ecosystem.
However we attempt to quantify it, the Upper Mississippi Oak Savanna Eco-Region is...
...one of the world's most endangered ecosystems (Ricketts et al., 1999)
...biodiversity is extremely high (USFWS)
...Perhaps millions of acres of degraded but potentially recoverable oak ecosystems remain. (Leach and Ross, 1995)
...the land dripped with richness. (Stienbeck, 1962)
...once healthy ecosystems that covered this land no longer support their original diversity of life. (Leach and Ross, 1995)
...Little scientific information exists about oak savanna (Nuzzo, 1986)
...beggars all description (Smith, 1837)
...Management should be carried out using a landscape scale ecosystem approach that includes a long-term perspective, and an emphasis on preserving ecological structure and function. (Henderson, 1993)
...a value which is beyond computation. (Hoyt, 1860)