The Upland Prairie-Forest Continuum*

Attributes

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Mesic Forests

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Dry-mesic Forests

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Dry-mesic Woodlands

/ Dry Woodlands and Flatwoods /

Savannas

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Prairies

Vegetation layers / Multiple 4 / Multiple > 3 / 2 to 3 / 2 to 3 / 2 / 1
Canopy Height-ft / 90+ / 70-90 / 60-90 / 20-60 / 20-60 / Not applicable
Tree Form / Narrow crowns, clean trunks / Narrow crowns, clean trunks / Somewhat spreading crowns, some lower spreading branches / Spreading crowns, some lower spreading branches / Wide-spreading crowns, lower branches typical / Not applicable
Canopy closure / 90-100 / 90-100 / 80+ / 30-80 / 10-30 / 0-10
% Understory Cover / 50-100, dense / 50-100, dense / 30-50, patchy / 10-30, scattered / 5-10, sparse / 0-10
Ground Layer Cover / Dense in spring, patchy to sparse by mid-summer / Dense to patchy in spring, patchy to sparse by mid-summer / Dense to patchy in spring, patchy to dense by mid-summer / Patchy to dense all season / Dense all season / Dense all season
Ground Layer Plants / Rich diversity of spring ephemerals, and ferns; few summer/fall forbs / Moderate to low diversity of spring ephemerals, and ferns; few summer/fall forbs / Moderate to low diversity of spring ephemerals, and ferns; abundant C3 grasses, sedges, and summer/fall forbs / C3 and C4 grasses, sedges, diversity of forbs all season / C4 grasses, sedges, diversity of forbs all season / C4 grasses, sedges, diversity of forbs all season
Topography and Landform / Protected valleys, ravines, bluff bases, lower slopes of northerly aspects, fire shadow areas / Mid and upper slopes of northerly aspects, ravines, other aspects in fire shadow areas / Mid and upper slopes of southerly aspects, fire prone landscapes / Steep upper slopes of southerly aspects, narrow ridges, broad ridges, fire prone landscapes / Level to gently rolling topography, steep loess hills, broad ridges / Level to gently rolling plains, steep loess hills, broad ridges
Soils / Deep ( 3') loams, nutrient rich, high organic matter, deep leaf litter / Moderate depth (24-36") silt loams, moderate organic matter, moderately deep leaf litter / Moderate depth (20-36") silt loams, moderate organic matter, shallow leaf litter / Shallow depth (<20"), droughty, often rocky and or nutrient poor; fragipans or claypans / Wide range of soil types from shallow to deep, variably rocky / Wide range of soil types from shallow to deep, variably rocky
Fire Regime -
(Restoration/
Maintenance) / Very infrequent, low intensity (historically every 30+ years?) / Infrequent, low intensity (historically every 20+ years?) / Low to moderate intensity fires (2-3 years / 3-10 years) / Low to moderate intensity fires (1-3 years / 3-7 years) / Moderate intensity fires (1-4 years / 3-5 years) / Moderate to high intensity fires every 1 to 3 years
Dominant Trees / Red oak, sugar maple, ash, basswood, walnut / White, red, and black oaks, hickories / White, black, scarlet, chinkapin oaks, hickories, shortleaf pine / Post, blackjack, chinkapin, bur, white oaks, shortleaf pine / Bur, chinkapin, post, swamp white, and white oaks / Not applicable
Characteristic Plants / Spicebush, Paw Paw, Trilliums, Bloodroot, Dutchman’s Breeches / Meadow Rue, Trout Lily, Christmas Fern, Black Cohosh, Dwarf Larkspur / Bristly Sunflower, Asters, Goldenrods, Bee Balm, Sedges, Native C3 Grasses / Leadplant, Asters, Wild Quinine, Goldenrods, Pale Purple Coneflower, Native Lespedezas / Compass Plant, Rattlesnake Master, Rigid Goldenrod, Native C4 Grasses / Compass Plant, Rattlesnake Master, Rigid Goldenrod, Native C4 Grasses
Basal Area (ft2/ac) / 90-100 / 80-100 / 50-80 / 30-60 / <30 / <10

* Note: This chart describes idealized conditions for stands that best represent their pre-settlement character. For most sites, these will be the desired future conditions in terms of structure.