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Upland Prairies occur on a range of landforms in the prairie zone, from nearly flat glacial
<br />lakeplains to steep morainic slopes. In the deciduous forest - woodland zone, prairies occur on
<br />droughty, level outwash areas and steep south - and west - facing slopes. The pre - European
<br />settlement distribution of prairie was related to the interaction of local fire frequency with growth
<br />rates of woody species: where conditions were favorable for rapid growth, more frequent fires
<br />were necessary to maintain prairie over savanna, woodland, or forest. Fragmentation of Upland
<br />Prairie since European settlement has reduced fire frequency throughout the prairie and
<br />deciduous forest - woodland zones, and most prairie remnants have more brush and trees than
<br />were present in the past.
<br />Mesic Prairie is a dry-mesic to wet -mesic grassland that occurs mainly in the prairie zone in
<br />southern and western Minnesota and sporadically in the deciduous forest - woodland zone. Mesic
<br />Prairie is dominated by grasses. Big bluestem (Andropogon gerardii), Indiangrass (Sorghastrum
<br />nutans), and prairie dropseed (Sporobolus heterolepis) are the major native species on most sites,
<br />with little bluestem (Schizachyrium scoparium) and porcupine grass (Stipa spartea) important on
<br />drier sites, and switchgrass (Panicum virgatum) and prairie cordgrass (Spartina pectinata)
<br />common on wetter sites. The introduced grass Kentucky bluegrass (Poa pratensis) is present at
<br />most sites; its is a function of the site's disturbance history.
<br />Forbs are abundant (but usually subdominant to grasses) and have high local diversity. Forb
<br />species - composition also varies locally with soil moisture. There is greater regional variation
<br />among forbs than among grasses. Common forb species include purple prairie- clover
<br />(Petalostemon purpureum), white prairie- clover (P. candidum), ground -plum (Astragalus
<br />crassicarpus), prairie - turnip (Psoralea esculenta), rough blazing -star (Liatris aspera), Canada
<br />goldenrod (Solidago canadensis), stiff goldenrod (S. rigida), Missouri goldenrod (S.
<br />missouriensis), prairie thistle (Cirsium flodmani), smooth aster (Aster laevis), stiff sunflower
<br />(Helianthus rigidus), Maximilian sunflower (H. maximiliani), smooth rattlesnake -root
<br />(Prenanthes racemosa), white sage (Artemisia ludoviciana), wood lily (Lilium philadelphicum),
<br />white camas (Zigadenus elegans), heart- leaved alexanders (Zizia aptera), prairie larkspur
<br />(Delphinium virescens), downy phlox (Phlox pilosa), hoary puccoon (Lithospermum canescens),
<br />tall cinquefoil (Potentilla arguta), alum -root (Heuchera richardsonii), wood - betony (Pedicularis
<br />canadensis), northern bedstraw (Galium boreale), prairie bird -foot violet (Viola pedatifida),
<br />oval - leaved milkweed (Asclepias ovalifolia), and showy milkweed (A. speciosa). Purple
<br />coneflower (Echinacea angustzfolia) is common on drier sites in the western part of the
<br />community's range. Leadplant, prairie rose, sand cherry, wolfberry, and prairie willow are
<br />common low -shrub or sub -shrub species. Fragrant false indigo is common on moister sites.
<br />Trees and taller brush often occur along the margins of wetlands adjacent to Mesic Prairies.
<br />Mesic Prairie is a fire- dependent community. In the absence of fire, occurrences of Mesic
<br />Prairie are invaded by brush and trees. In the prairie zone, Mesic Prairie occurs on nearly level
<br />glaciolacustrine and glaciofluvial deposits, and on flat or gently rolling morainic landforms. In
<br />southeastern and, to a lesser extent, southwestern Minnesota, the glacial deposits are overlain by
<br />loess. Bedrock subtypes of Mesic Prairie exist in a few areas where bedrock is within about one-
<br />and- one - quarter meters of the ground surface and there are numerous small patches of exposed
<br />rock. Within the deciduous forest - woodland zone, Mesic Prairie usually occurs on level outwash
<br />areas or on broad, sandy river terraces.
<br />Foxborough Conservation Development Restoration and Management Plan 20
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