University of Minnesota
University of Minnesota
College of Biological Sciences
Black bear with cubs.Uvularia perfoliata blooming in woodland shade. Mesic upland forest.

Upland woods

We will consider here six categories of wooded uplands. All occur on the sandy upland soils of the Anoka Sandplain. On the basis of canopy coverage they can be variously assigned to savanna (<30%), woodland (<70%), and forest (>70%). At Cedar Creek the litter layer is generally minimal, and soils can be quite droughty. Several tracts of Dry Oak Woodland are found in the southern half of Cedar Creek. Most extensive are fire-exposed or fire prone tracts of Dry Oak Forest. Isolated knolls surrounded by fire protecting swamp have a more Big Woods character and are designated Mesic Upland Forest. There are also a few wooded tracts of northern character with pine inclusions and are here designated Mixed Conifer-Hardwood Forest. Trembling aspen clones occur at wood-field ecotones and are considered here as Aspen Woodland. Finally, flanking many of the uplands are strips of Lowland Hardwood Forest. See Trees, Conifers, Subcanopy Trees and Upland Shrubs for images of common woody plants at Cedar Creek.

Dry Oak woodland

Most of these occur in the southern half of Cedar Creek, and several of them are in the Burn Program. Canopy coverage ranges from 30-70%, and in consequence they are generally quite brushy beneath. However, in aspect they can be strikingly different depending upon the dominant trees present and the unit’s past burn history. Overgrown Savanna occurs in Unburned Plots where the dominant trees are open grown Bur Oaks (Quercus macrocarpa). Species of Amelanchier (Juneberries) and Prunus (Cherries) are common in this habitat. The open canopy and the absence of fire has allowed these compartments to ‘brush up’ with hazel, sumac, and blackberry, eliminating most reminders of their savanna past. Excellent examples can be found in TMS, FLSW, SHS, and OMS. Scrub Oak Woodland occurs in areas of infrequent but intense burns where Northern Pin Oak (Quercus ellipsoidalis) is the dominant tree. The canopy oaks are progressively being eliminated, but the understory brushes up with Pin Oak saplings. Examples of this can be found in FLNW, FLW, and portions of SWB.

Dry Oak forest

The dominant tree on the sandy wooded uplands of Cedar Creek is Quercus ellipsoidalis (Northern Pin Oak). There is some hybridization between it and the less common Quercus rubra (Red Oak). Pin Oak has deeply dissected leaves with pointed tips and its acorns are slender with a deep cap. Red Oak leaves while point-tipped are broader and less deeply dissected. Acorns are large robust things with a shallow cap. Another characteristic of Pin Oaks is the retention of dried leaves throughout the winter and the holding onto dead lower limbs for many seasons. One commonly finds individuals with multiple trunks (indicative of past logging or fires) and many of these woodlots have been pastured in the past. The ground flora and understory is not very exciting. These forests do not have a show of spring ephemerals. Carex pensylvanica (Pennsylvania Sedge) is an abundant groundlayer graminoid and Pteridium aquilinum (Bracken Fern) is a common fern. Some of the more characteristic flowering plants are Geranium maculatum (Wild Geranium), Aquilegia canadensis (Columbine), Smilacina stellata and S. racemosa (Starry and False Solomon Seal).

Mesic Upland forest

These forests are confined to fire protected knolls and adjacent uplands that are embedded within a swampy matrix. While not boasting the diversity of some of the Big Woods of south-central Minnesota, they harbor many species that are otherwise absent from the fireprone Anoka Sandplain. Most visited is Crone’s Knoll on the trail into Cedar Bog Lake. It is our best, though not a typical, example of Maple-Basswood Forest. In addition to Acer saccharum (Sugar Maple) and Tilia americana (Basswood) one finds Quercus rubra (Red Oak), Quercus alba (White Oak), Betula papyrifera (Paper Birch), Acer rubrum (Red Maple) and also Pinus strobus (White Pine). Ostrya virginiana (Ironwood) is a common subcanopy tree, and there are isolated individuals of Carpinus caroliniana (Blue Beech). The understory has a rather open character. The dense shade cast by the canopy trees permits very few shrubs to grow. Sugar Maple seedlings are abundant. Characteristic graminoids are Carex pensylvanica (Pennsylvania Sedge) and Oryzopsis asperifolia (Mountain Rice Grass). Here one can find such spring ephemerals as Hepatica americana and H. acutiloba (Round and Sharp-lobed Hepatica), Anemone quinquefolia (Wood Anemone), and Viola pubescens (Woolly Violet). Trillium nivale and T. grandiflora (Snow and Large-flowered Trillium), Sanguinaria canadensis (Bloodroot), Uvularia grandiflora (Large-flowered Bellwort), and Phlox divaricata (Woodland Phlox) are also present. However, the occurrence of the last-mentioned species is suspect (i.e. were likely planted by Mrs. Crone) as they occur on no other knolls at Cedar Creek.

Other knolls and uplands near Cedar Bog Lake are Katie’s Knoll, Deer Trap Knoll, and Skunk Cabbage Knoll. Knolls situated in Channel Marsh south of the Lab include Lawrence Cabin Knoll, Chipmunk Run, Dead Elm Knoll, Lost Knoll, Leap Frog Island, and Turkey Island. All deserve reinspection to develop a Flora Listing. However, this is a rather daunting task as it must be undertaken during Deerfly Season, if one wishes to do an adequate job. A wildfire passed over the knolls south of the Lab in 1955?, and likely eliminated many mesic species, at least for the short term.

Mixed conifer-hardwood forest

A few upland wooded tracts in North Section (Ice Lake Stand, Big Buck Ridge, Pine Ridge) have inclusions of pines and give the area a distinctly northern flavor. Pinus strobus (White Pine) is most common and is widely scattered throughout North Section. Isolated trees occur even in the extensive swamps found there. A natural stand of P. resinosa (Red Pine) is found at the western extremity of Pine Ridge north of Cedar Bog Lake. Although appearing healthy, the Red Pine is not reproducing. The few remaining P. banksiana (Jack Pine) in North Section are dying and not reproducing. Jack Pine is a short-lived tree with resinous cones requiring periodic fires to replace itself. Common Hardwood associates are Quercus rubra (Red Oak), Populus grandidentata (Big-toothed Aspen) and Acer rubrum (Red Maple). Characteristic groundlayer plants include Aster macrophylla (Large-leaved Aster), Polygonatum pubescens (Hairy-leaved Solomon-seal), Pyrola asarifolia (Pink Shinleaf), Gaultheria procumbens (Wintergreen), Mitchella repens (Partridge Berry), Chimaphila umbellata (Prince’s Pine), and Polygala pauciflora (Gaywings). Gaywings has not been seen since ca 1980.

Aspen woodland

Invading many fields from the perimeter of upland woods are clones of Populus tremuloides (Trembling Aspen). This species sometimes also gets established at marsh edges and in old field swales. This dioecious tree spreads and grows rapidly, establishing nearly pure male or female clones. The buds and catkins are relied upon heavily by wintering ruffed grouse. Populus grandidentata (Big-toothed Aspen) clones are found in a variety of upland forests. These inclusions are generally too small to be mapped. Some noteworthy examples are to be found in Big Buck Ridge, Dumbell Peninsula… There is nothing exceptional about the groundlayer of aspen woodlands.

Lowland hardwood forest

Surrounding many of the knolls as well as the margins of upland woods are generally narrow strips of lowland hardwoods. A small amount of rich organics overlays a sandy substrate. Major canopy trees in this habitat are Acer rubrum (Red Maple), Betula papyrifera (Paper Birch), Betula alleghaniensis (Yellow Birch). These grade into Hardwood, Conifer, Alder or Shrub Swamps. Although relatively small in extent, lowland hardwoods have a relatively diverse groundlayer. Characteristic graminoids are the sedges Carex gracillima, C. pedunculata, and C. deweyana. A common understory plant in damper areas is Osmunda cinnamomea (Cinnamon Fern). Conspicuous flowering plants are Clintonia borealis (Bluebead Lily), Cornus canadensis (Bunchberry), Trientalis borealis (Starflower), Trillium cernuum (Nodding Trillium), and Arisaema triphyllum (Jack-in-the-Pulpit). Corallorrhiza trifida (Coral Root) is a common small orchid. Where lowland hardwoods grade into tamarack or white cedar swamp one may chance encounter other less common orchids: Cypripedium reginae, C. calceolus, C. acaule, C. arietinum (Showy, Yellow, Stemless and Ramshead Lady Slippers).

Birds and mammals of forested upland

The ovenbird with its call of ‘teacher teacher’ is a common ground nester appearing before the canopy closes. Numerous other songbirds find our upland forests an excellent place to raise a family. Wild turkey have become increasingly common in our Oak Forests. They are escapees from a release program initiated on Carlos Avery WMA in 198x. The calls of Barred and Great-horned owls signal the presence of these two raptors. Red-shouldered, Red-tailed, and Coopers Hawks are other common raptors. Winter residents are small in number and include: blue jays and crows, chickadees, nuthatches, downy and hairy woodpeckers, red-bellied and red-headed woodpeckers, pileated woodpeckers…

Our most common forest mammals are also, unfortunately, common road kills. Most numerous are raccoons and gray squirrels, followed by striped skunks, fox squirrels, red squirrels, and white-tailed deer. Red fox is fairly common, Gray fox considerably less. The howl of Coyotes is frequently hear in the summer. An occasional Black bear wandering through the area can give summer interns a start. Bobcats are very elusive but are still likely to occur in some densely wooded areas. A Porcupine sighting was made in 198x. In late fall of 2000 several oppossum were run over on surrounding county roads. This species appears to be expanding its range northward.