12 



NORTH AMERICAN FAUNA 73 



In general, these practices have been accomplished on upland sites in the 

 northern areas of the Central Plain and throughout the Northern Highland. 

 Trembling aspen is the primary tree species associated with Deciduous Clear 

 Cuts. Additional tree and shrub species that are important components of 

 clear cuts include ironwood, hazelnut, sugar maple, and basswood. Impor- 

 tant ground layer species include black raspberry, big-leaf aster, rice grass, 

 bottle-brush grass, Pennsylvania sedge, northern bedstraw, bracken fern, 

 and wood anemone. In wet-mesic sites bunchberry and large-flowered tril- 

 lium are also important. 



Deciduous Clear Cuts and associated edge habitat probably support the 

 greatest diversity of breeding birds among the habitats in the Valley. Princi- 

 pal breeding species include ruffed grouse, ruby-throated hummingbird, 

 eastern kingbird, alder flycatcher*, house wren, gray catbird*, brown 

 thrasher, eastern bluebird, golden-winged warbler*, Nashville warbler, yel- 

 low warbler, chestnut-sided warbler*, mourning warbler*, common yellow- 

 throat*, Canada warbler*, brown-headed cowbird, rose-breasted grosbeak, 

 indigo bunting*, American goldfinch, white-throated sparrow*, and song 

 sparrow. 



Coniferous Communities 



Upland Coniferous Forest 



Before settlement of the Valley most of the Central Plain and Northern 

 Highland was covered with Upland Coniferous Forest. Logging activities 

 during the late 1800's and early 1900's altered much of this habitat; very few 

 stands of pure Upland Coniferous Forest still exist. Probably the best repre- 

 sentative stands occur in and near St. Croix State Park in Pine County and 

 Lucius Woods State Park in Douglas County. In most instances this habitat 

 occurs as small relicts intermixed with several Upland Deciduous Forest 

 species. This habitat type is included because of its past dominance and 

 existing relict stands. 



Principal tree species associated with Upland Coniferous Forest are white 

 pine and red pine. Important invaders include white birch, trembling aspen, 

 red maple, sugar maple, black cherry, hazelnut, and ironwood. Prevalent 

 ground layer vegetation includes wood anemone, wild sarsaparilla, big-leaf 

 aster, Pennsylvania sedge, blue bead Uly, bunchberry, wintergreen, ground 

 pine, Canada mayflower, partridge berry, starflower, Indian pipe, and dwarf 

 ginseng. 



Important breeding bird species of the Upland Coniferous Forest include 

 sharp-shinned hawk, pileated woodpecker, hairy woodpecker, eastern wood 

 pewee, blue jay, common raven, black-capped chickadee, red-breasted nut- 

 hatch, hermit thrush, black-and-white warbler, yellow-rumped warbler, pine 

 warbler*, Blackburnian warbler*, ovenbird, purple finch, pine siskin, dark- 

 eyed junco, and chipping sparrow. 



Lowland Coniferous Forest 



This habitat type occurs in numerous locations north of the Tension Zone. 

 The frequency of the Lowland Coniferous Forest is high but is Hmited in 



