10 



NORTH AMERICAN FAUNA 73 



Deciduous Forest Communities 



Northern Hardwood Forest 



This floristic community extends throughout the Northern Highland and 

 much of the Central Plain north of St. Croix Falls (Polk and Chisago coun- 

 ties). Characterized by a mixture of coniferous and deciduous tree types, the 

 Northern Hardwood Forest occurs on a wide range of topographic sites and 

 on many soil types. Mesic sites support white birch, sugar maple, hemlock, 

 basswood, and red oak. Important coniferous species of this habitat are red 

 pine, white pine, and to a Umited extent jack pine. Depending on the extent 

 of early successional stages this is generally a cUmax or near-climax com- 

 munity. 



Prevalent within the shrub layer and among ground layer species are 

 beaked hazel, bracken fern, wood anemone, wild sarsaparilla, big-leaf aster, 

 blue bead Uly, northern bedstraw, ground pine, Canada mayflower, bishop's 

 cap, Solomon's seal, twisted stalk, starflower, downy yellow violet, rice 

 grass, and Pennsylvania sedge. 



Characteristic breeding birds include broad-winged Hawk*, ruffed 

 grouse*, great horned owl, barred owl, black-billed cuckoo*, common flicker, 

 yellow-belUed sapsucker*, hairy woodpecker*, downy woodpecker, great 

 crested flycatcher, least flycatcher*, eastern wood pewee*, blue jay, north- 

 ern raven, black-capped chickadee, white-breasted nuthatch, American 

 robin, wood thrush, veery*, solitary vireo, red-eyed vireo*, black-and-white 

 warbler, chestnut-sided warbler, ovenbird*, American redstart, northern 

 oriole, scarlet tanager, rose-breasted grosbeak*, and white-throated 

 sparrow. 



Lowland Deciduous Forest 



This rich deciduous community occurs primarily along the floodplains of 

 larger streams and rivers adjacent to the St. Croix in the Western Upland 

 and Central Plain. The abundant soil moisture from river flooding and high 

 water table is a principal microcUmatic feature of this community. Because 

 of its southern plant affinity. Lowland Deciduous Forest attracts some typi- 

 cally southern breeding bird species that occur in no other habitat type. 

 Major tree species characteristic of this community are silver maple, Ameri- 

 can elm, green ash, red oak, basswood, and cottonwood. 



Prevalent species in the shrub layer are black willow, box-elder, and gray 

 dogwood. Depending on the amount of disturbance by grazing cattle, tar- 

 tarian honeysuckle and prickly ash approach dominance in the shrub layer. 

 Important among ground layer species are jack-in-the-pulpit, toothwort, 

 Virginia waterleaf, wood nettle, poison ivy, germander, hedge nettle, jewel- 

 weed, and skunk cabbage. 



Characteristic breeding bird species of the Lowland Deciduous Forest 

 include great blue heron*, wood duck*, red-shouldered hawk*, yellow-billed 

 cuckoo, screech owl*, barred owl*, pileated woodpecker*, red-belUed wood- 

 pecker*, downy woodpecker, eastern wood pewee, tufted titmouse*, white- 

 breasted nuthatch*, blue-gray gnatcatcher*, yellow-throated vireo*, warb- 

 Ung vireo*, blue- winged warbler*, yellow warbler, cerulean warbler*, 



