Common (Translated Scientific) Name: Common Juniper - (Eastern Red-cedar) - Fragrant Sumac - Downy Arrow-wood / Prairie Goldenrod Shrubland

Colloquial Name: Juniper Alvar Shrubland

Hierarchy Level:  Association

Type Concept: The juniper alvar shrubland type occurs throughout the Great Lakes region of the United States and Canada, in northern New York, southern Ontario, northern Ohio, northern Michigan, and eastern Wisconsin. Stands occur on very shallow soils (usually less than 30 cm deep) over flat limestone outcrops (pavements). Moisture varies over the season, but summer droughts are typical. Juniper alvar shrublands often occur in a patchy landscape mosaic with other alvar communities, including tufted hairgrass wet alvar grassland, little bluestem alvar grassland, annual alvar pavement-grassland, alvar nonvascular pavement, and poverty grass dry alvar grassland. Grikes (eroded cracks in the rock up to 2 m or more deep and extending 5-30 m in length) may occur, with shrubs and trees rooted in the cracks. Shrubs dominate, with over 25% cover of tall, short, and dwarf-shrubs; the average is about 43% cover of shrubs, with less than 10% of that being tall shrubs. Characteristic tall shrubs (2-5 m tall) are scrub forms of trees such as Juniperus virginiana, Thuja occidentalis, and Quercus macrocarpa. Tree forms (>5 m tall) of these species may be present, but trees have less than 10% cover in the community. Other less common trees (>5 m tall) that may be present include Carya ovata, Ulmus thomasii, and Fraxinus americana. Characteristic short shrubs (0.5-2 m tall) include Juniperus communis, Cornus racemosa, Rhus aromatica, Prunus virginiana, and Viburnum rafinesqueanum. Some dwarf-shrubs (under 0.5 m tall) are usually present, including Arctostaphylos uva-ursi and Symphoricarpos albus. Characteristic vines include Toxicodendron radicans and Vitis riparia. The herb layer forms a dry, grassy meadow between the shrubs; average cover of herbs is about 23%. The most abundant herbs are Danthonia spicata, Oligoneuron album, and Carex umbellata. Less than 50% of the ground surface is exposed limestone bedrock, which is usually covered with lichens, mosses, and algae.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: More northern stands may be more heavily dominated by Juniperus communis, and species such as Abies balsamea, Aquilegia canadensis, Arctostaphylos uva-ursi, and Picea glauca may be more common, and deciduous trees and shrubs are less common. Juniper Alvar Shrublands often occur in a patchy landscape mosaic with other alvar communities, including Tufted Hairgrass Wet Alvar Grassland, ~Deschampsia cespitosa - (Sporobolus heterolepis, Schizachyrium scoparium) - Carex crawei - Packera paupercula Grassland (CEGL005110)$$; Little Bluestem Alvar Grassland, ~Sporobolus heterolepis - Schizachyrium scoparium - (Carex scirpoidea) / (Juniperus horizontalis) Grassland (CEGL005234)$$; Annual Alvar Pavement-Grassland, ~Sporobolus neglectus - Sporobolus vaginiflorus - Trichostema brachiatum - Panicum philadelphicum - (Poa compressa) Alvar Grassland (CEGL005235)$$; Alvar Nonvascular Pavement, ~Tortella tortuosa - Cladonia pocillum - Placynthium spp. Sparse Vegetation (CEGL005192)$$; and Poverty Grass Dry Alvar Grassland, ~Danthonia spicata - Poa compressa - (Schizachyrium scoparium) Grassland (CEGL005100)$$.

Similar NVC Types: No Data Available

note: No Data Available