Red Spruce Rocky Summit

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System: Terrestrial
Subsystem: Woodland
PA Ecological Group(s): Acadian – Appalachian Red Spruce – Fir – Hardwood Forest

Global Rank:G4 rank interpretation
State Rank: S1

Red Spruce Rocky Summit
Red Spruce Rocky Summit, PNHP

General Description

This type is similar to spruce-fir balds found to the north and south (at high elevations) of Pennsylvania but lacks the fir component (balsam fir to the north, Fraser fir to the south) found in those communities. It is known in this state from only one example, Bartlett Mountain in Wyoming County, Northeastern Pennsylvania. The site is north-facing on fractured bedrock at an elevation of about 2200’. Woody species occur in pockets of soil that have accumulated in cracks in the bedrock. There are extensive areas of bare or lichen-encrusted rock. Aside from red spruce (Picea rubens), tree species include gray birch (Betula populifolia), pitch pine (Pinus rigida), red pine (P. resinosa), eastern white pine (P. strobus), eastern hemlock (Tsuga canadensis), and red maple (Acer rubrum). Trees are small in stature and shaped by exposure to wind and ice. Shrubs include black huckleberry (Gaylussacia baccata), low sweet blueberry (Vaccinium angustifolium), lowbush blueberry (V. pallidum), black chokeberry (Aronia melanocarpa), American mountain-ash (Sorbus americana), mountain holly (Ilex montana), and sheep laurel (Kalmia angustifolia). Herbaceous species include Pennsylvania sedge (Carex pensylvanica), sedge (Carex communis), common hairgrass (Deschampsia flexuosa), Canada mayflower (Maianthemum canadense), and cow-wheat (Melampyrum lineare). Reindeer lichens (Cladonia spp. and Cladina spp.) and crustose lichens are abundant. At the one known site for this community type, there are pockets of small wetland areas in low bedrock concavities scattered; which may be a factor in the presence of red spruce and hemlock. The particularly northern character of this site may also be due to a combination of extreme environmental factors: exposure from steep northern and eastern slopes, high elevation, history of fire, and frost pocket effect. This community type is part of the Ridgetop Acidic Barrens Complex.

Rank Justification

This type is Pennsylvania Endangered because only one location is known in the state.


  • A woodland found on acidic bedrock outcrops or summits, with red spruce in tree canopy
  • Heath species (black huckleberry, sheep laurel, lowbush blueberry) present in shrub layer
  • Herbaceous species reflect dry, acidic environment

* limited to sites with higher soil calcium
Vascular plant nomenclature follows Rhoads and Block (2007). Bryophyte nomenclature follows Crum and Anderson (1981).

International Vegetation Classification Associations:

USNVC Crosswalk:


Representative Community Types:

Northern Appalachian Red Spruce Rocky Ridge (CEGL006053)

NatureServe Ecological Systems:


NatureServe Group Level:

Acadian-Appalachian Red Spruce - Fir - Hardwood Forest (G744)

Origin of Concept

Fike, J. 1999. Terrestrial and palustrine plant communities of Pennsylvania. Pennsylvania Natural Diversity Inventory. Pennsylvania Department of Conservation and Recreation, Bureau of Forestry, Harrisburg, PA. 86 pp.

Gawler, S. C. 2003. Northern Appalachian Red Spruce Rocky Ridge (CEGL006053). NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available (Accessed: January 27, 2022).

Pennsylvania Community Code*

JS : Red Spruce Rocky Summit

*(DCNR 1999, Stone 2006)

Similar Ecological Communities

Within Pennsylvania, the Pitch Pine – Heath Woodland is also a dry woodland type found on acidic summits, but lacks red spruce, and has a greater dominance of pitch pine and in some cases, also has a minor component of oaks in the canopy. A history of fire may be more important for the Pitch Pine – Heath Woodland type, while a northern aspect/cool microclimate may be more important for the Red Spruce Rocky Summit. The Pennsylvania example of this community type lacks the fir component of spruce balds found at high elevations both farther north in the Adirondacks (balsam fir), and farther south in the Blue Ridge (Fraser fir) North of Pennsylvania, the floristically similar Red Spruce Talus Slope Woodland (CEGL006250) occurs on talus, while the Red Spruce Rocky Summit is found on bedrock ridges and outcrops.

Fike Crosswalk

Red Spruce Rocky Summit

Conservation Value

This is the only example in Pennsylvania of a spruce bald, a community type found to the north and south of the state. Red spruce is fairly uncommon in Pennsylvania, as it is predominantly a more northern species. Red spruce is also a host tree for dwarf mistletoe (Arceuthobium pusillum). Several species of Cladonia lichens documented from this site appear to be disjunct from their main populations further north (Lendemer pers. comm.). Bryophytes and invertebrates have not yet been investigated here and may include other northern disjunct species.


Red spruce can be damaged by a number of pests, most notably the spruce budworm (Choristoneura fumiferana). Red spruce is also very susceptible to fire damage. Red spruce grows best in a cool, moist climate, and is therefore threatened by increasing temperatures. It is projected to decline in climate models due to low-adaptability characteristics such as regeneration difficulty and susceptibility to fire (Peters et al., 2020). Loss of red spruce at the Bartlett Mountain site would eliminate this community type in Pennsylvania.


The most important management needs are monitoring and maintaining the health of red spruce, and investigating appropriate fire management for the site. Parts of the Bartlett Mountain bald were burned for blueberries up until the 1950s (F95RHO02), and therefore fire may be important over the long-term in maintaining the open character of the community; however, red spruce is also very sensitive to fire.

Research Needs

The importance of this community type to lepidopterans and other animal species should be examined. Bryophyte surveys should be conducted in more detail. Inventory should also be conducted to determine whether there are additional locations for this community type in Pennsylvania.


Since pre-settlement times, red spruce has declined in Pennsylvania due to widespread clearcutting and subsequent fire. More recent trend information is not available, especially because only one site is currently known in the state for this community type.

Range Map

range map

Pennsylvania Range

The Red Spruce Rocky Summit is found in one location within the following USEPA Level III (IV) Ecoregion: Northern Central Appalachians (62).

Global Distribution

Maine, New Hampshire, New York, Pennsylvania, Vermont, New Brunswick (Canada)

Burns, R. M., & Honkala, B. H. (1990). Silvics of North America: Hardwoods. U.S. Department of Agriculture, Forest Service.

Peters, M. P., Prasad, A. M., Matthews, S. N., & Iverson, L. R. (2020). Climate change tree atlas, Version 4. U.S. Forest Service, Northern Research Station and Northern Institute of Applied Climate Science, Delaware, OH.

Cite as:
Braund, J., E. Zimmerman, A. Hnatkovich, and J. McPherson. 2022. Pennsylvania Natural Heritage Program. Red Spruce Rocky Summit Factsheet. Available from: Date Accessed: May 19, 2024

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