Invalid Unit Specified
G161 Pinus rigida Barrens Group

The U.S. National
Vegetation Classification
Type Concept Sentence: This group is characterized by Pinus rigida, and includes open eastern U.S. woodlands of dry, nutrient-poor sites that are influenced by periodic fire.
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Common (Translated Scientific) Name: Pitch Pine Barrens Group
Colloquial Name: Pitch Pine Barrens
Hierarchy Level: Group
Type Concept: This group encompasses woodlands dominated by Pinus rigida, or by Pinus rigida mixed with oak species, occurring on dry and nutrient-poor soils and mostly maintained by fire. Quercus rubra, Pinus strobus, and Betula populifolia are common associates in the north, while Quercus stellata is characteristic in the south. A tall-shrub layer of Quercus ilicifolia, Quercus prinoides, and, south of New England, Quercus marilandica are commonly present, although portions of some barrens (or occasionally the entire barrens) lack the scrub oak component. A well-developed low-shrub layer is typical, with lowbush Vaccinium spp., Gaylussacia baccata, and Comptonia peregrina characteristic. The main constituents of this group are the associations that characterize the pine barrens of sandy substrates in the northeastern United States; the group also contains associations in which Pinus rigida dominates thin-soiled rocky hilltops. Substrates are of two major types: (1) deep sandy soils of outwash plains, stabilized inland sand dunes, and glacial till; and (2) less commonly, thin-soiled outcrops of acidic bedrock along exposed low-elevation ridgelines and upper slopes. The soils are consequently coarse-textured, acidic, mostly well-drained to xeric, and low in nutrients. Pinus rigida is the usual dominant, and cover may range from closed-canopy forest to (more typically) open woodlands.
Diagnostic Characteristics: Trees usually include a component of individuals >5 m tall, or at least not with the dominant canopy <2 m tall; Pinus rigida strongly dominant (usually at least 50% of the canopy cover) in the tree layer; or Pinus rigida the dominant conifer and mixed with oak species (typically Quercus coccinea, Quercus alba, Quercus velutina).
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: This group includes forests and woodlands, but not the dwarf pine plains that are characterized as shrublands. Species composition can be similar in the two groups, but structure and fire frequency, and some edaphic characters, separate them. The southern Ontario classification "Pitch Pine Acidic Treed Rock Barren Type (ON_SO_RBT3-1)" is placed with Pinus rigida / Vaccinium spp. - Gaylussacia baccata Woodland (CEGL005046). In Atlantic Canada, there is a northern analog of this on sandy outwash plains and thin glacial till. It occurs in warmer interior areas of Nova Scotia. Neither Pinus rigida or the southern oaks Quercus ilicifolia and Quercus prinoides are present. The vegetation is characterized by species such as Corema conradii, Gaylussacia baccata, Hudsonia ericoides, Ilex glabra, Photinia spp., and Pinus spp. (usually Pinus resinosa and Pinus strobus). Quercus rubra and Prunus serotina may be present. Either this group (G161) needs to be broadened or a new unit defined. Atlantic Canada also has coastal pine woodlands [see comments under Laurentian Sub-boreal Dry Jack Pine - Red Pine - Oak Woodland Group (G347)] (S. Basquill pers. comm. 2015).
Similar NVC Types:
G160 Great Lakes Pine Barrens, note:
Physiognomy and Structure: The tree layer has a highly variable canopy, ranging from closed-canopy forest to scattered woodland canopy over shrubs. In most cases, canopy closure increases with time since major fire disturbance. The canopy layer may be strongly pine-dominated, or a pine-oak mix (very rarely without pine). A shrub layer of 1- to 2-m Quercus ilicifolia and/or Quercus prinoides is often present and may be dense. Where this shrub layer is not well-developed, a dwarf-shrub layer of Vaccinium spp. and/or Gaylussacia spp. may be extensive. Development of the herb layer varies with the cover of overtopping vegetation.
Floristics: Pinus rigida is the dominant and characteristic species of this group. Quercus ilicifolia and Quercus prinoides are typical shrubby oaks. Tree oaks include Quercus alba, Quercus coccinea, and Quercus velutina. Low shrubs are usually dominated by heaths and include Vaccinium pallidum, Vaccinium angustifolium, and Gaylussacia baccata. Photinia melanocarpa and Corema conradii may be locally common. Characteristic herbs include Carex pensylvanica, Piptatherum pungens, Schizachyrium scoparium, Melampyrum lineare, Lysimachia quadriflora, and Baptisia tinctoria. Most of the herb and shrub species can occur both on sandy and rock substrates. In Atlantic Canada, there is a northern analog of this on sandy outwash plains and thin glacial till. It occurs in warmer interior areas of Nova Scotia. Neither Pinus rigida or the southern oaks Quercus ilicifolia and Quercus prinoides are present. The vegetation is characterized by species such Corema conradii, Gaylussacia baccata, Hudsonia ericoides, Ilex glabra, Photinia spp., and Pinus spp. (usually Pinus resinosa and Pinus strobus). Quercus rubra and Prunus serotina may be present (S. Basquill pers. comm. 2015).
Dynamics: Pitch pine barrens on sandplains are highly dependent on fire to maintain pine dominance. Frequency of fire is an important determinant of community structure as well as composition. On rocky ridges and in exposed maritime settings, Pinus rigida may persist without frequent fire. The degree of serotiny in Pinus rigida cones varies across environmental settings, with those of sandy pine barrens generally having a higher incidence of serotiny than pitch pines of rocky outcrops or dune forests.
Environmental Description: Climate: This group is found in north temperate eastern United States and Atlantic Canada. Soil/substrate/hydrology: Substrates are of two major types: (1) deep sandy soils of outwash plains, stabilized sand dunes, and glacial till; and (2), less commonly, thin-soiled outcrops of acidic bedrock along exposed low-elevation ridgelines and upper slopes. South of Maryland, all occurrences are on acidic to mafic bedrock outcrops. The soils are in either case coarse-textured, acidic, mostly well-drained to xeric, and low in nutrients.
Geographic Range: This group occurs from Nova Scotia and southern Maine and New Hampshire south to Maryland and west to eastern Pennsylvania and New York, with outliers on higher-elevation rock outcrops in Virginia and North Carolina.
Nations: CA, US
States/Provinces: CT, DC, MA, MD, ME, NC, NH, NJ, NS, NY, ON, PA, QC, RI, VA, VT
US Forest Service Ecoregions (2007)
Domain Name:
Division Name:
Province Name: Outer Coastal Plain Mixed Forest Province
Province Code: 232    Occurrence Status: Confident or certain
Section Name: St. Lawrence and Champlain Valley Section
Section Code: 211E     Occurrence Status: Confident or certain
Omernik Ecoregions:
Plot Analysis Summary:
Confidence Level: Moderate
Confidence Level Comments:
Grank: GNR
Greasons:
Concept Lineage:
Predecessors:
Obsolete Names:
Obsolete Parents:
Synonomy: < Pinetum rigidae (Conard 1935)
> Pine barren (Forman and Boerner 1981)
> Pine barrens (Robichaud and Buell 1973)
> Pine barrens formation (Harshberger 1916)
< Pitch Pine - Virginia Pine Forest Group (Faber-Langendoen and Menard 2006) [Their group includes both this group and Virginia Pine & Table Mountain Pine Woodland & Barrens Group (G162).]
> Pitch pine - scrub oak forest (Collins and Anderson 1994)
Concept Author(s): D.S. Schweitzer and T.J. Rawinski (1988); J.W. Harshberger (1916)
Author of Description: S.C. Gawler, L.A. Sneddon and D. Faber-Langendoen
Acknowledgements: Sean Basquill
Version Date: 17Apr2013
References:
  • Bernard, J. M., and F. K. Seischab. 1995. Pitch pine (Pinus rigida Mill.) communities in northeastern New York State. American Midland Naturalist 134(2):294-306.
  • Collins, B. R., and K. H. Anderson. 1994. Plant communities of New Jersey. Rutgers University Press, New Brunswick, NJ. 287 pp.
  • Conard, H. S. 1935. The plant associations of central Long Island. The American Midland Naturalist 16:433-516.
  • Faber-Langendoen, D., and S. Menard. 2006. A key to eastern forests of the United States: Macrogroups, groups, and alliances. September 15, 2006. NatureServe, Arlington, VA.
  • Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2017a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
  • Forman, R. T. T. 1979. Pine Barrens: Ecosystems and landscape. Academy Press, New York. 601 pp.
  • Forman, R. T. T., and R. E. Boerner. 1981. Fire frequency and the pine barrens of New Jersey. Bulletin of the Torrey Botanical Club 108:34-50.
  • Gawler, S. C., and A. Cutko. 2010. Natural landscapes of Maine: A classification of vegetated natural communities and ecosystems. Maine Natural Areas Program, Department of Conservation, Augusta.
  • Harshberger, J. W. 1916. The vegetation of the New Jersey Pine Barrens. Reprinted 1970. Dover Publications, Inc., New York. 329 pp.
  • NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Central Databases. NatureServe, Arlington, VA.
  • Olsvig, L. S. 1980. A comparative study of northeastern Pine Barrens vegetation. Ph.D. dissertation, Cornell University, Ithaca, NY. 479 pp.
  • Robichaud, B., and M. F. Buell. 1973. Vegetation of New Jersey. Rutgers University Press, New Brunswick, NJ. 340 pp.
  • Schweitzer, D. S., and T. J. Rawinski. 1988. Element stewardship abstract for northeastern pitch pines / scrub oak barrens. Unpublished report. The Nature Conservancy. 21 pp.