Natural Community Systems -- Photo Guide

Pitch pine sand plain system

trail through pitch pine sand plain system in the Ossipee region (photo by Ben Kimball for the NH Natural Heritage Bureau)
trail through pitch pine sand plain system in the Ossipee region
(photo by Ben Kimball for the NH Natural Heritage Bureau)

pitch pine sand plain system (photo by Ben Kimball for the NH Natural Heritage Bureau)
pitch pine sand plain system (photo by Ben Kimball)

 

Description: This system occurs primarily on droughty, excessively well drained soils in central and southern New Hampshire and is most well developed on the extensive sand plain areas of the Ossipee and lower Merrimack Valley regions.  These areas are characterized by a frequent historic fire regime and indicated by Pinus rigida (pitch pine), Quercus ilicifolia (scrub oak), other fire-maintained plant species, and numerous Lepidoptera (butterflies and moths) that are obligates to these plants.  The central natural community, pitch pine - scrub oak woodland, forms a discontinuous canopy with dense shrub stratums of scrub oak and low heaths. 

Several successional and disturbance-related expressions can be present including scrub oak thickets, pockets of pitch pine forest, grassy openings, and heath barrens.  Fire is important for maintaining community structure, dynamics, and composition (floristic and faunal).  Pitch pine - scrub oak woodlands require fire return intervals of at most 50100 years to maintain community composition.  Logging history also influences canopy structure, and in combination with fire history, explains much of the compositional variation seen in this system.  Other natural communities are characteristic in the larger mosaic, particularly in portions of the sand plain that have had less frequent fire return intervals (i.e., areas more isolated from the most frequently burned areas) or those that occur on somewhat more mesic sandy soils (i.e., those adjacent to rivers or wetlands).

Diagnostic natural communities:

      • Pitch pine - scrub oak woodland (S1S2)

Primarily found in the Ossipee region

      • Mixed pine - red oak woodland (S1)

      • Red pine - white pine forest (S3)

Primarily found in the Merrimack Valley and coastal regions

      • Pitch pine - Appalachian oak - heath forest (S1)

Peripheral or occasional natural communities:

      • Dry red oak - white pine forest (S3S4)

      • Dry Appalachian oak forest (S1S3)

      • Dry river bluff (S2)


Landscape settings: lowland, valley bottom settings with extensive sand and gravel deposits derived from glacio-fluvial meltwaters [outwash plains, ice-contact features (eskers, kames), and ancient river deltas and terraces]

Soils:
Excessively well drained sands and gravels with modest duff accumulation due to frequent fire

Spatial pattern: small to large patches (101,000 acres)

Physiognomy: woodlands with tall shrub, dwarf shrub, and graminoid dominated openings; successional to forest in the absence of fire

Distribution: central and southern NH


Characteristic species:

Frequent species of the pitch pine - scrub oak woodland:

Primarily sand plain species:
   Pinus rigida (pitch pine)
   Quercus ilicifolia (scrub oak)
   Ceanothus americanus (eastern New Jersey tea)
   Quercus prinoides (dwarf chestnut oak)
   Oryzopsis pungens (slender mountain rice-grass)
   Lespedeza capitata (round headed bush-clover)
   Leptoloma cognatum (fall witch-grass)
   Lechea spp. (pinweeds)
   Helianthemum canadense (Canadian frostweed)
   Aster linariifolius (stiff-leaved aster)
   Carex tonsa (shaved sedge)
   Hudsonia ericoides (golden-heather)
   Liatris borealis (northern blazing star)
   Lupinus perennis (wild lupine)
   Asclepias amplexicaulis (blunt-leaved milkweed)
   Cyperus lupulinus (perennial umbrella-sedge)

Other common to occasional species:
   Vaccinium angustifolium (lowbush blueberry)
   Vaccinium pallidum (hillside blueberry)
   Apocynum androsaemifolium (spreading dogbane)
   Carex lucorum (distant sedge)
   Comandra umbellata (bastard toad-flax)
   Oryzopsis asperifolia (rough-leaved rice-grass)
   Schizachyrium scoparium (little bluestem)
   Pteridium aquilinum (bracken fern)  
   Comptonia peregrina (sweet fern)
   Pinus strobus (white pine)
   Betula populifolia (gray birch)
   Quercus rubra (red oak)
   Quercus velutina (black oak)


Associated natural community systems: This system is commonly punctuated by open peatland systems where sand plains intersect the water table. Kettle hole bog systems, poor level fen/bog systems, and medium level fen systems are most common in these landscapes. In central NH, pitch pine sand plain systems transition to hemlock - hardwood - pine forest system on adjacent sand plain or till settings with no (or a less frequent) fire history. In southern New Hampshire it transitions to Appalachian oak - pine forest systems on till or sand plain settings with less frequent fire histories.



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