Pond pine woodland is the name used for this community in classification systems for North Carolina (Schafale and Weakley 1990) and South Carolina, and it is synonymous with pond pine forest in those states (Nelson 1986). In Virginia's classification, pond pine woodland is a type of oligotrophic saturated or seasonally flooded woodland (Rawinski 1990). In Florida's classification, this community is a type of wet flatwoods (FNAI and FDNR 1990), and in Georgia's classification, it is a type of Coastal Plain bog/seep forest (Wharton 1978). Other names include pine swamp, pine bog, and pine pocosin (Penfound 1952).
Range/Distribution
This community occurs on the Coastal Plain from Florida to Virginia (Landaal 1991c). In North Carolina, this community is most extensive on the outer parts of the Coastal Plain (Schafale and Weakley 1990).
Environmental Factors
Topographic Position
Pond pine woodlands occur on the outer parts of domed peatlands on poorly drained interstream flats (Landaal 1991c). They also occur on shallow, peat-filled Carolina bays and swales (Schafale and Weakley 1990).
Hydrology
This community has a long hydroperiod, but the water table drops below the peat layer during the dry season, which allows plants to root below the peat (Landaal 1991c, Schafale and Weakley 1990). In North Carolina, plants in this community may also receive water with nutrients from adjacent communities. The communityoccurs in areas that are drier than low and high pocosins (Schafale and Weakley 1990).
Disturbance Regime
Fire in pond pine woodlands has been reported to occur during dry periods every 10 to 20 years (Landaal 1991c). However, historical reports going back to the times of the colonists describe the fire interval as 3 to 5 years (Hughes 1966), and even poorly drained areas have seldom burned less frequently than every 5 years (Wells 1942). Frost (1989) describes a fire regime of 3 to 5 years as ideal for the continuation of a pure canebrake understory that was once common. Fire regimes of 5 to 18 years result in alternation of cane understory and pocosin shrub understory on peat from 0.5 to 1 m deep (Frost 1989). Because of their drier position on the landscape, pond pine woodlands burn more frequently than low and high pocosins. Fires can be intense due to the buildup of large amounts of fuel between fires (Schafale and Weakley 1990). Pond pine is a good example of a fire adapted species. It is able to sprout from either the roots or epicormic buds along the bole, producing the gnarled form of growth exhibited by the species. Its cones, remaining closed from 2 to 10 years after seed maturation, open upon being burned, although they do eventually open in the absence of fire (Ash et al. 1983). Switch cane, which once dominated these understories, requires a fire regime of about 10 years or less to be maintained (Hughes 1966). Fires in this community are most likely to occur during the growing season. However, in recent decades, most fires have occurred during April and May. Because of the heavy fuel loads, fires in pond pine woodland have the potential to be extremely intense. Like the recovery of the pines themselves, shrub vegetation generally recovers to its former height in a few years. Fire may burn through the peat as it kills much or all of the above-ground vegetation. Fires may change the relative species composition, favoring those that recover first, such as cane. Species diversity is highest after a fire event and gradually declines thereafter (NCNHP and TNC 1995).
Soil
This community occurs on acidic, shallow, organic soils or on deeper peats. Most Florida sites have an organic hardpan or clay layer beneath the surface (Landaal 1991c). They are presumably less nutrient deficient than low and high pocosins because of the mineral influx brought in by sheetflow (NCNHP and TNC 1995). Increases in the amount of silt and clay are correlated with an increased site index for pond pine (Coile 1952). Site indices of pond pine increase with the decreasing organic matter content of the A1 horizon (Hofman 1949, Zahner 1951).
Physiognomy/Structure
Canopy density can vary from very dense to savanna-like with scattered pines and palms over a grassy understory (Landaal 1991c). The shrub layer is dense and tall (over 5 m) except immediately following fire. The shrub layer may be lost if the fire interval is too short. If fire consistently occurs more often than every 5 years, cane (Arundinaria gigantea or A. tecta) can dominate the understory. Cane dominated the understory of pond pine woodlands over vast areas in the past, but rarely do today (Hughes 1966, Fussel et al. 1995). The density of cane seems to be controlled primarily by fire regime, with minor secondary effects of organic soil depth and fertility. With fire regimes of 3 to 5 years, pure cane may be maintained; however, fire regimes of 5 to 18 years result in alternation between pure cane, immediately following fire, and pocosin shrub with occasional stems of cane concealed by the shrub canopy. Besides occasional pond pines there may co-exist some blaspheme vine (Smilax laurifolia), poison ivy (Rhus toxicodendron) or dewberry (Rubus hispidus) (Frost 1989). The herb layer is generally sparse (Schafale and Weakley 1990).
Commonly Associated Plant Communities
Plant communities closely associated with pond pine woodlands are other pocosin types, non-riverine swamp forests, pine flatwoods (Landaal 1991c), and pine savannas (Schafale and Weakley 1990). Ponds may occur as inclusions into pond pine woodlands where the peat has been burned down to the mineral soil (Landaal 1991c).
Successional Relationships
This community is early successional and usually replaces itself following fire. In the absence of fire, this community will be encroached upon by bays in the understory and succeed to a bay forest (Landaal 1991c). When fire frequency was much higher, large areas of this habitat were dominated by cane in canebrakes. Increased fire frequency may lead to a cane-dominated understory.
Biological Composition
Pond pine (Pinus serotina) forms an open to nearly closed canopy. Within its range, loblolly bay (Gordonia lasianthus) is a canopy co-dominant with pond pine. Sweetbay (Magnolia virginiana), red maple (Acer rubrum), loblolly pine (Pinus taeda) and AWC may also occur in the canopy or the understory (Landaal 1991c, Schafale and Weakley 1990). The subcanopy or shrub layer is dominated by titi (Cyrilla racemiflora), fetter-bush (Lyonia lucida), sweet gallberry (Ilex coriacea), and swamp red bay (Persea palustris) (Landaal 1991c). Common vines are blaspheme vine and coral greenbriar (Smilax walteri) (Landaal 1991c). Herbs are generally nearly absent, but may include Virginia chainfern (Woodwardia virginica), netted chainfern (Woodwardia areolata), and peat moss (Sphagnum sp.) clumps (Landaal 1991c, Schafale and Weakley 1990). Switch cane once dominated large areas of the herb layer of this habitat, although it is uncommon today (probably because of suppression of fire, Schafale and Weakley 1990).