KUCHLER TYPE
KUCHLER TYPE: Pocosin



KUCHLER-TYPE-NUMBER : 
K114

PHYSIOGNOMY : 
Low open forests of needleleaf evergreen trees and broadleaf evergreen
low trees and shrubs and much moss.


OCCURRENCE : 
The pocosin Kuchler type extends from the coastal plains of Virginia to
South Carolina [8].  A recent survey shows pocosins extending from
Virgina to northern Florida. Under this survey pocosins were broadly
defined shrub and forest bogs, Atlantic white-cedar (Chamaecyperis
thyoides) stands, and some loblolly pine (Pinus taeda) stands on flooded
soils [13].  This report uses Kuchler's more restrictive definition
given in PHYSIOGNOMY.  Upland communities and those with less peaty
soils are considered as K111 (oak-hickory-pine forest), K112 (southern
mixed forest), and K113 (southern floodplain forest) and are not
discussed here.


COMPILED BY AND DATE : 
S. A. Snyder, December 1993


LAST REVISED BY AND DATE : 
NO-ENTRY


AUTHORSHIP AND CITATION : 
Snyder, S. A. 1993. Pocosin. In: Remainder of Citation


Kuchler Type Index
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KUCHLER TYPE DESCRIPTION


PHYSIOGRAPHY : 
Pocosins occur on low flatlands along or near the coast and are
characterized by broad, shallow stream basins [14].


CLIMATE : 
Average rainfall for the coastal region is 48.5 inches (1,230 mm)
annually.  July and August are typically the wettest months.
Evaporation usually exceeds rainfall in June and about equals rainfall
in July and August [13].


SOILS : 
Pocosins occur on highly organic or peaty soils with prolonged
inundation and poor drainage.  Peat depths can range from 24 inches to
more than 60 inches (60 to>150 cm). As many as 40 different soils are
found under the pocosin community.  The organic mucks and peats
characteristic of pocosins contain or are underlain by layered marine
sediments varying in texture from clay to sand.  The organic horizon has
a pH of 3.5 to 4.1, while mineral soils are only slightly less acidic.
The soil's organic layer can be as deep as 16 inches (40 cm) [14].
Pocosin soils are nutrient deficient, especially in phosphorus [19].
Physical and chemical soil properties for pocosins have been listed
[13].


VEGETATION : 
Typically pocosins are shrub bogs with only scattered stems of pond pine
(Pinus serotina) and occasionally loblolly pine (P. taeda) or longleaf
pine (P. palustris) [14].  Pond pine and inkberry (Ilex glabra) are
listed as dominant overstory species [8].  Shrub cover is usually 1.5 to
13 feet (0.5-4 m) high.  "Short pocosins" are classified as those with
trees less than 20 feet (6 m) high.  "Tall pocosins" are characterized
by trees over 20 feet (6 m) high.  Species that are common on
better-drained sites include loblolly and longleaf pines, sweet
pepperbush (Clethra alnifolia), fetterbush (Lyonia lucida), zenobia
(Zenobia pulverulenta), and blueberry (Vaccinium spp.).  Species found
on less peaty sites include sweetbay (Magnolia virginiana),
loblolly-bay (Gordonia lasianthus), and red maple (Acer rubrum) [14].
Other species of pocosins include titi (Cyrilla racemiflora), wax myrtle
(Myrica cerifera), redbay (Persea borbonia), greenbrier (Smilax
laurifolia), moss (Sphagnum spp.), baldcypress (Taxodium spp.), tupelo
(Nyssa spp.), and Atlantic white-cedar [8,14].

Endangered plants include white wicky (Kalmia cuneata), arrowleaf
shieldwort (Paltandra sagittae-folia), spring flowering goldenrod
(Solidago verna), rough-leaf loosestrife (Lysimachia asperulaefolia),
and white beadrush (Rynchospora alba).  Threatened plants include Venus
flytrap (Dionaea muscipula), dwarf fothergilla (Fothergilla gardenii),
and sweet pitcher-plant (Sarracenia rubra) [13].


WILDLIFE : 
Research concerning pocosin fauna and the importance of pocosin habitat
has been very limited, but many species have been recorded [13].  These
include many reptiles and amphibians, rodents, black bear, bobcat, fox,
bats, white-tailed deer, opossum, raccoon, river otter, mink, muskrat,
northern bobwhite, American woodcock, and several species of fish
[4,13,14].


ECOLOGICAL RELATIONSHIPS : 
Pocosins are highly efficient at storing and regulating fresh water,
which may contribute to regional ecosystem stability [13].  The
thickness of the peat layer, hydroperiod length, and frequency and
severity of fire all control the distribution and composition of pocosin
vegetation.  Typically pocosins occur where the water table is at or
near the surface for 6 to 12 months per year [14]. High
evapotranspiration rates in summer can lower the water table to 24 to
35.5 inches (60-90 cm) below the surface.  Short pocosins occur on deep
peats (>3 feet [1 m]) that are nutrient deficient. Tall pocosins usually
occur on shallow peats (20-40 inches [50-100 cm]) with a higher nutrient
content and have greater biomass production.  With a decrease in peat
depth and inundation pocosins become pine flatwoods [13].

Two pocosin communities have been identified in the Green Swamp, North
Carolina.  The suitability of the classification has not been determined
outside of the Green Swamp, but this remains one of the most
comprehensive classifications to date.  The first class is pine and
heath shrub (pond pine/titi-zenobia), which develops on deep to
intermediate organic soils with long hydroperiods and frequent fire.
The second class is conifer-hardwood (pond pine-red maple-swamp tupelo
[Nyssa sylvatica]/titi-fetterbush), which develops on shallow organic
soils with shorter hydroperiods. No fire frequencies for this class are
discribed [14].

There is a tendency for titi to dominate pocosin sites in northeastern and
central North Carolina and fetterbush to dominate sites further south.
Zenobia dominates sites in both these areas following fire, especially
where productivity is low and species diversity is high [14].

Pocosins have complex successional trends owing to the interactions of
nutrient availability, hydroperiod, and fire.  It is possible that
pocosins were initially marsh vegetation dominated by grasses and
aquatic macrophytes, and succeeded to Atlantic white-cedar and
baldcypress.  Pocosins expanded with peat accumulation and the rise of
the water table.  Fires set by Native Americans and then white settlers
may have expanded pocosins [14].  A discussion of successional trends
related to fire, as summarized in the literature, follows.

Titi, inkberry, and fetterbush often dominate unburned pocosins [2].
Without fire Atlantic white-cedar communities succeed to titi, redbay,
and sweetbay [12].  Pocosins may eventually succeed to swamp forest
dominated by swamp tupelo, sweetgum (Liquidambar styraciflua) and red
maple if the process is not impeded by deep peat [14].

Low-intensity fires usually change pocosin species composition very
little [13].  Inkberry-titi-zenobia communities are maintained by
frequent fire [12].  Frequent fire can also maintain pond pine stands,
but frequent fire during the dry season may completely eliminate pond
pine and establish a grass-sedge bog or savannah [1].

Severe fires may reduce peat depth, converting short pocosins to marshes
[13].  In Atlantic white-cedar, sweetbay, redbay, or baldcypress-tupelo
communities, severe fires are usually followed by stands of inkberry,
titi, and zenobia [12].  Pond pine usually succeeds Atlantic white-cedar
following fire if a seed source is present, although cedar may
eventually establish also [1].  Blueberry, zenobia, and wicky (Kalmia
carolina) occassionally dominate severely burned sites.  Herbs that can
appear following fire include chain fern (Woodwardia virginica),
Osmunda spp., bracken fern (Pteridium aquilinum), sedge (Carex
walteriana), Lachnanthes caroliniana, meadow beauties (Rhexia spp.), and
pitcher-plant (Sarracenia spp.) [2].

For more information on community dynamics in pocosin types refer to
Christensen [21].  For detailed information on pocosin dynamics refer to
Richardson and Gibbons [22].

KUCHLER TYPE VALUE AND USE
KUCHLER TYPE: Pocosin



FORESTRY VALUES : 
Some pocosins are managed for wood products [13,14].


RANGE VALUES : 
Pocosins are drained to create range for cattle [14].


WILDLIFE VALUES : 
Pocosins are considered regionally critical habitat because they are
usually the only natural areas left for wildlife.  No species of plants
or animals are unique to pocosins, but these types may serve as key
habitats for certain faunal communities.  Some wildlife that use
pocosins and that have federal or state protection status include the
swallowtail and Hessel's hairstreak butterflies, the pine barrens tree
frog, the eastern diamondback rattlesnake, and the American alligator
[13].  Pocosins provide some habitat for the endangered red-cockaded
woodpecker [7,13].


OTHER VALUES : 
Pocosins have been drained to grow crops like soybeans and corn [13].
Peat is mined from pocosins [13,14].


MANAGEMENT CONCERNS : 
For longterm biodiversity and ecosystem stability, pocosin management
should be based on maintaining the natural hydrological regime.  Loss of
wetlands in the Southeast (of which pocosins are an important part)
occurs at a rate of 156,000 hectares per year.  About half the area in
pocosin communities is owned by corporate agriculture and timber
companies.  To grow crops or trees, pocosins are drained and much of the
natural vegetation completely removed.  Soils are often altered to
prepare for forestry or agriculture, significantly changing the natural
ecological processes of pocosins [13].  Peat mining requires drying out
the surface peat, which increases the probability of severe fire.  Peat
mining may also cause land subsidence, followed by saltwater intrusion
[14].

For detailed information on pocosin management not related to fire refer
to Ash and others [20] and Richardson [22].

KUCHLER TYPE FIRE ECOLOGY AND MANAGEMENT
KUCHLER TYPE: Pocosin



FUELS, FLAMMABILITY, AND FIRE OCCURRENCE : 
Lowering of the water table for agriculture and silviculture has
increased the frequency of dry periods and, therefore, increased fire
frequency [2].  Fires once per decade may cause the deciduous overstory
to be replaced by pond pine with a cane (Arundinaria spp.) understory.
More frequent fires promote shrubs and shrubby trees such as sweetbay,
redbay, dog-laurel (Leucothe spp.), and greenbrier.  Annual fires
eliminate shrubs and create savannahs of grasses, sedges (Carex spp.),
and herbs [17].

Pocosins have highly combustible fuels and deep, peaty soils.  Fires can
"blowup" in the volatile evergreen vegetation, especially where needle
drape provides continuity of ladder fuels [16].  Fires can be severe in
peaty soils; severity may be related to depth of water table at the time
of burning [14].
 
Commonly, weights of fine fuels in pocosins of North Carolina are 15
tons per acre.  Under extreme drought this figure can double when peats
dry out to depths of 1 to 2 feet (0.3-0.6 m) [16].  Pocosin fuels have
been classified based on species composition, height, and density.  A
key is available for identifying fuel types.  Each type is described in
terms of total weight and potential fire behavior.  Blowup potential in
open, low pocosin is rated as low; in dense, low pocosin as medium; in
high pocosin as medium-high [18].


FIRE EFFECTS ON SITE : 
When fires burn the peat layer down to the water table they can create
small lakes in shallow burned-out depressions [2].

Nutrient availability following fires in oligotrophic ecosystems of the
Southeast, including pocosins, has been examined [3,6].  Detailed lists
of available nutrients and soil physical properties following prescribed
burning in the Coastal Plain of South Carolina are available [11].
Burns in peat soils have been shown to enhance nutrient availability and
increase plant production.  However, nutrient levels usually return to prefire
conditions during the second postfire growing season [19].


FIRE EFFECTS ON VEGETATION : 
Pocosin fires are usually intense, consuming most or all of the
aboveground biomass [2].  These fires do not usually kill plant roots.
Sprouting shrubs include loblolly-bay, gallberry (Ilex spp.), redbay,
fetterbush, and titi.  Pond pine is also fire-adapted, sprouting from
the bole and branches following fire.  Young pond pine also sprout from
the root crown.  If roots are killed, sprouting will not occur, but a
seedbed will be prepared for pond pine seeds from serotinous cones [18].

A severe wildfire in late March burned 29,300 acres (11,860 ha) of
pocosins and related communities in coastal North Carolina.  At times
fireline intensity averaged 18,000 Btu/sec/foot.  More than 20,000 acres
(9,000 ha) of pond pine were defoliated.  Following this fire, a lower
than expected percentage of 13-year-old pond pine sprouted from the bole
because of the high intensity of the fire, but many trees sprouted from
the root crown.  No quantitative information on survival or sprouting
was available [16].

An early May fire in a South Carolina pocosin was prescribed to promote
natural regeneration of pond pine, remove the understory, and reduce the
fire hazard.  The fire was considered "successful."  Estimated pond pine
mortality was only 3 percent.  Eight weeks following the fire an average
of 8,000 seedlings per acre was present [15].

The effects of fire after 20 years of experimental burning in the pine
forests of the Coastal Plain were examined.  There was no specific
reference to pocosins, but it is possible that pockets of pocosin
communites were included.  Plots were burned annually in summer,
annually in winter, periodically in summer, periodically in winter, and
biennially in summer.  Plots burned annually in summer showed the
smallest amount of woody cover, while the greatest amount was on plots
burned periodically.  Inkberry showed significant (p<5%) decreases when
burned annually in winter compared with unburned and periodically burned
plots [10].

Atlantic white-cedar needs disturbance like fire to establish, but
severe fires may consume the peat layer, killing seeds.  Quickly moving,
low intensity fires may not reduce competition from other vegetation
sufficiently to allow cedar to establish.  Once established Atlantic
white-cedar persists only in the absence of fire [4].


FIRE EFFECTS ON RESOURCE MANAGEMENT : 
Fire can set back timber harvest in some areas [16].  Prescribed fire
may be beneficial to red-cockaded woodpeckers by releasing loblolly pine
stands [7].  Inkberry produces valuable food for wildlife.  Its fruit
production may drop in the first postfire years, but peaks 3 years
following fire [9].


FIRE USE CONSIDERATIONS : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Because of the high flammability of pocosins, frequent prescribed burns
are recommended to reduce fire hazard [16].  Nine guidelines for
prescribed burning in pocosins have been listed [15].


REHABILITATION OF SITES FOLLOWING WILDFIRE : 
NO-ENTRY

References for Kuchler: [K114]

1. Bramlett, David L. 1990. Pinus serotina Michx. pond pine. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 470-475. [13407]

2. Christensen, Norman L. 1981. Fire regimes in southeastern ecosystems. In: Mooney, H. A.; Bonnicksen, T. M.; Christensen, N. L.; [and others], technical coordinators. Fire regimes and ecosystem properties: Proceedings of the conference; 1978 December 11-15; Honolulu, HI. Gen. Tech. Rep. WO-26. Washington, DC: U.S. Department of Agriculture, Forest Service: 112-136. [4391]

3. Christensen, Norman L. 1987. The biogeochemical consequences of fire and their effects on the vegetation of the Coastal Plain of the southeastern United States. In: Trabaud, L., ed. The role of fire in ecological systems. Hague, The Netherlands: SPB Academic Publishing: 1-21. [17285]

4. Clark, Mary K.; Lee, David S.; Funderburg, John B., Jr. 1985. The mammal fauna of Carolina bays, pocosins, and associated communities in North Carolina: an overview. Brimleyana. 11: 1-38. [13478]

5. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]

6. Gilliam, Frank S. 1991. The significance of fire in an oligotrophic forest ecosystem. In: Nodvin, Stephen C.; Waldrop, Thomas A., eds. Fire and the environment: ecological and cultural perspectives: Proceedings of an international symposium; 1990 March 20-24; Knoxville, TN. Gen. Tech. Rep. SE-69. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station: 113-122. [16641]

7. Hooper, Robert G.; Krusac, Dennis L.; Carlson, Danny L. 1991. An increase in a population of red-cockaded woodpckers. Wildlife Society Bulletin. 19(3): 277-286. [18029]

8. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]

9. Landers, J. Larry. 1987. Prescribed burning for managing wildlife in southeastern pine forests. In: Dickson, James G.; Maughan, O. Eugene, eds. Managing southern forests for wildlife and fish: a proceedings; [Date of conference unknown]; [Location of conference unknown]. Gen. Tech. Rep. SO-65. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station: 19-27. [11562]

10. Lewis, Clifford E.; Harshbarger, Thomas J. 1976. Shrub and herbaceous vegetation after 20 years of prescribed burning in the South Carolina coastal plain. Journal of Range Management. 29(1): 13-18. [7621]

11. McKee, William H. 1982. Changes in soil fertility following prescribed burning on Coastal Plain pine sites. Res. Pap. SE-234. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 23 p. [11854]

12. Penfound, William T. 1952. Southern swamps and marshes. The Botanical Review. 18: 413-446. [11477]

13. Richardson, Curtis J.; Gibbons, J. Whitfield. 1993. Pocosins, Carolina bays, and mountain bogs. In: Martin, William H.; Boyce, Stephen G.; Echternacht, Arthur C., eds. Biodiversity of the southeastern United States: Lowland terrestrial communities. New York: John Wiley & Sons, Inc: 257-311. [22013]

14. Sharitz, Rebecca R.; Gibbons, J. Whitfield. 1982. The ecology of southeastern shrub bogs (pocosins) and Carolina bays: a community profile. FWS/OBS-82/04. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service, Division of Biological Services. 93 p. [17015]

15. Taylor, D. F.; Wendel, G. W. 1964. Stamper Tract prescribed burn. Res. Pap. SE-14. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 12 p. [15806]

16. Wade, Dale D.; Ward, Darold E. 1973. An analysis of the Air Force Bomb Range Fire. Res. Pap. SE-105. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest and Range Experiment Station. 38 p. [20751]

17. Wells, B. W.; Whitford, L. A. 1976. History of stream-head swamp forests, pocosins, and savannahs in the Southeast. Journal of the Elisha Mitchell Science Society. 92: 148-150. [19501]

18. Wendel, G. W.; Storey, T. G.; Byram, G. M. 1962. Forest fuels on organic and associated soils in the coastal plain of North Carolina. Station Paper No. 144. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 46 p. [21669]

19. Wilbur, Rebecca B.; Christensen, Norman L. 1983. Effects of fire on nutrient availability in a North Carolina coastal plain Pocosin. The American Midland Naturalist. 110(1): 54-61. [11594]

20. Ash, A. N.; McDonald, C. B.; Kane, E. S.; Pories, C. A. 1983. Natural and modified pocosins: literature synthesis and management options. FWS/OBS-83/04. Washington, DC: U.S. Fish and Wildlife Service, Division of Biological Sciences. 156 p. [16178]

21. Christensen, Norman L. 1988. Vegetation of the southeastern Coastal Plain. In: Barbour, Michael G.; Billings, William Dwight, eds. North American terrestrial vegetation. Cambridge: Cambridge University Press: 317-363. [17414]

22. Richardson, Curtis J.; Gibbons, J. Whitfield. 1993. Pocosins, Carolina bays, and mountain bogs. In: Martin, William H.; Boyce, Stephen G.; Echternacht, Arthur C., eds. Biodiversity of the southeastern United States: Lowland terrestrial communities. New York: John Wiley & Sons, Inc: 257-311. [22013]

Related categories for Kuchler Type: Pocosin