_____________

The Author:

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Martha R. McKevlin, Plant Physiologist, Southern Research Station,

U.S. Department of Agriculture, Forest Service, Charleston, SC 29414.

Preface

Old growth is widely acknowledged today as an essential part of managed forests, particularly on public lands. However, this

concept is relatively new, evolving since the 1970's when a grassroots movement in the Pacific Northwest began in earnest to

define old growth. In response to changes in public attitude, the U.S. Department of Agriculture, Forest Service began

reevaluating its policy regarding old-growth forests in the 1980's. Indeed, the ecological significance of old growth and its

contribution to biodiversity were apparent. It was also evident that definitions were needed to adequately assess and manage the

old-growth resource. However, definitions of old growth varied widely among scientists. To address this discrepancy and other

old-growth issues, the National Old-Growth Task Group was formed in 1988. At the recommendation of this committee, old

growth was officially recognized as a distinct resource by the Forest Service, greatly enhancing its status in forest management

planning. The committee devised "The Generic Definition and Description of Old-Growth Forests" to serve as a basis for

further work and to ensure uniformity between Forest Service Stations and Regions. Emphasis was placed on the quantification

of old-growth attributes.

At the urging of the Chief of the Forest Service, all Forest Service Stations and Regions began developing old-growth

definitions for specific forest types. Because the Southern and Eastern Regions share many forest communities (together they

encompass the entire Eastern United States), their efforts were combined, and a cooperative agreement was established with

The Nature Conservancy for technical support. The resulting project represents the first large-scale effort to define old growth

for all forests in the Eastern United States. This project helped bring the old-growth issue to public attention in the East.

Definitions will first be developed for broad forest types and based mainly on published information and so must be viewed

accordingly. Refinements will be made by the Forest Service as new information becomes available. This document represents

1 of 35 forest types for which old-growth definitions will be drafted.

In preparing individual old-growth definitions, authors followed National Old-Growth Task Group guidelines, which differ

from the standard General Technical Report format in two ways—the abstract (missing in this report) and the literature

citations (listed in Southern Journal of Applied Forestry style). Allowing for these deviations will ensure consistency across

organizational and geographic boundaries.

September 1996

Southern Research Station

P.O. Box 2680

Asheville, NC 28802
An Old-Growth Definition for Evergreen Bay

Forests and Related Seral Communities

Martha R. McKevlin

Introduction

Forests of the North American continent consist of diverse

associations of woody and herbaceous plants. Within these

forests, many species tend to occur as typical of various

physiographic regions and topographic features.

Historically, these communities have been viewed as

pioneer, seral, or climax, relative to their persistence within

the ecosystem. The popularized view of old-growth forests

has been one of the plant communities in a climax

equilibrium with individual trees hundreds of years old

comprising most of the population of the dominant species.

In cases where natural disturbances were rare or of limited

intensity, community succession could proceed to its

climactic condition and dominant individuals of long-lived

species could attain ages of 500 to 1,000 years, such as

occurs in the Douglas-fir forests of the Pacific Northwest.

Sprugel (1991) refers to this concept as the “natural”

ecosystem, which has been adhered to by many early

ecologists. However, current views of community ecology

suggest that nonequilibrium in plant communities is more

common than not and that most natural ecosystems are

dynamic, even in the absence of human activity (Davis

1984, Brubaker 1988, Sprugel 1991). Frequent and/or

catastrophic disturbances, such as fire, can prevent plant

communities from attaining a climax equilibrium and the

associated characteristics considered common to old

growth. Disturbances and changes in climate can influence

species disproportionately, altering common community

associations according to responses of the individual.

Considering the current focus within the U.S. Department

of Agriculture, Forest Service on managing for healthy,

sustainable forest ecosystems, more information is needed

on the temporal dynamics of the many forest cover types

found in the United States. In other words, what

characteristics, other than age of specific individuals, make

a forest ecosystem old? Pioneer and seral communities can

persist over long periods provided that perturbations

necessary to their initiation are frequent. Root stocks,

rhizomes, and, in some cases, seed banks can be relatively

old, although the aboveground shoots arising from these

components may not themselves be old. Can these

communities be considered ancient or old growth even if the

longevity of the individuals is limited? What constitutes “old

growth” in community types that may not ever achieve a

climax equilibrium and are subject to frequent, natural

disturbances? Should these systems be excluded from the

consideration given to more traditional old-growth forests?

Definitions including such systems should be developed so

that the natural dynamics of the ecosystem as a whole can be

sustained, not simply the existing collection of individuals.

Narrative Description

The bay forest type (41) falls under Disturbance Class 3 of

the composite list prepared by the National Old-Growth Task

Group; forests with infrequent, high intensity, widespread

disturbances and the subcategory, palustrine forests. This

forest type is similar to the Society of American Foresters

forest type 84, slash pine; 85, slash pine-hardwood; and 104,

sweetbay-swamp tupelo-redbay. A previously prepared

narrative description of the forest type is as follows: “Bay

forests occur exclusively in the Coastal Plain physiographic

province, and range from Maryland to southeast Texas.

These forests are restricted to coastal depressions or

floodplains where saturated conditions prevail. Soils usually

are organic, although mineral soils do occur in floodplains.

Most are highly acidic and low in nutrient availability.

Surface flooding is common, but usually is not persistent.

“In addition to loblolly bay (Gordonia lasianthus), sweet bay

(Magnolia virginiana), and red bay (Persea borbonia),

common species include swamp tupelo (Nyssa sylvatica var.

biflora), sweetgum (Liqidambar styraciflua), red maple

(Acer rubrum), slash pine (Pinus elliottii), pond pine (P.

serotina), live oak (Quercus virginiana), bald cypress

(Taxodium distichum), pond cypress (T. ascendens), and

Atlantic white cedar (Chamaecyparis thyoides). Hydric

conditions retard the invasion by flood-sensitive species and

consequent succession to other forest types. Disturbance

from fire and storm events plays an important role in the
2

ecological development of these systems. This forest type successional stage to the evergreen bay forest and are the

frequently reverts to Atlantic white cedar or pond pine result of fire disturbance within the past 10 to 20 years

forests (forest types 40 and 29, respectively) after (Buell 1946, Duever et al. 1982). The shrub species found in

catastrophic fires.” shrub bogs often occur as understory in bay forests and

The term “bay,” used in this document, has a dual meaning. loblolly-bay [Gordonia lasianthus (L.) Ellis], and redbay

It refers to both a kind of site, e.g., Carolina bay, and a [Persea borbonia (L.) Spreng.] often occur in shrub bogs

general grouping of tree species that may inhabit that site, (Richardson and Gibbons 1993). However, Otte (1981) and

e.g., bay trees. Christensen et al. (1981) have different views on the

Occurrence

Bay forests occur in several physiographic provinces with

different geologic origins and topographic features.

However, bay forests are considered rare and are found in

scattered patches, often in a mosaic with other forest types

in various stages of succession (Schafale and Harcombe

1983, Abrahamson and others 1984, Bennett and Nelson

1991). Pocosins, Carolina bays and sandhill seeps, stream

heads, and stream margins will often support this forest type

(Wells 1928, Monk 1966, Waggoner 1975, Christensen et

al. 1981, Nelson 1986).

Pocosins

Pocosins occur on low, coastal-plain terraces of Virginia

and the Carolinas. These physiographic features are

nonalluvial, occurring on divides between rivers, in broad,

shallow stream basins, drainage-basin heads, and on broad,

flat uplands (Wells 1928, Kologiski 1977). Common

synonyms for pocosin and pocosin-like areas include bay,

bayland, bayhead, baygall, xeric shrub bog, and evergreen

shrub bog (Kologiski 1977, Sharitz and Gibbons 1982,

Schafale and Harcombe 1983). Pocosins have shallow to

deep organic soils of sandy humus, muck, or peat and

intermediate to long hydroperiods with temporary surface

water (Kologiski 1977). Soils reported for North Carolina

pocosins include Dare, Dorovan, Pamlico, and Ponzer

(Kologiski 1977).

Pocosins are often further described as being either tall or

short, depending on the average height of the canopy

dominants, which can be up to 32.8 feet [10 meters (m)]

(Christensen et al. 1981). Bay forests are more closely

associated with tall pocosins; evergreen shrub bogs are

associated with short pocosins. Kologiski (1977) described

the bay forest canopy as only 9.84- to 32.8-feet (3- to 10-m)

high with the shrub stratum blending into the canopy layer.

Greater fertility and productivity are also generally

characteristic of tall pocosins and bay forests (Christensen

et al. 1981, Richardson and Gibbons 1993). Evergreen

shrub bogs are believed by some to represent an earlier

stunted individuals of sweetbay (Magnolia virginana L.),

successional relationships between shrub bogs and bay

forests.

Carolina Bays

Carolina bays are floristically similar to many pocosin sites

and may also support evergreen bay forests (Buell 1946,

Porcher 1966, Sharitz and Gibbons 1982, Bennett and

Nelson 1991), although, when present in Carolina bays,

sweetbay and redbay most often occur as shrubs (Schalles et

al. 1989). The general term “bay” refers to the dense growth

of bay trees found on many upland sites having histic soils

with poor drainage; Carolina bays are the most abundant of

these types of sites in the Southeast (Schalles 1979).

Carolina bays are unusual topographic features common to

the Atlantic Coastal Plain. They are natural, elliptical

depressions oriented northwest to southeast often having a

pronounced sand rim along the southeastern edge. These

depressions are isolated wetlands with no natural drainage

outlets and are usually ombrotrophic. Typically, the central

zone of a Carolina bay remains more or less inundated,

depending upon weather patterns and local hydrology

(Bennett and Nelson 1991). This perched, surface water is

maintained by an impervious clay lens or a sand-ironhumate complex (Schalles 1979). Soil types within Carolina

bays may vary but are usually composed of an organic

surface layer of peat varying in depth and underlain by a

layer of sand, which usually forms part of the impervious

humate complex. However, clay-based bays generally have a

mineral soil overlying the clay layer with little or no peat

accumulation in the basin (Bennett and Nelson 1991). Bay

forests are generally peat-based as opposed to clay-based.

Sandhill Seeps and Drainages

Sandhill seeps are found in the upper Atlantic Coastal Plain.

They are usually located at the bases of hills and ridges in

depressions where there is groundwater seepage from the

adjacent slopes. The soils are histic due to constant

saturation, although the seeps are seldom flooded. Stream

margins and heads of stream branches along the Gulf 

Coastal Plain may also develop peaty soils and support bay
3

forests (Monk 1966). These bayheads are visually Hamilton 1984). However, there is disagreement on the

distinguishable from cypress ponds by the absence of direction and driving forces of succession. Wells (1928)

cypress trees and standing water, and the presence of an suggested that the pocosin or shrub bog was a seral stage

irregular surface with exposed, highly convoluted roots within a successional sequence, of which the evergreen bay

(Wharton 1978). The Pickney series is representative of the forest is considered to be climax (Monk 1968). The

soils found in seeps and stream margins supporting succession process requires a few hundred years without

evergreen bay forests. Soils of bayheads are less fertile than disturbance. In the more fertile shrub bog communities, fire

those of alluvial swamps with lower concentrations of appears to be a major influence in succession (Christensen

cations and a lower pH; however, they are more fertile than 1981). Kologiski (1977) used the term “fire disclimax” to

soils associated with cypress ponds (Monk 1966, 1968). describe the successional stage commonly known as pocosin

Fire Ecology

Frequent disturbance across the landscape often results in a

mosaic of vegetative cover types (Hamilton 1984). The

patchwork nature of evergreen bay forests is related to their

extreme susceptibility to fire, after which they may revert

back to any one of several freshwater, hydric vegetative

cover types depending on the intensity of the burn and

depth to the water table during and following the burn

(Monk 1968, Wells and Whitford 1976, Kologiski 1977,

Duever et al. 1982, Hamilton 1984, Bennett and Nelson

1991). Fire intensity determines the amount or depth of peat

burned away. Up to 6 feet (1.8 m) of peat were consumed

by a severe fire in the Okefenokee Swamp, removing the

base of support for the cypress (Taxodium) and tupelo

(Nyssa) trees present on the site and causing them to

collapse (Wharton 1978). Catastrophic fires also destroy

seed banks and kill root systems and stumps that might

survive less severe burns. Water-table depth during a fire

influences fire intensity and depth of the burn; after a fire,

water-table depth determines which of the available species

will be able to recolonize the site. With shallow burns, as

may occur when water tables are high, bay swamps may

revert to pine swamps; with deeper burns, they may revert

to cypress-gum ponds (Penfound 1952, Monk 1968). With a

devastating surface fire, bay swamps may be replaced by

Atlantic white-cedar [Chamaecyparis thyoides (L.) B.S.P.];

and with recurrent fire, the bay swamp, pond pine-slash

pine wetlands, and Atlantic white-cedar bogs may revert to

shrub bogs (Monk 1968). After a fire, pocosins may return

to a pre-fire pocosin condition or develop into an Atlantic

white-cedar bog, a sedge bog, an evergreen bay forest, or a

deciduous bay forest (Monk 1968, Wells and Whitford

1976, Kologiski 1977, Duever et al. 1982, Bennett and

Nelson 1991).

Most ecologists studying these systems agree that a

successional relationship exists between sedge bogs, shrub

bogs, pocosins, Atlantic white-cedar bogs, pine swamps,

cypress-gum ponds, and bay forests (Penfound 1952,

and also suggested that the evergreen bay forest would

eventually dominate.

On the other hand, Christensen et al. (1981) also noted that

in the absence of fire, many ombrotrophic shrub bogs show

little signs of succeeding to swamp forests and that some

shrub bogs have been relatively stable for several thousand

years. Otte (1981) proposed a succession sequence driven by

nutrient levels, with the bay forest as a seral stage and the

short pocosin as the equilibrium stage. Richardson and

Gibbons (1993) observed gradients in phosphorus (P)

availability and the nitrogen:phosphorus (N:P) ratio

associated with differences in cover type, i.e., short pocosin

versus bay forest. The nutrient-driven theory of succession is

also supported by pollen analysis. This form of succession

occurs in conjunction with paludification (Richardson and

Gibbons 1993).

Depth of peat or, more precisely, depth to the mineral soil

below the peat layer appears to be the major fertility factor

influencing succession and community types (Christensen et

al. 1988 as cited by Richardson and Gibbons 1993). Many

shrub bogs and shrub pocosins have a deeper layer of peat

than do bay forests and only a minor canopy component of

stunted tree species (Buell 1946, Bennett and Nelson 1991,

Richardson and Gibbons 1993). Fire reduces peat

accumulation and releases nutrients tied up in organic matter,

suggesting that fire and fertility are intimately related and

both may play a role in succession and stability.

Plant composition of these systems is also determined by

frequency of fire as well as fire intensity (Monk 1968,

Christensen 1981, Taggart 1981). Fire cycles of 50 to 150

years are required for the development of mature evergreen

bay forests (Wharton 1978). Buell (1946) and Monk (1966)

believed that the climax vegetation community of a Carolina

bay shrub bog was the broadleaf bay forest and also

considered this forest type successor to Atlantic white-cedar

stands and pine pocosins when fire was absent from the

ecosystem for long intervals. Buell (1946) went so far as to

suggest that the dominant climax tree species would be

swampbay (also known as redbay) [P. pubescens (borbonia)]
4

due to its extreme shade tolerance. In an 80-year-old, remain tied up in the slowly decomposing litter, especially on

declining Atlantic white-cedar stand in Brunswick County, inherently poor sites with deep peat accumulations

North Carolina, Buell and Cain (1943) noted that swampbay (Christensen 1981). However, Monk (1968) indicated that

was the most abundant tree species in the understory, with soil fertility was more important in controlling the direction

3,967 individuals per acre (98 individuals 100 m ). of succession than in limiting the advancement of -2

Sweetbay had 810 individuals per acre (20 individuals 100 succession. Many pocosin plants seem to require fire to

m ). No Atlantic white-cedar seedlings were found and 90 complete their life cycle, and the absence of fire may be -2

percent of all seedlings present were swampbay. Kologiski more of a disturbance than a very intense wildfire

(1977) also stated that the most common seedling in many (Christensen 1981, Christensen et al. 1981). Prescribed fire

of the evergreen bay forest stands of the Green Swamp in has not been an acceptable substitute for wildfire and does

North Carolina was swampbay. not provide conditions necessary for regeneration. Gresham

In addition to fire frequency and intensity, plant degree of soil disturbance, such as would occur from a very

composition is also influenced by site hydrology. Short intense wildfire, for successful seedling recruitment.

pocosins have been associated with high summer water

tables and anaerobic conditions throughout the year, In summary, plant composition in shrub bog/bay forest

whereas tall pocosins and bay swamps have a highly systems is determined by fire frequency and intensity,

seasonal water table (Bridgham and Richardson 1993). In climate, hydrology, and site fertility. Fire frequency and

areas with a defined moisture gradient, shrub bogs gradually intensity are influenced by climate and hydrology, and site

give way to swamp forests as moisture increases. The fertility is influenced by hydrology and fire frequency and

spatial progression is characterized by decreasing shrub intensity. Regenerative capacity, i.e., potential seed banks

diversity and increasing tree diversity, in association with and living rootstocks, is also determined in part by fire

decreasing peat depth and increasing nutrient availability intensity and frequency. The complex web of interactions

and productivity (Christensen et al. 1981). controlling succession within these depressional wetlands

Site hydrology, i.e., duration and depth of flooding, and types, one of which is the evergreen bay forest. Due to the

climatic factors, i.e., precipitation and lightning strikes, also long fire cycle required to achieve this cover type and the

influence fire frequency and intensity in shrub bog/bay longevity of the regenerative components of a bay forest, the

forest systems. Slightly elevated areas dry out more mere existence of an evergreen bay forest suggests it is

frequently, and periodic droughts increase the possibility of indeed both climax and “ancient” relative to surrounding

intense fires. However, bay swamps associated with seeps cover types occurring within depressional wetlands. 

and streamheads seldom dry out due to the constant seepage

of groundwater into the peat substratum, which is capable

of absorbing and retaining large quantities of water

(Wharton 1978).

Alteration of the water table by agricultural and silvicultural

drainage practices over the past years has increased the

frequency of dry periods and subsequently the possibility of

fires in the Coastal Plain. Such management practices may

have inadvertently interrupted the succession of shrub bogs

to bay forests and severely reduced in size or damaged

mature bay forests (Buell 1946, Monk 1966, Christensen

1981). However, a high frequency of fire in the Southeast

before 1800 has been documented by early explorers and

attributed to the activity of Native Americans (Christensen

1981). Even with the disturbance of the natural hydrology,

fires may be less frequent today than they were 200 years

ago.

Fire is necessary to the cycling of nutrients in the shrub

bog/bay forest system. Shrub bogs may stagnate if nutrients

and Lipscomb (1985) reported that Gordonia required a high

ensures myriad possible alternatives in vegetative cover

Life History and Community Associates

The floristic richness and species diversity of bay forests are

relatively low compared with other southeastern forest types

(Buell 1946, Monk 1968, Abrahamson et al. 1984). As stated

in the narrative description, bay forests are usually

dominated by the three bay species: loblolly-bay, sweetbay,

and redbay.

According to Silvics of North America, loblolly-bay is a

small-to-medium-sized tree or shrub (Gresham and

Lipscomb 1990). At 10 years of age, specimens averaged

21.3 feet (6.5 m) in height and 2.2 inches [5.6 centimeters

(cm)] in diameter at breast height (d.b.h.). Measurements of

older specimens were not reported, although individuals at

least 25 years old were noted. Elias (1980) reports the

species to be short-lived with a maximum height of 65.6 feet

(20 m) and diameter of 19.7 inches (50 cm). The National

Champion, located on the Ocala National Forest, has a
5

circumference of 13.4 feet (4.09 m) a diameter of 4.3 feet Bay forest communities usually have a dense understory.

(1.31 m), a height of 95.2 feet (29 m), and a crown spread Shrub, vine, and herbaceous species include the following:

of 52.5 feet (16 m). Loblolly-bay rarely occurs in pure fetter-bush (Leucothoe racemosa D. Don), tetter-bush 1

stands (Gresham and Lipscomb 1985). The species is [Lyonia lucida (Lam.) K. Kosh], swamp cyrilla (Cyrilla

considered shade tolerant and is a strong competitor, but it racemiflora L.), buckwheat-tree or titi [Cliftonia monophylla

is extremely sensitive to fire. Seedlings seem to require (Lam.) Britton ex Sarg.], maleberry [L. ligustrina (L.) DC],

relatively open conditions and exposed soil for sweet pepperbush (Clethra alnifolia L.), inkberry [Ilex

establishment. Few seedlings have been observed in the glabra (L.) Gray], gallberry (I. lucida), sweet gallberry [I.

field. Stump and root-collar sprouts appear to be the most coriacea (Pursh) Chapm.], American holly (I. opaca Ait.),

common form of regeneration for this species. dahoon holly (I. cassine L.), possumhaw ( I. decidua Walt),

Sweetbay is also listed as a slow-growing, small-to- virginica L. Virginian), greenbrier (Smilax spp.), zenobia

medium-sized tree (Priester 1990). It is considered a shrub [Zenobia pulverulenta (Bartr.)], leather leaf [Cassandra

in the northern reaches of its range (New Jersey), where it calyculata (L.) Moench], sheepkill (Kalmia augustifolia L.),

attains a height of 23.6 to 59.1 inches (60 to 150 cm). In the and cane [Arundinaria gigantea (Walt.) Chapm.] (Buell

southern portion of its range (Florida), it varies in height 1946, Porcher 1966, Monk 1968, Waggoner 1975,

from 49.2 to 98.4 feet (15 to 30 m) and in d.b.h. from 3.9 to Abrahamson et al. 1984). Cassandra calyculata is listed on

35.4 inches (10 to 90 cm). A record specimen measuring the rare/threatened/endangered plant list (Bennett and Nelson

50.4 inches (128 cm) d.b.h. and 91.9 feet (28 m) tall has 1991). Several ferns and mosses have also been listed in the

been recorded in Florida; however, the age of this literature as commonly occurring in bay forests. These

individual was not given. Individuals up to 70 years old include Osmunda cinnamomea, O. regalis, Woodwardia

were reported in the understory of a declining 80-year-old, virginica, W. areolata, and Sphagnum spp. (Porcher 1966,

Atlantic white-cedar stand in North Carolina (Buell and Kologiski 1977, Wharton 1978, Barry 1980). The

Cain 1943). Early growth of the sweetbays was slow, but herbaceous component is usually sparse (Nelson 1986) but

their growth rate increased as the growth rate of the cedars may include partridge berry (Mitchella repens L.) and wild

declined. Regeneration is best in natural openings or ginger (Hexastylis arifolia) (Barry 1980).

clearcuts, although seedlings are fairly tolerant of shade and

competing vegetation (Priester 1990). However, Buell and

Cain (1943) found no seedlings of sweetbay in the cedar

stand mentioned above. Like loblolly-bay, sweetbay also

produces stump sprouts. Sweetbay is considered resistant to

fire but will succumb after repeated burning.

Redbay is also listed as a tree or a shrub with size and

growth habit varying over its range. Heights up to 68.9 feet

(21 m) have been reported along with diameters of 35.8

inches (91 cm) (Brendemuehl 1990). Redbay occurring in

pocosins has been described as a shrub. Ages associated

with these dimensions were not reported. Redbay is tolerant

of shade but also grows well in the open. As previously

mentioned, redbay seedlings were abundant under a mature

Atlantic white-cedar canopy (Buell and Cain 1943).

However, reproduction may be erratic, and poor growth

forms often occur under overstory competition

(Brendemuehl 1990). Fire damage to redbay is severe and

may interfere with reproduction.

wax-myrtle (Myrica cerifera L.), Virginia willow (Itea

Age Structure

There is little information in the literature on age structure

for the dominant tree species in evergreen bay forests. They

are all described as moderately slow growing, and yet

specimens have achieved heights of 98.4 feet (30 m) and

diameters of 36.2 inches (92 cm). Loblolly-bay averaged 9.1

and 14.2 inches (23 and 36 cm) per year in height growth

and 0.2 inches (0.58 cm) per year in diameter growth for two

separate sites on the Coastal Plain of South Carolina

(Gresham and Lipscomb 1985). At these growth rates, it

would require about 100 years to achieve dimensions of 75.5

feet (23 m) tall and 22.8 inches (58 cm) d.b.h. One bay tree

located on the Hofmann Forest in North Carolina was

reportedly 85 years old. However, specimens 50 to 150 2

years old do not meet the popular concept of “old growth” or

“ancient forest.”

The absence of relatively “old” individuals of the dominant

tree species in a bay forest stand does not necessarily

 Personal communication. 1994. Laura Lowery, Ocala National Forest, 1

Lake George Ranger District, 17147 East Highway 40, Silver Springs, FL Personal communication. 1994. Richard Braham, Professor, North

34488-5849. Carolina State University, Raleigh, NC 27695.

2
6

indicate the natural longevity of those species but may sweetbay were the other major tree species in the

indicate frequent fires that prevent aboveground community.

components from reaching old age. However, stumps and

rootstocks partially protected from severe fire damage may In a study describing the influence of fire on a typical

be old. Both loblolly-bay and sweetbay commonly “blackgum bay” in the Okefenokee Swamp in Georgia, the

regenerate by means of stump and root-collar sprouts three bay species made up 24 percent and 54 percent of the

(Gresham and Lipscomb 1985). Wharton (1978) considered total number of tree stems counted along two 50-chain

the bay swamp one of Florida’s oldest and most stable transects (Cypert 1961) (table 1). Sweetbay was second only

environments because of the bay’s ability to stump sprout to blackgum in total number of stems for both transects.

following fire. Therefore, it may be appropriate to assign Basal areas for the three bay species combined were 28.5 and

old-growth status to those plant communities with 77.2 square feet per acre (6.54 and 17.7 m ha ), and total

individuals whose propagating parts are long-lived, whether basal area averaged 202.6 square feet per acre (46.47 m ha

) for the two transects. Basal area of sweetbay was second

standards. With temporally dynamic systems, such as the only to blackgum for both transects. Fire-induced mortality

bay forest/Atlantic white-cedar bog/evergreen shrub bog, it along the two transects averaged 5 and 50 percent for the bay

may be more important to recognize the longevity of the species. Fire damage in this section of the swamp was

nonequilibrium ecosystem rather than that of the current considered typical.

stand of individual aboveground stems.

Stand Structure

There are few quantitative data in the literature on stand

structure for evergreen bay forests of any age, much less

those considered mature. Gresham and Lipscomb (1985)

detailed 50 sites on the South Carolina Coastal Plain

supporting loblolly-bay (table 1). For their purposes, these

sites had only to include one loblolly-bay specimen larger

than 1.2 inches (3 cm) d.b.h. and, therefore, the sites studied

cannot all be considered bay forest stands. Redbay was also

a dominant tree species on these sites with sweetbay

occurring as well. The three other major tree species were

blackgum [Nyssa sylvatica var biflora (Walt.) Sarg.],

loblolly pine (Pinus taeda L.), and pond pine (P. serotina

Michx.), together with the two dominant bay species, they

comprised over 60 percent of the average site composition

and 84 percent of the basal area. The three bay species

alone averaged 299 stems per acre [740 stems per hectare

(ha )] (39 percent of the total) and a basal area of 30.7 -1

square feet per acre (7.05 m ha ) (28 percent of the total). 2 -1

Shrub densities averaged 18,728 stems per acre (46,278

stems ha ), with L. lucida and C. alnifolia comprising 73 -1

percent of the shrub composition.

Braham (see footnote 2) collected data in a bay forest at the

Horticulture Crops Research Station, Clinton, NC.

Loblolly-bay made up 58 percent of the total basal area and

had the largest number of stems per ha (table 1). Red maple

(Acer rubrum L.) was second with 16 percent of the total

basal area and 130 stems per acre (321 stems ha ). Swamp -1

tupelo, sweetgum (Liquidambar styraciflua L.), redbay, and

2 -1

2 -

the aboveground shoot is old by currently accepted 1

In three other areas of the swamp that were severely burned,

bay species made up 80 percent of 117 stems per acre (290

stems ha ), 71 percent of 21 stems per acre (52 stems ha ), -1 -1

and 8 percent of 203 stems per acre (501 stems ha ) before -1

the fire. All stems of the bay species were killed by the fire;

however, 17, 6, and 15 bay sprouts per acre (43, 15, and 37

bay sprouts ha ) were present several years after the fire. -1

Pre-fire basal areas for the bay species were as follows for

the three study areas: 80.7, 2.9, and 1.4 square feet per acre

(18.5, 0.67, and 0.32 m ha ), and for all tree species 2 -1

combined were 121.6, 11.8, and 95.1 square feet per acre

(27.9, 2.7, and 21.8 m ha ), respectively. These values 2 -1

represent a wide range of stand conditions on sites

supporting typical bay forest vegetation.

In a typical South Carolina pocosin, tree densities and basal

areas were lower than in other wetland forest types (Jones

1981) (table 1). Pond pine was most numerous, with

loblolly-bay second in number. However, pondcypress

[Taxodium distichum var. nutans (Ait.) Sweet] had greater

basal area than loblolly-bay. Redbay and sweetbay densities

combined had 10 stems per acre (25 stems ha ) with a -1

combined basal area of 0.4 square feet per acre (0.08 m ha 2 -

). Other tree and large shrub species on the site included 1

swamp tupelo, red maple, wax-myrtle, and dahoon holly.

Jones (1981) also provides some additional information on

diversity and community structure of six bay forest sites

located in South Carolina. These sites averaged 11 tree

species and 14 shrub species, a tree basal area of 145.2

square feet per acre (33.3 m ha ) and a shrub cover of 10.7 2 -1

inches per foot (88.9 cm m ). -1
7

Richardson and Gibbons (1993) summarized stand

characteristics of short pocosins, tall pocosins, and bay/gum

forests showing results similar to those reported above

(table 1). Only tall pocosins had tree-size (loblolly) bay

trees, but numbers and basal areas were low. Pond pine, red

maple, and Atlantic white-cedar were the only other tree

species present in the tall pocosin. The three bay species

made up
8

Table 1—Stand structure characteristics in old-growth evergreen bay forests and related seral communities

Bay forest

Gordonia sites Transect A Transect B SC pocosin Short pocosin Tall pocosin Bay/gum forest Hoffmann forest community a b b c d d d e e f

___________ ____________ ____________ ___________ ____________ ____________ ____________ _____________ _____________

Basal Basal Basal Basal Basal Basal Basal Basal Basal

Species area Density area Density area Density area Density area Density area Density area Density area Density area Density

m /ha stems/ha m /ha stems/ha m /ha stems/ha m /ha stems/ha m /ha stems/ha m /ha stems/ha m /ha stems/ha m /ha stems/ha m /ha stems/ha 2 2 2 2 2 2 2 2 2

Gordonia lasianthus 4.64 322 0.54 11 1.87 24 0.88 125 - - - - 0.04 13 .98 233 14.51 93 17.26 482

Persea borbonia 2.15 343 .11 4 3.57 42 .06 18 - - - - - - - - 4.74 308 - - - - 1.04 68

Magnolia virginiana .26 75 5.90 53 12.25 114 .02 7 - - - - - - - - .37 75 - - - - .28 99

Nyssa sylvatica 3.91 211 33.95 156 23.73 123 .42 77 - - - - - - - - 7.13 33 - - - - - - - -

N. biflora - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2.88 68

Pinus taeda 5.32 134 - - - - - - - - - - - - - - - - - - - - - - - - - - - - .28 6

P. serotina 4.93 134 - - - - - - - - 8.70 538 3.89 395 2.93 156 5.10 166 11.92 30 - - - -

P. elliotti - - - - - - - - .04 2 - - - - - - - - - - - - - - - - - - - - - - - -

Taxodium ascendens - - - - - - - - - - - - 1.34 103 - - - - - - - - - - - - - - - - - - - -

T. distichum - - - - 2.43 12 1.28 - - - - - - - - - - - - - - - - - - - - - - - - - -

Quercus nigra - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .29 31

Acer rubrum - - - - 1.60 53 1.69 23 .07 7 - - - - .04 13 15.07 133 - - - - 4.80 321

Chamaecyparis thyoides - - - - - - - - - - - - - - - - - - - - 2.08 75 - - - - - - - - - - - -

Liquidambar styraciflua .77 102 - - - - - - - - - - - - - - - - - - - - 18.88 175 - - - - .81 6

Ilex cassine - - - - 1.59 98 .24 6 .01 4 - - - - - - - - - - - - - - - - - - - -

I. opaca - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .59 86

Myrica cerifera .46 156 - - - - - - - - .04 11 - - - - - - - - - - - - - - - - - - - -

Symplocos tinctoria - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1.23 3

Miscellaneous 2.37 435 .21 7 1.95 74 - - - - - - - - - - - - .43 108 - - - - .40 216

Total 24.81 1912 46.33 394 46.62 408 11.54 890 3.89 395 5.09 257 52.7 1231 26.43 123 29.86 1386

 Gresham and Lipscomb 1985. a

 Cypert 1961. b

 Jones 1981. c

 Richardson and Gibbons 1993. d

 Personal communication. 1994. Richard Braham, Professor, North Carolina State University, Raleigh, NC 27695. e

 Located in Sampson County, North Carolina. f
9

49 percent of the stems per acre and 12 percent of the basal In North Carolina, Bridgham and Richardson (1993)

area in the bay/gum forest. Other dominant tree species in studied the soil chemistry along a hydrology gradient in a

that stand included red maple, sweetgum, blackgum, and freshwater peatland comprised of short pocosin, tall

pond pine. Sweetgum and red maple accounted for 36 pocosin, and gum swamp. Bay species were not listed as

percent and 27 percent of the basal area, respectively, and major vegetation components of these communities;

only 14 percent and 11 percent of the stems per acre.

Soils

Soils of bay forests are typically histosols, organic soils

whose fertility depends on the hydrologic conditions.

However, bay forest species can also be found on

spodosols, inceptisols, ultisols, and to a lesser degree

entisols and mollisols (Gresham and Lipscomb 1990).

Variations in size and growth habit reported for the

dominant tree species are probably related to differences in

soil-site characteristics of the different soil orders. Elevated

areas that depend on precipitation for nutrients and water

(ombrotrophic) have the poorest productivity (Bridgham

and Richardson 1993). However, poor sites may have

greater species diversity due to the inability of any one

species to dominate (Christensen 1981). Richardson and

Gibbons (1993) suggest that the ecosystem gradient from

short to tall pocosin to bay forest represents a natural

gradient of increasing P availability and decreasing N:P

ratio.

Accumulation of peat in the substrate is a common attribute

of bay forests. Buell (1946) described in detail the soil

profile in a typical Carolina bay—Jerome Bog in North

Carolina. This particular bay had a small bay forest stand

along its western edge. Peat accumulations ranged in depth

from 4 to 11 feet (1.2 to 3.4 m) and consisted of a surface

black peat and an underlying brown peat. In the deepest

section of the bay, an underlying clay lens was also present

over a sand layer. The surface of the bay was described as a

“continuous thick, coarse, tough mat of tree roots and the

roots and rhizomes of shrubs,” indicating a shallow,

surface-rooting habit in the peat substrate. The surface

black peat was described as fine, soft, and sticky when wet,

drying to a hard, brittle mass when dry, containing charred

plant fragments and fine charcoal throughout, with pollen in

the lower portion. The layer of black peat was thinnest

under the bay forest. The underlying brown peat contained

partially decomposed plant fragments, charcoal, numerous

logs, and an abundance of pollen. Both the logs and the

pollen were in a well-preserved state. The abundance of

charcoal in the peat substrate, particularly its presence in the

deepest sections of the underlying layer of brown peat,

confirms the historical importance of fire in the shrub

bog/bay forest ecosystem.

however, it is likely that soil chemistry is similar between

these communities and evergreen bay forest sites, given the

relationships between bay forests and pocosins. Both short

and tall pocosins were nutrient-deficient with low levels of

total and available P, N, and basic cations and a low pH.

They differed primarily in seasonal hydrology and peat

depth. Gum swamps had high levels of N and P but low

levels of exchangeable calcium (Ca) and magnesium (Mg)

and a low percent base saturation.

Richardson and Gibbons (1993) summarized Walbridge’s

(1986) soil chemistry work on pocosins and bay forests in

North Carolina and found results similar to those of

Bridgham and Richardson (1993) described above.

Although pH values were similar among the three site types

(3.7 to 3.9), exchangeable and total P as well as total N

levels were higher in the bay forest than in the short and tall

pocosins. Exchangeable P values ranged from 5.5 to 30.9

pounds per acre [6.2 to 34.6 kilograms (kg) ha ] and total P -1

values ranged from 17.5 to 105.3 pounds per acre (19.6 to

118 kg ha ) for short and tall pocosin and bay forests. Total -1

N values were 1,002.8, 847.6, and 1,993.2 pounds per acre

(1124, 950, and 2234 kg ha ) for short pocosin, tall -1

pocosin, and bay forests, respectively.

Christensen et al. (1988) also studied plant communities on

peat and hydric mineral soils in the Croatan National Forest

in North Carolina and found that pocosin soils had greater

peat depth, exchangeable Mg and potassium (K), and cation

exchange capacity and lower bulk density, extractable P,

Ca:Mg ratios, and pH than the other plant communities

studied.

Gresham and Lipscomb (1985) described soils associated

with loblolly-bay and redbay on the South Carolina Coastal

Plain. These included Leon sand, Lynn Haven fine sand,

Rutledge loamy sand, Pickney loamy fine sand, and Chipley

fine sand. The surface peat layer of these soils ranged from

1.2 to 5.6 inches (3 to 14 cm) thick. All soils were low in

pH, ranging from 3.2 to 4.8. Also in South Carolina, Jones

(1981 as cited by Sharitz and Gibbons 1982) described soils

supporting bay forest stands as having more than 15.8

inches (40 cm) of organic substrate, 54 percent organic

matter, 59 percent sand, 31 percent silt, and 10 percent clay.

In a typical Florida bayhead dominated by loblolly, sweet,

and redbay, Monk (1966, 1968) described soil as being
10

lower in Ca, Mg, K, Ca:Mg ratio, Ca:K ratio, natural preserves. Peat mining is another threat to pocosins

milliequivalents of cations, P, and pH compared with mixed and bay 

deciduous hardwood swamps found in Florida. These

edaphic features were strongly related to the dominant tree

species present in each of the swamp types studied. The

greater longevity of evergreen foliage and high nutrient-use

efficiency may give bay species an advantage over

deciduous species on infertile sites (Christensen et al.

1981).

Also in Florida, Abrahamson et al. (1984) listed the soil

series Sanibel and Pompano depressional, very poorly

drained and poorly drained, respectively, as common to

bayheads located on the Archbold Biological Station, a

3,904.2-acre (1580-ha) biological preserve located on the

Lake Wales Ridge in Highlands County. The three

bayheads found on the station occupied only 13.6 acres

(5.52 ha) or 0.35 percent of the total land area of the station.

Both soil types had a surface layer of muck; however, the

layer was thinner on the Pompano depressional soil series.

Nutrient analysis of the soil found it similar to other soil

series supporting bay forests. Major nutrients averaged 2.1,

51.2, 42.2, and 57.2 pounds per acre (2.3, 57.4, 47.3, and

64.1 kg ha ) of P, K, Ca, and Mg, respectively, and pH -1

averaged 4.7. Phosphorus and Ca values were lower than on

other sites on the station and K and Mg values were high to

intermediate compared to other forested sites.

Snags and Downed Woody Debris

No quantitative information was available in the literature

on numbers of snags per acre or the amount of downed

woody debris found in bay forest stands.

Threats to Existence

Many sites inhabited by bay species are so unproductive as

to have limited usefulness in silviculture or agriculture.

However, the use of phosphorus fertilization and bedding

with minor drainage by timber companies has resulted in the

establishment of pine plantations on many acres of

pocosins. For example, in the 17-year period after 1962,

pocosin acreage in North Carolina was decreased by 69

percent (Ash et al. 1983). Nevertheless, some timber

companies are beginning to recognize the value of the rare

bay forest type and are designating these small patches as

3

 Personal communication. 1994. Mac Baughman, Westvaco Corporation, 3

P.O. Box 1950, Summerville, SC 29484.
11

forests. Interest in bioenergy fuels resulted in an increase in

the number of permits to mine peat from North Carolina

pocosins during the early 1980’s (Ash et al. 1983).

Carolina bays are also subject to disturbance; half of all

bays in South Carolina identified by Bennett and Nelson

(1991) had one-fifth or more of their ellipse disturbed.

Types of disturbance included ditches, row cropping, pine

plantations, logging, development, roads, rights-of-way, and

farm ponds. Eighty percent of all disturbed bays had

multiple disturbances. However, as with some of the

pocosins, State heritage trust programs are attempting to

identify and protect as many relatively undisturbed Carolina

bays as possible.

Aside from conversion, the greatest threat to “old-growth”

bay forests is wildfire. Silvicultural practices, such as minor

drainage, and agricultural use of adjacent upland areas

could indirectly influence both the frequency and intensity

of wildfire in shrub bogs and mature bay forests. A

lowering of the water table could result in more frequent

and deeper burns. On the other hand, prescribed fire and

fire suppression, as practiced in forest management, could

decrease the occurrence of wildfire, thus allowing the

succession of shrub bogs to mature bay forests. For that

reason, current forest management practices may promote

the development of mature bay forests. At the same time,

intense wildfires may be required for seedling recruitment,

and lack thereof may prevent regeneration of many bay

forest species. Drainage of these systems is also a form of

disturbance, stimulating productivity and reducing species

diversity (Christensen 1981).

The very existence of mature bay forests today is the result

of a series of stochastic events that provided an exposed

mineral-soil seedbed (probably the result of catastrophic

wildfire) and yet an extended period free from wildfire.

This had the combined effect of seedling establishment and

uninterrupted succession to the climax condition—mature,

evergreen bay forest. Management that will produce such a

fortuitous chain of events might be difficult, if not

impossible, in light of unpredictable weather patterns, landuse planning for adjacent areas, and public health concerns.

It is probably more feasible to maintain current sites with

adequate fire suppression and conservation easements than

to attempt to create new mature bay forests. Fire

suppression during the seral stages of bay ecosystem

succession may lead to the eventual development of a

mature bay forest, but may not be economically feasible or

desirable in some circumstances. 

Representative Stands

Several representative stands of evergreen bay forests still

exist throughout the Southeastern United States and can be

found associated with each of the physiographic features

described above. However, because little information is

available on the ages of these stands, it is inappropriate to

assume that they are “old-growth” bay forests. The

individuals suggesting their inclusion in this list believed

that these stands came closest to what might be considered

“old growth” for this forest type. Further research in these

areas would provide additional information regarding (1)

age distributions of perennating parts, as well as

aboveground stems; (2) successional relationships between

pocosins, bay forests, and Atlantic white-cedar bogs; and

(3) the influence of hydrology on peat accumulation, fire

frequency and intensity, and nutrient cycling in these

dynamic, interrelated systems.

North Carolina

The Hofmann Forest owned by the North Carolina Forestry

Foundation has approximately 622.7 acres (252 ha) of bay

forest in two forest-management units (FMU 218 and 404).

These areas have reportedly not burned for over 40 years. In

1992, the average age of the stands was 56 years with one

loblolly-bay 85 years old. Loblolly-bay was the dominant

species followed by pond pine (table 1). This area is slowly

succeeding from a pond pine stand to a bay forest in the

absence of fire, and stands dominated by both species are

interspersed in a patchwork mosaic (see footnote 2).

Dr. Braham (see footnote 2) also described a bay

community in Sampson County, North Carolina, that he

visited in 1988 (table 1). The stand contained some large

specimens of loblolly-bay, one of which until recently had

been on record as the North Carolina State Champion.

Several trees in the stand exceeded 20.9-inches (53-cm)

d.b.h.

Several other areas in North Carolina, classified as

pocosins, are reported to have some bay forest intact. These

include Angola Bay, Holly Shelter, and Green Swamp, all

located in the southeastern corner of North Carolina.

Angola Bay and Holly Shelter were classified by Wells

(1946) as estuary bays, the elevated flat bottoms of ancient

estuaries when sea levels were higher than those at present.

Angola Bay has about 20,015.1 acres (8100 ha) of pocosin,

Holly Shelter about 29,899.1 acres (12,100 ha), and Green

Swamp about 13,837.6 acres (5600 ha) (Taggart 1981). The

acreage of mature bay forest is unknown and is intermixed

with more typical pocosin vegetation. Angola Bay and
12

Holly Shelter are owned by the State of North Carolina and Green Swamp is owned by The Nature Conservancy.

a portion of Kologiski (1977) described community structure in the

Green Swamp and noted that in 1977, bay forest existed in

areas that did not burn in 1955 and 1969, years of large fires

in the swamp. The most recent fire previous to those fires

was in 1932, suggesting that the bay forest areas were at

least 45 years old in 1977. Little recent information was

available for these sites.

South Carolina

River’s Bridge State Park, located off Highway 641 in

Bamberg County, has been reported to have a stand of old

evergreen bay forest. It fits the description of bay forests 4

associated with stream margins. 

Pigeon Pond (also known as Pigeon Bay) has also been

reported to have a stand of loblolly-bay trees. Pigeon Pond, 5

a 808-acre (327-ha) Carolina bay located off State Road

135 between Highways 311 and 176 in Berkeley County, is

owned by the Westvaco Corporation. It has been placed in

the company’s “unique stand category” and current plans

are to preserve the bay as a natural area (see footnote 3).

Bay trees in this Carolina bay are reported to be 11.9 to 14.2

inches (30 to 36 cm) in diameter.

Snuggedy Swamp, accessible only by boat, has also been

reported to have an old-growth evergreen bay forest.

Snuggedy Swamp is located on the Ashepoo River of the

ACE Basin in Colleton County. Additional information

concerning Snuggedy Swamp may be obtained from Mike

Prevost with The Nature Conservancy or Dr. Bert Pittman

of the South Carolina Heritage Trust Program.

Barry (1980) also mentions the existence of “a welldeveloped bay forest” as well as an Atlantic white-cedar

bog in Lexington County, South Carolina. Attempts to

verify their continued existence and to gain additional

information as to their locations were not successful.

Georgia

Seventeen Mile Creek in Coffee County has an excellent

example of a mature bay swamp, according to Wharton

(1978). There are about 98.8 acres (40 ha) of bay swamp

located along a 1.5-mile [2.4-kilometer (km)] stretch on the

 Personal communication. 1994. Richard Porcher, Professor, The Citadel, 4

171 Moultrie Street, Charleston, SC 29409.

 Personal communication. 1994. Steve Bennet, The South Carolina 5

Heritage Trust Program, Columbia, SC 29631.
13

eastern side of the stream. This bay swamp occurs at the The National Champion Loblolly-Bay tree is also located in

base of sandhills that are present only on the eastern side of Florida on the Ocala National Forest; however, it does not

the stream. Other cover types (according to Wharton 1978) occur in a typical bay forest. According to Laura Lowery

associated with the bay swamp include evergreen shrub with the USDA Forest Service (see footnote 1), it is located

bog, creek swamp, and upland, broadleaf, evergreen forest. in a rather unusual topographic setting—a 56.8-acre (23-ha)

Wharton states there is little evidence to suggest that the limestone sink with an underlying clay pan that occurs in a

mature evergreen shrub bog is in succession toward bay 882.2-acre (357-ha) longleaf pine “island” surrounded by

forest; the shrub bog appears to be a stable community. sand pine scrub.

Together, these plant communities occupy 200.2 acres (81

ha) of lowland along this creek bottom. The bay swamp is The Ocala National Forest does, however, have a

made up of mature loblolly-bay with lesser amounts of representative bay swamp in the area known as Rocky

sweetbay and redbay. Dominant trees were up to 15 inches Point. This site has been described as being an extensive,

(38 cm) in d.b.h. In a personal communication during the dry, pineland grading into a floodplain forest toward Lake

summer of 1994, Wharton indicated that most of the stand George and possesses many of the species considered

was still intact, to the best of his knowledge. typical of the evergreen bay forest type. The age of this

Wharton also recommends two other locations in Georgia

as examples of bay swamps—Ohoopee Sandhills in

Emanuel County and Whitewater Creek, where it crosses

Highway 137 in Taylor County. The Whitewater Creek Patches of bay forest are reported in the Conecuh National

community also contains Atlantic white-cedar in addition to Forest, located in southern Alabama on the Florida border

the typical bay species and shrubs. in Escambia and Covington Counties. These areas extend

The Okefenokee Swamp ecosystem also has areas mapped patches of bay forest occur as inclusions in other cover

as bay forests by McCaffrey and Hamilton (1984) with 80 types. These areas include (1) Bear Bay, located in

percent of the canopy cover made up of “broad-leaved Covington County in Bradley Quad T2NR24W Sector 27,

evergreen trees of medium height." Wharton (1978) 26, 34; (2) Wolf Thicket Bay, also located in Covington

classified the Okefenokee as a bog swamp but County in Wing Quad T1NR14E Sector 11, 12, 1; and (3)

acknowledged the presence of many related communities Blackwater Bay and Falco Bay located in Wing Quad

made up of bay species along with others typical of bay T1NR15E Sector 6, 5, 7, 8 and T1NR14E Sector 13, 18,

swamps, e.g., cypress, blackgum, and red maple. Crew respectively. Loblolly-bay has been found in only two

members of the USDA Forest Service, Forest Inventory and locations, although redbay and sweetbay are present

Analysis unit, reported pure stands of sweetbay in bays of throughout. (This information was obtained through Jarel

the Okefenokee with an average d.b.h. of 16.1 inches (41 Hilton and Chris Oberholster of the Alabama Natural

cm) and some individuals as large as 24 inches (61 cm) Heritage Program and through Suzanne Oberholster of the

d.b.h. in 1980 to 1981. The largest individuals appeared to USDA Forest Service.) 6

be in decline and may have been representative of “oldgrowth” at that time. Grand Bay Savannah Bioreserve is located on the border

Florida

The Bradwell Bay Wilderness Area, located in the Wakulla

Ranger District of the Apalachicola National Forest, has

been reported to have a stand typical of the bay forest type.7

8

stand was not given.

Alabama

across the border into the northern Florida panhandle. The

between Alabama and Mississippi on the coast below

Interstate 10 in Mobile and Jackson Counties. This natural

preserve has been reported to have patches of evergreen bay

 Personal communication. 1994. Mike Lick, USDA Forest Service, De 6

Soto National Forest, Black Creek Ranger District, Wiggins, MS 39577.

 Personal communication. 1994. Donna Streng, Tall Timbers Research Personal communication. 1994. Gerald Guala II, Florida Museum of 7

Station, Route 1, Box 678, Tallahassee, FL 32312. Natural History, University of Florida, Gainesville, FL 32611.

8
14

forest in a mosaic with other wetland cover types, such as been located in the State of Louisiana. The Kisatchie

titi-dominated shrub bogs and pond cypress strands. National Forest is the site of many such baygalls, 9 10 11

Mississippi

Grand Bay Savannah Bioreserve (described above for Louisiana in St. Tammany Parish and owned by The Nature

Alabama) also extends into Mississippi and may have Conservancy, is one of the best representatives of the bay

scattered patches of evergreen shrub bog and bay forest. forest type in this State. Overstory dominants include

Loblolly-bay is considered rare in Mississippi and bay in the shrub understory along with Cyrilla and Cliftonia,

forests in this State are composed primarily of the bay which is rare for Louisiana. Swamp blackgum individuals

species sweetbay with some redbay. However, five or six as large as 35.4-inches (90-cm) d.b.h. and sweetbay

sites have been reported to contain loblolly-bay, one of individuals 29.9- to 35.4-inches (76- to 90-cm) d.b.h. have

which is located on the DeSoto National Forest. This area is been reported.

located on the Black Creek Ranger District in Compartment

47 along Turkey Branch. The 148.3-acre (60-ha) site

includes a loblolly-bay forest and associated uplands and

has been nominated as a Research Natural Area. The

classification of this area as such should assure its

preservation for future study.12

Most of the other drainheads supporting bay forests are

mainly made up of sweetbay and were cutover in the 1930’s

and 1940’s. These areas, which support almost pure stands

of sweetbay, are small, some being only 5 to 7.4 acres (2 to

3 ha). The existence of mature bay trees on these sites is

questionable (see also footnote 6). In the future, some of 13

these areas will be managed by the national forest as “lands

unsuitable for timber” and may develop into mature bay

forests.

Louisiana

Baygalls with sweetbay and redbay exist in the form of

stream heads and drains, but currently loblolly-bay has not

14

supporting stands of large sweetbay; however, these stands

may not be very old nor do they contain some of the largest

sweetbay trees. Charter Oak Baygall, located in southeast

swamp blackgum, sweetbay, and red maple. Redbay exists

15

Summary

The evergreen bay forest cover type can occur on a variety

of habitat types (abiotic features of the landscape based on

land form and soil type) throughout the Atlantic and Gulf

Coastal Plains. A common characteristic among the diverse

landforms is the development of histic soils. Although

duration, frequency, and seasonality vary, periods of soil

saturation or soil inundation are common to sites supporting

bay forests. Hydrologic and nutrient input for such sites can

range from ombrotrophic to spring-fed, depending on the

local topography and hydrology. These differences in

hydrology, along with differences in soil type, lead to

differences in fertility. The depth of the peat or histic

horizon and the presence or absence of underlying mineral

soil also influence site fertility, and these taken together

strongly influence the successional relationships among

sedge bogs, shrub bogs, and bay forests. Fire also plays a

major role in the development of these systems, but its

importance depends on the local topography and hydrology.

All these site characteristics can vary significantly among

pocosins, Carolina bays, and intermittent drainage heads.

Although each of these landforms may support bay forest

plant communities, the direction of succession and the

position of each community type along the successional sere

may vary from location to location. Hence, a single

description of features indicative of old growth in these bay

forest systems is not necessarily appropriate nor

 Personal communication. 1994. Jarel Hilton, Alabama Natural Heritage 9

Program, Department of Conservation and Natural Resources, Division of

Lands, Folsom Administrative Building, 64 N. Union Street, Room 752,

Montgomery, AL 36130.

 Personal communication. 1994. Ron Wieland, Mississippi Natural 10

Heritage Program, Museum of Natural Science, 111 N. Jefferson Street,

Jackson, MS 39201-2897.

 Personal communication. 1994. Will McDearman, Department of Fish 11

and Wildlife, 6578 Dogwood View Parkway, Suite. A, Jackson, MS

39213.

 Personal communication. 1994. Steve Lee, USDA Forest Service, LA 70898-9000. 12

DeSoto National Forest, Black Creek Ranger District, Wiggins, MS 39577.

 Personal communication. 1994. Tom Cruise, USDA Forest Service, Heritage Program, Department of Wildlife and Fish, P.O. Box 98000, 13

DeSoto National Forest, Black Creek Ranger District, Wiggins, MS 39577. Baton Rouge, LA 70898-9000.

 Personal communication. 1994. Julia Larke, Louisiana State Heritage 14

Program, Department of Wildlife and Fish, P.O. Box 98000, Baton Rouge,

 Personal communication. 1994. Latimore Smith, Louisiana State 15
15

ecologically sound. Until these successional relationships

are better understood, it may be more appropriate to

consider preservation of representative systems with

examples of the full mosaic of the successional sere on a

variety of landforms.

The evergreen bay forest community is a rare and unique

system regardless of the age of individuals. As previously

discussed, the bay forest system as a whole, made up of the

various successional stages associated with this cover type,

is considered to be stable. Due to the susceptibility of some

of these systems to fire, aboveground components may not

be particularly old. However, belowground components,

including root stocks and seed banks involved in

regeneration, may be very old. Hence, old growth should be

evaluated in terms of both aboveground and belowground

components and community stability over time within the

natural cycles of disturbance. Obviously, more information

than is currently available in the literature is necessary to

make ecologically sound descriptions of these systems.

Recognizing that they are indeed rare, State and Federal

agencies, along with conservation groups, are making an

effort to set aside these bay forest systems. With further

study, more ecologically appropriate descriptions will be

possible.

Literature Cited

Abrahamson, W.G., A.F. Johnson, J.N. Layne, and P.A. Peroni. 1984.

Vegetation of the Archbold Biological Station, Florida: An example of

the southern Lake Wales Ridge. Fla. Sci. 47:209-250.

Ash, A.N., C.B. McDonald, E.S. Kane, and C. A. Pories. 1983. Natural

and modified pocosins: Literature synthesis and management options.

FWS/OBS-83/04. Rep. prep. for Div. of Biol. Serv., Fish and Wildl.

Serv., U.S. Dep.,Inter. Washington, DC.

Barry, J.M. 1980. Natural vegetation of South Carolina. Univ. of South

Carolina Press, Columbia. 214 p.

Bennett, S.H., and J.B. Nelson. 1991. Distribution and status of Carolina

Bays in South Carolina. S.C. Wildl. and Mar. Resour. Dep., Nongame

and Heritage Trust Sect. 88 p.

Brendemuehl, R.H. 1990. Persea borbonia (L.) Spreng. Red bay. 

P. 503-506 in Silvics of North America: Vol. 2, Hardwoods, Burns,

R.M., and B.H. Honkala (tech. coords.). U.S. Dep. Agric. Handb. 654.

877 p.

Bridgham, S.D., and C.J. Richardson. 1993. Hydrology and nutrient

gradients in North Carolina peatlands. Wetlands 13(3):207-218.

Brubaker, L.B. 1988. Vegetation history and anticipating future vegetation

change. P. 41-61 in Ecosystem management for Parks and Wilderness,

Agee, J.K., and D.R. Johnson (eds.). Univ. of Washington Press, Seattle.

Buell, M.F. 1946. Jerome Bog, a peat-filled “Carolina Bay.” Bul. Torrey

Bot. Club. 73:24-33.

Buell, M.F., and R.L. Cain. 1943. The successional role of southern white

cedar, Chamaecyparis thyoides, in southeastern North Carolina.

Ecology 24:85-93.

Christensen, N.L. 1981. Fire regimes in southeastern ecosystems. 

P. 112-136 in Fire regimes and ecosystem properties. U.S. Dep. Agric.

For. Serv. Gen. Tech. Rep. WO-26.

Christensen, N.L., R.B. Burchell, A. Liggett, and E.L Simms. 1981. The

structure and development of pocosin vegetation. P. 43-61 in Pocosin

wetlands: An integrated analysis of coastal plain freshwater bogs in

North Carolina, Richardson, C.J. (ed.). Hutchinson Ross Publ. Co.,

Stroudsburg, PA.

Christensen, N.L., R.B. Wilbur, and J.S. McLean. 1988. Soil-vegetation

correlations in the pocosins of the Croatan National Forest, North

Carolina. Biol. Rep. 88, U.S. Fish and Wildl. Serv., Washington, DC.

Cypert, E. 1961. The effects of fires in the Okefenokee Swamp in 1954

and 1955. Am. Midl. Nat. 66:485-503.

Davis, M.B. 1984. Climatic instability, time lags, and community

disequilibrium. P. 269-284 in Community ecology, Diamond, J., and

T.J. Case (eds.). Harper and Rowe, New York.

Duever, L.C., J.F. Meeder, and M.J. Duever. 1982. Ecological portion

Florida peninsula natural region theme study. Nat. Audubon Soc.

Ecosystem Res. Unit, Naples, FL. 398 p.

Elias, T.S. 1980. The complete trees of North America: Field guide and

natural history. Outdoor Life/Nature Books, Van Nostrand Reinhold

Co., New York. 948 p.

Gresham, C.A., and D.J. Lipscomb. 1985. Selected ecological

characteristics of Gordonia lasianthus in coastal South Carolina. Bul.

Torrey Bot. Club. 112(1):53-58.

Gresham, C.A., and D.J. Lipscomb. 1990. Gordonia lasianthus (L.) Ellis

Loblolly-Bay. P. 365-369 in Silvics of North America: Vol. 2,

Hardwoods, Burns, R.M., and B.H. Honkala (tech. coords.). U.S. Dep.

Agric. Handb. 654. 877 p.

Hamilton, D.B. 1984. Plant succession and the influence of disturbance in

the Okefenokee Swamp. P. 86-111 in The Okefenokee Swamp, Cohen,

A.D., D.J. Casagrande, M.J. Andrejko, and G.R. Best (eds.). Wetland

Surveys, Los Alamos, NM.

Jones, R.H. 1981. A classification of lowland forests in the northern

coastal plain of South Carolina. M.S. Thesis, Clemson Univ., Clemson,

SC. 177 p.

Kologiski, R.L. 1977. The phytosociology of the Green Swamp, North

Carolina. Tech. Bul. No. 250. N.C. Agric. Exp. Stn., Raleigh. 101 p.

McCaffrey, C.A., and D.B. Hamilton. 1984. Vegetation mapping of the

Okefenokee ecosystem. P. 201-211 in The Okefenokee Swamp, Cohen,

A.D., D.J. Casagrande, M.J. Andrejko, and G.R. Best (eds.). Wetland

Surveys, Los Alamos, NM.

Monk, C.D. 1966. An ecological study of hardwood swamps in northcentral Florida. Ecology 47:649-654.

Monk, C.D. 1968. Successional and environmental relationships of the

forest vegetation of north central Florida. Am. Midl. Nat. 79:441-457.

Nelson, J.B. 1986. The natural communities of South Carolina: Initial

classification and description. S.C. Wildl. and Mar. Resour. Dep., Div.

of Wildl. and Freshwater Fish. Columbia. 55 p.

Otte, L.J. 1981. Origin, development, and maintenance of pocosin

wetlands of North Carolina. Unpubl. rep. to the N.C. Nat. Heritage

Program, N.C. Dep. of Nat. Resour. and Com. Dev., Raleigh.

Penfound, W.T. 1952. Southern swamps and marshes. Bot. Rev. 

18:413-446.

Porcher, R.D., Jr. 1966. A florisitic study of the vascular plants in nine

selected Carolina bays in Berkley County, South Carolina. M.S. Thesis,

Univ. of South Carolina, Columbia. 123 p.
16

Priester, D.S. 1990. Magnolia virginiana L. Sweet Bay. P. 449-454 in Taggart, J.B. 1981. Pocosin natural areas in North Carolina. P. 171-182 in

Silvics of North America: Vol. 2, Hardwoods, Burns, R.M., and B.H. Pocosin wetlands: An integrated analysis of coastal plain freshwater

Honkala (tech. coords.). U.S. Dep. Agric. Handb. 654. 877 p. bogs in North Carolina, Richardson, C.J. (ed.). Hutchinson Ross Publ.

Richardson, C.J., and J.W. Gibbons. 1993. Pocosins, Carolina bays, and

mountain bogs. P. 257-310 in Biodiversity of the southeastern United Waggoner, G.S. 1975. Eastern deciduous forest. Vol. 1. Southeastern

States: Lowland terrestrial communities, Martin, W.H., S.G. Boyce, and evergreen and oak-pine region. Inventory of natural areas and sites

A.C. Echternacht (eds.). Wiley, New York. recommended as potential natural landmarks. Nat. Park Serv., Natural

Schafale, M.P., and P.A. Harcombe. 1983. Presettlement vegetation of

Hardin County, Texas. Am. Midl. Nat. 109:355-366. Walbridge, M.R. 1986. Phosphorus availability in acid organic coastal

Schalles, J.F. 1979. Comparative limnology and ecosystem analysis of

Carolina bay ponds on the upper coastal plain of South Carolina. Ph.D. Wells, B.W. 1928. Plant communities for the coastal plain of North

Diss., Emory Univ., Atlanta. 268 p. Carolina and their successional relations. Ecology 9:230-242.

Schalles, J.F., R.R. Sharitz, J.W. Gibbons, G.J. Leversee, and J.N. Knox. Wells, B.W. 1946. Vegetation of Holly Shelter Wildlife Management Area.

1989. Carolina Bays of the Savannah River Plant. SRO-NERP-18. 70 p. N.C. Dep. of Conserv., State Bul. 2.

Sharitz, R.R., and J.W. Gibbons. 1982. The ecology of southeastern shrub Wells, B.W., and L.A. Whitford. 1976. History of stream-head forests,

bogs (pocosins) and Carolina bays: A community profile. FWS/OBS- pocosins, and savannahs in the Southeast. J. Elisha Mitchell Sci. Soc.

82/04. U.S. Dep. Inter., Fish and Wildl. Serv., Div. Biol. Serv., 92:148-150.

Washington, DC. 93 p.

Sprugel, D.G. 1991. Disturbance, equilibrium, and environmental Nat. Resour., Atlanta. 287 p.

variability: what is “natural” vegetation in a changing environment?

Biol. Conserv. 58:1-18.

Co., Stroudsburg, PA.

History Theme Study NF 135. 206 p.

plain soils. Ph. D. Diss., Univ. of North Carolina, Chapel Hill.

Wharton, C.H. 1978. The natural environments of Georgia. Georgia Dep.
McKevlin, Martha R. 1996. An old-growth definition for evergreen bay forests and related seral

communities. Gen. Tech. Rep. SRS-3. Asheville, NC: U.S. Department of Agriculture, Forest

Service, Southern Research Station. 14 p.

This document describes old-growth conditions in an evergreen bay forest stand. Bay forests occur

throughout the Atlantic and Gulf Coastal Plains. However, they are considered rare and are present

across the landscape in a patchwork mosaic with other forest types in various stages of succession.

Bay forests can be found associated with pocosins, Carolina bays and sandhill seeps, stream heads,

and stream margins. The dominant species include loblolly-bay, sweetbay, and redbay, hence the

name evergreen bay forest. However, several other swamp species associates are common, as well

as many highly flammable shrub species. This forest type is subject to infrequent, high intensity,

widespread disturbances such as fire. Fire is necessary to the nutrient cycling of this forest type and

in conjunction with hydrology, controls succession. These stands are frequently inundated by

surface water, resulting in the development of histic soils low in fertility. Alteration of the

hydrology by man and catastrophic wildfire are considered to be the greatest threats to the existence

of bay forests.

Keywords: Carolina bay, disturbance, fire, hydric, loblolly-bay, peat, pocosin, redbay, shrub bog,
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