____________

The Authors:

____________

James S. Meadows, Research Forester, Southern Research Station, 

U.S. Department of Agriculture, Forest Service, Stoneville, MS 38776;

and Gregory J. Nowacki, Forest Ecologist, Region 10, U.S.

Department of Agriculture, Forest Service, Juneau, AK 99802.

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 USDA 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

Eastern Riverfront Forests

James S. Meadows and Gregory J. Nowacki

Introduction

Eastern riverfront forests fall into one of three types: (1)

nearly pure eastern cottonwood (Populus deltoides Bartr. ex

Marsh.) stands, (2) nearly pure black willow (Salix nigra

Marsh.) stands, and (3) typical riverfront hardwood stands

containing many species, but generally dominated by

sycamore (Platanus occidentalis L.), pecan [Carya

illinoensis (Wangenh.) K. Koch], green ash (Fraxinus

pennsylvanica Marsh.), sugarberry (Celtis laevigata Willd.),

and American elm (Ulmus americana L.). Both eastern

cottonwood and black willow are temporary, pioneer forest

types that become established on newly exposed river

margins. Both species are short-lived and individuals rarely

exceed 85 to 120 years of age. The eastern riverfront forest

generally succeeds both eastern cottonwood and black

willow forests, and represents an intermediate successional

stage between these pioneer types and the sweetgum

(Liquidambar styraciflua L.)-water oaks (Quercus nigra L.,

Q. phellos L., and Q. nuttallii Palmer) type on drier sites

and the overcup oak (Q. lyrata Walt.)-water hickory [Carya

aquatica (Michx. f.) Nutt.] type on wetter sites. Some

evidence indicates that cottonwood/willow forests begin to

break up at about 35 years of age and are replaced by

eastern riverfront forests by 85 years of age. The eastern

riverfront type lives for about 80 years before being

gradually invaded by sweetgum and water oaks. However,

repeated disturbances may allow eastern riverfront forests to

persist on a site for several generations.

Description of Eastern Riverfront Forests

Description

Eastern riverfront forests occur over a large portion of the

Eastern United States, essentially from the forest-prairie

margin eastward to the Atlantic coastline and from

Massachusetts to northeast Florida. These forests are most

abundant within the Mississippi River watershed and along

the East Coast, and are least common in the Appalachians.

As the name implies, the forest type is predominant on sites

immediately adjacent to large rivers and streams (i.e., river

banks and first bottoms, natural levees, sandbars, and

islands). Soils are alluvial and range widely in texture from

sand to clay. Soils are generally moist year-round due to

their topographic position and proximity to open water.

Flooding occurs seasonally on most sites and often damages

the vegetation. Because of flooding and rapid

decomposition rates, litter accumulation on the forest floor

is negligible except in depressions.

The principal species in eastern riverfront forests include

river birch (Betula nigra L.), sycamore, silver maple (Acer

saccharinum L.), American elm, eastern cottonwood,

swamp cottonwood (P. heterophylla L.), sweetgum, and

black willow. Live oak (Quercus virginiana Mill.) is an

important component in southern forests. Common

associates are red maple (A. rubrum L.), boxelder (A.

negundo L.), hackberry (Celtis occidentalis L.), slippery

elm (U. rubra Muhl.), black walnut (Juglans nigra L.), pin

oak (Q. palustris Muenchh.), swamp white oak (Q. bicolor

Willd.), green ash, sugarberry, water oak, and pecan. These

pioneer forests are restricted to riparian zones where intense

flooding, accompanied by ice and water scouring, routinely

occur. These naturally occurring perturbations expose

mineral soil, reduce competing undergrowth, and increase

surface light—conditions required by the shade-intolerant

species of this type. In this sense, flooding is considered a

rejuvenating force. Within a dynamic river system, the

location of these forests will shift as the river course

changes, remaining adjacent to the active channel. In the

absence of major flooding, these forests are susceptible to

encroachments by shade-tolerant species. Indeed, many

present-day stands are in jeopardy of successional change

because hydrologic alterations by humans (e.g., dam and

dike construction) have largely controlled this force in many

locations.

Associated Society of American Foresters Forest Cover

Types

One or more principal species in eastern riverfront forests is

an associate species in the following Society of American

Foresters forest cover types:

61—river birch-sycamore

62—silver maple-American elm

63—cottonwood

89—live oak

94—sycamore-sweetgum-American elm

95—black willow.
2

Physiographic Provinces (after Fenneman 1938)

Eastern riverfront forests are found in all physiographic contain many species but are usually dominated by

provinces except for New England (White Mountain, Green sycamore, pecan, green ash, American elm, and sugarberry

Mountain, and Taconic sections), Adirondack Mountains, and may also contain silver maple, river birch, boxelder, red

and Superior Upland. maple, and baldcypress (Putnam 1951, Putnam and others

Old-Growth Conditions

Living Tree Component

Eastern riverfront forests generally fall into one of three

types: (1) nearly pure eastern cottonwood stands; (2) nearly

pure black willow stands; and (3) typical riverfront

hardwood stands containing many species but generally

dominated by sycamore, pecan, green ash, sugarberry, and

American elm.

Eastern cottonwood establishes itself on newly formed

sandbars or newly exposed river margins. It forms nearly

pure stands and is regarded as a temporary, pioneer forest

type. Old-growth stands contain many large eastern

cottonwood trees up to 72 inches [183 centimeters (cm)] in

diameter at breast height (d.b.h.) and up to 175 feet [53

meters (m)] in height (Williamson 1913, Putnam and Bull

1932). Tree age at maturity ranges from 60 to 125 years;

most stands begin to break up at around 85 years of age as

significant mortality occurs (Williamson 1913, Putnam and

Bull 1932 ). Openings created by dead trees or windthrow

in old-growth eastern cottonwood stands are generally

occupied by sycamore, American elm, sugarberry, pecan,

and green ash (Putnam and others 1960). Because eastern

cottonwood is intolerant of shade, stand density is generally

low and may not exceed 32 trees per acre [79 trees per

hectare (ha)] at stand maturity (Williamson 1913).

Black willow becomes established on newly exposed mud

flats along rivers. It forms nearly pure stands and is also

regarded as a temporary, pioneer forest type. Old-growth

stands contain many large black willow trees up to 44

inches (112 cm) in d.b.h. and up to 130 feet (40 m) in height

(Lamb 1915, Putnam and Bull 1932). Black willow is a

short-lived species and rarely exceeds 85 years of age. In

fact, most stands begin to break up at around 30 to 55 years

of age as significant mortality occurs (Lamb 1915, Putnam

and others 1960). Openings in old-growth black willow

stands generally support wet-site species and are typically

occupied by green ash, sugarberry, American elm, red

maple, and baldcypress [Taxodium distichum (L.) Rich.]

(Putnam and others 1960).

Typical eastern riverfront forests generally succeed both

eastern cottonwood and black willow forests. These stands

1960, Wiseman 1982). Sweetgum and various water oaks,

such as water, willow (Q. phellos L.), and Nuttall (Q.

nuttallii Palmer) oaks, may be found in the later stages of

stand development (Putnam and others 1960, Sharitz and

Mitsch 1993).

Wiseman (1982) described an old-growth eastern riverfront

forest in the Mississippi Delta that may be regarded as

representative of this forest type. The site is a heavy clay

flat that typically floods to a depth of 3 to 4 feet (0.9 to 1.2

m) for 1 to 3 weeks each year. The overstory is dense and

averages 220 square feet of basal area per acre (50.4 

m ha ) across the area. The overstory is dominated by 2 -1

green ash but also contains significant quantities of

American elm, water hickory, baldcypress, and Nuttall oak.

The stand appears to be in the transition phase between oldgrowth eastern riverfront forest and immature Nuttall oaksweetgum. Evidence for this observation lies in the fact that

the green ash component of the stand has steadily declined

since 1935. Johnson and Price reported that green ash 1

comprised 39 percent of the basal area in 1935 and 34

percent in 1959; Wiseman (1982) found that the green ash

component had dropped to only 31 percent of the basal area

by 1981. Although no ranges of data were given by

Wiseman (1982), average d.b.h. of green ash in the stand in

1981 was 25.8 inches (65.5 cm); average d.b.h. of

apparently younger Nuttall oak found in canopy gaps was

16.1 inches (40.9 cm), thus supporting the notion that this

old-growth stand is gradually breaking up and will

eventually be replaced by a younger stand dominated by

Nuttall oak.

Dead Tree Component

The number of standing snags and the volume of downed

logs in the old-growth stage of eastern riverfront forests

probably vary depending on the specific type of stand and

its location. In general, downed logs likely decompose

rapidly because decay organisms are active under the

prevailing conditions of both high temperature and high

relative humidity. Moreover, frequent flooding probably

Johnson, R.L., Price, T.L. 1959. Final report—resum£ of 20 years of 1

hardwood management on the Delta Purchase Unit. Unpublished report.

On file with: Southern Research Station, Southern Hardwoods Laboratory,

P.O. Box 227, Stoneville, MS 38776.
3

removes much of the downed woody debris from these Martin and Smith (1991) described the understory of an

stands. Although Martin and Smith (1991) reported old-growth eastern riverfront forest in Louisiana as

"several" standing snags and "many" downed logs in an old- dominated primarily by American hornbeam (Carpinus

growth eastern riverfront forest in Louisiana, no other caroliniana Walt.) but with lesser quantities of winged elm

information was found in the literature that quantified the (U. alata Michx.), silverbell (Halesia diptera Ellis),

dead tree component in the old-growth stage of this forest American holly (Ilex opaca Ait.), yaupon (I. vomitoria

type. Ait.), pawpaw [Asimina triloba (L.) Dunal], blueberry

Understory Characteristics

The understory in old-growth eastern riverfront forests is a poison-ivy, common greenbrier, elephant's foot

diverse mixture of small trees, shrubs, seedlings, vines, and (Elephantopus carolinianus Raeusch.), panicum (Panicum

herbaceous vegetation. It may range from sparse to dense, sp.), sedge, violet (Viola sp.), and grapefern (Botrychium

particularly in openings created by dead trees or windthrow. sp.). In general, Martin and Smith (1991) described the

Species composition of the understory also varies with the understory as sparse except under canopy gaps.

type of old-growth forest.

For example, McKnight (1969) reported that the understory

in old-growth eastern cottonwood forests is generally Eastern riverfront forests occur along the margins of both

extremely dense and may be composed of several tree major rivers and minor streams on sites that are seasonally

species, typically dominated by boxelder, red maple, flooded for short periods. Flooding may be deep, as much

sugarberry, red mulberry (Morus rubra L.), and American as 6 to 8 feet (1.8 to 2.4 m) during atypical years, but

elm. Woody vines are also abundant in old-growth eastern generally lasts only 1 to 3 weeks. Soils are young and

cottonwood forests and may restrict tree regeneration, generally have little or no profile development. 

especially in gaps. The most common woody vines and

other vegetation found in the ground cover in old-growth Both eastern cottonwood and black willow become

eastern cottonwood forests are poison-ivy [Toxicodendron established on newly formed sandbars or mud flats and on

radicans (L.) O. Kuntze], grape (Vitis sp.), Virginia creeper newly exposed river margins. Soils range from coarse sand

[Parthenocissus quinquefolia (L.) Planch.], peppervine to fine clay, with eastern cottonwood generally found on

[Ampelopsis arborea (L.) Koehne], blackberry (Rubus sp.), coarse sediments and black willow found on fine sediments.

common greenbrier (Smilax rotundifolia L.), and stinging As further deposition of silt and other sediments occurs on

nettle [Laportea canadensis (L.) Wedd.], also known as these sites and the substrate develops, the cottonwood/

Canada woodnettle (McKnight 1969). willow type is replaced by the riverfront hardwood type,

In the old-growth green ash stand in the Mississippi Delta, drier sites and by green ash, sugarberry, and American elm

Wiseman (1982) found that the sapling and seedling on the wetter sites (Sharitz and Mitsch 1993).

component of the stand was dominated primarily by

sugarberry, American elm, Nuttall oak, and possumhaw Topography is generally the ridge and swale type commonly

(Ilex decidua Walt.). Ground cover was sparse, except in found adjacent to rivers and streams. Both low and high

the larger openings where woody vines, especially cat flats separate the ridges. Eastern riverfront forests occur on

greenbrier (S. glauca Walter), common greenbrier, and all these topographic features; species occurrence depends

trumpetcreeper [Campsis radicans (L.) Seem.], were greatly upon landscape position, soil texture, and soil

abundant. Other woody vines and herbs found in the old- moisture regime.

growth tract included peppervine, smallspike false-nettle

[Boehmeria cylindrica (L.) Swartz], buckwheat vine

(Brunnichia cirrhosa Gaertn.), sedge (Carex sp.), snailseed

[Cocculus carolinsis (L.) DC.], rice cutgrass [Leersia Although species diversity and other measures of richness

oryzoides (L.) Swartz], Japanese honeysuckle (Lonicera are generally expected to increase as forests approach the

japonica L.), Virginia creeper, blackberry, poison-ivy, old-growth stage of stand development, Wiseman (1982)

starjasmine [Trachelospermum difforme (Walter) Gray], reported only moderate diversity and evenness (H'=1.79;

and grape. J'=0.86) in an old-growth eastern riverfront forest in the

(Vaccinium elliottii Chapm.), giant cane [Arundinaria

gigantea (Walter) Muhl.], and grape. Other woody plants

and the major herbs found in the understory included

Soils and Microtopography

dominated by sycamore, pecan, and American elm on the

Other Important Features

Mississippi Delta.
4

Forest Dynamics and Ecosystem Function Representative Old-Growth Stands

The cottonwood/willow forest types represent temporary, Representative old-growth eastern riverfront forests occur at

pioneer stages of forest succession. Because both of these the following two locations:

species require bare mineral soil for establishment, their

natural development is generally restricted to newly C Green Ash Natural Area, Delta National Forest, near

exposed sandbars and mud flats along the margins of rivers Rolling Fork, MS—60 acres (24 ha)

and streams. They both attain their best development along

major rivers in the Lower Mississippi Valley. Because of

their extreme intolerance to shade, neither species is capable

of succeeding itself on these newly formed lands.

Continued natural establishment of these species depends

upon continued formation of new land along major rivers.

However, because many of the rivers within the Lower

Mississippi Valley have been channelized and leveed,

formation of new land has dramatically declined in the

recent past. Natural establishment of new eastern C Big Oak Tree State Park, Mississippi County, Missouri

cottonwood and black willow forests has declined

concomitantly during this same period. Although never

abundant, due to premature logging of these commercially

valuable timber species, old-growth eastern cottonwood and C Cow Shoals, Cleburne County, Arkansas

black willow forests will likely decline in number because

human-caused alterations in the hydrology of major river

systems within the Lower Mississippi Valley prevent

establishment. C Broad River, Chester County, South Carolina

The eastern riverfront forest represents an intermediate

successional stage between the pioneer cottonwood/willow

types and the sweetgum-water oaks (water, willow, and

Nuttall) type on drier sites and the overcup oak-water

hickory type on wetter sites (Putnam and others 1960).

Shelford (1954, 1974) speculated that cottonwood/willow

forests begin to break up at about 35 years of age and are

replaced by eastern riverfront forests by 85 years of age.

The eastern riverfront type lives for about 80 years before

being gradually invaded by sweetgum and water oaks. This

begins about 165 years after initial establishment of the

cottonwood/willow forests on new land and generally lasts

for about 85 years, so that the sweetgum-water oaks type

has replaced the eastern riverfront forest about 250 years

after initial invasion of the site by eastern cottonwood and

black willow. However, Sharitz and Mitsch (1993) pointed

out that repeated disturbances, such as severe flooding or

logging, may allow the eastern riverfront forest type to

persist on the site for several generations over long periods

of time. In the absence of such severe disturbances, the

eastern riverfront forest will soon be replaced by the

sweetgum-water oaks type.

C River Birch Bottom, Kisatchie National Forest, near

Alexandria, LA—9 acres (3.6 ha)

Areas where representative old-growth eastern riverfront

forests may occur include:

C Dardenne Creek, August A. Busch Memorial Wildlife

Area, near Weldon Spring, MO

C Westport Island Natural Area, near Elsberry, MO—480

acres (194 ha)

C Sulphur River Wildlife Management Area, Miller

County, Arkansas
5

Literature Cited

Fenneman, N.M. 1938. Physiography of eastern United States. McGrawHill, New York. 714 p.

Hardin, E.D., K.P. Lewis, and W.A. Wistendahl. 1989. Gradient analysis

of floodplain forests along three rivers in unglaciated Ohio. Bul. of the

Torrey Bot. Club. 116(3):258-264.

Lamb, G.N. 1915. Willows: their growth, use, and importance. U.S. Dep.

Agric. For. Serv. Bul. 316. Washington, DC. 52 p.

Martin, D.L., and L.M. Smith. 1991. A survey and description of the

natural plant communities of the Kisatchie National Forest Winn and

Kisatchie Districts. Louisiana Dep. of Wildl. and Fish., Baton Rouge.

372 p.

McKnight, J.S. 1969. Ecology of four hardwood species. P. 99-116 in The

ecology of southern forests, N.E. Linnartz (ed.). Proc. of the 17th annual

LSU for. symp. Louisiana State Univ. Press, Baton Rouge, LA.

Putnam, J.A. 1951. Management of bottomland hardwoods. U.S. Dep.

Agric. For. Serv. Occasional Pap. 116. 60 p.

Putnam, J.A., and H. Bull. 1932. The trees of the bottomlands of the

Mississippi River Delta Region. U.S. Dep. Agric. For. Serv. Occasional

Pap. 27. 207 p.

Putnam, J.A., G.M. Furnival, and J.S. McKnight. 1960. Management and

inventory of southern hardwoods. U.S. Dep. Agric. Handb. 181. 102 p.

Robertson, P.A., G.T. Weaver, and J.A. Cavanaugh. 1978. Vegetation and

tree species patterns near the northern terminus of the southern

floodplain forest. Ecol. Monogr. 48:249-267.

Sharitz, R.R., and W.J. Mitsch. 1993. Southern floodplain forests. 

P. 311-372 in Biodiversity of the southeastern United States: lowland

terrestrial communities, Martin, W.H., S.G. Boyce, and A.C.

Echternacht (eds.). Wiley, New York.

Shelford, V.E. 1954. Some lower Mississippi Valley floodplain biotic

communities; their age and elevation. Ecology 35:126-142.

Shelford, V.E. 1974. The ecology of North America. Univ. of Illinois

Press, Urbana, IL. 610 p.

Williamson, A.W. 1913. Cottonwood in the Mississippi Valley. U.S. Dep.

Agric. For. Serv. Bul. 24. Washington, DC. 62 p.

Winters, R.K., J.A. Putnam, and I.F. Eldredge. 1938. Forest resources of

the north-Louisiana Delta. U.S. Dep. Agric. For. Serv. Misc. Publ. No.

309. 49 p.

Wiseman, J.B., Jr. 1982. A study of the composition, successional

relationships and floristics of Mississippi River floodplain forests in

parts of Washington, Bolivar, and Sharkey Counties, Mississippi. Ph.D.

Diss., Mississippi State Univ. 268 p.
6

Table 1 (English units)—Standardized table of old-growth attributes for eastern riverfront 

forests

Value Quantifiable __________________ Number

 attribute Range Mean of stands References a

Stand density (no.acre )

-1

—trees $4 in. d.b.h. 32-179 112 3 Williamson 1913

Winters et al. 1938

Wiseman 1982

Stand basal area (ft acre )

2 -1

—trees > 4 in. d.b.h. 160-220 190 2 Robertson et al. 1978

Wiseman 1982

Age of large trees (yrs)b

—all species 58-120 84 9 Hardin et al. 1989

Lamb 1915

Martin and Smith 1991

Putnam and Bull 1932

Williamson 1913

Number of 4-in. size classes

—starting at 4 in. d.b.h. 6-10 8 3 Martin and Smith 1991

Winters et al. 1938

Wiseman 1982

D.b.h. (or maximum d.b.h.)

of largest trees (in)b

—all species 25-72 39 6 Lamb 1915

Martin and Smith 1991

Putnam and Bull 1932

Williamson 1913

Standing snags (no.acre )

-1

—snags > 4 in. d.b.h. Several 1 Martin and Smith 1991

Downed logs (ft acre ) Many Many 1 Martin and Smith 1991 3 -1

Decadent trees (no.acre )

-1 c

—trees > 4 in. d.b.h. 62 62 1 Winters et al. 1938

Number of canopy layers 3+ 3+ 5 Martin and Smith 1991

Putnam and Bull 1932

Wiseman 1982

Percent canopy in gapsd

Other features H'=1.79

 J'=0.86 1 Wiseman 1982

Number of stands may not equal the number of citations. a

Includes dominant and codominant trees that comprise the upper canopy. b

Includes deformed, bole-scarred, spike-topped, and wind-damaged trees. c

 Data unavailable. d
7

Table 1 (metric units)—Standardized table of old-growth attributes for eastern riverfront

forests

Value Quantifiable __________________ Number

 attribute Range Mean of stands References a

Stand density (no.ha )

-1

—trees >10 cm d.b.h. 79-442 277 3 Williamson 1913

Winters et al. 1938

Wiseman 1982

Stand basal area (m ha )

2 -1

—trees >10 cm d.b.h 37-50 44 2 Robertson et al. 1978

Wiseman 1982

Age of large trees (yrs)b

—all species 58-120 84 9 Hardin et al. 1989

Lamb 1915

Martin and Smith 1991

Putnam and Bull 1932

Williamson 1913

Number of 10-cm size classes

—starting at 10 cm d.b.h. 6-10 8 3 Martin and Smith 1991

Winters et al. 1938

Wiseman 1982

D.b.h. (or maximum d.b.h.)

of largest trees (cm)b

—all species 64-183 99 6 Lamb 1915

Martin and Smith 1991

Putnam and Bull 1932

Williamson 1913

Standing snags (no.ha )

-1

—snags >10 cm d.b.h. Several 1 Martin and Smith 1991

Downed logs (m ha ) Many Many 1 Martin and Smith 1991 3 -1

Decadent trees (no.ha )

-1 c

—trees >10 cm d.b.h. 153 153 1 Winters et al. 1938

Number of canopy layers 3+ 3+ 5 Martin and Smith 1991

Putnam and Bull 1932

Wiseman 1982

Percent canopy in gapsd

Other features H'=1.79

 J'=0.86 1 Wiseman 1982

Number of stands may not equal the number of citations. a

 Includes dominant and codominant trees that comprise the upper canopy. b

 Includes deformed, bole-scarred, spike-topped, and wind-damaged trees. c

 Data unavailable. d
Meadows, James S.; Nowacki, Gregory J. 1996. An old-growth definition for eastern riverfront

forests. Gen. Tech. Rep. SRS-4. Asheville, NC: U.S. Department of Agriculture, Forest Service,

Southern Research Station. 7 p.

Eastern riverfront forests fall into one of three types: (1) nearly pure eastern cottonwood stands, 

(2) nearly pure black willow stands, and (3) typical riverfront hardwood stands containing many

species, but generally dominated by sycamore, pecan, green ash, sugarberry, and American elm.

The eastern riverfront forest represents an intermediate successional stage between the pioneer

cottonwood-willow types and the sweetgum-water oaks type on drier sites and the overcup oakwater hickory type on wetter sites. Typical attributes of the living tree component of old-growth

eastern riverfront forests are given, but little quantitative data are available for the dead tree

component of these forests. The understory in old-growth eastern riverfront forests is a diverse

mixture of small trees, shrubs, seedlings, vines, and herbaceous vegetation.

Keywords: Black willow, bottomland hardwood forests, eastern cottonwood, forest dynamics,

pioneer communities, riverfront hardwoods, succession.
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