Forest Resources of the Lower 

Mississippi Alluvial Valley

Sonja N. Oswalt

United States

Department of

Agriculture

Southern 

Research Station

GTR-SRS-177

Forest Service
The Author:

Sonja N. Oswalt is a Forest Resource Analyst with the U.S. Department of 

Agriculture Forest Service, Southern Research Station, Forest Inventory and 

Analysis Research Work Unit, Knoxville, TN 37919.

Southern Research Station

200 W.T. Weaver Blvd. 

Asheville, NC 28804

www.srs.fs.usda.gov

June 2013

Cover Photographs:

From top left: Flooded bottomland hardwood forest in Arkansas (photographer 

unknown, U.S. Fish and Wildlife Service public domain image (http://digitalmedia.

fws.gov/cdm/singleitem/collection/natdiglib/id/12933/rec/4), Diamondback water 

snake on Kisatchie National Forest (photo by Steve Shively, U.S. Forest Service). 

Nuttall oak (Quercus nuttallii, also known as Quercus texana) acorn and branch in 

Mississippi (photo by Dean S. Elsen, U.S. Forest Service Find-a-Photo). On back 

cover: Man with Nuttall oak (Quercus nuttallii, also known as Quercus texana) 

acorns in Mississippi (photo by Dean S. Elsen, U.S. Forest Service Find-a-Photo).
Forest Resources of the Lower Mississippi 

Alluvial Valley

Sonja N. Oswalt

ABSTRACT

At one time, the Lower Mississippi Alluvial Valley was covered by almost 

25 million acres of forest. By the mid-1980s, all that remained of the 

valley’s forested land was roughly 6.6 million acres. This report addresses 

a gap in data about this land by providing, for the first time since 1986, 

comprehensive new estimates of forest area, volume, carbon, and tree 

species stocking change. 

Keywords: Bottomland hardwoods, Forest Inventory and Analysis, Lower 

Mississippi Alluvial Valley, stocking.

INTRODUCTION

The greater Mississippi Alluvial Valley (MAV) extends 

from Cairo, IL, to the confluence of the Mississippi River 

with the Gulf of Mexico in Louisiana. Prior to European 

settlement, forests occupied about 24.7 million acres of 

the MAV landscape (King and others 2006). The historic 

landscape was frequently altered by Native Americans who 

used fire and other techniques to manipulate the forest and 

flush out wildlife (Gardiner and Oliver 2005). The arrival 

of presettlement Europeans introduced diseases that took 

a dramatic toll on Native American populations. With far 

less Native American influence on the forested landscape, 

the MAV forests began to change, and by the time the MAV 

was settled by Europeans in the late 1700s and early 1800s, 

much of the landscape consisted of closed-canopy forest 

(Fredrickson 2005). Settlers began to assert more influence 

over the MAV in the mid- to late-1800s as more people 

migrated from the East to the Great Plains and the west 

coast. These settlers soon recognized the quality of the rich 

soils created through periodic inundation by Mississippi 

floodwaters, particularly in the Lower Mississippi Alluvial 

Valley (LMAV) and the Mississippi Delta. Additionally, 

the value of the Mississippi River and its tributaries for 

transporting lumber was undeniable. Thus, widespread 

clearing for both agricultural production and timber harvest 

coupled to reduce forest land area further (Fredrickson 2005, 

King and others 2005). 

Agricultural production and plantation settlement 

throughout the Delta spurred the need for protection from 

devastating floods. Engineers were trying to tame the mighty 

Mississippi and had already altered hundreds of miles of 

tributaries through levees and channelization efforts when 

the Great Flood of 1927 occurred. Following the devastating 

flood and the passage of the 1928 Flood Control Act, 

unprecedented efforts were made to levee and channelize 

the Mississippi River and nearly all of its tributaries 

(Interagency Floodplain Management Review Committee 

1994). Those efforts were largely successful in decreasing 

flooding and stabilizing the channel of the river—but with 

incalculable impacts to the floodplain environment. The lack 

of periodic flooding meant that nutrients were no longer 

introduced into the soil bed. In some cases, floodwaters that 

escaped the levees became trapped and stagnated, causing 

soils to become hypoxic and hindering tree regeneration. In 

short, the river and its floodplain were disconnected, and as 

a result, ecological functions were disrupted.

Simultaneously, soybean prices began to rise. World War II 

was devastating for China’s soybean production. The United 

States stepped in to fill the gap, and the U.S. soybean crop 

grew from 9 million bushels in 1920 to 78 million bushels 

in 1940 (U.S. Soybean Export Council 2006). The fertile 

soils of the LMAV Delta were ideal for cultivating the bean, 

and farmers were quick to convert forest land to lucrative 

soybean fields. By the 1950s, farmers had realized the 

potential for soy as a cheap protein source in livestock feed 

(U.S. Soybean Export Council 2006). Soybean production 

grew even more, and corn, wheat, and soybean crop prices 

reached all-time highs in the 1960s and 1970s, as U.S. 

soybean industries grew and Japanese soy processing 

industries expanded with imports from the United States 

(U.S. Soybean Export Council 2006). By the time Rudis 

and Birdsey completed their initial study of forest resources 

in the LMAV in the 1980s (using data from the Forest 

Inventory and Analysis (FIA) Program of the U.S. Forest 

Service, U.S. Department of Agriculture), forest area had 

declined from 11.8 million acres to an estimated 6.6 million 

acres (Rudis and Birdsey 1986).

While the 1960s and 1970s were a time of economic growth 

for farms of the LMAV, the 1980s were quite the opposite. 

Rising interest rates resulted in widespread declines in land 

value, and farmers were forced into foreclosure. Since the 

Great Depression, the U.S. government has provided farm 

subsidies to cushion against erratic shifts in supply and 

demand; in the 1980s, new government programs offered 

additional support through conservation incentives to 

farmers willing to convert or revert agricultural land into 

forest or wetland. The Food Security Act of 1985 (Public 

Law 99–198, also called the 1985 Farm Bill) created the 

Swampbuster and Conservation Reserve Programs (CRP). 

The Swampbuster program denied subsidies to farmers who 
2

knowingly converted wetlands to farmland, while the CRP 

offered rental payments and cost-share assistance to farmers 

who voluntarily established “resource conserving cover” 

on eligible land. In many cases, the practice of resource 

conserving cover included allowing fallow fields to revert 

to forest, or establishing forest land on previously farmed 

fields. Similarly, the Wetland Reserve Program (WRP), 

established as part of the 1990 Farm Bill (Public Law 101–

624), offered incentives for farmers who restore, enhance, 

and protect wetlands, including bottomland hardwood 

(BLH) forests, on their marginal cropland.

Along with shifts in governmental programs, there 

emerged in the 1970s and 1980s a renewed concern for the 

environment. Land managers began to see how decades 

of manipulation and exploitation had hurt LMAV land 

resources, including how the loss of forest and wetland 

affected migratory songbird and waterfowl populations, 

and such endangered species as the Louisiana black bear 

(Lower Mississippi Valley Joint Venture Office Forest 

Resource Conservation Working Group 2007). The North 

American Waterfowl Management Plan, developed in 1986, 

called for the establishment of cooperatives to address 

concerns over dwindling wildlife habitat and species. 

To address the habitat needs of at-risk species, Federal 

agencies and nonprofit organizations formed several joint 

venture partnerships, including the Migratory Bird and the 

Lower Mississippi Valley Joint Ventures, both organized 

in 1987. Such partnerships established priority wildlife 

species and habitat objectives, and provided guidance for 

the management of BLH forests and other habitats, with the 

goal of meeting the specified objectives over time. 

Unquestionably, the WRP, CRP, and joint venture programs 

have helped land management agencies, nonprofit 

organizations, and landowners work together in addressing 

LMAV land management priorities. Between 1992 and 

2011, the WRP enrolled 646,672 acres, represented by 1,857 

agreements, in Arkansas, Louisiana, and Mississippi (U.S. 

Department of Agriculture Natural Resources Conservation 

Service 2012). 

Researchers have noted gains in ecosystem services from 

WRP lands (valued at as much as $300 million annually) 

and in afforestation of BLH forests (Jenkins and others 

2010, King and others 2005, Schoenholtz and others 

2001) and much site- and subject-specific research has 

been conducted in the LMAV. However, resource data at 

a regional level has not been updated in a comprehensive, 

consistently collected manner since Rudis and Birdsey 

(1986), which used FIA data collected from 1932 to 1984. 

Our report updates and expands on the work of Rudis 

and Birdsey (1986) and provides current comprehensive 

resource information to professionals, landowners, and 

laypeople with interests in the LMAV.

Figure 1—Map of the Lower Mississippi Alluvial 

Valley as defined by Rudis and Birdsey (1986) and 

used for analysis in this publication. 

METHODS

Study Area

In our report, the LMAV was defined in the same manner 

as in Rudis and Birdsey (1986), and includes counties in 

Arkansas, Louisiana, and Mississippi (fig. 1). Some parishes 

along Louisiana’s gulf coast were either combined or not 

sampled in previous surveys because of the relatively small 

forested acreage within their boundaries; these parishes 

(Plaquemines, St. Bernard, and Jefferson) are not included 

in analyses that compare current estimates to previous 

estimates. The 2010 sample included 1,353 forested or 

partially forested plots. All plots with forest are included 

in the resources estimates in our report, with the exception 

of basal area calculations, which included only plots 

where forested conditions occupied >10 percent of the 

plot (otherwise, over-inflation of values occurs, resulting 

in extreme outliers). Thus, basal area was calculated for 

1,344 plots.

Forest Inventory and Analysis Program in the 

Lower Mississippi Alluvial Valley

The Forest Service has conducted resource inventories since 

the early 1930s, first under the program name of Forest 

Survey, then later (and currently) under the program name 

of Forest Inventory and Analysis. The FIA program has 

evolved over the past 80 years, from a periodic sampling 

regime of surveying forests in each State at about 10-year 
3

Table 1—Reference period and corresponding FIA 

survey date from which data was compiled for each 

State in the analysis

intervals to annual inventories, with numbers compiled 

to produce a “moving average” of estimates from year to 

year. Until about 15 years ago, FIA data were collected 

only on sites considered “productive timberland,” forest 

land capable of producing more than 20 cubic feet of wood 

per acre in a year. This definition of timberland excluded 

reserved land, i.e., any land excluded from timber harvest 

by statute or administrative designation. Plot designs were 

regionally developed and implemented, and varied across 

the country. In the 1980s and 1990s, questions about 

the timeliness, quality, and relevance of the information 

collected in the periodic system led to a series of pilot 

studies that culminated in the inclusion of FIA in the 1998 

Farm Bill (Public Law 105–185). The Farm Bill called 

for the development of a national FIA program with a 

nationally consistent design and a complete, systematic 

annual sample in each State (Bechtold and Patterson 2005). 

The information in this report includes data collected by the 

older (pre-1998) periodic method of collection as well as 

data collected by the current, annual method of collection. 

Appendix B provides details on survey procedures. 

Analysis Years

Statistics for early inventories (1930s through 1960s) were 

obtained from Rudis and Birdsey (1986), Rosson (2001, 

2002), and Rosson and others (1988). Statistics for 1970, 

1980, 1990, and 2010 were calculated from data in the 

FIA database (FIADB) (accessed between June 4, 2012 

and July 24, 2012). Data are publicly available from Miles 

(2012). Table 1 shows the State reporting years that were 

combined to produce decadal estimates; these estimates 

were necessary because historical data were not collected in 

each State in the same year.

Relative Stocking Procedures

The most numerous 20 species for each of two reference 

periods, 1980s and 2010, were selected for relative stocking 

calculations. Lists were combined and duplicates were 

eliminated. Species collected in only one of the two time 

periods were eliminated, as were combined species groups. 

The resulting list consisted of 21 species. Plaquemines, 

St. Bernard, and Jefferson parishes in Louisiana were 

FIA	
  survey	
  date

Reference	
  period Arkansas Louisiana Mississippi

1930 1935 1935 1932

1950 1950 1954 1957

1960 1969 1964 1967

1970 1978 1974 1977

1980 1988 1984 1987

1990 1995 1991 1994

2010 2010 2010 2010

Figure 2—Percent of land area classified as forest by county in 

the Lower Mississippi Alluvial Valley, 2010. 

eliminated from the analysis because they were either 

combined or not surveyed in at least one of the two time 

periods. Stocking values were calculated using the tree 

stocking variable produced in the FIADB, which uses 

species-specific equations developed from normal yield 

tables and stocking charts. The stocking values produced 

are a function of diameter. Relative stocking was calculated 

for each species at the plot level, using equations found in 

Oswalt and others (2008). Mean species-specific average 

annual change was calculated for each county and for the 

entire LMAV, following procedures outlined in Oswalt and 

others (2008).

RESULTS

Forest Area

The LMAV, as defined in our report, encompasses about 

26.7 million acres of total land area. Forests cover about 7.6 

million acres of the land area, and all but 36,000 acres are 

considered available for timber production. Hereafter, the 

word “forest” is used to refer to the timberland portion, and 

the 36,000 acres of reserved land is excluded because of the 

lack of historical data. Therefore, forest area, as described 

in this report, covers 7.6 million acres and accounts for 

28 percent of land area in the LMAV. County-level forest 

cover ranges from < 3 percent to 70 percent, with the least 

forested counties primarily in the northern LMAV adjacent 

the Mississippi River and the coastal parishes of Louisiana 

(fig. 2).
4

Figure 3—Proportion of forest area by forest-type group, Lower 

Mississippi Alluvial Valley. Bottomland hardwood area as defined 

in this publication consists of the oak-gum-cypress and elm-ashcottonwood forest-type groups, combined. 

BLH forests (elm-ash-cottonwood and oak-gum-cypress 

forest-type groups) make up 70 percent (5.2 million acres; 

table 2) of LMAV forest area (fig. 3). The sugarberryhackberry-elm-green ash and sweetgum-Nuttall oak-willow 

oak forest types within those forest-type groups account for 

close to one-half of LMAV bottomland forest acreage, while 

baldcypress-tupelo forests occupy 16 percent. Other foresttype groups found in the LMAV include oak-hickory (17 

percent of forest area), loblolly-shortleaf (7 percent of forest 

area), and various mixed forest-type groups (fig. 3). 

Eighty-two percent of LMAV forest area is privately 

owned. Of the remaining 1.3 million acres, 52 percent is 

owned by State and local governments, 31 percent by the 

U.S. Fish and Wildlife Service, and the remainder by other 

Federal agencies. 

Naturally regenerated stands constitute 6.7 million acres 

(89 percent) of forest area. Planted acreage makes up 

almost one-half of all loblolly-shortleaf pine forest area, 

and loblolly-shortleaf pine constitutes 43 percent of all 

LMAV planted forest area, with 353,069 ± 82,971 acres. 

BLH forests also account for 43 percent of planted forest, or 

355,475 ± 121,210 acres. Most planted forest (88 percent) is 

privately owned.

Sixty-three percent (4.8 million acres) of all LMAV forest 

area consists of large diameter stands (stands predominately 

stocked with softwoods ≥ 9.0 inches diameter at breast 

height (d.b.h.) or hardwoods ≥ 11.0 d.b.h. (fig. 4). An even 

larger proportion (70 percent) of BLH forest area consists 

of large diameter stands, with just 16 percent of area in the 

small diameter size class (stands predominately stocked with 

trees < 5.0 inches d.b.h.).

Figure 3—Proportion of forest area by forest-type group, Lower Mississippi 

Alluvial Valley. Bottomland hardwood area as defined in this publication 

consists of the oak-gum-cypress and elm-ash-cottonwood forest-type groups, 

combined.

Oak-gumcypress

41%

Other eastern

softwoods

<1%

Other hardwoods

<1%

Elm-ashcottonwood

29%

Exotic hardwoods

1%

Nonstocked

3%

Loblolly-shortleaf

7%

Oak-pine

2%

Oak-hickory

17%

Figure 4—Forest area by forest-type group and stand-size class, 

Lower Mississippi Alluvial Valley, 2010. 

Forest-type group

Loblollyshortleaf

Other eastern

softwoods

Oakpine

Oakhickory

Oak-gumcypress

Elm-ashcottonwood

Other

hardwoods

Exotic

hardwoods

Area (thousand acres)

0

500

1,000

1,500

2,000

2,500 Small diameter

Medium diameter 

Large diameter

Figure 4—Forest area by forest-type group and stand-size class, Lower 

Mississippi Alluvial Valley, 2010.

Trends in Forest Area 1930–2010

During the 1930 reference period, forest area was estimated 

at 11.8 million acres, 89 percent of which was BLH. From 

the 1930s to 2010, forest area declined by a net 37 percent. 

Most deforestation occurred between 1930 and 1980, when 

forest area declined by 45 percent. The last three decades 

(from 1990 to 2010) have shown gradual increases in overall 

forest cover, including bottomland hardwood forests, though 

the proportion of forest area considered BLH has continued 

to decrease (fig. 5). In other words, while BLH forest area is 

increasing, it is not increasing at a rate proportional with the 

remainder of forest land (fig. 6), and most of the lag appears 

to be in the oak-gum-cypress forest-type group. In contrast, 

the proportion of forest area classified as loblolly-shortleaf 

has increased by a little over 4 percent since the 1970s, and 

the proportion of forest classed as oak-hickory has increased 

by about 2 percent between the 1970 and 1980 surveys.

County-level gains and losses are more complex. Countylevel estimates were available only from 1950 through the 

present, and some coastal parishes were not measured or 

were combined in early surveys because of the relatively 

small area of forest they contained. From 1950 to 1980, the 

largest measured loss of forest area (92 percent) occurred 

in the West Carroll Parish of Louisiana, converting that 

parish’s land cover from 45-percent forested in 1950 

to 8-percent forested in 1980; currently, the parish is 

18-percent forested. Conversely, St. Mary Parish in 

Louisiana experienced an increase from 27-percent forested 

in 1950 to 34-percent forested in 1980, finally measuring 

at 39-percent forested in 2010. Table 3 contains detailed 

county area estimates from 1950 through 2010, while figure 

7 (A, B, and C) shows gains and losses from 1950 to 1980 

and from 1980 to 2010, as well as overall change from 1950 

to 2010.
5

Table 2—Forest area by forest-type group and forest type, 2010

Forest-­‐type	
  group Forest-­‐type Forest	
  area	
  

acres

Loblolly/shortleaf	
  pine Loblolly	
  pine 532,800

Loblolly/shortleaf	
  pine Shortleaf	
  pine 12,200

Loblolly/shortleaf	
  pine	
  Total 545,000

Other	
  eastern	
  softwoods Eastern	
  redcedar 4,100

Oak/pine Eastern	
  redcedar/hardwood 18,900

Oak/pine Shortleaf	
  pine/oak 19,300

Oak/pine Loblolly	
  pine/hardwood 126,800

Oak/pine	
  Total 165,000

Oak/hickory Post	
  oak/blackjack	
  oak 106,900

Oak/hickory White	
  oak/red	
  oak/hickory 406,500

Oak/hickory White	
  oak	
   32,500

Oak/hickory Yellow-­‐poplar/white	
  oak/northern	
  red	
  oak 18,700

Oak/hickory Sassafras/persimmon 65,200

Oak/hickory Sweetgum/yellow-­‐poplar 214,700

Oak/hickory Yellow-­‐poplar 2,300

Oak/hickory Black	
  locust 3,700

Oak/hickory Chestnut	
  oak/black	
  oak/scarlet	
  oak 2,800

Oak/hickory Cherry/white	
  ash/yellow-­‐poplar 20,500

Oak/hickory Elm/ash/black	
  locust 91,800

Oak/hickory Red	
  maple/oak 9,700

Oak/hickory Mixed	
  upland	
  hardwoods 284,200

Oak/hickory	
  Total 1,259,500

Oak/gum/cypress Swamp	
  chestnut	
  oak/cherrybark	
  oak 181,300

Oak/gum/cypress Sweetgum/Nuttall	
  oak/willow	
  oak 1,267,400

Oak/gum/cypress Overcup	
  oak/water	
  hickory 571,400

Oak/gum/cypress Baldcypress/water	
  tupelo 863,500

Oak/gum/cypress Sweetbay/swamp	
  tupelo/red	
  maple 179,000

Oak/gum/cypress Baldcypress/pondcypress 200

Oak/gum/cypress	
  Total 3,062,800

Elm/ash/cottonwood River	
  birch/sycamore 102,900

Elm/ash/cottonwood Cottonwood 55,500

Elm/ash/cottonwood Willow 226,600

Elm/ash/cottonwood Sycamore/pecan/American	
  elm 415,500

Elm/ash/cottonwood Sugarberry/hackberry/elm/green	
  ash 1,286,800

Elm/ash/cottonwood Red	
  maple/lowland 43,400

Elm/ash/cottonwood Cottonwood/willow 50,700

Elm/ash/cottonwood	
  Total 2,181,400

Other	
  hardwoods Other	
  hardwoods 10,400

Exotic	
  hardwoods Other	
  exotic	
  hardwoods 111,800

Nonstocked Nonstocked 202,400

Total 7,542,500
6

Figure 6—Proportion of bottomland hardwoods relative to total forest 

area by year, Lower Mississippi Alluvial Valley. 

Year

1930 1950 1960 1970 1980 1990 2010

Area (percent of total)

0

20

40

60

80

100

Figure 6—Proportion of bottomland hardwoods relative to total forest

area by year, Lower Mississippi Alluvial Valley.

Since 1980, there has been a slight increase in the proportion 

of small-diameter stands, and subsequent slight decrease 

in the proportion of large-diameter stands, with the area 

of forest considered small diameter increasing from 12 

percent to 18 percent, and the area considered large diameter 

decreasing from 69 to 63 percent (fig. 8). This finding is 

consistent with an increase in planted acreage, particularly 

loblolly pine and some BLH.

Change matrices are used to examine remeasured plots 

in the FIA inventory. The matrices are useful in tracking 

reversions of agricultural land to forest land as well as 

diversions of forest land to agricultural land, and thus in 

understanding how changes in land can affect forest area. 

The sample used to develop a change matrix only includes 

plots measured at time one and time two. In the LMAV, 

for the indicated 2000 and 2010 reference periods, 89 

percent of current forest area was previously forested, while 

nearly 9 percent of current forest area was previously in an 

agricultural land use. Other land uses (development, water, 

and wetland) individually contributed < 1 percent to current 

forest area estimates. In contrast, about 1.3 percent of land 

area previously forested was diverted to agricultural uses, 98 

percent of area previously forested remained forested, and 

about 1 percent of area previously forested was diverted to 

other land uses (development, water, and wetland). In other 

words, reverted agricultural land is contributing to forest 

area growth in the LMAV, but diversions to agriculture are 

the largest detractions from that overall gain.

Forest Composition

Red maple (Acer rubrum) was the most abundant LMAV 

species in 2010, with an estimated 339 (± 62) million trees 

(111 ± 20 trees/ha), although sweetgum (Liquidambar 

styraciflua) occurred on more plots. Fewer sweetgum 

seedlings relative to red maple seedlings persist in the 

LMAV, a finding that explains the discrepancy between 

distribution across plots and abundance estimates of red 

maple and sweetgum. Red maple accounts for 10 percent 

of the entire estimated tree population in the LMAV. By 

comparison, it constituted 13 percent of the estimated tree 

population in the 1980s, with an average of 127 trees/

ha. Listed in order of frequency, sweetgum, sugarberry 

(Celtis laevigata), green ash (Fraxinus pennsylvanica), 

and winged elm (Ulmus alata) were also among the most 

commonly detected species in the 2010 reference period 

(fig. 9). Sugarberry, sweetgum, green ash, and water tupelo 

(Nyssa aquatica) were among the most abundant species 

in the 1980 survey, following red maple (fig. 10). Although 

water tupelo was among the top five most abundant species 

in 1980, by 2010 it was no longer listed among the top 10 

most abundant species, overshadowed by loblolly pine 

(Pinus taeda), water oak (Quercus nigra), American elm 

(U. americana), Chinese tallowtree (Triadica sebifera), 

boxelder (A. negundo), and eastern hophornbeam (Ostrya 

virginiana) (fig. 11). 

Species composition in BLH forests in 2010 mirrored the 

composition across the entire LMAV. Red maple was most 

abundant, followed by sugarberry, green ash, sweetgum, 

and winged elm. Water tupelo and baldcypress (Taxodium 

distichum) were the eighth and ninth most abundant species 

in BLH forests. In contrast, they were fourth and fifth most 

abundant in BLH forests in 1980. 

Loblolly pine was the most abundant species on planted 

forests, with an estimated 123.2 ± 39.4 million trees. 

Sixty-five percent of the estimated loblolly pine population 

occurred on sites with evidence of artificial regeneration. 

Sweetgum, winged elm, green ash, and water oak were the 

next most abundant, but the number of loblolly pine trees 

on planted forests is almost four times that of sweetgum. 

Coupled with the area estimates of planted forests by foresttype group (table 4), these numbers suggest that planted 

BLH forests are being populated with a diversity of species, 

while upland plantations consist primarily of loblolly pine. 

Figure 5—Forest area (total and bottomland hardwoods) by 

year, Lower Mississippi Alluvial Valley. 

Year

1930 1950 1960 1970 1980 1990 2010

Area (million acres)

0

2

4

6

8

10

12

14 Total

Bottomland hardwood 

Figure 5—Forest area (total and bottomland hardwoods) by year, Lower 

Mississippi Alluvial Valley.
7

Table 3—Total land and forest area estimates in the Lower Mississippi Alluvial Valley by county and 

reference period

Forest area

State County

Total land 

area 1950 1970 1980 1990 2010

thousand acres

Arkansas Arkansas 596.0 270.7 206.5 190.7 228.5 191.5

Arkansas Chicot 423.7 193.8 67.8 83.7 71.3 122.6

Arkansas Clay 411.8 201.9 68.4 78.5 79.3 70.8

Arkansas Craighead 458.3 113.8 48.2 49.0 66.0 57.9

Arkansas Crittenden 373.8 81.7 35.7 21.0 44.4 38.6

Arkansas Cross 353.0 157.9 41.3 48.1 45.1 50.0

Arkansas Desha 455.3 244.5 153.0 150.8 152.8 151.4

Arkansas Greene 364.7 119.0 50.4 55.7 71.4 102.7

Arkansas Jackson 451.5 146.0 53.3 63.3 68.8 71.9

Arkansas Jefferson 603.8 244.0 213.2 218.8 218.4 198.0

Arkansas Lawrence 404.4 136.0 83.7 84.6 93.4 84.9

Arkansas Lee 384.3 157.0 87.9 98.4 87.3 91.3

Arkansas Lincoln 334.6 165.0 135.3 153.2 150.8 142.7

Arkansas Lonoke 506.7 180.0 78.5 75.8 122.4 116.4

Arkansas Mississippi 562.0 73.0 20.9 26.3 33.1 28.9

Arkansas Monroe 394.1 214.0 145.8 140.4 138.4 174.8

Arkansas Phillips 459.5 168.0 88.1 94.4 105.8 94.6

Arkansas Poinsett 494.0 172.0 42.9 54.9 56.5 67.8

Arkansas Prairie 407.6 183.0 76.3 77.6 109.9 105.8

Arkansas St. Francis 388.6 119.0 62.9 67.1 80.3 79.8

Arkansas Woodruff 381.8 156.0 68.6 63.9 87.0 114.6

Louisiana Acadia 438.0 81.5 66.6 82.1 75.9 120.9

Louisiana Ascension 197.0 94.6 97.2 84.9 90.4 78.8

Louisiana Assumption 202.1 133.0 139.1 144.0 128.5 107.2

Louisiana Avoyelles 581.0 321.0 240.4 166.2 147.3 268.4

Louisiana Catahoula 420.1 364.0 202.6 177.0 157.9 183.9

Louisiana Concordia 436.1 353.0 218.4 151.0 151.1 195.9

Louisiana East Carroll 296.0 147.0 52.2 64.8 43.4 58.3

Louisiana Franklin 412.4 166.0 67.2 72.9 89.3 88.5

Louisiana Iberia 324.4 118.0 122.5 149.1 115.4 89.6

Louisiana Iberville 422.1 274.0 279.8 280.2 277.4 293.3

Louisiana Lafayette 180.2 13.0 7.8 5.1 12.7 21.5

Louisiana Lafourche 624.6 151.0 177.2 143.7 114.1 83.7

Louisiana Madison 384.2 296.0 167.8 104.6 118.8 140.7

Louisiana Morehouse 532.2 343.0 200.7 188.7 181.6 216.8

Louisiana Pointe Coupee 360.6 204.0 153.2 142.1 134.6 178.2

Louisiana Richland 348.5 154.0 86.4 32.4 74.5 67.8

Louisiana St. Charles 172.6 64.0 76.9 58.8 53.5 82.0

Louisiana St. James 152.0 85.0 86.2 79.3 79.1 80.2

Louisiana St. John the Baptist 135.7 85.0 99.2 96.0 76.9 59.8

Louisiana St. Landry 639.9 266.0 220.8 188.8 164.7 225.7

Louisiana St. Martin 402.7 312.0 304.2 305.4 315.5 253.5

Louisiana St. Mary 414.2 112.0 148.7 139.4 124.4 162.4

Louisiana Tensas 389.1 246.0 162.5 114.0 116.4 134.0

Louisiana Terrebonne 598.7 111.0 112.8 104.8 71.3 80.1

Louisiana Vermilion 772.4 – 15.5 10.3 25.3 26.1

Louisiana West Baton Rouge 130.2 71.4 62.0 52.5 49.2 50.5

continued
8

Table 3—(continued) Total land and forest area estimates in the Lower Mississippi Alluvial Valley by 

county and reference period

— = no sample.

Louisiana Vermilion 772.4 – 15.5 10.3 25.3 26.1

Louisiana West Baton Rouge 130.2 71.4 62.0 52.5 49.2 50.5

Louisiana West Carroll 227.2 101.6 19.8 8.1 12.4 40.4

Louisiana West Feliciana 286.7 182.8 163.3 158.6 168.5 183.1

Mississippi Bolivar 591.3 108.0 96.3 66.3 84.8 128.6

Mississippi Coahoma 362.2 94.0 69.8 56.6 67.9 70.4

Mississippi Holmes 491.2 223.0 220.1 255.9 269.7 342.2

Mississippi Humphreys 279.8 101.0 38.4 41.8 36.3 53.1

Mississippi Issaquena 269.9 161.0 120.5 98.4 116.5 117.2

Mississippi Leflore 362.2 94.0 69.2 57.9 63.5 75.7

Mississippi Quitman 262.0 64.0 35.3 32.5 26.5 38.0

Mississippi Sharkey 290.5 132.0 82.6 72.7 92.8 115.9

Mississippi Sunflower 436.3 49.0 30.2 32.3 38.1 13.9

Mississippi Tallahatchie 406.8 151.0 127.6 97.2 114.0 136.5

Mississippi Tunica 279.6 91.0 52.4 57.8 44.6 68.8

Mississippi Warren 360.0 233.2 235.8 215.5 253.6 253.7

Mississippi Washington 446.0 108.0 65.8 65.7 71.8 54.0

Mississippi Yazoo 597.1 307.0 232.5 241.6 263.5 295.2

Just because a species occurs in an area with clear evidence 

of artificial regeneration according to FIA data, that 

species was not necessarily planted but instead may have 

been recruited into the ecological community prior to or 

following artificial regeneration.

Diameter distributions of baldcypress and water tupelo 

are of interest because of concerns about the impacts of 

altered hydrologic regimes on regeneration. The diameter 

distributions of both of these species in the 2010 survey 

show that there has been a recent “flush” of saplings in the 

1- to 3-inch diameter class (figs. 12 and 13). This suggests 

that a discrete event or a series of events may have resulted 

in disturbances that initiated new growth. Given that the 

data used for this analysis were collected from 2005 through 

2010, Hurricanes Katrina and Rita might be influences 

in the flush of new growth. Diameter distributions in the 

1980s do not show the same type of distribution pattern, 

but rather reflect a reverse “J” curve typical of large-scale 

inventory diameter distributions. This increase in the 

number of seedlings in the small diameter classes is of 

interest given current research regarding declining LMAV 

cypress regeneration, specifically the Atchafalaya Basin 

(Faulkner and others 2009). Other species that show this 

bimodal distribution include loblolly pine, extensively 

planted in recent years; river birch (Betula nigra), a 

frequent colonizer of disturbed sites; pignut hickory (Carya 

glabra); waterlocust (Gleditsia aquatica); American 

sycamore, (Platanus occidentalis) to a small degree; swamp 

chestnut oak (Q. michauxii); and black locust (Robinia 

pseudoacacia). With some of these species, sample size may 

drive the diameter distribution pattern, i.e., the sample for a 

species is too small to accurately capture the distribution of 

the population (e.g., pignut hickory, rare in the LMAV). 

Tree size is an important consideration in the management 

of wildlife habitat, timber species, aesthetics, and water 

quality issues on LMAV forest land. There are an estimated 

14.7 million trees ≥ 25 inches d.b.h. on forests in the LMAV, 

or < 1 percent of the total estimated population of 3.4 billion 

live trees. 

Species Volume

Baldcypress contributes the largest volume/ha of all species 

at 16 ± 3 m3/ha (233.2 ± 40 cubic feet per acre). Sweetgum, 

water tupelo, green ash, and sugarberry contribute the next 

largest volumes with 12 ± 2, 10 ± 3, 8 ± 1, and 8 ± 1 m3/ha 

(176.8 ± 26.3, 136.8 ± 35.4, 121.0 ± 17.8, and 113.1 ± 15.5 

cubic feet per acre), respectively (table 5). Red maple, while 

the most abundant species, contributes about 3 ± 0.6 m3/ha 

(45.5 ± 9 cubic feet per acre) of volume.

Forest area

State County

Total land 

area 1950 1970 1980 1990 2010

thousand acres

Arkansas Arkansas 596.0 270.7 206.5 190.7 228.5 191.5

Arkansas Chicot 423.7 193.8 67.8 83.7 71.3 122.6

Arkansas Clay 411.8 201.9 68.4 78.5 79.3 70.8

Arkansas Craighead 458.3 113.8 48.2 49.0 66.0 57.9

Arkansas Crittenden 373.8 81.7 35.7 21.0 44.4 38.6

Arkansas Cross 353.0 157.9 41.3 48.1 45.1 50.0

Arkansas Desha 455.3 244.5 153.0 150.8 152.8 151.4

Arkansas Greene 364.7 119.0 50.4 55.7 71.4 102.7

Arkansas Jackson 451.5 146.0 53.3 63.3 68.8 71.9

Arkansas Jefferson 603.8 244.0 213.2 218.8 218.4 198.0

Arkansas Lawrence 404.4 136.0 83.7 84.6 93.4 84.9

Arkansas Lee 384.3 157.0 87.9 98.4 87.3 91.3

Arkansas Lincoln 334.6 165.0 135.3 153.2 150.8 142.7

Arkansas Lonoke 506.7 180.0 78.5 75.8 122.4 116.4

Arkansas Mississippi 562.0 73.0 20.9 26.3 33.1 28.9

Arkansas Monroe 394.1 214.0 145.8 140.4 138.4 174.8

Arkansas Phillips 459.5 168.0 88.1 94.4 105.8 94.6

Arkansas Poinsett 494.0 172.0 42.9 54.9 56.5 67.8

Arkansas Prairie 407.6 183.0 76.3 77.6 109.9 105.8

Arkansas St. Francis 388.6 119.0 62.9 67.1 80.3 79.8

Arkansas Woodruff 381.8 156.0 68.6 63.9 87.0 114.6

Louisiana Acadia 438.0 81.5 66.6 82.1 75.9 120.9

Louisiana Ascension 197.0 94.6 97.2 84.9 90.4 78.8

Louisiana Assumption 202.1 133.0 139.1 144.0 128.5 107.2

Louisiana Avoyelles 581.0 321.0 240.4 166.2 147.3 268.4

Louisiana Catahoula 420.1 364.0 202.6 177.0 157.9 183.9

Louisiana Concordia 436.1 353.0 218.4 151.0 151.1 195.9

Louisiana East Carroll 296.0 147.0 52.2 64.8 43.4 58.3

Louisiana Franklin 412.4 166.0 67.2 72.9 89.3 88.5

Louisiana Iberia 324.4 118.0 122.5 149.1 115.4 89.6

Louisiana Iberville 422.1 274.0 279.8 280.2 277.4 293.3

Louisiana Lafayette 180.2 13.0 7.8 5.1 12.7 21.5

Louisiana Lafourche 624.6 151.0 177.2 143.7 114.1 83.7

Louisiana Madison 384.2 296.0 167.8 104.6 118.8 140.7

Louisiana Morehouse 532.2 343.0 200.7 188.7 181.6 216.8

Louisiana Pointe Coupee 360.6 204.0 153.2 142.1 134.6 178.2

Louisiana Richland 348.5 154.0 86.4 32.4 74.5 67.8

Louisiana St. Charles 172.6 64.0 76.9 58.8 53.5 82.0

Louisiana St. James 152.0 85.0 86.2 79.3 79.1 80.2

Louisiana St. John the Baptist 135.7 85.0 99.2 96.0 76.9 59.8

Louisiana St. Landry 639.9 266.0 220.8 188.8 164.7 225.7

Louisiana St. Martin 402.7 312.0 304.2 305.4 315.5 253.5

Louisiana St. Mary 414.2 112.0 148.7 139.4 124.4 162.4

Louisiana Tensas 389.1 246.0 162.5 114.0 116.4 134.0

Louisiana Terrebonne 598.7 111.0 112.8 104.8 71.3 80.1

Louisiana Vermilion 772.4 – 15.5 10.3 25.3 26.1

Louisiana West Baton Rouge 130.2 71.4 62.0 52.5 49.2 50.5
9

Figure 7—(A) Gains and losses in Lower Mississippi Alluvial Valley 

forest land from 1950 to 1980 by county, (B) Gains and losses in 

Lower Mississippi Alluvial Valley forest land from 1980 to 2010 by 

county, (C) Gains and losses in Lower Mississippi Alluvial Valley 

forest land from 1950 to 2010 by county. 

Louisiana

Arkansas

Tennessee

Mississippi

>50 loss

-0.50 – -0.25

-0.25 – 0.0

0.0 – 0.25

0.25 – 0.50

0.50 – 0.75

1980–2010

Change in forest area (percent)

Figure 7b—Gains and losses in Lower Mississippi Alluvial Valley forest land from 1980 to 

2010 by county.

>50 loss

-0.50 – -0.25

-0.25 – 0.0

0.0 – 0.25

0.25 – 0.50

0.50 – 0.75

1950–2010

Change in forest area (percent)

Figure 7c—Gains and losses in Lower Mississippi Alluvial Valley forest land from 1950 to 

2010 by county.

Louisiana

Arkansas

Tennessee

Mississippi

(A)

(B)

(C)

Mississippi

Tennessee

Arkansas

Louisiana
10

Figure 9—Number of live trees on forest land (± 95 percent 

confidence interval) by species, Lower Mississippi Alluvial Valley, 

2010.

Figure 10—Number of live trees (± 95 percent confidence interval) 

on forest land by species, Lower Mississippi Alluvial Valley, 1980. 

Species

Red maple Sweetgum

Sugarberry Green ash

Winged elm

Loblolly pine Water oak

American elm Chinese tallowtree Boxelder Eastern hophornbeam Water tupelo Common persimmon Baldcypress

Black willow

Water hickory Water-elm, planertree Slippery elm American hornbeam, musclewood Nuttall oak

Number of trees (million)

0

100

200

300

400

500

Figure 9—Number of live trees on forest land (± 95 percent confidence 

interval) by species, Lower Mississippi Alluvial Valley, 2010.

Species

Number of trees (million)

0

100

200

300

400

500

Red maple

Sugarberry Sweetgum Green ash

Loblolly pine

Winged elm

Water oak

American elm

Willow oak

Boxelder

Eastern hophornbeam

Water tupelo

Common persimmon

Baldcypress

Willow spp.

Water hickory

Flowering dogwood

Hickory spp.

American hornbeam, musclewood Overcup oak

Figure 10—Number of live trees (± 95 percent confidence interval) on 

forest land by species, Lower Mississippi Alluvial Valley, 1980.

Year

1980 2010

Area (percent)

0

20

40

60

80

100

Small diameter 

Medium diameter 

Large diameter 

Nonstocked 

Figure 8—Proportion of forest area by stand-size class and year, Lower 

Mississippi Alluvial Valley.

Figure 8—Proportion of forest area by stand-size class and year, 

Lower Mississippi Alluvial Valley. 
11

Number of trees (per acre)

Species

Red maple

Sweetgum

Sugarberry

Green ash

Winged elm

Loblolly pine

Water oak

American elm

Boxelder

Eastern hophornbeam

Water tupelo

Common persimmon

Baldcypress

Water hickory

Water-elm, planertree

Slippery elm

American hornbeam, musclewood

Nuttall oak

Flowering dogwood

Overcup oak

White oak

Blackgum

Willow oak

Hawthorn spp.

Cherrybark oak

American sycamore

Pecan

1980

2010

0 10 20 30 40 50 60

Figure 11—Number of trees per acre for the most common species by year, Lower Mississippi Alluvial 

Figure 11—Number of trees per acre for the most common species by year, Lower Mississippi Alluvial Valley, Valley, 1980 and 2010.

1980 and 2010. 

Table 4—Forest area in the Lower Mississippi Alluvial Valley by forest-type group and stand origin, 2010

— = no sample.

Stand origin

Forest type group Total forest 

area

Total forest 

area 95% 

confidence 

interval

Natural 

stands

Natural 

stands 95% 

confidence 

interval

Clear 

evidence of 

artificial 

regeneration

Clear 

evidence of 

artificial 

regeneration 

95% 

confidence 

interval

Total 7,542,521 193,089 6,717,925 182,728 824,595 127,977

Loblolly/shortleaf pine 544,994 99,843 191,925 61,531 353,069 82,971

Other eastern softwoods 4,093 8,268 4,093 8,268 – –

Oak/pine 164,945 58,193 121,075 49,253 43,870 31,621

Oak/hickory 1,259,567 145,606 1,222,714 143,302 36,853 27,809

Oak/gum/cypress 3,062,865 207,050 2,805,310 194,127 257,555 74,639

Elm/ash/cottonwood 2,181,422 190,220 2,083,503 184,598 97,920 46,571

Other hardwoods 10,400 14,710 10,400 14,710 – –

Exotic hardwoods 111,798 49,012 111,798 49,012 – –

Nonstocked 202,436 60,123 167,108 53,775 35,328 27,104
12

--

Diameter class

1.0–2.9

3.0–4.9

5.0–6.97.0–8.9

9.0–10.9

11.0–12.913.0–14.9

15.0–16.9

17.0–18.9

19.0–20.921.0–22.9

23.0–24.9

25.0–26.9

27.0–28.9

29.0–30.931.0–32.9

33.0–34.935.0–36.9

37.0–38.939.0–40.9

41+

Number of trees (million)

0

5

10

15

20

25

30

1980 

2010 

--

Figure 12—Number of live water tupelo trees (± 95 percent confidence interval) by diameter class and 

year, Lower Mississippi Alluvial Valley.

Figure 13—Number of live baldcypress trees (± 95 percent confidence interval) by diameter class 

and year, Lower Mississippi Alluvial Valley.

Figure 12—Number of live water tupelo trees (± 95 percent confidence interval) by diameter class and 

year, Lower Mississippi Alluvial Valley. 

Figure 13—Number of live baldcypress trees (± 95 percent confidence interval) by diameter class and year, 

Lower Mississippi Alluvial Valley.

Diameter class

Number of trees (million)

0

5

10

15

20

25

30

35

40 1980 

2010 

1.0–2.9

3.0–4.9

5.0–6.97.0–8.9

9.0–10.9

11.0–12.913.0–14.9

15.0–16.917.0–18.9

19.0–20.921.0–22.923.0–24.9

25.0–26.9

27.0–28.9

29.0–30.931.0–32.9

33.0–34.935.0–36.9

37.0–38.9

39.0–40.9

41+
13

Table 5—Per-acre volumes by species in the Lower Mississippi Alluvial Valley, 2010

Species Volume 

95% 

confidence 

interval Species Volume 

95% 

confidence 

interval

cubic feet 

per acre

cubic feet 

per acre

White ash 3.3 1.7

Baldcypress 233.2 39.6 Waterlocust 3.0 1.5

Sweetgum 176.8 26.3 Hackberry 2.9 2.7

Water tupelo 136.8 35.4 Florida maple 2.8 1.7

Green ash 121.0 17.8 American hornbeam, musclewood 2.8 0.9

Sugarberry 113.1 15.5 Silver maple 2.5 2.1

Loblolly pine 102.3 22.5 Willow spp. 2.5 2.2

Overcup oak 87.1 18.9 Bitternut hickory 2.4 1.2

Water oak 79.6 19.3 Sassafras 2.0 1.3

Texas red oak 69.6 15.0 Eastern hophornbeam 2.0 0.6

Black willow 59.6 14.0 Delta post oak 1.6 2.0

Willow oak 55.8 13.6 Live oak 1.5 1.1

Water hickory 54.4 11.6 Chinkapin oak 1.4 1.3

American elm 48.8 8.6 Carolina basswood 1.0 1.0

Cherrybark oak 48.3 12.5 Cucumbertree 0.9 1.0

Red maple 45.5 9.2 Black walnut 0.9 0.8

Pecan 35.8 11.7 Red mulberry 0.8 0.5

White oak 31.8 8.7 Black locust 0.8 0.8

Eastern cottonwood 29.5 11.9 Flowering dogwood 0.8 0.4

American sycamore 29.0 9.4 Chinaberry 0.7 0.8

Southern red oak 27.2 8.8 Swamp white oak 0.5 0.8

Boxelder 23.7 5.2 Cottonwood and poplar spp. 0.5 0.8

Post oak 20.1 7.0 American basswood 0.5 0.7

Slippery elm 13.9 3.7 Blackjack oak 0.4 0.5

Honeylocust 12.6 4.2 Spruce pine 0.4 0.8

Mockernut hickory 11.6 3.7 River birch 0.4 0.5

Winged elm 11.0 2.5 Nutmeg hickory 0.3 0.7

Yellow-poplar 10.8 4.6 Eastern redbud 0.3 0.2

Pignut hickory 9.9 3.9 Southern magnolia 0.3 0.3

American beech 9.3 4.3 Bigleaf magnolia 0.3 0.5

Chinese tallowtree 8.5 3.3 Netleaf hackberry 0.3 0.5

Shortleaf pine 8.4 4.7 Carolina ash 0.2 0.5

Shagbark hickory 8.0 3.5 Chittamwood, gum bumelia 0.2 0.4

Cedar elm 7.9 4.1 Southern redcedar 0.2 0.4

Shumard oak 7.6 3.7 Sourwood 0.2 0.3

Common persimmon 7.5 1.9 Redbay 0.2 0.2

Black oak 6.2 3.3 Shellbark hickory 0.2 0.4

Swamp chestnut oak 6.1 2.9 Hawthorn spp. 0.2 0.1

Blackgum 5.8 2.3 American holly 0.1 0.2

Water-elm, planertree 5.2 2.2 Paulownia, empress-tree 0.1 0.1

Northern red oak 4.6 2.5 Pondcypress 0.1 0.2

Laurel oak 4.5 4.4 Sand hickory 0.1 0.2

Black hickory 4.5 1.7 Sweetbay 0.1 0.1

Black cherry 4.0 1.3 Osage-orange 0.1 0.1

Eastern redcedar 4.0 1.9 Southern catalpa 0.1 0.1

Swamp tupelo 3.7 3.0 Pawpaw 0.1 0.1

Total 1,847.4 85.0
14

Figure 15—Mean per-acre baldcypress basal area by county in the Lower Mississippi 

Alluvial Valley, 2010.

!

!

!

!

!

Basal area

square feet 

per acre

Louisiana

Arkansas

Tennessee

Mississippi

<25

25–75

75–125

125–200

>200

Basal area

square feet 

per acre

!

!

!

!

!

Louisiana

Arkansas

Tennessee

Mississippi

Figure 14—Mean per-acre basal area by county in the Lower Mississippi Alluvial Valley, 

2010.

<25

25–75

75–125

125–200

>200

Figure 14—Mean per-acre basal area by county in the 

Lower Mississippi Alluvial Valley, 2010. 

Figure 15—Mean per-acre baldcypress basal 

area by county in the Lower Mississippi Alluvial 

Valley, 2010. 
15

!

!

!

!

!

Basal area

square feet 

per acre

Louisiana

Arkansas

Tennessee

Mississippi

<25

25–75

75–125

125–200

>200

Figure 16—Mean per-acre water tupelo basal area by county in the Lower Mississippi 

Alluvial Valley, 2010.

Figure 16—Mean per-acre water tupelo basal area by county in the Lower Mississippi 

Alluvial Valley, 2010. 

Basal Area and Species Richness 

The average per-forest-area basal area across 1,344 sampled 

plots in the LMAV was 21.9 square m/ha (95.3 square feet 

per acre; fig. 14). Three hundred plots (22 percent) had total 

basal area values between 60 and 90 square feet per acre. 

Mean county-level basal area ranged from 7.9 to 41.3 m2/

ha (34.6 to 179.9 square feet per acre). On plots where it 

occurred, baldcypress basal area averaged 46.6 square feet 

per acre with a range of 0.5 to 232.0 square feet per acre 

(fig. 15). On plots where water tupelo occurred, the species 

averaged 62 square feet per acre with a range of 1.1 to 317.0 

square feet per acre (fig. 16). There were 107 species (not 

including a general “unknown” category) identified on the 

plots. The number of species (richness) per plot ranged from 

1 to 17 with an average of 6 species per plot. There were 18 

species with only 1 occurrence, and 9 species with only 2 

occurrences.

Standing Dead Trees

There was an average of 13 ± 1 standing dead trees > 5 

inches d.b.h./ha (5 ± 0.4 dead trees per acre) across the 

entire LMAV, although county-level estimates ranged from 

0 trees/ha to 53 ± 34 trees/ha (0–22 ± 14 trees per acre) (fig. 

17). The average number of standing dead trees ≥ 10 inches 

diameter was much lower, at 5 stems/ha (2 stems per acre) 

with a range of 0 to 40 stems/ha (0 to 16 stems per acre). 

Change in Relative Stocking from 1980 to 2010

From 1980 to 2010, loblolly pine experienced the largest 

positive shift in relative stocking, with a mean annual 

increase of 0.13 percent per year. Other species experiencing 

increases in relative stocking include green ash, Nuttall oak 

(Q. nuttallii), water oak, and sugarberry (fig. 18). 
16

Figure 17—Standing dead trees per acre on forests in the Lower Mississippi Alluvial Valley 

by county, 2010.

Standing dead trees 

per acre

<4

4–9

>9

Louisiana

Arkansas

Tennessee

Mississippi

Figure 17—Standing dead trees per acre on forests in the Lower 

Mississippi Alluvial Valley by county, 2010. 

Figure 18—Average annual percent change in relative stocking from 1980 to 2010 by 

species, Lower Mississippi Alluvial Valley. 

Stocking (percent change)

-0.15 -0.10 -0.05 0.00 0.05 0.10 0.15

Species

Water tupelo

Sweetgum

Overcup oak

Willow oak

Baldcypress

Water hickory

Flowering dogwood

Water elm

Eastern hophornbeam

American hornbeam

Boxelder

Southern red oak

Common persimmon

Sugarberry

Slippery elm

American elm

Winged elm

Red maple

Water oak

Green ash

Nuttall oak

Lolblolly pine

Figure 18—Average annual percent change in relative stocking from 1980 to 2010 by species, 

Lower Mississippi Alluvial Valley.
17

Forest-type group

Loblollyshortleaf

Oakpine

Oakhickory

Oak-gumcypress

Elm-ashcottonwood

Exotic

hardwoods

Nonstocked

Biomass (tons per acre)

0

10

20

30

40

50

60

70

Figure 20—Aboveground biomass per acre of live trees (± 95 percent 

confidence interval) by forest-type group, Lower Mississippi Alluvial 

Valley, 2010.

Figure 20—Aboveground biomass per acre of live trees 

(± 95 percent confidence interval) by forest-type group, Lower 

Mississippi Alluvial Valley, 2010. 

Diameter class

Number of trees (million)

0

20

40

60

80

100

120

140

160

180

1980 

2010 

1.0–2.9 3.0–4.9 5.0–6.9 7.0–8.9

9.0–10.9

11.0–12.9 13.0–14.9 15.0–16.9 17.0–18.9 19.0–20.9

21.0–22.923.0–24.925.0–26.9

27.0–28.929.0–30.9 31.0–32.9 33.0–34.9

35.0–36.937.0–38.939.0–40.941+

Figure 19—Number of live sweetgum trees by diameter class, Lower 

Mississippi Alluvial Valley, 1980 and 2010.

Figure 19—Number of live sweetgum trees by diameter class, Lower 

Mississippi Alluvial Valley, 1980 and 2010. 

Water tupelo experienced the largest decline in relative 

stocking, with an average decrease of 0.11 percent per year. 

Simultaneously, declines occurred in the number of water 

tupelo/ha of forest land, from 46 to 27 trees/ha across the 

whole LMAV. 

Although the number of sweetgum trees on forest land 

increased between 1980 and 2010, the relative stocking of 

sweetgum decreased by an average of 0.10 percent per year 

(fig. 18). This discrepancy is attributable to the diameter 

distribution of sweetgum in the LMAV in 2010; the number 

of small-diameter sweetgums nearly doubled between 1980 

and 2010, while trees in the larger diameter classes were far 

fewer (fig. 19). Other species experiencing relative stocking 

declines include baldcypress, willow oak (Q. phellos), 

overcup oak (Q. lyrata), and water hickory (C. aquatic) 

(fig. 18).

Carbon and Biomass 

Aboveground biomass of live trees across the LMAV 

averages 46 tons per acre. Per-acre biomass values are 

highest in the oak-gum-cypress and oak-hickory forest-type 

groups, with 60 tons and 45 tons per acre, respectively (fig. 

20). Total aboveground biomass by species group is shown 

in figure 21. The species group contributing the greatest 

aboveground biomass, 57 million tons per acre, is “other 

eastern soft hardwoods,” which includes boxelder, many of 

the birch species (Betula spp.), sugarberry and hackberry 

(Celtis occidentalis), magnolia species (Magnolia spp.), 

American sycamore, many willow species (Salix spp.), and 
18

several elms (Ulmus spp.). The “other red oaks” and the 

cypress species groups were next largest contributors of 

aboveground biomass, with 50 million and 35 million tons 

per acre, respectively. Above- and belowground carbon in 

live trees was highest in the oak-gum-cypress group, with 

14.6 tons per acre. The volume of standing dead carbon was 

highest in the oak-gum-cypress and elm-ash-cottonwood 

forest-type groups, with 4.7 million and 3.4 million tons per 

acre, respectively. 

CONCLUSIONS

The LMAV is an area rich in natural resources that people 

and wildlife depend on. The BLH forests within the valley 

provide important habitat to migratory bird species and 

a host of mammals, reptiles, amphibians, and fish. Over 

the last century, much of the LMAV forest has been lost 

to agriculture and development, although recent incentive 

programs have encouraged afforestation efforts throughout 

the valley. 

Our report attempts to update the 1986 assessment of 

LMAV forest resources by Rudis and Birdsey and provide 

Figure 21—Aboveground total biomass (± 95 percent confidence interval) 

by species group, Lower Mississippi Alluvial Valley, 2010. 

Figure 21—Aboveground total biomass (± 95 percent confidence interval) by 

species group, Lower Mississippi Alluvial Valley, 2010.

Species group

Aboveground dry weight

(million tons)

0

10

20

30

40

50

60

70

Other eastern soft hardwoods

Other red oaks

Cypress

Sweetgum

Hickory Tupelo and blackgum

Ash Other white oaks Loblolly and shortleaf pine

Select red oaks

Soft maple Select white oaks Eastern noncommercial hardwoods

Other eastern hard hardwoods

Cottonwood and aspen

Beech

Yellow-poplar Other eastern softwoods

Hard maple

Basswood

Black walnut

Other yellow pines

a comprehensive overview of current resources. While 

LMAV forest area has increased overall since the 1980s, the 

area categorized as “BLH” has not increased proportionally 

at the same rate. Instead, upland areas have accounted for 

much of the afforestation, while oak-gum-cypress forests 

have continued to decline. Changes in the LMAV over 

the last two to three decades are due mostly to diversions 

to and reversions from agricultural land, with only a 

small proportion of change due to development. Species 

composition remains similar to composition in the 1980s 

with some notable changes in the abundance of trees that 

typically occupy frequently flooded sites (e.g., water tupelo, 

baldcypress, water hickory) and increases in the number of 

planted loblolly pine trees. 

Advances have been made in the afforestation and 

management of LMAV timber resources since the 1950s, 

with particularly noticeable progress in terms of increasing 

forest area since the 1980s. Concern remains over the future 

of the bottomland resources, however, as demands for flood 

protection continue to increase and hydrologic regimes 

continue to change throughout the valley. Continued 

inventory and monitoring of LMAV resources will aid the 

management of this important resource.
19

Appendix A

Distributions of key species in the Lower Mississippi 

Alluvial Valley according to FIA inventory plots are shown 

in figures A.1–A.16.

Figure A.1—Taxodium distichum. Figure A.2—Acer negundo.
20

Figure A.3—Quercus pagoda. Figure A.4—Triadica sebifera.
21

Figure A.5—Fraxinus pennsylvanica. Figure A.6—Pinus taeda.
22

Figure A.7—Quercus nuttallii. Figure A.8—Quercus lyrata.
23

Figure A.9—Acer rubrum. Figure A.10—Quercus shumardii.
24

Figure A.11—Quercus falcata. Figure A.12—Celtis laevigata.
25

Figure A.13—Liquidambar styraciflua. Figure A.14—Quercus nigra.
26

Figure A.15—Nyssa aquatica. Figure A.16—Ulmus alata.
27

Appendix B

SAMPLING PROCEDURES

Field Methods

For surveys prior to 2005 in the lower Mississippi Alluvial 

Valley (LMAV), field crews visited all sample locations 

in a State and measured attributes at those locations in a 

1- or 2-year period. The Forest Inventory and Analysis 

(FIA) Program of the Forest Service, U.S. Department of 

Agriculture, typically conducted surveys one State at a time. 

This periodic inventory system was designed to provide 

updated forest resource estimates for all States every 7 to 

10 years. The sample design was based on a two-phase 

system, whereby forest area was determined using aerial 

photographs, and stand and tree-level characteristics were 

determined using on-the-ground mensuration techniques.

Timberland area was determined by overlaying a dot grid 

on aerial photographs and interpreting each dot as falling 

on forest or nonforest land. Each dot represented about 

230 acres. Dot counts were adjusted by ground checks at 

permanent sample locations. The ratio of forest to nonforest 

dots provided the percent forest for each county. This 

percentage was then applied to data from the U.S. Bureau 

of the Census statistics to develop an estimate of forest 

area in each parish. Expansion factors based on the number 

of forested plots varied by county or parish, but averaged 

around 6,000 acres per plot.

Stand and tree-level characteristics were measured on plots 

located on a 3- by 3-mile sample grid. At each sample plot 

satellite points were spread over approximately 1 acre, with 

point number one coincident with the corresponding aerial 

photograph plot location. At each forested sample plot, trees 

≥ 5.0 inches diameter at breast height (d.b.h.) were tallied on 

each of the satellite points using a 37.5-factor prism. Trees ≤ 

5.0 inches d.b.h. were tallied on circular 1/275th acre plots.

The FIA inventory today is a three-phase, fixed-plot sample 

survey (Bechtold and Patterson 2005). The three phases of 

the current sampling method are arranged on a hexagonal 

grid design, with each successive phase sampled with less 

intensity. There are 16 phase 2 (P2) hexagons for every 

phase 3 (P3) hexagon, and 27 phase 1 (P1) hexagons for 

every P2 hexagon. P1 hexagons represent about 222 acres, 

while P2 and P3 hexagons represent roughly 6,000 acres and 

96,000 acres, respectively.

Current P1 stratified estimation procedures reduce variance 

associated with estimates of forest land area and produce 

more precise estimates than simple random sampling. A 

statistical estimation technique is used to classify digital 

satellite imagery and initially stratify the land base as 

forest or nonforest to assign a representative acreage to 

each sample plot. Pixels within 60 m (2 pixel widths) of a 

forest/nonforest boundary form two additional strata: forest 

edge and nonforest edge. Forest pixels within 60 m of the 

boundary on the forest side are classified as forest edge 

while pixels within 60 m of the boundary on the nonforest 

side are classified as nonforest edge. The estimated 

population total for the variable is the sum, across all strata, 

of the product of each stratum’s area (from the pixel count) 

and variable’s mean per unit area (from plot measurements) 

for the stratum. 

The P2 sample design utilizes a fixed-radius plot consisting 

of four subplots spaced 120 feet apart in a triangular 

fashion. The cumulative sample area of these four subplots 

is 1/6 of an acre. The cluster plot is a 1.5-acre circle that 

circumscribes the outer boundary of the three outer subplots. 

Trees ≥5.0 inches d.b.h. are measured on each subplot. Trees 

≥1.0 but <5.0 inches d.b.h. and seedlings (<1.0-inch d.b.h.) 

are measured on a microplot (1/300 of an acre; 6.8-foot 

radius) on each of the four subplots. The microplot is offset 

12 feet at 90 degrees from the subplot center. 

A unique feature of this plot design is in the mapping of 

different land use and forest conditions that are encountered 

on the cluster plot. Since the plots are placed on the ground 

without bias, i.e., systematically but at a scale large enough 

to be considered random, there is a probability that the 

cluster plot will straddle more than one type of land use 

or forest condition. When this does occur, a boundary is 

drawn across the plot so that the different homogeneous 

units are identified and isolated. There are two steps in the 

mapping process. The first step involves identifying forest 

and nonforest areas on the plot and establishing a boundary 

line on the plot if both are present. The second step involves 

identifying homogeneous areas in the forested portion of 

the plot based on six factors: (1) forest type, (2) stand size, 

(3) ownership, (4) stand density, (5) regeneration status, and 

(6) reserved status. These, too, are mapped into separate 

entities.

P3 procedures involve sampling on a subset (1/16th) of the 

P2 sample locations. P3 measurements are combined with 

P2 measurements to assess the overall health of forested 

ecosystems within each State. P3 data is not reported here; 

therefore, sampling details are not included.

Determining Forest Resource Statistics

The changes in sample design and plot layout have changed 

the derivation of basic resource statistics, e.g., stocking, 

growth, removals, and mortality. The following section 

briefly describes the methods used and explains how they 

have changed with the transition from the previous to the 

current inventory system.
28

Forest type—Forest type is derived via algorithm using a 

hierarchical (classification tree) decision model. The forest 

type indicates the predominant live-tree species cover. 

Hardwoods and softwoods are first aggregated to determine 

the predominant group, and forest type is selected from 

the predominant group. Eastern softwood groups have ≥50 

percent softwood stocking and contain the named species 

that constitute a plurality of the stocking; the oak-pine group 

and hardwood groups have <50 percent softwood stocking. 

The nonstocked group includes stands <10 percent stocked 

with live trees.

Under the previous sample design, a single forest type was 

determined for the entire plot regardless of the number of 

forest conditions present. The current fixed-radius inventory 

design identifies a forest type for each forest condition. 

Estimating volume—Currently, FIA computes tree volume 

using a simple linear regression model (D2H) that predicts 

gross cubic foot volume from a 1-foot stump to a 4-inch 

upper diameter for each sample tree based on d.b.h. (D) 

and total height (H). Separate equation coefficients for 77 

species or species groupings are used; these are developed 

from standing and felled tree volume studies conducted 

across several Southern States (Oswalt and Conner 2011). 

Volume in forks or limbs outside of the main bole is 

excluded. FIA derives net cubic foot volume by subtracting 

a field crew estimate of rotten or missing wood for each 

sample tree. Volume of the saw-log portion (expressed 

in International 1/4-inch board feet and in cubic feet) of 

sample trees is computed using board foot–cubic foot ratio 

equations. Equations and coefficients were derived from 

standing and felled-tree volume studies conducted across 

several Southern States. 

Methods used to estimate tree volumes in the previous 

inventory differed from those described above. FIA derived 

tree volume from several measurements on each tree tallied 

on forested sample plots. These measurements included 

d.b.h., bark thickness, total height, bole length, log length, 

and up to four upper-stem diameters that defined pole top, 

pole mid, saw top, and saw mid. Gross tree volumes (cubic 

and board foot values) were determined by applying the 

formula for a conic frustum to sections of the bole. The 

volumes of the sections were then added together to produce 

a total stem volume. Obtaining net cubic foot volume 

involved subtracting a field crew estimate of rotten or 

missing wood for each sample tree. Merchantable volume 

was calculated from measurements of the bole from a 

1-foot stump to an upper-stem stopping point determined 

by merchantability standards. The upper-stem diameter 

at this point could be as low as 4 inches but often was 

larger depending upon the perceived condition and product 

merchantability of the upper tree bole.

Although both current and previous plot designs are 

statistically valid, the naturally occurring noise in the data 

hinders rigorous trend assessments over time. When a 

design changes or plots are not remeasured, the true impact 

of such a change on trend analysis is unknown. The only 

way to quantify this impact with certainty would be to 

make measurements using both plot designs simultaneously 

and compare the results of these two independent surveys. 

Resources were not available to do this.
29

Bechtold, W.A.; Patterson, P.L., eds. 2005. The enhanced forest 

inventory and analysis program—national sampling design and 

estimation procedures. Gen. Tech. Rep. SRS–80. Asheville, 

NC: U.S. Department of Agriculture Forest Service, Southern 

Research Station. 85 p.

Faulkner, S.P.; Bhattarai, P.; Allen, Y. [and others]. 2009. 

Identifying baldcypress-water tupelo regeneration classes in 

forested wetlands of the Atchafalaya Basin, Louisiana. Wetlands. 

29(3): 809–817.

Fredrickson, L.H. 2005. Contemporary bottomland hardwood 

systems: structure, function and hydrologic condition 

resulting from two centuries of anthropogenic activities. In: 

Fredrickson, L.H.; King, S.L.; Kaminski, R.M., eds. Ecology 

and management of bottomland hardwood ecosystems: the state 

of our understanding. Gaylord Memorial Laboratory Special 

Publication No. 10. Puxico, MO: University of MissouriColumbia: 19–35. 

Gardiner, E.S.; Oliver, J.M. 2005. Restoration of bottomland 

hardwood forests in the Lower Mississippi Alluvial Valley, 

U.S.A. In: Stanturf, J.A.; Madsen, P., eds. Restoration of boreal 

and temperate forests. Restoration of bottomland hardwood 

forests in the Lower Mississippi Alluvial Valley, U.S.A. Boca 

Raton, FL: CRC Press: 235–251.

Interagency Floodplain Management Review Committee. 1994. 

A blueprint for change—sharing the challenge: floodplain 

management into the 21st century. Final report. 272 p. http://

www.floods.org/PDF/Sharing_the_Challenge.pdf. [Date 

accessed: October 2012]. 

Jenkins, W.A.; Murray, B.C.; Kramer, R.A.; Faulkner, S.P. 2010. 

Valuing ecosystem services from wetlands restoration in the 

Mississippi Alluvial Valley. Ecological Economics. 69: 1051–

1061.

King, S.L.; Shepard, J.P.; Ouchley, K.; Neal, J.A. 2005. 

Bottomland hardwood forests: past, present, and future. In: 

Fredrickson, L.H.; King, S.L.; Kaminski, R.M., eds. Ecology 

and management of bottomland hardwood systems: the state 

of our understanding. Gaylord Memorial Laboratory Special 

Publication No. 10. Puxico, MO: University of MissouriColumbia: 1–17.

King, S.L.; Twedt, D.J.; Wilson, R.R. 2006. The role of the wetland 

reserve program in conservation efforts in the Mississippi River 

Alluvial Valley. Wildlife Society Bulletin. 34(4): 914-920.

Lower Mississippi Valley Joint Venture Office Forest Resource 

Conservation Working Group. 2007. Restoration, management, 

and monitoring of forest resources in the Mississippi alluvial 

valley: recommendations for enhancing wildlife habitat. 

Wilson, R.; Ribbeck, K.; King, S.; Twedt. D., eds. Final 

report. Vicksburg, MS: Lower Mississippi Valley Joint 

Venture Office. 137 p. http://www.mdwfp.com/media/8855/

mavdesiredforestconditionsfinalreport.pdf. [Date accessed: 

October 2012].

Literature Cited

Miles, P.D. 2012. Forest inventory EVALIDator web-application 

version 1.5.00. St. Paul, MN: U.S. Department of Agriculture 

Forest Service, Northern Research Station. http://www.fia.fs.fed.

us/tools-data/default.asp. [Date accessed: June 4 to July 24, 

2012].

Oswalt, C.M.; Conner, R.C. 2011. Southern forest inventory 

and analysis volume equation user’s guide. Gen. Tech. Rep. 

SRS–138. Asheville, NC: U.S. Department of Agriculture Forest 

Service, Southern Research Station. 22 p. 

Oswalt, C.M.; Stringer, J.A.; Turner, J.A. 2008. Shifts in relative 

stocking of common tree species in Kentucky from 1975 to 

2004. In: Jacobs, D.F.; Michler, C.H., eds. 2008. Proceedings, 

16th central hardwood forest conference. Gen. Tech. Rep. 

NRS–P–24. Newtown Square, PA: U.S. Department of 

Agriculture Forest Service, Northern Research Station: 194–203.

Rosson, J.F., Jr. 2001. Forest resources of Mississippi, 1994. 

Resour. Bull. SRS–61. Asheville, NC: U.S. Department of 

Agriculture Forest Service, Southern Research Station. 78 p.

Rosson, J.F., Jr. 2002. Forest resources of Arkansas, 1995. Resour. 

Bull. SRS–78. Asheville, NC: U.S. Department of Agriculture 

Forest Service, Southern Research Station. 82 p.

Rosson, J.F., Jr.; McWilliams, W.H.; Frey, P.D. 1988. Forest 

resources of Louisiana. Resour. Bull. SO–130. New Orleans: 

U.S. Department of Agriculture Forest Service, Southern Forest 

Experiment Station. 81 p.

Rudis, V.A.; Birdsey, R.A. 1986. Forest resource trends and current 

conditions in the lower Mississippi valley. Resour. Bull. SO–116. 

New Orleans: U.S. Department of Agriculture Forest Service, 

Southern Forest Experiment Station. 7 p. 

Schoenholtz, S.H.; James, J.P.; Kaminski, R.M. [and others]. 2001. 

Afforestation of bottomland hardwoods in the lower Mississippi 

alluvial valley: status and trends. Wetlands. 21(4): 602–613.

U.S. Department of Agriculture Natural Resources Conservation 

Service. 2012. 2011 WRP cumulative agreement enrollments. 

http://www.nrcs.usda.gov. [Date accessed: July 17, 2012].

U.S. Soybean Export Council. 2006. U.S. Soy: International 

buyer’s guide. http://www.ussec.org/resources/buyers-guide/. 

[Date accessed: August 29, 2012].



Oswalt, Sonja N. 2013. Forest Resources of the Lower Mississippi 

Alluvial Valley. Gen. Tech. Rep. SRS-177. Asheville, NC: U.S. 

Department of Agriculture Forest Service, Southern Research 

Station. 29 p. 

At one time, the Lower Mississippi Alluvial Valley was covered 

by almost 25 million acres of forest. By the mid-1980s, all that 

remained of the valley’s forested land was roughly 6.6 million acres. 

This report addresses a gap in data about this land by providing, for 

the first time since 1986, comprehensive new estimates of forest 

area, volume, carbon, and tree species stocking change. 

Keywords: Bottomland hardwoods, Forest Inventory and Analysis, 

Lower Mississippi Alluvial Valley, stocking.

Scan this code to submit your feedback,

or go to www.srs.fs.usda.gov/pubeval

You may request additional copies of this publication by e-mail at pubrequest@fs.fed.us.

Please, limit requests to two copies per individual. 
The Forest Service, United States 

Department of Agriculture (USDA), is 

dedicated to the principle of multiple use 

management of the Nation’s forest resources 

for sustained yields of wood, water, forage, 

wildlife, and recreation. Through forestry 

research, cooperation with the States and private forest 

owners, and management of the National Forests and 

National Grasslands, it strives—as directed by Congress—

to provide increasingly greater service to a growing Nation.

The USDA prohibits discrimination in all its programs and 

activities on the basis of race, color, national origin, age, 

disability, and where applicable, sex, marital status, familial 

status, parental status, religion, sexual orientation, genetic 

information, political beliefs, reprisal, or because all or 

part of an individual’s income is derived from any public 

assistance program. (Not all prohibited bases apply to all 

programs.) Persons with disabilities who require alternative 

means for communication of program information (Braille, 

large print, audiotape, etc.) should contact USDA’s 

TARGET Center at (202) 720-2600 (voice and TDD).

To file a complaint of discrimination, write to USDA, 

Director, Office of Civil Rights, 1400 Independence Avenue, 

SW, Washington, D.C. 20250-9410, or call (800) 795-

3272 (voice) or (202) 720-6382 (TDD). USDA is an equal 

opportunity provider and employer.