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The Natural State of the Forest
By: Andrea Muffuletto
The Natural State of the Forest
Arkansas is home to 18.8 billion acres of forest, including the Ozark, the Ouachita, and
the St. Francis National Forests. Woodlands account for over 56% of Arkansas’ total land base
and are vital to the state’s economy, national image, and most importantly the ecosystem (Gary,
2006). Because of the integral role of the forest here in Arkansas, it is critical to recognize one of
the most pressing issues regarding its condition- the issue of overcrowding. Overcrowding refers
to the overabundance of vegetation in an ecosystem, which leads to increased competition for
resources such as light, water, and nutrients. This problem is the result of the elimination of
natural fire regimes. It has compromised the natural integrity of the woods by promoting the
growth of non-native species and has led to increased susceptibility of vegetation to drought,
disease, and pests. Few solutions have been posed to address the issue of forest overcrowding,
most of which are widely controversial, such as prescribed burning and sustainable timber
management.
Population Ecology and the Historic Role of Fire
Overcrowding is a concept often associated with population ecology, which is the study
of how species interact with their environment. The overcrowding of Arkansas’ forest directly
correlates with the spread and additional growth of non-native species, which have resulted from
accidental introduction and prior management techniques. Effects associated with this include
wildlife habitat degradation, displacement of native species, altered soil, and hydrological
conditions, as well as decreased biodiversity. In relation to overcrowding, population ecologists
state “a population can decline because it lacks resources or it can decline because it is prey to
another species that is increasing in numbers” (Colyvan 2008). Both of these explanations
appropriately model the current conditions found in Arkansas forests. The native hardwood
population is slowly diminishing as a result of increased competition for resources, specifically
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The Natural State of the Forest
competition with shade tolerant trees such as maple, ash, and gum trees. Further evidence
suggests that with the elimination of natural fire practices, non-native species have been able to
thrive and out-compete the already stressed hardwood populations.
Fire has played a fundamental role in the history of forest ecology and is useful in
identifying the origins of forest overcrowding. Prior to human inhabitation, lightning ignited
wildfires progressed unimpeded across the landscapes, limited only by physical factors such as
topography, bodies of water, and weather patterns. Dendrochronological studies have indicated
that most forests were exposed to fire on a time interval of every five to ten years. Exposure to
recurrent wildfires led to the adaption of native species, forming a fragile ecosystem dependent
on frequent burnings. When Native Americans inhabited the land it was a common practice to
utilize fire to maintain ecosystems. This can be seen by the increased rate of charcoal deposits in
dendrochronological studies, which essentially are marks in the rings of trees illustrating at what
points in time the tree was exposed to fire. Historical records documenting early European
migration to the Ozark Mountains cite firsthand accounts of these Indian practices. Within the
next few centuries, consistent European settlement in the area led to modified practices in
regards to natural fire, focusing primarily on fire suppression as a means to control what was
viewed as a destructive force. Unfortunately, this mindset has carried into the twentieth-century
and it has only been within the past 75 years that ecologists have recognized “that fire was a
primary agent of change in many ecosystems” (National Park Service n.d), and by suppressing
these natural phenomena settlers unintentionally altered the natural state of the Arkansas
woodlands.
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The Natural State of the Forest
Appearances may be Deceiving
Oak-hickory forests have been the dominant ecosystem present in the Ozarks for over
4,000 years. Upon initial observation, Arkansas forests may appear to be healthy and highly
productive, but in reality they are an unhealthy ecosystem dominated by non-native species that
are able to thrive in the densely populated environment. The forests we see today starkly
contrasts accounts recorded from the 1800s by men such as Henry Rowe Schoolcraft. Known to
have traveled widely throughout the Ozark Mountains, he is quoted as saying they were “covered
chiefly by oaks without underbrush. A tall thick, and rank growth of wild grass covers the whole
country, in which the oaks are standing interspersed, like fruit trees in some well-cultivated
orchard” (Purcell, 2004). The picturesque appearance described by Schoolcraft can no longer be
found in the Arkansas woodlands due to an increase in shade-tolerant vegetation. This results in
the inhibition of small oak tree regeneration, which has led to the overabundance of other tree
species and the emergence of closed canopy stands. The understory of the forest is dominated by
shrubs, poison ivy, and Virginia creeper, which in conjunction with a high stem density of 300 to
1000 stems per acre (as opposed to 38-76 stems per acre recorded in the 1800s), excludes the
growth of native warm season grasses and wildflowers that once flourished on the forest floor
(Ozark St. Francias National Forest, n.d). This decrease in forest floor growth negatively
impacts animal species that utilize the vegetation for habitat or as a food source. Native species
such as white-tailed deer, rabbits, quail, and turkey all benefit from an open understory, which
allows them to easily find food and shelter. In addition, studies have shown that migratory birds
benefit from an open understory because it is better suited for the foraging of seeds and provides
optimal conditions for nesting.
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The Natural State of the Forest
Susceptibility
The oak and hickory trees native to Arkansas are considered highly susceptible to
drought, disease, and pests as a result of the already stressed ecosystem. Historically,
competition for essential resources such as light, water, and nutrients was uncommon, but with
the increasing diversity of the understory and the added pressure of competition, these native
species have become extremely vulnerable to insects such as the Red Oak Borer and diseases
such as Hypoxylon canker.
The red oak borer is a small insect whose larvae bore tunnels into live oak trees,
damaging the trees and providing access for other dangerous pests such as carpenter worms,
timber worms, and carpenter ants. Because of the densely populated forests and overabundance
of understory, these borers are able to reproduce and migrate rapidly, severely damaging large
quantities of native oak trees and thus promoting additional growth of shade-tolerant vegetation.
The insect is particularly destructive due to the fact that the forest is already in a weakened state,
and has recently caused large scale devastation in the Boston Mountain Range. In 1999,
following a two year drought, 1.6 million acres of red oak were infested by the borer in
Northwest Arkansas, killing 30-40% of the red oak trees. In the event of a wildfire, these
standing dead trees act as a chimney and draw flames to the level of the tree tops, resulting in
high vegetative mortality rates (Starkey 2004).
Hypoxlon canker is a fungal infection which attacks weakened red and black oak trees.
Its ability to colonize is contingent upon the health of the tree. The opportunistic fungi are unable
to infect healthy trees, but will rapidly kill damaged ones by entering the tree and causing decay.
Similar to the red oak borer, overcrowded conditions are favorable for the spread of this fungus.
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The Natural State of the Forest
New infections can be caused by aerial migration from one tree to another, promoting additional
decay as the fungus moves through the forest.
In addition to these problems, overcrowding in the forest can result in devastating
droughts. The densely populated ecosystem requires a greater amount of water than previously
needed in order to sustain the growth of the nearly 300-1000 stems per acre. The increased
demand for water has become one of the primary factors influencing competition.
Prescribed Burning and Sustainable Timber Harvesting
Overcrowding in the Arkansas woodlands is due to the elimination of natural fire regimes
in the twentieth-century. Long viewed as a destructive force, fire is now considered by many
ecologists to be a natural remedy for this issue. Employed by many state and government
agencies, prescribed burning utilizes low-intensity fires in an attempt to restore the forest to its
natural state. Because many of the shade tolerant species have only been present for the last two
hundred years, and have never been exposed to fire, they are easily killed by exposure to the
flames of a prescribed burn. In addition to restoring the native forest, this solution also reduces
hazardous fuels which can lead to destructive wildfires. This particular method of conservation
is considered controversial by many because of the perceived dangers surrounding the use of fire
and the high costs associated with it. This results in many individuals viewing prescribed burning
as being an ineffective and an unnecessary solution to the problem.
A second solution to this problem is mechanical thinning through the use of sustainable
timber harvesting. Small, family-owned sawmill operations have been sustainably logging in the
Ozark Mountains for hundreds of years. Sustainable logging involves the removal of a portion of
the timber in a forest stand, leaving enough for re-growth. Two of the major benefits of this
method are eliminating wastefulness and the methods ability to affect the diversity of tree
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The Natural State of the Forest
species. Unfortunately, a stigma associated with this solution is that it is often thought to be
synonymous with the large-scale, clear-cutting practices of major timber companies. Practices of
logging companies are not the solution to the problem of overcrowding, as they often clear cut
old growth hardwoods and replant pine. This process is even more detrimental to the native
ecosystem than the overpopulation problems. It is imperative that a distinction is made between
the timber management practices utilized by small sustainable sawmills and the large timber
harvesting companies.
“Before our eyes, many areas of the Ozarks are shifting from majestic oak woodlands to
overstocked stands of maples, ashes, and other tree species” (Purcell 2004). With the extinction
of fire practices that were once used to control undergrowth in the forest, issues of overcrowding
have threatened the expected lifespan of the oak-hickory forests. Competition for resources has
led to a dramatically weakened oak-hickory population in the state of Arkansas, making these
native trees more susceptible to disease and pests. Sustainable timber harvesting as well as
prescribed burning are two of the primary means of combatting forest overcrowding, but
controversy surrounds both of these practices. This environmental issue is pressing because the
oak-hickory forests present in Arkansas are among the very few in the entire world. Because
these forests cover such a large portion of Arkansas they are crucial to the historic meaning of
the natural state. The Arkansas Heritage Commission is quoted in saying “oak-hickory forests
are fairly common, but high quality examples of them have become so rare that each deserves
special attention. Thus the opportunity to preserve the best example of a type can be as important
as a chance to preserve the only example.”
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The Natural State of the Forest
References
Arkansas Natural Heritage Commision. (2011). Endangered, Threatened, and Rare Species.
Little Rock.
Colyvan, M. (2008). Chapter 17. Population Ecology. In A Companion to the Philosophy of
Biology.
Gray, J. (2006). Forestry. University of Arkansas Division of Agriculture .
Lamar, J. (2001, April 13). Forester says disease killing Arkansas oak trees. Delta Farm Press ,
p. 1.
Laurel, J, Haavik, L, & Joshua, M. J. (2011). Oak decline and red oak borer outbreak: impact in
upland oak-hickory forests of Arkansas, USA. Institute of Chartered Forests.
Ozark St. Francias National Forest. Ozark Highlands Ecosystem Restoration Proposal.
Russellville: USDA.
Purcell, L. (2004, March). Resotring the Health of our Forests. Hector, Arkansas.
Starkey, D, Oliveria, F, Mangini, A, & Mielke, M. (2004). Oak Decline and Red Oak Borer in
the Interior Highlands of Arkansas an Missouri: Natural Phenomena, Severe
Occurrences. Gen. Tech. Rep.
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