Eastern United States
Deciduous Forests
Presented by:
John Girard
Table of Contents
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Definition
Distribution
Physiognomy
Functions
Ecosystem threats
Conclusion
Questions?
Definition
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de·cid·u·ous adj.
Temporary or tending to
fall off
Deciduous forests exist in
areas of mild temperatures
(-30˚C to 30˚C) and where
the mean annual rainfall is
between 75 – 150 cm
Global Distribution
Deciduous Forests are found in:
 Eastern North America
 Europe
 Southeastern Russia
 China
 Japan
Eastern United States Deciduous
Forest Distribution
Temperature decreases in
higher lattitudes
Climate becomes drier in
midwestern states
Deciduous Forest Physiognomy
(Association = Climax Units)
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Mixed Mesophytic
Western Mesophytic
Oak - Hickory
Oak - Chestnut
Oak – Pine
Southeastern Evergreen
Beech – Maple
Maple – Basswood
Hemlock – White Pine – Northern Hardwood
Forest Distribution
Boreal/ Spruce-Fir
Grassland
Oak-Hickory
Hemlock-White PineNorthern Hardwoods
Maple-Basswood
Beech-Maple
Western Mesophytic
Mixed Mesophytic
Oak-Chestnut
Oak-Pine
Southeastern Evergreen
Subtropical
Why are the associations
different?
Differences in vegetation
result from:
 Topography
 Elevation
 Temperature
 Moisture
 Light
 Soil type
Slope Orientation Changes
Microclimate
Northern slopes have:
 Lower air and soil
temperatures
 A smaller vapor
pressure deficit, which
is a measure of water
availability and
evaporation
 Less ambient light
Soil Types
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Xeric = Dry
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Mesic = moderately
moist
Humus
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Deciduous forests
contain rich soils with a
layer of humus
Humus forms from the
decay of forest litter
Detritus prevents
sudden changes in
temperature protecting
root structures
Mixed Mesophytic Association
Mesophytic : being adapted to a
moderately moist environment
Soil: Mesic and well drained
Dominant Species:
 Beech
 Tulip poplar
 Basswood
 Sugar maple
 Sweet buckeye
 Chestnut*
 Red oak
 White oak
 Hemlock
Western Mesophytic Association
Soil: Mesic
Dominant Species:
 Oak
 Hickory
 Tulip poplar
 Beech
 Chestnut*
Oak – Hickory Association
Soil: Xeric
Dominant Species:
 Oak
 Hickory
Oak – Chestnut Association
Soil: Mesic to xeric
Dominant Species:
 White oak
 Chestnut*
 Red oak
 Chestnut oak
 Tulip poplar
Oak – Pine Association
Soil: Xeric red and yellow
clays
Dominant Species:
 White oak
 Hickory
 Loblolly pine
 Yellow pine
Southeastern Evergreen Association
Soil Type: Xeric red clay
which is poorly aerated
and nutrient deficient
Dominant species:
Northern Region:
 White oak
 Hickory
Southern Region:
 Loblolly pine
 Yellow pine
Beech – Maple Association
Soil: Mesic and well drained
Dominant Species:
 Beech
 Sugar Maple
Maple – Basswood Association
Soil: Mesic and well drained
Dominant Species:
 Sugar Maple
 Basswood
 Red oak
Hemlock – White Pine – Northern
Hardwood Association
Soil: Mesic to xeric
Dominant Species:
 Sugar maple
 Beech
 Basswood
 Yellow birch
 Hemlock
 White pine
 Red pine
 Red spruce
Layers of the Deciduous Forest
Canopy (5+ m)
Understory (0-5m)
Functions
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Carbon storage (Influx of CO2)
Mineral storage (K, Ca, Mg, P, N)
Photosythesizers (Producers)
Soil formation
Prevent soil erosion
Provide habitat for fauna
Provide carbohydrates for fauna
Coarse Woody Debris Dynamics
in Two Old-Growth Ecosystems
Mark E. Harmon and Chen Hua
Bioscience Vol. 41(9) October 1991
Coarse woody debris:
 Potentially stores large
amounts of carbon in forest
ecosystems
 Reduce soil erosion
 Store nutrients and water
 Serve as seedbeds
 Provide habitats for
decomposers and fauna
Coarse Woody Debris Dynamics
in Two Old-Growth Ecosystems
Mark E. Harmon and Chen Hua
Comparison of an old growth deciduous forest in China
and an old growth coniferous forest in Oregon
Compared:
 Amount of coarse woody debris
 Decay rates
 Tree mortality
Coarse Woody Debris Dynamics
in Two Old-Growth Ecosystems
Mark E. Harmon and Chen Hua
Findings:
 More coarse woody debris was
found in the coniferous forest
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Decay rates were inversely
proposional to amount of
precipitation
Low precipitation  High decay
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Deciduous trees have a higher
mortality rate (1.22/yr vs 0.7/yr)
Snags
Snags provide habitat for
forest fauna
Nutrient Translocation in
the Outer Canopy and
Understory of an Eastern
Deciduous Forest
R.J. Luxmoore
T. Grizzard
R.H. Strand
Forest Science Vol. 27 (3) 1981 pg 505-518
Methods
Data from earlier studies conducted on the foliar
nutrient status of 10 eastern forest species and on
throughfall leaching of four major communities of the
eastern deciduous forest were used to calculate foliar
nutrient translocation rates including adjustment for
leaching losses.
Tree foliage was collected with a shotgun from outer tree
canopies and analyzed along with understory foliage and
evergreens for nutrient concentrations
Chemical analysis after throughfall water was compared
to seasonal mean nutrient concentrations
Results
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K and Ca had the highest leaching rate
Leaching is greater in autumn due to weathered and
cracked leaf cuticles
Very high nutrient translocation rate for canopy
deciduous species following bud burst and a late
season flux back to the tree
During leaf senescence a significant return of
nutrients from leaf to twig
Results Cont.
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Phosphorus was translocated back to the trunk
by the end of May; nitrogen was translocated
back to the trunk by mid June
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Nitrogen uptake from soil could account for
only 25% of foliar nitrogen influx; nitrogen
must be stored somehow inside the tree
Threats to Forest Ecosytem
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Invasive species of flora
and fauna
Fire
Logging (Forest
management)
Human Developments
Windfall
Herbivory
Invasive Species
Compete for forest
resources
 Water
 Light
 Space
 Nutrients
Invasive Species List
Pathogens
Cryphonectria parasitica (Chestnut Blight)
Phytophthora ramorum (Sudden Oak Death)
Ophiostoma ulmi (Dutch Elm Disease)
Mycoplasma like organism (Ash Yellows)
Vines
Celastrus orbiculatus (Oriental bittersweet)
Pueraria montana (Kudzu)
Lonicera japonica (Japanese honeysuckle)
Polygonum perfoliatum (Mile a minute weed)
Trees or shrubs
Ailanthus altissima (Tree of heaven)
Berberis thunbergii (Japanese barberry)
Chestnut Blight
Before the introduction of chestnut
blight in 1904American chestnut
Constituted 70% of the eastern
deciduous forest basal area
Within 40 years american chestnut
represented less than 1% of the forest
basal area
Pathogens, Patterns, and
Processes in Forest
Ecosystems
Pathogens influence and are influenced by
forest development and landscape
characteristics
Bioscience Vol. 45 (1) Jan. 1995
John D. Castello
Donald J. Leopold
Peter J. Smallidge
Findings
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Pathogens select less vigorous or genetically unfit
individuals to incite disease causing tree mortality
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Tree mortality can be large scale leading to secondary
succession or small scale causing canopy gaps
leading to secondary succession
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Oak – Hickory forests have succeeded oak – chestnut
Findings Cont.
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Beech bark disease in New York lead to an increase
of hemlock
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Oak wilt in Wisconsin lead to a loss of red and black
oak, which were replaced by sugar maple
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Dutch elm disease resulted in a increase in shade
tolerant species and an Illinois forest witnessed a 60%
increase of sugar maple
Findings Con’t.
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Pathogens affect forest fauna as the chestnut blight
lowered mast (Nuts used as food) production, thereby
lowering the diversity of fauna
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Forest management practices influence the effects of
pathogens on forest structure e.g. fire supression
prevents pathogen destruction, roads altering drainage
patterns resulting in succession, etc…
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Disease is essential to ecological balance in the
forest; pathogens increase tree mortality which
facilitates succession
Fire and the
Development of Oak
Forests
In eastern North America, oak distribution
reflects a variety of ecological paths and
disturbance conditions
Bioscience Vol. 42 (5) May 1992
Marc D. Abrams
Findings
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Paleoecology of eastern oak forests show a change
from pine to oak domination coinciding with an
increase in charcoal abundance
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Fire favors oak species due to their thick bark,
sprouting ability, resistance to rotting after scarring
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Periodic fire keeps succession in check as later
successional species have low resistance to fire
Findings Con’t.
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Periodic fires resulted from lightning strikes and Indian
activities e.g. cooking, heat, combating insects, killing
woody vegetation, etc…
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Logging of White pine resulted in an increase of red oak
from the understory
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Oak forests are being successionally replaced as oak
seedlings are shade intollerant and are dominated by
maple and black cherry seedlings
Logging
Changes:
 Landscape structure
 Drainage patterns
 Forest species diversity
 Temperature and transpiration
 Compaction and erosion of soil
 Size of canopy gaps
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Trampling of understory species
Allows for invasive species to
succeed
Loss of habitats for fauna
Slash
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Prevents soil erosion to
minimize damage to
surrounding flora
Human Developments
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New construction
destroys forest
Loss of flora and fauna
Windfall
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Occurs during storms
Allows for secondary
succession and forest
species variablility
Herbivory
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Can result in disease or
death of tree
Conclusion
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Deciduous forests have varying physiognomy due to
differences in climate, elevation, topography, and soil
type
Storage of minerals, production of carbohydrates
through photosynthesis, prevention of soil erosion,
and faunal habitats are all functions of Deciduous
forests
Threats to the forest ecosystem include; invasive
species, fire, logging, human developments, windfall,
and herbivory
Questions?
References Cited
Abrams, Marc D. ; Fire and the Development of Oak Forests;
Bioscience Vol. 42 (5) May 1992; 346-353
Barbour, Michael B. , and Billings, William Dwight; North
American Terrestrial Vegetation; Cambridge University Press,
United Kingdom; 2000. 357-395
Braun, E. Lucy; Deciduous Forests of Eastern North America;
Hafner Publishing Company, New York; 1967. 3-38
References Cited Cont.
Castello, John D., Leopold, Donald J., and Smallidge, Peter
J.; Pathogens, Patterns, and Processes in Forest Ecosystems;
Bioscience Vol 45 (1) January 1995; 16-24
Harmon, Mark E.; Coarse Woody Debris Dynamics in Two
Old-Growth Ecosystems; Bioscience Vol 41 (9) October
1991; 604-610
Luxmoore, R.J., Grizzard, T., and Strand, R.H.; Nutrient
Translocation in the Outer Canopy of an Eastern Deciduous
Forest; Forest Science Vol 27 (3) 1981; 505-518
References Cited Cont.
Steinman, Jim; Changes in Composition of the Mixed Mesophytic
Forest: Effects of Succession and Disturbance;
http://www.srs.fs.usda.gov/pubs/1381 ; 1999