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Eastern United States Deciduous Forests. Presented by: John Girard. Table of Contents. Definition Distribution Physiognomy Functions Ecosystem threats Conclusion Questions?. Definition. de·cid·u·ous adj. Temporary or tending to fall off
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Eastern United States Deciduous Forests Presented by: John Girard
Table of Contents • Definition • Distribution • Physiognomy • Functions • Ecosystem threats • Conclusion • Questions?
Definition • de·cid·u·ousadj. • 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) • Mixed Mesophytic • Western Mesophytic • Oak - Hickory • Oak - Chestnut • Oak – Pine • Southeastern Evergreen • Beech – Maple • Maple – Basswood • Hemlock – White Pine – Northern Hardwood
Boreal/ Spruce-Fir Grassland Oak-Hickory Hemlock-White Pine-Northern Hardwoods Maple-Basswood Beech-Maple Western Mesophytic Mixed Mesophytic Oak-Chestnut Oak-Pine Southeastern Evergreen Subtropical Forest Distribution
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 • Xeric = Dry • Mesic = moderately moist
Humus • 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 AssociationMesophytic : being adapted to amoderately 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 • 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 EcosystemsMark E. Harmon and Chen HuaBioscience 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 EcosystemsMark 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 EcosystemsMark E. Harmon and Chen Hua Findings: • More coarse woody debris was found in the coniferous forest • Decay rates were inversely proposional to amount of precipitation Low precipitation High decay • 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 • 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. • Phosphorus was translocated back to the trunk by the end of May; nitrogen was translocated back to the trunk by mid June • 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 • 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 EcosystemsPathogens influence and are influenced by forest development and landscape characteristicsBioscience Vol. 45 (1) Jan. 1995 John D. Castello Donald J. Leopold Peter J. Smallidge
Findings • Pathogens select less vigorous or genetically unfit individuals to incite disease causing tree mortality • Tree mortality can be large scale leading to secondary succession or small scale causing canopy gaps leading to secondary succession • Oak – Hickory forests have succeeded oak – chestnut
Findings Cont. • Beech bark disease in New York lead to an increase of hemlock • Oak wilt in Wisconsin lead to a loss of red and black oak, which were replaced by sugar maple • 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. • Pathogens affect forest fauna as the chestnut blight lowered mast (Nuts used as food) production, thereby lowering the diversity of fauna • 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… • Disease is essential to ecological balance in the forest; pathogens increase tree mortality which facilitates succession
Fire and the Development of Oak ForestsIn eastern North America, oak distribution reflects a variety of ecological paths and disturbance conditionsBioscience Vol. 42 (5) May 1992 Marc D. Abrams
Findings • Paleoecology of eastern oak forests show a change from pine to oak domination coinciding with an increase in charcoal abundance • Fire favors oak species due to their thick bark, sprouting ability, resistance to rotting after scarring • Periodic fire keeps succession in check as later successional species have low resistance to fire
Findings Con’t. • Periodic fires resulted from lightning strikes and Indian activities e.g. cooking, heat, combating insects, killing woody vegetation, etc… • Logging of White pine resulted in an increase of red oak from the understory • 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 • Trampling of understory species • Allows for invasive species to succeed • Loss of habitats for fauna
Slash • Prevents soil erosion to minimize damage to surrounding flora
Human Developments • New construction destroys forest • Loss of flora and fauna
Windfall • Occurs during storms • Allows for secondary succession and forest species variablility
Herbivory • Can result in disease or death of tree
Conclusion • 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
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