1. 1.to understand dendrology. 2.to evaluate tree anatomy. 3.to determine the age of a tree. 4.to...
TRANSCRIPT
The Study of Trees
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Dendrology:
Objectives1. To understand dendrology.
2. To evaluate tree anatomy.
3. To determine the age of a tree.
4. To identify tree species.
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Dendrology • Is the study of plants whose support
system is composed mainly of woody material
• Studies plants including the following:– trees– shrubs– vines
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Trees • Are woody plants with one central trunk• Have a protective covering called bark• Have branches reaching in all directions
from the trunk
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Shrubs• Are plants with
numerous woody stems
• Are usually lower in height than trees
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Vines • Are woody plants which require a
structure for support• Have very flexible stems• Are mostly flowering plants
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Tree Anatomy
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Tree Anatomy • Includes the following major
parts:–leaves–trunk–branches–roots
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Leaves • Are normally green• Are flattened, lateral structures
attached to a stem • Function as the primary organ of
photosynthesis and transpiration in most plants
• Take in oxygen through openings called stomata
• Are protected from dehydration through the external waxy layer
• Adapt to the environment with hairs, bristles, scales or other modifications
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Trunk & Branches • Include a protective layer called
the bark• Include the following functions:
– support– protection from injury and
decay– transportation of liquids– storage of starch and other
minerals10
Bark • Consists of the following two
zones:–inner bark–outer bark
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Inner Bark • Is also known as phloem• Contains tubular cells which distribute
sugars and growth regulators from the leaves and buds to other parts of the tree
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Outer Bark • Consists of layers of inner bark which have
died and been pushed out by the growth of the tree
• Is the tree’s first line of defense to disease caused by insects and bacteria or damage by humans, heat and cold
• Contains a meristematic region
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Meristematic Regions • Are the areas where new cells are formed
which allow the tree to grow• Are located in the following places:
– root tips– buds at the end of twigs– the area between the bark and wood
known as the vascular cambium zone• strongest defense against decay• covers up minor wounds• blocks off and rids entire columns of
rot-infected wood
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Trunk & Branches • Contain the xylem
– which is also known as wood– includes the following types of cells:
• tubular connective cells• ray cells• parenchyma cells
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Tubular Connective Cells
• Run parallel to the trunk or branch
• Carry water and minerals up from the roots
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Ray Cells • Distribute food to living cells• Are sheets of cells in the wood• Are tubes which run from the
inner bark to the center of the tree
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Parenchyma Cells
• Store starch crystals which have the following functions:– are the main raw material for
the fungicides produced by trees in response to injury
– are the main source of energy for growth after injury
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Trunk & Branches • Contain the following:
– heartwood• is located in the center• is involved in the storage
and transport of energy• cannot respond to injury
– sapwood• as it ages, becomes the
toxic waste dump• gives the tree its natural
resistance to decay
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Trunk & Branches– pith
• is a spongy, foam-like material• is the main tissue formed as a twig
grows in length• is eventually covered by wood
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Branches • Are grown through the following process:
– starts at the auxiliary buds found at the leaf joint
– reproducing cells contained in the meristem, located at the tip of the bud, divide and become a twig
– cells located just under the bark divide and the twig grows in diameter, producing a branch
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Roots • Provide the following functions:
– uptake of water, minerals and oxygen– transport of water and minerals to the
trunk of the tree– tree support
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Roots • Take in water and minerals from the soil through
the root hairs called one-celled projections • Carry water to the trunk through conducting roots• Provide support through lateral brace roots
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Tree FactA large tree can have over 30 miles
of roots and five million root tips.
Estimating the Age of a Tree
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Estimating the Age of a Tree
• Includes the following steps:– measure the circumference of the tree– determine the diameter and radius of the tree– adjust for the width of the bark– determine the width of annual rings– determine the estimated age
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Tree Circumference • Is the measurement of the outside of a
tree trunk• Is measured 4.5 feet above the ground
with a measuring tape
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Measuring Tree Diameter
• Diameter– is the measurement of the thickness
or width of the trunk– is determined by the following
equation:• diameter = circumference/pi• pi = 3.14
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Measuring Tree Radius
• Radius– is the measurement of the exact
center of the trunk to the outside edge
– is determined by the following equation:• radius = diameter/2
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Adjusting Width of the Bark
• Subtract 0.5 inches from the radius of thinly barked trees
• Subtract 1 inch from the radius of a tree with thick bark
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Width of Annual Rings
• Can vary between trees due to the following:– genetics– climatic conditions– water and nutrient availability– disease – height– age
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Determining Width of Annual Rings
• Is calculated by performing the following steps:– measure the radius using a cross section of a tree
of similar species– count the number of annual rings within the radius– divide the radius by the number of annual rings
• width = radius/number of annual rings– the result is the average width of one annual ring
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Determining the Estimated Age
• Is calculated by the following equation:– radius/average width of annual
ring = estimated tree age
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Taxonomy
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Taxonomy• Was first used by Carl Linnaeus
in the 1700s• Uses a system of binomial
nomenclature– scientific names consists of
the genus and specie name– the genus name is capitalized,
the specie name is lowercase and both are italicized
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Binomial nomenclature:The scientific naming of species in which each organism is given two
names
Taxonomy • Includes the following classifications
in order from largest to smallest:– kingdom– division– class– order– family– genus– species
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Taxonomy Pneumonic device:
King David Came Over For Green Spaghetti
i i l r a g p
n v a d m e e
g i s e i n c
d s s r l u i
o i y s e
m o s
n
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Dichotomous Keys
• Are tools which aid in determining the identity of living things
• Always consists of two choices in each step– user is asked a pair of
questions– each question is designed to
divide into smaller groups until there is only one left 37
Dichotomous Key Example
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1. a. wings covered by an exoskeleton…………………. ….…..go to step 2
b. wings not covered by an exoskeleton………………...……….go to step 3
2. a. body has round shape……………...…………………..lady bug
b. body has elongated shape………..…...…….…………..grasshopper
3. a. wings point out from the side of the body………………………………...…..dragonfly
b. wings point to the posterior of the body…………………………….………..horsefly
Dichotomous Tree Key
• Identifies the tree by calculating the differences and similarities
• First separates the tree based on whether it is coniferous or deciduous– coniferous: possesses
cones– deciduous: sheds its leaves
each year
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Dichotomous Tree Key
• Then separates the tree based on the following properties:– leaf arrangement– leaf type – leaf shape– leaf margins– leaf tips– leaf bases– leaf vein types 40
Leaf Arrangement
41opposite
alternate
whorled
Leaf Type:Simple
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bipinnate
pinnate
palmate
Leaf Type:Compound
Leaf Shape
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linear
lanceolate
ovatecordate
obovate
Leaf Margins
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entire
crenate
dentate
sinuate
serrate
lobed
Leaf Tips
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Acute
Acuminate
Cuspidate
Obtuse
Truncate
Caudate
Aristate
Mucronate Retuse
Emarginate
Leaf Bases
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Acute Cuneate Rounded
Sagittate Hastate Truncate
Cordate Heart-shaped Oblique
Leaf Vein Types
48parallel
pinnate
palmate
Dichotomous Tree Key
• Then divides the tree based on the presence of twigs and buds
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Dichotomous Tree Key
• Fourth, divides the tree based on the presence of fruit
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Dichotomous Tree Key
• Includes, but is not limited to, the following characteristics:– bark– tree shape– habitat found where growing
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Summary• Dendrology involves the study of woody
plants including trees, shrubs and vines.• Tree anatomy consists of leaves, trunks,
branches and roots.• The estimated age of a tree is calculated
through the equation: estimated tree age = radius/average width of annual ring
• A dichotomous key identifies tree species in order to place a tree in a taxonomy classification. 52
Assessment1. Define dendrology.
2. Name the three types of woody plants.
3. ________ _________ is the home of the younger trees.
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Assessment4. Name the major parts of a tree.
5. Leaves take in oxygen through openings called buds.
a. true
b. false
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Assessment6. Name a function of bark.
7. Name the two leaf types.
8. Name a function of roots.
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Assessment9. Taxonomy was first used by Carl
Linnaeus.
a. true
b. false
10. Name the taxonomy classifications from largest to smallest.
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References • www.ci.huntsville.al.us• www.campgradyspruce.org • www.scarborough.k12.me.us• nerds.unl.edu• www.delawareenvirothin.org/Dendrology
Acknowledgements
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