Forestry Science Day 2
Ms. Dombroski
August 2005
http://www.cpluhna.nau.edu/images/mixedconifer.jpg
• What is a Tree?
A woody plant
having one welldefined stem and
a formal crown.
Also, a tree
usually attains a
height of 8 feet.
http://www.flmnh.ufl.edu/anthro/caribarch/images/danceiba.jpg
Tree Parts
What are the Three Main parts of a
tree and What are Their Functions?
1. Crown: Manufactures food
2. Stem: Transports food, minerals, &
water up and down the plant
3. Roots: Absorb water and minerals and
transport them up through the
stem to the crown.
Main Parts
of a Tree
Stem Parts
What are the parts of the stem and their
functions?
• Heartwood: Dead wood located in the center
of the stem. Provides strength to the tree.
• Phloem: Food conducting tissue
• Xylem: Supporting and water-conducting tissue
Stem Parts
• Cambium: An active layer of cells located
between the xylem and phloem.
Responsible for the annual growth of
the tree.
• Sapwood: Newly formed wood between cambium
and the heartwood
• Bark: Outer surface that protects the
cambium, phloem, and xylem.
Growth Rings
• Springwood - Young,
usually soft wood that
lies directly beneath
the bark and develops
in early spring.
http://www.idahoforests.org/img/cookie2.gif
Division of Cambium = Rings
• Summerwood produced during the
latter part of the
growing season and is
harder and less porous
than springwood.
Tree Cookies!
• In groups of two you will need;
–
–
–
–
–
A handout and writing utensil
A tree cookie
5 pins
5 pieces of tape
You will be sharing, diameter tape and Biltmore
sticks
Why do Annual Rings vary in Width?
1. Competition for necessities
2. The amount of supply
3. Human interruption – selective cutting
4. Natural Disasters - fires, insect damage, etc.
Tree Canopy
• What is the main function
of the canopy?
What is the Process of
Photosynthesis?
• The process whereby carbohydrates
(sugars and starches) are manufactured in
the leaves of green plants using water,
carbon dioxide, and in the presence of
sunlight.
6H2O + 6CO2 ----------> C6H12O6+ 6O2
http://www.cafeaulait.org/course/week9/sun.gif
http://www.caribbeanedu.com/images/kewl/photosynthesis.gif
What's in the Tree Crown?
• Monoecious flowers
contain both the male
and female reproductive
parts.
• Dioecious flowers the
male and female flower
parts are produced on
separate trees
• Complete flower?
Contains pistil, stamen,
sepals and petals
(monoecious)
• Incomplete flower?
A flower that lacks a
specific part; a pistil,
stamen, sepals, or
petals (dioecious)
Parts of
the
Flower
http://www.ecy.wa.gov/programs/wq/plants/plantid2/images/flowerwes.gif
Flower Dissection Lab
• In groups of two you will need;
–
–
–
–
–
–
–
–
One handout, writing utensil
One flower
One tweezers
One blunt/sharp scissor
Microscope slide and cover slip
Several pins
Tape
One dissection tray
How do Trees Reproduce?
1. Seeds –
Most trees reproduce by
this method
2. Sprouts
3. Suckers
http://www.colostate.edu/Depts/CoopExt/4DMG/images/sucker2.jpg
What about Seeds?
• PARTS
• TYPES
1. Seed coat - protection
1. Monocotyledon:
Flowering plants (grasses,
2. Embryo – organism in
orchids, and lilies) having
early development
a
single
cotyledon
in
the
3. Stored food
seed.
a. Endosperm: Nutritive
tissue of flowering plants
2. Dicotyledon: A
b. Cotyledons: first pair
flowering
plant
with
two
of leaves to emerge
embryonic seed leaves
Parts of the Seed
3 Main Types of Roots
• Tap - large and fleshy, grow deep, able to store food
(necessary for perennial plants), mostly found in
dicotyledons
• Fibrous - close to the surface collects precipitation,
combine efforts with TAP to maximize efficiency, mostly
found in monocotyledons
• Adventitious - help plants climb; ivies, modified
underground stems; bulbs, common in both dicots and
monocots
ANY EXAMPLES
Tap: Fruit trees
Fibrous:
Trillium
Adventitious:
Lily of the Valley