Forestry Science I Unit 3 Lesson 2

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Forestry Science IUnit 3Lesson 2

• Created by Ms. Holli Bowman
• FORS 7730
• Fall 2001

Modified by Georgia Agricultural Education
Curriculum Office July 2002
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Annual Rings

• Annual rings are formed by division of the
  cambium layer
• Each ring is composed of two cell walls
• Summerwood -- a darker-colored area of small,
  dense, heavy walled cells
• Springwood -- a lighter-colored area of large,
  thin-walled cells.

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Annual Rings

• Annual rings vary in width for several reasons
• amount of room tree has to grow -- how close it
  is to other trees
• Rainfall amounts
• Drought
• Natural Disasters (fire, insect damage, etc)

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Annual Rings

• False ring -- a false ring may be formed when
  very favorable growing conditions may occur when
  a tree is growing slowly which may result in an
  additional ring of wood in a given year.
  Characteristic of pines and some broadleaf trees.
• Tolerance -- the ability of a tree to endure
  shade.

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Tree Reproduction

• Trees reproduce in three ways
• by seed
• by sprouts
• by suckers
• Seed is the most common way for a tree to
  reproduce.
• Broadleaf trees sprout profusely.
• Suckering is the sending up of shoots from
  underground roots.

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Seed and Flower Production

• Fruits and seeds are NOT the same.
• In hardwood trees, a fruit is usually the ripened
  ovary of a flower.
• The ripened ovules of the ovary are the seeds of
  the fruit.
• Monoecious species -- if the male and female
  flower parts occur in separate flowers on the
  same tree
• Dioecious species -- if the male and female
  flowers occur on separate trees

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Parts of the Flower

• Ovary -- the enlarged portion at the base of the
  pistil.
• Ovules -- parts of the ovary that, when ripened,
  comprise the seed of the fruit.
• Calyx -- the sepals of the flower, when grouped
  as one part.
• Corolla -- the petals of the flower, when grouped
  as one part.
• Pistil -- the female portion of the the flower,
  consists of the stigma, the style and the ovary.
• Stamen -- the male part of the flower, consists
  of the anther and the filament.

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Types of Flowers

• Complete Flower -- a flower which contains all
  parts
• Incomplete Flower -- a flower which lacks one or
  more of the following a calyx, corolla, stamen,
  or pistil

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Pine seed definitions

• The ovules of conifers are born naked on cone
  scales and are not enclosed in an ovary.
• Carpelate -- female cones which pine seeds are
  produced on.
• Sacs -- clusters of staminate pollen-bearing
  cones.
• Most pine species require two years for the seed
  to mature.

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Seed Dispersal

• Seeds are dispersed by several means
• Wind
• Birds
• Animals
• Streams / Other water
• Humans
• Simply falling to the ground