Tree Growth Topic 1114

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Tree GrowthTopic 1114

• Mr. Christensen

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Objectives

• Learn how woody plants grow
• Know where growth occurs in a tree
• Understand the relationship of tree ring growth
  and environmental conditions
• Describe limiting factors for tree GROWH

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How Does A Tree Grow

• MERISTEM tissue in the
• Bud--crown
• Root tips--roots
• Cambium--trunk

From the MSU AGRSCIENCE WEB PAGE
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Roots

• Apical MERISTEM protected by a root cap (cells
  divide and differentiate)
• Permanent rootsanchorage
• Feeder roots
• Root hairswater and nutrient absorption

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Roots

• Absorbing roots are concentrated in the top 6-18
  inches of soil (water, nutrients and oxygen)
• Roots cover 4 to 7 times the area of the crown

From the MSU AGRSCIENCE WEB PAGE
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Tree Root Classes

• Heart root (red oak, honey locust, basswood,
  pines)
• Tap root (hickory, walnut, butternut, white oak
  and hornbeam)
• Flat root (birch, fir, spruce, sugar maple,
  cottonwood and silver maple)

From the Iowa State University Forestry
Extension http//www.ag.iastate.edu/departments/fo
restry/ext/pubs/F-308.pdf
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Trunk

• Growth in diameter of plants is due to cell
  division in the cambium
• Located just under the bark
• Insidexylem conducts water and nutrients
• Outsidephloemtransports sugars, amino acids,
  vitamins, hormones and stored food

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Sapwood
Heartwood
Outer Bark
Phloem
Cambium
Xylem
From the MSU AGRSCIENCE WEB PAGE
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From the MSU AGRSCIENCE WEB PAGE
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From the University of Georgia School of
Forestry http//www.forestry.uga.edu/warnell/serv
ice/library/index.php3?docID172
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From the MSU AGRSCIENCE WEB PAGE
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Wood Types

• Spring wood (early wood)
• Summer wood (late wood)
• Heart woodold xylem tissue (provides structure
  and infection resistance)
• Sapwoodliving xylem active in fluid transport
• Phloeminner bark nutrient transport, outer
  barkdead phloem

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Factors Affecting Ring Growth
From the University of Georgia School of
Forestry http//www.forestry.uga.edu/warnell/serv
ice/library/index.php3?docID172
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Crown

• Budsapical MERISTEM 3 types
• Mixedshootsleaves and or flowers
• Leaf buds
• Shoot buds
• Terminal buds--apex of MERISTEM (trunk)
• Lateral budsbranches and flowers

From Iowa State University Forestry Extension
Notes F-308 www.ag.iastate.edu/departments/forest
ry/ext/pubs/F-308.pdf
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Types Of Buds

• Fixed growththe number of leaves and nodes for
  next year is fixed by this years resource
  availability (length of nodes is dependent on
  next years conditions (pine, oaks hickory)
• Free growthbuds containing leaves are preformed
  but additional leaves can be added depending on
  that years CONDITONS (cottonwood, willow, and
  silver maple)

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Tree Form

• EXCURRENTstrong apical dominance (conicalpines)
• DECURRENTlack of strong apical
  dominancedeliquescent (large spreading crowns)

From Iowa State University Forestry Extension
Notes F-308 www.ag.iastate.edu/departments/forest
ry/ext/pubs/F-308.pdf
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What Have We Learned Today

• Learned tree growth occurs in Meristem tissue of
  Roots (tip), trunk (cambium) and crown (buds)
  (Down, Out and Up)
• Water is the most restrictive factor affecting
  tree growth (Light, Temperature and Relative
  humidity)