tree growth unit 10
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Tree Growth Unit 10. 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 GROWTH. Question. - PowerPoint PPT PresentationTRANSCRIPT
Tree GrowthUnit 10
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 GROWTH
Question
• If I were to hammer a nail into a tree 3 feet off the ground and the tree grows 1foot per year. In 25years how far off the ground will the nail be?
How Does A Tree Grow• MERISTEM tissue in the • Bud--crown• Root tips--roots• Cambium--trunk
From the MSU AGRSCIENCE WEB PAGE
Roots
• Apical MERISTEM protected by a root cap (cells divide and differentiate)
• Permanent roots—anchorage
• Feeder roots
• Root hairs—water and nutrient absorption
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
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 Extensionhttp://www.ag.iastate.edu/departments/forestry/ext/pubs/F-308.pdf
Trunk
• Growth in diameter of plants is due to cell division in the cambium
• Located just under the bark• Inside—xylem –conducts water and
nutrients• Outside—phloem—transports sugars,
amino acids, vitamins, hormones and stored food
Heartwood
XylemCambium
PhloemOuter Bark
From the MSU AGRSCIENCE WEB PAGE
*Sapwood
From the MSU AGRSCIENCE WEB PAGE
From the University of Georgia School of Forestry http://www.forestry.uga.edu/warnell/service/library/index.php3?docID+172
From the MSU AGRSCIENCE WEB PAGE
Wood Types
• Spring wood (early wood)• Summer wood (late wood)• Heart wood—old xylem tissue (provides
structure and infection resistance)• Sapwood—living xylem active in fluid
transport• Phloem—inner bark nutrient transport,
outer bark—dead phloem
Factors Affecting Ring Growth
From the University of Georgia School of Forestry http://www.forestry.uga.edu/warnell/service/library/index.php3?docID+172
Crown• Buds—apical MERISTEM 3 types
• Mixed—shoots—leaves and or flowers
• Leaf buds
• Shoot buds
• Terminal buds--apex of MERISTEM (trunk)
• Lateral buds—branches and flowers
From: Iowa State University Forestry Extension Notes F-308 www.ag.iastate.edu/departments/forestry/ext/pubs/F-308.pdf
Types Of Buds
• Fixed growth—the 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 growth—buds containing leaves are preformed but additional leaves can be added depending on that years CONDITONS (cottonwood, willow, and silver maple)
Tree Form
• EXCURRENT—strong apical dominance (conical—pines)
• DECURRENT—lack of strong apical dominance—deliquescent (large
spreading crowns)
From: Iowa State University Forestry Extension Notes F-308 www.ag.iastate.edu/departments/forestry/ext/pubs/F-308.pdf
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)