1. Tree Growth Unit 10

2. 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

3. 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?

4. How Does A Tree Grow MERISTEM tissue in the Bud--crown
Root tips--roots
Cambium--trunk
From the MSU AGRSCIENCE WEB PAGE

5. Roots
Apical MERISTEM protected by a root cap (cells divide and differentiate)
Permanent roots—anchorage
Feeder roots
Root hairs—water and nutrient absorption

6. 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
ROOTS COVER 4 TO 7x THE CROWN AREA
From the MSU AGRSCIENCE WEB PAGE

7. 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)
Mycorrhizal association root fungus structures Mycorrhizae to increase absorptive area, especially for potassium, 2500 known
From the Iowa State University Forestry Extension

8. 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

9. *Sapwood Heartwood Outer Bark Phloem Cambium Xylem
From the MSU AGRSCIENCE WEB PAGE

10. From the MSU AGRSCIENCE WEB PAGE

11. From the University of Georgia School of Forestry

12. From the MSU AGRSCIENCE WEB PAGE

13. 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

14. Factors Affecting Ring Growth
From the University of Georgia School of Forestry

15. 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

16. 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)

17. 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

18. 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)