Ch. 6 Structure and Growth

1. Ch. 6Structure and Growth • Tree form • Shoots • Primary growth • Stems • Primary and secondary growth • Roots • Primary and secondary growth • Leaves • Primary growth

2. Tree Form &Crown Shape

3. Tree Form Size, shape, and composition (# of branches, twigs, etc.) of the crown.

4. Open Growth

5. Restricted Growth(even walls)

6. Restricted Growth(uneven walls)

7. defined central bole narrow, columnar crowns associated with high latitudes or xeric sites more examples in Fig. 6.1 red spruce loblolly pine juniper Douglas fir Excurrent Crown Shape

8. Conifer Branch Angle • Controlled by: • Hormones • Light

9. also called ‘deliquescent’ spreading crown often has multiple stems most common form is ovate to elongate more examples in Fig. 6.1 white elm black willow Decurrent Crown Shape

10. apical bud lateral bud Control of Crown Shape • Hormonal control (or lack thereof) • Control of apical buds over lateral buds • Environment • Stand density

11. Competition & Crown Shape

12. Fig. 8.5 – Competition & Crown Shape

13. Ch. 6Structure and Growth • Tree form • Primary growth • Stems • Primary and secondary growth • Roots • Primary and secondary growth • Leaves • Primary growth

14. Seasonal Growth Patterns - Temperate Regions - • Dependent upon: • Fixed vs. Free growth • Fixed growth = buds form one year, grow the next • Free growth = concurrent initiation & growth • Environmental conditions • Daylength • Temperature • In Montana • Drought • Cold • Daylength

15. Seasonal Growth Patterns- Tropical Regions - • Dependent upon: • Leaf senescence • Leaf/root imbalance due to water stress

16. Why prune a tree? • Important for • Fruit trees • Christmas trees • Ornamentals (shaping, e.g. bonsai trees)

17. After Zimmermann & Brown, 1971 Fig. 6.5 – Tree GrowthGeorgia Piedmont

18. Fig. 6.4 – Tree Growthseasonally dependent

19. Douglas fir (Montana) Height Southern Pines Cottonwood 50 100 25 Age (years) Tree Growth(live fast, die young)