1. FRST 305 Photosynthesis, Respiration, Crown development and Wood formation

2. Photosynthesis Chlorophyl in the foliage Chloroplasts Sun foliage/shade foliage

3. Photosynthesis 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6 O 2 SUNLIGHT

4. Photosynthate C 6 H 12 O 6 “Stuff” Energy

5. Respiration C 6 H 12 O 6 CO 2 + H 2 O + O 2 (Not balanced) ENERGY

6. Priorities for Photosynthate 1.Respiration 2.Foliage – Fine Roots 3.{Reproduction} 4.Primary Growth 5.Secondary Growth – Secondary Compounds

7. Photosynthesis > Respiration ? –GROW Photosynthesis < Respiration ? –DIE Photosynthesis = Respiration ? –NOT A LONG TERM CHOICE

8. Volume Wood formation (total volume) is: [ (Photosynthesis-Respiration)] - Allocation

9. Where Does It Go? Respiration Increment Dominant Tree26% 42% Co-dominant Tree29% 41% Suppressed Tree50% 8% [ash stand in Denmark]

10. Crown Form Excurrent Decurrent

11. Mechanisms Branch angle Geotropism Weight (gravity)

12. Apical Growth Apical meristem = bud –Primary growth Preformed Indeterminant

13. Epinasty Epinastic control –angle and length of side branches –genetics and environment

14. Shade Side shade –Trees do not lose form Shade from above –high shade – low shade –becomes more diffuse –trees can lose epinastic control

16. Cross section

22. Secondary Growth Wood Phloem Stem and branches Cambium

23. Cambial meristem Xylem –To the inside Phloem –To the outside

24. Xylem and Phloem Xylem –Wood –Water transport Phloem –Chemical transport

25. Xylem Tracheids –gymnosperms Vessels –angiosperms

26. Early wood – Late wood Early wood –Laid down first –Lighter –Less dense Late wood –Laid down later –darker in color –denser

27. Ring Widths Crossectional area Matter of geometry Distance from crown Mechanical stimulation

28. Stem Form Ring Area

29. Stem Form Ring Width

30. Priorities for Photosynthate 1.Respiration 2.Foliage – Fine Roots 3.{Reproduction} 4.Primary Growth 5.Secondary Growth – Secondary Compounds

31. Which are better? A.Cylindrical trees B.Tapered trees

32. Taper

33. Reaction wood Hardwoods –Tension wood Conifers –Compression wood

34. Compression Wood

35. Compression wood

36. Knots Live knots Dead knots

37. Live Knots – Dead Knots

40. Stem Quality Straightness Ring characteristics Density Knots