1. Juvenile Wood in Pines

2. Overview Basics Of Wood Production What Is Juvenile Wood Characteristics What influences Juvenile Wood What Are The Problems With It How To Manage It

3. Basics of Wood Production

4. Tracheids Structure Functions –Water transport in the xylem –Support –Storage

5. Growth Rings Trees produce two types of rings during the a growing season Spring Wood (early wood) Summer Wood (late wood)

6. What is Juvenile Wood

7. Where it is Found First set of growth rings extending out from the pith of the tree

8. When it is produced Is highly variable between species, stands, and individuals It is produced by all tree, but species and site location play a large part in determining its impact Can be between 3 to 20 years average of 10 years

9. Characteristics

10.  Growth rings Wide growth rings Ring Age Uniformity

11.  Tracheid characteristics –Wall thickness and tracheid diameter –Tracheid length –Angle  Growth rings

12.  Specific Gravity –Less summer wood in Juvenile wood –Much lower specific gravity  Growth rings  Tracheid characteristics

13. What influences Juvenile Wood

14. Competition Live crown Growth rate Geographic location

15. Problem

16. Strength Shrinkage Compression wood formation

17. Tanzania South African Forestry Journal – No. 172 March 1995 p 19-23 Indigenous lumber sources were insufficient for the needs of the country Plantation of Pinus patula 60,000 ha planted 49% of stems consisted of Juvenile wood

18. How to manage for Juvenile Wood

19. Stand density Initial spacing Spacing and thinning

20. Fertilization Increases foliar mass and photosynthetic ability Decrease in summer wood production and specific gravity Less pronounced in mature wood Promotes spring wood production

21. Irrigation Early application has same results as seen with fertilization Promotes spring wood production Late application prolongs cambial activity Promotes summer wood production

22. Removing Competing Vegetation Early removal promotes seedling growth Continued removal into the pole stage to reduce competition and increase growth, but promotes juvenile wood Juvenile wood produced for a longer period of time, but higher specific gravity

23. Summary Juvenile wood is in all trees, but can be a problem in rapid growing pine species It is influence by competition, live crown, growth rate and location It can be managed by controlling stand density, fertilization, irrigation, and managing competing vegetation