1. Stem Exclusion

2. Objectives 1.Understand the patterns and processes within the stem exclusion stage 2.Understand when processes of crown closure and self-thinning occur 3.Understand difference between stratification and differentiation 4.Understand relationship behind these biological processes and stand tending operations

3. Stem Exclusion Number of trees goes down Live crown ratio goes down

4. Crown Closure Early in dense stands Later in less dense stands

5. Self-thinning Does not occur at crown closure Still adequate growing space per tree for growth No available growing space

9. Stratification Separation into layers (strata) Separation is by species or cohort

10. Differentiation Separation within stratum by vigor –Dominant –Co-dominant –Intermediate –Suppressed

11. Differentiation Slightly older Better microsite Less competition –Other vegetation –Wider spacing Genetically superior

12. Stem Reflection of history Accumulation of growth

13. Tending Speeds up natural process Directs growth onto certain trees Reallocates growth within tree Increases total growing space

14. Self-thinning Growing space is limited Repartitioning of growing space Trees must get bigger to live

15. Fixed amount of growing space Large number of small things Small number of big things Small number of small things – space left over

16. Concept SizeSize number X X

17. Concept SizeSize number

18. Concept SizeSize number X

19. Concept SizeSize number X

20. Concept SizeSize number

21. Concept Ln (size) number Ln (number)

22. Relative density Number of trees / maximum number –Of that size

23. Concept SizeSize number XY RDI = x/y