Clonal Deployment Revisited Results from a simulation model to minimise risk

1. Clonal Deployment RevisitedResults from a simulation model to minimise risk for both a known and unknown future pest Alvin Yanchuk1, John Bishir2 John Russell1 and Ken Polsson1 1. BC Forest Service 2. NC State Univ

2. Introduction • Libby (1982), Roberds et al (1990) • single gene models, plantation failure • more than 30 clones does not provide any advantages • sometimes 1 is best

6. Introduction • Issues to consider: • growth and yield • deployment patterns • current known and future unknown threats • disease &pest resistance - evolutionary concerns

7. Objectives • maximize volume at rotation • number of clones deployed • planting patterns • current and future pest threat • environmental attributes

8. Methods • Tree and Stand Simulator (TASS - B.C. For.Ser.) • individual stems, competition-driven • Spruce weevil and clonal deployment model • plants trees using different deployment scenarios • tree resistance mechanisms • spruce weevil movement, dynamics, damage • impact on growth and yield (interaction with TASS)

9. Deployment numbers & patterns • Numbers of clones • 2, 6, 18 and 30 • Deployment strategies • Random Mix (RM) • Single Clonal Blocks (SCB) • Mosaic of Clonal Blocks (MCB)

10. Random Mixes

11. Random Mixes

12. Single Clone Blocks

13. Mosaic of Clonal Blocks - 2 clones

14. Mosaic of Clonal Blocks - 6 clones

15. Weevil Parameters • weevil introductions into plantations • each tree starts with 2 weevils • 6 weevils / tree on 6 corner trees • no weevils

16. Environmental Parameters • two average annual temperatures (7 C and 11 C) • two site indices (24 and 30) • two sizes (1 and 5 hectares)

17. Clones • Fixed • known pest • resistance mechanisms • Random • unknown future threat

18. Clonal Parameters • ATR - attractiveness (volatile) • 10=extremely attractive • RES - rate of resin flow rate • 10 = maximum flow • TOX - toxicity of resin • 10=100% toxic

19. Clonal Parameters • GRW - tree ‘vigour’ • -grown in absence of weevil • h2=1.0 for ATR, RES, TOX • h2=0.5 for GRW • GRW correlated with RES (rg=0.5)

20. Parameters of resistance for fixed clones • three clonal scenarios: • 1) 2 clones:1 & 2 • 2) 6clones: 1 to 6 • 3) all 18 clones • attempted to have: • good growth • various resistance combinations

21. Random Clones (Unknown Future Threat) • clones drawn randomly from normal distribution • RES,TOX,ATR:  =0.5,  =1.5 • GRW:  =1.0,  =0.1 • up to 30 runs per scenario

25. 18 fixed clones (WD=1, TMP= 11, SI=30, Ha=1)

28. Top 50% clones=85% volume Ne reduction 20%

31. Conclusions • range of ‘acceptable’ numbers of clones, between 6-18 • random mix was always the best • most elite genotype will do most of the work • effective population sizes change only by ~20% • current BC policy of Ne = 20 tested clones

32. Conclusions • Changes in other model parameters minimal effects: • temperature differences • 1 vs 5 ha • insect “introduction” patterns • site index

33. Conclusions • Additional questions that remain: • deployment across the landscape

35. Conclusions • Additional questions that remain: • deployment across the landscape • allelic model for resistances (MGR) • clonal ideotypes /among and with clone competition -full-sib family deployment