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Estimation of Genetic Multipliers for Douglas-Fir Height- and Diameter-Growth Models Peter J. Gould, David D. Marshall, Randy Johnson and Greg Johnson. Study Objectives.
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Estimation of Genetic Multipliers for Douglas-Fir Height- and Diameter-Growth Models Peter J. Gould, David D. Marshall, Randy Johnson and Greg Johnson
Study Objectives 1. Estimate growth differences between average (wood’s-run) tree and individual families in terms of genetic-gain multipliers.2. Relate multipliers to breeding value (BV = percent gain at age 10).3. Evaluate multipliers effects in model.
Effect of Multipliers Initial Size Advantage Gain Multiplier= 0.05 Typical Tree
SET 1 SET 2 SET 3 Rep 1 Rep 1 Rep 1 Rep 2 Rep 2 Rep 2 Rep 3 Rep 3 Rep 3 Rep 4 Rep 4 Rep 4 NWTIC 1st-Generation Progeny Tests Coop: breeding zone. Completely independent families.Sites: Geographical locations within coops.
DBH Data: Variation between Coops 10-YR GROWTH PERIOD
DBH Data: Variation between Sites 10-YR GROWTH PERIOD
DBH Data: Variation between Sets 10-YR GROWTH PERIOD
DBH Data: Breeding Values BV = Age 10 Gain 1 (percent)
Modeling Strategy: Assumptions 1. Average growth = wood’s run.2. Multipliers work with any unbiased growth model.3. Removing sources of variation other than genetics is very important.
Strategy:1. Fit models with random effects at site-set level.2. Calculate genetic multiplier (m) for each family at coop level. Obs = m ∙ Pred3. Estimate m from BV. m = A0 + A1 ∙ BV
10-YR Modeling Dataset: HT Model >16 coops> 109 sites> 513 site-sets> 2485 families> 222 818 observations
HT Model 1 ∆HT = b1∙HTb2∙b3HTrandom effects on b1,b2,b3Fixed Effects: ∆HT = 231.7∙HT0.94∙0.86HT
Modeling Datasets: DBH Model >7 coops> 45 sites> 193 site-sets> 1160 families> 76 012 observations
DBH Model 1 ∆DBH = b1∙DBHb2∙b3DBH∙b4BA REPrandom effects on b1,b2,b3Fixed Effects: ∆DBH = 3.7∙DBH0.3∙1.01DBH∙0.97BA REP
Other Periods • Ht data for 5-yr (167,000 obs) and 15-yr (7600 obs) growth. • DBH data for 5-yr (7,700 obs) and 15-yr growth (20,000). • Estimates of m are higher for 5-yr, but about the same for 15-yr growth.
What’s Next? • Manuscript on multipliers. • ORGANON interface. • Test multipliers.