Abstract:
A method for selecting conifer trees is disclosed. This method relates to the early measurement of tree characteristics for selecting trees most likely to exhibit certain traits as they mature. This method can be used for implementing silvicultural treatments, thinning or further breeding.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a method for selecting conifer trees for improved volume, yield and wood quality. 
     BACKGROUND OF THE INVENTION 
     The growth attributes and physical characteristics of a conifer tree contribute to the value assessed that tree after a commercial harvest. Such value may be measured by the stem quality, volume of wood and wood quality measures such as strength and stiffness. The earlier these characteristics can be accurately assessed, the more a given site can be planted with trees that provide larger volume and more desirable wood characteristics per acre. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to a method for selecting conifer trees. Conifer trees grow well in many regions, including Douglas-fir in the Pacific Northwest region of the United States and loblolly pine in the Southeast region of the United States. In the Southern hemisphere, radiata pine grows well. 
     The method of the present invention may be used in selecting trees for breeding based upon characteristics measured in those trees using the methods of the present invention. By using more elite trees for breeding, one is able to plant trees which are more likely to provide higher volumes of wood and more desirable characteristics. 
     The method of the present invention may also be used for selecting against trees for silvicultural treatments. This may include thinning or removal trees not selected based upon characteristics measured using the methods of the present invention. 
     The method of the present invention may also be used for a combination of selecting elite trees for breeding and later use of the method for selecting among the resulting trees for silvicultural treatments. 
     The method of the present invention may also be used to select a group of trees having a range of a certain characteristic to provide diversity in a site. 
     One factor which may be measured in the present invention is sinuosity. Generally, sinuosity is measured as the amount of stem deflection from vertical plumb in the tree. Increased amounts of sinuosity in a tree causes warped grain that impacts the quality of lumber and percent of yield of lumber and pulp from that tree. 
     Another factor which may be measured in the present invention is ramicorn branching or cluster knots. A ramicorn branch is highly angled (usually less than 30° to the trunk or stem). 
     Ramicorn branching may result from second flushing or damage to the terminal bud. Cluster knots or double whorls may result from second flushes during the same growing season. Both ramicorn branching and cluster knots can reduce the yield and quality of lumber from a tree. 
     EXAMPLE 
     Douglas-fir trees were planted on three Weyerhaeuser sites, one near Longview, Wash. (LG), one near Twin Harbors, Wash. (TH), one in Vail, Wash. (VL) and one in the Cascade mountain range in Washington (CA). 
     The trees were obtained by breeding 71 parents that were a combination of first- and second-generation selections from three first-generation provenances: Cascade, Longview, and Twin Harbors. These select parent were then mated with 4 to 6 “tester” parents from first-generation selections to produce a total of 274 full-sib families. The Genetic Controls (GC) (n=40) were open-pollinated first-generation families that served as a basis of comparison between the first- and second-generation trials. The Field Checks (FC) (n=3) were genetically unimproved seed sources or reference populations used to gauge changes in growth and stem quality through genetic selection. 
     The full-sib families were arranged as single-tree plots in 6 randomized complete replications. Thus, each site included 6 trees per full-sib family. Genetic Controls were located in 6 sub-blocks within each replication on a site. Each Genetic Control family was represented by 4 single-tree non-contiguous plots within each sub-block. Field Checks were planted in three 99-tree sub-blocks. 
     Height, diameter, terminal and lateral second flushing, and sinuosity were measured annually from ages 4- to 9-years. Double whorls and ramicorn branching were measured annually from ages 5- to 9-years. Spring bud flush was assessed at 2- to 4-years. Weekly observations were made of the site and when about fifty percent (50%) of the trees had flushed, bud flush was noted and trees were recorded as being early or later spring bud flush trees. 
     More intensive branch measurements were made on a sub-set of trees at each test site. 
     These measurements included branch number and angle, total knot area, and the percentage of fall growth due to second flushing. This sub-set of trees included 30 unrelated parents from 4 of the 6 replications as well as all the trees in 4 of the 6 Genetic Control sub-blocks and 1 of the 3 Field Check sub-blocks. 
     Final stem quality was assessed in 9-year-old trees in 4 of the 6 replications and retrospectively measured annual leader length, second flushing, ramicorn branching, and sinuosity. Results were averaged across years. 
     
       
         
               
             
               
               
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Descriptions of traits measured and number of observations 
               
               
                 in the 3 generations of test trees pooled across the four test sites. 
               
             
          
           
               
                   
                 Number of trees 
                   
               
             
          
           
               
                 Trait 
                   
                 Genetic 
                 Field 
                 Trait 
               
               
                 Abbreviation 
                 Full-sib 
                 Control 
                 Check 
                 Description 
               
               
                   
               
             
          
           
               
                 Tree Improvement measures 
               
             
          
           
               
                 H8 
                 6293 
                 898 
                 923 
                 (dm) 
               
               
                   
                   
                   
                   
                 Tree height at 8-years. 
               
               
                 D8 
                 6293 
                 898 
                 923 
                 (mm) 
               
               
                   
                   
                   
                   
                 Tree diameter at breast height (1.3 m) at 8- 
               
               
                   
                   
                   
                   
                 years. 
               
               
                 V8B 
                 6293 
                 898 
                 923 
                 (dm 3 ) 
               
               
                   
                   
                   
                   
                 Bole volume at 8-years. 
               
               
                 BudFlush2-4 
                 6644 
                 947 
                 958 
                 Phenology: 1 = flushed terminal bud. Average 
               
               
                   
                   
                   
                   
                 based on annual assessments at 2- to 4-years 
               
               
                   
                   
                   
                   
                 when 50% of trees on a site begin spring 
               
               
                   
                   
                   
                   
                 budflush (approximately mid-May). 
               
               
                 Terminal5-9 
                 5711 
                 791 
                 822 
                 Stem quality: 1 = second flushed terminal bud. 
               
               
                   
                   
                   
                   
                 Average of annual assessments from 5- to 9- 
               
               
                   
                   
                   
                   
                 years. 
               
               
                 Lateral6-9 
                 6377 
                 913 
                 938 
                 Stem quality: 1 = second flushed lateral bud. 
               
               
                   
                   
                   
                   
                 Average of annual assessments from 6- to 9- 
               
               
                   
                   
                   
                   
                 years. 
               
               
                 Sinu5-9 
                 6347 
                 902 
                 932 
                 (inches) 
               
               
                   
                   
                   
                   
                 Stem quality: Sinuosity or the amount of stem 
               
               
                   
                   
                   
                   
                 deflection from vertical plumb. Average of 
               
               
                   
                   
                   
                   
                 annual assessments from 5- to 9-years. 
               
               
                 DWhorl6-9 
                 6377 
                 913 
                 938 
                 Stem quality: 1 = Double whorl or second 
               
               
                   
                   
                   
                   
                 whorl of branches from second flushing. 
               
               
                   
                   
                   
                   
                 Average of annual assessments from 6- to 9- 
               
               
                   
                   
                   
                   
                 years. 
               
               
                 Rami6-9 
                 6322 
                 904 
                 934 
                 Stem quality: 1 = one or more ramicorn 
               
               
                   
                   
                   
                   
                 branches from second flushing. Average of 
               
               
                   
                   
                   
                   
                 annual assessments from 6- to 9-years. 
               
             
          
           
               
                 Tree Improvement intensive branch measures 
               
             
          
           
               
                 BranchNumber 
                 880 
                 294 
                 621 
                 Total number of branches &gt;5 mm diameter in 
               
               
                   
                   
                   
                   
                 whorl and internode immediately above breast 
               
               
                   
                   
                   
                   
                 height. 
               
               
                 BranchAngle 
                 880 
                 294 
                 621 
                 Average branch angle in the whorl immediately 
               
               
                   
                   
                   
                   
                 above breast height. Range was 15° to 37° 
               
               
                   
                   
                   
                   
                 above horizontal. 
               
               
                 KnotArea 
                 880 
                 294 
                 621 
                 Total cross-sectional area of all branches 
               
               
                   
                   
                   
                   
                 calculated from total number of branches 
               
               
                   
                   
                   
                   
                 multiplied by the average diameter of branches 
               
               
                   
                   
                   
                   
                 in the whorl and internode immediately above 
               
               
                   
                   
                   
                   
                 breast height. 
               
               
                 FallGrowth 
                 880 
                 294 
                 621 
                 Percent of annual height increment due to 
               
               
                   
                   
                   
                   
                 second-flushing. Measured on internode 
               
               
                   
                   
                   
                   
                 immediately above breast height. 
               
             
          
           
               
                 Silviculture measures 
               
             
          
           
               
                 Leader5-9 
                 4248 
                 594 
                 929 
                 (dm) 
               
               
                   
                   
                   
                   
                 Average of annual height increments from 5- to 
               
               
                   
                   
                   
                   
                 9-years. Assessed retrospectively at 9-years. 
               
               
                 SilvFlush3-9 
                 4248 
                 593 
                 929 
                 Stem quality: 1 = branch or internode with 
               
               
                   
                   
                   
                   
                 second-flush. Average from 3- to 9-years 
               
               
                   
                   
                   
                   
                 assessed retrospectively at 9-years. 
               
               
                 SilvRami3-8 
                 4248 
                 593 
                 929 
                 Stem quality: 1 = presence of one or more 
               
               
                   
                   
                   
                   
                 ramicorn branches. Average from 3- to 8-years 
               
               
                   
                   
                   
                   
                 assessed retrospectively at 9-years. 
               
               
                 SilvSinu3-9 
                 4248 
                 592 
                 929 
                 (inches) 
               
               
                   
                   
                   
                   
                 Stem quality: Sinuosity or the amount of stem 
               
               
                   
                   
                   
                   
                 deflection from vertical plumb. Average from 
               
               
                   
                   
                   
                   
                 3- to 9-years assessed retrospectively at 9- 
               
               
                   
                   
                   
                   
                 years. 
               
               
                   
               
             
          
         
       
     
     Eight-year height was used to eliminate outlier trees from the dataset. Outliers were defined as those with heights that were more than three standard deviations below the average for the site. 
     Individual tree data was pooled across the four test sites and the data was analyzed with the AS Reml statistical package (available from VSN International Ltd. having an address of 5 The Waterhouse, Waterhouse Street, Hemel Hempstead, Herts, UK HP1 1ES) which fits linear mixed models using restricted maximum likelihood. Factors fitted included the fixed effect of site, the random effects of replicate within test site, the additive effect of each tree as estimated from its phenotype, the numerator relationship matrix, and family effects. Models were fitted both with and without the inclusion of the origin term or parent provenance to determine the origin effect on heritability estimates. 
     The ASReml model was equivalent to:
 
Trait i.j.k.l.m   =mu +test i (+Origin m )+(replication:test) ij +family k +tree l +residual i.j.k.l.m   II
         Trait ijkl  represents the phenotypic value of an individual tree (tree l) for the trait under analysis;   mu is the fitted overall mean for the trait across all four tests;   test i  is the effect of the i th  test site (considered to be a fixed effect);   Origin m  is the effect of the m th  origin (also fixed);   replication:test ij , the effect of the j th  block replication within each i th  test site;   family k , the non-additive effect specific to the cross that produced full-sib progeny l. A model was utilised that allowed this effect to be fitted to Set 1 (full-sib) progeny but not Set 2 (half-sib) progeny, as it is assumed that half-sib families do not contain a systematic effect for specific combining ability;   tree l , the additive genetic effect of tree l; and   residual ijkl , the residual error associated with tree l, assumed to be independent of the test site on which tree l is growing.       

     The additive genetic relationship matrix describes all known relationships among trees, parents and other ancestors, and its inverse elements augment the equations representing a tree&#39;s genetic effect. The additive genetic variance, dominance variance and individual heritability were estimated. 
     In an individual tree model, the additive genetic variation (σ 2   A ) is given directly by the variance among trees, estimated from all phenotypic information, taking into account known genetic relationships and all other effects in the model. 
     The variance of family deviations, denoted σ 2   F , includes all the non-additive genetic variance components, the majority of which is expected to be dominance variance. Dominance genetic variance (denoted as σ 2   D ) was approximated by four times the variance estimated among full-sib families when additive genetic effects are accounted for—
 
σ 2   D =4σ 2   F 
 
A relatively minor amount of σ 2   F  will be due to epistatic genetic effects, with this being included in the estimate of σ 2   D  as calculated here. Note that if there were any non-genetic effects that make members of a full-sib family more alike, this will contribute to the estimate of dominance variance.
 
     Individual heritability (h 2 ) was calculated as the ratio of additive (σ 2   A ) to phenotypic (σ 2   P ) variance among trees—
 
 h   2 =σ 2   A /σ 2   P .
 
The phenotypic variance was calculated as the sum of the additive genetic variance (σ 2   A ), variance due to families (σ 2   F ) and the residual variance (σ 2 )—
 
σ 2   P =σ 2   A +σ 2   F +σ 2  
 
     Variance due to replications was not included in the estimation of phenotypic variance because replication effects were accounted for when estimating breeding values. Standard errors of all components were estimated directly by the ASReml program. 
     Genetic correlations were estimated in multi-variate ASReml analyses using an individual tree model:
 
(Trait m1 Trait m2 Trait mn ) ijl   =mu   m. +test i.m. +(replication:test) ijm. +tree .ijllm. +residual ijlm.   III
 
where m 1 , m 2  . . . m n  denote the n traits in the multivariate analyses and tree l has a pedigree defined by its known parents and their ancestors. It was not feasible to simultaneous estimate all possible covariances using a maximum likelihood procedure, so the data were analysed in blocks of up to five traits. The additive correlations (r A ) between trait1 and trait2 represent the ratio of additive genetic covariance between the traits (cov A1A2 ) over the square root of the additive genetic variances of the same traits (σ 2   A1  and σ 2   A2 )—
 
 r   A =( cov   A1A2 )/√(σ 2   A1 σ 2   A2 )
 
Many traits with repeated measures were averaged over the years of observations for the correlation estimates. A correlation involving one trait with the average of another has the same expectation as the correlation between the first trait and any single component of the second, assuming they are genetically the same trait.
 
     
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Genetic correlations comparing year of assessment for 
               
               
                 spring budflush (e.g., BudFlush4 = assessment at 4-years). 
               
               
                 Bold numbers on horizontal are individual heritability estimates 
               
               
                 with standard errors. 
               
             
          
           
               
                   
                 Trait 
                 BudFlush2 
                 BudFlush3 
                 BudFlush4 
               
               
                   
               
               
                   
                 BudFlush2 
                   0.43  ± 0.06 
                 0.88 
                 0.81 
               
               
                   
                 BudFlush3 
                   
                   0.41  ± 0.06 
                 0.95 
               
               
                   
                 BudFlush4 
                   
                   
                   0.47  ± 0.06 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Efficacy of one- or two-year assessments of lateral flushing and 
               
               
                 sinuosity as indirect measures of double whorls, ramicorn branching, and 
               
               
                 sinuosity in a 9-year stem. The table shows individual 
               
               
                 heritability estimates and genetic correlations between indirect 
               
               
                 measures and average stem quality traits and volume. 
               
             
          
           
               
                   
                 Heritability 
                 V8B 
                 DWhorl6-9 
                 Ramicorn6-9 
                 Sinu5-9 
               
               
                   
               
             
          
           
               
                 Lateral5 
                 0.18 ± 0.03 
                 0.14 
                 0.92 
                 0.91 
                 −0.02 
               
               
                 Lateral6 
                 0.21 ± 0.03 
                 0.06 
                 0.98 
                 0.98 
                 0.01 
               
               
                 Lateral5&amp;7 
                 0.29 ± 0.04 
                 0.07 
                 0.95 
                 0.91 
                 0.04 
               
               
                 SilvFlush3-9 
                 0.37 ± 0.05 
                 0.22 
                 0.93 
                 0.93 
                 0.03 
               
               
                 Sinu5 
                 0.21 ± 0.03 
                 0.13 
                 0.09 
                 −0.02 
                 0.95 
               
               
                 Sinu6 
                 0.13 ± 0.02 
                 0.12 
                 −0.03 
                 −0.10 
                 0.99 
               
               
                 Sinu5&amp;7 
                 0.28 ± 0.04 
                 0.08 
                 0.09 
                 −0.01 
                 0.99 
               
               
                   
               
             
          
         
       
     
     While the different embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.