Yb. Fu et al., Spatial patterns of tree height variations in a series of Douglas-fir progeny trials: implications for genetic testing, CAN J FORES, 29(6), 1999, pp. 714-723
Citations number
23
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
Spatial variation patterns of tree heights at ages from 6 to 12 years in a
series of Douglas-fir (Pseudotsuga menziesii (Mirb.) France) progeny trials
that were conducted on 66 test sites over southern coastal British Columbi
a were examined with conventional statistics and geostatistical techniques.
It was found that there were large variations in tree height over the year
s within and among the 66 test sites. The estimated proportions of the with
in-site variance explained by family, row, column, patchiness, and within-p
lot were on average 11, 7, 5, 12, and 47%, respectively, plus 7% due to unk
nown factors, and the applied blocking removed about 5% of the within-site
variance. Significant gradients in row and column directions were observed
in more than 44 test sites, and the estimated slopes ranged in average from
0.33 to 1.52 cm/plot, Patch sizes varied greatly over the test sites and r
anged in:average from 5.21 to 6.47 (plots), indicating that the average pat
ch size for these trials was 18 m across. Temporal variations were large fo
r family variance but not much for those variance proportions explained by
row, column, patchiness, and within-plot. More gradients and larger patch s
izes were found with older trees. Implications of these results are discuss
ed for forest genetic testing.