Two New Zealand-based common garden experiments of the range-wide 'Kuser' clonal collection of Sequoia sempervirens reveal patterns of provenance variation in growth and wood properties

Sequoia sempervirens (Coast redwood (Lamb. ex D. Don) Endl.) plantings in New Zealand are increasing due to favourable growth rates. There is, however, very limited information on S. sempervirens genetics on which to build breeding and deployment decisions. In this study we present results from the assessment of growth, wood density, heartwood area, and epicormic shoots in two replicated clonal provenance trials of 170 S. sempervirens clones at two sites. Across-site genetic correlations among provenance for traits were high, 0.9 or above, with the exception of 0.7 for epicormic shoots. Mediumto-high genetic control was expressed for all growth and wood property traits. Broad-sense heritabilities for the two sites assessed were: diameter at breast height (1.4 m) (0.35 and 0.52), wood density (0.52 and 0.30), and percentage heartwood (0.40 and 0.50). Epicormic shoots were under low genetic control (0.11 and 0.27) and may be more influenced by the environment. Genetic correlations between traits showed that growth rate was negatively correlated with wood density (-0.52 to -0.58). Faster growth was also correlated with more epicormic shoots (0.36-0.44). We found no strong trends between growth performance, provenance location, or provenance site characteristics of the material tested. In contrast to earlier research in the United States of America, this study found a high clonal repeatability for the above traits and it demonstrated a low genotype 9 environment interaction. This study provides important and new insights in the genetic variability of S. sempervirens provenances.