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Genetic Variation in Basal Area Increment Phenology and its Correlation with Growth

Stand development is the result of complex interactions between genotypes and the environment
in which they grow. Research into loblolly and slash pine plantations has shown that diameter
growth rates differ between species, and among families within species when planted under
common plantation conditions (Jackson 1952, Harkin 1962, Langdon 1963, McCrady and Jokela
1996, Jayawickrama et al. 1998). The time of the year during which the cambium is active varies
with climate, species, crown class, seasonal development of leaf area in trees, and different parts
of stems and branches (Kozlowski and Pallardy 1997). Throughout the entire life span of a tree,
cambial growth is sensitive to available water in the soil (Bouriaud et al. 2005). This study
contains the results of 2-years basal area increment phenology study conducted on lands
managed by Rayonier located in Bradford County, Florida. The objectives of the study were to
assess genetic variation between species, families and clones in basal area growth increment,
phenology traits and to estimate genetic parameters.