ALLY, DILARA* AND KERMIT RITLAND. Dept. of Forest Sciences, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada. - Marker-estimated heritabilities and spatial patterns of relatedness in a natural forest stand of mountain hemlock (Tsuga mertensiana).
Knowledge of both the distribution and level of heritable variation
are important in understanding historical patterns of natural
selection and the impact of disturbance on these patterns. In
long-lived species like trees, traditional techniques for measuring
additive genetic variation using controlled breeding experiments are
made difficult because of the long generation time and thus are of
limited use. Furthermore, classical estimates inadequately account
for shared environments, inbreeding and other factors which occur in
natural populations. The two major goals of our study were 1) to
determine the magnitude of field heritability in a mountain hemlock
stand for six quantitative traits, and 2) examine the impact of
disturbance on local patterns of relatedness in this stand. By
regressing quantitative trait similarity on microsatellite-estimated
relatedness, we evaluate the level of heritable variation. These
estimates of pairwise relatedness are also used to investigate a
process underlying the generation of local population structure,
namely local dispersal.
Key words: evolution ,conifer,dispersal,relatedness