Provenance Variation in Podocarpus totara
- Forest Research Institute Rotorua, Private Bag 3020, Rotorua, New Zealand
Variation in seedling growth and form between provenances of Podocarpus totara from 42 sites throughout New Zealand was investigated. Seedlings were grown for three years under uniform nursery conditions. There were significant differences between provenances in height growth in the first three years after sowing. Early growth was highly correlated with germination rate after sowing. In the third year, growth followed a different pattern and was negatively correlated with provenance latitude, i.e., provenances from southern latitudes grew more slowly than those from further north. This suggests that genetic factors correlated with mean summer temperature of the locality of seed source were beginning to predominate. Stem form and branch length also varied between provenances, but foliage colour and leaf size did not. Neither stem form nor branch length were related to any provenance site variable. Since provenance variation is appreciable, it is recommended that P. totara plantings for ecological purposes should be of seedlings raised from locally collected seed. However, for growing P. totara in plantations to produce special-purpose high value timber, considerable scope exists for an in-depth breeding study that will eventually lead to producing planting stock with both superior height growth and good tree form.