Whitebark pine (Pinus albicaulis Engelm.) seed production in natural stands

The mature cones of whitebark pine from two high-elevation natural stands in central Idaho and western Nevada were analyzed in 2004 to determine the seed numbers and quality. It has the typical 2-year pine reproductive cycle. Cones are indehiscent and deciduous at maturity and the seeds lack seed wings. Cones averaged 62 scales, 75% of which were fertile with a seed potential of 96 seeds per cone. Total seeds per cone averaged 66 of which 46 were filled. Other potentially filled seeds were lost for different causes including abortion before pollination, abortion soon after pollination due to a lack of pollination or self-pollination, abortion about the time of fertilization due to self-fertilization, abortion during early and late-embryo development, and damage by insects or disease during development. About 70% of total seeds were filled and likely viable, which is high for conifers in natural stands especially at high elevations. (C) 2007 Elsevier B.V. All rights reserved.