Annual Variability in Cone and Seed Yields Across Seed Stands of Taurus Cedar (Cedrus libani) and Its Impact on Gene Diversity of Seed Crops

Variation and comparison of annual cone and seed productions, and seed characteristics (number and percentage of filled seeds per cone) were examined for three consecutive years at three seed stand populations of Taurus cedar (Cedrus libani A. Rich.) with distinct structural characteristics. Fertility variation in cone and seed production was analyzed and discussed to inform for management practices of seed stands and for other silvicultural interventions. The analysis of variance showed the significant differences among populations and years, as well as among trees within a population and a year for both cone and seed production and seed characteristics. Population x year interactions were also significant (p<0.05), highlighting the importance of cone collecting stand and seed harvesting year. The parental balance curves showed that the cone production was much closer to equal contribution to the gamete gene pool than the production of filled seeds across years, suggesting that the number of cones is a better indicator of overall seed production. Fertility variation () in cones and filled seeds (1.10≤≤ 1.71 except 2.38 in a population and year) showed small deviation among seed stands and among years within a seed stand. Gene diversity of seed crops has increased through clustering populations and pooling years reaching values of 0.998 and 0.997, respectively.