The fitness of reproductive-cycle plasticity in yellow-cedar (Chamaecyparis nootkatensis)

The development of an abbreviated reproductive cycle in yellow-cedar is considered to be a classical form of phenotypic plasticity that occurs in response to a favourable environmental stimulus. The ability of genotypes to produce a diversity of reactions/forms in response to various environmental conditions secures its survival ; however, survival alone does not ensure the genotypes' reproductive success. I analyzed the fitness of the observed reproductive-cycle plasticity in seed germination of yellow-cedar produced under a normal 3-year-reproductive cycle and compared it with that produced under an abbreviated 2-year-reproductive cycle. The germination of viable seed produced from abbreviated reproductive cycle was higher than that from high-elevation seedlots (i.e., control), indicating that there is a potentially greater cost for fitness at high-elevations due to the dependence on the presence of a favourable environment during the 2-year-period required for a seed to develop.