REPRODUCTION OF SALAL (GAULTHERIA-SHALLON) UNDER FOREST CANOPY

Sexual reproduction occurred only at ≤33% closure; vegetative reproduction occurred under sparse and dense closure. Crown closure influenced sexual reproduction primarily through interception of radiation and associated reductions in salal vigour. Irradiance had a greater influence on the mode of reproduction than did shoot density, and allocation of total reproductive effort (sexual plus vegetative) was contrary to optimality models, but consistent with resource limitation. No shoot 5 yr old flowered; shared costs of flowering indicated physiological intergration among salal shoots. Vegetative reproduction was negatively associated with age, and 85% of the space occupied after 9 yr of growth was occupied during the first 3 yr. Under canopy the spatial pattern of salal shoots was better adapted to maintain plant persistence than to colonize new areas. -from Author