Ecological and genetic effects on the mating system of a long-lived perennial, Kalmia latifolia

Mating systems are known to evolve. Variation in mating systems has been found at different levels such as within species, within populations, and within families. I have found that an individual's mating system is also free to vary to some degree. The proportion of selfed vs. outcrossed seeds a plant produces is not entirely genetically fixed. Ecological factors, in addition to genetic, can influence an individual's production of self-fertilized vs. outcrossed seeds, a plant's mating system.; I present spatial and temporal variation in outcrossing rates and the effects of pollen limitation and inbreeding depression on the mating system of Kalmia latifolia, a long-lived evergreen shrub. I also report a test for the adaptiveness of selfing by quantifying the prevalent mode of self-fertilization, as influenced by pollinator behavior.; I propose two novel ecological factors that can affect mating systems. Time of pollination and disease damage influence selfed seed production at a different rate than outcrossed seed production. These data suggest that levels of resource availability within a plant influence the expression of its mating system. Since a plant's effective mating system can be sensitive to the conditions under which it is measured, estimates of selfing rates may be more meaningful if the ecological context of the measurement is understood.