On Ovule Production in Environments where Pollinator or Resource Availability is Unpredictable

Abstract

I develop two optimal-allocation models to investigate bet-hedging on ovule production as an evolutionary strategy in environments where either pollinator availability or resource availability is unpredictable. In both models, a plant allocates the resources available in the flower stage to its attractive structures, ovule production, and/or reserves in the fruit stage. The pollinator availability for the year (in the first model) or the resource availability of the fruit stage (in the second model) is unpredictable. I show that large variability in pollinator or resource availability does not always select for an increase in the number of ovules produced by the plant. Rather, the plant decreases its ovule number in habitats where pollinator or resources availability is more variable. In the first model, this occurs if the expected pollinator availability is large, the resource availability is small, the recovery rate of reserved resources is small, or the prior selfing rate is large with a large degree of inbreeding depression. In the second model, it occurs if the pollinator availability is small or the expected resource availability is large. Thus, the bet-hedging hypothesis within the context of variation in ovule/flower number does not always work for ovule production in environments where pollinator or resource availability is unpredictable.