What are the relative costs, limits and correlates of increased degree of serotiny?

There is variability in the period that serotinous species retain seeds in protective closed cones and in the sizes of the cones. Seed predation and i nter-fire recruitment have been suggested to be reasons for this variabilit y. I argue against these two reasons. Variation in annual rates of increase in fecundity and in numbers of flowering episodes before fire should be co rrelated with the degree of serotiny. These two attributes are a consequenc e of cone size, plant architecture and degree of serotiny.