Acorn Ecology

Abstract

The significance of acorn production in holm oak forests can be addressed at different levels. At the individual tree level it is one of the final results of the classical trade-off between reproductive and vegetative effort (Bazzaz and Ackerly 1992; Stearns 1992). Although an iteroparous, long-living species may integrate over all its life the consequences of interannual environmental variability on individual fitness, the pattern of seed production is expected to reflect a balance between the losses of growth potential and the gains of sexual reproduction and dispersal success (Stearns 1992). Another related trade-off refers to the relationship between acorn size and seedling fate. A generally positive relationship between both parameters is expected, although interactions with other environmental factors, such as water availability, may be important (Rice et al. 1993). This individual scope can be expanded to the population level, in which fruit production is an essential component of population dynamics because both long-term persistence of populations and colonization of new locations will depend on seed availability (Fenner 1992; Crawley and Long 1995).