Inter- and Intraspecific Variation in Fruit Traits in Co-Occurring Vertebrate-Dispersed Plants

Abstract

A quantitative analysis of the patterns of intra- and interspecific variance of fleshy fruit traits (length, width, pulp mass, seed mass, percent pulp mass) in eight species of southeastern Spanish vertebrate-dispersed plants, Berberis hispanica, Crataegus monogyna, Daphne laureola, Hedera helix, Juniperus communis, Juniperus phoenicea, Juniperus sabina, and Rosa canina, shows a statistically significant individual variability in the five fruit traits considered. Individual variability tended to be largest for pulp mass and seed mass (coefficient of variation of individual means between 20% and 30%) and smallest for fruit width and length and for proportion of pulp (CV of 5%-12%). Most variance in fruit traits (67%-88%) was accounted for by taxonomic affiliation, while the remainder of the variance was partitioned in roughly similar proportions among and within plants of individual species. There were some differences between fruit traits in the relative proportion of variance contributed by within and among individual variation, but all fruits traits in all species consistently exhibited a remarkably high proportion of within-individual variance, roughly comparable to the variance among individuals. The potential ecological and evolutionary implications of observed patterns of fruit variability are discussed in relation to the foraging behavior of seed-dispersing frugivores.