The relationships between fruit ripeness, wasp seed predation, and avian fruit removal in pistacia palaestina

Substantial variation in fruit removal between individual Pistacia palaestina plants was observed in northern Israel. To elucidate the causes of this variation, I examined several proximal sources of between-individual variation in fruit removal and dispersal efficiency. Crop size, tree height, and diameter explained some between- individual variation in fruit removal. Dispersal efficiency was mainly influenced by the proportion of the unripe fruits (including aborted and parthenocarpic fruits). Comparison of several reproductive parameters of P. palaestina with another Pistacia species (P. terebinthus) in Spain, revealed that P. palaestina produces larger fruit crop, faces higher seed prédation by infesting wasps, and has lower proportions of parthenocarpy and fruit abortion than Pistacia terebinthus. Fruit removal and dispersal efficiency of the former is much higher than the latter.