Crop size influences pre-dispersal seed predation in the Brazilian Cerrado

Abstract

Many pre-dispersal seed predators are specialized insects that rely on seeds for larval development. Th ese insects may respond to the amount of seeds produced by a plant (i.e. crop size), increasing the proportion of seeds damaged with increases in seed numbers. Large seeds have more resources and spend more time in plants to complete their development and are probably more prone to be preyed on by those insects than small seeds. Here I tested how crop size and seed mass infl uence pre-dispersal seed predation in plants from the Cerrado savannas of Brazil. I related plant crop size to pre-dispersal seed predation for Xylopia aromatica and Erythroxylum pelleterianum. A literature review was performed to test if seed mass may explain among-species diff erences in pre-dispersal seed predation. Pre-dispersal losses increased proportionally to crop size in the two species investigated, but some species show positive or no density-dependent seed predation in literature, indicating that seed losses are not a simple function of crop sizes. Seed mass did not explain pre-dispersal seed loss diff erences among 14 species with data available. Pre-dispersal losses are often small and probably less important than seed dispersal and establishment limitation for plant recruitment in Cerrado savannas.

Individual crop size increases predispersal predation by beetles in a tropical palm

“…Predispersal seed predation is one of the main causes of seed mortality in plant populations (Janzen, 1969(Janzen, , 1970(Janzen, , 1971aZhang et al, 1997;Andersen, 1998;Ramírez and Traveset, 2010), increasing seed limitation and contributing to decrease plant recruitment (Louda, 1982;Kolb et al, 2007). Crop size (the number of seeds produced by an individual plant) and intra-and interpopulational variations may explain some changes in predispersal seed predation (Janzen, 1971a;Traveset, 1995;Crawley, 2000;Xiao et al, 2015;Christianini, 2017).…”