Seed predation of Copaifera langsdorffii (Fabaceae): a tropical tree with supra‐annual fruiting

Abstract

Seed predation is an important ecological and evolutionary force that directly affects the distribution of plant species. Copaifera langsdorffii is a tropical tree species with supraannual fruiting, which has its seeds predated by a specialist endogenous insect (Rynochenus brevicollis: Curculionidae) in the Brazilian savanna. Three hypotheses were addressed: (i) the predator satiation hypothesis, (ii) the resource concentration hypothesis and (iii) the larger seed predation hypothesis. A total of 112 individual C. langsdorffii were monitored monthly from January to August during four consecutive years (from 2008 to 2011) to determine the presence of fruits on each plant. All trees produced fruits in the year 2008, whereas none of them produced flowers or fruits in 2009 or 2010. Moreover, only 65 individuals (58%) marked in 2008 produced fruits in 2011. The number of fruits per plant was approximately 21% greater in 2008 than in 2011, while the percentage of seed predation was 76% greater in 2011, thereby supporting the predator satiation hypothesis. The percentage of seeds predated was not affected by the number of fruits per plant. Therefore, our data did not support the resource concentration hypothesis. Plants producing large seeds experienced more seed predation by R. brevicollis, supporting the larger seed predation hypothesis. In addition, we also observed a positive relationship between seed volume and adult R. brevicollis weight. This study demonstrates the importance of supra-annual fruiting for increasing survivorship of C. langsdorffii seeds both at the individual and the population level, and suggests that seed predators select plants producing large seeds as a way of increasing the number of offspring.

Intraspecific variation in seed size and light intensity affect seed germination and initial seedling growth of a tropical shrub

“…The region has a semi-arid climate with well-defined dry and wet seasons. The average annual temperature is 23˚C and rainfall is about 1000 mm/ year (Souza & Fagundes 2017). A total of 20 well-formed seeds were haphazardly collected from each individual plant, packed in individual paper bags and weighed with an analytical scale to determine the biomass of each seed.…”

“…age, photoblastism, dormancy) attributes of seeds can interact with ecological variables (e.g. light, temperature, moisture, soil quality, seed predation) to determine the local abundance of plant species (Rojas-Aréchiga et al 2013;Ribeiro & Borghetti 2014;Souza & Fagundes 2017). Th us, fi nding a predictable relationship between plant life history and environmental variables will help determine the ability of plants to become established and elucidate traits that allow species to become dominant in specifi c habitats (Murray et al 2005;Ferreras et al 2015;Jelbert et al 2015).…”

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

“…There was also substantial within-species variation among years (e.g. 8.2 % and 15.9 % of seed predation in two years for Copaifera langsdorffii) (Souza & Fagundes 2017) and sites (0 % and 51.3 % seed predation in two different sites for Callisthene major) (Custódio et al 2014) (Tab. 1).…”

“…1). For another species (Copaifera langsdorffii) increments in crop sizes between years were not followed by changes in seed losses, suggesting predator satiation (Souza & Fagundes 2017). Enhancement of seeds losses with increasing seed density may constrain the evolution of large crop sizes.…”

Does inter-plant variation in sprouting time affect the growth/reproduction trade-off and herbivory in a tropical tree species?

“…Furthermore, inter-plant variation in phenological events can be caused by genetic diff erences in age, size, and reproductive eff ort in the previous years, as well as interactions with higher trophic levels (Schemske et al 1978;Souza & Fagundes 2016).…”