Pre-dispersal seed loss of Ramorinoa girolae (Fabaceae) in Ischigualasto Provincial Park (San Juan, Argentina)

PAPÚ, SOFÍA; LAGOS SILNIK, SUSANA; CAMPOS, CLAUDIA

BOLETíN DE LA SOCIEDAD ARGENTINA DE BOTáNICA

SOCIEDAD ARGENTINA DE BOTÁNICA

Lugar: Córdoba; Año: 2015 vol. 50 p. 585 - 594

0373-580X

Summary: Ramorinoa girolae Speg. is a ?vulnerable? tree endemic to Argentina. During the pre-dispersalstage, the seeds are predated by Anypsipyla univitella. The objectives of this study were to describe somereproductive parameters (size and number of fruits and seeds) of R. girolae, to quantify pre-dispersalseed loss by abortion and predation, and to test the effect on pre-dispersal seed predation of fruitproduction (per tree, of co-specific neighbors, and the sum of both), size of fruits, number of seeds perfruit, and number of predators per fruit. As seeds can be partially consumed by the predator, the viabilityof partially damaged seeds was assessed as well. At Ischigualasto Park, we sampled 17 adult treesfrom 3 stands spaced 4 km apart. For each focal tree, we quantified the number of co-specific neighborsand their fruits. We collected ten fruits from canopies and recorded their length and the number andstates of seeds (intact, predated, and aborted). Generalized Linear Mixed Models were fitted to evaluateexplanatory variables affecting the proportion of pre-dispersal predated seeds. R. girolae suffers greatloss of seeds during the pre-dispersal stage, mainly by seed predation (58% of seeds). The proportion ofpredated seeds was most important relative to the number of predators, the number of seeds per fruit, andthe size of fruits. Fruits containing more predators, more seeds, and smaller fruits had higher proportionsof predated seeds. Seed abortion would not represent an important factor of seed loss (6% of seeds).