PREDATION OF RAMORINOA GIROLAE?S SEEDS DURING THE PRE-DISPERSAL STAGE

PAPÚ, SOFIA; GIANNONI STELLA M; CAMPOS CLAUDIA

Mendoza

Encuentro; XXXI Reunión Anual de la Sociedad de Biología de Cuyo; 2013

Sociedad de Biología de Cuyo-UNCuyo

Ramorinoa girolae is a legume endemic to the humid hills of San Juan, San Luis and La Rioja. Its fruit, woody and hardy, contains seeds that are attacked by arthropods during the pre-dispersal stage. Our objective was to analyze variability in the number of healthy (He), aborted (Ab) and attacked (At) seeds by comparing 3 sites along a humidity gradient in Ischigualasto Provincial Park: Mina de cuarzo (more), Morado (intermediate) and Tramo (less humid site). At each site, 6 trees were taken at random, separated by at least 100 m. Ten mature fruits were collected per tree during the pre-dispersal period (January 2013). In the laboratory, the number of He, At and Ab seeds were quantified. Of the total seeds for Mina de cuarzo, 51% were He, 37% At and 12% Ab. For Morado, 19% were He, 78% At and 3% Ab. For Tramo, 39% were He, 58% At and 3% Ab. Generalized linear mixed models show that differences between sites explain the proportions found. Mina de cuarzo is significantly different from the other two sites. Probably it has the most favorable conditions, and their plants produced a greater number of He seeds and adopted the abortion strategy as a way to reduce attack by arthropods.