Workshop on forest fragmentation in South America. Understanding biodiversity loss. Bariloche, Argentina, 26 al 30 de Junio de 2006. Authors: Aguilar R. Ashworth L., Galetto L. & Aizen M.A. Título: Pant reproductive susceptibility to habitat fragmentation .

LEONARDO GALETTO,

Bariloche

Taller; Workshop on forest fragmentation in South America. Understanding biodiversity loss. Bariloche, Argentina, 26 al 30 de Junio de 2006. Authors: Aguilar R. Ashworth L., Galetto L. & Aizen M.A. Título: "Pant reproductive susceptibility to habitat fragmentatio; 2006

Workshop on forest fragmentation in South America. Understanding biodiversity loss. Bariloche, Argentina, 26 al 30 de Junio de 2006. Authors: Aguilar R. Ashworth L., Galetto L. & Aizen M.A. Título: "Pant reproductive susceptibility to habitat fragmentatio

PLANT REPRODUCTIVE SUSCEPTIBILITY TO HABITAT FRAGMENTATION Ramiro Aguilar1, Lorena Ashworth1, Leonardo Galetto1 & Marcelo Adrián Aizen2 1 Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba – CONICET, CC 495, (5000) Córdoba, Argentina. Tel.: 0351 4330421. E-mail: leo@imbiv.unc.edu.ar, website: http://imbiv.unc.edu.ar 2 Laboratorio Ecotono, Universidad Nacional del Comahue, Quintral 1250 (8400), San Carlos de Bariloche, Río Negro, Argentina. Abstract A clear and well-written abstract of 400 words maximum, including the key references. Throughout the last two decades fragmentation studies on plant populations have mainly focused on demographic processes, with particular emphasis in evaluating the effects of fragmentation on plant fecundity (Aizen et al. 2002, Ghazoul 2005). Animal-mediated pollination is a key process for the sexual reproduction of most extant flowering plants, thus the pollinator fauna and pollination process have equally been studied in relation to habitat fragmentation. By means of a meta-analysis we quantitatively reviewed the results from independent fragmentation studies, with the aim of testing whether pollination and reproduction of plant species may be differentially susceptible to habitat fragmentation depending on certain reproductive traits that typify the relationship with and the degree of dependence on their pollinators. We found an overall large and negative effect of fragmentation on pollination and on plant reproduction. The compatibility system of plants, which reflects the degree of dependence on pollinator mutualism, was the only reproductive trait that explained the differences among the species’ effect sizes. In agreement with our stated hypothesis, self-incompatible plants showed a strong negative effect of habitat fragmentation on reproduction, whereas self-compatible plants were not significantly affected. Contrary with the expectations based on the classical theoretical concepts, which hold that reproduction of specialist species should be more negatively affected by fragmentation than generalist species, the effect sizes of plants with different degree of pollination specialization did not differ significantly between them. We propose a possible explanation for this unexpected response pattern based on Ashworth et al. (2004). Furthermore, a highly significant correlation between the effect sizes of fragmentation on pollination and reproductive success suggests that the most proximate cause of reproductive impairment in fragmented habitats may be pollination limitation. We discuss the conservation implications of these findings and give some suggestions for future research on this area.