Effects of Forest Fragmentation on Pollinator Activity and Consequences for Plant Reproductive Success and Mating Patterns in Bat-pollinated Bombacaceous Trees1

Abstract

Forest fragmentation and the resulting spatial isolation of tree species can modifj the activity of pollinators and may have important implications for the reproductive success and mating systems of the plants they pollinate. The objectives of this study were to (1) evaluate the effect of forest fragmentation on pollinator activity in bat-pollinated bombacaceous trees and (2) determine the effects of forest fragmentation on reproductive success and mating systems of bombacaceous trees. We studied these parameters in three bombacaceous tree species in tropical seasonal forest of Chamela, Jalisco, Mexico, and Osa and Guanacaste, Costa Rica. For Ceiba aesrulifolia, more visits were observed in fragments by both Glossopbaga soricina and Leptonycteris rurasoae. For Ceiba grandzfira, Musonyctmis barrijoni visited flowers exclusively in forest and G. soricina visited more flowers in forest than in fragments; no difference was shown by L. rurasoae. For Ceiba pentandra in Chamela, no differences were found in visitation by G. soricina between forest and fragments; L. curasoae visited significantly more flowers in forest. Ceiba pentandra received more visits by Pbyllostomus discolor than G. soricina in Guanacaste, whereas no bat visitors were observed in Osa. Total mean flower production was greater in fragments than forest for C. aesculifolia, whereas no difference was observed for C. grandzjora. Fruit set was greater in forest than in fragments for C. grandzfira, whereas no difference was observed for C. aesrulzfilia.Outcrossing rates were high for C. aesrulzjlia and C. grandzfira in Chamela, and for C. pentandra in Guanacaste, independent of tree habitat, while C. pentandra in Osa showed a mixed-mating system. The effects of forest fragmentation on bat pollinators, plant reproductive success, and mating patterns varied depending upon the bombacaceous species. This variability was associated with the effects that forest fragmentation may have on differences in v) '0 rn 0 5 v) 0 flowering patterns, bat foraging behavior, and plant self-incompatibility systems.rn RESUMEN La fragmentaci6n de bosques y el aislamiento spacial, product0 de este fenomeno, pueden modificar la actividad de 10s polinizadores y pueden tener implicaciones importantes sobre el txito reproductivo y 10s sistemas de apareamiento de las plantas que polinizan. Los objetivos de este estudio consisten en: (1) evaluar 10s efectos de la fragmentaci6n de bosque sobre la actividad de 10s polinizadores de drboles de Bombacaceas, y (2) determinar 10s efectos de la fragmen-taci6n sobre el txito reproductivo y el sistema de apareamiento de irboles de Bombacaceas. Evaluamos estos parhetros en 3 especies de irboles de esta familia en bosques estacionales en Jalisco, Mtxico y Guanacaste y Osa, Costa Ria. Las flores de Ceiba aesculzjdia fueron mas visitadas en fragmentos por Glossopbaga soricina y Leptonycteris rurasoae. En Ceiba grandzjlora, Musonycteris barrijoni visit6 flores exclusivamente en el bosque y G. soricina visit6 mas flores en el bosque que en 10s fragmen...

Reproductive biology of Spondias tuberosa Arruda (Anacardiaceae), an endemic fructiferous species of the caatinga (dry forest), under different management conditions in northeastern Brazil

“…Most studies indicate that habitat transformation has negative consequences for reproductive success in both humid (Ghazoul and McLeish, 2001;Murren, 2002) and arid (Aizen and Feinzinger, 1994a;Fuchs et al, 2003;Quesada et al, 2004) ecosystems. On the other hand, some species apparently present positive changes in their reproductive strategies after habitat alteration, such as enhanced flower production in both types of environments (Murren, 2002;Fuchs et al, 2003;Quesada et al, 2004).…”

Spatial Pattern and Fine-Scale Genetic Structure Indicating Recent Colonization of the Palm Euterpe edulis in a Brazilian Atlantic Forest Fragment

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Reproductive biology of two tree species of Leguminosae in a Montane Rain Forest in southeastern Brazil

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