Spatio-temporal Genetic Structure of a Tropical Bee Species Suggests High Dispersal Over a Fragmented Landscape

• Type of Material: Article
• Authors: Sevan S. Suni, University of Arizona; Judith L. Bronstein, University of Arizona; Berry J Brosi, Emory University
• Language: English
• Date: 2014-03-01
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 The Association for Tropical Biology and Conservation.
• Final Published Version (URL): http://dx.doi.org/10.1111/btp.12084
• Title of Journal or Parent Work: Biotropica
• ISSN: 0006-3606
• Volume: 46
• Issue: 2
• Start Page: 202
• End Page: 209
• Grant/Funding Information: SSS was supported by the Center for Insect Science at the University of Arizona (NIH grant 5K12 GM000708).
• Keywords: Science & Technology; DIFFERENTIATION; Environmental Sciences & Ecology; POPULATIONS; POLLINATORS; euglossine; APIDAE; dispersal; RAIN-FOREST; genetic differentiation; orchid bee; MICROSATELLITE LOCI; Life Sciences & Biomedicine; landscape genetics; HYMENOPTERA; Ecology; BUMBLE BEES; DECLINE; EUGLOSSINE BEES; fragmentation
• Research Categories: Biology, Entomology; Environmental Sciences; Biology, Ecology

Abstract

Habitat destruction threatens biodiversity by reducing the amount of available resources and connectivity among geographic areas. For organisms living in fragmented habitats, population persistence may depend on dispersal, which maintains gene flow among fragments and can prevent inbreeding within them. It is centrally important to understand patterns of dispersal for bees living in fragmented areas given the importance of pollination systems and recently documented declines in bee populations. We used population and landscape genetic techniques to characterize patterns of dispersal over a large fragmented area in southern Costa Rica for the orchid bee species Euglossa championi. First, we estimated levels of genetic differentiation among forest fragments as φ{symbol}PT, an analog to the traditional summary statistic FST, as well as two statistics that may more adequately represent levels of differentiation, G'ST and Dest. Second, we used a Bayesian approach to determine the number and composition of genetic groups in our sample. Third we investigated how genetic differentiation changes with distance. Fourth, we determined the extent to which deforested areas restrict dispersal. Finally, we estimated the extent to which there were temporal differences in allele frequencies within the same forest fragments. Within years we found low levels of differentiation even over 80 km, and no effect of land use type on level of genetic differentiation. However, we found significant genetic differentiation between years. Taken together our results suggest that there are high levels of gene flow over this geographic area, and that individuals show low site fidelity over time.