OOS 18
What Is The Fate Of a Forest Without Vertebrate Frugivores? Merging Case Studies With Theory

Wednesday, August 7, 2013: 8:00 AM-11:30 AM
101F, Minneapolis Convention Center
Organizer:
Haldre S. Rogers
Co-organizer:
Clare E. Aslan
Moderator:
Joshua J. Tewksbury
Frugivorous vertebrates are disproportionately prone to extinction due to wide range requirements and high hunting pressures (Peres 2001). In a range of habitats, researchers have examined “empty forests” (Redford 1992) resulting from such losses and have detected impacts (McConkey et al 2012). While a growing number of case studies have examined loss of vertebrate seed dispersers (e.g., Meehan et al. 2002, Cordeiro and Howe 2003), the studies have focused primarily on the species-specific effects of their loss. We lack a comprehensive understanding of the importance of vertebrates to forest communities, which is critically important for predicting the impact of vertebrate loss on ecosystems. Several species coexistence theories rely on dispersal to maintain species diversity, but there has been little application of this theory to predict the effects of disperser loss on species diversity. Fundamental community changes may result from seed disperser loss including: a) an increase in wind-dispersed or invasive species (Brodie and Aslan 2011); b) broad failure of gap colonization, accelerating forest fragmentation; c) extinction of large-seeded plants (McConkey and Drake 2002); d) stalled regeneration of degraded habitat (Kettle 2012); and e) extinction of species with strong negative density-dependent mortality. These changes would result from altered abundance and/or spatial pattern of tree species, a pattern that has appeared in many case studies (McConkey et al 2012). Yet, in practice, it is often assumed that plant restoration in degraded habitats will generate vertebrate return, and that deliberate restoration of vertebrate populations is unnecessary (Brodie and Aslan 2011). To explore the community-level implications of disperser loss, it is necessary to move beyond case study to synthesis, and to unite theoreticians with empiricists. Can we identify overarching patterns in forest communities following seed disperser loss? Do communities universally change character or enter alternative stable states (Brodie and Aslan 2011), or do they largely retain their original characteristics? We propose to gather speakers that have explored seed dispersal disruption through case study and theoreticians that have considered the effects of seed dispersal beyond individual communities. All presentations will describe results of current seed dispersal disruption research, and authors will be encouraged to present their results in the context of community-level impacts. It is our belief that the time is ripe for a community-scale theory of seed disperser loss and its impact on forests. Therefore, the final talk of the session will focus on that challenge and will invite ideas for a synthesis paper.
8:20 AM
 Size matters: Meta-analysis of the effects of human disturbance on seed dispersal by animals
Matthias Schleuning, Biodiversity and Climate Research Centre (BiK-F); Julia S. Markl, Biodiversity and Climate Research Centre (BiK-F); Pierre Michel Forget, Museum National d'Histoire Naturelle; Pedro Jordano, Estación Biológica de Doñana, CSIC; Joanna E. Lambert, The University of Texas at San Antonio; Anna Traveset, IMEDEA (CSIC-UIB); S. Joseph Wright, Smithsonian Tropical Research Institute; Katrin Böhning-Gaese, Biodiversity and Climate Research Centre (BiK-F)
8:40 AM
 Does primate disappearnace influcence the advanced regeneration assemblage in rainforest fragments
Kathryn E. Stoner, Texas A&M University - Kingsville; Oscar M. Chavez, a Pontifícia Universidade Católica do Rio Grande do Sul; Victor Arroyo-Rodriguez, Universidad Nacional Autonoma de Mexico; Miguel Martinez-Ramos, Universidad Nacional Autonoma de Mexico
9:20 AM
 An experimental test of gibbon and bird seed dispersal patterns
Jackson L. Frechette, University of Florida; Douglas J. Levey, National Science Foundation
9:40 AM
9:50 AM
 The study of spatiotemporal ecological point processes
Matteo Detto, Smithsonian Tropical Research Institute; Helene C. Muller-Landau, Smithsonian Tropical Research Institution
10:10 AM
 Frugivore communities and seed rain in regenerating pastures in Costa Rica
J. Leighton Reid, University of California Santa Cruz; Chase D. Mendenhall, Stanford University; J. Abel Rosales, Organization for Tropical Studies; Román Gómez, Organization for Tropical Studies; Rakan A. Zahawi, Organization for Tropical Studies; Karen D. Holl, University of California Santa Cruz
10:30 AM
 How might Pacific Island forests be affected by the loss of native seed dispersers and their replacement by novel species?
Donald R. Drake, University of Hawai'i at Manoa; Kim R. McConkey, A. V. Rama Rao Research Foundation
10:50 AM
 Predators and dispersers: Rodents leave viable seed fragments of a threatened Atacama Desert plant in suitable sites for recruitment
Andrea P. Loayza, Universidad de La Serena; Danny E. Carvajal, Universidad de La Serena; Patricio A. García-Guzman, Universidad de La Serena; Julio R. Gutiérrez, Universidad de La Serena; Francisco A. Squeo, Universidad de La Serena
11:10 AM
 Case study: The impact of complete frugivore loss on the island of Guam
Haldre S. Rogers, Rice University; Janneke HilleRisLambers, University of Washington; Joshua J. Tewksbury, WWF International