IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Dominant predators mediate the impact of habitat size on trophic structure in bromeliad invertebrate communities
Autor/es:
JANA S. PETERMANN; VINICIUS F. FARJALLA; MERLIJN JOCQUE; PAVEL KRATINA; ANDREW M. MACDONALD; NICHOLAS A. C. MARINO; PAULA M. DE OMENA; GUSTAVO C. O. PICCOLI; BARBARA A. RICHARDSON; MICHAEL J. RICHARDSON; GUSTAVO Q. ROMERO; VIDELA MARTIN; DIANE S. SRIVASTAVA
Revista:
ECOLOGY
Editorial:
ECOLOGICAL SOC AMER
Referencias:
Año: 2015 vol. 96 p. 428 - 439
ISSN:
0012-9658
Resumen:
 Local habitat size has been shown to influence colonization and extinction processes of speciesin patchy environments. However, species differ in body size, mobility, and trophic level, and may not respondin the same way to habitat size. Thus far, we have a limited understanding of how habitat size influences thestructure of multitrophic communities and to what extent the effects may be generalizable over a broadgeographic range. Here, we used water-filled bromeliads of different sizes as a natural model system to examinethe effects of habitat size on the trophic structure of their inhabiting invertebrate communities. We collectedcomposition and biomass data from 651 bromeliad communities from eight sites across Central and SouthAmerica differing in environmental conditions, species pools, and the presence of large-bodied odonatepredators. We found that trophic structure in the communities changed dramatically with changes in habitat(bromeliad) size. Detritivore : resource ratios showed a consistent negative relationship with habitat size acrosssites. In contrast, changes in predator : detritivore (prey) ratios depended on the presence of odonates asdominant predators in the regional pool. At sites without odonates, predator : detritivore biomass ratiosdecreased with increasing habitat size. At sites with odonates, we found odonates to be more frequently presentin large than in small bromeliads, and predator : detritivore biomass ratios increased with increasing habitatsize to the point where some trophic pyramids became inverted. Our results show that the distribution ofbiomass  amongst  food-web  levels  depends  strongly  on  habitat  size,  largely  irrespective  of  geographicdifferences in environmental conditions or detritivore species compositions. However, the presence of large-bodied predators in the regional species pool may fundamentally alter this relationship between habitat sizeand trophic structure. We conclude that taking into account the response and multitrophic effects of dominant,mobile species may be critical when predicting changes in community structure along a habitat-size gradient.