18 research outputs found
Modularity, pollination systems, and interaction turnover in plant-pollinator networks across space
No full textMade available in DSpace on 2018-12-11T17:37:09Z (GMT). No. of bitstreams: 0
Previous issue date: 2016-05-01Mutualistic interaction networks have been shown to be structurally conserved over space and time while pairwise interactions show high variability. In such networks, modularity is the division of species into compartments, or modules, where species within modules share more interactions with each other than they do with species from other modules. Such a modular structure is common in mutualistic networks and several evolutionary and ecological mechanisms have been proposed as underlying drivers. One prominent explanation is the existence of pollination syndromes where fl owers tend to attract certain pollinators as determined by a set of traits. We investigate the modularity of seven community level plant-pollinator networks sampled in rupestrian grasslands, or campos rupestres, in SE Brazil. Defi ning pollination systems as corresponding groups of fl ower syndromes and pollinator functional groups, we test the two hypotheses that (1) interacting species from the same pollination system are more often assigned to the same module than interacting species from different pollination systems and; that (2) interactions between species from the same pollination system are more consistent across space than interactions between species from different pollination systems. Specifi cally we ask (1) whether networks are consistently modular across space; (2) whether interactions among species of the same pollination system occur more often inside modules, compared to interactions among species of different pollination systems, and fi nally; (3) whether the spatial variation in interaction identity, i.e., spatial interaction rewiring, is affected by trait complementarity among species as indicated by pollination systems. We confi rm that networks are consistently modular across space and that interactions within pollination systems principally occur inside modules. Despite a strong tendency, we did not fi nd a signifi cant effect of pollination systems on the spatial consistency of pairwise interactions. These results indicate that the spatial rewiring of interactions could be constrained by pollination systems, resulting in conserved network structures in spite of high variation in pairwise interactions. Our fi ndings suggest a relevant role of pollination systems in structuring plant-pollinator networks and we argue that structural patterns at the sub-network level can help us to fully understand how and why interactions vary across space and time.Departamento de Botânica Laboratório de Fenologia Plant Phenology and Seed Dispersal Group Instituto de Biociências Universidade Estadual Paulista (UNESP), Avenida 24-A n 1515Center for Macroecology Evolution and Climate Natural History Museum of Denmark University of Copenhagen, Universitetsparken 15EEA (Estación Experimental Agropecuaria) Balcarce INTA (Instituto Nacional de Tecnología Agropecuaria)Departamento de Botânica Laboratório de Fenologia Plant Phenology and Seed Dispersal Group Instituto de Biociências Universidade Estadual Paulista (UNESP), Avenida 24-A n 151
Introducing the biogeographic species pool
No full textThe species pool concept has played a central role in the development of ecological theory for at least 60 yr. Surprisingly, there is little consensus as to how one should define the species pool, and consequently, no systematic approach exists. Because the definition of the species pool is essential to infer the processes that shape ecological communities, there is a strong incentive to develop an ecologically realistic definition of the species pool based on repeatable and transparent analytical approaches. Recently, several methodological tools have become available to summarize repeated patterns in the geographic distribution of species, phylogenetic clades and taxonomically broad lineages. Here, we present three analytical approaches that can be used to define what we term 'the biogeographic species pool': distance-based clustering analysis, network modularity analysis, and assemblage dispersion fields. The biogeographic species pool defines the pool of potential community members in a broad sense and represents a first step towards a standardized definition of the species pool for the purpose of comparative ecological, evolutionary and biogeographic studies. © 2013 The Authors
Interactiondata_all_Brazil
No full textEdgelist data file with interactions from all seven Brazilian sites
