Frugivore species maintain their structural role in the trophic and spatial networks of seed dispersal interactions

1. Trophic relationships have inherent spatial dimensions associated with the sites where species interactions, or their delayed effects, occur. Trophic networks among interacting species may thus be coupled with spatial networks linking species and habitats whereby animals connect patches across the landscape thanks to their high mobility. This trophic and spatial duality is especially inherent in processes like seed dispersal by animals, where frugivores consume fruit species and deposit seeds across habitats. 2. We analysed the frugivore–plant interactions and seed deposition patterns of a diverse assemblage of frugivores in a heterogeneous landscape in order to determine whether the roles of frugivores in network topology are correlated across trophic and spatial networks of seed dispersal. 3. We recorded fruit consumption and seed deposition by birds and mammals during 2 years in the Cantabrian Range (N Spain). We then constructed two networks of trophic (i.e. frugivore–plant) and spatial (i.e. frugivore–seed deposition habitat) interactions and estimated the contributions of each frugivore species to the network structure in terms of nestedness, modularity and complementary specialization. We tested whether the structural role of frugivore species was correlated across the trophic and spatial networks, and evaluated the influence of each frugivore abundance and body mass in that relationship. 4. Both the trophic and the spatial networks were modular and specialized. Trophic modules matched medium-sized birds with fleshy-fruited trees, and small bird and mammals with small-fruit trees and shrubs. Spatial modules associated birds with woody canopies, and mammals with open habitats. Frugivore species maintained their structural role across the trophic and spatial networks of seed dispersal, even after accounting for frugivore abundance and body mass. 5. The modularity found in our system points to complementarity between birds and mammals in the seed dispersal process, a fact that may trigger landscape-scale secondary succession. Our results open up the possibility of predicting the consumption pattern of a diverse frugivore community, and its ecological consequences, from the uneven distribution of fleshy-fruit resources in the landscape

Zooming into plant-flower visitor networks: an individual trait-based approach

Understanding how ecological communities are structured is a major goal in ecology. Ecological networks representing interaction patterns among species have become a powerful tool to capture the mechanisms underlying plant-animal assemblages. However, these networks largely do not account for inter-individual variability and thus may be limiting our development of a clear mechanistic understanding of community structure. In this study, we develop a new individual-trait based approach to examine the importance of individual plant and pollinator functional size traits (pollinator thorax width and plant nectar holder depth) in mutualistic networks. We performed hierarchical cluster analyses to group interacting individuals into classes, according to their similarity in functional size. We then compared the structure of bee-flower networks where nodes represented either species identity or trait sets. The individual trait-based network was almost twice as nested as its species-based equivalent and it had a more symmetric linkage pattern resulting from of a high degree of size-matching. In conclusion, we show that by constructing individual trait-based networks we can reveal important patterns otherwise difficult to observe in species-based networks and thus improve our understanding of community structure. We therefore recommend using both trait-based and species-based approaches together to develop a clearer understanding of the properties of ecological networks

Newly discovered seed dispersal system of Juniperus cedrus questions the pristine nature of the high elevation scrub of El Teide (Tenerife, Canary Islands)

As a working hypothesis, we examined evidence for the former presence of a climacic woodland of Juniperus cedrus above the pine forest in the high elevation area of Tenerife (Canary Islands), which would indicate that the current dominant vegetation (endemic Spartocytisus supranubius scrub) may not be pristine. The main causes of the great regression of this woodland were caused by human activities (timber harvesting, herbivory by goats, and fires). The main support for this hypothesis is the survival of a presumably relict seed dispersal system of the endangered endemic J. cedrus, which relies mainly on the wintering thrush Turdus torquatus. The fact that genetic factors are directly involved in the control of bird migration routes strongly supports the idea that this interaction could be remnant of an older system, probably more widespread in the past. To test this hypothesis, we propose that a paleoecological approach could reconstruct the vegetation dynamics in the Teide National Park (Tenerife) and the past presence of this seed disperser migratory thrush. The analysis of plant microfossils in sediments (e.g., pollen, spores, phytoliths, coprolites, and charcoal) would allow us to evaluate whether the current vegetation is the same as that which naturally existed in the past, and assess the impact of the anthropogenic and natural factors to which it has been subjected during history. The results of these analyses will be useful for future management policies and practices aimed at restoring the pristine landscape and biotic interactions of the Teide National Park. To our knowledge, the case presented in this contribution, based on the high dependence of the seed dispersal of an endemic tree (J. cedrus) on a migratory bird, is the only reported in the context of oceanic islands.Ministerio de Ciencia e InnovaciónGobierno de las Islas CanariasOrganismo Autónomo de Parques Nacionale

Caring international research collaborative: A five-country partnership to measure perception of nursing staffs' compassion fatigue, burnout, and caring for self

Partnering in research across disciplines and across countries can be challenging due to differing contexts of practice and culture. This study sought to demonstrate how central constructs that have application across disciplines and countries can be studied while concurrently considering context. Groups of nurses from Botswana, Ireland, Israel, New Zealand, and Spain partnered to identify how to measure the constructs of caring for self, burnout, and compassion fatigue, replicating a study by Johnson (2012), who found that caring for self had a moderately strong negative relationship with both compassion fatigue and burnout. While these constructs were of interest to all five groups, the conversation of contextual influences varied. All five groups used the same instruments to measure the central constructs. Levels of burnout and compassion fatigue varied by country but were moderated by caring for self. Partnering across countries made it possible to understand that caring for self moderates the negative impact of burnout and compassion fatigue in all five countries. This study gives insight into methods for partnering across disciplines and contexts

Trophic strategies of Yellow-legged Gull Larus michahellis on oceanic islands surrounded by deep waters

[Capsule] The diet of Yellow-legged Gulls Larus michahellis on an oceanic island, surrounded by deep waters without a wide shelf, was mainly composed of terrestrial invertebrates. [Aims] To study the trophic ecology of Yellow-legged Gulls on an island surrounded by deep waters, to quantify the importance of terrestrial prey items and their availability, and to evaluate the relative importance of nutritional values of terrestrial and marine resources. [Methods] Diet was monitored for one year. We assessed the relative contribution of the main prey items and their macronutrients through the study of pellets and faeces. Results: Terrestrial invertebrates were the most frequently consumed prey items (frequency of occurrence (FO) 67%), followed by marine fish (Osteichthyes FO 33%). Coleoptera and Orthoptera were the most consumed terrestrial invertebrates and provided a high nutritional value. The rate of consumption of terrestrial invertebrates varied in synchrony with the breeding season, being higher in spring, indicating their potential importance for reproduction. [Conclusion] It is unusual that terrestrial invertebrates constitute a large proportion of the diet of large gulls, but they seemed to cover their trophic energy requirements during the reproductive period

Phylogeography and genetic structure of the threatened Canarian Juniperus cedrus (Cupressaceae)

We used plastid sequences (trnL, trnL-trnF, petN-psbM and trnT-trnL) to infer the phylogenetic relationships and inter-island connections of the Canarian Juniperus cedrus, and AFLP fingerprints to assess its genetic diversity patterns. Maximum Likelihood, Maximum Parsimony and Bayesian methods suggest independent colonization events for the three Macaronesian junipers and support the monophyly of J. cedrus. Plastid sequences reveal a low genetic diversity (three haplotypes) and do not provide sufficient information to resolve its temporal and geographical origin. AFLPs indicate a greater isolation in J. cedrus than in other Macaronesian trees with similar distributions and dispersal syndromes. Gran Canaria harbours the least genetically diverse population, which justifies immediate conservation actions. This island and Tenerife also show independent genetic structure, meaning that genetic exchange from other islands should be avoided in eventual reinforcements. Populations from La Palma and La Gomera show the highest genetic diversity levels and number of polymorphic AFLPs, probably because a lower incidence of felling has allowed a less dramatic influence of genetic bottlenecks. We suggest that management efforts should prioritize populations from these islands to preserve the evolutionary potential of the species, but we also stress the importance of knowledge of the evolutionary history, genetic structure and ecological interactions in conservation strategies.J. L. Blanco-Pastor helped us with phylogenetic data analyses. B. Rumeu was funded by a Spanish National Research Council grant (CSIC: JAE-PRE). This work was supported by projects co-funded by the Spanish ‘Ministerio de Ciencia e Innovación’ (CGL2010-18759), the ‘Gobierno de Canarias’ (PI2007/05) and the European Union. The ‘Organismo Autónomo de Parques Nacionales’ (project 051/2010) also financed part of this work.Peer Reviewe

Trophic strategies of Yellow-legged Gull <i>Larus michahellis</i> on oceanic islands surrounded by deep waters

<p><b>Capsule:</b> The diet of Yellow-legged Gulls <i>Larus michahellis</i> on an oceanic island, surrounded by deep waters without a wide shelf, was mainly composed of terrestrial invertebrates.</p> <p><b>Aims:</b> To study the trophic ecology of Yellow-legged Gulls on an island surrounded by deep waters, to quantify the importance of terrestrial prey items and their availability, and to evaluate the relative importance of nutritional values of terrestrial and marine resources.</p> <p><b>Methods:</b> Diet was monitored for one year. We assessed the relative contribution of the main prey items and their macronutrients through the study of pellets and faeces.</p> <p><b>Results:</b> Terrestrial invertebrates were the most frequently consumed prey items (frequency of occurrence (FO) 67%), followed by marine fish (Osteichthyes FO 33%). Coleoptera and Orthoptera were the most consumed terrestrial invertebrates and provided a high nutritional value. The rate of consumption of terrestrial invertebrates varied in synchrony with the breeding season, being higher in spring, indicating their potential importance for reproduction.</p> <p><b>Conclusion:</b> It is unusual that terrestrial invertebrates constitute a large proportion of the diet of large gulls, but they seemed to cover their trophic energy requirements during the reproductive period.</p

Revisión de la literatura periodontal 1991

La revisión de la literatura periodontal del año 1991 se divide en cuatro temas principales: Etiología, Diagnóstico, Tratamiento y Mantenimiento