Bes M., Corbera J., Sayol F., Bagaria G., Jover M., Preece C., Viza A., Sabater F., Fernández-Martínez M. (2018) On the influence of water conductivity, pH and climate on bryophyte assemblages in Catalan semi-natural springs. Journal of Bryology. : 1-10.EnllaçDoi: 10.1080/03736687.2018.1446484
Bryophytes are some of the most sensitive biological indicators of environmental change. Springs have a significant presence of bryophytes and so are ideal habitats for studying their relationship with the environment. We tested whether bryophyte assemblages can be explained with macro-, meso- and micro-ecological variables (i.e. seasonal climate, altitude, water pH and conductivity) sampling bryophytes from 198 semi-natural springs distributed along montane regions in the north-eastern Iberian Peninsula. We tested the influence of environmental variables on bryophyte assemblages in springs using sparse Partial Least Squares. Our results show that variability in bryophyte assemblages is explained by seasonal climate (temperature and precipitation from winter, spring, summer and autumn and temperature and precipitation seasonality), altitude and water conductivity. The results obtained by the present study will be useful for predicting bryophyte diversity in springs using simple and easy to obtain variables such as climate, water pH and conductivity. © British Bryological Society 2018
Ducatez S., Sayol F., Sol D., Lefebvre L. (2018) Are Urban Vertebrates City Specialists, Artificial Habitat Exploiters, or Environmental Generalists?. Integrative and comparative biology. 58: 929-938.EnllaçDoi: 10.1093/icb/icy101
Although urbanization is a major threat to biodiversity, some species are able to thrive in cities. This might be because they have specific adaptations to urban conditions, because they are able to cope with artificial habitats in general or because they are generalists that can live in a wide range of conditions. We use the latest version of the IUCN database to distinguish these possibilities in 25,985 species of the four classes of terrestrial vertebrates with the help of phylogenetically controlled methods. We first compare species occurrence in cities with that of the five other artificial habitats recognized by the IUCN and use principal components analyses to ask which of these most resembles cities. We then test whether urban species have a wider habitat breadth than species occurring in other, non-urban, artificial habitats, as well as species that occur only in natural habitats. Our results suggest that the proportion of terrestrial vertebrates that occur in urban environments is small and that, among the species that do occur in cities, the great majority also occur in other artificial habitats. Our data also show that the presence of terrestrial vertebrates in urban habitats is skewed in favor of habitat generalists. In birds and mammals, species occurrence in urban areas is most similar to that of rural gardens, while in reptiles and amphibians, urban areas most resemble pasture and arable land. Our study suggests that cities are likely not unique, as is often thought, and may resemble other types of artificial environments, which urban exploiters can adapt to because of their wide habitat breadth.
Sayol F., Downing P.A., Iwaniuk A.N., Maspons J., Sol D. (2018) Predictable evolution towards larger brains in birds colonizing oceanic islands. Nature Communications. 9: 0-0.EnllaçDoi: 10.1038/s41467-018-05280-8
Theory and evidence suggest that some selective pressures are more common on islands than in adjacent mainland habitats, leading evolution to follow predictable trends. The existence of predictable evolutionary trends has nonetheless been difficult to demonstrate, mainly because of the challenge of separating in situ evolution from sorting processes derived from colonization events. Here we use brain size measurements of >1900 avian species to reveal the existence of one such trend: increased brain size in island dwellers. Based on sister-taxa comparisons and phylogenetic ancestral trait estimations, we show that species living on islands have relatively larger brains than their mainland relatives and that these differences mainly reflect in situ evolution rather than varying colonization success. Our findings reinforce the view that in some instances evolution may be predictable, and yield insight into why some animals evolve larger brains despite substantial energetic and developmental costs. © 2018, The Author(s).
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