Sol D.,CREAF |
Gonzalez-Lagos C.,CREAF |
Gonzalez-Lagos C.,Austral University of Chile |
Moreira D.,University of Alberta |
And 2 more authors.
Ecology Letters | Year: 2014
Urbanisation is considered an important driver of current biodiversity loss, but the underlying causes are not fully understood. It is generally assumed that this loss reflects the fact that most organisms do not tolerate well the environmental alterations associated with urbanisation. Nevertheless, current evidence is inconclusive and the alternative that the biodiversity loss is the result of random mechanisms has never been evaluated. Analysing changes in abundance between urbanised environments and their non-urbanised surroundings of > 800 avian species from five continents, we show here that although random processes account for part of the species loss associated with urbanisation, much of the loss is associated with a lack of appropriate adaptations of most species for exploiting resources and avoiding risks of the urban environments. These findings have important conservation implications because the extinction of species with particular features should have higher impact on biodiversity and ecosystem function than a random loss. © 2014 John Wiley & Sons Ltd/CNRS.
Sayol F.,CREAF |
Lefebvre L.,CREAF |
Lefebvre L.,McGill University |
Brain, Behavior and Evolution | Year: 2016
Despite growing interest in the evolution of enlarged brains, the biological significance of brain size variation remains controversial. Much of the controversy is over the extent to which brain structures have evolved independently of each other (mosaic evolution) or in a coordinated way (concerted evolution). If larger brains have evolved by the increase of different brain regions in different species, it follows that comparisons of the whole brain might be biologically meaningless. Such an argument has been used to criticize comparative attempts to explain the existing variation in whole-brain size among species. Here, we show that pallium areas associated with domain-general cognition represent a large fraction of the entire brain, are disproportionally larger in large-brained birds and accurately predict variation in the whole brain when allometric effects are appropriately accounted for. While this does not question the importance of mosaic evolution, it suggests that examining specialized, small areas of the brain is not very helpful for understanding why some birds have evolved such large brains. Instead, the size of the whole brain reflects consistent variation in associative pallium areas and hence is functionally meaningful for comparative analyses. © 2016 S. Karger AG, Basel.
Arnan X.,CREAF |
Cerda X.,TU Darmstadt |
Rodrigo A.,University of Barcelona |
Retana J.,CSIC - Doñana Biological Station
Ecography | Year: 2013
Little is known about the impact of disturbances on functional diversity and the long-term provisioning of ecosystem services, especially in animals. In this work we analyze the effect of wildfire on the functional composition of Mediterranean ant communities. In particular, we asked whether a) fire changes functional composition (mean and dissimilarity of trait values) at the community level; and b) such fire-induced functional modification is driven by changes in the relative abundance-dominance of species or by a replacement of species with different traits. We sampled ant communities in burned and unburned plots along 22 sites in a western Mediterranean region, and we computed two complementary functional trait composition indices ('trait average' and 'trait dissimilarity') for 12 functional traits (related to resource exploitation, social structure and reproduction) and with two different datasets varying in the way species abundance is considered (i.e. abundance and occurrence data). Our results suggest a set of functional responses that seem to be related to direct mortality by fire as well as to indirect fire-induced modifications in environmental conditions relevant for ants. Trait average of colony size, worker size, worker polymorphism and the ratio between queen and worker size, as well as the trait dissimilarity of the proportion of behaviorally dominant species and of liquid food consumption, and overall functional diversity, were higher in burned than in unburned areas. Interestingly, different patterns arise when comparing results from abundance and occurrence data. While the response to fire in trait averages is quite similar, in the case of trait dissimilarity, the higher values in response to fire are much more marked when considering occurrence rather than abundance data. Our results suggest that changes in trait average are driven at the same time by replacement of species with different traits and by changes in the relative abundance-dominance of species, while fire promotes a higher diversity of functions that is primarily driven by rare species that are functionally unique. Overall, we observed major fire-induced changes in functional composition in Mediterranean ant communities that might have relevant consequences for ecosystem processes and services. © 2013 The Authors.
Izquierdo R.,CREAF |
Avila A.,CREAF |
Alarcon M.,Polytechnic University of Catalonia
Atmospheric Environment | Year: 2012
The aim of this study is to interpret the variation of precipitation chemistry during the last 25 years in Montseny (NE Spain) by taking into account the main air mass transport routes and emission sources. To this end, trajectory cluster analysis and source-receptor models were applied to an early monitoring period (1984-1993) and compared to a more recent one (1998-2009). A decrease of Atlantic advections and increase of African and European air flows was found. Cluster analysis and source-receptor approaches showed that this region is under the influence of natural and anthropogenic sources from the local and long-range scale. Sulphate and H + source areas extended over a vast stretch of central Europe in the early period, but were drastically reduced in the recent period, showing the effectiveness of pollution abatement measures for S. On the other hand, NO 3 - sources areas from central Europe strikingly increased. Ship emissions and industrialisation in Eastern Europe and North Africa seem to be acquiring a greater role in the recent period. © 2012 Elsevier Ltd.
Peguero G.,CREAF |
Biotropica | Year: 2014
Endozoochory and fire are crucial ecological factors determining germination success and recruitment in many plant species. Fire is a well-known germination trigger while endozoochory may allow seed dispersal along with an increase in germination. Their interaction has rarely been addressed, however, even though both factors are pervasive in human-transformed ecosystems like most Neotropical Dry Forests (NDF). For three common Mesoamerican tree species (Acacia pennatula, Enterolobium cyclocarpum, and Guazuma ulmifolia), we used feeding trials to assess the preference of cattle, which are their main seed dispersal agent. We also experimentally tested the interaction between gut passage and fire as triggers of germination. The fruits of the three species were eaten by cattle, but the small seeds of G. ulmifolia were ingested 10-fold more than those of the other species. While gut passage did not have any effect on germination, heat-shocks above 90 °C increased the number of germinating seeds by 15 percent. These results suggest that cattle may be a key dispersal vector in NDF, but that fire may be an important germination trigger. Physical dormancy in these species may have been selected for by extinct megaherbivores because it was a key trait ensuring seed survival after gut passage. However, in light of the recent expansion of cattle-ranching and fire occurrence in NDF, it has become a useful exaptation facilitating the colonization of disturbed areas. © 2013 The Association for Tropical Biology and Conservation.
Fernandez-Martinez M.,CREAF |
Belmonte J.,Autonomous University of Barcelona |
Maria Espelta J.,CREAF
Acta Oecologica | Year: 2012
Quercus species exhibit an extreme inter-annual variability in seed production often synchronized over large geographical areas (masting). Since this reproductive behavior is mostly observed in anemophilous plants, pollination efficiency is suggested as one hypothesis to explain it, although resource-based hypotheses are also suggested as alternatives. We analyzed the effect of flowering phenology, airborne pollen presence and meteorological conditions in the pattern of acorn production in mixed evergreen-deciduous oak forests (Quercus ilex and Quercus pubescens) in NE Spain for twelve years (1998-2009). In both oaks, higher temperatures advanced the onset of flowering and increased the amount of airborne pollen. Nevertheless, inter-annual differences in pollen production did not influence acorn crop size. Acorn production was enhanced by a delay in flowering onset in Q. ilex but not in Q. pubescens. This suggests that in perennial oaks a larger number of photosynthates produced before flowering could benefit reproduction while the lack of effects on deciduous oaks could be because these species flush new leaves and flowers at the same time. Notwithstanding this effect, spring water deficit was the most relevant factor in explaining inter-annual variability in acorn production in both species. Considering that future climate scenarios predict progressive warmer and dryer spring seasons in the Mediterranean Basin, this might result in earlier onsets of flowering and higher water deficits that would constrain acorn production. © 2012 Elsevier Masson SAS.
Sol D.,CREAF |
Sayol F.,CREAF |
Ducatez S.,University of Sydney |
Lefebvre L.,CREAF |
Lefebvre L.,McGill University
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2016
The evolutionary origin of innovativeness remains puzzling because innovating means responding to novel or unusual problems and hence is unlikely to be selected by itself. A plausible alternative is considering innovativeness as a co-opted product of traits that have evolved for other functions yet together predispose individuals to solve problems by adopting novel behaviours. However, this raises the question of why these adaptations should evolve together in an animal. Here, we develop the argument that the adaptations enabling animals to innovate evolve together because they are jointly part of a life-history strategy for coping with environmental changes. In support of this claim, we present comparative evidence showing that in birds, (i) innovative propensity is linked to life histories that prioritize future over current reproduction, (ii) the link is in part explained by differences in brain size, and (iii) innovative propensity and life-history traits may evolve together in generalist species that frequently expose themselves to novel or unusual conditions. Combined with previous evidence, these findings suggest that innovativeness is not a specialized adaptation but more likely part of a broader general adaptive system to cope with changes in the environment. © 2016 The Author(s) Published by the Royal Society. All rights reserved.
Rojas C.,University of Concepción |
Pino J.,CREAF |
Pino J.,University of Barcelona |
Jaque E.,University of Concepción
Land Use Policy | Year: 2013
This work describes a methodology for Strategic Environmental Assessment of urban areas in Latin America based on the recently approved European Planning Directive, and applies it to the Metropolitan Area of Concepción (Chile). The method is based on the Land Suitability Index (LSI), a cartographic GIS-based index originally developed for the region of Barcelona (Spain) and aimed at determining the suitability of each point in a region for urban development, considering three sub-indexes: (i) Naturalness, (ii) Ecological Connectivity and (iii) Natural Risk. Using the LSI we evaluated the already approved urban plans of the municipalities in the region, considering two scenarios: the initial land use or baseline scenario (S0) and the designated land use or planned scenario (S1). The results show that overall the planned scenario will result in a loss of around 16% of naturalness, with particularly negative effects on brushwood and wetland areas. Connectivity will decrease by around 17%, and urban areas exposed to many types of natural risks will increase considerably, from approximately 49% to 92% of the total urban surface. Finally the LSI shows that around 252 ha are suitable for new urbanization in the extension area. This corresponds to around 0.7% of the total extension area (37.381 ha), which represents 12% of the region (271.398 ha). We propose this methodology can be a valuable contribution to the design of Strategic Environmental Assessment applications and indicators for land planning in Latin America. © 2012 Elsevier Ltd.
Sardans J.,Global Ecology Unit CREAF CEAB UAB |
Ecohydrology | Year: 2014
Hydraulic lift, water movement from deep to upper soil layers by roots, is a widespread process in temperate and semi-arid environments. It can contribute 17-81% of total water transpired and favour the uptake of nutrients available mainly from soil organic matter decomposition (e.g. N). Downward siphoning, water movement from upper to deep soil layers, can represent 10-60% of total transpired water, favouring the uptake of nutrients supplied mainly from the leaching of bedrock minerals (e.g. P and K). These vertical water movements also can affect the N:P ratio of runoff waters when, in the case of hydraulic lift, they open the possibility for a given pulse of water to circulate multiple times across the N-rich upper soil layers. Plants, thus, affect the stoichiometry of nutrients in soils and groundwater not only through the physical protection of the soil and through the water uptake but also through water redistribution. Soil water redistribution can also play an outstanding role in the ecosystem responses to global change drivers. The increase in soil patchiness in current and future arid lands modifies runoff fluxes, hydraulic lift and downward siphoning, allowing plants to dispose of higher water and nutrient availabilities. The higher use of hydraulic lift and/or downward siphoning by alien species is a possible cause of alien plant success. Further mechanistic and quantitative research is thus warranted to discern the plant role in water and nutrient cycling and in the responses to global change. © 2014 John Wiley & Sons, Ltd.
Izquierdo R.,CREAF |
Journal of Atmospheric Chemistry | Year: 2012
Wet-only, dry-only, bulk deposition and deposition of sedimentary particles and gases deposited after the last rain (DAR) were collected weekly at La Castanya station in the Montseny mountains (NE Spain, 41 46′N, 2 21′E) from February 2009 to July 2010. These samples were analysed for pH, alkalinity, and the concentrations of major ions (Cl-, NO 3 -, SO4 2-, Na+, K +, Ca2+, Mg2+, NH4 +). Significant differences were observed between bulk and wet-only precipitation, with an enrichment of ions associated to coarse particles in bulk deposition. The comparison between wet and dry fluxes revealed that the removal of compounds at Montseny occurred mainly by wet deposition, which accounted for 74 % of total deposition. The dry flux was characterised by the predominance of K +, Ca2+ and Mg2+, which are related to coarse particles. Bulk collection methods at Montseny were considered representative of total atmospheric deposition, since bulk deposition plus DAR accounted for 97 % of total deposition measured with wet and dry-only collection devices. Thus, bulk deposition collectors can be recommended for deposition networks at remote sites (lacking electricity connection) in environments, where coarse particles are a predominant fraction of the aerosol mass. © 2013 Springer Science+Business Media Dordrecht.