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Araújo R, Assis J, Aguillar R, Airoldi L, Bárbara I, Bartsch I et al. (2016)
Biodiversity and Conservation 25(7) 1319-1348.
A comprehensive expert consultation was conducted in order to assess the status, trends and the most important drivers of change in the abundance and geographical distribution of kelp forests in European waters. This consultation included an on-line questionnaire, results from a workshop and data provided by a selected group of experts working on kelp forest mapping and eco-evolutionary research. Differences in status and trends according to geographical areas, species identity and small-scale variations within the same habitat where shown by assembling and mapping kelp distribution and trend data. Significant data gaps for some geographical regions, like the Mediterranean and the southern Iberian Peninsula, were also identified. The data used for this study confirmed a general trend with decreasing abundance of some native kelp species at their southern distributional range limits and increasing abundance in other parts of their distribution (Saccharina latissima and Saccorhiza polyschides). The expansion of the introduced species Undaria pinnatifida was also registered. Drivers of observed changes in kelp forests distribution and abundance were assessed using experts’ opinions. Multiple possible drivers were identified, including global warming, sea urchin grazing, harvesting, pollution and fishing pressure, and their impact varied between geographical areas. Overall, the results highlight major threats for these ecosystems but also opportunities for conservation. Major requirements to ensure adequate protection of coastal kelp ecosystems along European coastlines are discussed, based on the local to regional gaps detected in the study.
Keyword: Kelp forests Expert consultation Status and tempor
Bellard C, Genovesi P, Jeschke J (2016)
Proceedings of the Royal Society B: Biological Sciences 283(1823) 20152454.
Biological invasions as drivers of biodiversity loss have recently been challenged. Fundamentally, we must know where species that are threatened by invasive alien species (IAS) live, and the degree to which they are threatened. We report the first study linking 1372 vertebrates threatened by more than 200 IAS from the completely revised Global Invasive Species Database. New maps of the vulnerability of threatened vertebrates to IAS permit assessments of whether IAS have a major influence on biodiversity, and if so, which taxonomic groups are threatened and where they are threatened. We found that centres of IAS-threatened vertebrates are concentrated in the Americas, India, Indonesia, Australia and New Zealand. The areas in which IAS-threatened species are located do not fully match the current hotspots of invasions, or the current hotspots of threatened species. The relative importance of biological invasions as drivers of biodiversity loss clearly varies across regions and taxa, and changes over time, with mammals from India, Indonesia, Australia and Europe are increasingly being threatened by IAS. The chytrid fungus primarily threatens amphibians, whereas invasive mammals primarily threaten other vertebrates. The differences in IAS threats between regions and taxa can help efficiently target IAS, which is essential for achieving the Strategic Plan 2020 of the Convention on Biological Diversity.
Keyword: Kelp forests Expert consultation Status and tempor
Bubadué J, Cáceres N, Carvalho R, Sponchiado J, Passaro F, Saggese F et al. (2016)
Hystrix, the Italian Journal of Mammalogy 27(2).
In South America, the crab-eating fox Cerdocyon thous occurs in sympatry to the ecologically similar, and phylogenetically close Lycalopex vetulus to the North, and Lycalopex gymnocercus to the South of its range. We studied character displacement in Cerdocyon under the effect of Bergmann's rule and the presence (or absence either) of Lycalopex within the crab-eating fox range. We performed skull shape analysis on 191 C. thous specimens and divided them in three distinct groups, depending on whether Cerdocyon occurs in sympatry or in allopatry to Lycalopex species. We tested for differences in size and shape between Cerdocyon groups and regressed both skull size and sexual size dimorphism against latitude and temperature, while controlling for spatial autocorrelation in the phenotypes. Southern Cerdocyon specimens present enlarged temporalis muscle and slender carnassial, both suggestive of a shift towards increased carnivory. Such a niche shift is interpreted as a mean to reduce competition to the larger Lycalopex species, which is still smaller than Cerdocyon . Consistently with the above, the degree of sexual shape and size dimorphism in Cerdocyon increases southward. We found a complex but coherent pattern of size and shape differentiation in Cerdocyon groups, which is consistent with the effects of both competition and Bergmann's rule. Cerdocyon reduces competition to Lycalopex by growing larger in the North. To the South, Cerdocyon is still larger, in keeping with Bergmann's rule, but strongly differs in skull shape from both its Lycalopex competitor and from any other Cerdocyon . Since the Southern Lycalopex species is much more similar in size to Cerdocyon than its Northern congeneric, this suggests that shape differences serve the goal of reducing competition between Cerdocyon and Lycalopex to the South, as size differences do to the North. The absence of the hypercarnivorous canid Speothos venaticus from the southern range of Cerdocyon may have allowed such a pattern to take place.
Keywords: Bergmann’s rule, Canidae, South America, character displacement, crab-eating fox, geometric morphometrics, sexual size dimorphism, shape disparity
Coro G, Magliozzi C, Vanden Berghe E, Bailly N, Ellenbroek A, Pagano P (2016)
Ecological Modelling 323 61-76.
Estimating absence locations of a species is important in conservation biology and conservation planning. For instance, using reliable absence as much as presence information, species distribution models can enhance their performance and produce more accurate predictions of the distribution of a species. Unfortunately, estimating reliable absence locations is difficult and often requires a deep knowledge of the species’ distribution and of its abiotic and biotic environmental preferences and tolerance. In this paper, we propose a methodology to reconstruct reliable absence information from presence-only information, and the conditions that those presence-only data have to meet to make this possible. Large species occurrence data collections (otherwise called occurrence datasets) contain high quality and expert-reviewed species observation records from scientific surveys. These surveys can be used to retrieve species presence locations, but they also record places where the species in their target list were not observed. Although these absences could be simply due to sampling variation, it is possible to intersect many of these reports to estimate true absence locations, i.e. those due to habitat unsuitability or geographical hindrances. In this paper, we present a method to generate reliable absence locations of this type for marine species, using scientific surveys reports contained in the Ocean Biogeographic Information System (OBIS), an authoritative species occurrence dataset. Our method spatially aggregates information from surveys focussing on the same target species. It detects absence locations for a given species as those locations in which repeated surveys (that included the species of interest in their target list) reported information only on other species. We qualitatively demonstrate the reliability of our method using distribution records of the Atlantic cod as a case study. Additionally, we quantitatively estimate its performance using another authoritative large species occurrence dataset, the Global Biodiversity Information Facility (GBIF). We also demonstrate that our approach has higher accuracy and presents complementary behaviour with respect to another method using environmental envelopes. Our process can support species distribution models (as well as other types of models, e.g. climate change models) by providing reliable data to presence/absence approaches. It can manage regional as well as global scale scenarios and runs within a collaborative e-Infrastructure (D4Science) that publishes it as-a-Service, allowing biologists to reproduce, repeat and share experimental results.
Keywords: Absence locations, Ecological niche modelling, Marine biodiversity, Occurrence data, Scientific surveys, Species distribution maps
Febbraro M, Martinoli A, Russo D, Preatoni D, Bertolino S (2016)
Hystrix, the Italian Journal of Mammalogy 27(1).
Assessing invasion risk by alien organisms implies evaluating the likelihood of successful establishment and spread once they are accidentally or deliberately introduced. The importance of implementing accurate risk–assessment procedures is further stressed by the evidence that ongoing climate change can promote invasion processes, from initial introduction through establishment and spread. Although squirrels are considered powerful invaders with well–documented negative impacts on biodiversity and human activities, there is a noticeable gap of comprehensive investigations specifically focused on this group, especially as far as the effect of climate change on worldwide invasion risk is concerned. In this study we predicted current and 2070 potential distributions of eight squirrel species with a SDM–based framework, also detecting current potential hotspots of invasion and evaluating how these could be modified by climate change in 2070. SDM predicted the eight species to potentially occur in large areas worldwide (12.12% to 39.23% of the mainland), with 70 to 129 countries vulnerable to a potential invasion. Model projections over the 2070 climate change scenarios predicted five to seven squirrel species undergoing an increase in their future potential distribution in non–native ranges. Current hotspots of potential invasion were predicted to occur in southeastern Asia, northeastern Australia, tropical Africa and South America, as well as Central and North America. Projections to 2070 showed most of the hotspots of invasion to remain substantially stable in terms of number of potential invasive species, regardless of the scenario. The most relevant increase/reduction in extent of species distribution and in the number of potential invasive species in invasiveness hotspots were predicted for 2070 under the most severe scenarios. We emphasize a strong species–specific response to climate change, which could also affect invasive species by making them less competitive, therefore potentially leading to a retreat from the invaded ranges.
Keywords: Sciuridae, biological invasions, conservation, management, risk-assessment, species introductions
Katsanevakis S, Tempera F, Teixeira H (2016)
Diversity and Distributions.
Aim To develop a standardized, quantitative method for mapping cumulative impacts of invasive alien species on marine ecosystems. Location The methodology is applied in the Mediterranean Sea but is widely applicable. Methods A conservative additive model was developed to account for the Cumulative IMPacts of invasive ALien species (CIMPAL) on marine ecosystems. According to this model, cumulative impact scores are estimated on the basis of the distributions of invasive species and ecosystems, and both the reported magnitude of ecological impacts and the strength of such evidence. In the Mediterranean Sea case study, the magnitude of impact was estimated for every combination of 60 invasive species and 13 habitats, for every 10 × 10 km cell of the basin. Invasive species were ranked based on their contribution to the cumulative impact score across the Mediterranean. Results The CIMPAL index showed strong spatial heterogeneity. Spatial patterns varied depending on the pathway of initial introduction of the invasive species in the Mediterranean Sea. Species introduced by shipping gave the highest impact scores and impacted a much larger area than those introduced by aquaculture and the Suez Canal. Overall, invasive macroalgae had the highest impact among all taxonomic groups. These results represent the current best estimate of the spatial variation in impacts of invasive alien species on ecosystems, in the Mediterranean Sea. Main Conclusions A framework for mapping cumulative impacts of invasive alien species was developed. The application of this framework in the Mediterranean Sea provided a baseline that can be built upon with future improved information. Such analysis allows the identification of hotspots of highly impacted areas, and prioritization of sites, pathways and species for management actions.
Keywords: CIMPAL, biological invasions, cumulative impacts, indicators, invasive alien species, pathways
Londei T (2016)
Piapiacs ( Ptilostomus afer Linnaeus, 1766) and yellow-billed oxpeckers ( Buphagus africanus Linnaeus, 1766) avoid proximity when on African buffaloes ( Syncerus caffer Sparrman, 1779)
African Journal of Ecology.
Many African bird species (totalling 96 according to Dean & MacDonald, 1981) show feeding associations with mammals. However, little attention, if any, has been paid to interspecific interactions among birds attending the same mammal. Moreover, except for the red-billed oxpecker (Buphagus erythrorhyncus Stanley, 1814) and yellow-billed oxpecker (Buphagus africanus Linnaeus, 1766), which are obligate ectoparasite gleaners, there are only suggestions for any of the other species about the extent of their dependence on mammals (Dean & MacDonald, 1981). The piapiac (Ptilostomus afer Linnaeus, 1766) is a savannah corvid of sub-Saharan Africa north of the equator, ranging west-eastwards from Senegal to extreme W Kenya (Madge, 2009). Considering its wide distribution, consistent numbers and conspicuous behaviour, it is an understudied species. It is frequently seen on the backs of slowly moving herbivorous mammals, which serve as lookouts not only to catch the insects which the mammal flushes from the ground, but also as feeding substrate for the mammal's ectoparasites. Analysis of stomach contents has been very scarce for the piapiac. Among the 181 specimens listed in the Global Biodiversity Information Facility (http://www.gbif.org/; accessed 25 March 2016), only five specimens (four of which collected in 2 days in the same area) had stomach contents reported, which were all insects, mainly grasshoppers. However, Wilson (1981) found ‘ticks’ in the one piapiac stomach he examined. The piapiac may be second to only the oxpeckers in its apparent (although still understudied) morphological specializations to use grazing mammals for foraging. Interestingly, the piapiac prefers balancing on, rather than clinging to, the mammal's body (Fig. 1). This may be the reason why elephants (Loxodonta africana Blumenbach, 1797) more easily tolerate piapiacs on their sensitive skin (see, e.g. Mundy & Haynes, 1996) and why oxpeckers and not piapiacs are usually found on the sloping back of giraffes (Giraffa camelopardalis Linnaeus, 1758). The search for a stable perch may also explain why piapiacs would especially be attracted to domestic ungulates, quieter animals than their wild counterparts. The suggestion of a partial niche overlap and consequent competition between piapiacs and oxpeckers prompted this study. I chose the African buffalo (Syncerus caffer Sparrman, 1779) as the associated mammal because of its apparent attractiveness for both the piapiacs and the oxpeckers, its abundance in the study area and it being the closest wild African relative of the domestic cattle to which the oxpeckers often become detrimental through wound-feeding (e. g., Weeks, 2000).
Keywords: CIMPAL, biological invasions, cumulative impacts, indicators, invasive alien species, pathways
Marta S, Lacasella F, Gratton P, Cesaroni D, Sbordoni V (2016)
Deciphering range dynamics: effects of niche stability areas and post-glacial colonization on alpine species distribution
Journal of Biogeography.
Aim Niche stability areas (NSAs) are portions of the species range where climate conditions remain suitable through time. They represent the core of species ranges. Their distribution and extent, coupled with dispersal and colonization, shape the realized range of species. In this study, we quantified the roles of survival within NSAs and post-glacial dispersal in determining the current distribution of two groups of alpine butterflies (two taxa in the Erebia tyndarus species complex; three taxa in the Parnassius apollo–P. phoebus species complex). Location Holarctic. Methods NSAs were identified for each taxon by combining current and past potential distributions models, estimated using different modelling techniques and general circulation models. We then (1) assessed the distributional bias towards NSAs by comparing actual occurrence records with randomized occupancies of the current potential range and (2) quantified post-glacial dispersal by examining the distribution of distances from each occurrence record to the nearest NSA. Results In almost all taxa, realized distributions are biased towards NSAs. However, while Erebia's present range is strongly dominated by NSAs, some populations of Parnassius are found very far from NSAs, suggesting more effective colonization of the available geographical space. Main conclusions Our study highlights the relative roles of survival within NSAs and post-glacial dispersal in shaping the ranges of different alpine butterflies during the Holocene. Results suggest that Erebia was unable to disperse far from NSAs, thus experiencing increasing range fragmentation. Parnassius populations, on the other hand, coupled local survival with northward dispersal. As NSAs allowed the long-term survival of the species, acting as sources for recolonization, and tend to preserve most of each species’ genetic diversity, identifying NSAs and understanding their importance in determining the current distribution of species represents a pivotal task for the conservation of biological diversity.
Keywords: Erebia, Parnassius, alpine species, butterflies, climate change, hindcasting, interglacial refugia, niche stability areas, species distribution modelling, species–climate equilibrium
Pierce S, Negreiros D, Cerabolini B, Kattge J, Díaz S, Kleyer M et al. (2016)
Competitor, stress-tolerator, ruderal (CSR) theory is a prominent plant functional strategy scheme previously applied to local floras. Globally, the wide geographic and phylogenetic coverage of available values of leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA) (representing, respectively, interspecific variation in plant size and conservative vs. acquisitive resource economics) promises the general application of CSR strategies across biomes, including the tropical forests hosting a large proportion of Earth's diversity. We used trait variation for 3068 tracheophytes (representing 198 families, six continents and 14 biomes) to create a globally calibrated CSR strategy calculator tool and investigate strategy–environment relationships across biomes world-wide. Due to disparity in trait availability globally, co-inertia analysis was used to check correspondence between a ‘wide geographic coverage, few traits’ data set and a ‘restricted coverage, many traits’ subset of 371 species for which 14 whole-plant, flowering, seed and leaf traits (including leaf nitrogen content) were available. CSR strategy/environment relationships within biomes were investigated using fourth-corner and RLQ analyses to determine strategy/climate specializations. Strong, significant concordance (RV = 0·597; P < 0·0001) was evident between the 14 trait multivariate space and when only LA, LDMC and SLA were used. Biomes such as tropical moist broadleaf forests exhibited strategy convergence (i.e. clustered around a CS/CSR median; C:S:R = 43:42:15%), with CS-selection associated with warm, stable situations (lesser temperature seasonality), with greater annual precipitation and potential evapotranspiration. Other biomes were characterized by strategy divergence: for example, deserts varied between xeromorphic perennials such as Larrea divaricata, classified as S-selected (C:S:R = 1:99:0%) and broadly R-selected annual herbs (e.g. Claytonia perfoliata; R/CR-selected; C:S:R = 21:0:79%). Strategy convergence was evident for several growth habits (e.g. trees) but not others (forbs). The CSR strategies of vascular plants can now be compared quantitatively within and between biomes at the global scale. Through known linkages between underlying leaf traits and growth rates, herbivory and decomposition rates, this method and the strategy–environment relationships it elucidates will help to predict which kinds of species may assemble in response to changes in biogeochemical cycles, climate and land use.
Keywords: Comparative ecology, Grime’s CSR triangle, community assembly, plant economics spectrum, plant functional type, survival strategy, universal adaptive strategy theory
Pranovi F, Anelli Monti M, Brigolin D, Zucchetta M (2016)
Frontiers in Marine Science 3 143.
Possible effects of the spatial scale of analysis on the relationship between fishery landings and the water temperature in the Mediterranean Sea have been investigated using the FAO capture database (1970-2010). The analysis was performed by dividing species in three thermal affinity categories: cold, temperate and hot species. Results showed significant changes in fishery landings composition during the last four decades, in terms of the relative contribution of cold, temperate and hot species to landings; moreover, the presence of a strong influence of water warming in determining the landings temporal pattern has been confirmed. This relationship, however, resulted to be not homogenous across the tested spatial scales (entire Mediterranean basin, three main sub-basins, eight FAO areas). The best models (based on the Akaike Information Criterion), were the ones fitted at the finer spatial definition (i.e. the eight FAO areas) for all the three thermal affinity categories. The recorded relationship showed clear differences in terms of direction, depending on both areas and thermal affinity groups. Cold species showed a negative relationship with the increasing water temperature in all the FAO areas, being partially replaced by temperate ones, with the exception of the Adriatic and Black Sea (the coldest areas in the Mediterranean basin), where a moderate increase in the water temperature is still favoring the cold affinity group. This kind of results could be useful within the context of the management plans definition, within a context of climate changes.
Keywords: Mediterranean Sea, SST, climate changes, fishery, landings, spatial scale