25 research outputs found

    Landscape metrics as indicators of coastal morphology and its use in ecological niche modelling of seagrass species

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    Dependence of some species on landscape structure has been proved in numerous studies. So far, however, little progress has been made in the integration of landscape metrics in the prediction of species associated with coastal features. Specific landscape metrics were tested as predictors of coastal shape using three coastal features of the Iberian Peninsula (beaches, capes and gulfs) at different scales. We used the landscape metrics in combination with environmental variables to model the niche and find suitable habitats for a seagrass species (Cymodocea nodosa) throughout its entire range of distribution. Landscape metrics able to capture variation in the coastline enhanced significantly the accuracy of the models, despite the limitations caused by the scale of the study. We provided the first global model of the factors that can be shaping the environmental niche and distribution of C. nodosa throughout its range. Sea surface temperature and salinity were the most relevant variables. We identified areas that seem unsuitable for C. nodosa as well as those suitable habitats not occupied by the species. We also present some preliminary results of testing historical biogeographical hypotheses derived from distribution predictions under Last Glacial Maximum conditions and genetic diversity data

    Marine forests of the Mediterranean-Atlantic Cystoseira tamariscifolia complex show a southern Iberian genetic hotspot and no reproductive isolation in parapatry

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    Climate-driven range-shifts create evolutionary opportunities for allopatric divergence and subsequent contact, leading to genetic structuration and hybrid zones. We investigate how these processes influenced the evolution of a complex of three closely related Cystoseira spp., which are a key component of the Mediterranean-Atlantic seaweed forests that are undergoing population declines. The C. tamariscifolia complex, composed of C. tamariscifolia s.s., C. amentacea and C. mediterranea, have indistinct boundaries and natural hybridization is suspected. Our aims are to (1) infer the genetic structure and diversity of these species throughout their distribution ranges using microsatellite markers to identify ancient versus recent geographical populations, contact zones and reproductive barriers, and (2) hindcast past distributions using niche models to investigate the influence of past range shifts on genetic divergence at multiple spatial scales. Results supported a single, morphologically plastic species the genetic structure of which was incongruent with a priori species assignments. The low diversity and low singularity in northern European populations suggest recent colonization after the LGM. The southern Iberian genetic hotspot most likely results from the role of this area as a climatic refugium or a secondary contact zone between differentiated populations or both. We hypothesize that life-history traits (selfing, low dispersal) and prior colonization effects, rather than reproductive barriers, might explain the observed genetic discontinuities.Pew Charitable Trusts (USA); MARINERA, Spain [CTM2008-04183-E/MAR]; FCT (Portugal) [FCT-BIODIVERSA/004/2015, CCMAR/Multi/04326/2013, SFRH/BPD/107878/2015, SFRH/BPD/85040/2012]; FPU fellowship of the Spanish Ministry of Education; European Community ASSEMBLE visiting grant [00399/2012]; University of Cadi

    Can we use niche models of indicator species to predict the distribution of endangered communities?

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    European-wide conservation policies are based on the identification of priority habitats. However, research on conservation biogeography often relies on the results and projections of species distribution models to assess species' vulnerability to global change. We assess whether the distribution and structure of threatened communities can be predicted by the suitability of the environmental conditions for their indicator species. We present some preliminary results elucidating if using species distribution models of indicator species at a regional scale is a valid approach to predict these endangered communities. Dune plant assemblages, affected by severe conditions, are excellent models for studying possible interactions among their integrating species and the environment. We use data from an extensive survey of xerophytic inland sand dune scrub communities from Portugal, one of the most threatened habitat types of Europe. We identify indicator shrub species of different types of communities, model their geographical response to the environment, and evaluate whether the output of these niche models are able to predict the distribution of each type of community in a different region

    Environmental drivers of distribution and reef development of the Mediterranean coral Cladocora caespitosa

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    Cladocora caespitosa is the only Mediterranean scleractinian similar to tropical reef-building corals. While this species is part of the recent fossil history of the Mediterranean Sea, it is currently considered endangered due to its decline during the last decades. Environmental factors affecting the distribution and persistence of extensive bank reefs of this endemic species across its whole geographic range are poorly understood. In this study, we examined the environmental response of C. caespitosa and its main types of assemblages using ecological niche modeling and ordination analysis. We also predicted other suitable areas for the occurrence of the species and assessed the conservation effectiveness of Mediterranean marine protected areas (MPAs) for this coral. We found that phosphate concentration and wave height were factors affecting both the occurrence of this versatile species and the distribution of its extensive bioconstructions in the Mediterranean Sea. A set of factors (diffuse attenuation coefficient, calcite and nitrate concentrations, mean wave height, sea surface temperature, and shape of the coast) likely act as environmental barriers preventing the species from expansion to the Atlantic Ocean and the Black Sea. Uncertainties in our large-scale statistical results and departures from previous physiological and ecological studies are also discussed under an integrative perspective. This study reveals that Mediterranean MPAs encompass eight of the ten banks and 16 of the 21 beds of C. caespitosa. Preservation of water clarity by avoiding phosphate discharges may improve the protection of this emblematic species.Spanish Ministry of Economy and Competitiveness [CTM2014-57949-R]info:eu-repo/semantics/publishedVersio

    A utilização do ATLANTIS – Tierra 2.0 e de ferramentas SIG para predizer a distribuição espacial e a adequação do habitat de espécies endémicas

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    O conhecimento da distribuição de espécies raras requer muito esforço devido às dificuldades inerentes à detecção das suas populações. Neste capítulo, apresenta-se um exemplo de modelação da distribuição potencial de espécies endémicas de insectos, que constituem uma preocupação de conservação nos Açores. São analisados dados extraídos da base de dados ATLANTIS com o objectivo de desenvolver mapas preditivos da distribuição de quatro escaravelhos endémicos (Insecta, Coleoptera) na ilha Terceira: Cedrorum azoricus azoricus Borges & Serrano, 1993; Trechus terceiranus Machado, 1988; Trechus terrabravensis Borges, Serrano & Amorim, 2004; e Alestrus dolosus (Crotch, 1867). São usadas duas técnicas amplamente aplicadas nestas situações (BIOCLIM e BioMapper) de forma a desenvolver os mapas de distribuição, mas igualmente a obter a descrição do nicho ecológico de cada espécie. Todas as espécies, excepto T. terceiranus, apresentam grandes restrições de habitat. As outras três espécies parecem estar ambientalmente restringidas a duas áreas espaciais bem definidas, localizadas nas partes oeste (Serra de Santa Bárbara) e central (Terra Brava) da ilha Terceira. Contudo, enquanto A. dolosus estará potencialmente espalhado em ambas as áreas, de acordo com os seus requisitos de habitat, C. azoricus azoricus e T. terrabravensis parecem possuir adaptações ambientais muito mais restritivas. No entanto, como os dados sobre a distribuição conhecida destas espécies se revelaram escassos, a eficácia dos mapas de predição não é propriamente a ideal. Deste modo, é discutida de forma exaustiva a utilidade das técnicas utilizadas, num contexto de gestão da conservação. São igualmente discutidos os problemas surgidos durante o processo de modelação dos dados e como estes podem ser resolvidos. Finalmente são apresentadas sugestões para melhorar a informação a obter da base de dados ATLANTIS.ABSTRACT: Ranges of rare species require great efforts to be mapped due to the low detect ability of their populations. In this chapter, we provide an example focusing on several endemic insect species of conservation concern in the Azores. We explore the use of data extracted from ATLANTIS database to develop predictive maps of the distribution of four endemic beetle species (Insecta, Coleoptera) in Terceira Island: Cedrorum azoricus azoricus Borges & Serrano, 1993; Trechus terceiranus Machado, 1988; Trechus terrabravensis Borges, Serrano & Amorim, 2004; and Alestrus dolosus (Crotch, 1867). We use two widely used methodologies (BIOCLIM and BioMapper) to develop such maps, as well as to provide a description of the niche of these species. All species except for T. terceiranus presented highly restricted habitat requirements. The other three species seem to be environmentally restricted to two spatially well-defined areas, placed in the west (Serra de Santa Bárbara) and the centre of the island (Terra Brava). However, while A. dolosus seems to be potentially widespread in these two areas according to its habitat requirements, C. azoricus azoricus and T. terrabravensis appear to have very restricted environmental adaptations. As data (recorded presences) for these species is scarce, the performance of the predictions was not ideal. Therefore, we discuss extensively the utility of such methodologies in the context of conservation management. We also discuss how the problems arose during this work can be overcome, and how ATLANTIS information could be improved

    Environmental variability in aquatic ecosystems: Avenues for future multifactorial experiments

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    The relevance of considering environmental variability for understanding and predicting biological responses to environmental changes has resulted in a recent surge in variability-focused ecological research. However, integration of findings that emerge across studies and identification of remaining knowledge gaps in aquatic ecosystems remain critical. Here, we address these aspects by: (1) summarizing relevant terms of variability research including the components (characteristics) of variability and key interactions when considering multiple environmental factors; (2) identifying conceptual frameworks for understanding the consequences of environmental variability in single and multifactorial scenarios; (3) highlighting challenges for bridging theoretical and experimental studies involving transitioning from simple to more complex scenarios; (4) proposing improved approaches to overcome current mismatches between theoretical predictions and experimental observations; and (5) providing a guide for designing integrated experiments across multiple scales, degrees of control, and complexity in light of their specific strengths and limitations

    Modelos predictivos aplicados a la conservación de invertebrados protegidos Ibero-baleares

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    196 páginas. Esta tesis doctoral consta de cuatro capítulosAnte la rápida desaparición de hábitats y especies, la necesidad de conservar la biodiversidad se enfrenta con la imposibilidad de inventariar y proteger todas las especies individualmente. Por un lado, nuestro conocimiento sobre la diversidad del planeta continua siendo insuficiente y son muchas las especies aún por describir (“Linnean Shortfall”; Brown & Lomolino, 1998) y asi mismo, desconocemos en gran medida la distribución local, regional o global de numerosos taxones (“Wallacean Shortfall”; Lomolino, 2004). El sesgo en el desconocimiento aumenta según los organismos sean más pequeños y complejos (Medellín & Soberón, 1999; Ødegaard, et al., 2000; Whittaker et al. , 2005) por lo que los taxones animales peor conocidos suelen ser grupos de invertebrados. Resulta por lo tanto esencial identificar las especies amenazadas y describir su distribución, mediante planteamientos de trabajo que no resulten inabarcables por falta de tiempo o presupuesto, problemas recurrentes con los que se enfrenta la planificación sistemática de la conservación. Durante las últimas décadas, se ha intentado priorizar la selección de reservas mediante la identificación de “hotspots” o zonas de máxima riqueza. Sin embargo, frecuentemente éstas no coinciden para taxones diferentes, las especies raras no están presentes en ellas o la congruencia entre los distintos índices de biodiversidad es baja (Prendergast et al., 1993; Orme et al., 2005; Grenyeret al., 2006). La utilización del criterio de complementariedad para la búsqueda de “huecos” (“gap analysis”; Scott et al., 1993) en la red de espacios protegidos es mucho más efectiva (Williams et al. , 1996; Katiet al., 2004) y su utilización en el caso de la Península Ibérica demuestra que se necesitan áreas protegidas adicionales a las existe ntes para la conservación efectiva de la diversidad de plantas y vertebrados (Araújo et al., 2007).This research was supported by the Spanish “Ministerio de Ciencia e Innovación” through the project CGL2008+03878. Fundación Banco Bilbao Vizcaya Argentaria Project (Diseño de una red de reservas para la protección de la Biodiversidad en América del sur austral utilizando modelos predictivos de distribución con taxones hiperdiversos) and a Ministerio de Educación y Ciencia Project (CGL20040+04309). Projects REN2001+1136/GLO (Spanish D.G.I.) a nd 07M/0080/2002 (Comunidad de Madrid). J.H. was supported by a Ph.D. Museo Nacional de Ciencias Naturales/C.S.I.C./Comunidad de Madrid grantPeer Reviewe

    Assessing the effects of pseudo-absences on predictive distribution model performance

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    Modelling species distributions with presence data from atlases, museum collections and databases is challenging. In this paper, we compare seven procedures to generate pseudoabsence data, which in turn are used to generate GLM-logistic regressed models when reliable absence data are not available. We use pseudo-absences selected randomly or by means of presence-only methods (ENFA and MDE) to model the distribution of a threatened endemic Iberian moth species (Graellsia isabelae). The results show that the pseudo-absence selection method greatly influences the percentage of explained variability, the scores of the accuracy measures and, most importantly, the degree of constraint in the distribution estimated. As we extract pseudo-absences from environmental regions further from the optimum established by presence data, the models generated obtain better accuracy scores, and over-prediction increases. When variables other than environmental ones influence the distribution of the species (i.e., non-equilibrium state) and precise information on absences is non-existent, the random selection of pseudo-absences or their selection from environmental localities similar to those of species presence data generates the most constrained predictive distribution maps, because pseudo-absences can be located within environmentally suitable areas. This study showsthat ifwe do not have reliable absence data, the method of pseudo-absence selection strongly conditions the obtained model, generating different model predictions in the gradient between potential and realized distributions

    Potential distribution modelling, niche characterization and conservation status assessment using GIS tools: A case study of Iberian Copris species

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    Dung beetle populations, in decline, play a critical ecological role in extensive pasture ecosystems by recycling organic matter; thus the importance of their conservation status. Presence data available for Copris hispanus (L.) and Copris lunaris (L.) (Coleoptera, Scarabaeidae) in Comunidad de Madrid (CM), and BIOMAPPER, a GIS-based tool, was used to model their environmental niches. The so derived potential distributions of both species were used to exemplify the utility of this kind of methodologies in conservation assessment, as well as its capacity to describe the potential sympatry between two or more species. Both species, distributed along a Dry-Mediterranean to Wet-Alpine environmental conditions gradient, overlap in areas of moderate temperatures and mean annual precipitations in the north of CM. Copris are poorly conserved in the existing protected sites network, but protection provided by new sites included in the future Natura 2000 Network will improve the general conservation status of these species in CM

    Efectos de las características ecológicas y de los datos sobre los modelos de distribución de invertebrados protegidos

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    Effects of species’ traits and data characteristics on distribution models of threatened invertebrates.— The lack of information about the distribution of threatened species inhibits the development of strategies for their conservation. This is a particularly important problem when considering invertebrates. Here we evaluate the effects of species’ traits and data characteristics on the accuracy of species distribution models (SDM) of 20 threatened Iberian invertebrates. We found that the accuracy of the predictions was mostly affected by the characteristics of the data. Species whose distributions were most accurately modelled were those with a greater sample size or smaller relative occurrence area (ROA). Species in habitats that were difficult to detect using GIS data, such as riparian species, tended to be more difficult to predict
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