29 research outputs found

    The significance of using satellite imagery data only in Ecological Niche Modelling of Iberian herps

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    The environmental data used to calculate ecological niche models (ENM) are obtained mainly from ground-based maps (e.g., climatic interpolated surfaces). These data are often not available for less developed areas, or may be at an inappropriate scale, and thus to obtain this information requires fieldwork. An alternative source of eco-geographical data comes from satellite imagery. Three sets of ENM were calculated exclusively with variables obtained (1) from optical and radar images only and (2) from climatic and altitude maps obtained by ground-based methods. These models were compared to evaluate whether satellite imagery can accurately generate ENM. These comparisons must be made in areas with well-known species distribution and with available satellite imagery and ground-based data. Thus, the study area was the south-western part of Salamanca (Spain), using amphibian and reptiles as species models. Models' discrimination capacity was measured with ROC plots. Models' covariation was measured with a Spatial Spearman correlation. Four modelling techniques were used (Bioclim, Mahalanobis distance, GARP and Maxent). The results of this comparison showed that there were no significant differences between models generated using remotely sensed imagery or ground-based data. However, the models built with satellite imagery data exhibited a larger diversity of values, probably related to the higher spatial resolution of the satellite imagery. Satellite imagery can produce accurate ENM, independently of the modelling technique or the dataset used. Therefore, biogeographical analysis of species distribution in remote areas can be accurately developed only with variables from satellite imagery

    Ampliación de la variabilidad genética de la colección de Aegilops conservada en ell CRF-INIA y caracterización molecular de las especies Neglecta y Geniculata

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    En este trabajo se expone el doble objetivo de incrementar la representación de la variabilidad genética de las especies Ae. geniculata, Ae. ventricosa, Ae. neglecta, y Ae. triuncialis que han evolucionado en España, y diferenciar correctamente las especies neglecta y geniculata

    Aumento de producción de líneas de trigo panadero con los genes H27 y H30 que confieren resistencia a Mayetiola destructor Say., transferidos desde Aegilops spp

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    Los resultados obtenidos en un ensayo de campo de una colección de líneas avanzadas de trigo con introgresión de los genes H27 y H30, que confieren resistencia frente al Mosquito del trigo (Mayetiola destructor), evidenciaron que alguna de estas líneas mejoraban significativamente la producción (142%) respecto al testigo susceptible, indicando su posible utilidad como variedades capaces de dar buen rendimiento en ausencia de tratamientos químicos (insecticidas) contra la plaga del mosquit

    Biogeographical patterns derived from remote sensing variables: the amphibians and reptiles of the Iberian Peninsula

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    The biogeographic patterns in species density of herptiles were analysed in the Iberian Peninsula. Geoclimatic regions were identified using a PCA. Individual habitat suitability (HS) models for 23 amphibians and 35 reptiles at 10 x 10 km scale were calculated with ENFA, using 12 environmental factors established with Remote Sensing (RS) techniques. The species presence proportion in each geoclimatic region was calculated through a cross-tabulation between each potential occurrence model and the geoclimatic regions. Species chorotypes were determined through Hierarchical Cluster Analysis using Jaccard's index as association measure and by the analysis of marginality and tolerance factors from individual HS models. Predicted species density maps were calculated for each geoclimatic region. Probable under-sampled areas were estimated through differences between the predicted species density maps and observed (Gap analysis). The selected PCA components divided the Iberian Peninsula in two major geoclimatic regions largely corresponding to the Atlantic and Mediterranean climates. The Jaccard's index clustered herptiles in two main taxonomic groups, with distribution similar to the Atlantic and Mediterranean geoclimatic regions (7 amphibian + 13 reptile species in three Atlantic subgroups and 16 amphibian + 22 reptile species in four Mediterranean subgroups). Marginality and tolerance factor scores identified species groups of herptile specialists and generalists. The highest observed and predicted species density areas were broadly located in identical regions. Predicted gaps are located in north-western, north-east and central Iberia. RS is a useful tool for biogeographical studies, as it provides consistent environmental data from large areas with high accuracy

    Infection structures of host-specialized isolates of Uromyces viciae-fabae and other species of Uromyces infecting leguminous crops

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    A study was made of the morphology of urediniospores and primary infection structures of 12 isolates of six legume-infecting species of Uromyces. Infection structures were sufficient to distinguish among species. Isolates of Uromyces viciae-fabae proved to be specialized with respect to host, because each isolate infected only cultivars of the species from which it was collected. Host-specialized isolates of U. viciae-fabae also were morphologically distinct, differing in both spore dimensions and infection structure morphology. In particular, the shape and dimensions of the substomatal vesicle were distinctive. These results support the view that U. viciae-fabae sensu lato is a species complex

    The significance of using satellite imagery data only in Ecological Niche Modelling of Iberian herps

    No full text
    The environmental data used to calculate ecological niche models (ENM) are obtained mainly from ground-based maps (e.g., climatic interpolated surfaces). These data are often not available for less developed areas, or may be at an inappropriate scale, and thus to obtain this information requires fieldwork. An alternative source of eco-geographical data comes from satellite imagery. Three sets of ENM were calculated exclusively with variables obtained (1) from optical and radar images only and (2) from climatic and altitude maps obtained by ground-based methods. These models were compared to evaluate whether satellite imagery can accurately generate ENM. These comparisons must be made in areas with well-known species distribution and with available satellite imagery and ground-based data. Thus, the study area was the south-western part of Salamanca (Spain), using amphibian and reptiles as species models. Models' discrimination capacity was measured with ROC plots. Models' covariation was measured with a Spatial Spearman correlation. Four modelling techniques were used (Bioclim, Mahalanobis distance, GARP and Maxent). The results of this comparison showed that there were no significant differences between models generated using remotely sensed imagery or ground-based data. However, the models built with satellite imagery data exhibited a larger diversity of values, probably related to the higher spatial resolution of the satellite imagery. Satellite imagery can produce accurate ENM, independently of the modelling technique or the dataset used. Therefore, biogeographical analysis of species distribution in remote areas can be accurately developed only with variables from satellite imagery
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