Browsing by Subject "Species distribution models"

Now showing 1 - 5 of 5
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    Dataset for: Ecological niche centrality explains spatial variation in the abundance of South American swans: a continental assessment with conservation implications
    (2025) Allendes-Muñoz, Carolina; Miranda-Cavallieri, Marcelo; Matus-Olivares, Camilo; Carrasco-Barra, Jaime; García-Gonzalo, Jordi; González-Olabarria, José Ramón; Robledano Aymerich, Francisco; Lisón Gil, Fulgencio; Ecología e Hidrología; Facultad de Biología
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    Distribution and behaviour of striped dolphins in the southwestern Mediterranean Sea based on whale-watching data
    (Pergamon-Elsevier Science Ltd, 2023-10-31) Canales Cáceres, Rosa; Gomariz Castillo, Francisco; Alonso Sarria, Francisco; Abel, Isabel; Gimenez Casalduero, Francisca; Geografía
    The striped dolphin (Stenella coeruleoalba) is a cosmopolitan cetacean and the most commonly sighted dolphin in the Mediterranean Sea. It usually appears in groups of very different sizes, ranging from less than ten to more than 500 individuals, although it is usually found in groups of between 21 and 50 individuals. In the western Mediterranean, and more specifically in the Gulf of Mazarrón, S. coeruleoalba was the most frequently sighted cetacean during the 1042 whale-watching trips. The goal of this study was to establish the spatial and temporal distribution of striped dolphin sightings along the Gulf of Mazarrón between 2004 and 2014. Spatial patterns were analysed using a Random Forest based Species Distribution Model to estimate the presence of the species. Twentythree variables (three geographic, one temporal, eight geomorphometric and twelve oceanographic) were used as predictors. Out of the 1042 cruises, 872 records of striped dolphins were obtained. Some variations in the grouping patterns of these mammals were observed during the years 2006–2007, with an average shift in the size of the groups to fewer individuals (3−10). This variation is probably related to an epizootic event of morbillivirus occurring during those years, which was responsible for an abnormal rate of strandings of striped dolphins and long-finned pilot whales (Globicephala melas). The Random Forest model allowed to select 6 predictors related to morphometry and sea currents, suggesting the importance of specific habitat in offshore areas between 1000 and 3000 m depth in the continental slope
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    El Modelado de distribución de especies en los bosques de los andes meridionales
    (Universidad de Murcia, Servicio de Publicaciones, 2020) Alberdi Nieves, Virginia
    La elevada biodiversidad junto con una gran variedad de ecosistemas convierten a la Cordillera de los Andeses una de las regiones de mayor diversidad ambiental del mundo, donde se encuentran los rangos más extremos de tipos de paisajes, clima y formaciones forestales de la Tierra, un área adecuada para estudiar los posibles efectos del cambio climático sobre la distribución espacial de las formaciones forestales. Para ello resulta imprescindible entender los efectos de cambio climático en la zona, dónde las observaciones climáticas indican diferentes escenarios climáticos en el futuro, para un periodo de tiempo actual y para el periodo 2040-2069, con variaciones de las temperaturas y precipitaciones. Se analiza la distribución de los bosques a través de modelado predictivo con el método de máxima entropía de MaxEnt. Los resultados señalan que la mayoría de las formaciones forestales de los bosques andinos analizados tendrán previsiblemente problemas importantes en un futuro próximo, consecuencia de la pérdida de idoneidad climática en el área actual de distribución y del cambio geográfico de las áreas potencialmente adecuadas en el futuro como reflejan los resultados.
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    The relict population of Pinna nobilis in the Mar Menor is facing an uncertain future
    (Pergamon-Elsevier Science Ltd, 2022-11-21) Cortés Melendreras, Emilio; Gomariz Castillo, Francisco; Alonso Sarria, Francisco; Giménez Martín, Francisco J.; Murcia, Javier; Canales Cáceres, Rosa; Ramos Esplá, Alfonso A.; Barberá, Carmen; Gimenez Casalduero, Francisca; Geografía
    Pinna nobilis is undergoing one of the most dramatic events suffered by an endangered species. An emerging disease has relegated its populations to coastal lagoons or estuaries with salinities beyond the 36.5–39.7 psu range. The Mar Menor is one of two such locations on the Spanish coastline. Poor environmental conditions and eutrophication and anoxia events, that became critical in 2016, 2019 and 2021, have reduced its population in >99 %. In this work, the spatial distribution of the species within the lagoon and the factors determining its survival along the successive crises of eutrophication are studied using a two-stage (presence/absence estimation and density modelling) Species Distribution Model. A potential area of 200.97 ha and an average density of 1.05 ind.100 m2 is estimated for 2020. The viability of the Mar Menor population depends on management actions designed both for the species and to improve the lagoon environmental state.
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    Wintering raptor species distribution in a semiarid Mediterranean region: the relevance of lowlands and open habitats as stopover sites
    (Springer, 2024-03-08) Alvarez Martinez, M.; Leon Ortega, M.; Martinez Torrecilllas, J. E.; Calvo Sendin, J. F.; Jiménez Franco, María Victoria; Ecología e Hidrología
    As land-use cover types affect wintering birds’ strategies, studying their habitat suitability for species conservation is relevant. Predictive spatial models are considered excellent tools for conservation planning and improving our understanding of species distribution. Here we build models to predict the spatial distribution of raptor species that overwinter in SE Spain. We modelled the wintering raptor species distribution based on the presence-only data obtained between 2017 and 2019 and analysed their habitat preferences based on elevation and land-use cover variables. Our results show that altitude and distance to the coastline are the most important environmental factors to affect most species’ habitat suitability. Habitat type-related factors are other important predictors, and raptors subject of this study prefer lowlands and areas close to the coastline for overwintering by selecting open habitats, which include wetlands and irrigated and rainfed crops. This study highlights the importance of the habitat heterogeneity generated by wetlands and herbaceous crops within a low-altitude range as the optimal environment for wintering raptors. Such information should be considered for raptor conservation planning in human-altered landscapes.