The Experts below are selected from a list of 7926 Experts worldwide ranked by ideXlab platform
Manuel Hernandez Fernandez - One of the best experts on this subject based on the ideXlab platform.
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quantitative palaeoclimatic inference based on Terrestrial Mammal faunas
Global Ecology and Biogeography, 2005Co-Authors: Manuel Hernandez Fernandez, Pablo PelaezcampomanesAbstract:Aim The main goal of this paper is to propose a new tool, in the form of Quantitative Bioclimatic Models (QnBMs), for reconstructing past climates based on fossil Mammal associations. As a case study, European climatic conditions during the basal early Pleistocene will be inferred using QnBMs. Location The study uses faunas throughout the world to develop a quantitative bioclimatic model, which is then applied to Quaternary faunas from Eurasia. Methods The models were constructed by applying multivariate linear regression to modern Mammal faunas and climates from all over the world. The models were validated with a second group of modern faunas, which includes several from transitional zones between different climates (ecotones). To test the reliability of the method when applied to fossil associations, the results obtained for the Pleistocene have been compared with those obtained from palynology. Results Validation of the models shows that as many as 11 climatic factors can be inferred with high reliability using the regression models developed in this work. Comparisons of results in the late Pleistocene–Holocene of Barova (Czech Republic) between a palynological study and the quantitative bioclimatic analysis show a high degree of similarity. The results for the early Pleistocene show colder and drier climatic conditions for Europe than today. Main conclusions The application of the quantitative bioclimatic models to present day as well as Quaternary Mammal faunas proves to be a useful tool for palaeoclimatic reconstruction during the Quaternary and probably most of the Neogene. Transfer functions are presented for a complete set of climatic factors, allowing a precise estimation of the climate in a locality from its Mammal fauna.
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bioclimatic discriminant capacity of Terrestrial Mammal faunas
Global Ecology and Biogeography, 2001Co-Authors: Manuel Hernandez FernandezAbstract:A new method of environmental inference is presented. This method uses the climatic restriction index (CRI) for each Mammal species, based on its geographical range within different climatic regimes, and a set of calculated summary indexes known as the bioclimatic spectrum. Analysis of 50 faunas throughout the world shows that Terrestrial Mammal communities are effective tools for accurate climatic inference at large spatial scale. The results also indicate that the use of entire Mammalian fauna is the best inference system, followed by those based on separate groups such as Insectivora, Rodentia, microMammals and macroMammals. Removing Chiroptera from the analysis does not change the results significantly. Bioclimatic analysis appears to be a good method for environmental interpretation. This new method ensures a high qualitative precision. It provides an empirical model for Mammal community characterization that must be taken into account for palaeoclimatic reconstructions of continental environments.
Mauricio Eduardo Graipel - One of the best experts on this subject based on the ideXlab platform.
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atlantic camtraps a dataset of medium and large Terrestrial Mammal communities in the atlantic forest of south america
Ecology, 2017Co-Authors: Fernando Lima, Gabrielle Beca, Renata De Lara Muylaert, Clinton N Jenkins, Miriam Lucia Lages Perilli, Ana Maria De Oliveira Paschoal, Rodrigo Lima Massara, Adriano Pereira Paglia, Adriano Garcia Chiarello, Mauricio Eduardo GraipelAbstract:Our understanding of Mammal ecology has always been hindered by the difficulties of observing species in closed tropical forests. Camera trapping has become a major advance for monitoring Terrestrial Mammals in biodiversity rich ecosystems. Here we compiled one of the largest datasets of inventories of Terrestrial Mammal communities for the Neotropical region based on camera trapping studies. The dataset comprises 170 surveys of medium to large Terrestrial Mammals using camera traps conducted in 144 areas by 74 studies, covering six vegetation types of tropical and subtropical Atlantic Forest of South America (Brazil and Argentina), and present data on species composition and richness. The complete dataset comprises 53,438 independent records of 83 species of Mammals, includes 10 species of marsupials, 15 rodents, 20 carnivores, 8 ungulates and 6 armadillos. Species richness averaged 13 species (± 6.07 SD) per site. Only six species occurred in more than 50% of the sites: the domestic dog Canis familiaris, crab-eating fox Cerdocyon thous, tayra Eira barbara, south American coati Nasua nasua, crab-eating raccoon Procyon cancrivorus and the nine-banded armadillo Dasypus novemcinctus. The information contained in this dataset can be used to understand macroecological patterns of biodiversity, community, and population structure, but also to evaluate the ecological consequences of fragmentation, defaunation, and trophic interactions. This article is protected by copyright. All rights reserved.
Charlie J. Underwood - One of the best experts on this subject based on the ideXlab platform.
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A new Oligocene site with Terrestrial Mammals and a selachian fauna from Minqar Tibaghbagh, the western Desert of Egypt
2020Co-Authors: H.j.a.n. Van Vliet, Anne S. Schulp, G.a.m.m. Abu El-kheir, T.m. Paijmans, M. Bosselaers, Charlie J. UnderwoodAbstract:A new fossil site at Minqar Tibaghbagh, east of Siwa, in the Egyptian Western Desert is described. This represents the first place in Egypt outside the Fayum Depression yielding Paleogene, Terrestrial Mammals. Initial studies indicate the presence of palaeomastodonts, hyracoids, and anthracotheres, presumably early Oligocene in age. As only surface prospecting has been performed, more taxa will almost certainly be discovered in future investigations here and probably also elsewhere in the surroundings. A comparison is made with the most important contemporaneous sites in Libya and Egypt that yield Terrestrial Mammal remains. The selachian fauna from a higher level in the section confirms the Paleogene age of the subjacent strata. It is compared with selachians faunas from the early Oligocene Eastern Tethys Ocean at other places (the Fayum Depression in Egypt, and sites in Oman and Pakistan), and differs from these sites in being fully marine. Contrary to earlier studies, the open marine mudstones of the Daba’a Formation at Minqar Tibaghbagh are overlain by Paleogene marine sediments of most probably early Oligocene age and not early Miocene marine sediments as previously reported. These strata represent not only a new site with great potential for future finds, but also allows for biostratigraphic correlation.
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A new site with Oligocene Terrestrial Mammals and an Oligocene selachian fauna from Minqar Tibaghbagh, the Western Desert of Egypt
Acta Palaeontologica Polonica, 2018Co-Authors: H.j.a.n. Van Vliet, Anne S. Schulp, G.a.m.m. Abu El-kheir, T.m. Paijmans, M. Bosselaers, Charlie J. UnderwoodAbstract:A new fossil site at Minqar Tibaghbagh, east of Siwa, in the Egyptian Western Desert is described. This represents the first place in Egypt outside the Fayum Depression yielding Paleogene, Terrestrial Mammals. Initial studies indicate the presence of palaeomastodonts, hyracoids, and anthracotheres, presumably early Oligocene in age. As only surface prospecting has been performed, more taxa will almost certainly be discovered in future investigations here and probably also elsewhere in the surroundings. A comparison is made with the most important contemporaneous sites in Libya and Egypt that yield Terrestrial Mammal remains. The selachian fauna from a higher level in the section confirms the Paleogene age of the subjacent strata. It is compared with selachians faunas from the early Oligocene Eastern Tethys Ocean at other places (the Fayum Depression in Egypt, and sites in Oman and Pakistan), and differs from these sites in being fully marine. Contrary to earlier studies, the open marine mudstones of the Daba’a Formation at Minqar Tibaghbagh are overlain by Paleogene marine sediments of most probably early Oligocene age and not early Miocene marine sediments as previously reported. These strata represent not only a new site with great potential for future finds, but also allows for biostratigraphic correlation.
Raimundo Real - One of the best experts on this subject based on the ideXlab platform.
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geographical gradients in argentinean Terrestrial Mammal species richness and their environmental correlates
The Scientific World Journal, 2012Co-Authors: Ana Luz Marquez, Raimundo Real, Jose Carlos Guerrero, Betina Galvan, Marcia A Barbosa, Jesus Olivero, Javier L Palomo, Mario J Vargas, Enrique R JustoAbstract:We analysed the main geographical trends of Terrestrial Mammal species richness (SR) in Argentina, assessing how broad-scale environmental variation (defined by climatic and topographic variables) and the spatial form of the country (defined by spatial filters based on spatial eigenvector mapping (SEVM)) influence the kinds and the numbers of Mammal species along these geographical trends. We also evaluated if there are pure geographical trends not accounted for by the environmental or spatial factors. The environmental variables and spatial filters that simultaneously correlated with the geographical variables and SR were considered potential causes of the geographic trends. We performed partial correlations between SR and the geographical variables, maintaining the selected explanatory variables statistically constant, to determine if SR was fully explained by them or if a significant residual geographic pattern remained. All groups and subgroups presented a latitudinal gradient not attributable to the spatial form of the country. Most of these trends were not explained by climate. We used a variation partitioning procedure to quantify the pure geographic trend (PGT) that remained unaccounted for. The PGT was larger for latitudinal than for longitudinal gradients. This suggests that historical or purely geographical causes may also be relevant drivers of these geographical gradients in Mammal diversity.
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Using crisp and fuzzy modelling to identify favourability hotspots useful to perform gap analysis
Biodiversity and Conservation, 2008Co-Authors: Alba Estrada, Raimundo Real, J. Mario VargasAbstract:In this study, we propose the use of a favourability function to perform Gap Analysis. To exemplify this, we modelled the distribution of Terrestrial Mammal species in Andalusia (South of Spain) on the basis of their presence/absence on a grid of 10 km x 10 km UTM cells (n = 961). Using logistic regression and 30 variables related with the environment, space and human influence, we obtained probabilities of occurrence for each species in each cell. We computed a crisp favourability index considering the areas as favourable or unfavourable for a species if the probability of occurrence was higher or lower than the species prevalence, respectively. We also used a favourability function and fuzzy logic to level all species to the same threshold of favourability, which allowed to compare and to combine species distributions. Adding up the fuzzy favourability values for each species in each cell we obtained a fuzzy favourability index that we compared with species richness (sum of species in each cell) and with the crisp favourability index. We performed Gap Analysis by overlapping these results with the current reserve network of Andalusia. Gaps were grouped in fewer and bigger zones after applying the favourability indices. Considerations and recommendations for the use of the favourability function to select areas of conservation interest are discussed
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relative importance of environment human activity and spatial situation in determining the distribution of Terrestrial Mammal diversity in argentina
Journal of Biogeography, 2003Co-Authors: Raimundo Real, Ana Luz Marquez, Jose Carlos Guerrero, Marcia A Barbosa, Javier L Palomo, Enrique R Justo, Daniela Porras, Mario J VargasAbstract:Aim The partition of the geographical variation in Argentinian Terrestrial Mammal species richness (SR) into environmentally, human and spatially induced variation. Location Argentina, using the twenty-three administrative provinces as the geographical units. Methods We recorded the number of Terrestrial Mammal species in each Argentinian province, and the number of species belonging to particular groups (Marsupialia, Placentaria, and among the latter, Xenarthra, Carnivora, Ungulates and Rodentia). We performed multiple regressions of each group’s SR on environmental, human and spatial variables, to determine the amounts of variation explained by these factors. We then used a variance partitioning procedure to specify which proportion of the variation in SR is explained by each of the three factors exclusively and which proportions are attributable to interactions between factors. Results For marsupials, human activity explains the greatest part of the variation in SR. The purely environmental and purely human influences on all Mammal SR explain a similarly high proportion of the variation in SR, whereas the purely spatial influence accounts for a smaller proportion of it. The exclusive interaction between human activity and space is negative in carnivores and rodents. For rodents, the interaction between environment and spatial situation is also negative. In the remaining placental groups, pure spatial autocorrelation explains a small proportion of the variation in SR. Main conclusions Environmental factors explain most of the variation in placental SR, while Marsupials seem to be mainly affected by human activity. However, for edentates, carnivores, and ungulates the pure human influence is more important than the pure spatial and environmental influences. Besides, human activity disrupts the spatial structure caused by the history and population dynamics of rodents and, to a lesser extent, of carnivores. The historical events and population dynamics on the one hand, and the environment on the other, cause rodent SR to vary in divergent directions. In the remaining placental groups the autocorrelation in SR is mainly the result of autocorrelation in the environmental and human variables.
Mario J Vargas - One of the best experts on this subject based on the ideXlab platform.
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geographical gradients in argentinean Terrestrial Mammal species richness and their environmental correlates
The Scientific World Journal, 2012Co-Authors: Ana Luz Marquez, Raimundo Real, Jose Carlos Guerrero, Betina Galvan, Marcia A Barbosa, Jesus Olivero, Javier L Palomo, Mario J Vargas, Enrique R JustoAbstract:We analysed the main geographical trends of Terrestrial Mammal species richness (SR) in Argentina, assessing how broad-scale environmental variation (defined by climatic and topographic variables) and the spatial form of the country (defined by spatial filters based on spatial eigenvector mapping (SEVM)) influence the kinds and the numbers of Mammal species along these geographical trends. We also evaluated if there are pure geographical trends not accounted for by the environmental or spatial factors. The environmental variables and spatial filters that simultaneously correlated with the geographical variables and SR were considered potential causes of the geographic trends. We performed partial correlations between SR and the geographical variables, maintaining the selected explanatory variables statistically constant, to determine if SR was fully explained by them or if a significant residual geographic pattern remained. All groups and subgroups presented a latitudinal gradient not attributable to the spatial form of the country. Most of these trends were not explained by climate. We used a variation partitioning procedure to quantify the pure geographic trend (PGT) that remained unaccounted for. The PGT was larger for latitudinal than for longitudinal gradients. This suggests that historical or purely geographical causes may also be relevant drivers of these geographical gradients in Mammal diversity.
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relative importance of environment human activity and spatial situation in determining the distribution of Terrestrial Mammal diversity in argentina
Journal of Biogeography, 2003Co-Authors: Raimundo Real, Ana Luz Marquez, Jose Carlos Guerrero, Marcia A Barbosa, Javier L Palomo, Enrique R Justo, Daniela Porras, Mario J VargasAbstract:Aim The partition of the geographical variation in Argentinian Terrestrial Mammal species richness (SR) into environmentally, human and spatially induced variation. Location Argentina, using the twenty-three administrative provinces as the geographical units. Methods We recorded the number of Terrestrial Mammal species in each Argentinian province, and the number of species belonging to particular groups (Marsupialia, Placentaria, and among the latter, Xenarthra, Carnivora, Ungulates and Rodentia). We performed multiple regressions of each group’s SR on environmental, human and spatial variables, to determine the amounts of variation explained by these factors. We then used a variance partitioning procedure to specify which proportion of the variation in SR is explained by each of the three factors exclusively and which proportions are attributable to interactions between factors. Results For marsupials, human activity explains the greatest part of the variation in SR. The purely environmental and purely human influences on all Mammal SR explain a similarly high proportion of the variation in SR, whereas the purely spatial influence accounts for a smaller proportion of it. The exclusive interaction between human activity and space is negative in carnivores and rodents. For rodents, the interaction between environment and spatial situation is also negative. In the remaining placental groups, pure spatial autocorrelation explains a small proportion of the variation in SR. Main conclusions Environmental factors explain most of the variation in placental SR, while Marsupials seem to be mainly affected by human activity. However, for edentates, carnivores, and ungulates the pure human influence is more important than the pure spatial and environmental influences. Besides, human activity disrupts the spatial structure caused by the history and population dynamics of rodents and, to a lesser extent, of carnivores. The historical events and population dynamics on the one hand, and the environment on the other, cause rodent SR to vary in divergent directions. In the remaining placental groups the autocorrelation in SR is mainly the result of autocorrelation in the environmental and human variables.
