11 research outputs found

    Twentieth century turnover of Mexican endemic avifaunas: Landscape change versus climate drivers

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    Numerous climate change effects on biodiversity have been anticipated and documented, including extinctions, range shifts, phenological shifts, and breakdown of interactions in ecological communities, yet the relative balance of different climate drivers and their relationships to other agents of global change (for example, land use and land-use change) remains relatively poorly understood. This study integrated historical and current biodiversity data on distributions of 115 Mexican endemic bird species to document areas of concentrated gains and losses of species in local communities, and then related those changes to climate and land-use drivers. Of all drivers examined, at this relatively coarse spatial resolution, only temperature change had significant impacts on avifaunal turnover; neither precipitation change nor human impact on landscapes had detectable effects. This study, conducted across species’ geographic distributions, and covering all of Mexico, thanks to two large-scale biodiversity data sets, could discern relative importance of specific climatic drivers of biodiversity change

    Evaluation of animal and plant diversity suggests Greenland’s thaw hastens the biodiversity crisis

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    Rising temperatures can lead to the occurrence of a large-scale climatic event, such as the melting of Greenland ice sheet, weakening the AMOC and further increasing dissimilarities between current and future climate. The impacts of such an event are still poorly assessed. Here, we evaluate those impacts across megadiverse countries on 21,146 species of tetrapods and vascular plants using the pessimistic climate change scenario (RCP 8.5) and four different scenarios of Greenland’s ice sheet melting. We show that RCP 8.5 emission scenario would lead to a widespread reduction in species’ geographic ranges (28–48%), which is projected to be magnified (58–99%) with any added contribution from the melting of Greenland. Also, declines in the potential geographical extent of species hotspots (12–89%) and alterations of species composition (19–91%) will be intensified. These results imply that the influence of a strong and rapid Greenland ice sheet melting, resulting in a large AMOC weakening, can lead to a faster collapse of biodiversity across the globe

    Curso modelado de nicho ecológico, version 1.0

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    The suite of ideas, protocols, and software tools that has come to be known as “Ecological Niche Modeling” (ENM) — as well as those for the related “Species Distribution Modeling” (SDM)—has seen intensive exploration and research attention in recent decades. In spite of at least four syntheses, the field has grown so much in complexity that it is rather difficult to access for newcomers. Until now, accessibility to this field was achieved by in-person courses organized by universities or research centers, in some of which we have participated as instructors. However, the access to these specialized courses is limited, on one hand because they are not offered in all universities, and on the other because normally they are taught in English. To expand the access to a wider community of Spanish-speaking researchers, here we offer an entirely digital and free-of-charge course in Spanish, which was presented over 23 weeks via Internet in 2018. Although intrinsic Internet-related barriers may limit access to course materials, we have made them available in diverse formats (video, audio, pdf) in order to eliminate most of these problems.El conjunto de ideas, métodos y programas informáticos que se conoce como “Modelado de Nicho Ecológico” (MNE)—y el relacionado “Modelado de Distribución de Especies” (MDS)—han sido objeto de intensa exploración e investigación en las últimas décadas. A pesar de existir al menos cuatro síntesis publicadas, este campo ha crecido tanto en complejidad, que la formación de nuevos investigadores es difícil. Hasta ahora, dicha formación se ha hecho de manera presencial en cursos organizados por universidades o centros de investigación, de los que hemos formado parte como instructores. Sin embargo, el acceso a este tipo de cursos especializados es restringido, por un lado, porque los cursos no se ofrecen en todas las universidades, y por otro, porque normalmente se imparten en inglés. Para facilitar el acceso a una mayor comunidad de científicos de habla hispana, presentamos un curso en español, completamente digital y de acceso gratuito, que se realizó vía Internet durante 23 semanas consecutivas en 2018. Aunque las barreras intrínsecas al uso de Internet pueden dificultar la accesibilidad a los materiales del curso, hemos usado diversos formatos para la divulgación de los contenidos académicos (video, audio, pdf) con el objetivo de eliminar la mayor parte de estos problemas

    Distribución potencial del jaguar Panthera onca (Carnivora: Felidae) en Guerrero, México: persistencia de zonas para su conservación

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    Studies about the permanence of natural protected areas are important, because they contribute to the promotion of the conservation target and to optimize economical and human resources of specific areas. Although there are no natural protected areas in Guerrero, it has suitable habitat for the jaguar, a common species used for planning and management of conservation areas. Since, there is actual evidence that environmental and anthropogenic variables may modify vertebrate species distribution with time, in this study we predicted the potential distribution of Panthera onca using MaxEnt for this Southeastern region. In addition, we made a projection considering the effect of a moderate climate change scenario, to evaluate the stability of the conservation area for a period of 24 years. Furthermore, we applied three threat scenarios for the actual prediction to define conservation priorities areas. In our results, we have found that 18 361Km2 (29%) of this state has a permanent suitable habitat for jaguar conservation in the Sierra Madre del Sur and Pacific coast, with a possible loss of 2 000km2 in 24 years. This habitat is characterized by a 56% of temperate forest (mainly conifers and hardwoods 34%), and 35% of tropical deciduous forest. With the projections, the Southeastern region resulted with the higher anthropogenic impacts, while at the same time, an area of 7 900km2 in the Central-Western state was determined as a priority for conservation. To assure jaguar conservation, we propose the inclusion of this new conservation area, which is located in the Sierra Madre del Sur, with which we may potentially preserve other 250 species of threatened vertebrates. This way, the suggested habitat conservation may represent a local effort in Guerrero and will strengthen the biological corridor network for P. onca protection in Latin America

    Distribución potencial del jaguar Panthera onca (Carnivora: Felidae) en Guerrero, México: persistencia de zonas para su conservación

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    "Guerrero se caracteriza por presentar extensiones considerables y adecuadas de hábitat para el jaguar, pero carece de áreas naturales protegidas. Son importantes los estudios sobre la persistencia de las áreas naturales protegidas debido a que ofrecen e

    Distribución potencial del jaguar Panthera onca (Carnivora: Felidae) en Guerrero, México: persistencia de zonas para su conservación Potential distribution of jaguar, Panthera onca (Carnivora: Felidae) in Guerrero, Mexico: per- sistence of areas for its conservation

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    Studies about the permanence of natural protected areas are important, because they contribute to the promotion of the conservation target and to optimize economical and human resources of specific areas. Although there are no natural protected areas in Guerrero, it has suitable habitat for the jaguar, a common species used for planning and management of conservation areas. Since, there is actual evidence that environmental and anthropogenic variables may modify vertebrate species distribution with time, in this study we predicted the potential distribution of Panthera onca using MaxEnt for this Southeastern region. In addition, we made a projection considering the effect of a moderate climate change scenario, to evaluate the stability of the conservation area for a period of 24 years. Furthermore, we applied three threat scenarios for the actual prediction to define conservation priorities areas. In our results, we have found that 18 361Km2 (29%) of this state has a permanent suitable habitat for jaguar conservation in the Sierra Madre del Sur and Pacific coast, with a possible loss of 2 000km2 in 24 years. This habitat is characterized by a 56% of temperate forest (mainly conifers and hardwoods 34%), and 35% of tropical deciduous forest. With the projections, the Southeastern region resulted with the higher anthropogenic impacts, while at the same time, an area of 7 900km2 in the Central-Western state was determined as a priority for conservation. To assure jaguar conservation, we propose the inclusion of this new conservation area, which is located in the Sierra Madre del Sur, with which we may potentially preserve other 250 species of threatened vertebrates. This way, the suggested habitat conservation may represent a local effort in Guerrero and will strengthen the biological corridor network for P. onca protection in Latin America

    One hundred years of climate change in Mexico.

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    Spatial assessments of historical climate change provide information that can be used by scientists to analyze climate variation over time and evaluate, for example, its effects on biodiversity, in order to focus their research and conservation efforts. Despite the fact that there are global climatic databases available at high spatial resolution, they represent a short temporal window that impedes evaluating historical changes of climate and their impacts on biodiversity. To fill this gap, we developed climate gridded surfaces for Mexico for three periods that cover most of the 20th and early 21st centuries: t1-1940 (1910-1949), t2-1970 (1950-1979) and t3-2000 (1980-2009), and used these interpolated surfaces to describe how climate has changed over time, both countrywide and in its 19 biogeographic provinces. Results from our characterization of climate change indicate that the mean annual temperature has increased by nearly 0.2°C on average across the whole country from t2-1970 to t3-2000. However, changes have not been spatially uniform: Nearctic provinces in the north have suffered higher temperature increases than southern tropical regions. Central and southern provinces cooled at the beginning of the 20th century but warmed consistently since the 1970s. Precipitation increased between t1-1940 and t2-1970 across the country, more notably in the northern provinces, and it decreased between t2-1970 and t3-2000 in most of the country. Results on the historical climate conditions in Mexico may be useful for climate change analyses for both environmental and social sciences. Nonetheless, our climatology was based on information from climate stations for which 9.4-36.2% presented inhomogeneities over time probably owing to non-climatic factors, and climate station density changed over time. Therefore, the estimated changes observed in our analysis need to be interpreted cautiously

    Storage of organic carbon in the soils of Mexican temperate forests

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    The deforestation and degradation of natural habitats is the second largest contributor to carbon dioxide (CO2) emissions to the atmosphere. Temperate forests cover ∼16.5% of the Mexican landscape, and are a priority ecosystem for global conservation due to their high rate of endemism and species diversity. These forests also provide valuable ecosystem services, including the storage of organic carbon. Mexican temperate forests have lost more than half of their original cover, with ongoing forest degradation, resulting in CO2 emissions to the atmosphere. Most studies and carbon inventories only consider organic carbon stored in the aboveground biomass, and do not consider the organic carbon stored within soils of temperate forests. As a result, the emissions of CO2 due to deforestation are underestimated, and the value of temperate forests is underappreciated. To address this shortcoming, (1) we examine the extent and factors determining soil organic carbon stocks; (2) we estimate soil organic carbon stocks of Mexican temperate forests, the CO2 emissions caused by deforestation and avoided emissions from conservation and (3) we discuss the causes of loss of soil OC and management strategies to mitigate this loss. We propose that including the soil organic carbon stock-component is a priority for national projects targeting reducing emissions from deforestation. Also, urgent studies on the impacts of forest degradation in stocks of soil organic carbon are needed. Management strategies for conservation and rehabilitation of Mexican temperate forests must consider social and economic aspects of the local communities

    Ecological Niche Modeling Course, Version 1.0

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    This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.The suite of ideas, protocols, and software tools that has come to be known as “Ecological Niche Modeling” (ENM) — as well as those for the related “Species Distribution Modeling” (SDM)—has seen intensive exploration and research attention in recent decades. In spite of at least four syntheses, the field has grown so much in complexity that it is rather difficult to access for newcomers. Until now, accessibility to this field was achieved by in-person courses organized by universities or research centers, in some of which we have participated as instructors. However, the access to these specialized courses is limited, on one hand because they are not offered in all universities, and on the other because normally they are taught in English. To expand the access to a wider community of Spanish-speaking researchers, here we offer an entirely digital and free-of-charge course in Spanish, which was presented over 23 weeks via Internet in 2018. Although intrinsic Internet-related barriers may limit access to course materials, we have made them available in diverse formats (video, audio, pdf) in order to eliminate most of these problems

    Curso de Modelado de Nicho Ecológico, versión 1.0.

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    [ES] El conjunto de ideas, métodos y programas informáticos que se conoce como “Modelado de Nicho Ecológico” (MNE) el relacionado “Modelado de Distribución de Especies” (MDS)— han sido objeto de intensa exploración e investigación en las últimas décadas. A pesar de existir al menos cuatro síntesis publicadas, este campo ha crecido tanto en complejidad, que la formación de nuevos investigadores es difícil. Hasta ahora, dicha formación se ha hecho de manera presencial en cursos organizados por universidades o centros de investigación, de los que hemos formado parte como instructores. Sin embargo, el acceso a este tipo de cursos especializados es restringido, por un lado, porque los cursos no se ofrecen en todas las universidades, y por otro, porque normalmente se imparten en inglés. Para facilitar el acceso a una mayor comunidad de científicos de habla hispana, presentamos un curso en español, completamente digital y de acceso gratuito, que se realizó vía Internet durante 23 semanas consecutivas en 2018. Aunque las barreras intrínsecas al uso de Internet pueden dificultar la accesibilidad a los materiales del curso, hemos usado diversos formatos para la divulgación de los contenidos académicos (video, audio, pdf) con el objetivo de eliminar la mayor parte de estos problemas.[EN] The suite of ideas, protocols, and software tools that has come to be known as “Ecological Niche Modeling” (ENM)—as well as those for the related “Species Distribution Modeling” (SDM)—has seen intensive exploration and research attention in recent decades. In spite of at least four syntheses, the field has grown so much in complexity that it is rather difficult to access for newcomers. Until now, accessibility to this field was achieved by in-person courses organized by universities or research centers, in some of which we have participated as instructors. However, the access to these specialized courses is limited, on one hand because they are not offered in all universities, and on the other because normally they are taught in English. To expand the access to a wider community of Spanish-speaking researchers, here we offer an entirely digital and free-of-charge course in Spanish, which was presented over 23 weeks via Internet in 2018. Although intrinsic Internet-related barriers may limit access to course materials, we have made them available in diverse formats (video, audio, pdf) in order to eliminate most of these problemsLas presentes contribuciones representan difusión científica por parte de varias instituciones y agencias de financiamiento (incluyendo U.S. NSF DBI-1661510 para R.P. Anderson y Virginia Tech Startup Funds para L.E. Escobar)
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