32 research outputs found

    Criterios biológicos y ecológicos: aportes para la identificación, caracterización y delimitación de los humedales interiores de Colombia.

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    Este producto es elaborado por el Programa Biología de la Conservación y Uso de la Biodiversidad en el marco del convenio 005 (13-014) entre el Instituto Humboldt y el Fondo Adaptación, en este documento se asume los principios generales de los ecosistemas, en los que se caracterizan como sistemas complejos, abiertos, dinámicos e integrados en donde los patrones ecológicas y la diversidad biológica son el resultado de un proceso biogeográfico que a su vez es afectado por procesos antrópicos. Es por ello que los ecosistemas de humedales de interior son considerados unidades funcionales en los que son necesarias las conexiones de la transición de hábitats en función de la pendiente natural (cuenca aguas arriba y abajo), hacia los ecosistemas adyacentes terrestres y dentro del cuerpo de agua (entre las zonas someras y profundas).Bogotá, ColombiaPrograma Biología de la Conservación y Uso de la Biodiversida

    High Levels of Diversity Uncovered in a Widespread Nominal Taxon: Continental Phylogeography of the Neotropical Tree Frog

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    Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered

    ALTERNATING CURRENT MAGNETIC SUSCEPTIBILITY MEASUREMENTS IN La1-xSrxCoO3 (x≤0.3) below 300 K

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