Papers by Oswaldo Tellez-Valdes
Capital natural de México vol I: Conocimiento actual de la biodiversidad, 2008
3 4 5 6 7 8 9 10 ... 28 29 30 31 32 33 34 35 36 37 38 39 40 41 ... Autores por orden alfabético: ... more 3 4 5 6 7 8 9 10 ... 28 29 30 31 32 33 34 35 36 37 38 39 40 41 ... Autores por orden alfabético: Héctor Arita3, Patricia Dávila4, Oscar Flores-Villela5, Gonzalo Halffter6, Andrés Lira-Noriega1, Claudia E. Moreno7, Elizabeth Moreno1, Mariana Munguía8, Miguel Murguía4, Adolfo G. Navarro-Sigüenza5, Oswaldo Téllez4, Leticia Ochoa-Ochoa5, A. Townsend Peterson2, Pilar Rodríguez9 ... 1. DISTRIBUCION ESPACIAL DE LAS ESPECIES DE PECES ... Autores: Salvador Contreras-Balderas10, Roberto Mendoza Alfaro11 y Carlos ...
Journal of Thermal Biology, Aug 1, 2023
Ecology and Evolution
Tropical ectotherm species tend to have narrower physiological limits than species from temperate... more Tropical ectotherm species tend to have narrower physiological limits than species from temperate areas. As a consequence, tropical species are considered highly vulnerable to climate change since minor temperature increases can push them beyond their physiological thermal tolerance. Differences in physiological tolerances can also be seen at finer evolutionary scales, such as among populations of ectotherm species along elevation gradients, highlighting the physiological sensitivity of such organisms. Here, we analyze the influence of elevation and bioclimatic domains, defined by temperature and precipitation, on thermal sensitivities of a terrestrial direct‐developing frog (Craugastor loki) in a tropical gradient. We address the following questions: (a) Does preferred temperature vary with elevation and among bioclimatic domains? (b) Do thermal tolerance limits, that is, critical thermal maximum and critical thermal minimum vary with elevation and bioclimatic domains? and (c) Are ...
Revista Mexicana de Biodiversidad
Composition, structure and diversity of tree and shrub strata in a tropical deciduous forest at T... more Composition, structure and diversity of tree and shrub strata in a tropical deciduous forest at Tehuacán Valley, Mexico Composición, estructura y diversidad de los estratos arbóreo y arbustivo en un bosque tropical caducifolio en el valle de Tehuacán, México
Revista Mexicana de Biodiversidad
We apply an environmental domains approach to identify environmentally heterogeneous characterist... more We apply an environmental domains approach to identify environmentally heterogeneous characteristics defining a landscape matrix. We built environmental layers for national, regional, and local scales, considering the different scales studies can have. We used a numerical classification of explicit spatial layers and performed a multivariate classification. Based on the domains obtained, we mapped the landscape’s climatic heterogeneity and identified a comprehensive set of environmental variables that defined the landscape matrix at each scale. We specifically tested our approach for its suitability to define a sampling strategy for a landscape genetics study, using as focal species the rodent Heteromys pictus. Namely, from the domains obtained at the local scale, we selected sampling localities that comprised the broadest habitat heterogeneity, which we corroborated in the field. The landscape matrix thus generated was used with genetic data previously obtained for H. pictus. Our a...
The Holocene, 2021
Seasonal dry tropical forest (STDF) is a widespread vegetation type in western Mexico. Generally,... more Seasonal dry tropical forest (STDF) is a widespread vegetation type in western Mexico. Generally, this type of forest develops in semihumid habitats where lacustrine basins are scarce, preventing documentation of the vegetation history and forest dynamics using a paleoecological approach. Here, we present a palynological record from the Santa Maria del Oro crater lake, located within the distribution area of the STDF and the adjacent dry oak forest which gives insight into the changes in diversity and human impact at this tropical site. Pollen data, in combination with geochemical analysis and microcharcoal data from a lacustrine sequence, are used to discuss vegetation change and diversity in the plant assemblages related to drought or anthropogenic activity over the last 5000 years. Our results show three distinct periods of drought in the basin, from 4200 to 3850, 3100 to 2300, 1570 to 1100 and 300 cal year BP, with changes in vegetation composition mainly related to a decrease i...
Novon, A Journal for Botanical Nomenclature, 2022
Dioscorea sinaloensis O. Téllez (Dioscoreaceae) is described and illustrated. It is known from th... more Dioscorea sinaloensis O. Téllez (Dioscoreaceae) is described and illustrated. It is known from the type locality, in the municipality of Concordia, Sinaloa, Mexico. According to Knuth’s classification of 1924, it belongs to section Apodostemon Uline. However, in a recent phylogenetic study, this section is resolved as a polyphyletic group, related to species of other “sections” like Heterostemon Uline, Macrogynodium Uline, or Strutantha Uline or to other morphologically different species. Dioscorea sinaloensis can be confused with D. gallegosi Matuda, D. gomez-pompae O. Téllez, D. megaphylla Ram.-Amezcua, O. Téllez & V. W. Steinm., D. mexicana Scheidw., and D. subtomentosa Miranda, but is clearly distinct.
Revista Fitotecnia Mexicana, 2017
Mammillaria agrupa a 200 especies, 164 registradas en México, 85 % son endémicas y 113 están en l... more Mammillaria agrupa a 200 especies, 164 registradas en México, 85 % son endémicas y 113 están en la Norma Oficial Mexicana NOM-059 SEMARNAT-2010. A pesar de su importancia en la biodiversidad y de su grave crisis de conservación, la escasa información documentada en estas especies no permite proponer estrategias para protegerlas. Nuestro objetivo fue estimar los niveles de diversidad genética poblacional en M. hernandezii, M. kraehenbuehlii y M. napina para identificar unidades genéticas de conservación. Se genotiparon con 10 loci de microsatélites 24 individuos de dos poblaciones de M. hernandezii y 120 individuos de cinco poblaciones para cada una de las otras dos especies. En las tres especies se estimaron niveles de heterocigosidad observada menores que los esperados (M. hernandezii 0.58, 0.65; M. kraehenbuehlii 0.61, 0.73; y M. napina 0.56, 0.74), la diversidad alélica varió de cinco (M. hernandezii) a ocho alelos en las otras dos especies. Las tres especies mostraron una defici...
Brittonia, 2019
A new species, Dioscorea chusqueifolia (Dioscoreaceae), is described and illustrated. It is known... more A new species, Dioscorea chusqueifolia (Dioscoreaceae), is described and illustrated. It is known only from two nearby localities in the Province of Bolívar (Department of La Libertad) in northern Peru, where it grows in the transitional zone between equatorial dry forest and montane forest at 700-900 m elevation. The new species is distinguished by a unique combination of features, such as the form and size of its leaves (narrowly lanceolate and 0.15-1.9 cm wide), the presence of six stamens, the absence of a pistilodium, a reduced stylar column, terete styles, and peripherally winged seeds; because of this unique set of characters, D. chusquefolia cannot be placed within any of the currently recognized sections within Dioscorea.
Genetic Resources and Crop Evolution, 2017
In the Tehuacán-Cuicatlán Valley (TCV) a total of 1605 useful plant species have been recorded. A... more In the Tehuacán-Cuicatlán Valley (TCV) a total of 1605 useful plant species have been recorded. All of them, anthropologically speaking, are very important and thus, it is worthy to explore various options for ensuring their conservation. Accordingly, the aim of this work was focused in identifying potential areas for the conservation of useful plant species of the TCV. For doing so, we compared two databases from the TCV. The known and potential distributions were identified for 272 species, using MaxEnt. The distribution data was intersected with a grid of 153 operative geographic units (OGUs) that were used to elaborate the species presence matrixes. An optimization algorithm was applied for both the known and the potential distribution and their respective species accumulation curves were compared. A list of 583 useful plant species of the TCV was obtained. These species are heterogeneously distributed in 111 of the 153 recorded OGUs. Ten families contribute with 55.06% of the overall plant richness of the TCV. In addition, the analysis revealed that at least, 13 OGUs are needed to conserve 81% of the useful flora, which represents approximately 30% of the flora, in only 8.5% of the total TCV surface. The selected sites coincide with those areas where some incipient domestication processes, as well as, plant endemism and richness centers have been reported.
Revista Mexicana de Biodiversidad, 2016
Se documentó la presencia de águila real (Aquila chrysaetos) mediante el fotorregistro más sureño... more Se documentó la presencia de águila real (Aquila chrysaetos) mediante el fotorregistro más sureño del estado de Puebla en la Reserva de la Biosfera Tehuacán-Cuicatlán. La selva baja caducifolia y el matorral xerófilo de la reserva son tipos de vegetación con condiciones ambientales favorables para la presencia del águila real y se propone que se considere a la Reserva de la Biosfera Tehuacán-Cuicatlán como área de distribución de la rapaz. Se sugiere que se capacite a los comités de vigilancia de las comunidades rurales para reconocer y registrar avistamientos, lo que permitiría obtener la información para determinar si las águilas habitan en la reserva durante todo el año o durante su migración. Derechos Reservados © 2016 Universidad Nacional Autónoma de México, Instituto de Biología. Este es un artículo de acceso abierto distribuido bajo los términos de la Licencia Creative Commons CC BY-NC-ND 4.0.
Journal for Nature Conservation, 2016
We modeled the potential distribution of plant species that grow on the beaches and dunes of the ... more We modeled the potential distribution of plant species that grow on the beaches and dunes of the Mexican Atlantic coast in order to identify areas of high biodiversity. We used environmental layers in combination with georeferenced data, utilizing the MaxEnt algorithm, and produced four regional consensus maps according to the geographic distribution of the species: along the entire Mexican Atlantic coast, the Gulf of Mexico; the Yucatan Peninsula and all species combined together on a single map. The largest number of widely distributed species in the Gulf of Mexico was concentrated in the northern and central regions, while biodiversity on the Yucatan Peninsula was likely to be concentrated in the north and on Cozumel island, which is the biggest island in the Mexican Caribbean. The map combining all species together revealed a potential concurrence of species in the Gulf of Mexico and Yucatan Peninsula transition, where climatic characteristics converge within a small geographic area. In order to conserve beach and coastal dune plant biodiversity, special attention must be paid to the management plans of established protected areas and to the promotion of new protected areas consistent with the areas reported in this study, particularly in the central Gulf of Mexico and northern Yucatan Peninsula, where areas under protection are currently scarce.
Polibotanica, 2014
The Volcanic Belt of Mexico is located in the overlapping area of the Nearctic and Neotropical re... more The Volcanic Belt of Mexico is located in the overlapping area of the Nearctic and Neotropical regions, which makes it the territory with the highest biological richness in Mexico. Based on the diverse fl ora (4 055 species of seed plants) of this area, as well as its vegetation types and climate variation, network scenarios are delimited to defi ne priority areas for conservation. By means of complementarity metaheuristics analyses and considering three representation percentages (5%, 10% and 25%) of biological and environmental attributes, nine scenarios are described as a basis to defi ne conservation areas in central Mexico. Those defi ned scenarios are compared with the Protected Areas and Priority Terrestrial Agosto 2014 Núm. 38: 193-212 Regions already existing in the Volcanic Belt area of Mexico. We found that some areas with a high biological richness are not yet included in any of the conservation areas, a fact that suggests the need to reassess the role that these areas play in protecting biodiversity in a medium and long term.
Anales Del Instituto De Biologia Unam Serie Botanica, 1992
El Eje Volcanico Transversal es una provincia caracterizada por rasgos geomorficos, geologicos y ... more El Eje Volcanico Transversal es una provincia caracterizada por rasgos geomorficos, geologicos y bioticos, muy particulares, algunos de los cuales determinan su variabilidad climatica. Datos promedio mensuales de temperatura minima y maxima y precipitacion fueron interpolados con el paquete ANUSPLIN a una resolucion espacial de 1 km2. Los datos de 19 parametros bioclimaticos y tres de terreno (pendiente, orientacion y elevacion) fueron clasificados con la metrica de Gower. Con la clasificacion obtenida se definieron regionalizaciones a distintas escalas, se muestran ejemplos a nivel de dos, diez y cincuenta dominios climaticos. Se construyo un fenograma usando UPGMA. Se identificaron distintas regiones con base en las clasificaciones referidas. A diferentes escalas se proponen dos, cuatro y nueve regiones climaticas para el Eje Volcanico Transversal. Con los dominios generados se hizo un analisis de la climatologia que puede emplearse como sustituto de la biodiversidad en las Areas Naturales protegidas.
Phytochemistry, 1983
Abstract From the roots of Tephrosia woodii , a new Mexican Tephrosia species, a new prenylated f... more Abstract From the roots of Tephrosia woodii , a new Mexican Tephrosia species, a new prenylated flavanone, oaxacacin, and its chalcone, mixtecacin, have been isolated and their structures elucidated from their chemical properties and spectral data.
Botanical Sciences
Twenty-one years have elapsed of the 21st Century and within the framework of the celebration of ... more Twenty-one years have elapsed of the 21st Century and within the framework of the celebration of the 100th volume of Botanical Sciences , it is relevant to assess the progress of the research on conservation and on the activities undertaken for protecting the plants of Mexico, including the complementary in situ and ex situ approaches. By means of a systematic search of scientific articles related to the conservation of the Mexican flora on the Web of Science database, for the 2000–2021 period, we identified different scientific inputs, all showing specific objectives for undertaking conservation activities. The publications that resulted from this search were classified into six categories: (a) Regions and Ecoregions; (b) Communities or Ecosystems; (c) Taxonomic Groups; (d) Species and Populations; (e) Botanical Gardens; and (f) Seed Banks. For these categories, the results are presented under the headings “ in situ conservation” and “ ex situ conservation.” Additionally, we assess...
PLOS ONE, Jul 16, 2020
Spatial assessments of historical climate change provide information that can be used by scientis... more 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 20 th and early 21 st centuries:
Australian Systematic Botany, 2023
Fabaceae is a monophyletic family comprising more than 22 000 species worldwide. In Mexico, it is... more Fabaceae is a monophyletic family comprising more than 22 000 species worldwide. In Mexico, it is the second-most species rich family, inhabiting multiple ecosystems with a high diversity of life forms. Our aims were to (1) identify areas of endemism (AEs) by using endemicity analysis at different cell sizes (1°, 0.5° and 0.25°) for 488 Mexican legumes, (2) describe the climatic and topographic heterogeneity of AE, (3) determine whether there is a positive relationship between AEs and climatic and topographic heterogeneity and (4) examine the conservation status of legumes that defined the AEs. We found six general AEs, supported by 63 species, with endemicity index values ranging from 2.05 to 6.86. These general areas had zones where biogeographical provinces intersected and exhibited a higher environmental heterogeneity. Areas detected at 1° showed a positive relationship between endemicity index and environmental heterogeneity. Legume species currently lack legal protection in Mexico, 69% of the endemic species do not have an evaluation category according to the International Union for Conservation of Nature, and eight species are in some risk category. Future conservation efforts should focus on protecting endemism areas from accomplishing representative natural protected areas.
Uploads
Papers by Oswaldo Tellez-Valdes