Luis Maciel Perez | INIFAP (original) (raw)
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Papers by Luis Maciel Perez
REVISTA MEXICANA …
RESUMEN El objetivo del estudio fue conocer las características socioeconómicas de los productore... more RESUMEN El objetivo del estudio fue conocer las características socioeconómicas de los productores de tres municipios con agricultura de riego en Aguascalientes, y su actitud hacia riesgos de inversión y de mercado. La información se obtuvo por medio de ...
Investigacion Y Ciencia, 2010
* Las fotografías que se presentan son propiedad del autor y fueron tomadas durante el trabajo de... more * Las fotografías que se presentan son propiedad del autor y fueron tomadas durante el trabajo de campo.
Investigación y …, 2009
... de manifestar, de esta manera, estabilidad en el rendimiento a través del tiempo, lo cual con... more ... de manifestar, de esta manera, estabilidad en el rendimiento a través del tiempo, lo cual concuerda con lo repor-tado por Muñoz (1973) y ... para rendimiento económico y número de dientes por bulbo promedio en los clo-nes avanzados más sobresalientes de ajo Perla y testigo ...
Ecological Modelling, 2009
The greatest concentration of oak species in the world is believed to be found in Mexico. These s... more The greatest concentration of oak species in the world is believed to be found in Mexico. These species are potentially useful for reforestation because of their capacity to adapt to diverse environments. Knowledge of their geographic distribution and of species-environment relations is essential for decision-making in the management and conservation of natural resources. The objectives of this study were to develop a model of the distribution of Quercus emoryi Torr. in Mexico, using geographic information systems and data layers of climatic and other variables, and to determine the variables that significantly influence the distribution of the species. The study consisted of the following steps: (A) selection of the target species from a botanical scientific collection, (B) characterization of the collecting sites using images with values or categories of the variables, (C) model building with the overlay of images that meet the habitat conditions determined from the characterization of sites, (D) model validation with independent data in order to determine the precision of the model, (E) model calibration through adjustment of the intervals of some variables, and (F) sensitivity analysis using precision and concordance non-parametric statistics applied to pairs of images. Results show that the intervals of the variables that best describe the species' habitat are the following: altitude from 1650 to 2750 amsl, slope from 0 to 66 • ; average minimum temperature of January from −12 to −3 • C; mean temperature of June from 11 to 25 • C; mean annual precipitation from 218 to 1225 mm; soil units: lithosol, eutric cambisol, haplic phaeozem, chromic luvisol, rendzina, luvic xerosol, mollic planosol, pellic vertisol, eutric regosol; type of vegetation: oak forest, oak-pine forest, pine forest, pine-oak forest, juniperus forest, low open forest, natural grassland and chaparral. The resulting model of the geographic distribution of Quercus emoryi in Mexico had the following values for nonparametric statistics of precision and agreement: Kappa index of 0.613 and 0.788, overall accuracy of 0.806 and 0.894, sensitivity of 0.650 and 0.825, specificity of 0.963, positive predictive value of 0.945 and 0.957 and negative predictive value of 0.733 and 0.846. Results indicate that the variable average minimum temperature of January, with a maximum value of −3 • C, is an important factor in limiting the species' distribution.
REVISTA MEXICANA …
RESUMEN El objetivo del estudio fue conocer las características socioeconómicas de los productore... more RESUMEN El objetivo del estudio fue conocer las características socioeconómicas de los productores de tres municipios con agricultura de riego en Aguascalientes, y su actitud hacia riesgos de inversión y de mercado. La información se obtuvo por medio de ...
Investigacion Y Ciencia, 2010
* Las fotografías que se presentan son propiedad del autor y fueron tomadas durante el trabajo de... more * Las fotografías que se presentan son propiedad del autor y fueron tomadas durante el trabajo de campo.
Investigación y …, 2009
... de manifestar, de esta manera, estabilidad en el rendimiento a través del tiempo, lo cual con... more ... de manifestar, de esta manera, estabilidad en el rendimiento a través del tiempo, lo cual concuerda con lo repor-tado por Muñoz (1973) y ... para rendimiento económico y número de dientes por bulbo promedio en los clo-nes avanzados más sobresalientes de ajo Perla y testigo ...
Ecological Modelling, 2009
The greatest concentration of oak species in the world is believed to be found in Mexico. These s... more The greatest concentration of oak species in the world is believed to be found in Mexico. These species are potentially useful for reforestation because of their capacity to adapt to diverse environments. Knowledge of their geographic distribution and of species-environment relations is essential for decision-making in the management and conservation of natural resources. The objectives of this study were to develop a model of the distribution of Quercus emoryi Torr. in Mexico, using geographic information systems and data layers of climatic and other variables, and to determine the variables that significantly influence the distribution of the species. The study consisted of the following steps: (A) selection of the target species from a botanical scientific collection, (B) characterization of the collecting sites using images with values or categories of the variables, (C) model building with the overlay of images that meet the habitat conditions determined from the characterization of sites, (D) model validation with independent data in order to determine the precision of the model, (E) model calibration through adjustment of the intervals of some variables, and (F) sensitivity analysis using precision and concordance non-parametric statistics applied to pairs of images. Results show that the intervals of the variables that best describe the species' habitat are the following: altitude from 1650 to 2750 amsl, slope from 0 to 66 • ; average minimum temperature of January from −12 to −3 • C; mean temperature of June from 11 to 25 • C; mean annual precipitation from 218 to 1225 mm; soil units: lithosol, eutric cambisol, haplic phaeozem, chromic luvisol, rendzina, luvic xerosol, mollic planosol, pellic vertisol, eutric regosol; type of vegetation: oak forest, oak-pine forest, pine forest, pine-oak forest, juniperus forest, low open forest, natural grassland and chaparral. The resulting model of the geographic distribution of Quercus emoryi in Mexico had the following values for nonparametric statistics of precision and agreement: Kappa index of 0.613 and 0.788, overall accuracy of 0.806 and 0.894, sensitivity of 0.650 and 0.825, specificity of 0.963, positive predictive value of 0.945 and 0.957 and negative predictive value of 0.733 and 0.846. Results indicate that the variable average minimum temperature of January, with a maximum value of −3 • C, is an important factor in limiting the species' distribution.