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94 resultados encontrados para: AUTOR: Perales Rivera, Hugo Rafael
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1.
- Artículo con arbitraje
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Resumen en: Español | Inglés |
Resumen en español

En este estudio, se evaluó el efecto de variables (disponibilidad de alimento y cavidades, competencia, depredación y presión de cacería) sobre la abundancia y densidad poblacional de Cuniculus paca. Se determinó el uso de hábitat de esta especie en tres sitios con distinto uso de suelo (Reserva de la Biosfera Montes Azules, reservas ejidales y sitios antrópicos) en la Selva Lacandona, Chiapas, México. Desde la perspectiva de los sistemas fuente-sumidero, se propuso que C. paca utilizaría selectivamente el hábitat con mayor disponibilidad de alimento y cavidades (hábitats fuente), donde presentaría mayor densidad poblacional. Se realizaron 12 transectos en tres sitios con diferente uso de suelo, donde se estimó la disponibilidad de alimento y cavidades potenciales para C. paca. A lo largo de éstos, se colocaron 4 trampas-cámara (cada 200 m) para determinar la abundancia relativa del tepezcuintle, sus competidores potenciales y depredadores. Por medio de la identificación de individuos a través de las foto capturas, se obtuvo la densidad, misma con la que se determinó el uso de hábitat por medio de pruebas de chi-cuadrada e intervalos de Bonferroni. Se construyeron modelos lineales generalizados para analizar el efecto de diversas variables sobre la abundancia y densidad de C. paca. En temporada seca se registraron 0.05 fotografías/100 días-cámara y en la de lluvias 0.08 fotografías/100 días-cámara, además de una densidad de 54 individuos/km2 en ambas temporadas. La disponibilidad de cavidades fue la única variable que mostró efecto significativo sobre las densidades del tepezcuintle (P = 0.04 temporada seca, P = 0.006 temporada de lluvias). Las reservas ejidales en temporada seca, se utilizaron más de lo esperado con base en su disponibilidad (X2 = 28.8; P = 0.0001). En la temporada lluviosa, los tres hábitats fueron utilizados en proporción a su disponibilidad.

Los resultados sugieren que las cavidades utilizadas como refugio estarían direccionando las dinámicas poblacionales del tepezcuintle y son un recurso clave dentro de los requerimientos de hábitat de esta especie en la zona de estudio. Se propone que la Reserva Ejidal y la Reserva de la Biósfera Montes Azules podrían considerarse hábitat fuente, ya que ambos contaron con mayor disponibilidad de cavidades adecuadas para la protección de los adultos y sus crías, mayores densidades, además de la presencia de crías tomada como indicador del éxito reproductivo. Por su parte, el hábitat antrópico sería sumidero, por tener menor disponibilidad de cavidades adecuadas, menor densidad poblacional y ausencia de crías. La conservación a largo plazo y manejo de hábitat del tepezcuintle en paisajes transformados, dependerán en gran parte de la distribución y conectividad entre y dentro de los diferentes tipos de hábitats.

Resumen en inglés

In this study, the effect of relevant variables (availability of food and cavities, competition, predation, and hunting pressure) on the relative abundance and population density of the spotted lowland paca (Cuniculus paca) was assessed. In addition, habitat use of this species at three sites with different land use regime (Montes Azules Biosphere Reserve, community reserves, and anthropic sites) in the Lacandon Rainforest, Chiapas, Mexico was analysed. From the perspective of the source-sink systems, it was predicted that pacas selectively would use the habitat with higher food and cavity availability (source habitats), where higher densities were expected. Twelve transects were located in three sites with different land use regimes, where food availability and potential cavities used by pacas were assessed. Along these transects, 4 camera-traps were deployed every 200 meters to estimate the relative abundance of pacas and their potential competitors and predators. Photo-captured individuals were identified to estimate population density and seasonal variation in habitat use. Generalized linear models (GLM) were constructed to analyse the effects of several variables on paca abundance and density. A relative abundance of 0.05 and 0.08 paca photographs/100 camera-days were recorded in the dry and the rainy season, respectively. A density of 54 pacas/km2 was estimated in both seasons. The availability of cavities was the only variable that showed a significant effect on paca density (P = 0.04 for the dry season, and P = 0.006 for the rainy season). Community reserves were used in the dry season more than expected from their availability in the study area (x2 = 28.8; P = 0.0001). In the rainy season, all three sites were used by paca in proportion to their availability.

Our results suggest that the cavities used as refuges by pacas drive their population dynamics, and constitute a key habitat resource for them in the study area. We propose that the Ejidal Reserve and Montes Azules Biosphere Reserve may be source habitats supporting higher paca densities and greater availability of adequate cavities to protect adults and their offspring. On the other hand, areas transformed into croplands and grasslands for livestock production would represent sink habitats with lower paca densities, less availability of adequate cavities, and absence of offspring. The long-term conservation and habitat management of pacas in transformed landscapes will probably rely on the distribution and connectivity between and within the different habitat types available in the study area.


2.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
Agricultural change and resilience: agricultural policy, climate trends and market integration in the Mexican maize system
Eakin, Hallie ; Sweeney, Stuart (coaut.) ; Lerner, Amy M. (coaut.) ; Appendini, Kirsten Albrechtsen de (coaut.) ; Perales Rivera, Hugo Rafael (coaut.) ; Steigerwald, Douglas G. (coaut.) ; Dewes, Candida F. (coaut.) ; Davenport, Frank (coaut.) ; Bausch, Julia C. (coaut.) ;
Contenido en: Anthropocene Vol. 23 (September 2018), p. 43-52 ISSN: 2213-3054
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

Ensuring that national food systems have capacity to withstand volatility and shocks is a growing concern. Given the complex processes involved, multi-scalar, multi-stressor analyses of critical food systems are needed. This paper presents a multi-scalar analysis of the Mexican maize system to provide insight into the sector’s evolution. The literature suggests that, over the last 30 years, climate trends, domestic and international market dynamics, and domestic policy changes have affected Mexico’s maize sector. In contrast, this study finds no conclusive evidence of wide-spread abandonment of maize. In addition, while economic globalization and climatic changes are often presented as the primary drivers of change in Mexico’s maize sector, results of this study show that domestic policy has been equally, if not more, influential in the sector’s evolution. More than international market integration, the relatively recent geographic concentration of commercial supplies within Mexico has increased national sensitivity to idiosyncratic shocks affecting the dominant supply region. In this light, smallholder persistence across Mexico may represent an underutilized strategic asset in policy efforts to enhance both domestic food security and national-level resilience. The Mexican case illustrates the potential role for proactive domestic policy in shaping sensitivities in the national food system to both internal and exogenous shocks.


3.
- Capítulo de libro con arbitraje
Agronomic and economic competitiveness of maize landraces and in situ conservation in Mexico
Perales Rivera, Hugo Rafael ; Brush, Stephen B. (coaut.) ; Qualset, Calvin O. (coaut.) ;
Contenido en: Farmers gene banks and crop breeding: economic analyses of diversity in wheat maize and rice Norwell, Massachusetts : Kluwer Academic Publishers, 1998 p. 109-125 ISBN:978-0-7923-8370-3
Resumen en: Inglés |
Resumen en inglés

When public attention initially focused on the conservation of crop genetic resources in the late 1960s, scientists advocated ex situ conservation because of their belief that modern varieties would inevitably replace traditional varieties (Frankel, 1970a, 1970b). This belief was based on two key assumptions. The first, explicit assumption is that modern varieties are always superior to traditional varieties in yield and economic profitability. A second, implicit assumption is that all farmers share the objective of maximizing expected profits. Since superior modern varieties would sooner or later replace landraces, in situ conservation of crops was dismissed a priori as non-viable. Interventions such as subsidies would be required to maintain cultivation of traditional varieties in the face of the high opportunity costs of growing them (Ford-Lloyd and Jackson, 1986), especially as greater food production was needed to feed the ever- increasing world population.


4.
Artículo
*En hemeroteca, SIBE-Tapachula
Alternativas de control de Leptophobia aripa en el cultivo de repollo en Los Altos de Chiapas, México
Santiago Lastra, José Antonio (autor) ; García Barrios, Luis Enrique (autor) ; Perales Rivera, Hugo Rafael (autor) ; Rojas, Julio C. (autor) ;
Clasificación: AR/635.34996 / A4
Contenido en: Manejo Integrado de Plagas y Agroecología No. 79-80 (2008), p. 49-58 ISSN: 1659-0082
Bibliotecas: San Cristóbal , Tapachula
Cerrar
SIBE San Cristóbal
ECO010002293 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
28627-40 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Tapachula
Resumen en español

Los campesinos asperjan en forma intensa e inadecuada metamidofós en el cultivo de repollo (Brassica oleracea L. var. capitata D. C.) para controlar el gusano rayado (Leptophobia aripa Boisd.) y otras plagas en la región de Los Altos de Chiapas, México. Resulta conveniente comparar este método convencional de control con insecticidas organosintéticos con formas alternativas de control, para reducir o eliminar los efectos negativos del combate convencional sobre el ambiente y la salud. Se evaluaron cuatro estrategias en forma experimental: (i) aspersión de un piretroide comercial (Ambush 50); (ii) control biológico mediante Bacillus thuringiensis Berliner var. kurstaki; (iii) aspersión del extracto acuoso de cempoalxóchitl (Tagetes erecta L.); y (iv) dos tipos de asociaciones aditivas: repollo asociado con cuatro diferentes densidades de T. erecta, con la finalidad de crear una barrera física o química, y repollo asociado a nabito (Brassica campestris L.), que es una hospedera alternativa. La oviposición de L. aripa no fue menor por la asociación del repollo con T. erecta. Las asociaciones con altas densidades de T. erecta tuvieron un efecto fuerte de supresión por competencia sobre el repollo. L. aripa mostró preferencia por ovipositar en B. campestris, pero la reducción de larvas en los repollos asociados fue insignificante. El insecticida piretroide (Ambush 50) y B. thuringiensis tuvieron un control efectivo sobre L. aripa. Es factible promover su uso en la región mediante estrategias de manejo para evitar el desarrollo de resistencia de los organismos plaga a estos insecticidas.

Resumen en inglés

Control alternatives for Leptophobia aripa in cabbage in the highlands of Chiapas, Mexico. Producers spray cabbage (Brassica oleracea L. var. capitata D. C.) fields frequently and inadequately with methamidophos to control the mountain white butterfly (Leptophobia aripa Boisd.) and other pests in the highlands of Chiapas State, Mexico. The objective of the present study was to compare this conventional method (chemical) with some potentially effective and less contaminant methods that could reduce or eliminate environmental and health side effects. We evauated four strategies: (i) a commercial pyrethroid (Ambush 50); (ii) biological control with Bacillus thuringiensis Berliner var. kurstaki; (iii) a water-based marigold extract (Tagetes erecta L.); and (iv) two types of associated crops: cabbage associated to marigold sown at four different densities to create physical-chemical barriers, and cabbage associated to another brassica plant (Brassica campestris L.) to lure L. aripa towards B. campestris. Oviposition on cabbages was not significantly reduced by intercropping with marigold when compared to untreated plots used as controls. Confusing effects occurred, as cabbage size and yield were reduced at high marigold densities. B. campestris attracted significantly more ovipositing females and hosted more late larvae instars than cabbage, but the consequent reduction in cabbage infestation was statistically marginal. Applications of the pyrethroid and B. thuringiensis effectively controlled L. aripa larvae. These two alternatives could be readily used in the region, alongside strategies to avoid rapid development of resistance to them by L. aripa.


5.
Artículo
Assessing maize genetic erosion
Brush, Stephen B. ; Bellon Corrales, Mauricio Rafael (coaut.) ; Hijmans, Robert J. (coaut.) ; Orozco Ramírez, Quetzalcóatl (coaut.) ; Perales Rivera, Hugo Rafael (coaut.) ; Van Etten, Jacob (coaut.) ;
Contenido en: PNAS. Proceedings of the National Academy of Sciences of the United States of America Vol. 112, no. 1, E1 (January 2015), p. E1-E1 ISBN:1091-6490
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6.
- Artículo con arbitraje
Asymmetrical local adaptation of maize landraces along an altitudinal gradient
Mercer, Kristin L. ; Martínez Vázquez, Ángel (coaut.) ; Perales Rivera, Hugo Rafael (coaut.) ;
Contenido en: Evolutionary Applications Vol. 1, no. 3 (August 2008), p. 489-500 ISSN: 1752-4571
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Resumen en: Inglés |
Resumen en inglés

Crop landraces are managed populations that evolve in response to gene flow and selection. Cross-pollination among fields, seed sharing by farmers, and selection by management and environmental conditions play roles in shaping crop characteristics. We used common gardens to explore the local adaptation of maize (Zea mays ssp. mays) landrace populations from Chiapas, Mexico to altitude. We sowed seeds of 21 populations from three altitudinal ranges in two common gardens and measured two characteristics that estimate fitness: likelihood of producing good quality seed and the total mass of good quality seed per plant. The probability of lowland plants producing good quality seed was invariably high regardless of garden, while highland landraces were especially sensitive to altitude. Their likelihood of producing good seed quadrupled in the highland site. The mass of good quality seed showed a different pattern, with lowland landraces producing 25% less seed mass than the other types at high elevations. Combining these two measures of fitness revealed that the highland landraces were clearly adapted to highland sites, while lowland and midland landraces appear more adapted to the midland site. We discuss this asymmetry in local adaptation in light of climate change and in situ conservation of crop genetic resources.


7.
Tesis
El autoconsumo en el agricultura de los popolucas de Soteapán, Veracruz / Hugo Rafael Perales Rivera
Perales Rivera, Hugo Rafael ;
Texcoco, Estado de México, México : Colegio de Postgraduados. Instituto de Enseñanza e Investigación en Ciencias Agrícolas , 1992
Clasificación: T/338.17262 / P4
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
SAT000092 (Disponible)
Disponibles para prestamo: 1

8.
Artículo
Availability and characterization of cavities used by pacas (Cuniculus paca) in the Lacandon Rainforest, Chiapas, Mexico
Figueroa de León, Avril ; Naranjo Piñera, Eduardo Jorge (coaut.) (1963-) ; Perales Rivera, Hugo Rafael (coaut.) ; Santos Moreno, Antonio (coaut.) ; Lorenzo Monterrubio, Consuelo (coaut.) ;
Contenido en: Revista Mexicana de Biodiversidad Vol. 87, no. 3 (September 2016), p. 1062–1068 ISSN: 1870-3453
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Resumen en: Español | Inglés |
Resumen en español

Los estudios sobre cavidades utilizadas como refugio son necesarios para desarrollar planes efectivos de manejo y conservación de las especies silvestres y sus hábitats. Las variables que influyen en el uso de las cavidades por parte del tepezcuintle (Cuniculus paca) en la Selva Lacandona, Chiapas, México, aún no han sido estudiadas. El objetivo de este trabajo fue identificar las características distintivas de las cavidades que son utilizadas por el tepezcuintle y verificar si las utiliza en proporción a su disponibilidad en 3 sitios con diferente uso de suelo. Se detectaron y caracterizaron 42 cavidades que potencialmente fueron utilizadas por esta especie. Con ayuda de cámaras trampa, la presencia de C. paca fue verificada en 24 cavidades. Se analizaron las diferencias entre las cavidades con presencia y ausencia de tepezcuintle. En el área de estudio, esta especie utiliza cavidades bajo raíces de árboles en pie y dentro de troncos tirados que se encuentran a menos de 100 m de distancia de cuerpos y corrientes de agua, en vegetación secundaria y ribereña. El tepezcuintle es considerablemente tolerante a alteraciones antrópicas y a los cambios de uso de suelo, adaptándose fácilmente a la fragmentación del paisaje.

Resumen en inglés

The studies of cavities used as refuges are necessary to develop effective management and conservation plans for native wildlife species and their habitats. There are no previous studies about the variables that influence the use of cavities by pacas (Cuniculus paca) in the Lacandon Rainforest of Chiapas, Mexico. The aims of this study were to identify distinctive characteristics of cavities used by pacas and to verify if these rodents used the cavities in proportion to their availability. We studied 3 sites with different land use where 42 cavities potentially used by pacas were detected and characterized, the presence of pacas was confirmed in 24 cavities using camera traps. The differences between cavities with and without paca presence were analyzed. In the study area, pacas used cavities underneath roots and inside fallen logs in secondary and riparian vegetation that were within 100 m from water bodies. Pacas are considerably tolerant to anthropogenic disturbances such as land use change, thereby easily adapting to fragmented landscapes.


9.
Capítulo de libro
*Solicítelo con su bibliotecario/a
Biotecnología y agroecología: ciencia, técnica y conflictos de interés
Perales Rivera, Hugo Rafael ;
Contenido en: Ciencia y humanismo 2012: memorias México, D. F. : Academia Mexicana de Ciencias, 2012 p. 505
Nota: Solicítelo con su bibliotecario/a

10.
Artículo
Cavity occupancy by lowland paca (Cuniculus paca) in the Lacandon Rainforest, Chiapas, Mexico
Figueroa de León, Avril ; Naranjo Piñera, Eduardo Jorge (coaut.) (1963-) ; Perales Rivera, Hugo Rafael (coaut.) ; Santos Moreno, Antonio (coaut.) ; Lorenzo Monterrubio, Consuelo (coaut.) ;
Contenido en: Tropical Conservation Science Vol. 9, no. 1 (March 2016), p. 246-263 ISSN: 1940-0829
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Resumen en: Inglés |
Resumen en inglés

Habitat occupancy is a good indicator of wildlife behavior and interactions with their environment. We used camera traps to study the use of cavities by lowland paca (Cuniculus paca) in three sites in the Lacandon Rainforest of Chiapas, Mexico. To understand the biotic, environmental, physical, anthropic, and behavioral elements that affect spotted lowland paca, the cameras recorded lowland paca activity in front of 29 cavities. Monitoring occurred continuously in cavities near permanent natural water bodies, underneath roots of trees, or inside hollow logs. These cavities were more frequently found in Montes Azules Biosphere Reserve (MABR), where hunting pressure was low. The daily occupancy and permanence of lowland paca in these cavities were associated with the presence of its offspring. There were no offspring recorded in cavities alongside rivers within grazing areas. This suggests the potential existence of a sink-source type of metapopulation, where community reserves and MABR would serve as source habitat, while riparian corridors would be sink habitat for this species. Lowland pacas used these locations, which were scattered through the study area, so long as hunting was moderate and riparian corridors with safe cavities in large trees were well preserved.