Edmundo García-Moya | Colegio de Postgraduados (original) (raw)
Papers by Edmundo García-Moya
Invasive Plant Science and Management, 2014
Resumen El venado de Coues (Odocoileus virginianus couesi) es una de las 14 subespecies de venado... more Resumen El venado de Coues (Odocoileus virginianus couesi) es una de las 14 subespecies de venado cola blanca en México, se distribuye sobre 30.4 % de la república mexicana y es de alto valor cinegético. Se realizó una investigación en la Sierra del Laurel, municipio Calvillo, Aguascalientes, México, de la densidad del venado cola blanca en respuesta a los atributos del hábitat, estimada mediante el recuento de grupos fecales. El hábitat se describió por sus características topográficas, florístico-estructurales y agua disponible. Se determinó que la densidad fue mayor en el matorral subtropical, seguida de la presente en el bosque de Quercus y del pastizal inducido. Las variables que contribuyeron a explicar la abundancia fueron el tipo de vegetación, el índice de equidad de Pielou, el índice de predominio de Simpson, la densidad de Ipomoea murucoides, la riqueza florística y la altura media de las arbustivas, así como el porcentaje de suelo desnudo. No obstante, la existencia de otros factores demográficos del venado, como la relación de sexos, y de tipo antrópico como la fragmentación del hábitat, el sobrepastoreo, la caza furtiva, la presencia de paseantes y la proliferación de obras para ecoturismo no pueden descartarse como posibles causas de una mayor abundancia de este cérvido en el matorral subtropical, por lo que se requiere de la realización de más estudios sobre el particular. Abstract The Coues deer (Odocoileus virginianus couesi) is one of the 14 subspecies of white-tailed deer in Mexico and its distribution area encompasses 30.4 % of the Mexican Republic and it has a high cinegetic value. A research was carried out in Sierra del Laurel, in the municipality of Calvillo, Aguascalientes, Mexico, on the density of the white-tailed deer in response to the characteristics of the habitat, estimated by means of the count of fecal pellet groups. The habitat was characterized by its topographic and floral-structural traits and by availability of water. The density was determined to be higher in the subtropical shrubland, followed by that of the Quercus forest and of the induced grassland. The variables which accounted for the abundance of this deer species were vegetation type, Pielou's equity index, Simpson's predominance index, the density of Ipomoea murucoides, the floral wealth and the mean height of the shrubs, and the percentage of naked soil. However, the existence of other demographic factors of the dear, such as the sex ratios, as well as anthropic factors including the fragmentation of the habitat, overgrazing, furtive hunting, the presence of hikers and the proliferation of constructions for ecotourism cannot be discarded as possible causes of a larger abundance of this cervid in the subtropical shrubland; therefore, further studies on this topic are required.
Botanical Science, Feb 2015
Hintonia latiflora (Sessé & Moc. ex DC.) Bullock, the “quina amarilla”, is an American tree of th... more Hintonia latiflora (Sessé & Moc. ex DC.) Bullock, the “quina amarilla”, is an American tree of the tropical deciduous forest which is valuable because its bark has medicinal properties. The main area supplying the commercial quina amarilla is the northern of Guerrero state, Mexico. This contribution reports bibliographic information pertaining to the natural history and har- vesting in its whole distribution area. Also, it includes field data on the habitat, density, phenology, dispersal, architecture, harvest intensity, and commercialization in some populations from the upper Rio Balsas Basin. The results shows biophysical factors that are important for growth, establishment, and survival of the species. Phenology consists of flowering in spring-summer, foliation in summer, fruiting in late summer, and dispersal in winter. The dispersal is anemocorous and barocorous. Tree architecture is related to environmental factors and to bark harvesting. Density and availability of the species changes with site characteristics and the intensity of the harvesting. The commercialization involves three actors: gatherers, local middlemen, and regional traders. The historical prices of the bark to the consumers have increased, but considering inflation, really have decreased. The major threat to the populations of H. latiflora is harvesting intensity and careless practice of harvesting.
Hintonia latiflora (Sessé & Moc. ex DC.) Bullock, la “quina amarilla”, es un árbol americano propio del bosque tropical caducifolio, valioso, debido a que la corteza tiene propiedades medicinales. La principal zona de abasto comercial de quina amarilla está al norte del estado de Guerrero, México. Esta contribución aporta información bibliográfica en torno a la historia natural y del aprovechamiento de H. latiflora en toda su área de distribución. Además, incorpora datos de campo originales acerca del hábitat, densidad, fenología, dispersión, arquitectura, comercialización e intensidad en el aprovechamiento de algunas pobla- ciones de quina amarilla de la cuenca alta del Río Balsas. Se encontraron factores biofísicos importantes para el establecimiento, crecimiento y supervivencia de la especie. La fenología consiste en la floración en la primavera-verano, foliación en el verano, fructificación a finales del verano y dispersión durante el invierno. La dispersión es anemócora y barócora. La arquitectura arbórea se relaciona con factores ambientales y la cosecha de corteza. Se observó que la densidad y disponibilidad de la especie cambian con las características de los sitios y con la intensidad de recolección. La comercialización de la quina implica a tres actores: los recolectores, los acopiadores locales y los compradores regionales. Los precios históricos de la corteza al consumidor han aumentado pero al considerar los precios sin inflación, realmente han bajado. Se destaca que la mayor amenaza para las poblaciones es la intensidad de aprovechamiento y la práctica descuidada de la cosecha.
Revista de Biología Tropical, 2006
Wild turkey (Meleagris gallopavo L.) was extirpated from "Sierra Fria", Aguascalientes,... more Wild turkey (Meleagris gallopavo L.) was extirpated from "Sierra Fria", Aguascalientes, Mexico, around the 50´s, but was reestablished in the area between 1992 and 1994. At present, the species is abundant in "Sierra Fria"; however, little is known about its food habits, reason which motivated the present study. The objective of this study was to document the diet composition of
Acta Botánica …, 1996
Acta Botánica Mexicana Instituto de Ecología AC murillom@ecologia.edu.mx ISSN (Versión impresa): ... more Acta Botánica Mexicana Instituto de Ecología AC murillom@ecologia.edu.mx ISSN (Versión impresa): 0187-7151 MÉXICO ... 1996 Gerardo Armando Aguado Santacruz / Edmundo García Moya / Cruz Velasco González / José Luis Flores Flores IMPORTANCIA DE LOS ...
Técnica Pecuaria en …
Los mecanismos de adaptación de las plantas a los factores ambientales se manifiestan en sus rasg... more Los mecanismos de adaptación de las plantas a los factores ambientales se manifiestan en sus rasgos morfológicos, fisiológicos y de crecimiento. La identificación de estos rasgos en especies de gramíneas nativas permite identificar germoplasma con características particulares de ...
Plant Ecology, 2004
Cover data for 93 perennial plant species from fifty 1 ha sites, were used to ordinate desert veg... more Cover data for 93 perennial plant species from fifty 1 ha sites, were used to ordinate desert vegetation in relation to 50 environmental variables at El Huizache Corridor. Cumulative variance recovered in the Bray and Curtis variance-regression ordination was substantial (80%). Community structure of desert plant communities at El Huizache Corridor may be influenced primarily by a combination of landscape and edaphic variables, which in turn may determine the distribution and abundance of moisture and nutrients, and perhaps promote habitat specialization and or competitive exclusion. Secondly, to a lesser extent, climate variables could be influencing community organization at small scale gradients, the longer the gradient the more relevant climatic factors become. First axis represented a landscape gradient; it was positively correlated to exposure, geology, slope angle, rocks, stoniness, iron, January mean temperature, and organic matter content; it was negatively correlated with latitude, longitude, soil depth, and potassium content. The second axis represented mainly a climatic gradient; it was positively correlated with mean precipitation of January, February, July, August, September, November, December, annual mean precipitation, Lang's Index, organic matter content, and stoniness. The third axis represented an edaphic gradient; it was positively correlated with electrical conductivity, Mn, Zn and elevation, and negatively correlated with pH, nitrates, Ca, and disturbance. These findings should guide conservation efforts to maintain species diversity and endemism at this area.
Rangeland Ecology & Management, 2007
Acta Zoologica Mexicana (n.s.), Sep 1, 2008
Habitat use by the Coues white tailed deer (Odocoileus virginianus couesi) was documented during ... more Habitat use by the Coues white tailed deer (Odocoileus virginianus couesi) was documented during the dry season of 2006, in the Sierra del Laurel, Aguascalientes, Mexico. Based on logistic regression analyses, the objective of this study was to determine which floristic-structural and topographical features influence the probability of habitat use by the Coues deer. Vegetation, slope, altitude and distance to water were significant (p < 0.01) in the probability of habitat use. The thresholds for slope, altitude and distance were estimated for a high probability of use p (y≥0.5) and varied due to vegetation type. Sites on subtropical vegetation with 50 trees of Ipomoea murucoides Roem. & Schult by hectare and 350 shrubs of Eysenhardtia polystachya Ortega Sarg., and mean height of the shrub layer over the 2.0 meters, had a probability of use greater than 50 percent. However this vegetation type is scarce and threatened by agricultural development in the Sierra del Laurel. The results of this research clearly point out the need to promote management and conservation strategies of this type of vegetation since it is the preferred habitat of the Coues deer, which in turn should be considered as an asset by the state holders and an option to derive additional income from hunting fees and other economic activities pertaining to a multiple use of the land.
Acta Zoológica Mexicana (n.s.), May 1, 2007
The use of dams by the Mexican duck (Anas diazi Ridway, 1886) was documented between September 19... more The use of dams by the Mexican duck (Anas diazi Ridway, 1886) was documented between September 1994 and March 1995, in the region of El Llano, located in Mexico between Aguascalientes and Jalisco. The objective of this study was to determine which type of dam is more frequently used by this species, based on a use-availability water analyses. The results point out a superior use than expected of the reservoirs used as water storage which are pumped for irrigation, throughout fall and part of winter. These dams can be vital for the breeding of ducklings in Mexico. The identification and evaluation of the dams which are more frequently used by the Mexican duck will allow developing strategies for their conservation and sustainable use.
Prosopis laevigata and Mimosa biuncifera are frequently found in arid and semiarid shrublands, bu... more Prosopis laevigata and Mimosa biuncifera are frequently found in arid and semiarid shrublands, but scarce information is available about their influence on plant community structure and soil fertility. We compared plant community structure, diversity and soil nutrients of three semiarid shrubland sites located in Mezquital Valley, Mexico. These sites differ in their dominant species: Site 1 (Bingu) P. laevigata, Site 2 (González) M. biuncifera, and Site 3 (Rincón) with the presence of both legumes. The results showed that the plant community with P. laevigata and M. biuncifera (Site 3) had more cover, taller plants and higher plant diversity than sites with only one legume (Site 1 and Site 2). Soil organic matter (SOM), soil organic carbon (SOC), total nitrogen (TN), phosphorus-Olsen (P) and C mineralization were higher in the soil under the canopy of both legumes than in bare soil. In contrast, soil cation concentrations were lower under the canopy of P. laevigata, but not for M. biuncifera. In addition, the density of arbuscular mycorrhizal fungi spores was higher within the soil under the canopy of M. biuncifera than in the soil under the canopy of P. laevigata. Thus, resource islands (RI) created by P. laevigata increased the amounts of SOC, TN and P when compared with the RI of M. biuncifera. This study provided evidences about the importance of species identity in order to expand the niche availability for the establishment of other plants, and highlights that P. laevigata and M. biuncifera jointly influencing plant colonization within semiarid ecosystems
Se estudió el proceso germinativo de tres especies de Cephalocereus (C. apicicephalium, C. nizand... more Se estudió el proceso germinativo de tres especies de Cephalocereus (C. apicicephalium, C. nizandensis, C. totolapensis) endémicas del Itsmo de Tehuantepec, Oaxaca, México, bajo las hipótesis de que las semillas perderán la capacidad germinativa a medida que pasen los días después de la recolección y que la germinación es diferente entre especies, pero no entre poblaciones de la misma especie. Para cada una de las especies estudiadas, se recolectaron semillas de poblaciones diferentes y se sembraron en cuatro fechas distintas, colocando 30 semillas en dos o tres cajas de Petri. Las cajas se colocaron en una cámara de ambiente controlado y la germinación se registró diariamente durante 30 días, considerando una semilla germinada cuando emergía la radícula. Los porcentajes de germinación (38.8% en C. totolapensis, 55.1% en C. apicicephalium) y la velocidad de germinación (1.6 en C. apicicephalium, Guiengola-2 a 24 en C. apicicephalium, Guiengola-1 y C. nizandensis, La Mata) fueron sig...
Fagus grandifolia subsp. mexicana is a species restricted to small populations under high anthrop... more Fagus grandifolia subsp. mexicana is a species restricted to small populations under high anthropogenic pressure. With the aim to attain information to propose conservation strategies of this species, the seed rain and demography of current-year seedlings were analyzed at La Mojonera, Hidalgo, Mexico. A 4 800 m 2 plot divided into 10 X 10 m quadrants was established. The seed
Canada, the United States and Mexico all have a Ion history of rangeland monitoring. However none... more Canada, the United States and Mexico all have a Ion history of rangeland monitoring. However none have developed a nationwi ? e database or even a standardized set of protocols. The lack of standardization, inadequately developed relationships between management objectives and monitoring protocols, and an emphasis on data collection rather than analysis and interpretation have limited the value of past
Natural regeneration of eight species of trees in three different types of gaps caused by selecti... more Natural regeneration of eight species of trees in three different types of gaps caused by selective logging of mahogany in a rainforest of Quintana Roo, Mexico, was studied. Point centered quarter method was applied randomly in each of the 10 replications per site. Height and density of the seedling
Invasive Plant Science and Management, 2014
Resumen El venado de Coues (Odocoileus virginianus couesi) es una de las 14 subespecies de venado... more Resumen El venado de Coues (Odocoileus virginianus couesi) es una de las 14 subespecies de venado cola blanca en México, se distribuye sobre 30.4 % de la república mexicana y es de alto valor cinegético. Se realizó una investigación en la Sierra del Laurel, municipio Calvillo, Aguascalientes, México, de la densidad del venado cola blanca en respuesta a los atributos del hábitat, estimada mediante el recuento de grupos fecales. El hábitat se describió por sus características topográficas, florístico-estructurales y agua disponible. Se determinó que la densidad fue mayor en el matorral subtropical, seguida de la presente en el bosque de Quercus y del pastizal inducido. Las variables que contribuyeron a explicar la abundancia fueron el tipo de vegetación, el índice de equidad de Pielou, el índice de predominio de Simpson, la densidad de Ipomoea murucoides, la riqueza florística y la altura media de las arbustivas, así como el porcentaje de suelo desnudo. No obstante, la existencia de otros factores demográficos del venado, como la relación de sexos, y de tipo antrópico como la fragmentación del hábitat, el sobrepastoreo, la caza furtiva, la presencia de paseantes y la proliferación de obras para ecoturismo no pueden descartarse como posibles causas de una mayor abundancia de este cérvido en el matorral subtropical, por lo que se requiere de la realización de más estudios sobre el particular. Abstract The Coues deer (Odocoileus virginianus couesi) is one of the 14 subspecies of white-tailed deer in Mexico and its distribution area encompasses 30.4 % of the Mexican Republic and it has a high cinegetic value. A research was carried out in Sierra del Laurel, in the municipality of Calvillo, Aguascalientes, Mexico, on the density of the white-tailed deer in response to the characteristics of the habitat, estimated by means of the count of fecal pellet groups. The habitat was characterized by its topographic and floral-structural traits and by availability of water. The density was determined to be higher in the subtropical shrubland, followed by that of the Quercus forest and of the induced grassland. The variables which accounted for the abundance of this deer species were vegetation type, Pielou's equity index, Simpson's predominance index, the density of Ipomoea murucoides, the floral wealth and the mean height of the shrubs, and the percentage of naked soil. However, the existence of other demographic factors of the dear, such as the sex ratios, as well as anthropic factors including the fragmentation of the habitat, overgrazing, furtive hunting, the presence of hikers and the proliferation of constructions for ecotourism cannot be discarded as possible causes of a larger abundance of this cervid in the subtropical shrubland; therefore, further studies on this topic are required.
Botanical Science, Feb 2015
Hintonia latiflora (Sessé & Moc. ex DC.) Bullock, the “quina amarilla”, is an American tree of th... more Hintonia latiflora (Sessé & Moc. ex DC.) Bullock, the “quina amarilla”, is an American tree of the tropical deciduous forest which is valuable because its bark has medicinal properties. The main area supplying the commercial quina amarilla is the northern of Guerrero state, Mexico. This contribution reports bibliographic information pertaining to the natural history and har- vesting in its whole distribution area. Also, it includes field data on the habitat, density, phenology, dispersal, architecture, harvest intensity, and commercialization in some populations from the upper Rio Balsas Basin. The results shows biophysical factors that are important for growth, establishment, and survival of the species. Phenology consists of flowering in spring-summer, foliation in summer, fruiting in late summer, and dispersal in winter. The dispersal is anemocorous and barocorous. Tree architecture is related to environmental factors and to bark harvesting. Density and availability of the species changes with site characteristics and the intensity of the harvesting. The commercialization involves three actors: gatherers, local middlemen, and regional traders. The historical prices of the bark to the consumers have increased, but considering inflation, really have decreased. The major threat to the populations of H. latiflora is harvesting intensity and careless practice of harvesting.
Hintonia latiflora (Sessé & Moc. ex DC.) Bullock, la “quina amarilla”, es un árbol americano propio del bosque tropical caducifolio, valioso, debido a que la corteza tiene propiedades medicinales. La principal zona de abasto comercial de quina amarilla está al norte del estado de Guerrero, México. Esta contribución aporta información bibliográfica en torno a la historia natural y del aprovechamiento de H. latiflora en toda su área de distribución. Además, incorpora datos de campo originales acerca del hábitat, densidad, fenología, dispersión, arquitectura, comercialización e intensidad en el aprovechamiento de algunas pobla- ciones de quina amarilla de la cuenca alta del Río Balsas. Se encontraron factores biofísicos importantes para el establecimiento, crecimiento y supervivencia de la especie. La fenología consiste en la floración en la primavera-verano, foliación en el verano, fructificación a finales del verano y dispersión durante el invierno. La dispersión es anemócora y barócora. La arquitectura arbórea se relaciona con factores ambientales y la cosecha de corteza. Se observó que la densidad y disponibilidad de la especie cambian con las características de los sitios y con la intensidad de recolección. La comercialización de la quina implica a tres actores: los recolectores, los acopiadores locales y los compradores regionales. Los precios históricos de la corteza al consumidor han aumentado pero al considerar los precios sin inflación, realmente han bajado. Se destaca que la mayor amenaza para las poblaciones es la intensidad de aprovechamiento y la práctica descuidada de la cosecha.
Revista de Biología Tropical, 2006
Wild turkey (Meleagris gallopavo L.) was extirpated from "Sierra Fria", Aguascalientes,... more Wild turkey (Meleagris gallopavo L.) was extirpated from "Sierra Fria", Aguascalientes, Mexico, around the 50´s, but was reestablished in the area between 1992 and 1994. At present, the species is abundant in "Sierra Fria"; however, little is known about its food habits, reason which motivated the present study. The objective of this study was to document the diet composition of
Acta Botánica …, 1996
Acta Botánica Mexicana Instituto de Ecología AC murillom@ecologia.edu.mx ISSN (Versión impresa): ... more Acta Botánica Mexicana Instituto de Ecología AC murillom@ecologia.edu.mx ISSN (Versión impresa): 0187-7151 MÉXICO ... 1996 Gerardo Armando Aguado Santacruz / Edmundo García Moya / Cruz Velasco González / José Luis Flores Flores IMPORTANCIA DE LOS ...
Técnica Pecuaria en …
Los mecanismos de adaptación de las plantas a los factores ambientales se manifiestan en sus rasg... more Los mecanismos de adaptación de las plantas a los factores ambientales se manifiestan en sus rasgos morfológicos, fisiológicos y de crecimiento. La identificación de estos rasgos en especies de gramíneas nativas permite identificar germoplasma con características particulares de ...
Plant Ecology, 2004
Cover data for 93 perennial plant species from fifty 1 ha sites, were used to ordinate desert veg... more Cover data for 93 perennial plant species from fifty 1 ha sites, were used to ordinate desert vegetation in relation to 50 environmental variables at El Huizache Corridor. Cumulative variance recovered in the Bray and Curtis variance-regression ordination was substantial (80%). Community structure of desert plant communities at El Huizache Corridor may be influenced primarily by a combination of landscape and edaphic variables, which in turn may determine the distribution and abundance of moisture and nutrients, and perhaps promote habitat specialization and or competitive exclusion. Secondly, to a lesser extent, climate variables could be influencing community organization at small scale gradients, the longer the gradient the more relevant climatic factors become. First axis represented a landscape gradient; it was positively correlated to exposure, geology, slope angle, rocks, stoniness, iron, January mean temperature, and organic matter content; it was negatively correlated with latitude, longitude, soil depth, and potassium content. The second axis represented mainly a climatic gradient; it was positively correlated with mean precipitation of January, February, July, August, September, November, December, annual mean precipitation, Lang's Index, organic matter content, and stoniness. The third axis represented an edaphic gradient; it was positively correlated with electrical conductivity, Mn, Zn and elevation, and negatively correlated with pH, nitrates, Ca, and disturbance. These findings should guide conservation efforts to maintain species diversity and endemism at this area.
Rangeland Ecology & Management, 2007
Acta Zoologica Mexicana (n.s.), Sep 1, 2008
Habitat use by the Coues white tailed deer (Odocoileus virginianus couesi) was documented during ... more Habitat use by the Coues white tailed deer (Odocoileus virginianus couesi) was documented during the dry season of 2006, in the Sierra del Laurel, Aguascalientes, Mexico. Based on logistic regression analyses, the objective of this study was to determine which floristic-structural and topographical features influence the probability of habitat use by the Coues deer. Vegetation, slope, altitude and distance to water were significant (p < 0.01) in the probability of habitat use. The thresholds for slope, altitude and distance were estimated for a high probability of use p (y≥0.5) and varied due to vegetation type. Sites on subtropical vegetation with 50 trees of Ipomoea murucoides Roem. & Schult by hectare and 350 shrubs of Eysenhardtia polystachya Ortega Sarg., and mean height of the shrub layer over the 2.0 meters, had a probability of use greater than 50 percent. However this vegetation type is scarce and threatened by agricultural development in the Sierra del Laurel. The results of this research clearly point out the need to promote management and conservation strategies of this type of vegetation since it is the preferred habitat of the Coues deer, which in turn should be considered as an asset by the state holders and an option to derive additional income from hunting fees and other economic activities pertaining to a multiple use of the land.
Acta Zoológica Mexicana (n.s.), May 1, 2007
The use of dams by the Mexican duck (Anas diazi Ridway, 1886) was documented between September 19... more The use of dams by the Mexican duck (Anas diazi Ridway, 1886) was documented between September 1994 and March 1995, in the region of El Llano, located in Mexico between Aguascalientes and Jalisco. The objective of this study was to determine which type of dam is more frequently used by this species, based on a use-availability water analyses. The results point out a superior use than expected of the reservoirs used as water storage which are pumped for irrigation, throughout fall and part of winter. These dams can be vital for the breeding of ducklings in Mexico. The identification and evaluation of the dams which are more frequently used by the Mexican duck will allow developing strategies for their conservation and sustainable use.
Prosopis laevigata and Mimosa biuncifera are frequently found in arid and semiarid shrublands, bu... more Prosopis laevigata and Mimosa biuncifera are frequently found in arid and semiarid shrublands, but scarce information is available about their influence on plant community structure and soil fertility. We compared plant community structure, diversity and soil nutrients of three semiarid shrubland sites located in Mezquital Valley, Mexico. These sites differ in their dominant species: Site 1 (Bingu) P. laevigata, Site 2 (González) M. biuncifera, and Site 3 (Rincón) with the presence of both legumes. The results showed that the plant community with P. laevigata and M. biuncifera (Site 3) had more cover, taller plants and higher plant diversity than sites with only one legume (Site 1 and Site 2). Soil organic matter (SOM), soil organic carbon (SOC), total nitrogen (TN), phosphorus-Olsen (P) and C mineralization were higher in the soil under the canopy of both legumes than in bare soil. In contrast, soil cation concentrations were lower under the canopy of P. laevigata, but not for M. biuncifera. In addition, the density of arbuscular mycorrhizal fungi spores was higher within the soil under the canopy of M. biuncifera than in the soil under the canopy of P. laevigata. Thus, resource islands (RI) created by P. laevigata increased the amounts of SOC, TN and P when compared with the RI of M. biuncifera. This study provided evidences about the importance of species identity in order to expand the niche availability for the establishment of other plants, and highlights that P. laevigata and M. biuncifera jointly influencing plant colonization within semiarid ecosystems
Se estudió el proceso germinativo de tres especies de Cephalocereus (C. apicicephalium, C. nizand... more Se estudió el proceso germinativo de tres especies de Cephalocereus (C. apicicephalium, C. nizandensis, C. totolapensis) endémicas del Itsmo de Tehuantepec, Oaxaca, México, bajo las hipótesis de que las semillas perderán la capacidad germinativa a medida que pasen los días después de la recolección y que la germinación es diferente entre especies, pero no entre poblaciones de la misma especie. Para cada una de las especies estudiadas, se recolectaron semillas de poblaciones diferentes y se sembraron en cuatro fechas distintas, colocando 30 semillas en dos o tres cajas de Petri. Las cajas se colocaron en una cámara de ambiente controlado y la germinación se registró diariamente durante 30 días, considerando una semilla germinada cuando emergía la radícula. Los porcentajes de germinación (38.8% en C. totolapensis, 55.1% en C. apicicephalium) y la velocidad de germinación (1.6 en C. apicicephalium, Guiengola-2 a 24 en C. apicicephalium, Guiengola-1 y C. nizandensis, La Mata) fueron sig...
Fagus grandifolia subsp. mexicana is a species restricted to small populations under high anthrop... more Fagus grandifolia subsp. mexicana is a species restricted to small populations under high anthropogenic pressure. With the aim to attain information to propose conservation strategies of this species, the seed rain and demography of current-year seedlings were analyzed at La Mojonera, Hidalgo, Mexico. A 4 800 m 2 plot divided into 10 X 10 m quadrants was established. The seed
Canada, the United States and Mexico all have a Ion history of rangeland monitoring. However none... more Canada, the United States and Mexico all have a Ion history of rangeland monitoring. However none have developed a nationwi ? e database or even a standardized set of protocols. The lack of standardization, inadequately developed relationships between management objectives and monitoring protocols, and an emphasis on data collection rather than analysis and interpretation have limited the value of past
Natural regeneration of eight species of trees in three different types of gaps caused by selecti... more Natural regeneration of eight species of trees in three different types of gaps caused by selective logging of mahogany in a rainforest of Quintana Roo, Mexico, was studied. Point centered quarter method was applied randomly in each of the 10 replications per site. Height and density of the seedling