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100 resultados encontrados para: TEMA: Factores ambientales
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12.
- Artículo con arbitraje
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Distribution and Abundance of Big-Leaf Mahogany (Swietenia macrophylla) on the Yucatan Peninsula, Mexico
Navarro Martínez, María Angélica (autora) ; Ellis, Edward Alan (autor) ; Hernández Gómez, Irving Uriel (autor) ; Romero Montero, José Arturo (autor) ; Sánchez Sánchez, Odilón Manuel (autor) ;
Contenido en: Tropical Conservation Science Vol. 11 (2018), p. 1–17 ISSN: 1940-0829
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Resumen en: Inglés |
Resumen en inglés

Big-leaf mahogany (Swietenia macrophylla King) is an economically important timber species in the Neotropics. For over three centuries, it has been selectively extracted from tropical forests, threatening its populations. We investigate the actual and potential distribution of big-leaf mahogany and assess its abundance on the Yucatan Peninsula based on the National Forest and Soils Inventory database. Furthermore, we evaluate environmental factors associated with its distribution, abundance, and tree size. The actual and potential distribution models show the presence of mahogany in a wide geographic area covering the southern and eastern portions of the Yucatan Peninsula. Abundance of mahogany in the landscape varies and in general is low. The spatial potential distribution model was best explained by the environmental variables of vegetation cover (medium- and high-stature semievergreen tropical forest) and elevation (upland areas). Results also indicate that mahogany remains relatively abundant and contain larger size classes in localities where the species has been harvested and managed for decades under community forest management. Furthermore, statistical analyses show greater tree density of mahogany mostly associated with low-stature semievergreen tropical forest having deep soils (gleysols and vertisols), while larger tree size (diameter at breast height) was associated with medium-stature semievergreen tropical forests in upland areas with moderately deep or shallow soils (mostly rendzinas or leptosols). Despite deforestation, land-use change and forestry activities on the Yucatan Peninsula, particularly in the past 20 years, the distribution and abundance of mahogany do not appear to be as drastically reduced as described in other neotropical regions.


13.
- Artículo con arbitraje
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Evolutionary and food supply implications of ongoing maize domestication by Mexican campesinos
Bellon Corrales, Mauricio Rafael ; Mastretta Yanes, Alicia (coaut.) ; Ponce Mendoza, Alejandro (coaut.) ; Ortiz Santamaría, Daniel (coaut.) ; Oliveros Galindo, Oswaldo (coaut.) ; Perales Rivera, Hugo Rafael (coaut.) ; Acevedo, Francisca (coaut.) ; Sarukhán Kermez, José (coaut.) (1940-) ;
Contenido en: Proceedings of the Royal Society B: Biological Sciences Vol. 285, no. 1885 (August 2018), p. 48-57 ISSN: 0962-8452
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Resumen en: Inglés |
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Maize evolution under domestication is a process that continues today. Case studies suggest that Mexican smallholder family farmers, known as campesinos, contribute importantly to this, but their significance has not been explicitly quantified and analysed as a whole. Here, we examine the evolutionary and food security implications of the scale and scope under which campesinos produce maize. We gathered official municipal-level data on maize production under rainfed conditions and identified campesino agriculture as occurring in municipalities with average yields of less than or equal to 3 t ha-¹. Environmental conditions vary widely in those municipalities and are associated with a great diversity of maize races, representing 85.3% of native maize samples collected in the country. We estimate that in those municipalities, around 1.38 10¹¹ genetically different individual plants are subjected to evolution under domestication each season. This implies that 5.24 108 mother plants contribute to the next generation with their standing genetic diversity and rare alleles. Such a large breeding population size also increases the total number of adaptive mutations that may appear and be selected for. We also estimate that campesino agriculture could potentially feed around 54.7 million people in Mexico. These analyses provide insights about the contributions of smallholder agriculture around the world.


14.
- Artículo con arbitraje
Mangrove productivity and phenology in relation to hydroperiod and physical–chemistry properties of water and sediment in Biosphere Reserve, Centla Wetland, Mexico
Torres Velázquez, Jony Ramiro ; Barba Macías, Everardo (coaut.) ; Choix, Francisco J. (coaut.) ;
Contenido en: Tropical Conservation Science Vol. 11 (October 2018) p. 1-14 ISSN: 1940-0829
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Resumen en: Inglés |
Resumen en inglés

Mangrove is the dominant vegetation in the estuaries, river deltas, and coastal lagoons of tropical and subtropical regions. A number of factors affect the structure and productivity of mangrove forests, including hydrology, soil salinity, and soil type. In this study, litter production in the Centla Wetland Biosphere Reserve in Tabasco, Mexico, was evaluated as a function of the physical–chemical properties of water and sediments. The study cycle was from June 2015 to June 2016. Litterfall was measured, and water samples were collected at the surface, interstitial, and subterranean level to estimate the physical– chemical parameters. Sediment samples were also collected to determine the texture, pH, organic matter, bulk density, and moisture content. The mangrove was composed of Rhizophora mangle (L.), Laguncularia racemosa (L.) Gaertn, and Avicennia germinans (L.) Stearn. The pH was presented in a range of 5.3 to 7.4, and spatially, the texture of sediment varied significantly, with high values of sand in Playa (73.7% 3.4%) and high content of clay (57.2% 1.4%) and organic matter (41% 2% average) in mangrove riverine type. The highest salinity of interstitial water was encountered at Beach (29 3.0 PSU) and of groundwater (36.4 1.5 PSU). Overall, the average estimated litter fall was 10.45 tonha 1 year 1 . These results indicate that the litter production is related to the response of the mangrove to the variation of the environmental conditions of each site (substrate texture, hydroperiod, soil moisture, water salinity, water redox potential, and soil organic matter).


15.
Libro
De montaña a reserva forestal: colonización, sentido de comunidad y conservación en la Selva Lacandona / Ingreet Juliet Cano Castellanos
Cano Castellanos, Ingreet Juliet (autora) ;
Ciudad de México, México : Universidad Nacional Autónoma de México. Instituto de Investigaciones Sociales , 2018
Clasificación: CH/972.75 / C36
Bibliotecas: San Cristóbal , Tapachula
Cerrar
SIBE San Cristóbal
ECO010019840 (Prestado)
Disponibles para prestamo: 0
Cerrar
SIBE Tapachula
29332-20 (Disponible)
Disponibles para prestamo: 1
Índice | Resumen en: Español |
Resumen en español

La relación entre las comunidades campesinas y los ecosistemas suscita enconados debates entre académicos, organizaciones no gubernamentales y funcionarios ambientales, además de una amplia bibliografía. Con este libro se hace una aportación muy importante al debate. Resulta, además, ejemplar en más de un sentido porque muestra que la antropología contemporánea ofrece las mejores herramientas para comprender dicha relación, pero sobre todo porque va más allá de su referencia al sureste mexicano, haciendo comprensible la complejidad, las contradicciones y los desafíos de la conservación ecológica. Antonio Azuela de la Cueva La autora de esta obra posee una nítida mirada etnográfica y una admirable sensibilidad histórica. En este novedoso estudio nos explica cómo la aparente voluntad local de conservar las selvas a través de “dispositivos de poder”, entre los que sobresale la certificación gubernamental, es una evidencia de la “coproducción” del Estado desde el nivel local, y no necesariamente un indicador de las capacidades locales para generar un exitoso manejo de los recursos forestales de propiedad comunal. Esta es una lectura imprescindible para los interesados en temas socioambientales analizados desde su verdadero contexto político.

Índice

Introducción
Primera parte
Imágenes de la tierra y la montaña
Introducción
La tierra que nos vio crecer
Partir y llegar a una tierra evocadora de sueños e incertidumbres
La abundancia, la escasez y otras expresiones de interacción con la montaña
Segunda parte
El sentido de comunidad en tierras de montaña Introducción
“Hacer el ejido” en la montaña. Experiencias de apropiación de la figura ejidal
“Sacar adelante el ejido”. Divergencias y consensos frente al manejo del territorio
Ejido y sentido de comunidad desde la trayectoria individual y familiar
Tercera parte
De montaña a “reserva forestal”
Introducción
La producción de la conservación ecológica en la selva Lacandona
Orientar el sentido de comunidad al tema de la conservación
“Reservas forestales ejidales”: de proyecto a realidad pública y oficial
Conclusiones
Anexo 1. Mapas
Anexo 2. Artículo periodístico
Anexo 3. Certificado de ANP de las guacamayas
Bibliografía


16.
Libro
Climate change and health of nations: famines, fevers, and the fate of populations / Anthony J. McMichael with Alistair Woodward and Cameron Muir
McMichael, Anthony J. (autor) (1942-2014) ; Woodward, Alistair (autor) ; Muir, Cameron ;
New York, New York, United States : Oxford University Press , 2017
Clasificación: 304.25 / M3
Bibliotecas: Campeche
Cerrar
SIBE Campeche
ECO040007078 (Disponible)
Disponibles para prestamo: 1
Índice | Resumen en: Inglés |
Resumen en inglés

When we think of "climate change," we think of man-made global warming, caused by greenhouse gas emissions. But natural climate change has occurred throughout human history, and populations have had to adapt to the climate's vicissitudes. Anthony J. McMichael, a renowned epidemiologist and a pioneer in the field of how human health relates to climate change, is the ideal person to tell this story. Climate Change and the Health of Nations shows how the natural environment has vast direct and indirect repercussions for human health and welfare. McMichael takes us on a tour of human history through the lens of major transformations in climate. From the very beginning of our species some five million years ago, human biology has evolved in response to cooling temperatures, new food sources, and changing geography. As societies began to form, they too adapted in relation to their environments, most notably with the development of agriculture eleven thousand years ago. Agricultural civilization was a Faustian bargain, however: the prosperity and comfort that an agrarian society provides relies on the assumption that the environment will largely remain stable. Indeed, for agriculture to succeed, environmental conditions must be just right, which McMichael refers to as the "Goldilocks phenomenon." Global warming is disrupting this balance, just as other climate-related upheavals have tested human societies throughout history. As McMichael shows, the break-up of the Roman Empire, the bubonic Plague of Justinian, and the mysterious collapse of Mayan civilization all have roots in climate change.

Why devote so much analysis to the past, when the daunting future of climate change is already here? Because the story of mankind's previous survival in the face of an unpredictable and unstable climate, and of the terrible toll that climate change can take, could not be more important as we face the realities of a warming planet. This sweeping magnum opus is not only a rigorous, innovative, and fascinating exploration of how the climate affects the human condition, but also an urgent call to recognize our species' utter reliance on the earth as it is.

Índice

List of illustrations
Preface
Acknowledgements
1. Introduction
2. A Restless Climate
3. Climatic choreography of health and disease
4. From Cambrian Explosion to first farmers: how climate made us human
5. Spread of farming, new diseases, and rising civilisations: Mid-Holocene Optimum, 6,000 BCE to 3,000 BCE
6. Eurasian Bronze Age: unsettled climatic times
7. Romans, Mayans and Anasazi: the Classical Optimum to droughts in the Americas, 300 BCE to 1250 CE
8. Little Ice Age: Europe, China and beyond
9. Weather extremes, famine and disease in modern times (1800- 2000 CE)
10. The Holocene climate: fickle friend and foe
11. Facing the Future
Notes
Index


17.
Tesis - Maestría
Desafíos socio-ambientales y uso de agroquímicos en la región cañera de Río Hondo en el sur de México / Ana Cecilia Iuit Jiménez
Iuit Jiménez, Ana Cecilia (autora) ; García Ortega, Martha (directora) ; Alayón Gamboa, José Armando (asesor) ; Marín Poot, Héctor Manuel (asesor) ;
Chetumal, Quintana Roo, México : El Colegio de la Frontera Sur , 2017
Clasificación: TE/338.173610972 / I9
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
ECO030008643 (Disponible)
Disponibles para prestamo: 1
PDF
Índice | Resumen en: Español |
Resumen en español

El cultivo de la caña de azúcar ha estado estrechamente ligado al desarrollo de la economía mundial desde su implementación y expansión en las actuales Antillas y en el continente americano en un proceso que inició en el siglo XV. La Organización de las Naciones Unidas para la Educación, la Ciencia y la Cultura (UNESCO) consideró a este cultivo como el más importante del orbe ya a principios del siglo XIX a partir de que el azúcar, junto con el pan, la sal y el vino, fue uno de los componentes básicos de la dieta humana (SKIL, 2015). La historia acerca del gusto por el sabor dulce derivado de esta gramínea y la atribución de propiedades energéticas, como lo documenta Mintz (1996), enseña que los hábitos apegados a este producto y luego su consumo masivo impulsó el crecimiento del cultivo a nivel mundial en un proceso que se consolidó en medio milenio. Sin embargo, Rodríguez (2014) menciona que desde el establecimiento de la caña en el continente americano este cultivo ha requerido de apoyos extraeconómicos para funcionar, lo cual fue patente en el esquema colonial. Todo lo que los productores cañeros (colonizadores) compraban: insumos agrícolas y semillas, instrumentos y máquinas (para procesar el azúcar), fuerza de trabajo (esclavos africanos) y alimentos (ya que los cultivos de caña dejaban poco espacio para otros cultivos), se transportaba por vía marítima, lo que resultaba oneroso. Así, muchas mercancías eran traídas a precios elevados de las metrópolis y los cada vez más importantes puertos de los imperios de Europa.

A pesar de la gran inversión económica necesaria para esta gran empresa imperial, el cultivo de la caña de azúcar aumentó paulatinamente. En esa carrera productiva, entre 9 los siglos XV y XXI esta planta se distribuyó por la geografía tropical en los archipiélagos caribeños como en el continente. En ese proceso disminuyeron grandes áreas de bosques y selvas domesticando paisajes de tal manera que el sistema productivo de la caña de azúcar crea su propia ecología alrededor del sitio donde es instalado, lo que genera pérdida de suelos entre otros impactos (Rodríguez, 2014).

Índice

Introducción
El agroecosistema caña de azúcar
Importancia socio-económica del cultivo de caña en México
Uso de agroquímicos en el cultivo de la caña de azúcar
Afectaciones de los agroquímicos a la salud humana y al ambiente
Legislación internacional y nacional sobre agroquímicos
Vulnerabilidad del sector agrícola al cambio climático
El cultivo de la caña de azúcar y el cambio climático
La región cañera de Río Hondo, Quintana Roo
Artículo
Conclusiones generales
Literatura citada


18.
Artículo
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Skin parasitism by Paratrichosoma recurvum in wild American crocodiles and its relation to environmental and biological factors
Charruau, Pierre Alexandre Rémy Robert (autor) ; Pérez Flores, Jonathan Sechaly (autor) ; Labarre, Didier (autor) ;
Contenido en: Vol. 122, no. 3 (January 2017), p. 205-211 ISSN: 0177-5103
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Resumen en: Inglés |
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Paratrichosma spp. are capillarid worms that parasitize the abdominal skin of crocodiles. They are likely not a threat to crocodiles' health, but they affect the skins' commercial value. No successful treatment exists against this parasite, and present knowledge of its life cycle is limited. Herein we report new information on Paratrichosoma recurvum occurrence in wild American crocodiles Crocodylus acutus from Mexican Caribbean islands and its relation to environmental (water salinity, temperature, climatic events) and biological (body condition) factors. The percentage of parasitized crocodiles (30.3%) is among the highest recorded in wild crocodilian populations. Small (<40.8 cm total length [TL]) and large (>270 cm TL) crocodiles are less parasitized, probably due to the characteristics of their skin or of the parasite life cycle. Two individuals appeared to have eliminated worms naturally between their capture and recapture. The thorax-abdomen is the most parasitized area of the body of crocodiles. The risk of infection is not associated with the sex of the crocodile, but there was a difference in the proportion of parasitized crocodiles between sites, which could be related to different environmental conditions. The body condition of a crocodile does not seem to be affected by the parasite. Climatic events and water temperature show no effect on the parasitism of crocodiles, but salinity could have an effect. The infection of crocodiles by P. recurvum could depend more on an individual's behavior than on environmental conditions.


19.
Libro
*En proceso técnico. Solicítelo con la bibliotecaria de SIBE-Tapachula
The urban forest: cultivating green infraestructure for people and the environmental / David Pearlmutter, Carlo Calfapietra, Roeland Samson, Liz O´ Brien, Silvija Krajter Ostoic, Giovanni Sanesi, Rocio Alonso del Amo, editores
Pearlmutter, David (ed.) ; Calfapietra, Carlo (coed.) ; Samson, Roeland (coed.) ; Brien, Liz O´ (coed.) ; Krajter Ostoic, Silvija (coed.) ; Sanesi, Giovanni (coed.) ; Alonso del Amo, Rocio (coed.) ;
Cham, Switzerland : Springer , c2017
Clasificación: 635.977 / U7
Bibliotecas: Tapachula
Cerrar
SIBE Tapachula
ECO020013872 (Disponible)
Disponibles para prestamo: 1
Nota: En proceso técnico. Solicítelo con la bibliotecaria de SIBE-Tapachula
Resumen en: Inglés |
Resumen en inglés

This book focuses on urban "green infrastructure" the interconnected web of vegetated spaces like street trees, parks and peri-urban forests that provide essential ecosystem services in cities. The green infrastructure approach embodies the idea that these services, such as storm-water runoff control, pollutant filtration and amenities for outdoor recreation, are just as vital for a modern city as those provided by any other type of infrastructure. Ensuring that these ecosystem services are indeed delivered in an equitable and sustainable way requires knowledge of the physical attributes of trees and urban green spaces, tools for coping with the complex social and cultural dynamics, and an understanding of how these factors can be integrated in better governance practices. By conveying the findings and recommendations of COST Action FP1204 GreenInUrbs, this volume summarizes the collaborative efforts of researchers and practitioners from across Europe to address these challenges.


20.
Artículo
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Circular distribution of three species of epiphytic orchids in shade coffee plantations, in Soconusco, Chiapas, Mexico
García González, Alfredo ; Damon, Anne Asbhy (coaut.) ; Riverón Giró, Frander Brian (coaut.) ; Ávila Díaz, Irene (coaut.) ;
Contenido en: Plant Ecology and Evolution Vol. 149, no. 2 (July 2016), p. 189-198 ISSN: 2032-3921
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Resumen en: Inglés |
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Background and aims – Cardinal orientation of individuals is one of the least known and understood ecological or demographic factor governing the dynamics of epiphytic orchid populations. The circular distribution of three epiphytic orchids, Oncidium poikilostalix, Oncidium guatemalenoides and Lepanthes acuminata, was studied in shaded coffee plantations in the region of Soconusco, Chiapas, Mexico. A preference for a certain cardinal orientation on the phorophytes was analyzed, using circular statistics. Methods – Circular distribution tendencies were compared between the three species, two life stages (immatures and adults), and between the microsites (trunk, branch forks, branches, twigs) in which the individual orchids were distributed on the phorophytes. Results – Oncidium poikilostalix was the most abundant species (1,056 individuals). The three orchid species were found growing mainly on twigs of the coffee bushes. For populations in general, and for the life stages and microsites in particular, individuals of O. poikilostalix and O. guatemalenoides showed a preference for occupying the combination of the cardinal orientations south-southwest-west. Individuals of L. acuminata were orientated towards all eight cardinal points, with a slight numerical preference for east. Conclusions – Cardinal orientation of orchid species can be driven by specific climatic or ecological factors (e.g. direction and speed of prevailing winds; O. poikilostalix and O. guatemalenoides). These species may show clearer preferences for growing facing certain cardinal orientations. However, many species can be affected by a combination of microclimatic and ecological factors (e.g. humidity in the microenvironments, proximity to water sources, insolation, shade, competition or wind speed and direction; L. acuminata), which may influence at such a limited and local scale that orientation patterns may be difficult to detect.