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78 resultados encontrados para: TEMA: Palinología
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Resumen en: Español |
Resumen en español

Here, we use 30 long-term, high-resolution palaeoecological records from Mexico, Central and South America to address two hypotheses regarding possible drivers of resilience in tropical forests as measured in terms of recovery rates from previous disturbances. First, we hypothesize that faster recovery rates are associated with regions of higher biodiversity, as suggested by the insurance hypothesis. And second, that resilience is due to intrinsic abiotic factors that are location specific, thus regions presently displaying resilience in terms of persistence to current climatic disturbances should also show higher recovery rates in the past. To test these hypotheses, we applied a threshold approach to identify past disturbances to forests within each sequence. We then compared the recovery rates to these events with pollen richness before the event. We also compared recovery rates of each site with a measure of present resilience in the region as demonstrated by measuring global vegetation persistence to climatic perturbations using satellite imagery. Preliminary results indeed show a positive relationship between pre-disturbance taxonomic richness and faster recovery rates. However, there is less evidence to support the concept that resilience is intrinsic to a region; patterns of resilience apparent in ecosystems presently are not necessarily conservative through time.


2.
- Artículo con arbitraje
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Resumen en: Español | Inglés |
Resumen en español

La miel es un producto alimenticio con alto valor nutricional y potencial farmacológico. La mayoría de los estudios de este producto se han centrado en las propiedades de la miel producida por Apis mellifera, que se ha utilizado en medicina alternativa, destacando por sus actividades antioxidantes, antimicrobianas y antiinflamatorias, entre otras. En este trabajo, se identificó el origen floral, la concentración de proteína soluble, los compuestos fenólicos y la actividad antioxidante y quelante de metales de las mieles producidas por Melipona beecheii y Frieseomelitta nigra,originarias de San Marcos, comunidad de Tenosique en Tabasco, México. Los resultados muestran que la miel producida por F. nigra es de origen polifloral derivada principalmente de la especie Piper sp., Aff. Brosimum, Asteraceae, Ziziphus sp., Haematoxylum campechianum, mientras que la producida por M. beecheii fue monofloral (Eugenia sp.). La miel de F. nigra presentó mayor concentración de compuestos fenólicos y mayor efectividad para atrapar los radicales superóxido y DPPH, además de un mejor potencial de quelación del cobre. Por su parte, la miel de M. beecheii presentó mayor capacidad de captación de los radicales ABTS y quelación del hierro; mientras que la capacidad de absorción del radical hidroxilo fue similar para ambas mieles. Este trabajo resalta la importancia de contar con análisis palinológicos y bioquímicos sobre las mieles de las abejas nativas sin aguijón por el potencial terapéutico que tienen y de las cuales, en el caso de algunas especies, no se tiene información.

Resumen en inglés

Honey is a food product with high nutritional and pharmacological value. Most studies of this product have focused on studying the properties of honey produced by Apis mellifera, which has been used in alternative medicine, highlighting the antioxidant, antimicrobial and anti-inflammatory activities, among others. In this work, we identified the floral origin, the concentration of soluble protein and phenolic compounds, and we assessed the antioxidant and chelating activity of the honey produced by Melipona beecheii and Frieseomelitta nigra from the community of San Marcos in Tenosique, Tabasco, México. The results show that the honey produced by M. beecheii was of monofloral origin (Eugenia sp.); while that of F. nigra is of polyfloral origin, derived mainly from the species Piper sp., Aff. Brosimum, Asteraceae, Ziziphus sp., Haematoxylum campechianum). Honey produced by F. nigra show higher concentration of phenolic compounds, it is more effective in entrapping the DPPH and superoxide radicals, and exhibits better copper chelating potential. The honey of M. beecheii has a higher capacity for uptake of ABTS radicals and chelation of iron. The uptake capacity of the hydroxyl radical was similar for both honeys. This work highlights the importance of having palynological and biochemical analyzes on the honeys of native stingless bees, because of their therapeutic potential, where for many species there is a lack of information.


3.
- Capítulo de libro con arbitraje
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From Calakmul to the sea: the historical ecology of a classic maya city that controlled the Candelaria/Champoton watersheds
Gunn, Joel D. (autor) ; Folan Higgins, William J. (autor) ; Torrescano Valle, Nuria (autor) ; Faust, Betty (autora) ; Geovannini Acuña, Helga Z. (autora) ; Siemens, Alfred H. (autor) ;
Disponible en línea
Contenido en: The holocene and anthropocene environmental history of Mexico: a paleoecological approach on Mesoamerica / editors: Nuria Torrescano Valle, Gerald A. Islebe, Priyadarsi D. Roy Cham, Switzerland: Springer International Publishing, 2019 páginas 209-248 ISBN:978-3-030-31718-8
Bibliotecas: Campeche , Chetumal , San Cristóbal
Cerrar
SIBE Campeche
59785-30 (Disponible)
Disponibles para prestamo: 1
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SIBE Chetumal
59785-20 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
59785-10 (Disponible)
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Resumen en: Inglés |
Resumen en inglés

The Candelaria River watershed of Campeche, Mexico, and Petén, Guatemala, has shaped millennia of Maya, perhaps from their beginnings and generations of archaeologists. This chapter reviews efforts to understand Candelaria historical ecology over the past four decades, mostly in the northern branch, the Candelaria-El Caribe-Tomatillal system, as it relates to the cities of Calakmul and Uxul. Additional investigations stem from the river system farther north, the Champoton-Desempeño watershed, which also approaches Calakmul at its headwaters. Four other projects (Oxpemul, Yaxnohcah, Naachtun, Uxul) have emerged in the southern branches of the Candelaria and Desempeño in recent years, in addition to a long-standing project at El Mirador. Methods utilized range over global-local climate teleconnections, geology, ethnoecology, soil formation and transformation, geochemistry, pollen, and phytolith sampling. Brief but key statements of results for each method are reported as they contribute to a holistic perspective on the evolution and the death of Calakmul. Key interests that guided the research are the commercial location of the city and watershed in the Maya urban system, the way the watershed shaped the human settlement pattern in the west central Maya Lowlands, the socio-ecological adaptations over time, and its utility as a middle-level unit of study in links between human and Earth system changes. Finally, a nutrient flow model unifies the results into a concept that may yield deeper insights into the narrative and simulation modelling of Maya social evolution.


4.
Libro
The holocene and anthropocene environmental history of Mexico: a paleoecological approach on Mesoamerica / editors: Nuria Torrescano Valle, Gerald A. Islebe, Priyadarsi D. Roy
Torrescano Valle, Nuria (editora) ; Islebe, Gerald A. (editor) ; Roy, Priyadarsi Debajyoti (editor) ;
Cham, Switzerland : Springer International Publishing , c2019
Disponible en línea
Clasificación: EE/577 / H6
Bibliotecas: Campeche , San Cristóbal
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SIBE Campeche
ECO040007071 (Disponible)
Disponibles para prestamo: 1
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SIBE San Cristóbal
ECO010019867 (Disponible)
Disponibles para prestamo: 1
Resumen en español

This book provides essential information on Mexico’s Holocene and Anthropocene climate and vegetation history. Considering the geography of Mexico – which is home to a variety of climatic and environmental conditions, from desert and tropical to high mountain climates – this book focuses on its postglacial paleoecology and paleoclimatology. Further, it analyses human intervention since the middle Holocene as a major agent of environmental change. Offering a valuable tool for understanding past climate change and its relationship with present climate change, the book is a must-read for botanists, ecologists, palaeontologists and graduate students in related fields.

Índice

1 Introduction: The Holocene and Anthropocene Environmental History of Mexico
References
2 Paleoclimate of the Gulf of California (Northwestern Mexico) During the Last 2000 Years
Introduction
Regional Settings
Processes Responsible for the Sedimentation Cycle
Hydrological Processes Linked to Climate and Anthropogenic Changes
Integrated Water–Vertical Settling Studies in the Alfonso Basin
Climate Variations: Interannual, Centennial, and Millennial Scales
Centennial–Scale Variability
Climate Modeling
Conclusions
References
3 Holocene Hydroclimate of the Subtropical Mexico: A State of the Art
Introduction
Modern Climate
Register and Hypothesis
Vegetation Composition
Hydrological Variation and Climate Forcing
Conclusions
References
4 The Environment of Ancient Cloud Forests in the Mexican Pacific
The Mexican Pacific
The Past Environments in the Mexican Pacific
The Present Cloud Forest
The Ancient Cloud Forests
Methods
Results
Discussion
Conclusion
References
5 Sea Level Change and Its Influence on the Coastal Landscape in the Gulf of Mexico During the Holocene
Introduction
Vegetation Types in the Gulf of Mexico
Vegetation Response to Sea Level
Human Impact on Coastal Vegetation
Conclusion
References
6 Insights into the Holocene Environmental History of the Highlands of Central Mexico
Introduction
Central Mexico
Holocene Environment
References
7 Integration of Landscape Approaches for the Spatial Reconstruction of Vegetation
Introduction
Methods
Results
Discussion
References
8 Volcanic Activity in Mexico During the Holocene
Introduction
Distribution of Volcanoes in Mexico
Holocene Eruptions from Volcanoes in Mexico
Active Stratovolcanoes and Calderas
Monogenetic Volcanic Fields
Outlook of Holocene Volcanism
References


5.
- Capítulo de libro con arbitraje
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Human influence versus natural climate variability
Torrescano Valle, Nuria (autora) ; Ramírez Barajas, Pablo Jesús (autor) ; Islebe, Gerald A. (autor) ; Vela Pelaez, Alejandro Antonio (autor) ; Folan Higgins, William J. (autor) ;
Disponible en línea
Contenido en: The holocene and anthropocene environmental history of Mexico: a paleoecological approach on Mesoamerica Cham, Switzerland : Springer International Publishing, 2019 página 171-194 ISBN:978-3-030-31718-8
Bibliotecas: Campeche , Chetumal , San Cristóbal
Cerrar
SIBE Campeche
59783-30 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
59783-20 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
59783-10 (Disponible)
Disponibles para prestamo: 1
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Resumen en español

This chapter discusses past climate change drivers and ecological responses in southeastern Mexico. Ancient human influence on ecosystems is evident from sediment cores. Past human activities are evident in fossil records but make the interpretation of the past climatic signals more difficult. Conversely the human signal provides important evidence for understanding the level of human impact on the climate system and ecosystems. Four sediment cores at different locations of the Yucatán Peninsula were analyzed for fossil pollen and geochemistry. Human-induced ecological change was evaluated compared to climate-driven environmental change. Fossil pollen gave a clear signal of landscape and precipitation change in the Preclassic and Classic periods. The geochemical ratios provided evidence of local and regional hydrological change. The Chumpich Lake registry reveals that the management of low forests was efficient and indicates good hydrological control in the landscape. However this evidence is different in other sites from Yucatán Peninsula with deficient erosion control. Probably due to the differential climate response in the Chumpich–Uxul region, the drought was not as drastic as in other places.


6.
- Artículo con arbitraje
Análisis palinológico de la miel de Apis mellifera L., producida en el altiplano del estado de Puebla, México
Pérez Sato, Marcos ; Flores Garrido, A. F. (coaut.) ; Castro González, N. P. (coaut.) ; Escobar Hernández, R. (coaut.) ; Soni Guillermo, E. (coaut.) ; Pérez Hernández, Hermes (coaut.) ;
Contenido en: Agro Productividad Año 11, Vol. 11, no. 3 (marzo 2018), p. 98-103 ISSN: 2395-9185
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Resumen en: Español | Inglés |
Resumen en español

Se realizó un estudio palinológico con el objetivo de analizar la miel de Apis mellifera L., producida en la región altiplano del estado de Puebla y determinar su origen botánico, índices de diversidad y equidad, hábito de pecoreo y estrato vegetal de importancia, para lo cual se recolectaron nueve muestras directamente de los tanques de sedimentación de miel, así como flores en la proximidad de los apiarios en siete municipios de dicha región. Los granos de polen contenidos en 10 g de miel en cada muestra fueron extraídos por centrifugación, tratados por acetólisis y montados en gelatina glicerada. Se encontraron 51 tipos polínicos, de los cuales, sólo cuatro son considerados de importancia pertenecientes a las especies Brassica spp., y Lopezia spp.; a la familia Asteraceae y un tipo polínico desconocido. Las mieles fueron clasificadas como monoflorales de Asteraceae excepto la proveniente de San Salvador el Seco, que se consideró como multifloral con predominancia de Asteraceae. El índice de diversidad fue en un rango de 1.23 a 2.00, con una media de 1.590.3 considerado bajo en comparación con lo registrado en zonas tropicales. El índice de equidad se ubicó entre 0.46 y 0.76, con una media de 0.580.1, lo que concuerda con el aprovechamiento de un reducido número especies. El estrato vegetal de importancia fue el herbáceo, y sólo en una muestra un tipo polínico estuvo representado por más del 70%, que determina un hábito de pecoreo poliléctico con fuerte preferencia por la familia Asteraceae.

Resumen en inglés

A palynology study was carried out with the objective of analyzing honey from Apis mellifera L., produced in the high plateau region of the state of Puebla and defining its botanical origin, indexes of diversity and equity, foraging habit, and plant stratum of importance, for which nine samples were collected directly from the honey sedimentation tanks, as well as flowers in the proximity of apiaries in seven municipalities of that region. The pollen grains contained in 10 g of honey in each sample were extracted through centrifugation, treated by acetolysis and mounted on glycated gel. Fifty-one (51) pollen types were found, of which only four are considered important, belonging to the species Brassica spp. and Lopezia spp., to the family Asteraceae, and one unknown pollen type. The honeys were classified as monofloral from Asteraceae except the one from San Salvador el Seco, which was considered multifloral with predominance of Asteraceae. The diversity index was in a range of 1.23 to 2.00, with a mean of 1.590.3 considered low in comparison to what is found in tropical zones. The equity index was placed between 0.46 and 0.76, with a mean of 0.580.1, which agrees with the exploitation of a reduced number of species. The important plant stratum was the herbaceous, and only in one sample of pollen type was represented by more than 70 %, which determines a polylectic foraging habit with strong preference for the Asteraceae family.


7.
- Capítulo de libro con arbitraje
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Characterization of Scaptotrigona mexicana Pot-Pollen from Veracruz, Mexico
Contreras Oliva, Adriana (autora) ; Pérez Sato, Juan Antonio (autor) ; Gómez Merino, Fernando Carlos (autor) ; López Garay, Luz Anel (autora) ; Villanueva Gutiérrez, Rogel (autor) ; Crosby Galván, María Magdalena (autora) ; Trejo Téllez, Libia Iris (autora) ;
Disponible en línea
Contenido en: Pot-pollen in stingless bee melittology / Patricia Vit, Silvia R.M. Pedro, David W. Roubik, editors Cham, Switzerland, German : Springer International Publishing AG, 2018 p. 325-337 ISBN:978-3-319-61838-8 :: 978-3-319-61839-5 (eBook)
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8.
- Artículo con arbitraje
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Holocene precipitation changes in the Maya forest, Yucatán peninsula, Mexico
Vela Pelaez, Alejandro Antonio ; Torrescano Valle, Nuria (coaut.) ; Islebe, Gerald A. (coaut.) ; Mas, Jean François (coaut.) ; Weissenberger, Holger (coaut.) ;
Contenido en: Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 505 (September 2018), p. 42-52 ISSN: 0031-0182
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Resumen en: Inglés |
Resumen en inglés

Holocene fossil pollen samples (n=38) from Lake Silvituc in Mexico were analyzed with the analog technique using modern pollen samples (n=98) of the Yucatán Peninsula, Mexico. Calculated dissimilarity indices allow us to reconstruct the vegetation and to develop a precipitation record for the last 7900 years. The Middle Holocene shows a gradual increase of precipitation and a marked drop in reconstructed precipitation around 4200 BCE. During the Late Holocene two phases were identified: Phase I (2500 BCE – 1 CE) shows the greatest increase in precipitation with four peaks around 1200 BCE, 650 BCE, 200 BCE and 1 CE. Also a period of increased precipitation resulted for the period between 200 and 500 BCE. Periods of reduced precipitation were detected at 900–1100 BCE, 500–600 BCE and 100–190 BCE. Phase II (1–2000 CE) encompasses several strong dry events during the following periods: 150–300 CE, 750–900 CE, 1050–1180 CE, and 1530–1580 CE. A strong reduction of 32% in precipitation in the late Preclassic Period (100–300 CE) was detected. Non-analogs of Phase II are associated with periods of reduced precipitation and fall into time periods of extended droughts related to the Maya Late Classic and the Little Ice Age. A limiting factor on the use of analogs for tropical forests is that a combination of different analogs for the same fossil pollen signal exists. Interpretation under these circumstances requires good knowledge of the ecology of the taxa and a priori characterization of the modern samples.


9.
- Tesis
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Influencia de tres compuestos volátiles emitidos por las anteras de Solanum rostratum en la preferencia del polinizador Bombus impatiens / Jesús Fernándo García Crisóstomo
García Crisóstomo, J. F ; Solís Montero, Lislie (director) ; Alavez Rosas, David (asesor) ; Cruz López, Leopoldo Caridad (asesor) ;
Tapachula, Chiapas, México : Universidad Autónoma de Chiapas. Instituto de Biociencias , 2018
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Resumen en: Español |
Resumen en español

Las plantas emiten una serie de compuestos volátiles a través de diversas estructuras florales (glándulas secretoras) o por difusión de los tejidos florales. En algunas angiospermas, las anteras y/o los granos de polen son los responsables de la emisión de volátiles. Se usó como modelo de estudio a Solanum rostratum, una especie con anteras dimorficas (anteras polinizadoras y alimenticias), que ofrece granos de polen como recompensa para los polinizadores y emite un olor similar al durazno. Se sabe que esta planta emite compuestos volátiles, sin embargo, se desconoce la influencia de algunos compuestos en la atracción de los polinizadores. El objetivo de esta investigación es evaluar la preferencia de B. impatiens por los compuestos volátiles emitidos por las anteras de S. rostratum. Se realizaron extractos de granos de polen y de anteras vacías, posteriormente se realizaron análisis y se determinaron las concentraciones de los compuestos de interés. Finalmente se realizaron bioensayos con extractos y compuestos sintéticos en forma individual y en mezclas, en un olfatómetro “Y”. Como resultado se observó mayor preferencia de Bombus impatiens por los compuestos emitidos por las anteras alimenticias en comparación con las anteras polinizadoras. En conclusión los compuestos volátiles de S. rostratum no son emitidos por los granos de polen, sin embargo, si se producen en las anteras a través de osmóforos en ambos tipos de anteras, siendo los compuestos volátiles emitidos por las anteras alimenticias más atractivos en la preferencia de B. impatiens, en comparación con los compuestos emitidos por las anteras polinizadoras.


10.
- Artículo con arbitraje
The Paleoanthropocene of the Yucatán Peninsula: palynological evidence of environmental change
Islebe, Gerald A. ; Torrescano Valle, Nuria (coaut.) ; Aragón Moreno, Alejandro Antonio (coaut.) ; Vela Peláez, Alejandro A. (coaut.) ; Valdéz Hernández, Mirna (coaut.) ;
Contenido en: Boletín de la Sociedad Geológica Mexicana Vol. 70, no. 1 (March 2018), p. 49-60 ISSN: 1405-3322
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Resumen en: Español | Inglés |
Resumen en español

Las actividades humanas han influenciado sobre los paisajes de la península de Yucatán desde más de 4000 años. Varios estudios paleoecológicos muestran actividades de agricultura, el registro polínico más antiguo de maíz (Zea mays L.) proviene del norte de Belice, con una edad aproximada de 3300 BC. Otros estudios paleoecológicos del norte de Guatemala y de la porción mexicana de la península de Yucatán muestran registros de maíz fósil con rangos de edad desde 1500 a 3000 A.C. La mayoría de los registros muestran una marcada tendencia a condiciones de mayor sequía después de los 3500 A.C. Estas tendencias de sequía se registran como reducción del polen fósil arbóreo. El registro polínico de Z. mays está acompañado de taxa que indican diferentes grados de perturbación en la vegetación natural.

Resumen en inglés

Human activities have changed and shaped landscape conditions of the Yucatán Peninsula for more than 4000 years. Several paleoecological studies showed the oldest pollen record of corn-based agriculture is from northern Belize, with an estimated age of 3300 BC. Several other studies report maize between 1500 and 3000 BC from northern Guatemala and the Mexican part of the Yucatán Peninsula. After 3500 cal yr BP several paleoecological studies showed a marked tendency to drier climatic conditions. In pollen records, increased drought is expressed as a reduced presence of fossil arboreal pollen. Pollen records with the presence of Zea mays also show other taxa, which are indicators of disturbance in different vegetation types.