Términos relacionados

145 resultados encontrados para: AUTOR: Islebe, Gerald A
  • «
  • 1 de 15
  • »
1.
Libro
Vegetation, phytogeography and paleo-ecology of the last 20,000 years of montane Central America / Gerald Alexander Islebe
Islebe, Gerald A. ;
Amsterdam : University of Amsterdam , s.f.
Clasificación: AC/581.5 / I5
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
ECO030000515 (Disponible)
Disponibles para prestamo: 1

PDF
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.


3.
Artículo
Anomalía climática medieval y la pequeña edad de hielo en Quintana Roo
Carrillo Bastos, Alicia (autora) ; Islebe, Gerald A. (autor) ; Ulanie Rosas, Chloe Brynie (autora) ; Villegas Sánchez, Carmen Amelia (autora) ;
Disponible en línea
Contenido en: AvaCiet Año 4, volumen 6, número 1 (enero-junio 2019), p. 95-105
PDF
Resumen en: Español | Inglés |
Resumen en español

En el presente estudio se analizan las señales en Quintana Roo, de eventos climáticos globales como la Anomalía Climática Medieval (ACM) y la Pequeña Edad de Hielo (PEH), a través de la comparación de registros sedimentarios de isótopos estables (δ18O/δ16O) y la relación de estos con teleconexiones y forzamientos climáticos por medio de la comparación de distintos sitios. La variabilidad climática fue inferida a partir de la relación de valores de isótopos estables de oxígeno (δ18O/δ16O) medida en la calcita de restos de organismos y a partir del porcentaje de titanio acumulado en sedimentos marinos. La Anomalía Climática Medieval y la Pequeña Edad de Hielo podrían estar vinculados a cambios en la irradiancia solar, las fases de El Niño-Oscilación del Sur y la migración de la Zona Intertropical de Convergencia (ITCZ). La discusión sugiere que las sequías en Quintana Roo ocurren durante fases de baja irradiancia solar, la condición tipo-Niño y la consecuente migración al Sur de la ITCZ. Durante las fases de mayor precipitación cuando la irradiancia solar aumenta, se presenta la condición tipo-Niña (fase negativa del ENSO) y la permanencia en el Norte de la ITCZ. Este mecanismo parece haber regulado el clima durante la ACM, en la cual se presentaron condiciones principalmente húmedas, mientras que en la PEH ocurrieron dos fases sostenidas de sequía.

Resumen en inglés

We analyze the expression of the global climatic events such as the Medieval Climatic Anomaly (ACM) and the Little Ice Age (PEH) in Quintana Roo by comparing stable isotope sedimentary records (δ18O / δ16O) and the relationship of those with teleconnections and climate forcing through the analysis of sediment cores from different sites. Climate variability has been inferred through the relationship of the value of the stable isotope of oxygen (δ18O/δ16O) that was measured from calcium carbonate of skeletal remains and from the percentage of titanium that accumulated in marine deposits offshore Venezuela. The Medieval Climatic Anomaly and the Little Ice Age could be linked to changes in the solar irradiance, the El Niño Southern Oscillation phases and the migration of the Intertropical Convergence Zone. The discussion suggests that dry conditions occur during phases of low solar irradiance, the El Niño-like condition and the consequent southward migration of the ITCZ. And the phases of greater precipitation when the solar irradiance increases, the La Niña-Like condition (negative phase of the ENSO) and the ITCZ is situated north of the Equator. This mechanism seems to have regulated the climate during the ACM, in which humid conditions dominated the Quintana Roo. During the PEH two protracted phases of drought occurred.


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
Cerrar
SIBE Campeche
ECO040007071 (Disponible)
Disponibles para prestamo: 1
Cerrar
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
*Solicítelo con su bibliotecario/a
Holocene paleoecology and paleoclimatology of South and Southeastern Mexico: a palynological and geospatial approach
Islebe, Gerald A. (autor) ; Carrillo Bastos, Alicia (autor) ; Aragón Moreno, Alejandro Antonio (autor) ; Valdéz Hernández, Mirna (autor) ; Torrescano Valle, Nuria (autor) ; Cabanillas Terán, Nancy (autora) ;
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 195-207 ISBN:978-3-030-31718-8
Bibliotecas: Campeche , Chetumal , San Cristóbal
Cerrar
SIBE Campeche
59784-30 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
59784-20 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
59784-10 (Disponible)
Disponibles para prestamo: 1
Nota: Solicítelo con su bibliotecario/a
Resumen en español

Reconstruction of Holocene paleoecological conditions and paleoclimate of an area with high biological diversity and a variety of climatic conditions like southern and southeastern Mexico is complex. This region is characterized by vegetation types ranging from tropical forest to high mountain vegetation. Additionally, this region was inhabited by the ancient Maya culture, which shaped the landscape for several millennia. Previous paleoecological studies from this region were focused on the Maya culture-environment relationships, to decipher natural and human-induced deforestation. These studies also aimed to understand the effects of climatic regional forcing (El Niño-Southern Oscillation (ENSO), Intertropical Convergence Zone (ITCZ), and North Atlantic Oscillation (NAO) on the natural vegetation. In this chapter we review the paleoecological results and present a new geospatial approach to analyze past precipitation and tropical forest distribution of the Yucatán Peninsula from 1 AD to 1700 AD in 100-year intervals. The geospatial analysis revealed heterogeneity in spatial patterns of precipitation and tropical forest extension during the Late Preclassic, Terminal Classic, and Medieval Warm Period to Little Ice Age transition. The dry periods of the Middle and Late Holocene in the Yucatán Peninsula and southern Mexico can be chronologically placed in the following intervals: 4700–3600 cal year BP, 3400–2500 cal year BP, 2300–2100 cal year BP, 1900–1700 cal year BP, 1400–1300 cal year BP, 730 cal year BP, and 560 cal year BP. We conclude that this region requires additional studies with strong chronological framework due to its heterogeneous environmental conditions.


6.
- Capítulo de libro con arbitraje
*Solicítelo con su bibliotecario/a
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
Nota: Solicítelo con su bibliotecario/a
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.


7.
- Capítulo de libro con arbitraje
*Solicítelo con su bibliotecario/a
Introduction: the holocene and anthropocene environmental history of Mexico
Torrescano Valle, Nuria (autora) ; Islebe, Gerald A. (autor) ; Roy, Priyadarsi Debajyoti (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 página 1-5 ISBN:978-3-030-31718-8
Bibliotecas: Campeche , Chetumal , San Cristóbal
Cerrar
SIBE Campeche
59782-30 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
59782-20 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
59782-10 (Disponible)
Disponibles para prestamo: 1
Nota: Solicítelo con su bibliotecario/a
Resumen en español

The Holocene spans the last 11,700 years of Earth’s history, and the paleoecology and paleoclimate dynamics of Mexico over this interval were complex. This is apparent when considering the region’s ecological and physiographic diversity, as well as human impact since the Late Holocene. The geography of Mexico varies from desert to high mountain systems, indicating conspicuous precipitation and temperature variability on latitudinal and altitudinal scales. More than one-third of Mexico’s territory is classified as arid or subarid. This area receives more than 60% of its total annual precipitation during the warm season through the North American Monsoon (NAM) and tropical storm systems, and significant winter precipitation occurs only in its northwestern margin. The Anthropocene is the latest part of the Holocene and it is marked by an era of substantial human activity. Climate change during this interval is not exclusively driven by natural processes, as humans have been influencing shifts in the global climate. Several climate projections predict that anthropogenic global warming will cause further enhancement in aridity in this drought-prone region by increasing the mean temperature and reducing the average annual rainfall in the near future. Other areas of Mexico are projected to receive less annual precipitation or the same amount but in shorter time periods. Ultimately, the knowledge of Holocene environmental change can provide society with clues for conservation, management, and adaptation of Mexico’s diverse environments.


PDF
Resumen en: Inglés |
Resumen en inglés

The role of invasive species in ecosystem functioning represents one of the mainchallenges in ecology.Pteridium aquilinumis a successful cosmopolitan invasive specieswith negative effects on the ecological mechanisms that allow secondary succession. Inthis study, we evaluated the influence of P. aquilinumon secondary succession underdifferent disturbances in a seasonal dry forest of the Yucatán Peninsula. We determined species richness, composition and the relative importance value in four sampling units. Fabaceae followed by Asteraceae, Meliaceae, Rubiaceae, Sapindaceae and Verbenaceaewere the most species rich families. A dissimilarity analysis determined significant differences in beta diversity between sampling units. With a generalized linear model wefound that species richness was best explained by site conditions, followed by calciumand soil organic matter. Also, the generalized linear model showed that abundanceresulted in a strong correlation with site conditions and soil characteristics. Specific soil conditions related to phosphoro and calcium were also detected as beneficiary tothe successional processes. Our results suggest that applying fire restriction and periodiccutting of the bracken fern, this can increase a higher diversity of species.


9.
Artículo
*Solicítelo con su bibliotecario/a
Succession and the relationship between vegetation and soil in the Marl Quarries of the Yucatan Peninsula, Mexico
Valdéz Hernández, Mirna ; Gil Medina, Rossana (coaut.) ; López Martínez, Jorge Omar (coaut.) ; Torrescano Valle, Nuria (coaut.) ; Cabanillas Terán, Nancy (coaut.) ; Islebe, Gerald A. (coaut.) ;
Contenido en: Forests Vol. 10, no. 116 (2019), p. 1-13 ISSN: 1999-4907
Nota: Solicítelo con su bibliotecario/a
PDF

10.
Artículo
*Solicítelo con su bibliotecario/a
Wetland geomorphology and paleoecology near Akab Muclil, Rio Bravo floodplain of the Belize coastal plain
Krause, Samantha ; Beach, Timothy (coaut.) ; Luzzadder Beach, Sheryl (coaut.) ; Cook, Duncan (coaut.) ; Islebe, Gerald A. (coaut.) ; Palacios Fest, Manuel R. (coaut.) ; Eshleman, Sara (coaut.) ; Doyle, Colin (coaut.) ; Guderjan, Thomas H. (coaut.) ;
Contenido en: Geomorphology Vol. 331 (April 2019), p. 146-159 ISSN: 0169-555X
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

To understand wetland geomorphology and paleoecology, we collected a 2.6 m sediment core from a flooded swamp adjacent to the Maya archaeological site of Akab Muclil in the Maya Lowlands of northwestern Belize. The site of Akab Muclil has a known occupation that persisted from Early Maya Classic (1700–1350 BP) through the Terminal Maya Classic (1180–1050 BP) and into the Postclassic (1050–450 BP) and lies near a vast networkof ancient Maya canal andfield systems. We analyzed this core using a combination of paleoecological and geochemical techniques to determine the history of land use and natural change over time within this wetland. Accelerator Mass Spectrometry dating, pollen, charcoal analysis, micropaleontology, geochemical analysis, andmagnetic susceptibility provide a suite of methods from which we interpret the geomorphic and ecological history of this wetland system. Four AMS dates from the length of the core provide us with an age model that runs from 1675 cal BP through the Maya Classic onward to the present. At the base of this system, soil composition and chemistry provide evidence that the system changed from a seasonally wet terrestrial soil to a perennially wet swamp, as the basal Mollisol soil lies buried by peats and calcareous sediments.

This shift to a perennial wetland could be related to ancient Maya water management or a natural geomorphic change, though we suspect the former because of nearby ancient Maya large-scale geomorphic and hydrological manipulation in the form of intensive canalization and agriculture. Evidence of ancient Maya uses and impacts, including sedimentation, Zea mays pollen, and high charcoal counts occur from the lowest levels of the sequence through the Classic and into the Postclassic period. Above this level, the strata change to stable peats, laminated depositsof light gray/dark gray gypsum, authigenic carbonate, and layers offibrist peat, with little evidence of human impact until recent increases in charcoal and phosphorous. This study, compared with other regional studies, indicates a later transition from terrestrial to wetland, later human impacts in the Postclassic, and a geomorphic impact record closely tied to the history of the adjacent site rather than broader land use trends.