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13 resultados encontrados para: AUTOR: Hooghiemstra, Henry
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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
Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years
Marchant, R. ; Islebe, Gerald A. (coaut.) ; Hooghiemstra, Henry (coaut.) ; Markgraf, Vera (coaut.) ;
Contenido en: Climate of the Past Discussions Vol. 5 (2009), p. 369-461 ISSN: 1814-9340
Resumen en: Inglés |
Resumen en inglés

The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation

At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small; change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America show a change in biome assignment, but to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat´an peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded

At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation reflecting a generally cool and dry environment. Cool grass/shrubland is prevalent in southeast Brazil whereas Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central Mexico and lowland Colombia remain unchanged in the biome assignments of warm mixed forest and tropical dry forest respectively, although the affinities that these sites have to different biomes do change between 18 000±1000 14C yr BP and present. The “unresponsive” nature of these sites results from their location and the impact of local edaphic influence.


3.
Tesis - Doctorado
Reconstrucción paleoambiental del Holoceno medio-tardío en la parte centro-sur de la Península de Yucatán, México / Nuria Torrescano Valle
Torrescano Valle, Nuria ; Islebe, Gerald A. (tutor) ; Villanueva Gutiérrez, Rogel (asesor) ; Hooghiemstra, Henry (asesor) ; Behling, Hermann (asesor) ;
Chetumal, Quintana Roo, México : El Colegio de la Frontera Sur , 2007
Clasificación: TE/574.52220972 / T6
Cerrar
SIBE Campeche
ECO040002993 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
ECO030006594 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
ECO010010083 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
ECO020011168 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Villahermosa
ECO050003183 (Disponible)
Disponibles para prestamo: 1
Resumen en español

El presente trabajo estudia la historia de la vegetación y clima en la península de Yucatán, y representa una fuente de información para el establecimiento de escenarios futuros. Cambios experimentados durante el Holoceno Medio-Tardío fueron identificados mediante el análisis de polen fósil, extraído de columnas de sedimento de diferentes sitios de la península. Los taxa indicadores de condiciones ecológicas y las asociaciones vegetales, fueron calibrados mediante el análisis de la relación actual de la vegetación y lluvia moderna de polen. Mediante técnicas de datación radiocarbono y diversas herramientas estadísticas se realizó el establecimiento de cronologías. Los escenarios de cambio paleoambiental muestran condiciones de mayor humedad y temperatura que las actuales durante la fase tardía del Holoceno medio hasta ~4800 años antes del presente. Posteriormente el clima se deterioró paulatinamente debido a diferentes factores climáticos, como variación en la insolación causada por los ciclos solares naturales, así como cambios en la convergencia de vientos provenientes del Atlántico norte y corrientes oceánicas. Condiciones cálidas pero menos húmedas se incrementaron en los últimos 3000 años. Fuertes sequías son identificadas por disminución en elementos de selva y el incremento de elementos de vegetación secundaria. Los registros fósil cercanos al mar revelan eventos relacionados con la definición de la línea de costa, cambios en la distribución y composición de vegetación de manglar indican incrementos en el nivel del mar, así como eventos ligados al desbordamiento del río Hondo.

El establecimiento de la cultura maya se identificó mediante la presencia de maíz (Zea mays) y el incremento de otros elementos de vegetación abierta y perturbada. La interferencia en los registros producida por disturbio humano fue menor en los registros de manglar, pero la disminución de la vegetación de manglar y selva revelan fuertes sequías, y refuerzan la hipótesis que asocia al colapso maya con fuertes variaciones climáticas durante el periodo clásico (250 AD Anno Domini). Posterior al colapso maya se identifica el retorno de la selva. Los eventos identificados presentan correspondencia con otros registros de polen fósil, isótopos de oxígeno y densidad de sedimentos, realizados en estudios previos. Mediante el presente trabajo fue posible identificar cambios ambientales producidos por variaciones climáticas, además de los cambios producidos por influencia humana.

Resumen en inglés

This thesis deals with the vegetation and climate history of the Yucatán peninsula and represents a source for information for posible future climate change scenarios. Environmental changes from the mid to late Holocene were identified by pollen analisis. Sediment cores were taken at different lakes of the Yucatán peninsula. Indicador taxa of dominant ecological conditions were elucidated and the relationship of actual vegetation to present day pollen rain was established. By means of radiocarbon dating and statistical analisis a chronology is proposed. Paleoecological data show conditions of higher precipitation and temperature in the mid Holocene, 4800 BP. Later climate changed due to different factors, like changes in radiation by natural cycles, and changes in ocean currents. Warm climate but less humid established in the last 3000 years. Drought was detected and is reflected in changes in forest elements and increase of species from secondary habitats. The pollen record from the sites near coastal areas show establishment of present coast line vegetation, as changes in the distribution and floristic composition of mangroves show increase of sea level and flooding in the Rio Hondo area. Presence of Maya culture is indicated by appearance of Zea mays and other elements of open and disturbed vegetation. Human impact in mangrove areas is less obvious, but the decrease of characteristic elements in cover in mangrove and forest areas, support the idea of strong environmental changes since the Classic period (250 AD onwards), impact on natural vegetation is further supported by agricultural evidence.

After the Maya collapse the forest recovered. Climate changes recorded by pollen evidence agree with changes registered by other proxy like oxygen isotopes and sediment density from other studies. This thesis shows environmental change by climatic variations, as well as changes due to human impact.

Índice

Capítulo I Introducción y Objetivo
Capítulo II Área de estudio y Método
Capítulo III Relación lluvia de polen-vegetación en la península de Yucatán basada en trampas naturales y artificiales. Yucatan Peninsula pollen rain-vegetation relationship as derived from natural and artificial pollen traps
Capítulo IV Historia de la selva tropical y manglar desde el sureste de Mexico: 5000 años de registro de polen e implicaciones en el nivel del mar. Tropical forest and mangrove history from southeastern Mexico: a 5000 yr pollen record and implications for sea level rise
Capítulo V Cronología del Holoceno tardío
Capítulo VI Discusión y Conclusiones
Anexo Normas editoriales


4.
Tesis - Doctorado
Cambios paleovegetacionales durante el holoceno en la Selva Lacandona, Chiapas / Gabriela Domínguez Vázquez
Domínguez Vázquez, Gabriela ; Islebe, Gerald A. (tutor) ; Villanueva Gutiérrez, Rogel (asesor) ; Monks Sheets, Scott William (asesor) ; Hooghiemstra, Henry (asesor) ;
Chetumal, Quintana Roo, México : El Colegio de la Frontera Sur , 2004
Clasificación: TE/560.45 / D6
Cerrar
SIBE Campeche
ECO040001671 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
ECO030000752 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
ECO010005101 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
ECO020006001 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Villahermosa
ECO050001922 (Disponible)
Disponibles para prestamo: 1
Índice

Introducción
Objetivos e hipótesis
Método
Capítulo 1. Relictos pleistocénicos en la vegetación de la selva Lacandona
Capítulo 2. Modern pollen deposition in Lacandon forest, Chiapas, México
Capítulo 3. Evidence of a long lasting drought during the late Holocene in the Lacandon rain forest, Mexico
Discusión y conclusión
Literatura citada
Anexos


5.
- Capítulo de libro con arbitraje
The rise and fall of peruvian and Central American civilizations: interconnections with the Holocene climatic change - a necessarily complex model
Marchant, Robert A. (autor) ; Hooghiemstra, Henry (autor) ; Islebe, Gerald A. (autor) ;
Clasificación: AR/574.522209728 / M3
Contenido en: Monsoon and civilization / edited by Yoshinori Yasuda, Vasant Shinde Kyoto, Japan : International Research Center for Japanese Studies, 2004 p. 351-376 ISBN:817-4363-05-X
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
ECO010018358 (Disponible)
Disponibles para prestamo: 1

6.
Artículo
*En hemeroteca, SIBE-Chetumal
Climatic change during the Younger Dryas chron in northern South America: a test of the evidence
Veer, Ron van 'T ; Islebe, Gerald A. (coaut.) ; Hooghiemstra, Henry (coaut.) ;
Contenido en: Quaternary Science Reviews Vol. 19, no. 17-18 (December 2000), p. 1821-1835 ISSN: 0277-3791
Nota: En hemeroteca, SIBE-Chetumal
Resumen en: Inglés |
Resumen en inglés

New AMS and palynological data are presented from the Colombian Andes to assess vegetational and climatic change during the Lateglacial–Holocene transition, with special emphasis on the Younger Dryas (YD) chronozone. The new evidence is compared and discussed with other Colombian cores and with data from other countries in the region. The Lateglacial climatic reversal in Colombia, known as the El Abra stadial, has an estimated lower boundary of 11,200 (conventional) and 10,900 (interpolated) 14C yr BP, respectively. Although the El Abra stadial is assumed to be the equivalent of the European YD, the present data suggest that the El Abra stadial is a biostratigraphical signal representing both the YD chronozone and the earliest Holocene (11,000–9000 14C yr BP). On the basis of new AMS dates and a re-evaluation of the pollen zones, we divided the Colombian El Abra biozone into two phases. From ca. 11,000 to ca. 10,500 14C yr BP there is a sharp increase of subparamo and paramo pollen, reflecting a relatively cool phase during the YD chronozone (zone Y1). After ca. 10,500 14C yr BP, a slight increase of arboreal pollen and the presence of Cactaceae (zone Z1) point toward a relatively milder but drier phase extending to ca. 9000 14C yr BP in the earliest Holocene.

Our conclusions add detail to the concept of astronomical forcing of contrasting rainfall changes in northern South America between 12,400 and 8800 14C yr BP. We propose an environmental drought during the El Abra biozone, with subsequent erosion of the sediments deposited during that period, as a major factor explaining the poor presence of YD evidence in northern South America. We conclude that at hydrologically sensitive sites without a clear lithological change around 11,000–9000 14C yr BP, a hiatus during the YD chronozone can only be detected if other cores are available with bracketed time control. We state that the start of the temperature decline in Central America and northern South America is related to the global YD cooling event. However, much work is still required to understand the duration and amplitude of the climatic reversal during the YD chronozone in this part of the globe.


7.
Artículo
*En proceso técnico. Solicítelo con el bibliotecario de SIBE-Chetumal
A multi-proxy study of Holocene environmental change in the Maya Lowlands of Peten, Guatemala
Curtis, Jason H. (autor) ; Brenner, Mark (autor) ; Hodell, David A. (autor) ; Balser, Richard A. (autor) ; Islebe, Gerald A. (autor) ; Hooghiemstra, Henry (autor) ;
Contenido en: Journal of Paleolimnology Vol. 19, no. 2 (1998), p. 139-159 ISSN: 0921-2728
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
44481-10 (Disponible)
Disponibles para prestamo: 1
Nota: En proceso técnico. Solicítelo con el bibliotecario de SIBE-Chetumal

8.
Capítulo de libro
*En proceso técnico. Solicítelo con el bibliotecario(a) de SIBE-San Cristóbal
Registro palinológico de los últimos 10000 años en la Laguna Quila, México
Almeida Leñero, Lucía (autor) ; Hooghiemstra, Henry (autor) ; Cleef, Antoine M. (autor) ; Islebe, Gerald A. (autor) ;
Contenido en: Vegetación, fitogeografía y paleoecología del zacatonal alpino y bosques montanos de la región central de México p. 221-237
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
54233-10 (Disponible)
Disponibles para prestamo: 1
Nota: En proceso técnico. Solicítelo con el bibliotecario(a) de SIBE-San Cristóbal

9.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
Vegetation and climate history of montane Costa Rica since the last glacial
Islebe, Gerald A. ; Hooghiemstra, Henry (coaut.) ;
Contenido en: Quaternary science reviews Vol. 16, no. 6 (1997), p. 589-604 ISSN: 0277-3791
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

New palynological evidence from the Cordillera de Talamanca (Costa Rica) is presented. The La Chonta-1 core (2310 m a.s.l) shows the development of montane vegetation during the late Quaternary. A shorter core (La Trinidad-III) shows the Lateglacial-Holocene transition, including the La Chonta stadial based on earlier published evidence. A soil section from the paramó belt at 3100 m shows vegetation recovery after fire. Modern pollen rain was studied along an altitudinal transect from 2100 m to 3800 m at Mt Chirripó. A comparison with other palaeoecological data of the region is given to elucidate climatic and vegetational changes throughout the Central American region. Data show a cooling of 7–8°C during the Last Glacial Maximum (LGM) for montane Costa Rica, which is in accordance with data from lowland Guatemala. A 1.5° to 2.5°C temperature drop is recorded during the Younger Dryas Chron in both Costa Rica and Guatemala, but apparently not in Panama. The Lateglacial-Holocene transition in montane Costa Rica is established at 10,400 BP. Between 9000 and 8500 BP moist forest developed in mountainous Costa Rica as well as in lowland Guatemala and Panama. Environmental change during the mid-Holocene seems more affected by changes in humidity than temperature change throughout Central America. Distribution maps of paramó and montane vegetation in Costa Rica are reconstructed for 10 ka, 14 ka and 18 ka based on currently available palynological data. These data indicate that during the LGM a paramó vegetation corridor existed between northern Costa Rica and probably northern Panama.


10.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
Holocene vegetation and water level history in two bogs of the Cordillera de Talamanca, Costa Rica
Islebe, Gerald A. ; Hooghiemstra, Henry (coaut.) ; Veer, Ron van 't (coaut.) ;
Contenido en: Vegetatio Vol. 124, no. 2 (Jun. 1996), p. 155-171 ISSN: 1948-1996
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

Pollen records of Holocene sediment cores from the Costa Rican Cordillera de Talamanca (La Chonta bog, 2310 m and La Trinidad bog, 2700 m) show the postglacial development of the montane oak forest zone from ca. 9500 to 1500 yr BP. During the early Holocene (ca. 9500-7000 yr BP), alder vegetation covered the La Chonta and La Trinidad bogs and their adjacent hills. The upper forest line is inferred to be at 2800-3000 m elevation. A Podocarpus-Quercus forest characterised the middle Holocene (ca. 70(0)°4500 yr BP). The upper forest line is located at >3000 m reaching the present-day altitudinal distribution. A Quercus forest characterised the late Holocene (ca. 4500-1500 yr BP). Compared to modern conditions, the early Holocene has similar average temperatures, but the moisture level was probably higher. Pollen evidence for the late Holocene indicates drier environmental conditions than today. In order to improve the paleoecological interpretation, we described the local vegetation and used moss samples as pollen traps at both montane bogs along strong soil moisture gradients.