English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

10p. Fotog. Color, Diagramas y gráficas.[EN] This paper reports the preliminary palynological results, at a millennial scale, of a Holocene peat bog sequence,\udsince around 8.0 cal kyr BP to the present, obtained in the summit of the Apakará-tepui (2170 m elevation), in the\udChimantá massif, located in the neotropical Venezuelan Guayana. The early Holocene was characterized by a vegetation\uddifferent to the present, in which trees and shrubs dominated and Myrica (Myricaceae) was the main element\udof the gallery forests around a permanent water body, as indicated by the continuous presence of Isoëtes (Isoëtaceae)\udin high percentages. Around the middle Holocene (5.3 cal kyr BP), a shift towards more herbaceous and non-flooded\udcommunities occurred, and the present day vegetation established. This has been interpreted as a shift from warmer\udand wetter climates to cooler and drier conditions. The first phase, from 8.0 to 5.3 cal kyr BP, falls within a warming\udphase widely documented worldwide, known as the Holocene Thermal Maximum. The millennial trends shown here\udwill be refined with further studies at centennial to decadal time scales. These results support the hypothesis that\udthe best sites to detect paleoenvironmental changes in the summits of the tabular Guayana mountains are close to\udaltitudinal ecotones.[ES] Este artículo presenta los resultados palinológicos preliminares, a escala de milenios, de una secuencia holocena,\uddesde 8.0 cal kyr BP hasta la actualidad, obtenida en la cima del Apakará-tepui (2170 m de altitud), en el Macizo del\udChimantá, situado en la región neotropical de la Guayana venezolana. El Holoceno temprano se caracterizó por una\udvegetación diferente a la actual, dominada por árboles y arbustos, en la que Myrica L. (Myricaceae) era el elemento\udprincipal de los bosques de ribera que circundaban un cuerpo de agua permanente, como indica la presencia contínua\udde Isoëtes L. (Isoëtaceae). Durante el Holoceno medio (5.3 cal kyr BP), se produjo un cambio a una vegetación más\udherbácea, estableciéndose las comunidades que actualmente ocupan el área. Ésto se interpreta como indicativo de un\udcambio desde climas más cálidos y húmedos a condiciones más frías y secas. La primera fase, de 8.0 a 5.3 cal kyr BP,\udcoincide con una fase climática cálida ampliamente documentada a nivel global, conocida como el Máximo Térmico\uddel Holoceno. Las tendencias milenarias obtenidas en este trabajo se refinarán con futuros estudios a escala de siglos\udy décadas. Estos resultados apoyan la hipótesis de que las mejores localidades para estudiosThis research was supported by projects BIOCON 2004 90/05 (BBVA Foundation, Spain), CGL2006-00974/BOS and CGL2009-07069/BOS (by the Ministry of Science and Innovation\udof Spain). Official permits to develop this research in\udVenezuela and sampling permits were provided by the Ministry\udof Science and Technology of Venezuela (n°. 13, 5 Jan 2007) and the Ministry of Environment of the same country\ud(n°. IE-085, 9 Feb 2007), respectively.Peer reviewe

Preliminary palynological analysis of a Holocene peat bog from Apakará-tepui (Chimantá Massif, Venezuelan Guayana)