Archivo:H Hooghiemstra & SGA Flantua 2019 Colombia Quaternary-environmental & climatic change.pdf
H_Hooghiemstra_&_SGA_Flantua_2019_Colombia_Quaternary-environmental_&_climatic_change.pdf (tamaño de archivo: 3,54 MB; tipo MIME: application/pdf)
Hooghiemstra, H. & Flantua, S.G.A. 2019. Colombia in the Quaternary: An overview of environmental and climatic change. In: Gómez, J. & Pinilla–Pachon, A.O. (editors), The Geology of Colombia, Volume 4 Quaternary. Servicio Geológico Colombiano, Publicaciones Geológicas Especiales 38, 52 p. Bogotá. https://doi.org/10.32685/pub.esp.38.2019.02
We provide an overview of environmental and climatic change in Colombia during the Quaternary, the last ca. 2.58 million years (Ma) before present. This period is characterised by a suite of glacial–interglacial cycles which are remarkably well documented in Colombian sediments. The distribution of Colombia’s main ecosystems has changed repeatedly driven by orbital forcing at 21, 41, and 100 ky frequencies which were superimposed by millennial–scale (ca. 2.5 ky) climate oscillations. Fossil pollen records have detected biome dynamics through time but records vary in length: the shortest comes from the Chocó rainforest (extending back to ca. 7 thousand years before present, ka) and dry inter–Andean forest (ca. 12 ka), followed by the savannas of the Llanos Orientales (ca. 20 ka), the Amazonian rainforests (ca. 40 ka), and lower montane forest (ca. 40 ka). The longest records are from the deep sedimentary basins Bogotá (Funza09, last 2.25 Ma) and Fúquene (last 284 ka), alternatingly located in the upper montane forest and páramo during interglacial and glacial conditions, respectively. Climate change caused shifting biome distributions: mainly latitudinally in the lowlands and elevationally in the mountains. Extrinsic drivers (e.g., mean annual precipitation, length of dry season, atmospheric pCO2 , mean annual temperature, freezing days) of migration and changes in vegetation composition and intrinsic drivers (such as interspecies competition and legacy effects) are still insufficiently understood, and thus hamper meaningful projections of the effect of future environmental change on biomes. Multi–site Pleistocene and Holocene information has been spatially synthesised by developing the Latin American Pollen Database. Multi–site information has been analysed by the biomisation method to serve palaeodata–model comparisons and projections about the future of biomes in Colombia. A new method in which pollen–based palaeo–reconstructions are spatially analysed with digital elevation models improved our understanding of spatial and elevational shifts of ecotones, for example the upper forest line, in the northern Andes. In the supplementary information we highlight the strengths and weaknesses in current Quaternary palaeoecological research and provide suggestions for future research. Keywords: climate change, Colombia, environmental change, pollen records, quantitative analyses, Quaternary non–analogue environments.
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|actual||08:38 30 jun 2020||(3,54 MB)||Lcgarcia||Hooghiemstra, H. & Flantua, S.G.A. 2019. Colombia in the Quaternary: An overview of environmental and climatic change. In: Gómez, J. & Pinilla–Pachon, A.O. (editors), The Geology of Colombia, Volume 4 Quaternary. Servicio Geológico Colombiano, Publicaciones Geológicas Especiales 38, 52 p. Bogotá. https://doi.org/10.32685/pub.esp.38.2019.02 Abstract / We provide an overview of environmental and climatic change in Colombia during the Quaternary, the last ca. 2.58 million years (Ma) before present…|