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| Titel |
Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years ago |
| VerfasserIn |
R. Marchant, A. Cleef, S. P. Harrison, H. Hooghiemstra, V. Markgraf, J. Boxel, T. Ager, L. Almeida, R. Anderson, C. Baied, H. Behling, J. C. Berrio, R. Burbridge, S. Björck, R. Byrne, M. Bush, J. Duivenvoorden, J. Flenley, P. Oliveira, B. Geel, K. Graf, W. D. Gosling, S. Harbele, T. Hammen, B. Hansen, S. Horn, P. Kuhry, M.-P. Ledru, F. Mayle, B. Leyden, S. Lozano-García, A. M. Melief, P. Moreno, N. T. Moar, A. Prieto, G. Reenen, M. Salgado-Labouriau, F. Schäbitz, E. J. Schreve-Brinkman, M. Wille |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 5, no. 4 ; Nr. 5, no. 4 (2009-12-01), S.725-767 |
| Datensatznummer |
250002703
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| Publikation (Nr.) |
 copernicus.org/cp-5-725-2009.pdf |
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| Zusammenfassung |
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 Yucatán 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. |
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