Science 12 November 2010:
Vol. 330. no. 6006, pp. 957 - 961
DOI: 10.1126/science.1193833
Effects of Rapid Global Warming at the Paleocene-Eocene Boundary on Neotropical Vegetation
Carlos Jaramillo,1,* Diana Ochoa,1,2 Lineth Contreras,3,1,4 Mark Pagani,5 Humberto Carvajal-Ortiz,6,1Lisa M. Pratt,6 Srinath Krishnan,5 Agustin Cardona,1 Millerlandy Romero,1 Luis Quiroz,1,7Guillermo Rodriguez,3,8 Milton J. Rueda,9,3 Felipe de la Parra,3 Sara Morón,1,10 Walton Green,1German Bayona,11,1 Camilo Montes,1,11 Oscar Quintero,12 Rafael Ramirez,13 Germán Mora,14Stefan Schouten,15 Hermann Bermudez,16 Rosa Navarrete,17 Francisco Parra,18 Mauricio Alvarán,16Jose Osorno,19 James L. Crowley,20 Victor Valencia,21 Jeff Vervoort22
Temperatures in tropical regions are estimated to have increased by 3° to 5°C, compared with Late Paleocene values, during the Paleocene-Eocene Thermal Maximum (PETM, 56.3 million years ago) event. We investigated the tropical forest response to this rapid warming by evaluating the palynological record of three stratigraphic sections in eastern Colombia and western Venezuela. We observed a rapid and distinct increase in plant diversity and origination rates, with a set of new taxa, mostly angiosperms, added to the existing stock of low-diversity Paleocene flora. There is no evidence for enhanced aridity in the northern Neotropics. The tropical rainforest was able to persist under elevated temperatures and high levels of atmospheric carbon dioxide, in contrast to speculations that tropical ecosystems were severely compromised by heat stress.
1 Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Ancon Republic of Panama.
2 Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614–14850, USA.
3 Colombian Petroleum Institute, Km 7 Via Piedecuesta, Bucaramanga, Colombia.
4 Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, D-60438 Frankfurt am Main, Germany.
5 Department of Geology and Geophysics, Yale University, New Haven, CT 06520, USA.
6 Department of Geological Sciences, Indiana University, Bloomington, IN 47405, USA.
7 Department of Geology, University of Saskatchewan, 114 Science Place, Saskatoon SK, Canada.
8 Department of Geological Sciences and Engineering, Missouri University of Science and Technology, Rolla, MO 65409–0140, USA.
9 Paleoflora Limitada, Calle 9 No. 9-09, Zapatoca, Colombia.
10 Department of Geology, University of Minnesota, Minneapolis, MN 55455–0231, USA.
11 Corporación Geológica Ares, Calle 57 N.24-11 ofic. 202, Bogotá, Colombia.
12 Petróleos de Venezuela S.A. (PDVSA) Exploración, Nucleoteca La Concepción, Maracaibo, Venezuela.
13 PDVSA Exploración, Edificio Guaraguao Puerto de la Cruz, Venezuela.
14 Goucher College, 1021 Dulaney Valley Road, Baltimore, MD 21204, USA.
15 Royal Netherlands Institute for Sea Research (NIOZ), Department of Marine Organic Biogeochemistry, Post Office Box 59, 1790 AB, Den Burg, Texel, Netherlands.
16 Department of Geological Sciences, University of Caldas, Manizales, Colombia.
17 Paleosedes, Tv 27 No. 57-49 Bogota, Colombia.
18 Université Paul Sabatier, CU Ponsan Bellevue, Rue Maurice Becanne, 31078 Tolulouse CX 04, France.
19 Agencia Nacional de Hidrocarburos, Bogotá, Colombia.
20 Department of Geosciences, Boise State University, Boise, ID 83725–1535, USA.
21 Valencia Geoservices, Tucson, AZ 85712, USA.
22 School of Earth and Environmental Sciences, Washington State University, Pullman, WA 99164–2812, USA.
* To whom correspondence should be addressed. E-mail: jaramilloc@si.edu
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NOTA CAUSTICANTE [Eu não pude resistir...] DESTE BLOGGER:
Eu queria ver a cara do Al 'Zé do Apocalipse' Gore ao tomar conhecimento desta descoberta científica: a pesquisa contraria muito o anúncio de iminente destruição das espécies e do planeta.
Não discuto que o clima está mudando, mas sou cético localizado de que seja UNICAMENTE provocado por ações humanas. O buraco do ozônio é mais embaixo, diria o Macaco Simão.
Fui, nem sei por que, pensando: o que teria provocado a Idade do Gelo??? Ações antropogênicas ou simples fenômeno natural???
