Biogeografía de los bosques subtropical-templados del sur de sudamérica. Hipótesis históricas

Abstract

This work emphasizes the heuristic role of some pioneering hypotheses for understanding the complex biogeographic and evolutionary history of southern South American forests. First, I document the mixed structure of subtropical and temperate rain forests of Chile, considering the geographic distribution and phylogenetic relationships of the main components of the flora. Based on this evidence, I acknowledge the archaic character of the flora, with many lineages dating back to the Cretaceous- Paleogene, a period marked by profound geological, oceanographic, and climatic changes, coeval with the breakup of the supercontinent of Gondwana. In second place, I review the effects of fragmentation and isolation of extra-tropical forests within South America, which is related primarily to the development of the Arid Diagonal (AD) and the maximum Andean uplift during the Neogene. Finally, I review the changes in the position and intensity of the AD through the glacial-interglacial cycles of the Quaternary period, using geologic, paleoclimatic, palynologic and phylogeographic evidence.