The Extravagant Physical Geography of Chile

Abstract

Current Chilean vascular flora and its biogeographical patterns are strongly related to the geographical features of the territory, past and present. Main characteristics of the physical geography of Chile are described, with emphasis on the geologic and climatic changes that affected the biome configuration since the Devonian onwards. Approaching the present time, the effects of the Pleistocene glaciations in the distribution of several communities are discussed. Chile has been characterized as ``a geographic extravaganza{''} (Subercaseaux 1940) due to its impressive geographical contrasts: it contains the driest desert on the planet, formidable inland ice fields, active volcanoes, fjords, geysers, a vast coastline and the major highs of the Andes. The country stretches for 4,337 km along the south-western margin of South America from the Altiplano highs at 17 degrees 35'S to Tierra del Fuego, the Islas Diego Ramirez and Cape Horn at 56 degrees S (Figs. 1.1 and 1.2). Chile's boundary to the west is the wide Pacific Ocean. The national territory includes several groups of Pacific oceanic islands, principally Rapa Nui (Easter Island), the Juan Fernandez archipelago, and the Desventuradas Islands (Fig. 1.1) (Chap. 5). Besides this the nation has a geopolitical claim on a portion of 1,250,000 km(2) in Antarctica. Though geopolitical interests are beyond the scope of this book, and despite the modest presence of extant vascular plants in Antarctica (only Deschampsia antartica and Colobanthus quitensis), the Continent of Ice is of high interest regarding the origin of the Chilean plant world (Sect. 1.2, Box 9.1).