The vegetation of western South America is influenced by periodic and recurrent El Niño events. The physics behind the El Niño or El Niņo Southern Oscillation (ENSO) phenomenon is complex and readers are urged to consult numerous sites that provide a more complete explanation of the origins and monitoring of ENSO events [El Niņo Web Links]. Simply put, El Niño conditions prevail when the normally cold waters of the coast of western South America are displaced by a warmer, western Pacific surface and subsurface body of water that stimulates brief periods of heavy rainfall and relatively high temperatures. This influx of available moisture has profound effects within the lomas formations and has undoubtedly helped shape their composition and structure. This portion of the site is under active construction and will be expanding in the coming months.
Research has been supported, in part, by National Science Foundation grants: Biogeography and Evolution of the Lomas formations of Peru and Chile (BSR-8513205) and Botanical Collections and Ecological Observations in Coastal South American Deserts during the 1997/98 ENSO Event (DEB-801297). Support from the National Geographic Society is also acknowledged.