9801297 Dillon Predictions of major climatic impacts in the Americas from developing El Nino conditions include greatly increased rainfall in deserts of northern South America. Past El Nino conditions, in 1982 and again in 1987, led to dramatic increases in the appearance of flowering plants in the very dry deserts of coastal Chile and Peru, especially in zones subject to regular fogs and known as "lomas" communities. For many years the botanist Dr. Michael Dillon of the Field Museum of Natural History and his ecologist colleague Dr. Philip Rundel, working with Chilean and Peruvian colleagues, have been studying the flora and vegetation of these hyper arid regions. They have amassed specimens and associated observational data documenting the occurrence of 1175 species of flowering plants, placed in 418 genera in 97 families, in various lomas formations in the two countries. Many of these are rare or ephemeral in occurrence, and for most little is known about seed longevity in the soil and germination requirements, or about growth and development to reproduction. Long term monitoring of basic ecological information, like vegetation cover, composition, and turnover, has been possible at just a few field sites, in collaboration with host-country colleagues. Expedited funding through this Small Grant for Exploratory Research program makes it possible to respond promptly to the opportunity for floristic and ecological monitoring of desert regions in northern Chile and southern Peru, during the impending ENSO event. Species changes will be integrated with existing databases know accessible through the Web, and authenticated by specimen collections at the Field Museum and elsewhere. Ecological monitoring will lay the basis for more sophisticated studies on drought tolerance in relation to photosynthetic pathways and water relations. Field work this coming year will make possible direct comparison with floristic and vegetational conditions documented from previous El Nino years.
