This proposal concerns an initial attempt to establish a relationship between climatic variations due to El Nino and growth patterns of one or more long-lived trees found in the desert along the north Peruvian coast. Preliminary results, already in hand, indicate that some trees in this region-specifically the Sapote (Capparis Angulata R. & P.)-live for at least a few hundred years, and perhaps much longer. Although the task of determining a chronology of tree growth in the tropical desert is formidable, it appears that at least a crude chronology is possible by comparing the average growth pattern obtained from a series of transverse sections and cores from separate Sapotes with radiocarbon dating of selected Sapote samples. A concomitant study to establish ongoing growth patterns and their relationship to local climate variations will augment our current understanding of Sapote, and will add considerable insight into our research efforts. The establishment of a proxy chronology of El Nino variability over the past few centuries, particularly in the El Nino sensitive region along the north Peruvian coast, is of considerable value in our search to understand this enigmatic but economically critical phenomenon.
