DENDROCRONOLOGÍA DE Pinus cembroides Zucc. Y RECONSTRUCCIÓN DE PRECIPITACIÓN ESTACIONAL PARA EL SURESTE DE COAHUILA

Abstract

Ring width indices of pinyon pine were used to develop a seasonal Winter - Spring (January - June) precipitation reconstruction on the last 410 years (1595 – 2004) for southeastern Coahuila. The objectives of this study were to analyze the dendrochronological potential of Pinus cembroides, to develop a seasonal precipitation reconstruction, to determine hydroclimatic fluctuations in time, and to analyze the influence of atmospheric circulatory patterns like El Niño. Some statistical parameters of the chronology such as series intercorrelation with a value of 0.72, climate sensitivity with 0.31, signal - to - noise ratio of 22.94, standard deviation of 0.30, and first order autocorrelation of 0.26 had values considered excellent for dendroclimatic reconstruction purposes. The ring - width chronology explained 52% of the seasonal precipitation variance. The reconstructed drought periods supported by historical archives and tree - ring reconstructions for this and northern Mexico regions were: 1784 to 1794, 1850 to 1857, 1860 to 1884, and 1945 to 1962. Droughts were detected at frequencies of 50 to 60 years. Wet episodes were present in the reconstruction at the periods of 1620 to 1639, 1647 to 1661, 1672 to 1685, 1766 to 1780, 1900 to 1916, and 1966 to 1994. The seasonal precipitation reconstructions did not show a significant association with the warm phase of El Niño phase but was significantly correlated with the All Mexico Precipitation Index.