Chihuahua southwestern hydroclimatic variability inferred with coniferous growth rings

Abstract

Introduction: The forest management unit 0807 (UMAFOR 0807) is one of the most productive in timber and water resources provision, but there are no studies of historical hydroclimatic variability and its trends for predictive purposes. Objective: To generate a precipitation reconstruction through a regional dendrochronological network for the southwest of the state of Chihuahua. Materials and methods: A network of growth series of five distinctive conifers of UMAFOR 0807 was developed; through Principal Component Analysis the series with the greatest common variance were defined to obtain a representative chronology. The reconstruction model was generated with a series of regional precipitation. The general circulation modes with the greatest impact on rainfall variability and the association of the total ring-width index with the drought indices were analyzed. Results and discussion: From eight chronologies generated, six showed a common climate response to integrate a regional representative series, which responded to September-July precipitation. The correlation between the total ring-width index and the Palmer Drought Severity Index (PDSI) was 0.68 (P < 0.01) in the June-August period, and 0.71 (P < 0.01) for the Standardized Precipitation Evapotranspiration Index (SPEI) for August of the previous year to June of the current year of growth. The reconstructed precipitation showed significance in spectral peaks of 2.1 and 2.8 years, corresponding to the influence of ENSO (El Niño-Southern Oscillation). Conclusions: The dendrochronological network composed of various tree species and integrated in a regional chronology allowed to capture the interannual and multiannual variability of the climate.