The streamflow variability of the Acaponeta River inferred from tree-ring series of conifers

From a dendrochronological network composed by eight conifer species, a regional chronology (CR-Acaponeta) for the upper watershed of the Acaponeta River was built, to reconstruct the variation of the streamflow (MS) from 1700 to 2013 (314 y). The dating quality was verified with Cofecha showing intercorrelations from 0.47 to 072, indicating a common signal for tree growth. The correlation between individual chronologies and the CR-Acaponeta varied from 0.32 to 0.87, and the sample required to reach an expressed population signal (EPS) of 0.85 was from 7 to 17 trees. The residual chronologies correlated to MS were that for total ring (RWIr) and late wood (LWr). The transformation of MS into Log10 and square root values and the use of the VERIFY subroutine from "Dendrochronology Program Library" led to equations for reconstructing MS of January-August (r = 0.74, p < 0.01) and August-October (r = 0.69, p < 0.01) from RWIr and LWIr, respectively. The capability of the equations to predict in ranges out of the observed data was significant with reduction errors of 0.479 and 0.465, respectively. The variation of MS January-August was negatively correlated to ENSO (r = -0.632, p < 0.01, 1876-1996), with an inverse and significant relationship between the RWIr and South Oscilaltion of winter. This correlation increased to -0.76 (p < 0.01) when considering only the most intense ENSO events. This work shows the potential of streamflow reconstruction from tree ring nets in west Mexico, providing useful information for the planning and management of the hydrological resources.