ENSO Signals Recorded by Ash Tree Rings in Iberian Riparian Forests

Climate–atmospheric patterns affect ecological processes. The El Niño Southern Oscillation (ENSO) represents the strongest global source of climate variability at annual scales, but its impacts on Mediterranean forests are still understudied. Here, ENSO signals recorded by river flow and radial growth series riparian uncovered in middle Ebro basin, northeastern Spain. A chronology or mean tree ring widths (period 1970–2018, 27 trees) was built for narrow-leaved ash (Fraxinus angustifolia). Growth indices increased as did during prior winter from May to September. Ash hydrological year were positively related (r = 0.54, p < 0.001), suggesting that a higher soil moisture enhances growth. This correlation remained significant after taking out influence precipitation. −0.46, 0.001) −0.30, 0.03) negatively associated with January Index (SOI). These relationships suggest high SOI values corresponding La Niña events lead reduced flow, thus decreasing Further approaches could be used better understand how drought-prone subjected increasing aridity.