Growth and functional trait responses of Berberis lutea to Super El Niño events in Peruvian altimontane shrublands

Guerra A.; Rodríguez-Ramírez E.C. · Dendrobiology (2026) · DOI: 10.12657/denbio.095.012

Resumen

Shrubs are key components of high‑Andean xeric ecosystems and provide valuable dendroclimat‑ ic information where tree records are scarce, yet their responses to extreme El Niño‑Southern Oscillation (ENSO) anomalies remain poorly understood. We developed the first shrub‑ring chronologies of Berberis lutea from two Peruvian altimontane shrublands (San Pedro de Saños and Singua Chico) to evaluate cli‑ mate‑growth relationships and the effects of Super El Niño events on radial growth sensitivity, resilience, and wood anatomical traits. Ring‑width chronologies were analysed against temperature, precipitation, evapotranspiration, and Niño 3.4 sea surface temperature anomalies. Resistance, recovery, and resilience indices, together with wood anatomical traits and fourth‑corner analyses, were used to assess functional responses during the 1997/98 and 2015/16 Super El Niño events. B. lutea formed clear annual rings with strong common signals and high inter‑series coherence, confirming its suitability for dendroclimatic stud‑ ies. Radial growth was mainly driven by temperature, evapotranspiration, and ENSO‑related sea surface temperature variability, whereas precipitation showed weaker and site‑dependent effects. Notably, a neg‑ ative precipitation‑growth correlation was found at the lower‑elevation site (San Pedro de Saños), which we attribute to cloud‑cover limitation and transient soil waterlogging – mechanisms that are now explicitly discussed. Super El Niño events caused moderate reductions in radial growth followed by rapid, site‑spe‑ cific recovery, with greater resilience at San Pedro de Saños. These growth responses were accompanied by narrower vessel diameter and reduced vessel length, indicating conservative hydraulic adjustments under extreme climatic stress. Overall, B. lutea emerges as a reliable climate proxy and a strong bioindicator of resilience to increasing ENSO‑driven climate extremes in high‑Andean semi‑xeric ecosystems.

Instituciones: Universidad Tecnológica del Perú