Dendroclimatic potential of the Adesmia pinifolia shrub growing at high altitude in the Andes foothills

Abstract

Highland ecosystems of western Andes foothills are currently poorly represented by dendrochronological information. The dendroclimatological potential of the Acerillo plant (Adesmia pinifolia), a shrub species well represented at these latitudes, was investigated. We reported the first ring width chronology of A. pinifolia growing at the central semi-arid Andes foothills of Argentina. We collected living and dead wood samples of Acerillo resulting in a chronology covering the period 1609–2020 (412 years) with a well replication from 1655 to present (> 13 samples). Bootstrapping correlation analysis revealed a strong positive relationship between our chronology and monthly precipitation and with the Standardized Precipitation Evapotranspiration Index (SPEI-12 months). For the last 40 years however, strong negative correlations with temperature are evidenced. The dendrochronological record also showed a negative relationship with sea surface temperatures from the Tropical Pacific, suggesting teleconnections with the El Niño Southern Oscillation (ENSO) phenomenon. The strong hydroclimatic signal recorded in the A. pinifolia chronology represents a high opportunity to produce long-term proxy climate data for the Central Andes foothills, an extensive region devoid of trees but of hydrological relevance for the support of important economic activities.