Precipitation sensitivity of high-altitude Polylepis pepei in Northern Bolivia

ROSE OELKERS; LAIA ANDREU-HAYLES; ERNESTO TEJEDOR VARGAS; ARTURO PACHECO-SOLANA; CLARA RODRIGUEZ MORATA; M. EUGENIA FERRERO

New Orleans, LA & Online

Conferencia; American Geophysical Union -AGU- Fall Meeting; 2021

American Geophysical Union

Understanding the full range of precipitation variability in the tropical Andes in South America is challenging due to a lack of long-term station records. In addition, large elevation gradients and heterogenic topography adds to the complexity of how, when, and where rainwater falls. Developing tree-ring records can inform about past climate variability. In this study, we analyzed a recently developed Polylepis pepei tree-ring width network in northern Bolivia in the Madidi National Park, which include trees located between 3,700 and 4,200 m a.s.l. Additionally, we used a new high-resolution gridded daily precipitation database for the 1960-2015 period, which improves the precipitation signal detected in the tree-ring records. Our results show that the ring-width reflects a significantly positive relationship to austral summer (Jan-Feb) precipitation variability in recent decades. Therefore, these high altitude-low latitude trees have the potential to provide insights of the intra-annual and decadal precipitation variability for the past 150 years. Disentangling the ring-width response of trees growing in high-elevation forests in the neotropics, like those in Bolivia, is key to advance in the effort to produce regional and historical climate information in the tropical Andes.