A precipitation reconstruction based on pinyon pine tree rings from the northeastern Mexican subtropic

The pinyon pines, Pinus cembroides and P. nelsonii , offer a unique example of the dendroclimatic potential of semiarid species for reconstructing cyclic low-frequency fluctuations of droughts and pluvials in northeastern semiarid Mexico. This study presents a new ring-width chronology of pinyon pines from Miquihuana, Tamaulipas, in northeastern Mexico, and uses climatic data and comparisons with the El Niño-Southern Oscillation (ENSO) and drought indices to reconstruct a historical precipitation that allows for the examination of the long-term hydroclimatic variability of seasonal rainfall, frequency of droughts and pluvials in this region, and their socio-economic impact. The radial growth of these two pinyon pines was sensitive to precipitation from November of the previous year to July of the current year. During droughts, these pinyon pines showed reduced ring-widths, but in wet years ring-widths were larger. The reconstructed precipitation extends from 1853 to 2018 (166 years) and shows high interannual and multiannual variability of precipitation influenced by ENSO, causing extreme hydroclimatic events each 2 to 4 years. The highly significant association with drought indices reinforces the potential use of pinyon pines as a proxy for determining dominant drought conditions in the region. Evidence from historical documents and dendroclimatic reconstructions from northern and central Mexico validated the main periods of drought and pluvials detected in this reconstruction. Droughts in the tree-ring record coincided with famines, migration of rural population, and warfare. Our results show a wide spectrum of natural variability in precipitation for northeastern Mexico, thus providing insights that could contribute to a better planning for regional water resources.