Influence of volcanic ash deposits on the radial growth of trees in Central Mexico: the case of Parícutin volcano

The impact of volcanic eruptions on humans and infrastructure has been significant and widely documented. However, the impact on forests covered by ash or tephra has not been as widely known or documented. This research evaluated the ashfall effects of the 1943–1952 Parícutin eruption on the radial growth of trees located near the top and flanks of the Tancítaro stratovolcano, ca.10 km southwest of the Parícutin volcano. We carried a dendrochronological sampling out in a temperate forest dominated by Pinus hartwegii and Abies religiosa trees. A ring-width chronology was built with 68 increment cores from 47 trees showed two statistically significant suppression events. The first event occurred from 1943 to 1946; it was caused by falling ash of the eruptive columns from Parícutin during the first 6 months of its eruption (February–June 1943). The second event occurred from 1818 to 1823, and it is attributed to the 1818 eruption of Volcán de Colima. The 1943–1946 suppression event observed in the tree rings demonstrates that trees are useful as palaeoenvironmental archives to evaluate the influence of volcanic eruptions in recent centuries in the Trans-Mexican Volcanic Belt. Our results indicate that falling ash immediately impacted the growth of trees in intertropical mountain zones of the Michoacan state located in the Michoacán-Guanajuato Volcanic Field. Such impact means that future eruptions may cause damage to crops and trees at the local and regional levels. Our findings contribute to evaluating volcanic hazards and risks in areas with active volcanoes and monogenetic volcanic fields.