Jesús Eduardo Sáenz-Ceja;Blanca Lizeth Sáenz-Ceja;J. Trinidad Sáenz-Reyes;Diego R. Pérez-Salicru

Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701 Col. Ex hacienda San José de la Huerta, 58190, Morelia, Mexico;Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701 Col. Ex hacienda San José de la Huerta, 58190, Morelia, Mexico;Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Campo Experimental Uruapan, Av. Latinoamericana 1101, Col. Revolución, 60500, Uruapan, Mexico;Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701 Col. Ex hacienda San José de la Huerta, 58190, Morelia, Mexic

Age structure;Dendrochronology;Lava flow;Primary succession;Tropical montane forest;PLANT SUCCESSION;LAVA FLOWS;MOUNT KOMA;COLONIZATION;VEGETATION;RECRUITMENT;WASHINGTON;DYNAMICS;OREGO

Volcanic eruptions have large effects on forest ecosystems and create new substrates, triggering primary succession processes. The Paricutín volcano, born in central-western Mexico, erupted between 1943 and 1952. After the cessation of the eruptive activity, plant colonization began on the lava flows and tephra deposits, including the conifer species that dominate the surrounding mature forests. This study aims to reconstruct the history of the establishment of conifer trees on the substrates created by the Paricutín eruption. 16 sampling plots were established along three transects with northern, southern, and south-western aspects, located every 250 ​m from the preserved forest to the volcanic cone. Increment cores from 400 conifer trees were extracted and their age was determined by cross-dating annual tree rings. The order of the species colonization and the tree establishment, abundance, and dominance patterns were characterized. Also, the influence of the distance from the mature forests and the inter-annual climatic conditions on the temporal tree establishment pattern was evaluated. Eight pine and one fir species have been established since 1970, only 18 years after the end of the eruptive period. However, tree establishment increased by 12.9% annually after 1995, with the youngest tree in our sample getting established in 2015. We did not find a well-defined temporal and spatial pattern of species arrival, which suggests that colonization occurred randomly, although the four pine species that were established early became the most abundant and dominant. Tree establishment was not influenced by the distance from the mature forest, and wet inter-annual conditions did not enhance pulses of tree recruitment, exhibiting a continuous tree establishment pattern. Conifer species have shown a great capacity for colonizing volcanic substrates created by the Paricutín eruption, which suggests that tropical montane conifers can regenerate rapidly under high-magnitude disturbances. These findings support the use of these forest species for ecological restoration.