Format: ORAL

Cristopher Fernndez-Blas1, Paloma Ruiz-Benito1, Antonio Gazol2, Elena Granda1, Eva Sambls1, Irene Granado-Daz1, Patricia Gonzlez-Daz3, Miguel A. Zavala1, C. Valeriano2, J. Julio Camarero2

1 Universidad de Alcalá, Alcalá de Henares, Spain 2 Instituto Pirenaico de Ecología (IPE), Consejo Superior de Investigaciones Científicas (CSIC), Zaragoza, Spain 3 Centro de Investigaciones sobre Desertificación (CIDE, CSIC-UV-GV), Valencia, Spain

Resin extraction from pine trees was an important economic activity for most of the 20th century in forested countries such as Spain. However, the decrease in resin prices and massive rural migration to cities led to their abandonment in the 1960s-1970s. Reduced tree growth is often observed after long periods of resin tapping, but it is unknown how these formerly tapped stands would respond to recent climate warming and aridification. In Spain, maritime pine (Pinus pinaster) was extensively exploited for resin extraction in several regions subjected to increasing drought stress. To understand the differential growth and their responses to climate between resin tapped and non-resin tapped trees, we sampled three historically tapped maritime pine stands in Teruel, eastern Spain, where tapping finished in the 1970s. We extracted and measured cores from 51 resin-tapped and 47 non-resin tapped trees, and compared their growth trends and responses to climate variables and a drought index. Basal area increment was used to measure annual growth. We performed linear mixed regression models to understand the differential responses of resin tapped and non-resin tapped trees to climate variables, including as covariates tree size, age and the resin tapped status. In the study area, climate has progressively warmer and dried since the 1970s. Tree growth was higher in resin tapped trees compared to non-resin tapped trees, which were generally younger. Formerly tapped trees responded more to drought severity than non-tapped trees and were also more negatively impacted by warmer summer temperature. Our results suggest that the legacy effects of previous management can constrain tree responses to climate change.