The impact of a needleminer (Epinotia subsequana) outbreak on radial growth of silver fir (Abies alba) in the Aragón Pyrenees: A dendrochronological assessment
Abstract:We report the first dendrochronological assessment on the effects of the Epinotia subsequana (Lepidoptera: Tortricidae) needleminer on Abies alba forests in the Aragón Pyrenees (northeastern Spain), near the southwestern distribution limit of A. alba. We built local residual ring-width chronologies, in fifteen A. alba stands, using dendrochronological techniques. We found a strong decrease in radial growth in the 20th century, during the 1996–98 period, only at the sites AS (Paco Asieso, 42°39' N, 00°17' W) and DI (Diazas, 42°38' N, 00°06' W). There were previous surveys of E. subsequana outbreaks and fir defoliation, in the studied sites area, in 1995–96. They showed that the radial-growth suppression was caused by E. subsequana. We compared radial growth in the non-defoliated stands with mean regional chronology. The greatest decline in radial growth was in 1996–97. Thus, there was a 1–2 year lag in radial growth suppression following the defoliation. The recovery of radial growth occurred in 1998–99.
Document Type: Research Article
Affiliations: Unidad de Sanidad Forestal, Servicio Provincial de Medio Ambiente de Zaragoza, Gobierno de Aragón, Zaragoza, SpainUnidad de Recursos Forestales, Servicio de Investigación Agroalimentaria, Gobierno de Aragón, Zaragoza, SpainDept. d'Ecologia, Fac. de Biologia, Universitat de Barcelona, Barcelona, Spain
Publication date: July 1, 2003