ALBERT

Description:    Palaeoclimate proxies have demonstrated links between climate changes and volcanic activity. However, not much is known about the impact of volcanic eruptions on forest productivity. Here we used tree-ring width and annually resolved carbon and oxygen isotopic records from tree rings of Araucaria araucana (Molina) K. Koch, providing a centennial-scale reconstruction of tree ecophysiological processes in forest stands nearby the Lonquimay Volcano (Chile). We observed a mean decrease in tree-ring width following the major eruption of 1988 – 1990 (with aerosol emission), most probably caused by the modified ecological conditions due to acid rain and ash deposition, while a generally negative relationship between δ 13 C and δ 18 O would point to a decline in humidity and precipitation. More negative δ 13 C and lower δ 18 O values (positive correlation) following the major eruption of 1887–1890 (without aerosol emission) would suggest high stomatal conductance and moisture availability, though tree-ring width (and probably photosynthetic rate) was unaltered. At least for this sample of trees, in the case of eruption with large tephra emission, the beneficial effect of aerosol light scattering on tree productivity appears to be outweighed by the detrimental effect of eruption-induced toxic deposition. Signals of the two major eruptions of the past 200 years at Lonquimay were present in tree rings of nearby A. araucana . No unique response of tree functions to volcanic eruptions can be expected, but rather (1) the variable volcanic properties and (2) the complex interplay of diffuse light increase (aerosol scattering), air temperature decrease (cloud shading), and toxic deposition impact (volcanic ash), makes any prediction of tree growth and ecophysiological response very challenging. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s00468-012-0749-9 Authors Roberto Tognetti, Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Contrada Fonte Lappone, 86090 Pesche, Italy Fabio Lombardi, Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Contrada Fonte Lappone, 86090 Pesche, Italy Bruno Lasserre, Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Contrada Fonte Lappone, 86090 Pesche, Italy Giovanna Battipaglia, Dipartimento di Scienze Ambientali, Seconda Università di Napoli, Via Vivaldi, 81100 Caserta, Italy Matthias Saurer, PSI, Paul Scherrer Institut, 5232 Villigen, Switzerland Paolo Cherubini, WSL, Swiss Federal Institute for Forest, Snow and Landscape Research, 8903 Birmensdorf, Switzerland Marco Marchetti, Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Contrada Fonte Lappone, 86090 Pesche, Italy Journal Trees - Structure and Function Online ISSN 1432-2285 Print ISSN 0931-1890