title: Effects of prescribed burning on ecophysiological, anatomical and stem hydraulic properties in Pinus pinea L.
abstract: Prescribed burning (PB) is a widespread management technique for wildfire hazard abatement. Understanding PB effects on tree ecophysiology is key to defining burn prescriptions aimed at reducing fire hazard in Mediterranean pine plantations, such as Pinus pinea L. stands. We assessed physiological responses of adult P. pinea trees to PB using a combination of dendroecological, anatomical, hydraulic and isotopic analyses. Tree-ring widths, xylem cell wall thickness, lumen area, hydraulic diameter and tree-ring δ(13)C and δ(18)O were measured in trees on burned and control sites. Vulnerability curves were elaborated to assess tree hydraulic efficiency or safety. Despite the relatively intense thermal treatment (the residence time of temperatures above 50 °C at the stem surface ranged between 242 and 2239 s), burned trees did not suffer mechanical damage to stems, nor significant reduction in radial growth. Moreover, the PB did not affect xylem structure and tree hydraulics. No variations in (13)C-derived water use efficiency were recorded. This confirmed the high resistance of P. pinea to surface fire at the stem base. However, burned trees showed consistently lower δ(18)O values in the PB year, as a likely consequence of reduced competition for water and nutrients due to the understory burning, which increased both photosynthetic activity and stomatal conductance. Our multi-approach analysis offers new perspectives on post-fire survival strategies of P. pinea in an environment where fires are predicted to increase in frequency and severity during the 21st century.
authors.affiliation: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy Ecole Pratique des Hautes Etudes (PALECO EPHE), Centre for Bio-Archaeology and Ecology, Institut des Sciences de l'Evolution, University of Montpellier 2, F-34090 Montpellier, France CMCC, Euro-Mediterranean Center on Climate Change, via Augusto Imperatore 16, 73100 Lecce, Italy giovanna.battipaglia@unina2.it.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Battipaglia
authors.affiliation: Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy.
authors.forename: Tadeja
authors.initials: T
authors.lastname: Savi
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco (TO), Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Ascoli
authors.affiliation: Department of Land, Environment, Agriculture and Forestry, University of Padua, Via dell'Università 16, 35020 Legnaro (PD), Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Castagneri
authors.affiliation: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy.
authors.forename: Assunta
authors.initials: A
authors.lastname: Esposito
authors.affiliation: Institut für Botanik Universität Innsbruck, Sternwartestr. 15, 6020 Innsbruck, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Mayr
authors.affiliation: Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Nardini
mesh_terms: D004463:Ecology; D005390:Fires; D010103:Oxygen Isotopes; D028223:Pinus / Q000033:anatomy & histology* / Q000378:metabolism*; D018547:Plant Stems / Q000033:anatomy & histology / Q000378:metabolism; D054046:Plant Stomata / Q000378:metabolism; D018526:Plant Transpiration / Q000502:physiology; D014867:Water / Q000378:metabolism; D052584:Xylem / Q000378:metabolism
chemical_list: D010103:Oxygen Isotopes; D014867:Water
keywords: carbon isotope; cavitation; intrinsic water use efficiency; oxygen isotope; radial growth; stone pine; wood anatomy; xylem hydraulic efficiency