The effects of prescribed burning on Pinus halepensis Mill. as revealed by dendrochronological and isotopic analyses Giovanna Battipaglia ⇑ , Sandro Strumia, Assunta Esposito, Elisabetta Giuditta, Carmina Sirignano, Simona Altieri, Flora A. Rutigliano Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, 81100 Caserta, Italy article info Article history: Received 3 June 2014 Received in revised form 10 September 2014 Accepted 10 September 2014 Keywords: Prescribed burning Dendrochronology Aleppo pine Tree physiology abstract Prescribed burning is used in several countries to manage Mediterranean ecosystems mainly to reduce the risk of high-intensity wildfires. As the physiological response of overstory trees to prescribed burning has received scant attention in the scientific literature, the main objective of this study was to determine whether prescribed burning impacts the growth and ecophysiological responses of stands of the Aleppo pine (Pinus halepensis Mill.). Basal area, carbon, oxygen, and nitrogen isotopic compositions were ana- lyzed before and after the burning event at an experimental site and at a nearby unburned area used as control, both in the co-existing old dominant P. halepensis trees and in the youngest individuals. Our results suggest that the oldest pines experienced more favorable growing conditions after prescribed burning probably through higher water and nutrient availability, at least in the short term. The youngest individuals mostly likely suffered from an increase in competition with the older co-existing trees. These differences in physiology suggest the need to understand and evaluate, in the prescribed burning man- agement plans, the growth and survival of burned trees of different ages in order to maximize the positive effects and reduce possible negative impacts. Ó 2014 Elsevier B.V. All rights reserved. 1. Introduction Prescribed burning is increasingly being recognized and incor- porated as a management tool for wildfire reduction in several European forests (Fernandes et al., 2013), especially in the Mediter- ranean regions where wild and man-induced fires represent a major environmental problem, causing a large destruction of for- ests and a considerable increase of greenhouse gas emissions (Moriondo et al., 2006). Prescribed burning can be described as the careful application of fire under specific fuel and weather con- ditions to meet specific objectives and long-term management goals (Wade and Lunsford, 1989), such as silvicultural improve- ment, control of insects and diseases, habitat management, biodi- versity conservation and, especially, the reduction of the risk of wildfires (Fernandes and Botelho, 2003). Several studies investi- gated the sustainability of prescribed fire in reducing wildfire haz- ard, avoiding negative effects on different ecosystem components, such as soil (Catalanotti et al., 2010), seeds (Keyser et al., 2012), shrubs (Fernandes et al., 2013) and trees (Fernandes and Rigolot, 2007). Ducrey et al. (1996), studying the ecophysiological responses of Pinus halepensis to heat-caused stem injury, verified that no trees died with less than 85% of the trunk circumference destroyed by fire. In addition, reduction in tree mortality and crown scorch were reported for the North American Pinus ponder- osa stands that were treated by prescribed burning some years before a natural wildfire occurred (Wagle and Eakle, 1979; Martin et al., 1988; Pollet and Omi, 2002). Indeed, moderate damages seems to be recorded after experimental fires in several European pines species (Fernandes et al., 2008) even if quantifica- tion of the influence of prescribed burning on trees’ growth and ecophysiology remains elusive. Understanding the effect of pre- scribed burning in the short and mid-term on tree productivity and on plant ecophysiological responses is of crucial importance for fuel management plans and burning prescriptions, especially in widespread flammable plantations, such as P. halepensis stands. Aleppo pine (P. halepensis) is one of the most extensively studied Mediterranean pine (Ne’eman, 2000), abundant in fire-prone habitats within the Mediterranean basin and considered highly vulnerable to fire events (Trabaud, 2000; Kazanis and Arianoutsou, 2004). Recently, it has been demonstrated not only that P. halepensis is able to survive to wildfires (Fournier et al., 2013) but also that with its great plasticity it has developed various anatomical and ecophysiological adaptations to past fire events (De Micco et al., 2013; Battipaglia et al., 2014b). http://dx.doi.org/10.1016/j.foreco.2014.09.010 0378-1127/Ó 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding author. Tel.: +39 0823274647; fax: +39 0823274605. E-mail address: giovanna.battipaglia@unina2.it (G. Battipaglia). Forest Ecology and Management 334 (2014) 201–208 Contents lists available at ScienceDirect Forest Ecology and Management journal homepage: www.elsevier.com/locate/foreco