Characterizing potential wildland fire fuel in live vegetation in the Mediterranean region Silvano Fares, Sofia Bajocco, Luca Salvati, Nicolo Camarretta, Jean-Luc Dupuy, Gavriil Xanthopoulos, Mercedes Guijarro, Javier Madrigal, Carmen Hernando, Piermaria Corona To cite this version: Silvano Fares, Sofia Bajocco, Luca Salvati, Nicolo Camarretta, Jean-Luc Dupuy, et al.. Characterizing potential wildland fire fuel in live vegetation in the Mediterranean region. Annals of Forest Science, Springer Nature (since 2011)/EDP Science (until 2010), 2017, 74 (1), pp.1-14. 10.1007/s13595-016- 0599-5. hal-01604982 HAL Id: hal-01604982 https://hal.archives-ouvertes.fr/hal-01604982 Submitted on 6 Feb 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Copyright Annals of Forest Science (2017) 74: 1 DOI 10.1007/s13595-016-0599-5 REVIEW PAPER Characterizing potential wildland fire fuel in live vegetation in the Mediterranean region Silvano Fares1 & Sofia Bajocco 2 & Luca Salvati1 & Nicolò Camarretta3 & Jean-Luc Dupuy4 & Gavriil Xanthopoulos5 & Mercedes Guijarro6 & Javier Madrigal6 & Carmen Hernando6 & Piermaria Corona3 Received: 5 June 2016 /Accepted: 22 November 2016 /Published online: 6 February 2017 # INRA and Springer-Verlag France 2017 Abstract & Context Wildland fire management is subject to manifold & Key message Fuel moisture and chemical content affect- sources of uncertainty. Beyond the difficulties of predicting ing live plant flammability can be measured through lab- accurately the fire behavior, uncertainty stems from incom- oratory and field techniques, or remotely assessed. plete understanding of ecological susceptibility to fire. Standardization of methodologies and a better under- & Aims We aimed at reviewing current knowledge of (i) plant standing of plant attributes and phenological status can attributes and flammability: fuel moisture and chemical con- improve models for fire management. tent in leaves; (ii) experimental evaluation of flammability in the laboratory and in the field; and (iii) proxy evaluation of flammability: vegetation cover assessment at large scale, fuel seasonality, and biomass distribution using remote sensing Handling Editor: Barry Alan Gardiner and Light Detection and Ranging (LiDAR) techniques. Contribution of the co-authors Co-authors from CREA: contributed to & Methods We conducted a review of scientific literature from writing the paper and specifically to sections 4.2 and 4.3. the last two decades on the three selected issues, with a spe- Gavriil Xanthopoulos and colleagues from INIA: contributed to general drafting of the manuscript and in particular to section 3 with their exper- cific focus on the Mediterranean region. tise in flammability detection at multiple scales. & Results We have evidenced important knowledge gaps: (i) Jean-Luc Dupuy: contributed with general drafting of the manuscript and developing standardized methodologies for laboratory- and section 4.3. field-scale assessment of vegetation flammability; (ii) intro- ducing reliable approaches to test the impact of biogenic vol- * Silvano Fares atile organic compounds on fire spread; (iii) improving the [email protected] analysis of spatiotemporal changes in vegetation dynamics, acknowledging distinctive vegetation phenological status as 1 Council for Agricultural Research and Economics (CREA), Research a relevant driver affecting leaf biomass and moisture contents; Center for the Soil-Plant System, Rome, Italy and (iv) further exploring the processes that shape fuel dynam- 2 Council for Agricultural Research and Economics (CREA), Research ics to understand how fuel characteristics change over time Unit for Climatology and Meteorology Applied to Agriculture, and space. Rome, Italy & Conclusion We propose some improvements in the current 3 Council for Agricultural Research and Economics (CREA), Forestry knowledge of vegetation science and wildland fire ecology, Research Centre, Arezzo, Italy aiming to generate more realistic models and effective plan- 4 Ecologie des Forêts Méditerranéennes, Institut National de la ning in support of fire management in the Mediterranean Recherche Agronomique, Domaine Saint Paul, Site Agroparc, France basin. 5 Hellenic Agriculture Organization “Demeter”, Institute of Mediterranean Forest Ecosystems, Athens, Greece 6 Keywords Live fuel vegetation . Mediterranean forests . Department of Silviculture and Forest Management, National . Institute for Agricultural and Food Research and Technology Biogenic volatile organic compounds Plant moisture (INIA)-Forest Research Centre (CIFOR), Madrid, Spain Remote sensing . LiDAR 1 Page 2 of 14 Annals of Forest Science (2017) 74: 1 1 Introduction general classification may consider fuel loading or biomass per unit area as one of the main fuel attributes, it is evident While human factors are known to be crucial drivers of wild- that species-specific characteristics of vegetation may affect fires in Mediterranean countries, climate forcing still repre- flammability (Dimitrakopoulos 2001; Salvati and Ferrara sents the main determinant of wildfire ignition and spread 2015). In the last two decades, an increasing number (Bajocco et al. 2015; Barbati et al. 2015). Climate affects of studies have been carried out on such issues in both the spatial distribution of vegetation types and Mediterranean countries (Fig. 2), mainly in the West their fuel characteristics and the conditions for fire ig- and Central areas of the North Mediterranean region. nition and propagation in terms of weather patterns and Based on these premises, growing attention is devoted extremes (temperature, relative humidity, wind, precipi- to the intimate relationship between vegetation charac- tation, drought). Drought in particular affects live and teristics, fuel attributes, and local (or regional) changes dead fuel moisture content, thus influencing fire re- in climate regimes when developing realistic models gimes. As a consequence, a significant correlation be- supporting fire management. tween wildfires and the phenological status of vegeta- The purpose of this review is to contribute to these impor- tion has been widely observed in southern Europe tant and sometimes undervalued practices for describing and (Moreira et al. 2011; De Angelis et al. 2012). characterizing live vegetation as potential fuel. The rationale Warmer and drier future climates will exacerbate fire sever- of this work is to (1) review the most important findings from ity, intensity, and frequency for the fire-prone ecosystems, as scientific literature from the last two decades to highlight those those in the Mediterranean area (Lindner et al. 2010; Kolström traits of live Mediterranean vegetation which most likely re- et al. 2011; Fares et al. 2015). In this region, fire danger is late to flammability such as chemical and moisture content; likely to increase (Moriondo et al. 2006), and forest fires will (2) discuss the main approaches to measure these vegetation become an even larger threat to forestry, farming, and human properties mostly based on experimental measurements in the well-being in rural areas (Lindner et al. 2010). In this context, laboratory and in the field, up to local/regional studies using attributes of live vegetation and the capacity to properly char- remote sensing and Light Detection and Ranging (LiDAR) acterize live fuel become crucial for effective management techniques; and (3) identify knowledge gaps on the most planning (Fig. 1) aimed at mitigating fire danger and main- relevant issues that require further investigation based taining the capacity for Mediterranean forests to provide eco- on integrated approaches derived from both geo- system services (Tilman et al. 2000;Keane2013). While a ecology and forest science. Fig. 1 Simple conceptual model of the major anthropogenic factors the US National Science and Analysis Team (NSAT 2012), the involved in wildland fire management, principal interacting model shows in red the fire management activity that is the object processes, and values affected by fire. Adapted from a report of of our discussion Annals of Forest Science (2017) 74: 1 Page 3 of 14 1 still allow production of biogenic volatile organic compounds (BVOCs), CO, CH4, and particles. Fuel consumption broadly follows biome distributions with low biomass biomes such as grasslands and savannas burning less fuel than high biomass forest types (Van der Werf et al. 2010). Wildland fires have the potential to release massive amount of carbon into the atmosphere. The majority of carbon emitted from forest fires is released as CO2 with global estimates close to 2000 Tg (C) year−1 (Van der Werf et al. 2010). The chem- ical content in leaves is species-specific and determines dif- Fig. 2 Number of scientific publications found on Scopus from 1996 to 2015 with the following search criteria: (wildfire OR forest fire) AND ferent properties of flammability, which include ignitibility Mediterranean AND (flammability OR live fuels OR live vegetation (timing of the fuel ignition), combustibility (how well