title: Wildfire risk for main vegetation units in a biodiversity hotspot: modeling approach in New Caledonia, South Pacific.
abstract: Wildfire has been recognized as one of the most ubiquitous disturbance agents to impact on natural environments. In this study, our main objective was to propose a modeling approach to investigate the potential impact of wildfire on biodiversity. The method is illustrated with an application example in New Caledonia where conservation and sustainable biodiversity management represent an important challenge. Firstly, a biodiversity loss index, including the diversity and the vulnerability indexes, was calculated for every vegetation unit in New Caledonia and mapped according to its distribution over the New Caledonian mainland. Then, based on spatially explicit fire behavior simulations (using the FLAMMAP software) and fire ignition probabilities, two original fire risk assessment approaches were proposed: a one-off event model and a multi-event burn probability model. The spatial distribution of fire risk across New Caledonia was similar for both indices with very small localized spots having high risk. The patterns relating to highest risk are all located around the remaining sclerophyll forest fragments and are representing 0.012% of the mainland surface. A small part of maquis and areas adjacent to dense humid forest on ultramafic substrates should also be monitored. Vegetation interfaces between secondary and primary units displayed high risk and should represent priority zones for fire effects mitigation. Low fire ignition probability in anthropogenic-free areas decreases drastically the risk. A one-off event associated risk allowed localizing of the most likely ignition areas with potential for extensive damage. Emergency actions could aim limiting specific fire spread known to have high impact or consist of on targeting high risk areas to limit one-off fire ignitions. Spatially explicit information on burning probability is necessary for setting strategic fire and fuel management planning. Both risk indices provide clues to preserve New Caledonia hot spot of biodiversity facing wildfires.
authors.affiliation: I.R.D. UMR ESPACE DEV BP A5, 98848, Nouméa Cedex, New Caledonia.
authors.forename: Céline
authors.initials: C
authors.lastname: Gomez
authors.affiliation: I.R.D. UMR ESPACE DEV BP A5, 98848, Nouméa Cedex, New Caledonia.
authors.forename: Morgan
authors.initials: M
authors.lastname: Mangeas
authors.affiliation: Irstea, UR EMAX Ecosystèmes Méditerranéens et Risques 13182 Aix en Provence, Cedex 05, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Curt
authors.affiliation: Diversités biologique et Fonctionnelle des Écosystèmes Terrestres, Institut Agronomique néo-Calédonien (IAC) BP A5, 98800, Nouméa, New Caledonia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ibanez
authors.affiliation: UMR AMAP, Laboratoire de Botanique et d'Ecologie Végétale Appliquées, Herbarium NOU, Centre IRD BPA5, 98848, Nouméa, New Caledonia ; IRD, UMR AMAP 34398, Montpellier, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Munzinger
authors.affiliation: EA 4242 Centre for New Pacific Studies (CNEP), University of New Caledonia Nouméa, New Caledonia.
authors.forename: Pascal
authors.initials: P
authors.lastname: Dumas
authors.affiliation: I.R.D. UMR ESPACE DEV BP A5, 98848, Nouméa Cedex, New Caledonia.
authors.forename: André
authors.initials: A
authors.lastname: Jérémy
authors.affiliation: I.R.D. UMR ESPACE DEV BP A5, 98848, Nouméa Cedex, New Caledonia.
authors.forename: Marc
authors.initials: M
authors.lastname: Despinoy
authors.affiliation: Centre de Bio-Archéologie et Ecologie, UMR 5059, EPHE (Laboratoire PALECO) 34090, Montpellier, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Hély
keywords: Biodiversity loss; FLAMMAP; NEW Caledonia; burn probability; fire impact; spatially explicit modeling; wildfire risk assessment