Changements saisonniers dans l'altération anthropique du régime d'incendie : au-delà du forçage climatique
| Autor: | Fréjaville, T., Curt, T. |
|---|---|
| Přispěvatelé: | Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Environmental Research Letters Environmental Research Letters, IOP Publishing, 2017, 12 (3), 13 p. ⟨10.1088/1748-9326/aa5d23⟩ |
| ISSN: | 1748-9326 |
| DOI: | 10.1088/1748-9326/aa5d23⟩ |
| Popis: | International audience; Human activities have altered fire regimes for millennia by suppressing or enhancing natural fire activity. However, whether these anthropogenic pressures on fire activity have exceeded and will surpass climate forcing still remains uncertain. We tested if, how and the extent to which seasonal fire activity in southern France has recently (1976-2009) deviated from climate-expected trends. The latter were simulated using an ensemble of detrended fire-climate models. We found both seasonal and regional contrasts in climatic effects through a mixture of drought-driven and fuel-limited fire regimes. Dry contemporary conditions chiefly drove fire frequency and burnedarea, although higher fire activity was related to wetter conditions in the last three years.Surprisingly, the relative importance of preceding wet conditions was higher in winter than in summer, illustrating the strong potential dependency of regional fire-climate relationships on the human use and control of fires. In the Mediterranean mountains, warm winters and springs favour extensive fires in the following dry summer. These results highlight that increasing drynesswith climate change could have antagonistic effects on fire regime by leading to larger fires in summer (moisture-limited), but lower fire activity in winter (fuel-limited fire regime).Furthermore, fire trends have significantly diverged from climatic expectations, with a strong negative alteration in fire activity in the Mediterranean lowlands and the summer burned area in the mountains. In contrast, alteration of winter fire frequency in the Mediterranean andTemperate mountains has shifted from positive to negative (or null) trends during the mid-1990s, a period when fire suppression policy underwent major revisions. Our findings demonstrate that changes in land-use and fire suppression policy have probably exceeded the strength of climate change effects on changing fire regime in southern Europe, making regionalpredictions of future fires highly challenging |
| Databáze: | OpenAIRE |
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