A Bayesian Modelling of Wildfires in Portugal

In the last decade wildfires became a serious problem in Portugal due to different issues such as climatic characteristics and nature of Portuguese forest. In order to analyse wildfire data, we employ beta regression for modelling the proportion of burned forest area, under a Bayesian perspective. Our main goal is to find out fire risk factors that influence the proportion of area burned and what may make a forest type susceptible or resistant to fire. Then, we analyse wildfire data in Portugal during 1990-1994 through Bayesian beta models t

Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment

As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced

Lightning and Fires in the Northwest Territories and Responses to Future Climate Change

Lightning and fire characteristics within the Northwest Territories (NWT) jurisdiction of the Mackenzie Basin between 1994 and 1999 are examined using data from the lightning detection network operating in the NWT and from the national Large Fire Database maintained by the Canadian Forest Service. The convective storm season with associated lightning activity over this region is short but intense, with a strong peak in cloud-to-ground lightning during July. The maximum area of lightning activity is influenced by local moisture sources and by topography. The diurnal distribution of cloud-to-ground flashes indicates that most of the lightning was linked to thunderstorms initiated by daytime heating. The lightning-initiated fire occurrences peaked during July, while much of the burned area was produced in June. The longer, warmer, and drier summer seasons projected to result from climate change are expected to increase the frequency and intensity of forest fires by the end of the 21st century. Their considerable consequences for forests and wildlife make these changes a concern for northern communities, forest managers, and wildlife biologists.Les caractéristiques des éclairs et des incendies enregistrés dans le bassin du Mackenzie entre 1994 et 1999 sont examinées à la lumière de données obtenues à partir du réseau de détection des éclairs des Territoires du Nord-Ouest et de la Base de données sur les gros incendies du Service canadien des forêts. Dans cette région, la saison des orages de convection et les éclairs qui en découlent est courte, mais intense, les éclairs nuages-sol atteignant leur point le plus élevé en juillet. L’aire maximale visée par les éclairs est influencée par les sources d’humidité et la topographie locales. La répartition diurne d’éclairs nuages-sol indique que la plupart des éclairs provenaient des orages attribuables à la chaleur de la journée. Les incendies découlant d’éclairs ont atteint leur point culminant en juillet, tandis que la plupart des régions brûlées l’ont été en juin. Les étés plus longs, plus chauds et plus secs susceptibles de résulter des changements climatiques devraient augmenter la fréquence et l’intensité des feux de forêt d’ici la fin du XXIe siècle. Leurs répercussions considérables sur les forêts et sur la faune sont une source de préoccupation pour les collectivités du Nord, les experts forestiers et les biologistes de la faune