j.g. pausas' blog

Fire regimes and vegetation patterns are the product of both climate and humans (Marlon et al. 2008, Pausas & Keeley 2009). For instance, contemporary ignitions are very often linked to human behaviour (arson, negligence, etc.) and fire sizes may be related to landscape fragmentation and suppression efforts; however, the climatic signal on fire regimes is still evident (e.g,. dry summers, Pausas 2004; during heat waves, etc.). A recent paper documents this complex interaction in shaping Holocene fire regimes in the Mediterranean Basin: Climate, microclimate (topography) and human pressure are factors that need to be considered for understanding changes in both vegetation and fire activity during the Holocene of south Europe (Gil-Romera et al. 2010).

• Marlon et al. 2008. Climate and human influences on global biomass burning over the past two millennia. Nature Geoscience, 1, 697-702.
• Pausas J.G. 2004. Changes in fire and climate in the eastern Iberian Peninsula (Mediterranean basin). Climatic Change, 63, 337-350. [doi | pdf]
• Pausas J.G. & Keeley J.E. 2009. A burning story: The role of fire in the history of life. BioScience, 59, 593-601. [doi | pdf]
• Gil-Romera et al. 2010. Fire regime in Southern Iberia: the long-term role of fire as landscape modeller in a western Mediterranean region. Quat. Sci. Rev. 29: 1082-1092. [doi | pdf]

Age (cal Kyr BP)

Figure: Synthetic pollen percentage diagrams for Baza mountains (1900 m asl, Southeastern Spain), with the Normalised Charcoal (NCHAR, right) and millennial averaged Fire Activity Anomalies (FAA, left) shown on top. (XER: xerophytes, MES: Mesophytes, Querdec: Deciduous oaks, Querever: Evergreen oaks, Pining: Pinus nigra + P. sylvestris). The increase of fire activity is assotiated to the decrease of Pinus nigra (non-serotinous thin-barked pines) and the increase of Poaceae and xerophytes. For mode details see Gil-Romera et al. (2010).