Relationships between seasonal patterns of live fuel moisture and meteorological drought indices for Mediterranean shrubland species

摘要

Measurements of seasonal patterns of live fuel moisture content and ignitability (in terms of time to ignition)of four Mediterranean shrub species were performed in North Western Sardinia (Italy). Relationships between the twovariables were evaluated. Relationships between live fuel moisture content and environmental conditions (i.e. rainfall, airtemperature and soil moisture) were analysed. Two groups of species were identified in relation to the different responseof live fuel moisture content to seasonal meteorological conditions. Seasonal patterns of live fuel moisture content werealso compared with five meteorological drought indices: Duff Moisture Code and Drought Code of the Canadian ForestFire Weather Index System, Keetch-Byram Drought Index, Canopy Drought Stress Index and Cumulative Water BalanceIndex. In addition, the capability of the meteorological drought indices to describe moisture variation for each specieswas evaluated. Although the Drought Code was formulated to describe changes in the moisture content of dead fuel, itwas shown to have a good potential for modelling live fuel moisture variation of a group of shrubland species that aresensitive to meteorological conditions, with a clear and large decrease of moisture content during the drought season.