Assessment of Forest Fire Rating Systems in Typical Mediterranean Forest, Crete, Greece

Abstract. The Fire Weather Index (FWI) module was tested under the Mediterranean- type conditions of Crete (Greece) for the two fire seasons 2008–2009. High correlations were found between the Fine Fuel Moisture Code (FFMC) and the Duff Moisture Code (DMC. The Drought Code (DC) was insignificantly correlated with the soil moisture content. No significant correlation was found between the area burned by wildfires and any component of the FWI system during the studied period, unlike fire occurrence with which most of the components were highly correlated. Meanwhile, the Keetch-Byram Drought Index (KBDI) of the American Forest Fire Danger Rating System (NFFDRS) was also examined under the same conditions. It provided a useful means of monitoring general wetting and drying cycles, but is inadequate for indicating daily fire danger throughout the fire season in our region. Weak correlations between the KBDI- the fire occurrence and the area burned were found for the two fire seasons studied-2008–2009. Correlations between the KBDI and litter, duff and soil did not give statistically sound results. On the contrary, the KBDI seemed to predict with high accuracy the moisture content of three annual plants (Piplatherum miliaceum, Parietaria diffusa, Avena sterillis) with a shallow rooting system of Pinus halepensis forest understory in the region. This indicated that the index was adequate, to a certain extent, to represent the upper soil layers' water status, while it is unsuitable to predict needles moisture content of Pinus halepensis, which has a deep rooting system.