Moisture content variation of ground vegetation fuels in boreal mesic and sub-xeric mineral soil forests in Finland

Forest fire risk in Finland is estimated with the Finnish Fire Index (FFI), which predicts fuel moisture content (FMC) of forest floor. We studied FMC variation four typical ground vegetation fuels, Pleurozium schreberi, Hylocomium splendens, Dicranum spp., and Cladonia raw humus mature recently clear-cut stands. Of these, six were sub-xeric Pinus sylvestris stands, mesic Picea abies analysed ability FFI to predict compared it widely applied Canadian Weather (FWI). found that addition stand characteristics, layer was highly dependent on species so moistest, driest. In layer, differences among small. Overall, FWI a slightly better predictor than FFI. While generally predicted well, shape relationship varied species. The use auxiliary variables thus has potential improving predictions ignitions risk. Knowledge could also benefit planning timing prescribed burns.