Flammability traits of fynbos species with different post-fire regeneration strategies
Wild fire is an important disturbance regime that shape global biome distributions and maintain the structure, function and biological diversity of plant communities in fire-prone environments. Physical, chemical and architectural properties are known to affect plant flammability, but few studies explore how these traits contribute to fire properties at the individual level and how flammability is influence by regeneration strategy. The flammability and traits that contribute to it is investigated in 15 co-occurring fynbos and forest species with burning experiments performed at Bain's Kloof Pass, Western Cape of South Africa. Eight species are characterised by fire-stimulated (mostly seeders) and seven by non-fire-stimulated recruitment (mostly resprouters). Results across all species are consistent with other studies which indicate that the proportion of dead and fine fuel is significant predictors of flammability. Significantly higher flame temperatures and values for % fuel burned were recorded for FSR's relative to NFSR's and these differences are attributed to significant differences in % fuel dead, fuel bed porosity and packing ratio. This is consistent with the hypothesis that flammability is most like to be selected for in fire-stimulated recruiters (first colonisers after fire) where a combination of increased flammability and recurrent success enhance their fitness in the fire-prone environment. This study indicates that cultivation of the highly flammable species E. rhinocerotis, Stoebe sp., M. muricata, Erica sp. and P. amplexicaulus on urban fringes should avoided to reduce fire-risk and thus increase human safety.
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