Are long-unburnt eucalypt forest patches important for the conservation of plant species diversity?
Question: Are long-unburnt patches of eucalypt forest important for maintainingfloristic diversity?Location: Eucalyptus forests of southeastern New SouthWales, Australia.Methods: Data from 976 sites representing a range of fire history from threemajor vegetation formations ¿ shrubby dry sclerophyll forest (SF), grassy dry SFand wet SF ¿ were analysed. Generalized linear models were used to examinechanges in species richness with increasing time since wildfire and analysis ofsimilarities to examine changes in community composition. Chi-squared testswere conducted to examine the distribution of individual species across fourtime since fire categories.Results: Plant species relationships to fire varied between the three formations.Shrubby dry SF supported lower plant species richness with increasing timesince wildfire and this was associated with shifts in community composition.Grassy dry SF showed significant shifts in community composition and speciesrichness in relation to time, with a peak in plant species richness 20¿30 yr postfire (either prescribed fire or wildfire). Wet SF increased in species richnessuntil 10¿20 yr post wildfire then displayed a general declining trend. Speciesrichness in each vegetation type was not related to the fire frequencies and fireintervals observed in this study.Conclusions: Long-unburnt (30¿50 yr post wildfire) forests appeared to play aminor role in the maintenance of plant species diversity in dry forest systems,although this was more significant in wet forests. Maintenance of a range of fireages within each vegetation formation will assist in maintaining floristicdiversity within regions.