Population Ecology of Waratahs, Telopea speciosissima (Proteaceae): Implications for Management of Fire-prone Habitats

Andrew J. Denham, Tony D. Auld

Abstract


Waratah (Telopea speciosissima) post-fire floral displays are a prominent feature of the landscape in Royal National Park and elsewhere in southeastern Australia, but factors governing the persistence of the species are poorly known. We examined long term patterns of fecundity, recruitment and survival of waratahs in Royal NP in relation to two major wildfires. Flowering occurred mainly over 3 years following both the 1994 and 2001 fi res, but fewer plants flowered, fewer seeds were produced and fewer seedlings established after the 2001 fi re. After the 1994 fire, limited seed dispersal resulted in most seedlings establishing near fruiting individuals. Only 14% of the plants that established as seedlings after the 1994 fire survived the 2001 fire. At the time of the 2001 fi re, these plants were 4-6 years old and post-fire survival was highest in older plants. A logistic model predicts that it would take 5.9 (95% CI 5.4-7.5) years of growth after germination for plants to have greater than 25% survival probability if burnt (equivalent to a fire return period of about 9 years). Waratahs are long lived, have long primary juvenile periods and occasional opportunities for recruitment. Each fire may not lead to successful recruitment. While recruitment failure after one or more fires may not be significant, understanding the proximate factors that limit recruitment is important to predict the impact of long term changes such as altered fire regimes under a changing climate.

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