Are seed dispersal and predation in fire-sensitive Persoonia species (Proteaceae) associated with rarity?

Seed dispersal and predation are key processes affecting the colonization and extinction of populations in fire-prone environments. If these processes influence distribution and abundance, rare species may be expected to have less seed removal and/or greater seed predation than common congeners. I compared seed removal and predation under plants in two closely related pairs of fire-sensitive common and rare Persoonia species with fleshy fruits in two replicate populations of each species. Seed removal by macropods was significantly greater in the two common species (>50% seeds/plant) than in their rare congeners (<25%). There was no overall effect of rarity on seed predation by rodents, but there were significantly more seeds of the rare Persoonia mollis subspecies maxima eaten than of the other three species. Plant size was the only attribute measured that was significantly correlated with seed removal (r = 0:50). After including plant size as a covariate in the analysis, I still detected a significant effect of rarity on seed removal. High levels of seed removal were sustained in both small and large populations of the common Persoonia lanceolata, suggesting that population size may not be contributing to the differences between these common and rare species. The common-rare difference in the seed removal of Persoonia species seems robust across several plant and population attributes.