The effects of fire and predators on the long-term persistence of an endangered shrub, Grevillea caleyi Original Research Article

Grevillea caleyi is an endangered plant species with a restricted range lying partly within Ku-ring-gai Chase and Garigal National Parks in NSW, Australia. The principle threatening processes affecting G. caleyi are habitat destruction and adverse fire regimes combined with high levels of seed predation. A stochastic, spatially explicit, individual-based model was constructed to investigate the population dynamics of small populations of the species and to determine the impact of a variety of management strategies. Results of model simulations indicate there is a high risk of population decline and local extinction in remnant sites with small populations under current management regimes. The most effective fire management strategy is to schedule fires that burn 20–100% of sub-populations every 5–15 years, in combination with reduced predation rates. When predation management strategies are employed in conjunction with a structured fire regime, then a 20–30% reduction in predation rates can improve the chance of long-term persistence substantially.