The impact of Hurricane Frances (2004) on the invasive Australian pine (Casuarina equisetifolia L.) on San Salvador Island, the Bahamas

Abstract

On September 2, 2004 Hurricane Frances (Category 3) passed directly over San Salvador Island, The Bahamas. This event offered the opportunity to gather baseline data regarding the impact of hurricanes on populations of the invasive Australian pine (Casuarina equisettifolia L.) in the Bahamas. Results of vegetation surveys within both forest stands and beach environments suggest that the overall impact of this hurricane was minimal. Less than 13% of forest individuals and 17% of beach individuals surveyed were damaged, and the majority of damage was restricted to just one location for both the forest and beach study sites. The most common damage type within the forest sites was “snapped” trees (8%) and this primarily occurred within trees ranging in size from 7–12 cm in diameter. Browning of the entire foliage was the most common damage type within the beach sites (9.3%) but this damage type only occurred within tree sizes less than or equal to 90 cm in height. Thus it appears that Hurricane Frances had a negligible effect on Australian pine populations as a whole on San Salvador Island and that this disturbance event will probably not limit future population expansion. It is suggested that more powerful or more frequent hurricanes would be needed to significantly affect Australian pine populations on San Salvador Island. Similar patterns in damage should be expected with comparable hurricane events on other islands in the Bahamas and for other tropical beaches in which this species has invaded.