INVASIVE EXOTICS IN THE PRESERVE

Many of the plants, and a few of the animals, in the Preserve are not native to south
Florida. A few of the plants are invasive, and we have invested considerable energy in removing them.

Australian Pine (Casuarina equisetifolia)
This invasive tree is a management problem throughout south Florida. It produces root nodules that house nitrogen-fixing algae, making it able to colonize sites very poor in nutrients. In addition, its shallow and wide-spreading roots produce "suckers" that quickly grow into independent trees. Thus, a single tree can quickly grow into a colony-a single forest. These trees were a problem during the early history of the Preserve, but were confined to an area by applying herbicide to the small suckers. The earlier large trees were girdled and killed over five years ago. There are a few small trees in various areas of the Preserve that should be removed soon.

Brazilian Pepper (Schinus terebinthifolius)
This invasive tree is the most serious exotic plant pest in southeast Florida. The tree is tolerant of a wide variety of conditions, including salinity and some shade. Its bright red berries are avidly consumed by many songbirds, who disperse the seeds in their droppings. Once established, as at the north end of the Preserve, Brazilian Pepper forms a dense and uniform stand that crowds out all other vegetation. This is the single most serious exotic problem in the Preserve.

Burma Reed (Neyraudia neyraudiana)
This large (2-3 meter high) grass spreads through wind-blown seeds and sprouts from its horizontally growing rhizomes. It can quickly dominate open sites, but is intolerant of shade. It has become a problem on the periphery of the Preserve, particularly on the north end.

Shoe-button Ardisia (Ardisia solanacea)
This is a mostly small understory shrub that is invading the remaining hardwood hammocks in south Florida. It appears unique among invasive plant species because it is extremely tolerant of shade, and can grow in the understory of fairly dense native hardwood hammocks. It is common, particularly in the southern part of the Preserve in the hardwood hammock. However, it is relatively easy to remove as seedlings in a small area, and we have kept it under control.

Seaside Mahoe (Hibiscus tiliaceus)
This low and spreading tree, with handsome yellow hibiscus flowers, is native to seashores of t he t ropics. It is not normally considered to be an invasive species, but it has aggressively formed a stand on the southwest corner of the Preserve.