Approximately 1,300 of Florida's plant species (31 percent of the total) are non-natives which have become established; 10 percent of these are considered invasive.[6] The three most ecologically damaging are Brazilian pepper (Schinus terebinthifolius), which has taken over 703,500 acres (2,800 km2) in south and central Florida, and forms single-species environments; melaleuca (Melaleuca quinquenervia), which has invaded 488,800 acres (2,000 km2) - more than 12 percent of total land area in South Florida, and was spreading at an estimated 50 acres (202,300 m2) per day; and Australian pine (Casuarina spp.) which covered 372,723 acres (1,500 km2), and whose fallen needles release a chemical into the soil which inhibits the growth of native plants.[7]