Invasive Plants in Florida
Webster's Dictionary defines invasive as: tending to infringe or spread; and over the years Floridian's have continued to suffer from an invasion of non-native plants that threaten the pristine beauty of our natural places. If plants were here before Columbus arrived they are considered native. Since a native plant doesn't usually take over its home range, it can exist in harmony with many other plants. Without human intervention, these invasives will continue to push out our native vegetation, leaving us in dire straits financially to eradicate or try and manage these plants. With over 4,000 plant species in Florida, roughly 1,000 are non-native - sometimes called exotics. The State of Florida has one of the most severe exotic species problems in the country. These non-native plants are defined as having arrived following the occupation by European man, since roughly 1513. But to be fair, not all non-native plants are problematic, just look at both the citrus trees as well as our tomatoes.
Florida's Exotic Pest Plant Council, FLEPPC, offers their breakdown and definitions as: Exotics are a species introduced to Florida, whether purposefully or accidentally, from a natural range outside of Florida. Native are a species whose natural range included Florida at the time of the European contact, roughly 1500 AD. Naturalized exotic is an exotic that sustains itself outside cultivation, if it is still exotic - it has not become native. And, lastly, Invasive exotics, are an exotic that not only has naturalized but is expanding on its own in Florida native plant communities. These wild exotic plants have been divided into two classifications, Category 1 and Category 11. Those in the Category 1 consist of 67 exotic plants that are causing ecological damage to native plant communities; while those in Category 11 consist of 71 plants that are spreading and increasing in range, but have yet to cause actual ecological damage. Let's look at some of the major culprits; all in the top 10 of destructive invasive plants listing, as well as listed in the Category 1 by the Florida Exotic Pest Plan Council: Australian Pine, Brazilian Pepper, Java Plum, Melaleuca and the Old World Climbing Fern just to name a few.
Australian Pine, originally from Australia - but not an actual pine tree - was
intentionally planted on purpose, back in the 1880s, along the shorelines, as a landscape tree, while also providing windbreaks along both property lines and canals; however, its shallow roots are easily uprooted in hurricanes and tropical storms, and prone to toppling while creating massive amounts of beach erosion during these catastrophic events. It has been classified as a Category 1 pest by the Florida Exotic Pest Plan Council and is illegal to plant in Florida. Due to its denseness, it crowds out the native plants while also producing allelopathic compounds - as other exotic plants do - which prevents other plants from growing. These trees were a major menace following Hurricane Andrew in 1992, when they toppled into the canals which then became clogged and led to extensive flooding.
Brazilian Pepper, also known as "Florida Holly", was introduced to Florida in the late 1890s from South America, as an ornamental plant, due to its small, red spherical cluster of berries. One of the most aggressive and widespread invasive plants, it is hard to control, because of both its hardiness, when its trunk is cut it produces basal shoots, coupled with its abundance of seeds that are scattered by ants and birds alike. Since it can grow in both dry and wet conditions it quickly chokes out most indigenous trees and plants. Here in Florida, it is legally prohibited from sale, planting or transport, having been classified as a Category 1 pest by the Florida Exotic Pest Plant Council. The sap from the plant can also cause skin reactions, to those with sensitive skin and many have experienced watering eyes and/or breathing problems if ingested. The smoke from burning the wood is also toxic.
Java Plum, syzygium cumini, is native to the Indo-Malayan region but has been found disturbing the hammocks of central and southern Florida. First introduced to Florida in 1911 by the Unites States Department of Agriculture, it is a fairly fast growing species, and generally described as a perennial tree that can live for more than a century. The wood is strong and water resistant, and because of the denseness in their canopies, it stunts the growth, or life actually, of the young native trees in our hammocks, wet pine lands as well as well-drained upland areas too.
Melaleuca, ironically and purposely introduced by plane, to Florida, from Australia, in order to dry up the swampy Everglades, to make it more suitable for human use. These plants covered half a million acres and are now being removed at a huge expense. It has now become a serious problem, since the plants are highly flammable and spread so aggressively; quadrupling in Southwest Florida over the past decade. It is prohibited by the Department of Environmental Protection and is also listed as a noxious weed.
Old World Climbing Fern, which is native to Australia, is a serious invader of swamps, glades and hammocks, while literally smothering anything in its path. The dense growth from the plant has also been known to be a fire hazard, enabling small ground fires to reach into tree canopies where it kills growing branches. It should be noted that invasive exotics, such as this plant, can change the effects of physical processes in plant communities. This climbing fern shades out the native vegetation of acres of plants, and while 'climbing' can quickly stretch upward into lengths up to 100 feet long. Our research indicated that this fern was first found naturalized in the United States in 1965.
The ABCs of the Florida Landscape is written by freelance writer Maureen Sullivan-Hartung who has resided in Naples for 30 years now and who loves learning about all aspects of the local flora and fauna. Another passion of hers is local history and she authored a book in November 2010, titled, Hidden History of Everglades City & Points Nearby, published by The History Press. Check her website for the book's availability or additional information about the author at >www.maureenwrites.com.