 Alien Invasion
There’s a place for every tree in this worldHowever, your backyard is not necessarily a good place for a number of them. Florida is the unwitting host to a number of non-native trees and plants. Some of them have naturalized harmoniously into our environment; others earn infamy as invasive or alien species that compete with and sometimes, displace native trees for space and resources. These alien legions have the potential to substantially alter our ecosystem, including aquatic systems. How did they get here?
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The Australian Pine is thought to have been a stowaway on boats into south Florida in the late 1800s.
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Brazilian Pepper and Chinaberry were introduced in the mid-1800s as an ornamental.
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Melaleuca, originally imported as an ornamental tree at the turn of the 20th century, was purposely cultivated throughout the Everglades in the 1930s as an ill-conceived forestation project.
Certain species are deemed so aggressive as to have been banned from sale, propagation or planting; see Sarasota County Ordinances, Article XIX, §54-621, which bans and encourages the removal of Melaleuca, Australian Pine, Brazilian Pepper, Carrotwood and Chinese Tallow. In general, these trees lack structural distinctions essential to our environment, such as resiliency and flexibility in high winds, tropical storms and hurricanes.
In addition, invasive non-natives rob our natural wildlife of refuge, forage, breeding and nesting grounds.
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Brazilian Pepper has routed mangrove birds from their natural rookeries and disrupted the nesting habitat of the gopher tortoise.
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Chinese Tallow commonly displaces native vegetation, and ultimately establishes itself as a monoculture.
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Along waterways, estuaries and coastlines, decay from its persistent leaf drop encourages algal blooms.
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Small mammal population densities are much lower where Melaleuca forests thrive.
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The Australian Pine is an allelopathic species. It releases toxins through its root system and abundant leaf litter that quickly render an area uninhabitable for other trees and vegetation (although, Carrotwood seems oddly immune).
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Along our coastline, Australian Pine stands also encourage beach erosion, with dense but shallow roots that prevent endangered sea turtles and American crocodiles from excavating suitable nesting cavities.
Beyond the banned invasives, the Florida Exotic Pest Plant Council has designated other non-natives for their negative influence, adverse impact or unsuitability for our environment. Refer to Tree Portfolio for a comprehensive list of both Category I (alter ecosystem processes) and Category II (rapidly proliferating) invasives. |