Wednesday, November 5, 2014

Plant Immigration and Naturalization

Coconut palm at Kona Kai
Nothing exclaims "tropical paradise" more than the coconut palm. They are so common in our landscape in south Florida that they seem to be native to our region, but alas they are not. Where exactly does the coconut palm come from and how did it get here?

Historic records on the introduction of Cocos nucifera, the coconut palm, are difficult to trace since humans have been carrying this portable source of nutrition throughout the tropics for thousands of years. Coconut DNA analysis has shown that two varieties originated in Asia, one in the South Pacific and one in the Indian Ocean region. As far as when the coconut arrived in Florida, I located two articles. One recounted a tale of coconuts from a shipwreck floating up along the Palm Beach coast in the 1800s and another indicated the presence of coconuts in the Florida Keys in the mid-1800s. DNA analysis of Cocos nucifera which, combined with historic shipping records, show that the Indian Ocean variety of coconuts were brought to Africa by Portuguese sailors; this variety was then brought to the Caribbean. Either way, they have been here for over a hundred years and have made themselves right at home.

Coconut palm at Kona Kai

The coconut is one of the most useful plants for humans, especially due to its portability for travel on sea voyages. They have nutritious water and fleshy meat which is also processed into milk and oil, the oil is used for cooking and in cosmetics and soaps; building materials are obtained from the husks, leaves and trunk; the coir on the outside of the fruit has many traditional and commercial uses, also coconut husks are used culturally for decoration, and on and on. Early farming records in the Florida Keys indicate there were plantations of coconut trees, pineapples, tomatoes and other hardier vegetables. It was, and is, a valuable crop. It is also a valuable botanical teaching tool as people readily recognize and enjoy coconuts and are interested in learning about their various attributes. However, the coconut is not a native plant to Florida and has naturalized in the Florida Keys to the extent that it is now on the Keys' invasive species watch list.

Coccothrinax argentata, Silver palm, at Lighthouse Beach,
Eleuthera Bahamas
Close-up of Silver palm's silvery leaf
The coconut has become a problem locally at two popular tourist destinations, Bahia Honda State Beach and Lignumvitae Key Botanical State Park. Coconuts are washing up on the beach dunes at Bahia Honda and becoming established, potentially outcompeting the native Silver Palm, Coccothrinax argentata. Coconut palms persist in the tropical hardwood hammock at Lignumvitae Key, where they were planted early in the last century by private landowners, and their thatch and debris is inhibiting the germination of native plants. Left unchecked, coconut palms become established in the ecosystem and may alter the ecology for the remaining native plants and animals. In the photo from Lighthouse Beach on Eleuthera, Bahamas to the right, there are numerous coconut palms in the distance, their canopies popping up out of the native scrub. We are not sure what their long-term impacts will be, but state and county land managers in the Keys are not taking any chances. They are on the lookout for newly sprouting coconuts and actively removing trees, but they have their hands full with other, more invasive, species that are a bigger threat to the habitats in the Keys, so they need our help.

Coconut trimming at Kona Kai

How can we help reduce the number of coconuts in the environment? We need to ramp up our collection efforts and harvest them! I'm not kidding! If you have coconut palms on your property, you likely have someone come cut down the coconuts so they don't endanger pedestrians and property when they fall. Keep up the good work!
These delicious fruits also provide many cottage-industry product ideas to local artisans: homemade Keys coconut soaps, body scrubs, lotions and hair oils; locally sourced coconut milk for cocktails and coconut pies - who says we can only be famous for Key Lime pie?; cooking oil for fried lionfish fritters - another invasive species that we are hunting and eating! We need to jump on the locavore band wagon and start providing tourists with locally grown food and locally sourced ingredients so their experience in the Keys is even more memorable. 
Raw coconuts and two clever uses for cleaned/dried coconuts 
By actually using this valuable resource, we can help remove the coconuts from the environment, limiting their ability to disperse and grow in the wild. There are so many coconut palms throughout the state that it is inconceivable to think about removing them all so we need to come up with other means of control. I'm going to start by cutting the coconuts down from the tree in my front yard. I can't think of a tastier way to control invasive plants!

For more information on the genetic research done to decode the origins of coconuts, follow this link: 

Thanks for reading!
Emily B. Magnaghi
Associate Director