National Invasive Species Awareness Week is Monday, February 25th through Sunday, March 3rd. And here in the Florida Keys, we are no stranger to opportunistic invaders trying to takeover habitats that aren’t rightfully theirs.
An invasive plant is one that is introduced to an area and forms self-sustaining, expanding populations within plant habitats they are not associated with and has long-lasting ecological impacts. Invasive plants, displace native plants (along with the birds, insects, pollinators, and other wildlife that are associated with those habitats), which often include threaten and endangered species. In fact, the Florida Keys is home to about 70 State threatened and endangered plants. From 1997 to 2014 over $129 million was spent by the State of Florida to control invasive plants in upland habitats alone (habitats at higher elevation than the surrounding vegetation at sea level). Additionally, invasive species rank second, only behind habitat destruction, as a major threat to biodiversity or the variety of species in any given habitat. Thus, the more rich and diverse a habitat, the more wildlife or animals it can sustain.
WHY IT MATTERS
Invasive species often form dense monocultures. For instance, Beach Naupaka (Scaevola taccada) is a fast growing shrub that escaped cultivation in the 1980’s from Lee County. Today it can be seen all throughout the Keys invading beach dunes, mangrove and coastal hammocks and it is often found in residential landscapes. Beach Naupaka will take over a dune habitat and displace important dune plants such as Sea Oats (which play a critical role against erosion), Sea Lavender and Inkberry (a threatened native Scaevola species). It is also called half-flower because the petals form a semi-circle, so it looks like half of the flower is missing. It produces a lot of white-clustered fruit often within the first year of growth and can grow to 16 feet in height. The seeds are spread by birds and can float for up to a year till reaching a suitable destination.
Brazilian Pepper (Schinus terebinthifolius) was first imported as an ornamental plant in the 1840’s and has invaded a wide-variety of habitats including roadsides, hardwood hammocks and mangrove forests. Its dense thickets of woody stems often completely shade out native vegetation and it even produces certain allelopathic chemicals which suppress the growth of other plants. Its seeds are spread by wildlife and its fruiting time correlates to when many migratory birds are traveling through Florida. It is estimated Brazilian Pepper covers over 700,000 acres in central and south Florida.
Snake Plant, Sanseveria sp. (a.k.a. Bowstring hemp, mother-in-laws tongue) is often sold at nurseries. These plants grow by creeping, underground rhizomes and can also reproduce by seed. Sanseveria often form dense clusters and disrupt underground habitats. It can also re-grow from vegetative stems improperly disposed of and caution should be taken when removing the plant for that reason.
WHAT CAN WE DO?
A good place to start is with your own landscape. Learn to recognize and identify the invasive plants in your community. Removing these plants from your property can help eliminate a source of further spread. Care should be taken when removing these plants though and proper disposal techniques followed. Material should be double-bagged to prevent spread during transport. Once placed into garbage bags, they should be placed into waste receptacles so they are transported to the proper facility. If this landscape material is put out with other yard waste, it could have further impacts on our community and spread either by seed dispersal or vegetative stems, since yard waste is taken to other parts of the state to be composted. Additionally, if tree stumps are not removed, they may need to be treated with an appropriate herbicide to prevent regrowth. Always follow label directions when applying pesticides. When removing any trees, contact Monroe County for a free removal permit. This allows the County to ensure it is an invasive species and not a native plant that is being removed. Removing plants when they are small saplings will be easier and less intensive. Continue to monitor the area and pull up any re-growth.
Educate your neighbors. As a tropical environment, we have no dormant season, and plants grow year-round. So small, seemingly insignificant plants can quickly spread out of control. Help make a positive impact in the community and educate others about invasive plants.
Download the smartphone app IveGot1 for identifying and reporting invasive plants and animals in Florida. IveGot1 brings EDDMapS (Early Detection & Distribution Mapping System) to your smartphone. EDDMapS is a web-based mapping system for documenting invasive species. All data is reviewed by state verifiers and is used by researchers, land managers, educators, state and national parks and conservationists.
There are several organizations monitoring, educating and helping to remove invasive plants from our native habitats, and all have a similar goal, to reduce the invasion of exotic, invasive plants. Locally, there is the Florida Keys Invasive Exotic Task Force https://www.floridainvasives.org/Keys/ that was established in 1996 and they work with the Florida Exotic Pest Plant Council that update the invasive species list bi-annually https://www.fleppc.org/index.cfm. Additionally, UF/IFAS Assessments evaluates the invasion risk of the non-native species in our State https://assessment.ifas.ufl.edu/.
Finally, replant these areas with native or non-invasive plants. Below is a condensed list of some of the invasive plants you will find in the Keys and replacement options.
Enloe, S.F. and K.A. Langeland. February 1998. Revised August 2018. “Help protect Florida’s Natural Areas from Non-Native Invasive Plants.” Circular1204. Gainesville: University of Florida Institute of Food and Agricultural Sciences. http://edis.ifas.ufl.edu/pdffiles/AG/AG10800.pdf
Knox, G.W., S.B. Wilson, Z. Deng, R. Freyre. September 2013. Revised August 2018. “Alternatives to Invasive Plants Commonly Found in South Florida Landscapes.” ENH1222. Gainesville: University of Florida Institute of Food and Agricultural Sciences. http://edis.ifas.ufl.edu/pdffiles/EP/EP46700.pdf
Langeland, K.A., K. Craddock Burks. 1998. “Identification & Biology of Non-Native Plants in Florida’s Natural Areas.” Gainesville: University of Florida Institute of Food and Agricultural Sciences.
|Invasive Plant (Common Name)||Invasive Plant (Botanical Name)||Non-invasive alternative|
|Australian Pine||Casuarina equisetifolia||Inkwood (Exothea paniculata), Japanese Yew (Podocarpus macrophyllus)|
|Beach Naupaka||Scaevola taccada||Inkberry (Scaevola plumieri), Bay Cedar (Suriana maritima), Yellow necklacepod (Sophora tomentosa sp. truncata)|
|Snake plant||Sansevieria sp.||Spider Lily (Hymenocallis latifolia), Croton (Codiaeum variegatum)|
|Brazilian Pepper||Schinus terebinthifolius||
|Lead Tree||Leucaena leucocephala||Wild Tamarind (Lysiloma latisiliquum)|
|Lantana, shrub verbena||Lantana camera||