Strategic Plan for Exotic Removal North Thousand Islands Cocoa Beach, Florida

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1 Strategic Plan for Exotic Removal North Thousand Islands Cocoa Beach, Florida Background: In 1986, concerned about the potential development of the Thousand Islands, the City of Cocoa Beach approached Brevard County and the State of Florida for assistance in acquiring the North Thousand Islands property. In 1988, the property was purchased for $3,230,950 by a consortium of the City of Cocoa Beach, Brevard County and the State of Florida. In 1991, the property was leased to the City of Cocoa Beach (Lease #3923) to manage for the conservation and protection of natural and historic resources and for resource based public outdoor recreation. As required by the terms of the lease, the City developed and submitted a management plan for the North Thousand Islands in The 1994 management plan was updated by the City s Land Management Committee, endorsed by the City Commission and approved by the Florida Department of Environmental Protection in Consistent with the terms of the lease, both the 1994 and 2012 management plans include language concerning the management or control of exotic species. The 2012 management plan includes a provision for the development of a strategic plan for the removal or control of exotic, invasive or nuisance species and for the restoration of natural plant communities. Current Conditions: Current extent and composition of exotic vegetation in the North Thousand Islands is as noted in the 2012 Management Plan for the North Thousand Islands: The uplands within the North Thousand Islands are heavily infested with non-native plants. The most problematic species are Brazilian pepper and Australian pine. These two species account for the vast majority of the acreage of invasive non-native vegetation. While most of the Australian pine is limited to the larger spoil islands (~20 acres), Brazilian pepper is mixed with Australian pine on the larger spoil islands as well as smaller spoil islands, and on the higher portions of ditch banks associated with ditches created for mosquito control. Melaleuca is found in a few discrete upland areas estimated to total less than 5 acres. The management plan also includes a table listing exotic plant species found in the North Thousand Islands. Most of the additional exotic species are found in association with Australian pine and Brazilian pepper.

2 Scientific Name Common Name EPPC Category Govt. List Degree of Infestation Cassia javanica Pink Shower Moderate Casuarina equisetifolia Australian Pine 1 P High Casuarina glauca Suckering Australian Pine 1 P High Catharanthus roseus Madagascar Periwinkle Moderate Cupaniospis anacardioides Carrotwood 1 N Moderate Lantana camara Lantana 1 Moderate Melaleuca quinquenervia Melaleuca or Punk Tree 1 N, P Moderate Momordica charantia Balsam Apple Moderate Schefflera actinophylla Australian Umbrella Tree or Moderate Octopus Tree 1 Schinus terebenthifolius Brazilian Pepper 1 N, P High Washingtonia robusta Washington Fan Palm Low Yucca aloifolia Spanish Bayonet or Aloe Yucca Low The following graphic shows the general location and extent of the primary non-native plants (Brazilian pepper and Australian pine) in the North Thousand Islands. The area circled in red denotes an island with dense Australian pine and Brazilian pepper that is scheduled to be used as a spoil site in an upcoming channel maintenance project. Total acreage of exotic infestation is estimated at 35 acres.

3 Strategies: Common methods of exotic plant control include: 1) Clear and grub/pile and burn: trees removed with root systems, then piled and burned 2) Clear and grub/chip: trees removed with root systems, then chipped 3) Cut stump/pile and burn or chip: cut tree, treat stump with herbicide, pile and burn or chip 4) Basal bark: herbicide applied to base of trunk, tree left standing 5) Foliar herbicide: herbicide applied to foliage 6) Mulching in place: grinding with specialized equipment that grinds the tree down to soil surface (e.g. Brontosaurus )

4 Clearing and grubbing involves the use of large equipment which would be transported to the islands by barge. The clear and grub/pile and burn strategy was used in the South Thousand Islands on North and West Crawford islands. Similarly, mulching in place involves large equipment transported by barge. Due to restricted access on several of the islands (shallow water, mangrove shoreline) use of these strategies will only be an option on a limited number of islands. Because of the need to transport large equipment by barge to work sites the clearing and grub and mulching in place methods are generally more expensive than other methods but are more effective at preventing regrowth from stumps and roots. The cut stump method was used in the South Thousand Islands on South Crawford island. Australian pine, Brazilian pepper and other exotics were cut down and herbicide was applied to the stumps. The cut material was placed in piles and burned. Basal bark treatment was used throughout the Thousand Islands Conservation Area (South Thousand Islands) as an initial treatment of Brazilian pepper and other exotic plants. Following the strategic plan for exotic plant control developed for the Thousand Islands Conservation Area, most Australian pines were not treated as part of this initial effort however basal bark treatment is an effective method for controlling Australian pine. Foliar treatment has been primarily used for control of sprouting or plants at the small shrub scale or regrowth rather than treating mature plants. Treating large trees with a foliar spray may result in drift of herbicide which could affect non-target plants. Clear and grub or cut stump with burning or chipping is the preferred method for treating areas predominantly vegetated by Australian pine. Cut stump or basal bark treatment is commonly used to treat areas dominated by Brazilian pepper. Follow-up Treatment and Planting: Once the exotic plants are treated, it is anticipated that regular herbicide retreatment will be required in most areas as there is an abundant seed bank for Australian pine, Brazilian pepper and other exotics present in the soil. Although it is anticipated that native species will thrive once the exotics are removed, exotics will be present in the long term. As the coverage of native species increases, this will inhibit the propagation of exotics. Some of the areas where exotic, invasive or undesirable plants are treated or removed will be revegetated with appropriate native species such as mangrove, sabal palm, palmetto, seagrape, oak, cedar, wax myrtle, Florida privet and similar species. In other areas, natural recruitment will be the primary method of habitat restoration following the removal of exotic species. In the Thousand Islands Conservation Area (South Thousand Islands) planted sites were located adjacent to residential areas and were planted for aesthetic purposes as well as habitat restoration/creation. Decisions on where planting is necessary or appropriate will be made based on an assessment of individual sites.

5 Removal and Restoration Schedule: A phased removal of Australian pine, Brazilian pepper and other exotics is proposed. As an initial step, groupings of areas with exotic vegetation have been developed. Exotic plants within individual groups will be treated at the same time while treatment of the various groups will be phased over time. While the precise timing of the various phases will depend on the availability of funding for these projects, similar to the strategic plan for the Thousand Islands Conservation Area implementation of each phase will be separated by a minimum of a three year period. This will allow for revegetation (either by planting or natural recruitment) of cleared areas and restoration of the aesthetics of the area. The following graphic shows the groups and phases for treatment: Phase 1 includes three islands south of the 200 channel and adjacent to residential areas. As previously noted, the island circled in red contains a spoil site scheduled to be used in an upcoming channel maintenance project. It is our understanding that the permit issued for this project requires the removal of exotic species from this island. Perhaps the two adjacent islands included in this phase could be included as part of the spoil site project. Either clear and grub or cut stump with chipping or burning is the recommended treatment method for these islands as

6 they are predominantly covered by Australian pine. Revegetation using appropriate native species is recommended for the islands treated in this phase. Phase 2 includes areas along and adjacent to Minuteman Causeway south to the 500 channel. Recently the City of Cocoa Beach and Keep Brevard Beautiful undertook a project to treat Brazilian pepper along Minuteman Causeway however some Brazilian pepper and other exotic vegetation remain in this area. Noting that the areas dominated by Australian pine are small (generally an acre or less) and access is difficult the recommended treatment is cut stump and burn. The areas dominated by Brazilian pepper are accessible from Minuteman Causeway or Roosevelt School. Cut stump and chip is recommended in these areas. Natural recruitment rather than revegetation is recommended in Phase 2. Phase 3 includes a series of islands along the 300 channel. Basal bark treatment is recommended for the areas dominated by Brazilian pepper, Natural recruitment rather than revegetation is recommended in these areas. The two areas dominated by Australian pine are relatively small but access is limited. Cut stump and burning is recommended. Natural recruitment is recommended at the western location; revegetation is recommended at the eastern site. Phase 4 includes a 15 acre island located along the 100 channel adjacent to a residential area. The area is predominantly vegetated by Australian pine and access is available at a number of locations. Clear and grub or cut stump followed by chip or burn is recommended for this site. Revegetation is recommended for this site.