2012 FDOT Mitigation Plan - Southwest Florida Water Management ...

APPENDIX B – PROPOSED RESTORATION TECHNIQUES
Proposed Restoration Techniques – The restoration sites must be prepared in advance of
seeding to ensure exotic vegetation (pasture grasses) are eradicated and soil is aerated. Site
preparation may begin 1-2 years prior to re-vegetating in order to ensure a weed-free substrate.
Prior to any treatments, the soil pH will be tested to ensure pH is between the optimal levels of
about 6 – 7; a slightly acidic pH value is preferred over an alkaline one. A late winter burn will
be conducted in late January to early March to reduce biomass of bahia grass and other exotic
forage species. The sites will then be treated with a 2-5% percent solution of RoundupPro or
AquaStar as soon as above-ground biomass of bahiagrass is sufficient. Application methods
will depend on size of site, the existing vegetation on the site, and the presence of wetlands
interspersed within the site or adjacent to it. Another burn may be conducted 2-4 weeks
following herbicide treatment depending on fuel continuity and loads. A second herbicide
application will be conducted in early summer. The sites may also be disked to break up bahia
rhizomes and also to expose seed remaining in soil bank. Following disking, the site may be
rolled to put any remaining weed seeds in contact with the soil, thus promoting their
germination. Finally, at least one additional application of RoundupPro or AquaStar, at a rate of
2 - 5%, will be conducted in September/early October. This sequence can be repeated for a
second year if weed species are still present on the site. The site may be harrowed with a disk
or a chain drag just prior to seeding if deemed necessary and also based on results of similar
treatments at GSW8 restoration site. Species that will be problematic if still present on the site
(pre- or post-seeding) include the following: bahia grass (Paspalum notatum), Bermudagrass
(Cyondon dactylon), natal grass (Rhynchelytrum repens), purple nutsedge (Cyperus rotundus),
cogongrass (Imperata cylindrica), tropical soda apple (Solanum viarum), smutgrass (Sporobulus
indicus). Species that initially may appear to be problematic will probably not be after 2-3 years
– these may include: dog fennel (Eupatorium spp.), common ragweed (Ambrosia artemisiifolia ),
Brazil pusley (Richardia brasiliensis), Florida pusley (Richardia scabra), hairy indigo (Indigofera
hirsuta). Seeds will be transported to the site from the Starkey and/or Green Swamp West seed
donor site, and either distributed immediately or allowed to dry for 24-hours. Modified sod
spriggers and/or the Grasslander seeder will be utilized to broadcast the seed at a rate of 40-60
seeds per square foot on to the prepared site. Both of these seed dispensers are designed to
scarify the soil slightly, dispense the seed, and then roll the seed into the soil. After restoration
is complete, continued maintenance to control undesirable vegetation will be conducted utilizing
a combination of herbicide treatments, mowing, and prescribed fire. In addition to direct
seeding, plant installation will also be utilized, either alone or in combination with seeding, to revegetate
the restoration sites. The primary focus will be to restore fine flashy fire fuels to the site
to facilitate required intensity and seasonality of burns, and also to provide competition against
weedy species that might otherwise invade. Wiregrass plugs will be ordered in advance from
the Florida Division of Forestry. Appropriate grasses, sedges, and wildflowers may also be
planted, depending on availability and site conditions. Plants will be contract-grown in advance
and planted during the rainy season. Additionally, seeds of species not represented in the seed
mix may be hand-collected and added.
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