Lake Bradford Lake of exotic species or lakeshore alterations, and chemical disturbance such as introduc- Vegetation Index Results tion of excess nutrients, particulates, or herbicides from the surrounding land uses. (7-26-2018) The LVI method is performed from a boat, The Lake Vegetation Index (LVI) is a multi- and involves dividing a lake into 12 units metric index that evaluates how closely a and identifying plants in 4 of the 12 units lake’s plant community resembles one that (Figure 1). Plants are identified in the would be expected in a condition of minimal selected unit by a visual boat “drive by” and human disturbance. It is based on a rapid also via a transect approach. The resulting field assessment of aquatic and wetland data is used to calculate the LVI and is plants as indicators of various effects of evaluated according to the scoring system in human disturbance over time. Plants respond Table 1. to physical disturbances such as introduction

TABLE 1. Category names, ranges of values for LVI, and example descriptions of biological conditions typically found for that category. Aquatic life LVI Description use category Range Exceptional 79–100 Nearly every plant present is a species native to Florida, invasive taxa typically not found. About 30% of taxa present are identified as sensitive to disturbance. Healthy 43–78 About 85% of plant taxa are native to Florida; invasive taxa present. Sensitive taxa have declined to about 15%. Impaired 0–42 About 70% of plant taxa are native to Florida. Invasive taxa may represent up to 1/3 of total taxa. Less that 10% of the taxa are sensitive.

The Lake Vegetation Index score for Lake Lake Bradford. Alligator weed (Alternan- Bradford was 64, placing the lake’s vegeta- thera philoxeroides), is listed as a Category tive community in the healthy category. II Invasive Exotic that was found in the lake. Additionally, the exotic water spangles Forty four plant species were found during (Salvinia minima) and burhead sedge the survey. The native species, pond cypress (Oxycaryum cubense) were also found in the (Taxodium ascendens) was the most domi- littoral zone and floating tussocks of the nant species. Other species include red lake. maple (Acer rubrum), maidencane (Panicum hemitomon) and dahoon holly (Ilex cassine). For a complete list of plants found during the LVI survey, please see Table 2. Torpedo grass (Panicum repens) and Chinese tallow (Sapium sebiferum) both listed as Category I Invasive Exotics by the Florida Exotic Pest Control Council http://www.fleppc.org/ and are a concern in

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TABLE 2. Scientific and common names of the Ludwigia sp. primrose willow plants identified during the Lake Bradford Luziola fluitans southern watergrass LVI survey (7-26-18). Names in bold are Lycopus rubellus taperleaf water plants nonnative to Florida. horehound Scientific Name Common Name Najas guadalupensis southern Acer rubrum red maple waternymph Alternanthera alligator weed Nyssa sylvatica var. biflora swamp tupelo philoxeroides(II) Oxycaryum cubense burhead sedge Ambrosia artemisiifolia common ragweed Panicum hemitomon maidencane Boehmeria cylindrica false nettle Panicum repens(I) torpedo grass Cephalanthus occidentalis buttonbush Persicaria sp. smartweed Cyperus haspan haspan flatsedge Phyllanthus urinaria chamber bitter Cyperus lecontei Leconte's flatsedge Pontederia cordata pickerelweed Cyperus odoratus fragrant flatsedge Ptilimnium capillaceum mock bishop's weed Cyperus polystachyos many spike Sabal palmetto cabbage palm flatsedge Cyrilla racemiflora swamp titi Sagittaria latifolia broadleaf arrowhead Dichanthelium aciculare needleleaf rosette Salvinia minima water spangles grass Sapium sebiferum (I) Chinese tallow tree Echinochloa walteri coast cockspur grass Serenoa repens saw palmetto Eclipta alba (E. prostrata) false daisy Taxodium ascendens pond cypress Eleocharis sp. eleocharis Triadenum virginicum marsh st. johnswort Erechtites hieracifolia American burnweed Vitis rotundifolia muscadine Eupatorium capillifolium dogfennel Names in bold are exotic species. Fuirena breviseta saltmarsh umbrella I - Category I Invasive Exotics sedge II - Category II Invasive Exotics Hydrocotyle sp. water pennywort Hydrolea quadrivalvis waterpod For additional information about the LVI please go to the Florida Department of Envi- Ilex cassine dahoon holly ronmental Protection webpage; Ipomoea sagittata saltmarsh morning http://floridadep.gov/sites/default/files/lvi- glories primer-102411.pdf. For additional infor- Juncus repens lesser creeping rush mation about exotic Category I and II inva- Leersia hexandra southern cutgrass sive exotic plants, please go to the Florida Liquidamber styraciflua American sweetgum Exotic Pest Plant Council Ludwigia arcuata needleleaf ludwigia http://www.fleppc.org/list/list.htm

2 FIGURE 1. Lake Bradford showing unit divisions. Circled unit numbers denotes surveyed units.

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