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SIMPSON'S DIVERSITY INDEX (SDI) <br />Simpson's Diversity Index (SDI) is one approach to quantifying biodiversity. SDI takes both the number of <br />species and the population size of each species into account. The resulting value is between o and i, with o <br />representing no diversity (all individuals in an area are the same species) and i representing maximum diversity. <br />0.98 <br />0.96 <br />0.94 <br />0.92 <br />0.9 <br />0.88 ............... ....... <br />.:. <br />0.84 <br />0.82 <br />2oi6 2017 2018 <br />DISCUSSION <br />Simpsons Diversity <br />2019 2020 2021 2022 20223 2024 <br />Since its beginning, the Carman bay management efforts have shown superior results. Invasive species continue <br />to be maintained at low rates and thru the various measurements, Native plants, diversity and overall bay plant <br />health have remain unchanged or have improved. Several new species have been recorded throughout the <br />various years and others have remained the same or have seasonal dips. The metrics used to measure the success <br />of this program have solidified that Invasive species can be managed with little to no impacts to the bay and <br />suggest a healthier plant community today than when the project began. Since 2019, invasive milfoil levels have <br />been kept below the 20% frequency of occurrence. In 2024, the mean native plant occurrence per point fell to 2.7 <br />from a typical 3.2 to 3.5 range. Although this is the first significant decrease, the overall metrics continue to point <br />to a very healthy plant community promoting excellent habitat and providing a sound aquatic ecosystem. <br />PAGE 4 <br />265 <br />