Laserfiche WebLink
January 26, 2024 <br />Don Peterson <br />Page 7 of 21 <br />Reference: Water Quality Assessment of Silver View Pond, Mounds View, MN <br />There are no widely established metrics for the quality of the vegetation community in stormwater ponds, so <br />we compared the Silver View Pond macrophyte data to established vegetation metric thresholds for shallow <br />lakes to understand the general quality and diversity of the existing in -pond plant community (Table 4). <br />Species richness is an ecological measure of the number of different species found in a system. Another <br />common metric for aquatic plants is the floristics quality index (FQI). The metrics calculated for Silver View <br />Pond exceed the species richness and FQI thresholds for shallow lakes', which points to a diverse <br />community of aquatic plants in Silver Pond. Diversity of plant species is particularly good from an ecological <br />perspective as this provides different habitat and food resources for a wider range of species that depend <br />on those resources. <br />Table 4. Silver View Pond SAV metrics from early and late season surveys 2023. <br />Early Season <br />Late Season <br />Total Points Sampled <br />67 <br />66 <br />Total Littoral Points Sampled <br />66 <br />66 <br />% Littoral with Veg <br />98.5 <br />97 <br />Max depth of plant growth (ft) <br />8 <br />12 <br />Shallow Lake Species Richness <br />11 <br />Threshold <br />Species Richness <br />13 <br />13 <br />Shallow Lake Floristic Quality <br />17.8 <br />Index (FQI) Threshold <br />FQI <br />19.6 <br />19.2 <br />Simpson's Diversity Index <br />0.86 <br />0.87 <br />The frequency of occurrence is a measure of the number of a times a particular species appeared in a <br />sampling point on the grid. The taxa observed at each point and the relative frequency of occurrence for <br />each taxa are shown in Table 5. In general, no emergent taxa were observed. American white lily, <br />stonewart, and coontail were the dominant submersed taxa found. American white lily provides food <br />resources and habitat for waterfowl and is typically not removed from aquatic systems in Minnesota4. <br />Removal of the lily would likely allow for denser growth and expansion of native species like stonewart and <br />coontail, which can grow to nuisance conditions and have high frequency of occurrence in Silver View Pond <br />currently. <br />' Radomski, P., and D. Perleberg. 2012. "Application of a versatile aquatic macrophyte integrity index for <br />Minnesota lakes." Ecological Indicators 20: 252-268. <br />4 https://www.dnr.state.mn.us/aquatic_plants/floatingleaf_plants/white water Iily.html <br />Design with community in mind <br />