A Proposed Aquatic Plant Community Biotic Index for Wisconsin Lakes

Abstract

The Aquatic Macrophyte Community Index (AMCI) is a multipurpose tool developed to assess the biological quality of aquatic plant communities in lakes. It can be used to specifically analyze aquatic plant communities or as part of a multimetric system to assess overall lake quality for regulatory, planning, management, educational, or research purposes. The components of the index are maximum depth of plant growth; percentage of the littoral zone vegetated; Simpson's diversity index; the relative frequencies of submersed, sensitive, and exotic species; and taxa number. Each parameter was scaled based on data distributions from a statewide database, and scaled values were totaled for the AMCI value. AMCI values were grouped and tested by ecoregion and lake type (natural lakes and impoundments) to define quality on a regional basis. This analysis suggested that aquatic plant communities are divided into four groups: (1) Northern Lakes and Forests lakes and impoundments, (2) North-Central Hardwood Forests lakes and impoundments, (3) Southeastern Wisconsin Till Plains lakes, and (4) Southeastern Wisconsin Till Plains impoundments, Driftless Area Lakes, and Mississippi River Backwater lakes. AMCI values decline from group 1 to group 4 and reflect general water quality and human use trends in Wisconsin. The upper quartile of AMCI values in any region are the highest quality or benchmark plant communities. The interquartile range consists of normally impacted communities for the region and the lower quartile contains severely impacted or degraded plant communities. When AMCI values were applied to case studies, the values reflected known impacts to the lakes. However, quality criteria cannot be used uncritically, especially in lakes that initially have low nutrient levels.

Environmental Factors as Predictors of Aquatic Macrophyte Richness and Composition in Wetlands of Southern Brazil

“…Nichols et al (2000) found that the vegetation responses to environmental factors are not always linear. While Jones et al (2003) did not find any relationships between nitrate and phosphorus concentrations and the diversity of aquatic plants in ponds, Rørslett (1991) and Murphy (2002) found that the highest macrophyte diversity was observed in mesotrophic or slightly eutrophic lakes.…”

Synthesis of Upper Mississippi River System submersed and emergent aquatic vegetation: past, present, and future

“…As they are non-mobile and cannot flee from rapid environmental changes (Clayton & Edwards, 2006), SAV provides a mechanism for relating anthropogenic inputs to the health of the UMRS. As a result, SAV can reflect both the long-term trends and short-term episodes within the watershed (Nichols et al, 2000) and can serve as a potential biological indicator of turbidity, nutrient enrichment, and other water quality impairments. Aquatic vegetation indices are currently being developed for the upper impounded reach of the UMRS as an indicator of system health (Langrehr & Moore, 2008).…”

Effects of pH and specific conductance confound the use of the Florida Lake Vegetation Index to identify anthropogenic eutrophication

“…Nichols et al (2000) proposed an aquatic plant community biotic index for Wisconsin lakes, and Rothrock et al (2008) proposed a plant index of biotic integrity for lacustrine wetlands in northwest Indiana, but neither of these indices was directly related to the anthropogenic loading of plant nutrients. Likewise, Beck et al (2010) discussed the development of a macrophyte-based index of biotic integrity for Minnesota lakes.…”