Effects of Water Level Fluctuation and Nutrient Levels On Wetland Plant Biological Integrity. II.

Minnesota Pollution Control Agency has developed plant and macro invertebrate indices of biological integrity (IBI) to assess wetland ecological health since 1995. From the same year, six wetlands in southern Minnesota have been monitored by water, plant and macro invertebrate samplings in summers. Plant IBI scores have been assessed for five years for each wetland so far. Water samples were collected for physical and chemical property analytes: water temperature, turbidity, pH, conductivity, chloride, Kjeldahl nitrogen, total phosphorus, and dissolved oxygen. Water sampling times have been increased to monthly since 2008; automatic loggers have also been deployed to record hourly water levels. Results from statistical analyses showed very high significant levels of correlations among plant, water quality, and water level. It is concluded that water characteristics have significant effects on plant biological integrity and water level fluctuation has potential impacts on wetland plants by significantly correlating to water chemistry.