Sample Collection and Preparation--We collected aquatic invertebrates twice monthly from January 2004 through December 2006 in each MSMW when water was present.
Data Analysis--We characterized the aquatic invertebrate community composition, using the aforementioned taxonomically relevant groups, with both Simpson's Index and Shannon-Wiener Index diversity indices in each MSMW during each month (Ludwig and Reynolds, 1988; Krebs 1999).
Using those scaled water quality data, subsequent analyses were performed using basic general linear models to examine how water quality influenced aquatic invertebrate density and how biomass varied over temporal (i.e., year and month) and spatial (i.e., MSMW) scales.
Differences in invertebrate density and biomass did not vary among months (Wilk's [lambda] = 0.994, P = 0.299), years (Wilks' [lambda] = 0.999, P = 0.788), nor MSMWs (Wilks' k = 0.998, P = 0.260), and there was no year x MSMW interaction (Wilks' k = 0.994, P = 0.083).
Water Quality--Water quality parameters (i.e., water depth, temperature, conductivity, pH, and dissolved oxygen) varied among months (Wilks' [lambda] = 0.151, P < 0.001), among years (Wilks' [lambda] = 0.845, P < 0.001), among individual MSMWs (Wilks' [lambda] = 0.890, P < 0.001), and there were month x year (Wilks' [lambda] = 0.594, P < 0.001), month x MSMW (Wilks' [lambda] = 0.610, P < 0.001), and year x MSMW (Wilks' k = 0.875, P < 0.001) interactions.
As expected (and reported above), there were many interactions in water quality parameters among MSMWs, years, and months.
Although water quality metrics varied over time and among individual MSMWs, there were no relationships among water quality parameters related to time and invertebrate production, although water temperature and dissolved oxygen had some influence on aquatic invertebrate density and biomass.