Seasonal trends in permanent and ephemeral wetland water chemistry

Abstract

We investigated seasonal differences in pH, conductivity, and dissolved oxygen concentrations between permanent and ephemeral wetlands within the Chippewa Moraine State Recreation Area. These chemical attributes affect which organisms can live within these different habitats. We used general linear models to compare the effects of wetland type (ephemeral vs. permanent) and temporal variation on the water chemistry attributes. Specific conductivity was significantly higher in ephemeral wetlands than permanent wetlands, with no significant change over the growing season. Dissolved oxygen was significantly higher in permanent wetlands, but significantly decreased among sample periods in both wetland types. There was no significant difference in pH between permanent and ephemeral wetlands, but pH showed significant fluctuation between sample periods. Similar fluctuations were observed between the two types of wetlands over time. Ephemeral wetlands exhibited a higher specific conductivity and temperature which is likely due to their small size. pH fluctuations between sample periods may be affected by vegetation or soil conditions. The hydroperiod of a wetland seems to be an important factor affecting water chemical characteristics. Our findings provide a framework for investigating relationships between these water chemistry trends and biological communities.