Document Type


Publication Date



Water quality--Minnesota; Watershed ecology


ABSTRACT-Surface water quality in southeastern Minnesota's driftless area exhibits subregional and local spatial patterns which are highly correlated with subsurface geology and land-use practices. Some variables appear to respond on subregional or watershed scales. Nitrate, specific conductance, alkalinity, and surface water atrazine concentrations were lower in streams originating from the Prairie Du Chien or Jordan sandstone ~quifers of easte:n Fillmore and Houston Counties than those originating from the Galena limestone aquifer m west-central Fillmore County. In addition, the numbers of pollution intolerant and functionally specialized invertebrates in the benthic community were higher in the eastern streams. Gross primary production on tile substrates, transported organic matter, and atrazine concentrations were highest in an agricultural watershed and lowest in a forested watershed. Other variables are more responsive to local influences such as riparian land-use. Substrate median particle size, macrophyte composition on riffies, diversity of benthic invertebrates, and number of invertebrate predators were highest on riffies adjacent to forested riparian zones. Stream temperature and turbidity were higher at riffie sites adjacent to open agricultural riparian zones. Our resul~s demonstrate spatial patterns in southeastern Minnesota water quality which are strongly correlated with subsurface geology and land-use practices. These patterns exist on different spatial scales (i.e., local, wate_rs~ed, ~ubregio~al) within the driftless area ecoregion. Effective monitoring and management of water quality m this ecoreg1on must consider a finer spatial scale than that suggested by the aquatic ecoregion approach.

First Page


Last Page


Primo Type


Included in

Geology Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.