The hydrochemical response of small southeastern Wisconsin lakes to an anthropogenic disturbance: The importance of scale and landscape position.
Allen, Paula1, 1 University of Wisconsin - Madison, Madison, Wisconsin, Madison, WI
ABSTRACT- Landscape structure, of both natural and human design, influences lake chemistry, directly and indirectly affecting aquatic community structure and function. I studied 12 small dimictic lakes over a three year period and assessed related land cover attributes at three spatial scales to answer the following questions 1) What landscape elements affect lake chemistry? 2) Does landscape position or scale affect a lakes response to differences in land use? Nonmetric multidimensional scaling (NMS) was used to explore the relationships between hydrochemistry and landscape attributes at watershed, catchment and riparian scales. Landscape attributes associated with reduced water quality include reduced patch size, high patch densities, and shorter distances to neighboring patches, increased landscape heterogeneity, high landscape interspersion and lake depth. Although not completely understood, anthropogenic disturbance (agriculture and urban land uses, and roads) at all landscape scales studied may contribute to a decline in water quality by contributing to the above landscape attributes. Additionally, people choose to live near deeper lakes with fewer macrophytes. Therefore urban development may preferentially occur around lakes that are higher on the landscape; depending on the scale of inquiry this may result in a disproportionate affect of roads on these lakes. Lakes, as part of the southern Wisconsin landscape, integrate the effects of geomorphology and human land use on water chemistry and hydrobiology.
Key words: landscape ecology, hydrochemistry, anthropogenic disturbance
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