IMPACTS OF URBAN LANDUSE ON MACROINVERTEBRATE COMMUNITIES IN SOUTHEASTERN WISCONSIN STREAMS¹

Abstract

Macroinvertebrates were used to assess the impact of urbanization on stream quality across a gradient of watershed imperviousness in 43 southeastern Wisconsin streams. The percentage of watershed connected imperviousness was chosen as the urbanization indicator to examine impact of urban land uses on macroinvertebrate communities. Most urban land uses were negatively correlated with the Shannon diversity index, percent of pollution intolerant Ephemeroptera, Plecoptera, and Trichoptera individuals, and generic richness. Nonurban land uses were positively correlated with these same metrics. The Hilsenhoff biotic index indicated that stream quality declined with increased urbanization. Functional feeding group metrics varied across a gradient of urbanization, suggesting changes in stream quality. Proportions of collectors and gatherers increased, while proportions of filterers, scrapers, and shredders decreased with increased watershed imperviousness. This study demonstrated that urbanization severely degraded stream macroinvertebrate communities, hence stream quality. Good stream quality existed where imperviousness was less than 8 percent, but less favorable assessments were inevitable where imperviousness exceeded 12 to 20 percent. Levels of imperviousness between 8 and 12 percent represented a threshold where minor increases in urbanization were associated with sharp declines in stream quality. (KEY TERMS: aquatic ecosystems; nonpoint source pollution; urban landuse; imperviousness; urban runoff; stream quality; macroinvertebrates; biotic index; functional feeding groups.)

Variations in benthic macroinvertebratefauna as indicator of land use in the Ken River, central India

“…However, the faunal richness declines marginally from semi-natural (15 taxa) to urban land use (14 taxa), but declines notably in agricultural land use (12 taxa) indicating the impact of the landuse. The invertebrate density is known to be higher in agricultural streams than forest streams (Lenat 1984;Harding & Winterbourn 1995;Mishra & Nautiyal 2011) and least in the urban land use streams (Hilsenhoff 1988;Novak & Bode 1992;Paul & Meyer 2001;Walsh et al 2001;Stepenuck et al 2002;Wang & Kanehl 2003;Fleituch 2003;Mishra & Nautiyal 2011, 2013Nautiyal & Mishra 2012) as observed in the present study also. Longitudinally, benthic macroinvertebrate density usually increases from headwater to mouth (Nautiyal 1997;Kownacki et al 2000;Younes-Barailla et al 2005;Milesi et al 2009), but has been observed to decrease in the plateau rivers of Bundelkhand region (Mishra & Nautiyal 2012;Nautiyal & Mishra 2012).…”

Effects of anthropogenic impacts on benthic macroinvertebrates assemblages in subtropical mountain streams

“…In addition, richness, diversity and evenness of collector-gatherers differed among undegraded and degraded sites. This result was in accordance with other works (Rawer-Jost et al, 2000;Stepenuck et al, 2002;Compin & Céréghino, 2007), showing the utility of the structure of functional feeding groups of macroinvertebrates as indicators of anthropogenic impacts. Native forested sites having good ecological conditions supported more diversity and richness of collector-gatherers, whereas sites degraded by anthropogenic impacts showed a significant decrease in these parameters.…”

Large‐scale relationships between basin and riparian land cover and the ecological status of European rivers

“…The impacts of urbanisation are mainly related to the direct effects of point sources of pollution. However, many other pressures are generated by urban areas, such as canalization, untreated storm-water and altered hydrological regimes (Cormier et al, 2000), and these cause both hydro-morphological and biological impacts (Paul & Meyer, 2001;Stepenuck, Crunkilton & Wang, 2002;Roy et al, 2003;Wang & Kanehl, 2003). When comparing the impacts of different forms of land cover, some authors found agriculture to be the most damaging activity, while others found the strongest negative correlations with urban areas.…”