The Effects of Urbanization on Local First-Order Streams: One Year Later

Kristen K. Cecala, Steven J. Price, William Ringle, and Michael E. Dorcas

Davidson College

Introduction
Results
Methods
Site
% Developed Watershed
Area Disturbed (m^2)
Minimum Distance (m)
Maximum Distance (m)
Site 7 91.88% 177,896 0 34
Site 4
84.07%
141,397 0 0
Site 9 79.27% 130,463 0 14
Site 10 77.94% 430,783 0 20
Site 6 65.31% 272,290 0 59
Site 5 64.65% 46,802 0 0
Site 2 v57.88% 228,700 0 69
Site 8 42.40% 91,867 13.7 158
Site 1 35.72% 132,475 0 31
Site 3 0.03% 50 0 1000

Table 1. Summary of urbanization within first-order stream watersheds. Note the wide variability. Click on the site number to see more detail about each location.

Discussion
Literature Cited
Anthropology Department
Davidson College Herpetology Laboratory
 

Figure 1. The effects of urbanization on first-order stream substrate. Values reflect the change in mean values before and after disturbance. Values above the x-axis reflect positive changes in response to urbanization and vice versa. Positive associations appear to exist between the proportion of watershed disturbance and the percentage detritus (N = 10, p = 0.148) and fine sediments (N = 10, p = 0.131), but not to sand (N = 10, p = 0.822).

 

 

Figure 2. The effects of urbanization on physical stream properties such as stream width and stream maximal depth. Width and depth do not appear to be associated with the proportion of disturbed watershed within the first year of urbanization (width N = 10, p = 0.735; depth N = 10, p = 0.211).

Figure 3. The effects of urbanization on water quality measurements. Stream water temperature and pH do not appear to be affected by the proportion of disturbed watershed (temperature, N = 10, p = 0.192; pH, N = 10, p = 0.649), but conductivity appears to have a positive association (N = 10, p = 0.336) and dissolved oxygen appears to have a negative correlation (N = 10, p = 0.031).

 

Questions? Email: Krcecala@davidson.edu