UC Davis Department of Plant Sciences


Aquatic Macroinvertebrates




Table 3 below reports key aquatic macroinvertebrate metrics. A high value of the percent of the macroinvertebrate community tolerant of pollution (% Tolerant) is an indicator of poor riparian health. Conversely, high values of (i) the percent of the macroinvertebrate community not tolerant of pollution (% Intolerant), (ii) of the Shannon Diversity Index (D.I.), and (iii) of the number of families detected (No. Families) are indicators of good riparian health. Collectively, the data indicates high water quality and in-stream habitat conditions at all three creeks throughout the course of this study.

% Tolerant was zero in 86 % of samples collected. The highest % Tolerant value was 0.6 %, at upstream station PC13. At all three creeks, the Shannon Diversity Index, No. Families, and % Intolerant varied from year to year at each station, but showed no correlation with treatment effect. Furthermore, both upstream (reference) and midstream and downstream (treatment) locations exhibited similar levels of annual variation, which indicates the variation detected from site to site and year to year reflects inherent site habitat quality, and annual variation in the timing of insect hatch and community development, rather than conifer removal effects. The lack of response is not surprising given that the factors that would cause changes in aquatic macroinvertebrate communities (temperature, stream chemistry, turbidity), were unaffected by conifer removal.











Table 3: Aquatic macroinvertebrate metrics for Pine, Bogard, and Bailey Creek samples collected June-July 2003 -04, 2007-08, 2010.  



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