lab 1 interreach variability
Interreach variability and correlation analyses between biotic and abiotic factors of the Old Chelsea stream
BIO2129 Section
Demonstrators:
October 1, 2014
Department of Biology
Hypotheses
Water quality parameters such as pH, dissolved oxygen, seston, water temperature etc. are important variables in the abundance and diversity of benthic macroinvertebrates of the Old Chelsea stream. Therefore, it can be hypothesized that pH and dissolved oxygen have a direct correlation on biotic factors within the stream. Furthermore, due to the surface water velocity variations of the stream, it is hypothesized that water pH and dissolved oxygen interreach variability is statistically significant.
Results
Note that for figures 1 and 2, the black bars and white bars represent site 1 and site 2 respectively. Furthermore, the horizontal axes represent the reach in this order: reach 5vs reach 7, reach 5 vs reach 1, reach 7 vs reach 1.
Figure 1. Bar graph showing the mean (+ standard error) of pH vs reach for both site 1 and site 2.
Figure 2. Bar graph showing the mean (+ standard error) of dissolved oxygen vs reach for both site 1 and site 2.
Table 1. t-tests comparing reaches 1+5, 5 +7, and 7+1 for pH and dissolved oxygen within site 2. The means of 6 samples are demonstrated. The interreach variability is demonstrated by the calculated t column and is followed by a statistical conclusion.
Site 2
Abiotic factors Reach # Mean Standard deviation Reach comparison Calculated t Statistical conclusion pH 1 8.206666667 0.015275252 1 v. 5 -2.218800785 Fail to reject 5 8.19 0.017320508 5 v. 7 -1.25 Fail to reject 7 8.216666667 0.011547005 7 v. 1 0.904534034 Fail to reject
Dissolved oxygen 1 9.863333333 9.863333333 1 v. 5 -5.350053918 Reject 5 9.656666667 0.065064071 5 v. 7 -2.514432028 Fail to reject 7 9.86 0.01 7 v. 1 -0.045454545 Fail to reject a_ α = 0.05 b_ Critical t = 2.776 c_ Degrees of freedom = 4
Figure 3. Significant
BIO2129 Section
Demonstrators:
October 1, 2014
Department of Biology
Hypotheses
Water quality parameters such as pH, dissolved oxygen, seston, water temperature etc. are important variables in the abundance and diversity of benthic macroinvertebrates of the Old Chelsea stream. Therefore, it can be hypothesized that pH and dissolved oxygen have a direct correlation on biotic factors within the stream. Furthermore, due to the surface water velocity variations of the stream, it is hypothesized that water pH and dissolved oxygen interreach variability is statistically significant.
Results
Note that for figures 1 and 2, the black bars and white bars represent site 1 and site 2 respectively. Furthermore, the horizontal axes represent the reach in this order: reach 5vs reach 7, reach 5 vs reach 1, reach 7 vs reach 1.
Figure 1. Bar graph showing the mean (+ standard error) of pH vs reach for both site 1 and site 2.
Figure 2. Bar graph showing the mean (+ standard error) of dissolved oxygen vs reach for both site 1 and site 2.
Table 1. t-tests comparing reaches 1+5, 5 +7, and 7+1 for pH and dissolved oxygen within site 2. The means of 6 samples are demonstrated. The interreach variability is demonstrated by the calculated t column and is followed by a statistical conclusion.
Site 2
Abiotic factors Reach # Mean Standard deviation Reach comparison Calculated t Statistical conclusion pH 1 8.206666667 0.015275252 1 v. 5 -2.218800785 Fail to reject 5 8.19 0.017320508 5 v. 7 -1.25 Fail to reject 7 8.216666667 0.011547005 7 v. 1 0.904534034 Fail to reject
Dissolved oxygen 1 9.863333333 9.863333333 1 v. 5 -5.350053918 Reject 5 9.656666667 0.065064071 5 v. 7 -2.514432028 Fail to reject 7 9.86 0.01 7 v. 1 -0.045454545 Fail to reject a_ α = 0.05 b_ Critical t = 2.776 c_ Degrees of freedom = 4
Figure 3. Significant
References: ngelier, E. 2003. Ecology of streams and rivers. pp. 27-99. Science Publishers, EnfeildGiller, P.S., Malmqvist,B. 1998. The biology of streams and rivers. pp. 30-98. Oxford University Press, New York Michaud, J ts = (8.19 - 8.206667) / [(0.0173212 + 0.0152752) / 3]½ ts = 0.904534 r = [1116.87 – (160.58 x 139) / 20] [(1289.869– 25785.94 / 20) x (987 – 19321 / 20)]½r = 0.267408721