quantitative analyses of periphyton biomass and ... - SUNY Oneonta

Stream Characterization
RESULTS
The formula used to calculate the trophic level index for each stream in
order to characterize each as agricultural, forested, or urban is shown in Figure
7. The data in Table 1 used in the formula were number of agricultural and
forested acres and yearly average concentrations of T-P0 4 and N0 3 .
# agricultural acres yearly ave of yearly ave of
+ +
# forested acres rr· P04] [NOs]
TROPHIC
LEVEL
AGRICULTURAL STREAMS: STREAM # INDEX
17 3.94
16 2.88
20 2.62
6 2.09
FORESTED STREAMS: 15 1.23
5 1.02
9 0.97
4 0.91
URBAN STREAM: 2 1.18
Figure 7. The general trophic condition of each stream basin was calculated
by using the above formula. In this way, the stream basins were characterized
as agricultural or forested by comparing the individual stream indices. Higher
trophic values indicate more agricultural acres than forested acres in the
stream basin and higher yearly average total phosphorus (T-P0 4 ) and nitrate
(N0 3 ) concentrations.. Stream 2 was characterized as urban because the last
type of environment the stream flows through before reaching the lake is
residential which is highly influential to water quality of Otsego Lake.
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