Koontz, J., D.G. Huggins, C.C. Freeman, D.S. Baker - Central Plains ...

TOC mg/L
TOC mg/L
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a b
AB EM MIX UB
Wetland Type
LIMMIX
LIMAB
c
LITUB
LITMIX
LITEM
LIMUB
Wetland Class + Type
RVUB
RVEM
PUB
PMIX
PEM
PAB
TOC mg/L
Figure 25. Error bar charts of total organic carbon concentration among (a) wetland class, (b)
type, and (c) combined classifications. Error bars are one standard error.
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Nitrogen
Ammonia (NH3) concentrations were similar among all wetlands, regardless of population
(reference vs. random), ecoregion, wetland class, or CPCB type. However, nitrate was found to
be significantly different (Kruskal-Wallace, p = 0.004) between the reference and random
wetland groups, with reference wetlands having higher nitrate (mean = 0.05 mg/L) in the 2005
samples than the 2008 and 2009 samples (men = 0.03 mg/L). Nitrite contributed the least
significant fraction of the Nitrate+Nitrite measure, which might be expected since it is the first
step in aerobic nitrification processes. On the other hand, transformation of nitrite to nitrate is
the rate limiting step, and a comparison of nitrate to ammonia ratios revealed that these ratio
values were very different between the reference and random groups (Figure 26a).
Total nitrogen concentrations were also found to be significantly higher (Kruskal-Wallace p <
0.000) in the reference wetland population (1.88 mg/L) than in the random population (1.14
mg/L, Figure 26b). The CDF curves also suggest that these two groups are different (Figure 27).
Organic nitrogen, calculated as total nitrogen minus measured ammonia, nitrate, and nitrite
concentrations, was also significantly higher (Kruskal-Wallace p < 0.000), but the ratio of
dissolved nitrogen compounds to the organic nitrogen concentration was higher in the random
population. Combined, these measures of nitrogen concentrations demonstrate that cycling of
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Lacustrine Palustrine Riverine
Wetland Class