Spatial Gradients in Wetland Water Chemistry Attributes Across a Landscape Gradient of
Permanent and Ephemeral Wetlands
Megen Hines, Dr. Amanda Little, Dr. James Church, Biology Dept., University of Wisconsin-Stout
Introduction
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Ephemeral ponds contain species important to global biodiversity and can act as
dispersal route for some species (Williams 2006)
Macro-invertebrate, amphibian, and plant species have adapted to survive in specific
physiochemical environments
Ephemeral ponds exhibit large fluctuations in physiochemical attributes among ponds
and between years (Magnusson and Williams 2006)
Physiochemical attributes influence wetland habitat and macro-invertebrate,
amphibian, and plant communities
Hydroperiod, water depth, substrate, and basin morphology influence physiochemical
environment attributes (Magnusson and Williams 2006)
Exploratory study to investigate potential differences in wetland water chemistry
among permanent and ephemeral ponds
Results
Variable
pH
Conductivity
Nitrate
Ammonium
TP
SRP
Dissolved Oxygen
Ephemeral
5.533-6.856
21.417-72.222 µS
2.289-23.167 ppm
0.040-2.305 ppm
0.151-1.505 mg/L
0-1.006 mg/L
0.842-4.538 mg/L
Permanent
5.725-7.083
16.111-42.111 µS
2.922-10.633 ppm
0.055-1.100 ppm
0-0.725 mg/L
0-0.525mg/L
1.831-7.209 mg/L
Figure 9. IDW map of SRP in permanent ponds. SRP
negatively correlated to latitude and longitude.
Differences in physiochemical environment could be due to hydroperiod length, water
depth, substrate, and catchment size
• Further Research Ideas
• Add water chemistry data from additional field seasons to analyze differences among
ponds and between years
• Create basin model to determine catchment size
• Investigate soil characteristics on an individual study site scale
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Objectives
Examine spatial gradient of water chemistry attributes
Quantify spatial variability of physiochemical wetland characteristics
• 57 forested permanent and ephemeral wetlands
• Chippewa Moraine, Wisconsin, USA
In situ measurements:
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Dissolved oxygen, pH, Conductivity
Lab analysis:
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Soluble reactive phosphorus (SRP)
• Ascorbic acid method (APHA 2005)
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Total Phosphorus (TP)
• Potassium persulfate digestion (Ameel et al. 1993)
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Nitrate-Probe
• Statistical Analysis
• Linear models to relate physiochemical characteristics to spatial attributes
• Inverse Distance Weighted (IDW) maps of environmental variables in ArcMap
Figure 8. IDW map of SRP in ephemeral ponds. No
significant relationship.
Conclusions
Figure 1. Aerial map of permanent and ephemeral ponds studied
within the Chippewa Moraine.
Methods
Figure 7. IDW map of conductivity in permanent
ponds. Conductivity negatively correlated to latitude.
Table 1. Data ranges for physiochemical variables in ephemeral and
permanent ponds.
Significant correlations:
• pH
• Ephemeral ponds positively correlated to latitude and longitude (P < 0.001,
Adjusted R2 = 0.317)
• Permanent ponds positively correlated to latitude (P = 0.009, R2 = 0.417)
• Nitrate
• Ephemeral ponds positively correlated to latitude (P = 0.036, R2 = 0.111)
• Conductivity
• Permanent ponds negatively correlated to latitude (P = 0.014, R2 = 0.384)
• SRP
• Permanent ponds negatively correlated to latitude and longitude (P = 0.031,
Adjusted R2 = 0.347)
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Figure 6. IDW map of conductivity in ephemeral
ponds. No significant relationship.
Figure 2. IDW map of pH in ephemeral ponds. pH
positively correlated to latitude and longitude.
Figure 3. IDW map of pH in permanent ponds. pH
positively correlated to latitude.
Acknowledgements
I would like to thank Elizabeth Usborne for GIS and graphics help. Thanks to Ashley Kijowski, Amanda Smith,
Pam Gehant, Adam Cameron, Shelby Kilibarda, and Leta Ganrude for assistance in field data collection and
lab analysis. Brenda Rederer and Rod Gont, WI DNR Ice Age Interpretive Center provided logistical
assistance. The University of Wisconsin-Stout College of Science, Technology, Engineering, and Mathematics,
and the Department of Biology provided support for this project.
This material is based upon work supported by the National Science Foundation under Grant 1256142. Any
opinions , findings, and conclusions or recommendations expressed in this material are those of the
author(s) and do not necessarily reflect the views of the National Science Foundation
Literature Cited
Figure 4. IDW map of nitrate in ephemeral ponds.
Nitrate positively correlated with latitude.
Figure 5. IDW map of nitrate in permanent ponds.
No significant relationship.
Ameel, et al. 1993 Persulfate digestion for determination of total nitrogen and phosphorus in low nutrient waters.
Amer. Environ. Lab. 10: 1-11
APHA. 2005. Standard Methods for the Examination of Water and Wastewater, 21st Ed. American Public Health
Association, Washington, DC
Magnusson, A.K., and D.D. Williams. 2006. The roles of natural temporal and spatial variation versus biotic influences in
shaping the physicochemical environment of intermittent ponds: a case study. Archiv fur Hydrobiologie
165:537-556
Williams, D. D. 2006. The biology of temporary waters. Oxford University Press, New York, New York, USA