Ephemeral ponds are small, isolated wetlands located in woodlands that usually lack fish (Colburn 2004). These ponds serve as a breeding habitat for both macroinvertebrates and amphibians. Amphibians contribute to the diversity of macroinvertebrates through predation, competition and elimination of potential macroinvertebrate predators (Dutra and
Callisto 2005). How amphibians affect the diversity of macroinvertebrates in ephemeral ponds is an important question, because both amphibians and macroinvertebrates play important roles in interaction webs as well as contribute to the biodiversity of the area (Petranka and Kennedy 1999).
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To understand how the presence of amphibians affects the diversity, overall community structure and composition and individual taxa abundance of macroinvertebrates in ephemeral ponds.
1. Determine if there is a relationship between taxa diversity and wood frog presence or absence.
2. Look at the effect of wood frog presence on overall community composition.
3. Determine which taxa the presence or absence of wood frog is associated with.
http://county-radon.info/WI/Chippewa.htm
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Figure 1: Chippewa County, Wisconsin
• There was no significant difference in diversity between wood frog presence and absence in ephemeral ponds (t-statistic= -0.34, p-value=
0.7, 95% confidence interval= -0.10, 0.07 (Figure 2)).
• There was not an overall pattern in community composition in ephemeral ponds with wood frogs compared to those that did not have wood frogs (Figures 3-5).
• Indicator species analysis revealed a significant positive association between wood frog presence and
and Haliplidae (pvalue >0.05).
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(Left) Figure 4: NMDS ordination of beetle and bug communities. The blue lines depict variation in Simpson
Diversity among wetlands, red circles indicate wetlands without wood frog tadpoles, and green circles indicate wetlands with wood frog tadpoles.
(Right) Figure 5: NMDS ordination of dipteran communities. The blue lines depict variation in Simpson Diversity among wetlands, red circles indicate wetlands without wood frog tadpoles, and green circles indicate wetlands with wood frog tadpoles.
• Although there is no significant difference between diversity and wood frog presence another study may be able to focus on richness and wood frog presence.
• There was no significance between wood frog presence and overall community composition, but there were two taxa that had a significant association with wood frog presence.
• Because this was an exploratory study further investigation should consider if the association between wood frog presence and
and Haliplidae was direct or environmental.
• Amphibians and aquatic macroinvertebrates were sampled from 41 ephemeral ponds in Chippewa County, Wisconsin
(Figure 1).
• Tadpoles were surveyed by using steel minnow traps with
1/8” mesh. Presence-absence of tadpoles were used in analyses here.
• Aquatic macroinvertebrates were sampled using surfaceassociated activity traps.
• Macroinvertebrate samples were processed in the lab using stereomicroscopes and individuals were identified to the lowest feasible taxonomic level.
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• Aquatic macroinvertebrate diversity was calculated using the Simpson’s diversity index.
• Mean diversity was compared to the presence/absence of wood frog tadpoles using the Welch’s t-test.
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• Aquatic invertebrate community composition was assessed using indirect gradient analysis.
• Non-metric multidimensional scaling (NMDS) was performed on subsets of the macroinvertebrates communities.
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• Indicators species analysis was used to explore whether the presence of wood frog tadpoles have a potential affect on individual taxa.
Figure 2: Comparison of macroinvertebrate diversity and wood frog presence.
• We thank Ashley Kijowski, Megen Hines, Amanda Smith, Adam
Cameron, Pam Gehant, Shelby Kilibarda, and Leta Ganrude for help in collecting data.
• 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 authors and do not necessarily reflect the views of the National
Science Foundation.
• Colburn, E. (2004). Vernal Pools: Natural History and Conservation.
The McDonald & Woodward Publishing Company, Blacksburg, VA and
Granville, OH
• Dutra, S., Callisto, M. (2005). “Macroinvertebrates as Tadpole food:
Importance and Body Size Relationships”. Revisita Brasileria de
Zoologia, 22(4): 923-927.
• Petranka, J., Kennedy, C. (1999). “Pond tadpoles with generalized morphology: is it time to reconsider their functional roles in aquatic communities?” Oecologia, 120: 621-631.
Figure 3: NMDS ordination of zooplankton communities. The blue lines depict variation in Simpson Diversity among wetlands, red circles indicate wetlands without wood frog tadpoles, and green circles indicate wetlands with wood frog tadpoles.