Emergent baskettail dragonfly
Twelve spotted skimmer dragonfly
Alysa Remsburg and Bridget Henning surveying for adult dragonflies along a Vilas county lake.
Example of shoreline transect
Use of riparian plant structures by Odonata in habitat selection
Contacts
Keywords
vegetation structure, habitat suitability, dragonflies, exurban development, generalist predators, behavioral ecology, insect diversity
Project Summary
Ph.D. student Alysa Remsburg's research stems from the Biocomplexity project headed by Steve Carpenter in the Center for limnology. The Biocomplexity project has focused on interactions between lakeshore vegetation and land use, and social and economic organizations of lake users. This work focuses on dragonflies and damselflies (order Odonata), which are voracious, generalist predators of other insects. The significance of plant structures for predaceous animal distributions is unclear, but could be particularly important for animals that move freely in three dimensions. As vegetation clearing accompanies shoreline development, more information is needed about the consequences for wildlife. Odonata diversity may serve as an indicator for the health of other aquatic and riparian species. Due to rapid dispersal, Odonates may be among the first organisms responding to habitat structural changes.
Primary research questions include:
- What are the effects of littoral and riparian vegetation structure on Odonata assemblage patterns in northern Wisconsin lakes?
- How does riparian structure influence odonate oviposition site-selection behavior?
Key Findings
- Dragonfly and damselfly larval assemblages at 46 northern Wisconsin lakeshore sites were affected by the presence of shrub-layer plants (0.7 – 2 m tall), but not simply by building presence. Littoral sites adjacent to both forests and lawns with shrubs had higher species richness (mixed-effects ANOVA F = 6.8; p = 0.004) and density (F = 6.2; p= 0.005) of odonate larvae than those next to lawns without shrubs. I found no significant relationships between Odonata assemblages and presence or absence of littoral macrophytes.
- Based on a shadecloth experiment in South Africa (where invasive Acacia trees have increased riparian shade levels), territorial dragonfly densities were negatively related to shade levels (F = 14.8, p < 0.0001). After erecting five types of stick treatments (two stick density levels x two stick diversity levels, plus one control without sticks) along the sandy reservoir shoreline, I found no effects of stick density or height on adult odonate behavior. There were, however, significantly higher adult odonate densities in all four of the treatments with sticks than in the control treatments without sticks (Kruskal-Wallis chi-squared = 13.7, p = 0.001).
Selected Publications
In progress
Acknowledgements
Alysa is extremely grateful for the ideas contributed by Monica Turner, Steve Carpenter, Michael Samways, Anders Olson, Bill Smith, Bob DuBois, Tony Ives, Claudio Gratton, Bobbi Peckarsky, and Joy Zedler. Outstanding field assistants have included Jasmine Batten and Bridget Henning. Funding from the UW North Temperate Lakes LTER research station at Trout Lake, National Science Foundation (NSF) Biocomplexity Program (grant number DEB-0083545), and NSF Graduate Research Fellowship made this research possible.