
Ecosystem Linkages
Aquatic insects are ubiquitous and abundant components of terrestrial communities that occur at the water-land interface. Despite their small size, as aquatic insects move over land and die, they can at times represent a relatively large contribution to ecosystem C and N fluxes, affect food web interactions on land, and alter the composition of plant and animal communities. Since 2005, we have been studying the annual emergences of chironomid (non-biting) midges from the subarctic lake Myvatn in northeastern Iceland to understand the ecosystem and food web effects on near-shore terrestrial ecosystems.
In addition to the awesome biology and ecology we can learn here, we think of ecosystem linkages between lakes and land as an example of ecosystem linkages more broadly – including those between diverse terrestrial habitats such as those we work on in Wisconsin. Conservation of insect biological control agents and pollinators rely, at their core, on understanding ecosystem linkages. Here at Myvatn the system is simpler and the interactions and drivers of processes easier to identify. This makes it an exciting and useful place to understand the ecological principles that are at play in linked systems.
Here are some of our publications from our work on ecosystem linkages at the water-land interface in Iceland:
Dreyer, J., D. Hoekman, and C. Gratton. 2015. Positive indirect effect of aquatic insects on terrestrial prey is not offset by increased predator density. Ecological Entomology doi:10.1111/een.12272
Dreyer, J., P. A. Townsend, J. C. Hook III, D. Hoekman, M. J. Vander Zanden, and C. Gratton. 2015. Quantifying aquatic insect deposition from lake to land. Ecology 96:499–509.
Bartrons, M., C. Gratton, B. J. Spiesman, and M. J. Vander Zanden. 2015. Taking the trophic bypass: aquatic-terrestrial linkage reduces methylmercury in a terrestrial food web. Ecological Applications 25:151–159.
Bultman, H., D. Hoekman, J. D. Dreyer, and C. Gratton. 2014. Terrestrial deposition of aquatic insects increases plant quality for insect herbivores and herbivore density. Ecological Entomology 39:419-426.
Dreyer, J. and C. Gratton. 2014. Habitat linkages in conservation biological control: lessons from the land-water interface. Biological Control 75: 68-76
Hoekman, D., M. Bartrons, and C. Gratton. 2012. Ecosystem linkages revealed by experimental lake-derived isotope signal in heathland food webs. Oecologia 170:735–743. doi: 10.1007/s00442-012-2329-5.
Hoekman, D., J. Dreyer, R. Jackson, P. Townsend, and C. Gratton. 2011. Lake to land subsidies: experimental addition of aquatic insects increases terrestrial arthropod densities. Ecology 92:2063-2072. doi: 10.1890/11-0160.1.
Vander Zanden, M. J., and C. Gratton. 2011. Blowin’ in the wind: Reciprocal airborne carbon fluxes between lakes and land. Canadian Journal of Fisheries & Aquatic Sciences 68:170-182. doi: 10.1139/F10-157.
Gratton, C., and M. J. Vander Zanden. 2009. Flux of aquatic insect productivity to land: comparison of lentic and lotic ecosystems. Ecology 90:2689-2699. doi: 10.1890/08-1546.1.
Gratton, C., J. Donaldson, and M. J. Vander Zanden. 2008. Ecosystem linkages between lakes and the surrounding terrestrial landscape in northeast Iceland. Ecosystems 11:764-774. doi: 10.1007/s10021-008-9158-8.
Lab blog and news for ecosystem linkages…

Iceland Work Featured by UMD Entomology!
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Talking Science: 2017 conferences thus far
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Dr. Claudio Gratton Receives Vilas Associate Award
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Welcome to our newest lab member, Matt!
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Welcome new PhD student, Amanda McCormick!
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2015 Field Season Preview
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Using isotopes to track nutrients
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Bring it On! Fall 2012
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PhD position available
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How did the Iceland project get started?
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Undergraduate Poster Session
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Midges connect aquatic and terrestrial food webs
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