Nutrients are exchanged between ecosystems in many ways.
The direction and magnitude of fluxes across the landscape can dramatically influence ecosystem processes. In Lake Myvatn in northern Iceland, an abundance of midges (in Icelandic, ‘my’ is midge, and ‘vatn’ is lake) emerge from the lake on a boom-and-bust cycle approximately every 7 years and create a visible ‘ring’ of enhanced vegetation growth around the the lake due to a nutrient subsidy from midges deposited on land.

From 2008 to 2011 we measured midge emergence from the lake and their subsequent deposition on land. We developed a model to map midge deposition as a function of distance-from-lake and wind direction. As well, we employed ASTER, Landsat, and Hyperion imagery to map foliar nitrogen, species composition, and aboveground biomass around the lake. The results show the strong influence of midge movement from lake to land on terrestrial ecosystem dynamics, the effects of which are clearly visible in spaceborne satellite imagery.

Contacts: Clayton Kingdon, Phil Townsend

Collaborators:

• Claudio Gratton
• Randy Jackson
• Tony Ives