Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster E82

Surface and subsurface macroinvertebrate community differences across a thermal gradient in Icelandic streams.

Daniel P Govoni (1, 2), Bjarni Kristófer Kristjánsson (2), Jón S. Ólafsson (3), Mark S. Wipfli (1)

1. University of Alaska Fairbanks, 2. Háskólinn á Hólum, 3. Veiðimálastofnun

Kynnir / Presenter: Daniel P. Govoni

Tengiliður / Corresponding author: Daniel P. Govoni (dpgovoni@alaska.edu)

Invertebrate communities and food webs have been thoroughly studied in small streams, but there has been relatively little research done on the linkages between subsurface and surface communities (i.e., within hyporheic habitats). Hyporheic habitats may play a major role in shaping stream food webs and are likely susceptible to warming temperatures. Climate change and resource development could alter the linkages between surface and subsurface habitats upon which stream food webs depend. Understanding these linkages better, in the face of increasing development and climate change, will help inform aquatic resource management. The objectives of this study are to determine 1) how temperature influences invertebrate community assemblage, density, and diversity in the surface and subsurface of streams, and 2) how hyporheic communities and processes influence stream food webs. To address the objectives, we are studying streams on two spatial scales: landscape and catchment. In the landscape study, we are using thermally-stable and thermally-variable streams. In the catchment study, we are only using thermally-stable streams. At both scales, we selected streams that give us a thermal gradient across which to study community differences. We sample from four stations within each stream. At each station, we collect surface and subsurface samples at 25 and 50 cm below the streambed. Gut contents will be analyzed on four thermally-stable streams to describe food web dynamics.