GLACIAL RIVER ECOSYSTEMS IN ICELAND AND THE EFFECT OF GLOBAL WARMING ON THEIR BIOLOGICAL COMMUNITIES
It is predicted with global warming that glacial discharge will increase in the beginning, with increased suspended solids, increased instability of substrate and increased temperatures of alpine rivers and downstream in glacial rivers. In Iceland it is estimated that all glacial rivers will become non-glacial clear water rivers within 200 years. Studies on large glacial rivers in Iceland showed that types of species communities were determined with a few environmental variables, like bryophyte cover, temperature, distance from glacier snout and substrate stability. A few invertebrate taxa were highly adapted live in glacial rivers. They harboured low invertebrate diversity, low species heterogeneity traits illustrating strongly deterministic assembly processes. Increased melt water in the early faces of glacier retreat could lower invertebrate diversity further downstream in glacier rivers, leading to more homogenous species assemblage. However, decreased glacier melt water at later stages of glacier retreat may lead to higher invertebrate diversity, higher productivity similar to be found now in non-glacial rivers. The effect of deglaciation on the rivers biota will be discussed.
Gislason, G. M., University of Iceland, Iceland, firstname.lastname@example.org
Olafsson, J. S., Institute of Freshwater Fisheries, Iceland, email@example.com
Location: C 123 - 124
Presentation is given by student: No