CS34 River Dynamics
Date: Wednesday, June 12, 2002
Time: 3:15:00 PM
Location: View Royal
 
BrunkeM, Institute of Freshwater Ecology and Inland Fisheries, Berlin, GERMANY, brunke@igb-berlin.de
Fischer, H, , Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany, fischer@igb-berlin.de
Wilczek, S, , Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany, wilczek@igb-berlin.de
Pusch, M, , Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany, pusch@igb-berlin.de
 
ROLE OF HABITAT DIVERSITY, NUTRITIONAL RESOURCES AND DISTURBANCE REGIME FOR INVERTEBRATES IN A LARGE LOWLAND RIVER
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A habitat templet model was developed to assess the role played by nutritional and physical habitat factors and disturbance for benthic invertebrate assemblages in the Elbe River (Germany). The model integrates: (i) the supply of several kinds of nutritional resources, and (ii) the characteristics of the physical habitat regarding to hydraulic and geomorphic descriptors. Invertebrate abundances were investigated in three principal mesoscale habitats comprising groyne fields, migrating subaqueous dunes in mid-channel, and local, less instable subaqueous dunes. These mesohabitats were composed of several microhabitats, because of a different exposure to disturbances: The groyne fields were exposed to a strong gradient of hydraulic disturbance, which was effected by wakes and waves induced by navigation. The migrating dunes were ecologically in a state of permanent disturbance, owing to their fast movement. The disturbance regime of local dunes was caused by spatially distinct erosional, transport and depositional processes at the stoss, plateau and lee sides. Hydrogeomorphic factors appeared to be more important than the availability of nutritional resources for differences in the assemblage structure between habitats.