Thursday, May 29, 2008 - 10:15 AM
526

The organisation of river networks: Is stream order a meaningful classification for stream ecology?

Michael J., Stewardson1, Angus Webb2, Janet Stein3, Stephen Wealands2, and Ian Rutherfurd2. (1) Civil and Environmental Engineering, eWater CRC, The University of Melbourne, Australia, (2) School of Social and Environmental Equiry, eWater CRC, The University of Melbourne, Australia, (3) The Fenner School of Environment and Society, Australian National University, Canberra, Australia

Stream order is the most widely used method for describing position within a river network for ecological investigations. It is used internationally to identify the position of a site with a river network. First order streams are considered to be small upland streams. Increasing stream order is expected to have a direct relation with stream size and an inverse relation with channel gradient. This study tests this notion that stream order relates to variations in environmental conditions of significance to stream biota. We model hydrological, geomorphic and water quality metrics of relevance to stream biota, throughout the rivers of South-East Australia and assess the capacity for stream order to represent patterns in these environmental variables. These tests are carried out within individual basins and across the region. We compare the performance of stream order with other descriptors of position in the river network. Our results highlight the limitations of stream order and its generality across regions.


Web Page: river network, stream order, environmental variation

See more of Landscapes I
See more of Contributed Sessions

See more of The Nabs 56th Annual Meeting (25-28 May, 2008)