Spatiotemporal variability and environmental determinants of invertebrate assemblage structure in an Australian dry-tropical river

Journal Publication ResearchOnline@JCU
Davis, Aaron M.;Pearson, Richard G.;Kneipp, Ian J.;Benson, Lee J.;Fernandes, Leanne
Abstract

We described invertebrate assemblage composition over a range of spatial and temporal scales in the Burdekin River, one of northern Australia's large and variable dry-tropical river systems. Invertebrates were abundant but not diverse, and the assemblage structure exhibited considerable variability in space and time. Substratum and historical flow characteristics were important environmental factors influencing assemblage structure. The effect of substratum on invertebrate assemblage composition appears to be complex and operates over multiple spatial scales within the riverine habitat hierarchy. The fauna differed significantly among the major mesohabitat types (cobble, bedrock, and sand substrata), but divergent microhabitat-scale preferences of some taxa for finer or coarser sandy sediments demonstrated the importance of small-scale local factors in structuring invertebrate assemblages. The significant influence of antecedent hydrology coupled with pronounced spatial variation in site assemblage composition between qualitatively similar mesohabitats suggest that biomonitoring in variable, sand-bed rivers will benefit from standardization of sampling in relation to explicit flow and substratum characteristics to assess spatial and temporal changes in assemblages adequately.

Journal

Freshwater Science

Publication Name

Freshwater Science

Volume

34

ISBN/ISSN

2161-9565

Edition

N/A

Issue

2

Pages Count

14

Location

N/A

Publisher

North American Benthological Society

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Publisher Location

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Publish Date

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Url

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Date

N/A

EISSN

N/A

DOI

10.1086/681303