COS 63-5 - Temporal patterns and environmental correlates of macroinvertebrate communities in temporary streams

Thursday, August 11, 2016: 9:20 AM
304, Ft Lauderdale Convention Center

ABSTRACT WITHDRAWN

Paul K. Botwe1, Leon A. Barmuta1, Regina Magierowski1,2, Paul McEvoy3, Peter Goonan4 and Scott Carver5, (1)School of Biological Sciences, University of Tasmania, Hobart, Australia, (2)Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, Australia, (3)Department of Environment, Water and Natural Resources, Government of South Australia, Adelaide, Australia, (4)Environment Protection Authority, Government of South Australia, Adelaide, Australia, (5)School of Natural Sciences, University of Tasmania, Hobart, Australia
Paul K. Botwe, University of Tasmania; Leon A. Barmuta, University of Tasmania; Regina Magierowski, University of Tasmania, La Trobe University; Paul McEvoy, Government of South Australia; Peter Goonan, Government of South Australia; Scott Carver, University of Tasmania

Background/Question/Methods

Temporary streams are characterised by short periods of seasonal or annual stream flow after which streams contract into waterholes or pools of varying hydrological connectivity and permanence. Although these streams are widespread globally, temporal variability of their ecology is understudied, and understanding the processes that structure community composition in these systems is vital for predicting and managing the consequences of anthropogenic impacts. We used multivariate and univariate approaches to investigate temporal variability in macroinvertebrate compositional data from 13 years of sampling across multiple sites from autumn and spring, in South Australia, the driest state in the driest inhabited continent in the world. We examined the potential of land-use, geographic and environmental variables to predict the temporal variability in macroinvertebrate assemblages, and also identified indicator taxa, that is, those highly correlated with the most significantly associated physical variables.

Results/Conclusions

Temporal trajectories of macroinvertebrate communities varied within site in both seasons and across years. A combination of land-use, geographic and environmental variables accounted for 24% of the variation in community structure in autumn and 27% in spring. In autumn, community composition among sites were more closely clustered together relative to spring suggesting that communities were more similar in autumn than in spring. In both seasons, community structure was most strongly correlated with conductivity and latitude, and community structure was more associated with cover by agriculture than urban land-use. Maintaining temporary streams will require improved catchment management aimed at sustaining seasonal flows and critical refuge habitats, while also limiting the damaging effects from increased agriculture and urban developments.