Temporal changes between ecological regimes in a range of primary and secondary salinised wetlands
Authors
Karen Strehlow, Murdoch University
Jennifer Davis, Murdoch University
Lien Sim, Murdoch University
Jane Chambers, Murdoch University
Stuart Halse, Dept of conservation and Land Management
David Hamilton, University of Waikato
Pierre Horwitz, Edith Cowan UniversityFollow
Arthur McComb, Murdoch University
Raymond Froend, Edith Cowan UniversityFollow
Document Type
Journal Article
Publisher
Springer Verlag
Faculty
Faculty of Computing, Health and Science
School
School of Natural Sciences / Centre for Ecosystem Management
RAS ID
3421
Abstract
Many rivers and wetlands in south-western Australia are threatened by salinisation due to rising saline watertables, which have resulted from land clearing and the replacement of deep-rooted perennial species with shallow-rooted annual species. A four to six weekly sampling program of water quality, submerged macrophytes and macroinvertebrates was undertaken at six wetlands, from September 2002 to February 2004, to investigate seasonal variation in a range of primary and secondary saline systems. The wetlands dried and filled at different times in response to local rainfall patterns, and salinities varied accordingly with evapoconcentration and dilution. Two types of clear-water wetlands were recognised; those dominated by submerged aquatic macrophytes (Ruppia, Lepilaena and Lamprothamnium) and those dominated by benthic microbial communities. Two types of turbid wetlands were also recognised; those with high concentrations of phytoplankton and those with high concentrations of suspended sediments. A primary saline lake and two lakes that have only recently been affected by secondary salinisation persisted in a clear, macrophytedominated regime throughout most of the study period, except during drying and filling. Two lakes with a long history of secondary salinisation (70 years) moved between regimes over the study period. A clear, benthic microbial community – dominated regime only persisted at the wetland which contained permanent water throughout the study period. The turbid regimes were only present during drying and refilling phases. A richer and more abundant macroinvertebrate fauna was associated with the clear, macrophytedominated wetlands. Our results suggest that the development of management guidelines that recognise the presence of different ecological regimes and that consider the interactions between water regime, salinity, and primary and secondary production will be more useful in protecting biodiversity and ecological function in these systems than managing salinity as a single factor.
DOI
10.1007/s10750-005-1502-9
Comments
Strehlow, K., Davis, J., Sim, L., Chambers, J., Halse, S., Hamilton, D., Horwitz, P. , McComb, A., & Froend, R. H. (2005). Temporal changes between ecological regimes in a range of primary and secondary salinised wetlands. Hydrobiologia: the international journal on limnology and marine sciences , 552(1), 17-31. Available here".