Water requirements of biota, geomorphology and climate change in the Macquarie Marshes

Authors

Kerrylee Rogers, NSW Department of Environment, Climate Change & Water (DECCW)Follow
Tim Ralph, NSW Department of Environment, Climate Change & Water (DECCW)
Sarah Imgraben, NSW Department of Environment, Climate Change & Water (DECCW)

RIS ID

78061

Publication Details

Rogers, K., Ralph, T. J. & Imgraben, S. (2010). Water requirements of biota, geomorphology and climate change in the Macquarie Marshes. In N. Saintilan & I. Overton (Eds.), Ecosystem Response Modelling in the Murray-Darling Basin (pp. 151-170). Collingwood, Vic: CSIRO Publishing.

Abstract

The Macquarie Marshes, on the lower reaches of the Macquarie River, are the largest and one of the most ecologically significant f loodplain wetland systems in the Murray-Darling Basin of south-east Australia. All wetlands, such as the Macquarie Marshes, rely on the supply of water for their long-term survival (Mitsch and Gosselink 2000) and distinct f lood events provide inundation which maintains their ecological character. In accordance with the f lood pulse concept (Junk et al. 1989), f looding is the 'principal driving force responsible for the existence, productivity and interactions of the major biota' (Junk et al. 1989, p. 110) in most f loodplain wetlands. Although the f lood pulse concept theoretically does not apply to river systems with highly variable f low regimes, Walker et al. (1995) proposed that biota in variable environments and habitats develop strategies such as opportunism and f lexibility as adaptations to f low variability. They suggest that the f lood pulse concept may apply to f loodplains with variable f low regimes, such as the Macquarie Marshes. To adequately account for the ecological role of f looding on f loodplain biota, Junk et al. (1989, p. 112) claimed that 'the resulting physicochemical environment causes the biota to respond by morphological, anatomical, physiological, phenological, and/or ethological adaptations, and produce characteristic community structures' in f loodplain wetlands. Thus, ecosystems such as those in the Macquarie Marshes are likely to be both shaped and sustained by f loodwaters from upstream, since these f lows inf luence the wetland environments within the system.