Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences

Changes in organic-matter dynamics and physicochemistry, associated with riparian vegetation loss and river regulation in floodplain wetlands of the Murray River, Australia

Susanne C. Watkins A B D , G. P. Quinn C and Ben Gawne B

A School of Biological Sciences, Monash University, Clayton, Vic. 3800, Australia.

B Present address: The Murray–Darling Freshwater Research Centre, La Trobe University, PO Box 991, Wodonga, Vic. 3689, Australia.

C School of Life and Environmental Sciences, Deakin University, Warrnambool, Vic. 3280, Australia.

D Corresponding author. Email:

Marine and Freshwater Research 61(10) 1207-1217
Submitted: 18 December 2009  Accepted: 22 May 2010   Published: 14 October 2010


Extensive clearing of floodplain forests potentially reduces organic matter available to floodplain wetlands. Furthermore, on rivers regulated to provide irrigation water in summer, floodplain wetlands that were previously inundated in spring, now flood in summer/autumn. In the Murray–Darling Basin, Australia, this has changed the timing of organic matter entering the aquatic phase, since leaf fall peaks in summer. Field surveys and mesocosm experiments on floodplain wetlands on the River Murray revealed faster processing rates of leaves in summer/autumn than spring, and no difference between cleared and forested wetlands. Temperature and leaf carbon : nitrogen ratio could not explain these differences, and instead, changes to leaf chemistry associated with ‘terrestrial ageing’ between peak leaf fall in summer and inundation in spring is more likely. The results indicated that the reduction of input of organic matter through riparian tree clearing and changing the timing of inundation interact to alter organic-matter standing stocks and rates of decomposition in floodplain wetlands. Restoring both natural timing of high flows and riparian vegetation might be required for recovery of these wetlands.

Additional keywords: decomposition, dissolved oxygen, Eucalyptus camaldulensis, mesocosm, restoration.


Arthington A. H.Pusey B. J.2003Flow restoration and protection in Australian rivers.River Research and Applications19377395doi:10.1002/RRA.745

Baldwin D. S.1999Dissolved organic matter and phosphorus leached from fresh and ‘terrestrially’ aged river red gum leaves: implications for assessing river-floodplain interactions.Freshwater Biology41675685doi:10.1046/J.1365-2427.1999.00404.X

Ballantine K.Schneider R.2009Fifty-five years of soil development in restored freshwater depressional wetlands.Ecological Applications1914671480doi:10.1890/07-0588.1

Bayley P. B.1995Understanding large river-floodplain ecosystems.BioScience45153159doi:10.2307/1312554

Boon P. I.Sorrell B. K.1991Biogeochemistry of billabong sediments I. The effect of macrophytes.Freshwater Biology26209226doi:10.1111/J.1365-2427.1991.TB01730.X

Boon P. I., Frankenberg J., Hillman T. J., Oliver R. L., and Shiel R. J. (1990). Billabongs. In ‘The Murray’. (Eds N. Mackay and D. Eastburn.) pp. 183–198. (Murray Darling Basin Commission: Canberra.)

Borneman J.Triplett E. W.1997Molecular microbial diversity in soils from eastern Amazonia: evidence for unusual microorganisms and microbial population shifts associated with deforestation.Applied and Environmental Microbiology6326472653

Boulton A. J.Boon P. I.1991A review of methodology used to measure leaf litter decomposition in lotic environments: time to turn over an old leaf?Australian Journal of Marine and Freshwater Research42143

Briggs S. V.Maher M. T.1983Litter fall and leaf decomposition in a river red gum (Eucalyptus camaldulensis) swamp.Australian Journal of Botany31307316doi:10.1071/BT9830307

Bunn S. E. (1986). Origin and fate of organic matter in Australian upland streams. In ‘Limnology in Australia’. (Eds P. De Deckker and W. D. Williams.) pp. 277–291. (CSIRO Australia/Dr W. Junk Publishers: Melbourne.)

Campbell I. C.Fuchshuber L.1994Amount, composition and seasonality of terrestrial litter accession to an Australian cool temperate rainforest stream.Archiv fuer Hydrobiologie130499512

Campbell I. C.Fuchshuber L.1995Polyphenols, condensed tannins, and processing rates of tropical and temperate leaves in an Australian stream.Journal of the North American Benthological Society14174182

Campbell I. C.James K. R.Hart B. T.Devereaux A.1992Allochthonous coarse particulate organic material in forest and pasture reaches of two south-eastern Australian streams. I. Litter accession.Freshwater Biology27341352doi:10.1111/J.1365-2427.1992.TB00544.X

Chergui H.Pattee E.1990The influence of season on the breakdown of submerged leaves.Archiv fuer Hydrobiologie120112

Cummins K. W.1973Trophic relations of aquatic insects.Annual Review of Entomology18183206

Eaton A. D., and Franson M. A. H. (2005). ‘Standard Methods for the Examination of Water and Wastewater.’ 21st centennial edn. (American Public Health Association, American Water Works Association, Water Environment Federation: Washington, DC.)

Fisher S. G.Likens G. E.1973Energy flow in Bear Brook, New Hampshire: an integrative approach to stream ecosystem metabolism.Ecological Monographs43421439doi:10.2307/1942301

Francis C.Sheldon F.2002River red gum (Eucalyptus camaldulensis Dehnh.) organic matter as a carbon source in the lower Darling River, Australia.Hydrobiologia481113124doi:10.1023/A:1021269205983

Gehrke P. C.Revell M. B.Philbey A. W.1993Effects of river red gum, Eucalyptus camaldulensis, litter on golden perch, Macquaria ambigua.Journal of Fish Biology43265279doi:10.1111/J.1095-8649.1993.TB00427.X

Glazebrook H. S.Robertson A. I.1999The effect of flooding and flood timing on leaf litter breakdown rates and nutrient dynamics in a river red gum (Eucalyptus camaldulensis) forest.Australian Journal of Ecology24625635doi:10.1046/J.1442-9993.1999.00992.X

Golladay S. W.Webster J. R.Benfield E. F.Swank W. T.1992Changes in stream stability following forest clearing as indicated by storm nutrient budgets.Archiv fuer Hydrobiologie90Suppl.133

Growns J. E.Davis J. A.Cheal F.Schmidt L. G.Rosich R. al.1992Multivariate pattern analysis of wetland invertebrate communities and environmental variables in Western Australia.Australian Journal of Ecology17275288

Herbst G.Reice S. R.1982Comparative leaf litter decomposition in temporary and permanent streams in semi-arid regions of Israel.Journal of Arid Environments5305318

Hillman T. J. (1986). Billabongs. In ‘Limnology in Australia’. (Eds P. De Deckker and W. D. Williams.) pp. 457–470. (CSIRO Australia/Dr W. Junk Publishers: Melbourne.)

Hosomi M.Sudo R.1986Simultaneous determination of total nitrogen and total phosphorus in freshwater samples using persulfate digestion.International Journal of Environmental Studies27267275

Howitt J. A.Baldwin D. S.Rees G. N.Williams J. L.2007Modelling blackwater: predicting water quality during flooding of lowland river forests.Ecological Modelling203229242doi:10.1016/J.ECOLMODEL.2006.11.017

Janssen M. A.Walker K. F.1999Processing of riparian and wetland plant litter in the River Murray, South Australia.Hydrobiologia4115364doi:10.1023/A:1003891720922

Kiffney P. M.Richardson J. S.Bull J. P.2003Responses of periphyton and insects to experimental manipulation of riparian buffer width along forest streams.Journal of Applied Ecology4010601076doi:10.1111/J.1365-2664.2003.00855.X

Lake P. S.1982The 1981 Jolly Award Address. Ecology of the macroinvertebrates of Australian upland streams: a review of current knowledge.Bulletin of the Australian Society for Limnology8115

Lake P. S. (1995). Of floods and droughts: river and stream ecosystems of Australia. In ‘River and Stream Ecosystems of the World’. (Eds C. E. Cushing, K. W. Cummins and G. W. Minshall.) pp. 659–694. (Elsevier Science: Amsterdam.)

Leff L. G.McArthur J. V.1990Effect of nutrient content on leaf decomposition in a coastal-plain stream: a comparison of green and senescent leaves.Journal of Freshwater Ecology5269277

Lowe R. L.Golladay S. W.Webster J. R.1986Periphyton response to nutrient manipulation in streams draining clearcut and forested watersheds.Journal of the North American Benthological Society5221229

Maheshwari B. L.Walker K. F.McMahon T. A.1995Effects of regulation on the flow regime of the River Murray, Australia.Regulated Rivers: Research and Management101538doi:10.1002/RRR.3450100103

McCarthy B.Conallin A.D’Santos P.Baldwin D. S.2006Acidification, salinization and fish kills at an inland wetland in south-eastern Australia following partial drying.Ecological Management & Restoration7218223doi:10.1111/J.1442-8903.2006.312_1.X

Meyer J. L.1990A blackwater perspective on riverine ecosystems.BioScience40643651doi:10.2307/1311431

Mitsch W. J., and Gosselink J. G. (2000). ‘Wetlands.’ (John Wiley & Sons, Inc.: New York.)

O’Connell M.Baldwin D. S.Robertson A. I.Rees G.2000Release and bioavailability of dissolved organic matter from floodplain litter: influence of origin and oxygen levels.Freshwater Biology45333342doi:10.1111/J.1365-2427.2000.00627.X

Patrick R.Binetti V. P.Halterman S. G.1981Acid lakes from natural and anthropogenic causes.Science211446448doi:10.1126/SCIENCE.211.4481.446

Petersen R. C.Cummins K. W.1974Leaf processing in a woodland stream.Freshwater Biology4343368doi:10.1111/J.1365-2427.1974.TB00103.X

Poff N. L.Allan J. D.Bain M. B.Karr J. R.Prestegaard K. al.1997The natural flow regime.BioScience47769784doi:10.2307/1313099

Pressland A. J.1982Litter production and decomposition from an overstorey of Eucalyptus spp. on two catchments in the New England region of New South Wales.Australian Journal of Ecology7171180doi:10.1111/J.1442-9993.1982.TB01590.X

Quinn G. P., and Keough M. J. (2002). ‘Experimental Design and Data Analysis for Biologists.’ (Cambridge University Press: Cambridge.)

Reid D. J.Lake P. S.Quinn G. P.Reich P.2008Association of reduced riparian vegetation cover in agricultural landscapes with coarse detritus dynamics in lowland streams.Marine and Freshwater Research599981014doi:10.1071/MF08012

Robertson A. I.Bunn S. E.Boon P. I.Walker K. F.1999Sources, sinks and transformations of organic carbon in Australian floodplain rivers.Marine and Freshwater Research50813829doi:10.1071/MF99112

Specht R. L.Brouwer Y. M.1975Seasonal shoot growth of Eucalyptus spp. in the Brisbane area of Queensland (with notes on shoot growth and litter fall in other areas of Australia).Australian Journal of Botany23459474doi:10.1071/BT9750459

Sweeney B. W.1993Effects of streamside vegetation on macroinvertebrate communities of White Clay Creek in eastern North-America.Proceedings. Academy of Natural Sciences of Philadelphia144291340

Sweeney B. W.Bott T. L.Jackson J. K.Kaplan L. A.Newbold J. al.2004Riparian deforestation, stream narrowing, and loss of stream ecosystem services.Proceedings of the National Academy of Sciences, USA10114 13214 137

Tockner K.Stanford J. A.2002Riverine flood plains: present state and future trends.Environmental Conservation29308330doi:10.1017/S037689290200022X

Townsend S. A.Boland K. T.Wrigley T. J.1992Factors contributing to a fish kill in the Australian wet/dry tropics.Water Research2610391044doi:10.1016/0043-1354(92)90139-U

Upchurch R.Chi C. Y.Everett K.Dyszynski G.Coleman D. al.2008Differences in the composition and diversity of bacterial communities from agricultural and forest soils.Soil Biology & Biochemistry4012941305doi:10.1016/J.SOILBIO.2007.06.027

Walker J.Bullen F.Williams B. G.1993Ecohydrological changes in the Murray–Darling Basin. 1. The number of trees cleared over 2 centuries.Journal of Applied Ecology30265273doi:10.2307/2404628

Wallace J. B.Eggert S. L.Meyer J. L.Webster J. R.1999Effects of resource limitation on a detrital-based ecosystem.Ecological Monographs69409442doi:10.1890/0012-9615(1999)069[0409:EORLOA]2.0.CO;2

Wallace T. A.Ganf G. G.Brookes J. D.2008A comparison of phosphorus and DOC leachates from different types of leaf litter in an urban environment.Freshwater Biology5319021913doi:10.1111/J.1365-2427.2008.02006.X

Webster J. R.Benfield E. F.1986Vascular plant breakdown in freshwater ecosystems.Annual Review of Ecology and Systematics17567594doi:10.1146/ANNUREV.ES.17.110186.003031

Wieder R. K.Lang G. E.1982A critique of the analytical methods used in examining decomposition data obtained from litter bags.Ecology6316361642doi:10.2307/1940104

Wood P. J.Armitage P. D.1997Biological effects of fine sediment in the lotic environment.Environmental Management21203217doi:10.1007/S002679900019

Export Citation Cited By (10)