Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
RESEARCH ARTICLE

Association of reduced riparian vegetation cover in agricultural landscapes with coarse detritus dynamics in lowland streams

D. J. Reid A C , P. S. Lake A , G. P. Quinn B and P. Reich A
+ Author Affiliations
- Author Affiliations

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

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

C Corresponding author. Email: davidjonreid@hotmail.com

Marine and Freshwater Research 59(11) 998-1014 https://doi.org/10.1071/MF08012
Submitted: 22 January 2008  Accepted: 16 August 2008   Published: 27 November 2008

Abstract

Studies were conducted on streams flowing through agricultural floodplains in south-eastern Australia to quantify whether reductions in riparian canopy cover were associated with alterations to the input and benthic standing stocks of coarse allochthonous detritus. Comparisons were made among three farmland reaches and three reaches within reserves with intact cover of remnant overstorey trees. Detritus inputs to these reaches were measured monthly over 2 years using litter traps. Direct inputs to streams within the reserves were relatively high (550–617 g ash free dry weight (AFDW) m–2 year–1), but were lower at farmland reaches with the lowest canopy covers (83–117 gAFDW m–2 year–1). Only a minor fraction of the total allochthonous input (<10%) entered any of the study reaches laterally. The mean amounts of benthic detritus were lowest in the most open farmland reaches. Standing stocks of benthic detritus were found to be highly patchy across a large number of agricultural streams, but were consistently very low where the streamside canopy cover was below ~35%. Canopy cover should be restored along cleared agricultural streams because allochthonous detritus is a major source of food and habitat for aquatic ecosystems. Given the absence of pristine lowland streams in south-eastern Australia, those reaches with the most intact remnant overstorey canopies should be used to guide restoration.

Additional keywords: allochthonous input, canopy cover, coarse particulate organic matter, Eucalyptus camaldulensis, litter trap.


Acknowledgements

This research was funded by Monash University and the Co-operative Research Centre for Freshwater Ecology while D. J. Reid held a Monash Postgraduate Scholarship. Financial assistance for this study was also provided by the Murray-Darling Basin Commission. Thank you to the Goulburn-Broken CMA, Lachlan CMA, Murray CMA and North Central CMA for supporting this research and to the many landholders who kindly provided access through their properties. Thanks also to all those who helped with field and laboratory work, and to Peter Domelow for help with constructing the litter traps. The suggestions of three anonymous reviewers and Andrew Boulton helped to improve the quality of the manuscript.


References

Anderson, N. H. , and Sedell, J. R. (1979). Detritus processing by macroinvertebrates in stream ecosystems. Annual Review of Entomology 24, 351–377.
Crossref | GoogleScholarGoogle Scholar | Bren L. (1990). Red gum forests. In ‘The Murray’. (Eds N. Mackay and D. Eastburn.) pp. 231–242. (Murray Darling Basin Commission: Canberra.)

Briggs, S. V. , and Maher, M. T. (1983). Litter fall and leaf decomposition in a River Red Gum (Eucalyptus camaldulensis) swamp. Australian Journal of Botany 31, 307–316.
Crossref | GoogleScholarGoogle Scholar | CAS | Brooks S. S. (1997). Impacts of flood disturbance on the macroinvertebrate assemblage of an upland stream. Ph.D. Thesis, Monash University, Clayton, Victoria.

Brooks, S. S. , and Lake, P. S. (2007). River restoration in Victoria, Australia: change is in the wind, and none too soon. Restoration Ecology 15, 584–591.
Crossref | GoogleScholarGoogle Scholar | 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 Publishing: East Melbourne.)

Bunn, S. E. (1993). Riparian–stream linkages: research needs for protection of in-stream values. Australian Biologist 6, 46–51.
Costermans L. (1983). ‘Native Trees and Shrubs of South-eastern Australia.’ (New Holland Publishers (Australia): Frenchs Forest.)

Cummins, K. W. (1974). Structure and function of stream ecosystems. Bioscience 24, 631–641.
Crossref | GoogleScholarGoogle Scholar | Frazer G. W., Canham C. D., and Lertzman K. P. (1999). ‘Gap Light Analyzer (GLA): Imaging Software to Extract Canopy Structure and Gap Light Transmission Indices from True-colour Fisheye Photographs, User’s Manual and Program Documentation.’ (Simon Fraser University: Burnaby.)

Graça, M. A. S. (1993). Patterns and processes in detritus-based stream systems. Limnologica 23, 107–114.
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. (University of California Press: Berkeley.)

Lake, P. S. , Barmuta, L. A. , Boulton, A. J. , Campbell, I. C. , and St Clair, R. M. (1986). Australian streams and Northern Hemisphere stream ecology: comparisons and problems. Proceedings of the Ecological Society of Australia 14, 61–82.
Quinn G. P., and Keough M. J. (2002). ‘Experimental Design and Data Analysis for Biologists.’ (Cambridge University Press: Cambridge.)

Read, M. G. , and Barmuta, L. A. (1999). Comparisons of benthic communities adjacent to riparian native eucalypt and introduced willow vegetation. Freshwater Biology 42, 359–374.
Crossref | GoogleScholarGoogle Scholar | Webster J. R., Wallace J. B., and Benfield E. F. (1995). Organic processes in streams of the eastern united states. In ‘River and Stream Ecosystems of the World’. (Eds C. E. Cushing, K. W. Cummins and G. W. Minshall.) pp. 117–187. (University of California Press: Berkeley.)

Webster, J. R. , Benfield, E. F. , Ehrman, T. P. , Schaeffer, M. A. , and Tank, J. L. , et al. (1999). What happens to allochthonous material that falls into streams? A synthesis of new and published information from Coweeta. Freshwater Biology 41, 687–705.
Crossref | GoogleScholarGoogle Scholar | Williams W. D. (1968). ‘Australian Freshwater Life: The Invertebrates of Australian Inland Waters.’ (Sun Books: Melbourne.)