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Full-Text Articles in Earth Sciences

Riparian Conundra, David Weaver Jan 2010

Riparian Conundra, David Weaver

Conference papers and presentations

Riparian vegetation is established or restored on the basis that it physically filters and traps hillslope derived particulate nutrients in surface runoff. Whilst many studies support this conventional model of riparian function, few test this models embedded assumptions. The assumptions are that catchments are surface runoff dominated, that most surface derived nutrients are transported in particulate form, and that riparian management targets locations that will result in the greatest change in water quality. This paper reviews studies in south west Western Australia that challenge these assumptions. Plots measuring leaching and runoff of nutrients showed that 20 times more water and …


The Balancing Act, David Weaver Jan 2008

The Balancing Act, David Weaver

Conference papers and presentations

Nutrient management is as much a global issue as a local one with a balance required between economics and environment, inherent biological limitations and expectations of nutrient use efficiency, and traditional fertiliser practices and actual enterprise nutrient requirements. The concept of nutrient balance depends on context and scale. Nutrient balance can be considered at a global scale, where issues of nutrient stocks, cycles, depletion and transfer of a particular element are important. For a single farm enterprise, nutrient balance might be considered in terms of phosphorus (P) inputs into and outputs from the enterprise. This is commonly known as a …


Before And After Riparian Management: Sediment And Nutrient Exports From A Small Agricultural Catchment, Western Australia, Lucy Mckergow, David Weaver, I Prosser, R Grayson, A. E.G. Reed Jan 2001

Before And After Riparian Management: Sediment And Nutrient Exports From A Small Agricultural Catchment, Western Australia, Lucy Mckergow, David Weaver, I Prosser, R Grayson, A. E.G. Reed

Conference papers and presentations

Riparian vegetation can trap sediment and nutrients coming from hillslopes and reduce stream bank erosion. This study presents results from a 10 year stream monitoring program in a small agricultural catchment near Albany, Western Australia. In 1996, a 1.6 km stream reach was fenced, planted with eucalyptus species and managed separately from the adjacent paddocks. Stream flow, nutrient and sediment concentration data were collected at the downstream end of the fenced riparian area between 1991 and 2000, so there are data for the “before” and “after” riparian management periods. Suspended sediment concentrations fell dramatically following riparian management; the average event …


Relationships Between Stream Order And Management Priority: A Water Quality Case Study, David Weaver, Adrian Reed, John Grant Jan 2001

Relationships Between Stream Order And Management Priority: A Water Quality Case Study, David Weaver, Adrian Reed, John Grant

Conference papers and presentations

Seagrass, which once dominated the habitat of Oyster Harbour on the south coast of Western Australia has been replaced by macroalgae because of increased nutrient and sediment discharge from the rural dominated catchment. Total Phosphorus (TP), Total Nitrogen (TN), Suspended Sediment (SS) and Electrical Conductivity (EC) concentrations from a catchment – wide (168 sites), event-driven snapshot, water quality monitoring program conducted from 1994 to 1996, were analysed in relation to stream order and published survey data on riparian zone condition. This analysis was performed to examine relationships between stream order, riparian zone condition and water quality, and implications for the …