Physical Sciences and Mathematics Commons^™

Degradation Of Remnant Vegetation, Richard George, Don Mcfarlane, Russell Speed

Journal of the Department of Agriculture, Western Australia, Series 4

Remnant vegetation, wetlands and riverine systems on both private and public land throughout south-western Australia are being rapidly degraded by dryland salinity, inundation, silting, nutrient enrichment and weed invasion. Richard George, Don McFarlane and Russel Speed outline some of the reasons why this is happening and provide some case studies that highlight actions to protect these remnants.

Cooperative Landcare Venture Revisited, Kate Mcinnes

Journal of the Department of Agriculture, Western Australia, Series 4

Four years ago, the Journal of Agriculture reported on a unique partnership forged in 1989 between the Department of Agriculture Alcoa of Australia Limited and six catchment groups located in the Avon River catchment.

Kate McInnes reports on progress with the Avon Catchment Landcare Project.

How Sustainable Is Grazing Sheep On Annual Pastures In The Woolbelt?, Don Mcfarlane, Richard George

Journal of the Department of Agriculture, Western Australia, Series 4

Low wool prices have reduced the profitability of producing wool from clover-based annual pastures in the south-western woo/belt. The heavy reliance on one commodity is economically unsustainable for many farmers. But we should also consider how ecologically sustainable the practice is.

Shallow-rooted annual pastures contribute to widespread salinity in the area, annual legumes are acidifying the soils and making them water repellent, and bare, detached soils from heavy grazing cause sheet and rill erosion during autumn storms. In addition, stock are degrading remnant vegetation and destroying the soil's structure.

To counteract this degradation, the woo/belt needs more perennial pastures and …

Pastoral Land Degradation: The Fitzroy As A Case Study, Alan L. Payne, Ronald B. Hacker

Journal of the Department of Agriculture, Western Australia, Series 4

When large numbers of domestic livestock are superimposed on native vegetation in semi-arid and arid areas of the world, the ecological balance inevitably changes. In extreme cases these changes include such degradation as drastic losses of vegetation and active soil erosion. Areas affected in this way are unproductive for most purposes.

Western Australia's Fitzroy River valley has deteriorated in this way. Today, this once-­productive grazing country is so degraded that it has become a matter of concern to Governments, the pastoral industry and others.

This article gives a brief history of land degradation in parts of the Fitzroy River valley, …

Erosion Risks With High Stocking Rates At Kojonup Trial, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

A pasture grazing trial at Kojonup dramatically illustrated the effects of Cyclone Alby. Severe erosion was evident on the heavily stocked plots while the more lightly stocked plots showed little damage.

Agriculture And Pollution In Western Australia. Part 2. Pollution Problems In W.A, C V. Malcolm

Journal of the Department of Agriculture, Western Australia, Series 4

In Part I pollution was defined as a reduction in the usefulness of a resource and its significance in relation to resource fragility was discussed. Pollution problems in Western Australia are here considered in broad geographical regions with further subdivision into pollution types.

The Ord River Regeneration Project. 2. Dealing With The Problem, K Fitzgerald

Journal of the Department of Agriculture, Western Australia, Series 4

THE PROGRAMME of protective and remedial work being undertaken in the Ord River catchment area had as its major objective the re-establishment of perennial vegetation, as a means of controlling erosion and reducing the silt load of the rivers. It is now in its seventh year of operation.

The Ord River Regeneration Project. 3. Eight Years Of Progress, K Fitzgerald

Journal of the Department of Agriculture, Western Australia, Series 4

REGENERATION of degraded areas in regions of marginal rainfall is a slow process under the best of conditions, but on the Ord River Catchment, where much top-soil had been removed, the problem was unusually severe.

In many areas top-soil will have to be rebuilt before vegetation can be re-established.

This will be a long, slow process and regeneration will proceed through gradual plant succession from the "pioneer" annual species through to the permanent and more productive perennial species needed for a stable catchment area.

The Ord River Catchment Regeneration Project. 1. The Nature, Extent And Causes Of Erosion In The Ord River Catchment Area, K Fitzgerald

Journal of the Department of Agriculture, Western Australia, Series 4

OF the 17,800 square miles of Ord River catchment area, an estimated 1,450 square miles of country is subject to varying degrees of erosion.

This lies astride the Ord River and its major tributaries, the Elvire, Negri, Stirling, Panton, Turner, Nicholson and RB rivers.

The bulk of the eroded country lies in W.A. but part projects into the Northern Territory.