Australian Natural Resources Atlas

Natural Resource Topics

Landuse Change, Productivity & Development - Introduction

Final Report of Theme 5.1 to the National Land & Water Resources Audit
August 2001

1. Introduction

1.1 Context

The National Land and Water Resources Audit aims to provide nation-wide assessments of Australia's land, vegetation, and water resources to support sustainable development now and in the future. Theme 5 (Productivity and Sustainability) addresses the first objective of the Audit, "to provide a clear understanding of the status of, and changes in, the nation's land (including vegetation) and water resources and implications for their sustainable use". Addressing the implications for sustainable use, this project answers two questions from the Strategic Plan:

There are other influences underpinning this work. There is Agenda 21 of the 1992 Rio Earth Summit where Chapter 10, which is on 'Integrated Approach to the Planning and Management of Land Resources', calls on governments to ensure that policies and policy instruments support the best possible land use and sustainable management of land resources. The Land Use and Land Cover Change Program (LUCC) in 1996 by the IGBP and IHDP notes that land use/cover is a basic element of a wide range of environmental issues. There is also the Strategy for Ecologically Sustainable Development (ESD) objective 13.1 dealing with environmental and economic land use decision making (Council of Australian Governments 1992). Under that objective governments will "continue efforts to improve levels of understanding of Australia's natural resource base, and work towards land-use planning and decision-making processes which take those resource values into account").

1.2 Land use

Land is a major resource used by agriculture to provide products that service human needs and wants. These needs and wants include: nutritious food such as meats, milk, eggs, grains, vegetables and fruit; fibres for clothing and furnishings; and industrial products like oils, leather, starches and building materials. The actions undertaken in using the resource have impacts on the condition of land, vegetation and water resources and this is the focus for the National Land and Water Resources Audit (the Audit).

As a framework to present information at a range of scales the diagram of the land use pyramid in Figure 1-1 uses a hierarchy of categories. The pyramid represents a series of aggregations, such that each level of activity operates at a larger scale and over a longer time frame and should capture all those of the level below. However, there may easily be changes in one level, such as land use practice, that does not show at the land use level. But it would have a strong influence on the operations at the level below, eg individual action.

At the top of the pyramid aggregation to industries (e.g. sugar cane, wheat and dairying) and land use (e.g. cropping, irrigation), allows a wider picture to be presented at State and national level. Each land use encompasses many land use practices. For example, broadacre cropping includes the operation of weed control by some of the practices of cultivation, crop rotation, residue burning, or herbicides. However, these practices vary across a landscape and from region to region and are difficult to collect. The Audit's "Benchmarking Practice in Australia's Agricultural Industries" project (Project 5.2) reports on environmental challenges and impacts of land use facing Australia's agricultural industries and how industry is responding to these challenges.

Many individual actions or tasks, such as spraying with a herbicide, cultivation and burning, make up a land use practice such as weed control. These actions vary considerably in space and time and are both too numerous and too small to monitor and calculate. It is more convenient for producing an overall picture to represent them as belonging to larger categories.

Figure 1.1 Diagram of hierarchy in time and area scales of categories of land management and their effect on land condition
Figure 1.1 Diagram of hierarchy in time and area scales of categories of land management and their effect on land condition

At the base of the pyramid the condition of land, vegetation and water resources is the cumulative consequence of many individual actions. At the interface of action and land condition is land cover, usually as vegetation but roads and buildings also have a local influence on land condition (O'Callaghan 1996). Land use change can result in whole cover changes from one type to another or in changes in the intensity of land use. For instance, the move to earlier sowing of wheat in Western Australia does not show up as a change of land use, but more as an intensity of land use practice. It will influence land and water condition through longer period of vegetation cover by the crop, which then increases the efficiency of water use and reduces the amount of water entering the groundwater system - which in turn may provide benefits for areas at risk from dryland salinity.

Consequently, where land use and its practices that are contributing to declining land condition, then the most obvious solution is to change land uses and practices to more appropriate ones. To do this effectively we should first understand what and where land uses are now, and if and where trends and directions in land use are changing. Then it may be possible to make projections for the future. We should expect that changing of land uses is a complex phenomenon that will differ greatly from place to place.

The principal focus of environmental decision-making as it affects agriculture is on agriculture's use of natural resources. The emphasis is on on-farm resources such as soil (erosion, acidification), associated biota (feral pests, weeds, ecosystem functions) and supply of irrigation water (Godden 1997). While there are wider issues, such as its affects on biodiversity and as source and sink for greenhouse gases, where these externalities lie beyond farms they are not included in this report.

1.3 Agricultural land use

The estimated total area of business establishments used for agriculture is about 464 million hectares, which represents around 60% of the total land area of Australia (ABS 1997). This use of land supported 240 000 farmers and 397 000 employees in 1996 and contributed more than $27 billion to the gross domestic product, including $20 billion from export income. Broadacre crops, including cereals (except rice), pulses and oilseeds, appear as a dominant category in 1996-97 (Figure 1-2) and indeed constituted nearly 30% of the total value of agricultural production (Table 1-1). The leading producers by value were New South Wales and Western Australia. Horticulture (including vegetables, fruit and grapes but not potatoes) which was a major contributor at 15% of total value of agriculture was more evenly distributed between Victoria, Queensland, New South Wales and South Australia. The semi-intensive crops of rice, cotton, potatoes and sugar cane were largely produced in Queensland and New South Wales. Sheep products of wool and meat had declined in importance to 13% of total value of production and were principally produced in New South Wales, Victoria and Western Australia. Milk is becoming a major commodity value at 10% of total agricultural value, predominantly in Victoria. Queensland, with New South Wales and Victoria, produces most of the beef slaughterings, which contributes 12% to the total value of agricultural production in Australia.

Commodities that contributed more than $1 billion in 1996-97 value were (Table 1-1) vegetables, fruit, cane sugar, cotton lint, wheat, wool, sheep meat, milk and beef. Some lesser known commodities of significance included rice, potatoes, hay, the oilseeds (canola and cottonseed), and the pulses (particularly lupins). Overall New South Wales contributed nearly 30% to the total value of agriculture, followed by Victoria, Queensland, Western Australia, South Australia and Tasmania.

Figure 1.2 Value of products from agricultural land use categories in the States of Australia in 1996-97. (source ABS)
Figure 1.2 Value of products from agricultural land use categories in the States of Australia in 1996-97. (source ABS)

In addition, there are considerable exports of transformed agricultural products of about $6.2 billion dollars in 1996-97. They included $1.8 billion of dairy products (butter, cheese, milk powders etc), $0.8 billion in beverages (mostly wine, but also beer, spirits and soft drinks), $0.7 billion in flour and bakery products and $0.7 billion in canned or frozen fruit and vegetables.

Because of this importance of agricultural land use to the national economy, the emphasis in this project is on the areas of more intensive agriculture of Australia and how rural industries and systems of land use have changed over the past 20 years. It seeks to identify spatially within rainfed and irrigated regions the magnitude, scale and intensity of shifts in land use, productivity and enterprise diversification that have occurred in areas of intensive agriculture over the past 20 years, and to also generate medium term projections for future change.

This report provides

Table 1.1 Value of major products from agricultural land uses grouped according to intensification , with distribution across the States of Australia in 1996-97. (source ABS)
Commodity & group Value ($A mill) % of Total Agric % Exported Distribution by State (percentage)
NSW Vic Qld SA WA Tas
Horticulture 4 243 15.1 13 21 26 24 16 9 3
- Vegetables 1 213 4.3 15 13 27 33 10 11 6
- Fruit 2 389 8.5 24 26 19 22 6 3
- orchard 1 668 5.9 22 25 24 26 14 7 4
- grapes 721 2.6 17 22 30 2 41 4
Semi-intensive 3 289 11.7 41 4 47 4 1 2
- Sugar 1 186 4.2 79 6 94
- Cotton 1 342 4.8 80 70 30
- Rice 310 1.1 57 99 1
- Potatoes 449 1.6 <1 11 27 12 26 8 16
Broadacre crops 8 383 29.8 76 32 14 10 15 29 1
- Cereals 7 177 25.5 76 36 11 10 14 28
- wheat 4 878 17.3 81 36 10 9 12 33
- Oilseeds 325 1.2 45 51 17 13 7 13
- Pulses 594 2.1 69 8 25 4 17 47
- Hay (incl pastures) 596 2.1 20 35 9 16 5
Livestock products 5 754 20.4 28 37 10 8 13 4
- Wool 2 621 9.3 83 38 20 7 11 22 3
- Milk 2 809 10.0 18 55 12 6 6 5
Livestock slaughters 6 215 22.1 53 28 23 26 7 11 2
- Lamb & mutton 1 039 3.7 70 24 33 5 13 23 2
- Beef & veal 3 390 12.0 74 23 20 36 4 8 2
Total Agriculture 28 156 100 29 22 20 10 15 2

1.4 Scale effects in determining change

Each form of land degradation has its own timetable and scale of action. For instance within farms traffic pans can form in 1-5 years, loss of surface structure in 2-10 years, decline of soil organic matter to two thirds of original in 5-20 years and drop in pH by one unit in 7-30 years (from Hamblin 1991). Off-farm, substantial salinity and water quality impacts can occur over a wide range of times from a few months (for pesticide residues in water) to decades (for dryland salinity) or even longer (for greenhouse gas emissions).

For effective management of each form land degradation action and information is required at its appropriate scale (Williams and Walcott 1998). The information available to this project was mostly at the shire scale (the smallest scale that the Australian Bureau of Statistics provides data is at the Statistical Local Area). This is considerably larger than a single farm (an SLA typically has about 250 farms but may range from 40 to 800) but generally smaller than a catchment or a region. Therefore some impacts at this scale may become lost in the aggregation process. Likewise a time-step of one year within a 15 year period may not capture the full impact eg pH, salinity development. The case studies included here illustrate that some effects show up most effectively at sub-SLA level. To capture these effectively will involve geo-location of statistics depending upon who wants to know.

All actions will have unintended consequences as well as those intended. It is the aim of planning, modelling and monitoring to reduce those unintended consequences and to be able to respond appropriately. Scale becomes an important consideration in interpreting the signals, particularly when there is a lot of noise or variation in the signal.