The current agricultural systems of broad areas of Australia are unsustainable, with large projected increases in salinization, decreases in water quality, wind erosion, and losses of biodiversity. It is well known that these problems can be partially resolved by farmland reforestation; however, a major issue is financing the scale of activity required. The international response to global warming, the United Nations Framework Convention on Climate Change and its Kyoto Protocol, includes provisions that enable greenhouse sinks (sequestration of carbon in soils and vegetation) to be used by parties to fulfil their obligations. The Kyoto Protocol also allows for trading in emission reductions, and this opens the possibility that investment in carbon sinks may help underwrite broader natural resource management objectives. This paper examines the possibilities for improved land management in Western Australia arising from the development of carbon sinks by considering: (a) the likelihood of a carbon market developing and the likely depth of that market as a result of current national and international policies, (b) the data available to provide estimates on different types of sinks, and (c) the likely benefits of wide-scale sink investment.It was estimated that the total amount of carbon that could be sequestered by reforesting 16.8 Mha of cleared farmland is 2200 Mt CO2 -e, and between 290 and 1170 Mt CO2-e by destocking 94.8 Mha of rangelands. There were insufficient data to produce estimates of sequestration following changes in tillage practice in cropping systems or the revegetation of already salinized land. We conclude that carbon sinks are only likely to become profitable as a broad-scale stand-alone enterprise when carbon prices reach AUD$15/t CO2-e, with this threshold value varying with carbon yield and project costs. Below this price, their value can be significant as an adjunct to reforestation schemes that are aimed at providing other products (wood, pulp, bioenergy) and land and water conservation benefits. Irrespective of this, carbon sinks provide an opportunity to both sequester carbon in a least-cost fashion and improve soil and watershed management. (c) 2006 Elsevier B.V. All rights reserved.

The current agricultural systems of broad areas of Australia are unsustainable, with large projected increases in salinisation, decreases in water quality and losses of biodiversity. Increased concentrations of greenhouse gases have been linked to global warming. The international response to this warming, the United Nations Framework Convention on Climate Change and its Kyoto Protocol, include provisions that enable greenhouse sinks, or the sequestration of carbon in soils and vegetation to be used by Parties as one strategy to fulfil their obligations. The Kyoto Protocol, which is yet to be ratified by Australia, also allows for trading in emission reductions, and this opens the possibility that investment in carbon sinks may help underwrite broader natural resource management objectives. This paper describes a study that examined the possibilities for improved land management in Western Australia arising from the development of carbon sinks. This considered (a) the likelihood of a carbon market developing and the likely depth of that market as a result of current national and international policies, (b) the data available to provide estimates on different types of sinks and (c) the likely benefits of wide-scale sink investment. The study was designed to quantify an upper limit to sink potential. It was estimated that the total amount of carbon that could be sequestered by revegetating 16.8 Mha of cleared farmland was 2.2 Gt CO2-e, and 3.3 Gt CO2-e by destocking 94.8 Mha of Western Australian rangelands. It was considered that there were insufficient data to produce estimates of sequestration following changes in tillage practice in cropping systems or the revegetation of already salinized land. We conclude that carbon sinks are only likely to become profitable as a broad-scale stand-alone enterprise when carbon prices reach A$15/t CO2-e. However, below this price their value can be significant as an adjunct to reforestation schemes that are aimed at providing other products (wood, pulp, bioenergy) and land and water conservation benefits. Irrespective of this, carbon sinks provide an opportunity to both sequester carbon in a least-cost fashion and improve soil and watershed management.

Gorse (Ulex europaeus) is the most feared scrub weed in New Zealand grazing land. This weed has infested 657 000 ha of New Zealand's pastures and past attempts at eradication of gorse from hill country have met with limited success. Traditionally, gorse has been controlled by chemical spray programs. Recent research has shown that the grazing by goats and sheep is a possible alternative for gorse control.

The development of a simulation model of an extensive pastoral farming system to assist analysts in their assessment of government policy measures is described. The model was designed to simulate, over a number of years, the physical and financial operation of a sheep and beef production system typically found in the North Island hill country of New Zealand. By manipulating model parameters and data related to prices, costs, taxation and credit, a range of policies can be represented and their effects simulated. The model is used to undertake an ex post analysis of the farm‐level impact of the supplementary minimum price scheme in New Zealand and to project farm performance following the abolition of the scheme. Consideration is given to the use of the model to represent sheep and beef production systems elsewhere.

Improved pasture technology for beef production provides the potential for significant increases in food production in many agriculturally underdeveloped regions of the world. However, if extension officers and farmers are to accept new pasture technology they must be convinced that it is superior to the traditional system, not only in terms of expected return but also in terms of its relative riskiness.

A stochastic simulation model designed to aid decision-making in Australia's campaign to eradicate bovine brucellosis is outlined. The model uses data related to district cattle numbers, disease prevalence and campaign intensity to project workload requirements, culling rates and campaign duration under alternative campaign strategies. Explicit account is taken of the uncertainty associated with initial disease prevalence and eradication procedures and provision is made for the updating of projections as actual campaign data become available. The application of the model is illustrated.