The bitou bush ('Chrysanthemoides monilifera' subsp. 'rotundata' (DC.) T.Norl.) Threat Abatement Plan (TAP) aims to reduce the impacts of bitou bush on biodiversity in New South Wales. This is the first weed TAP in Australia and so its effectiveness in conserving threatened biodiversity, as well as its cost of implementation, must be examined to determine if this new approach should be adopted as a template for managing the biodiversity impacts of other major weed species. We therefore consider the question 'is the TAP a good investment in relation to protecting biodiversity'? We combine the costs of implementing the TAP with conservative, published estimates of the benefits of protecting biodiversity, to calculate the benefit-cost ratios of the investment. The ratios indicate that the benefits of the TAP exceed the costs under a wide range of economic conditions. While this result supports the approach, the cost of implementation should be analysed over the five years relative to the biodiversity outcomes in order to determine the ex post benefit of the TAP.

Special events play an important part in tourism and recreation choices in Australia, and many receive funding from various levels of government. However, the economic case for funding special events often focuses on estimates of expenditure, employment and indirect impacts rather than estimates of economic benefit or consumer surplus. The study discusses the application of the travel cost method for estimating consumer surplus associated with a special event. The event studied is the annual four-day 'Gemfest' in the sapphire fields of Central Queensland. Surveys were conducted in 1998 and 2002, and the derivations of the appropriate models, welfare calculations and comparisons over time are outlined.

A significant quantity of native vegetation and biodiversity remains on privately managed rangeland properties. Due to a lack of appropriate incentives, landholders do not always conserve these resources at a level that society desires. Regulations to conserve native vegetation can impose substantial costs on landholders. Market-Based Instruments have therefore been developed to provide market incentives aimed at achieving conservation at lower costs. We review the application of a Market-Based Instrument scheme, the West 2000 Plus Enterprise-Based Conservation program, which was designed for the Western Division of New South Wales. We estimate the private and social costs of increasing groundcover on privately managed properties, with and without the scheme. The costs are estimated under actual market and climatic conditions, and simulated under a wider range of conditions. The results indicate that costs vary widely across different conservation areas, depending on the location and previous management strategies of the property. The Enterprise-Based Conservation scheme has increased conservation in the region, and the implications from its application are reviewed to assist the further development of Market-Based Instruments.

This study is concerned with the economic assessment of programs to manage land degradation at a regional, farm and paddock level in New South Wales. It has been undertaken within an interdisciplinary framework by combining economic and environmental factors. The overall objective is to improve information for decision-making relating to the management of land degradation, through the integration of economic and bio-physical information. Despite increased funding support at Federal and State levels and a significant rise in the number of Landcare groups across Australia, land degradation continues to be a serious environmental problem. There is a lack of reliable information at various scales of management on the impact of land degradation on agricultural productivity, and the economic viability of land-management programs. Furthermore, few attempts have been made elsewhere to integrate economic and biophysical data to provide prescriptive information to improve management decisions. ... On the basis of the initial success of methods developed in this project, further research that incorporates economic and bio-physical information in models is recommended.

1. - Weeds have a wide variety of impacts on society, theenvironment and the economy. Some of the economicimpacts are benefits but most are costs.2. - The costs of particular weeds in given areas have beenestimated by many writers in a rich literature on theassessment of the impacts in agriculture. Only Combellack(1987) has attempted to estimate the nationwide impactof weeds in general.3. - In his innovative study, Combellack valued the economiccosts of weeds in 1981–82 to be $2,096m. New methodsof weed control and techniques of farm managementhave since been developed, and new weed species nowoccur. Therefore the current costs of impacts cannot bereadily compared with those of 1981–82.4. - The nationwide impact of weeds needs to bere-estimated to provide a more recent benchmark thatreflects current costs, prices and technologies, and thecurrent distribution of impacts within the community.A current estimate provides useful information fordecisions on the allocation of resources, cost sharing,and management of specific weed problems.5. - In this report, we attempt to estimate the economiccosts of weeds across Australia. In addition, we offer aneconomic framework to help consider the problems thatweeds create, and the generation and use of informationto resolve those problems.

Government funding to protect native plant communities is usually limited. For cost effectiveness, priority sites for conservation must therefore be identified and funds allocated to protect these sites according to the quantity of communities conserved per dollar of cost. In 1999, invasion of coastal vegetation in New South Wales (NSW) by bitou bush was listed as a key threatening process under the NSW 'Threatened Species Conservation Act' 1995. In accordance with the Act, a Threat Abatement Plan (TAP) was prepared to reduce the impacts of the weed to threatened biodiversity at priority sites. In the present study, data collected for the TAP were analysed by linear programming to determine the feasibility of achieving cost effectiveness in identifying sites and allocating funds, and to explore the impact of associated economic issues on the quantity of native plant communities that are protected. In addition to the total funds and costs per site, the quantity was influenced by alternative funding policies and different site selection strategies. Allocations that recognise these issues can enhance protection outcomes, and promote the cost effectiveness of weed management.

Valuation of the gains from protection of biodiversity is difficult because the services that provide the benefits do not normally pass through markets where prices can form. But the services sometimes pass through markets where consumers or producers behave in a market-oriented manner, and so the values implicit in this behaviour can be identified and derived. Estimates of the benefits of biodiversity protection are derived from the costs of protecting native plant communities from a major weed in Australia, by following this approach. In 1999, invasion of coastal areas of New South Wales by bitou bush (Chrysanthemoides monilifera subsp. rotundata (DC.) T. Norl.) was listed as a key process threatening native plants under the NSW Threatened Species Conservation Act 1995. In accordance with the Act, the Department of Environment and Climate Change prepared a Threat Abatement Plan (TAP) to reduce the impacts of bitou bush on biodiversity at each threatened site. The costs of protecting sites vary closely with the number of priority native species and communities at each site. Following standard economic assumptions about market transactions, these costs are interpreted to provide values the benefits of protecting extra species, communities, and sites. Key words: Bitou bush, Chrysanthemoides monilifera, threat abatement plan, valuation of biodiversity, benefit-cost analysis, weed control, defensive-expenditure method.

The NSW Bitou Bush Threat Abatement Plan (TAP) aims to reduce the impacts of bitou bush on biodiversity in New South Wales. This is the first weed TAP in Australia and so its effectiveness in conserving threatened biodiversity, as well as its cost of implementation, must be examined to determine if this new approach should be adopted as the template for managing the biodiversity impacts of other major weed species. We therefore consider the question "is the TAP a good investment in relation to protecting biodiversity?".

Environmental weeds are plants that invade natural ecosystems and present a serious threat to conservation of nature. Environmental weeds have been implicated in the extinction of several indigenous plant species, and they also threaten ecosystem stability and functional complexity. Historically, emphasis in weed control in Australian national parks has been placed on chemicals, manual pulling of small plants, excluding tourists and feral animal control measures. Recently, biological control has been introduced to control weed infestations. These methods typically have been applied as funds have become available, with little opportunity to consider their long-term effectiveness. As the threat from environmental weeds is becoming more fully recognised, an integrated, strategic, ecological and economic approach to weed management is needed. A deterministic dynamic programming model is developed for this purpose in this paper. A case study for scotch broom is presented, to assess the ways in which this approach can address the policy issues that face the community in the management of an environmental weed in a national park. The model takes account of the weed population dynamics, the effectiveness and cost of control measures, and the value of the park outputs (biodiversity, recreation and grazing). The dynamic programming model includes weed density and seed bank as state variables and a budget constraint for the control variables. The model is used to derive optimal control rules for any given state of the weed population. An optimal decision rule provides a package of control measures that can be used to attack the problem each year, depending on the current weed density and seed bank. Optimal trajectories are developed for a planning horizon of 45 years, and the effect of the budget constraint is analysed. The marginal value of an extra dollar for weed control, in terms of discounted future benefits, is estimated. It is shown that a combination of controls that targets both weed density and the seed bank is important. It is also shown (given the assumed parameters) that biological control is worth undertaking, as it appears as part of most of the optimal strategies identified. The paper concludes with policy recommendations for managing weeds in natural ecosystems.

When a weed invasion is first discovered a decision has to be made on whether to attempt to eradicate it, contain it or do nothing. Ideally, these decisions should be based on a complete benefit-cost analysis, but this is often not possible. A partial analysis, combining knowledge of the rate of spread, seedbank longevity, costs of control and techniques of economic analysis, can assist in making a good decision. This paper presents a decision model to determine when immediate eradication of a weed should be attempted, or more generally whether weed control should be attempted at all. The technique is based on identifying two 'switching points': the invasion size at which it is no longer optimal to attempt eradication but where containment may be an option; and the invasion size at which it becomes optimal to apply no form of control at all. The model is applied to a woody perennial weed in a natural environment. The results show that seedbank longevity is the main constraint on the maximum eradicable area and spread rate is the main constraint on the maximum containment area. Stochastic simulations are undertaken to derive probability distributions of costs which are than used to evaluate the effect of budget constraints on areas that can be eradicated. We find that, in the absence of a budget constraint, it may be desirable to eradicate invasions from areas as large as 8000 ha, but when budget constraints typical of those faced by agencies in Australia are introduced, feasible eradicable areas are less than 1000 ha.