The Cost of Revegetation: Final Report

Abstract

In recent years an increasing number of revegetation projects have been undertaken throughout Australia. However, budget proposals developed using local costings for much of this revegetation work have often been assessed on an ad hoc, rather than systematic basis. Therefore there is a need to develop better benchmark estimates of the costs of revegetation across Australia. The Costs of Revegetation project surveyed Bushcare Support officers, commercial contractors, wholesalers and retailers to obtain information on the types of revegetation activities being undertaken, and the costs of those activities. From this data a set of benchmark costs (including ranges) have been developed for different elements of revegetation work. The benchmark costs are presented as groups that are based on the common elements of revegetation projects: • Project planning and management; • Transport costs; • Mechanical and chemical site preparation methods; • Fencing costs; • Seed and direct seeding costs; • Seedlings and seedling establishment costs; • Tree guard costs; and • Other costs less commonly incurred in revegetation work. Analysis of the costs of methods used at each of these stages showed several trends. Firstly, the costs of a revegetation project can vary significantly between regions. The differences depend dominantly on the revegetation methods used to achieve successful revegetation in different regions. Many combinations of methods can be used to achieve successful revegetation in different situations. The most costly components of revegetation projects are usually fencing materials, seedlings (in projects where seedlings are used) and labour (required for most projects). On some sites which have significant coverage of competing vegetation, the costs of spraying herbicides can be a significant proportion of total revegetation costs. Where tree guards are used they are also commonly a large proportion of total project costs, although not as much as seedlings and fencing. Several types of costs decrease on a per hectare basis as the size of the revegetation project increases. These include fencing, site preparation, line/boom spraying of herbicides and direct seeding, most of which can be attributed to a fixed cost per project for mobilisation and transport of equipment used. Other cost components, including seedlings, seed and tree guards are more likely to be independent of the size of the project, ie their cost per hectare does not change with project size except for bulk buying of components. In general large advance orders of seedlings and seed cost less per unit (eg per seedlings or per gram of seed) than small orders not made in advance. This indicates significant cost reductions can occur if large advance orders are made. For this to occur, project funding needs to be approved well in advance of the project being undertaken. THE COST OF REVEGETATION 4 It costs significantly more to revegetate areas in three of the six bioclimatic regions surveyed: the moist tropical regions, the central arid regions, and the warm moist temperate with hot summer regions. The increased cost is due primarily to the different methods used to successfully revegetate in these regions, rather than to differences in the cost of particular revegetation methods between regions. In more remote regions, the impact of transport costs for transporting materials and personnel to the site increases the costs of revegetation considerably. In general, direct seeding is a cheaper method of revegetation than establishing seedlings, while assisted natural regeneration costs less than either of the above methods. These results apply across all regions surveyed. However, there is little hard data on the relative success of the different methods in different regions and on different sites. Where seedlings are used, there is a shift to using 'speedlings', which are cheaper than traditional 50mm diameter tubestock. However, in some regions speedlings are not available. In addition, in many areas successful revegetation may require the use of more expensive advanced seedling stock, or the use of species which are not available as speedlings. The results of the survey show a need to conduct further study into the availability of materials used in revegetation projects in different regions, and the relative success of different methods of revegetation. Profiling available suppliers across regions would allow better identification of areas where more work is needed to develop supplies of the materials needed to effectively revegetate areas. Without a better understanding of the success of different methods, it is not possible to assess whether a method that is cheaper at the establishment phase is really the most cost effective revegetation method available. Show more