Cost-benefit analysis of tree improvement in Ireland.

Abstract

The use of genetically improved trees usually results in better returns due to one or more of the following responses: higher growth rates, better timber quality and higher rates of carbon sequestration. Tree improvement is expensive, so it is important that available scarce resources are spent wisely. To this end, cost-benefit analysis (CBA), using the net present value approach, was used in this study to assess tree improvement investment possibilities for a large number of species of potential interest to Irish forestry, assuming that a 15% gain could be achieved and the costs of improvement were similar for all species. The CBA results showed that the conifer species with the greatest potential were (in order): (1) Sitka spruce and Douglas fir; (2) hybrid larch and Norway spruce; (3) Scots pine; and (4) lodgepole pine. The ranking for the broadleaved species were: (1) Eucalyptus; (2) ash; (3) red oak and sycamore. When issues such as availability of material from other programmes abroad, biological constraints (e.g. disease vulnerability, breeding and propagation problems), and the potential usage of species in a planting programme are also considered, the establishment of new breeding programmes are difficult to justify for most species, with the exception of Sitka spruce. The best approach for most species is to establish seed stands or seed orchards (with untested, or if available, tested material) to provide material for planting, but for some species it may also be possible to secure material from improvement programmes abroad.