An economic evaluation of alternative genetic improvement strategies for farm woodland trees

A cost-benefit analysis (CBA), focusing on the Net Present Value(NPV) of a current genetic improvement programme for broadleavedtrees was performed using Monte Carlo simulation, with an add-onsoftware package (‘@RISK’) specifically designedto take account of the uncertainty associated with long-termprojects. The CBA was undertaken by evaluating the total costof achieving a given estimated genetic gain via each of thebreeding strategies considered. The estimated values of geneticgain were then expressed in terms of the increased value oftimber output. Cash flows were based on current estimated treeestablishment costs and anticipated productivity of the fourtree species included in the programme (ash, Fraxinus excelsior;sycamore, Acer pseudoplatanus; wild cherry, Prunus avium; andsweet chestnut, Castanea sativa), when grown primarily for atimber crop. The results of the NPV analysis indicated thattree improvement could be cost-effective for small genetic gains,but that current breeding strategies differed markedly in theircost-effectiveness. Improvement scenarios based on conventionalselection and testing techniques, such as simple mass selectionand recurrent selection (seed orchards), were found to be themost cost-effective at a discount rate of 6 per cent. In contrast,tree improvement scenarios based on clonal techniques consistentlyranked lowest, despite the much higher genetic gains achieved.The use of clonal techniques was found to be particularly hardto justify with broadleaved tree species of relatively low timbervalue. Overall, with the current state of broadleaved timbermarkets in the UK, and the current areas being planted, investmentin basic genetic improvement of high-value timber species appearsfinancially worth while. The estimated direct additional financialbenefit to growers, if new planting is undertaken with improvedstock as opposed to unimproved stock, is estimated to rangefrom £38 ha^–1 with Simple Mass Selection to £100ha^–1 with Simple Recurrent Selection.