Effect of breeding on income at first commercial thinning in silver birch plantations

Abstract

The economic importance of fast-growing tree species like silver birch (Betula pendula Roth.) is increasing due to growing demand for timber. Tree breeding provides the opportunity to increase the timber supply and thus ensure the most efficient use of forest land. Application of the results of a breeding program-the planting of young stands-is costly, and information on (potential) early income for the landowner from this investment is scarce. Therefore, the aim of this study was to characterize the gain from the use of improved silver birch material at the first commercial thinning. Material was collected from an open-pollinated progeny trial of 524 silver birch plus-trees at the age of 14 years in the central part of Latvia. Incomes from the first thinning were calculated at low and high timber prices. Heritability of growth traits (assessed as diameter at breast height) and timber value at first thinning were similar. Both timber market fluctuations and genetics had a notable impact on economic outcome: the internal rate of return for the selected best-performing families was 9.4% and 8.3% in the case of high and low timber prices, respectively; on average, for all families in the trial the figures were 8.1% and 6.7%, respectively. Results indicate profitability for investments in planting of improved regeneration material, even at a young age, in hemiboreal forests.