Genetically improved material has been proven to financially outperform unimproved material in timber production according to various studies. Genetic improvements in carbon sequestration are also promising, implying a possibility for further financial gains. Research Highlights: Including carbon pricing (i.e., timber production combined with carbon sequestration) with genetically improved material improves financial performance compared to pure timber production. Furthermore, the proportion of carbon benefit (%) of absolute bare land value fluctuates between 27% and 42%, indicating a substantial role of carbon sequestration to financial performance. Background and Objectives: Until now, economic analyses of the impact of tree improvement have mainly dealt with growth performance: volume yield or height growth. Yet planted forests can have a significant contribution to carbon sequestration, which will play a major role in carbon markets. This study focuses on comparing the financial performance between genetically improved and unimproved reforestation material when stand management is optimized according to timber production or to joint production (timber and carbon sequestration together). Another goal is to reveal possible differences in financial performance related to climatic conditions along the south–north gradient. Materials and Methods: The stand projections are based on simulations with and without genetic gains for joint production (timber + carbon) and merely timber production in eight locations in Finland. Stand-level optimization is applied for financial analyses. Results: Genetically improved reforestation material considerably enhanced financial performance when the joint production of timber and carbon was applied, regardless of the climatic region. Conclusions: If carbon pricing became a reality, there would be a distinctive shift in bare land values, which is further boosted by a genetic gain.

The summer drought of 2018 was one of the most climatically severe events in Europe that led to record-breaking temperatures and wildfires in many parts of Europe. The main objective of this study was to assess the impact of the 2018 drought on the phenotypic and genetic response of Norway spruce height growth using the Standardized Precipitation-Evapotranspiration Index (SPEI). To achieve this, the total cumulative height growth of about 6000 clones from 2016 to 2019 in four full-sib trials in Sweden, aged 6–7 years, and from 2017 to 2019 in two half-sib trials in Finland, aged 8–9 years, were measured. The results indicate that the 2018 drought caused reductions in the increment of trees. Although heritability estimates were similar to other reports for Norway spruce, the additive genetic variance was highly inflated in one of the visibly drought-damaged trials in Southern Sweden. Similarly, the genotype by environment (G × E) interaction was highly significant in the drought-damaged Southern Swedish trials. Both additive genetic and phenotypic correlations obtained between height increments in 2019 and final heights were the weakest in all studied trials, implying that the drought legacies might have influenced the recovery of trees in 2019. We may conclude that the severe drought can be an underlying factor for a strong G × E interaction and changes in the ranking of genotypes. Therefore, a selection of drought-resistant genotypes with a good growth capacity tested in variables sites should be considered as an important criterion for future breeding of Norway spruce.

Growth data from 15 progeny trials were analyzed to assess realized and expected genetic gains associated with improved Norway spruce (Picea abies Karst.) stock in southern Finland. The study materials included 257 seedlots originating from 9 wild stands and 17 seed orchards. The measurement data were collected between 22 and 30 years of age. First-generation seed orchard progenies showed a clear superiority over unimproved trees with a realized genetic gain of 8.4% in height growth, 9.0% in diameter growth, and 20.6% in stem volume growth. The respective genetic gains expected from 1.5-generation seed orchards were 12.8%, 13.5% and 36.9%. Stem slenderness and survival did not differ between groups of improved and unimproved trees. The interaction between genetic groups and sites was insignificant for all the traits, suggesting overall robustness of the gains across environments. The results do not include the additional genetic gain due to genetic thinnings and thus, they are likely to underestimate the currently realizing gains from genetically thinned first-generation seed orchards. The results are suggested to be primary information for further studies needed to model growth and yield of genetically improved Norway spruce stands over a full rotation.

We used a regression model approach to examine transferability of the 1.5-generation Swedish Scots pine orchard plus trees using the estimated coefficients of the transfer models recently developed for growth and survival of unimproved Scots pine in Sweden and Finland. Differences between observed and predicted values obtained for height and survival of 3214 plus tree progenies, tested at 58 progeny trials, were regressed on latitudinal transfers (∆LAT). In order to evaluate rates of improvement in height and survival of selected progenies over unimproved trees, average percentage differences in performances (∆g%) between the tree groups were calculated. Results indicate that the adopted models can further predict performances of more advanced-generation orchard trees, as there was no evidence of any systematic pattern in the slope of regression functions. Overall, ∆g% estimates obtained for height of progenies were greater than those of survival, suggesting Swedish Scots pine breeding activities are generating gain in the height growth. Moreover, ∆g% estimates obtained for height and survival of half-sib progenies were higher than those of full-sib ones, as a result of response to higher selection intensity applied in the reselection of their parents. This indicates that, in addition to the gain in growth, a gain in survival is also achievable from 1.5-generation seed orchards, depending on the intensity of selection and intended deployment site.