The journal news feed presents key findings from selected scientific articles from SNS’ scientific journal Scandinavian Journal of Forest Research. The summaries are personal interpretations of the content made by the editor of News & Views.
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Fungal attacks on Norway spruce can be hampered by genetic selection
Two pathogenic fungi are major threats to conifers: Heterobasidion parviporum causes root rot and Ceratocystis polonica causes blue stain in Norway spruce, stomach resulting in serious losses for the forest industry. A genetic study in a seed orchard in Norway shows that there is a genetic component in susceptibility to attacks by both of these fungi. No families seem to be totally resistant, but genetic selection for susceptibility has the potential to reduce the damage caused.
Read more in: Skrøppa, T. et al. 2015. Variation in phloem resistance of Norway spruce clones and families to Heterobasidion parviporum and Ceratocystis polonica and its relationship to phenology and growth traits. Scand J For Res 30(2), 103-111.
Spruce material could be more widely used than recommended today
The adaptation of regeneration material to different sites can be traced via genotype by environment interactions. A large interaction suggests specific selection of genotypes for a given site. In this context, a large number of field trials with Norway spruce in southern Sweden have been analysed. The results show that the interaction is generally low to moderate with respect to growth traits, and largely unpredictable with respect to geographic and climatic variables. One major implication of the study is that the same genetic material of Norway spruce can be used over large areas in southern Sweden without major losses in genetic gain. However, frost-prone sites still require special attention through the use of more frost tolerant genotypes.
More robust biomass estimates for introduced conifers
Volumes, biomass production and carbon sequestration estimates require well-performing functions validated in the field. When new species are introduced, functions must be adjusted to the specific species and local conditions. This Danish study produced functions for five exotic conifers: grand fir, silver fir, Douglas-fir, Sitka spruce and larch. The overall models explained 98% of the variation in diameter and height, 66% in stem basic density and 86% in the biomass expansion factor.
Concern for threatened species has driven current conservation-oriented forestry in Sweden
Retention forestry, where conservation of biodiversity is integrated with timber production, has become standard in the Nordic forest sector today. But how did it arise? For this article, Per Simonsson and his colleagues dug through historical articles to elucidate the development from the vigorous debates and conflicts in the 1970s to the current situation where both market and regulations have paved the way for retention forestry. The authors identify six major driving forces for this progression, the main one being concern about threatened species.
Stump treatment of young spruces can reduce root rot infection
If pre-commercial thinning is performed in summer without stump treatment, there is a great risk that root rot will infect the stumps and impair the quality of the remaining stand. Treating the stumps of young trees, aged 20 years, can reduce infection, but new application methods must be developed to economically justify treatment of such small trees. This paper presents a simulation based on the root disease model RotStand, and the results still need to be validated in field.
Read more in: Wang, L. 2015. Simulated Heterobasidion disease development in Picea abies stands following precommercial thinning and the economic justification for control measures. Scand J For Res 30(2), 174-185.