The journal news feed presents the editors’ condensed summaries of key findings from selected scientific papers from SNS’ two scientific journals Scandinavian Journal of Forest Research and Wood Material Science & Engineering.
Gain from birch mixtures on organic (but not mineral) soil
Silver birch outperforms downy birch in terms of growth, view but less strongly on organic than on mineral soils. Furthermore, downy birch has higher survival rates on organic soils. A long-term Finnish study addressed the possibility that mixtures could combine these advantages. The results indicate that pure silver birch is still the best alternative on mineral soils, but on peatlands a mixture could offer both the faster growth of silver birch and higher survival of downy birch.
Healthy seedlings harbour diverse fungal communities
Fungi on seedlings are mostly associated with problems, such as diseases. However, vast numbers of fungal colonies also thrive on healthy seedlings, and many of them may have neutral effects on plant growth or even promote it. Few studies have screened the full fungal community on seedlings. However, up to 55 different fungal taxa were detected on commercial spruce and pine seedlings in a recent Swedish study. Many of them were facultative pathogens, and could pose threats under certain conditions.
Raivola larch a safe choice for Finnish forests
Larches have a wide natural distribution in Russia. A longstanding question is which provenance(s) would perform best in Nordic conditions. Results of a field trial in southern Finland designed to compare the autumn phenology of 20 Russian provenances indicate that southern Dahurian provenances could be viable options, but may cease growth too late in the autumn. The safest alternative appears to be the well-known Raivola larch.
Minor damage from wild boar rooting
The silvicultural effects of the expanding wild boar populations in the Nordic countries have been debated, but very few studies have examined their true impact. A recent study has assessed the boars’ foraging behaviour and the damage they may cause to forests in a newly colonised area in southeastern Norway. The results indicate that the impact is very limited, although it can be visibly dramatic in patches where wild boars have rooted. Rooting was detected in less than 1% of the examined area, and the damage to roots was negligible.
Risky to import deciduous wood chips from North America
The global trade in living plants and wood poses great risks of spreading invasive insects from one continent to another. A Norwegian study has analysed threats from bark- and wood-boring insects that could follow imported deciduous wood chips from North America. The most potentially damaging species belong to the beetle genus Agrilus, including the emerald ash borer. The analysis indicates that European trees have not coevolved with these insects, and lack defences. If spread to northern Europe, these species may have considerable adverse economic and ecological consequences.