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The purpose of the study was to create a near optimal environment for seedling establishment and growth, without the restrain of water and nutrients but under climate conditions typical for the region. This to give us valuable knowledge about the growth potential of different seedling types in the field. The experimental site was situated in southern Sweden. Six treatment combinations were applied including two site treatments; 1) soil inversion, i.e. the control treatment, and 2) soil inversion, drip irrigation and fertilization combined with plastic cover mulch, i.e. the optimization treatment, and three seedling types of Norway spruce (Picea abies L. Karst.), (a) a 2-year-old Plug+1 seedling, (b) a 1.5-year-old containerized seedling and (c) a 10-week-old mini seedling. Effects on seedling nutrient status and growth were studied during the first three years after planting. Height, diameter and biomass of the seedlings grown in the optimized environment were significantly greater than for seedlings grown in the control. The Plug+1 seedlings grown in the optimization treatment had, after three years, reached a height of 124 cm, while the containerized seedlings were 104 cm and the mini seedlings 45 cm. In practical plantations, this height is usually gained after 5â10 years depending on planting conditions. Biomass partitioning did not differ between optimization treatments, but between seedling types. The mini seedlings allocated less biomass to the roots and more biomass to needles and stem in comparison with the two other seedling types. Mini seedlings also broke bud earlier. Throughout the experimental period, seedling nutrient status for all treatment combinations was followed and a balanced nutrient supply of macro- and micronutrients was given in the optimization treatment. Nutrient concentrations were constantly higher in seedlings grown in the optimization treatment, but the difference decreased over time. Results from this study shows that, by improving site conditions associated with fast establishment, growth check can be avoided.

There is a great need to increase the production in Swedish forests to meet future demand from the forest industry and the bio-energy sector. One option to increase the production is to supply nutrients to young stands of Norway spruce. For the practical application it is important to develop and optimise fertilisation regimes in terms of production, economy and leaching of nutrients. The frequency of fertilisation is one important variable in the fertilisation regime, and this study aimed to study effects of different fertilisation frequencies on production and leaching of nitrogen. In 2001, five field experiments were established in southern, central and northern Sweden. Young stands of Norway spruce were fertilised every year, every second year and every third year. In addition, fertilisation with sludge pellets and wood-ash combined with nitrogen was investigated. The current annual increment after five years of treatment was significantly larger in fertilised than in unfertilised treatments. The difference in production between fertilisation every year and every second year was insignificant, while fertilisation every third year resulted in lower production. Sludge pellets and wood-ash fertilisation gave significantly lower production than fertilisation every second year even though approximately the same amount of nitrogen was applied. There was relatively little leaching of nitrate to ground water in all treatments; 0.6â1 kg N ha a from plots with fertilisation every year or every second year; and 2.7 kg N ha a from plots with fertilisation every third year. Most of the leaching was after the first fertilisation, in all treatments at all sites.â1â1â1â1

Under climate change, the importance of biomass resources is likely to increase and new approaches are needed to analyze future material and energy use of biomass globally and locally. Using Sweden as an example, we present an approach that combines global and national land-use and forest models to analyze impacts of climate change mitigation ambitions on forest management and harvesting in a specific country. National forest impact analyses in Sweden have traditionally focused on supply potential with little reference to international market developments. In this study, we use the global greenhouse gas concentration scenarios from the Intergovernmental Panel for Climate Change to estimate global biomass demand and assess potential implications on harvesting and biodiversity in Sweden. The results show that the short-term demand for wood is close to the full harvesting potential in Sweden in all scenarios. Under high bioenergy demand, harvest levels are projected to stay high over a longer time and particularly impact the harvest levels of pulpwood. The area of old forest in the managed landscape may decrease. This study highlights the importance of global scenarios when discussing national-level analysis and pinpoints trade-offs that policy making in Sweden may need to tackle in the near future. Key words: forest impact analysis, forest product demand, scenario analysis, Swedish National Forest Inventory (NFI), wood supply potential. Avec le changement climatique, l'importance des ressources en biomasse a des chances d'augmenter et de nouvelles approches sont necessaires pour analyser la matiere a venir et l'utilisation energetique de la biomasse localement et globalement. En prenant la Suede comme exemple, nous presentons une approche qui combine l'utilisation globale et nationale des terres ainsi que des modeles forestiers pour analyser les impacts des ambitions d'attenuation du changement climatique sur l'amenagement forestier et la recolte dans un pays en particulier. Les analyses d'impact de la foret nationale en Suede ont traditionnellement mis l'accent sur le potentiel d'approvisionnement en se preoccupant peu de l'evolution des marches international. Dans cette etude, nous utilisons les scenarios de concentration globale de gaz a effets de serre du Groupe d'experts intergouvernemental sur l'evolution du climat pour estimer la demande mondiale de biomasse et evaluer les implications potentielles sur la recolte et la biodiversite en Suede. Les resultats montrent que la demande de bois a court terme atteint presque le plein potentiel de recolte peu importe le scenario. En situation de forte demande de bioenergie, on prevoit que les niveaux de recolte vont demeurer eleves plus longtemps et vont surtout avoir un impact sur le niveau de recolte de bois a pate. Il est possible que les zones de vieille foret diminuent dans le paysage sous amenagement. Cette etude fait ressortir l'importance de scenarios globaux lorsqu'il est question d'analyse du niveau national de recolte et identifie les compromis auxquels les decisions politiques pourraient avoir a s'attaquer dans un proche avenir en Suede. [Traduit par la Redaction] Mots-cles : analyse des impacts sur la foret, demande de produits forestiers, analyse de scenarios, inventaire national des forets (INF) en Suede, offre potentielle de matiere ligneuse., Introduction Forests have an important role in climate change mitigation, both as a carbon sink and for production of renewable materials and energy (Intergovernmental Panel for Climate Change (IPCC) 2014b). [...]

Amyotrophic lateral sclerosis (ALS) is an adult-onset degeneration of motor neurons that is commonly caused by mutations in the gene encoding superoxide dismutase 1 (SOD1). Both patients and Tg mice expressing mutant human SOD1 (hSOD1) develop aggregates of unknown importance. In Tg mice, 2 different strains of hSOD1 aggregates (denoted A and B) can arise; however, the role of these aggregates in disease pathogenesis has not been fully characterized. Here, minute amounts of strain A and B hSOD1 aggregate seeds that were prepared by centrifugation through a density cushion were inoculated into lumbar spinal cords of 100-day-old mice carrying a human SOD1 Tg. Mice seeded with A or B aggregates developed premature signs of ALS and became terminally ill after approximately 100 days, which is 200 days earlier than for mice that had not been inoculated or were given a control preparation. Concomitantly, exponentially growing strain A and B hSOD1 aggregations propagated rostrally throughout the spinal cord and brainstem. The phenotypes provoked by the A and B strains differed regarding progression rates, distribution, end-stage aggregate levels, and histopathology. Together, our data indicate that the aggregate strains are prions that transmit a templated, spreading aggregation of hSOD1, resulting in a fatal ALS-like disease., Introduction Amyotrophic lateral sclerosis (ALS) is characterized by adult-onset degeneration of motor neurons. The resulting paresis begins focally, spreads contiguously, and causes death from respiratory failure when the breathing muscles [...]

Forest fertilization with nitrogen (N) has several benefits to society such as increased wood production and carbon sequestration. There are, however, concerns about N leakage, particularly following clear-cutting. The forest-floor vegetation may increase the N retention of forest ecosystems; however, very few studies have quantified the amount of vegetation required. We studied the relationship between vegetation cover and risk of N leakage, estimated by the amounts of ammonium-N and nitrate-N retained on ion-exchange capsules in the soil, during 4 years following the clear-cutting and harvesting of logging residues in a previously fertilized forest in southern Sweden. Previous fertilization increased the amount of nitrate-N captured on the capsules, whereas the amount of ammonium-N decreased. The vascular vegetation cover increased from almost zero to approximately 25% independent of fertilization. The amount of ammonium-N and nitrate-N retained on the capsules was already reduced by 50%-75% at 20% vegetation cover, and by 30%-40% cover, it approached zero, independent of the number of years since clear-cutting. The vegetation may impede tree-seedling establishment, implying a trade-off between seedling growth and N-retention capacity. However, our results indicate that maximum N retention may be achieved at a relatively low vegetation cover, which could be accomplished with less intrusive scarification methods than currently used. Key words: nutrient leakage, nitrogen, forest fertilization, ground vegetation, immobilization. La fertilisation forestiere avec de l'azote (N) procure de nombreux benefices a la societe, notamment une augmentation de la production de bois et de la sequestration de carbone. Cependant, le lessivage de N suscite des inquietudes, particulierement a la suite d'une coupe totale. La vegetation au sol peut augmenter la retention de N dans les ecosystemes forestiers, mais tres peu d'etudes ont evalue la quantite de vegetation necessaire pour y arriver. Nous avons etudie la relation entre la couverture de vegetation et le risque de lessivage de N; cette relation a ete estimee en fonction des quantites de N sous forme d'ammonium et de nitrate retenues sur des capsules d'echange ionique inserees dans le sol au cours des quatre annees suivant une coupe totale avec enlevement des residus de coupe dans des forets prealablement fertilisees du sud de la Suede. La fertilisation a augmente la quantite de nitrate captee par les capsules, alors que la quantite d'ammonium a decru. La couverture des plantes vasculaires est passee de pres de zero a environ 25% et ce, independamment de la fertilisation. Les quantites d'ammonium et de nitrate retenues sur les capsules ont ete reduites de 50%-75% avec une couverture de vegetation de 20%; lorsque la couverture atteignait 30%-40%, les quantites etaient presque nulles, independamment du temps ecoule depuis la coupe totale. La vegetation au sol peut nuire a l'etablissement des semis d'arbres, ce qui signifie qu'on doit faire un compromis entre la croissance des semis et la capacite de retention de N. Cependant, nos resultats indiquent qu'on peut obtenir une retention maximale de N avec une couverture de vegetation relativement faible, ce qui peut etre accompli par l'utilisation de methodes de scarifiage moins intrusives que les methodes courantes. [Traduit par la Redaction] Mots-cles : lessivage d'elements nutritifs, azote, fertilisation forestiere, vegetation au sol, immobilisation., Introduction The limitation of nutrient losses to ground and surface water is a prerequisite for the sustainable utilization of forest soils and the avoidance of eutrophication (Binkley et al. 1999). [...]