Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2018
Abstract
No abstract has been registered
Authors
Ryan BrightAbstract
No abstract has been registered
Authors
Ryan BrightAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Kjersti Holt HanssenAbstract
The production of ash from wood has greatly increased the last years, because biofuels are increasingly being used for heating and energy production. The ash may either be viewed as a waste problem, or as a resource. Wood ash has a liming effect and contains essential nutrients (P, K, Ca, Mg) which can be exploited for soil fertilisation. With enhanced knowledge about where and how wood ash addition may increase forest growth - without having negative effects on the environment - wood ash may become a renewable nutrient source. We studied the effect of fertilizing a Norway spruce (Picea abies) stand on relatively high site index in SE Norway with ash, nitrogen, or ash + nitrogen. After five years, both current annual increment and standing volume was best in the ASH + N treatment and least in the Control plots. The field trial should be followed for a longer period of time, as the ASH + N treatment still shows an increasing growth trend after five years.
Abstract
Several studies have shown the positive effect of nitrogen fertilization on conifer growth. In young Norway spruce (Picea abies) stands, an additional effect of including a mixture of other nutrients has often, but not always, been found. We studied effects of repeated fertilization in 28 stands with young Norway spruce in central Norway. The treatments consisted of plots without nutrient addition (Control), fertilization with 150 kg N ha−1 (150 N), and fertilization with 150 kg N plus addition of P, K, Mg, B, Mn and Cu (150 N + mix), repeated three times with approximately eight years interval. There was a clear positive effect on volume increment of the 150 N and 150 N + mix treatments compared to Control, and the effect was significantly higher for 150 N + mix than for 150 N. Fertilization had a stronger effect in the first fertilization period than in the second, while the third period was intermediate. The effect of 150 N + mix was strongest at plots > 300 m a.s.l. However, this correlation may be due to geological conditions rather than elevation. Further studies are needed to find out under which edaphic conditions a nutrient mixture will increase growth substantially in young spruce stands.
Abstract
No abstract has been registered
Authors
Kjersti Holt HanssenAbstract
No abstract has been registered
Abstract
Root rot in Norway spruce (Picea abies (L.) Karst.) causes substantial economic losses to the forestry sector. In this study, we developed a probability model for decay at breast height utilizing 18,141 increment cores sampled on temporary plots of the Norwegian National Forest Inventory. The final model showed a good fit to the data and retained significant relationships between decay and a suite of tree, stand and site variables, including diameter at breast height, stand age, altitude, growing season temperature sum (threshold 5°C), and vegetation type. By comparing model predictions with recorded decay at stump height in an independent data set, we estimated a proportionality function to adjust for the inherent underestimation of total rot that will be obtained by applying a probability model derived from increment cores sampled at breast height. We conclude that the developed model is appropriate for national and regional scenario analyses in Norway, and could also be useful as a tool for operational forestry planning. This would however require further testing on independent data, to assess how well the new model predicts decay at local scales.
Authors
Aksel GranhusAbstract
No abstract has been registered