Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
1999
Del av bok/rapport – Damaging agents in European forest nurseries. Practical handbook
Isabella Børja
Forfattere
Isabella BørjaSammendrag
Practical handbook for identification of diseases and disorders in european forest nurseries. Many colour photos and illustrations.
Sammendrag
The Norwegian Monitoring Programme for Forest Damage has now been running for more than 10 years. Its main objective has been to monitor forest condition in relation to air pollution. Surveys of forests are performed on plots in a nation-wide representative grid network (Level 1 in the UN/ECE ICP Forests system), in a network of local county-wise plots, and in a network of intensively monitored plots (Level 2 in the UN/ECE ICP Forests system). Vitality indicators have shown a declining trend as reported earlier, expressed as reduced crown density and more of discoloured trees, particularly in spruce forests. However, results from last year have shown a slight improvement in tree crown condition. Tree mortality in excess of normal is not recorded. Forest condition generally depends upon soil, tree age, climate, pests and diseases, and other natural impact. The observed decreased crown density since 1989 is likely caused by a harsh climate, poor soil conditions and forest diseases. Air pollution loads, add to and interact with these factors. Most likely initiating factors are needed to produce visual symptoms. Summer drought is possibly such a factor of relevance to Norway. The actual effect of the air pollution component is therefore difficult to estimate; however, its importance is not excluded. In future, possible effects of a changed global climate should also be considered. Considering these results it is reasonable to presume that most Norwegian forest ecosystems generally are still in a satisfactory condition.
Forfattere
Kari Anne Sølvernes Øystein Johnsen Lars Sandved Dalen Gunnar OgnerSammendrag
Det er ikke registrert sammendrag
Forfattere
Tone GroeggenSammendrag
Forest Officers’ Monitoring Plots. Vitality survey 1999 In 1999 totally 648 plots were assessed comprising 42088 trees (Table 2). The plots are organised in clusters of four plots subjectively chosen in different cutting classes; III (young), IV (intermediate), V (old forest) and one in declining forest. For Norway spruce a reduction in crown density of 0,7% was observed last year. The largest reduction was observed for young stands (1,4%) (Fig. 2). As usual, crown density in the western part of the country was high (Fig. 3). In mid Norway the greatest reduction was observed in old stands whereas in eastern Norway the reduction was greatest in young stands (Table 3). For Scots pine the reduction in 1999 was 1,8%, and it was particularly high in young stands (3,7%). Only in old stands a small increase in crown density was observed. As in the case of Norway spruce the greatest reduction in crown density was observed in eastern Norway. In the western part of the country an increase in crown density was observed (Table 3). For Norway spruce the number of green trees in 1999 were reduced by 1,9%, a decrease which was consistent in all stands (Fig. 4, Table 4). For Scots pine the number of green trees increased in all stands but old stands. For Norway spruce the amount of cones was generally low in 1999 (Fig. 6 and 7). For some parts of northern Norway, the largest amount of cones was observed ever since establishment in 1988. The mortality rate was 0,2%. Infection of needle rust (Chrysomyxa abietis) in mid and northern Norway was less abundant in 1999 than in 1998 and 1997. There were a number of attacks of the fungus in eastern Norway. In 1999 results from Forest officers plots are not consistent with results from Level 1 plots. There was an increase in crown density and less discolouration of trees in level 1 plots. The monitoring of forest tree vitality is motivated by the concern for negative effects due to air pollution, and hence deserves to be given priority.
Forfattere
Svein SolbergSammendrag
Relationships within stands between growth and crown condition are presented. The data set contained about 25000 trees on 500 plots. Growth of single trees was determined by diameter measurements in 1991 and 1996. Diameter increments were recalculated to relative values in two steps; firstly relative to their stem diameter, and secondly relative to reference values for trees in the same plot, having no defoliation or no discoloration. These relative increment values, or growth indices, were distributed on a scale common for all plots, rendering them influenced neither by site and stand properties, nor by social status of each tree. The correlation between crown condition and growth, although of moderate strength, did validate crown condition assessments as a meaningful, but rough measure of forest health or vigour. The relationships were concave, and considerable growth depressions were already found at slight levels of defoliation and discoloration. Growth approached zero as defoliation and discoloration increased towards 100%. These relationships applied for all plots, regardless of their site productivity, development stage or regeneration method
Forfattere
B.J. Stocks M.E. Alexander B.M. Wotton R.A. LanovilleSammendrag
Det er ikke registrert sammendrag
Forfattere
Atle Hindar Erik Norgaard Petter Nilsen R. Høgberget Richard Frederic WrightSammendrag
Det er ikke registrert sammendrag
Forfattere
M. Kurm Ü. TammSammendrag
Det er ikke registrert sammendrag
Forfattere
Kari Anne Sølvernes Øystein Johnsen Gunnar OgnerSammendrag
The impact of elevated CO2 on height increment, phenology, biomass, and concentration of carbohydrates, pigments and elements in clones of Norway spruce (Picea abies (L.) Karst ) were studied in a three year open-top chamber experiment. The CO2-effect on height increment, biomass, and concentration elements of Silver birch (Betula pendula Roth.) was also recorded. The CO2 concentrations were ambient (380 µmol mol-1), approximately 500 and 700 µmol mol-1 CO2 in the chambers. Additionally, an outside control plot was present. Norway spruce were grown in intact profiles of forest soil and in fertilised peat. Silver birch was grown in forest soil only. Phenology and leader shoot extension were recorded regularly. Element concentrations of leaves and needles were analysed at the end of each growth season. At the end of the experiment, carbohydrate and pigment concentrations were also analysed. The impact of elevated CO2 on Silver birch and Norway spruce was small in this experiment. A marginal increase in biomass were recorded in Silver birch and in Norway spruce grown in fertilised peat. Phenology, concentration of elements, C:N ratio, concentrations of carbohydrates and pigments were almost unaffected by elevated CO2. The largest effect on growth and chemical composition were caused by chambers versus outside control plots and difference in nutrient supply (Norway spruce). Significant higher concentration of Al, Na and Fe were recorded in both species in the outside control plots compare to the plants inside the chambers. The increased concentration of these elements could be caused by a higher dust exposure outside the chambers than inside
Forfattere
Gunnar Jansson P.H. StåhlSammendrag
Det er ikke registrert sammendrag