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.
2006
Authors
Anne-Kristin Løes Johanne E. SchjøthAbstract
The manuscript is a part of a report on Eruopean research in organic food and farming, published by the ERA net CORE Organic in 2006. 11 European countries which have had significant research programmes in organic food and farming have contributed to the report. For each country, the history and organisiation of this type of research is described, as well as details about completed and on-going research programmes and their funding, research facilities, research strategies and scientific education within organic food and farming.
Authors
Ken Olaf StoraunetAbstract
In recent years attention has focused on the consequences of modern forestry on biological diversity. Additionally, past forest management has reduced the structural heterogeneity of forest landscapes, increasing the interest in assessing forest naturalness. General forest history of Norway shows that single-tree and selective logging was the main silvicultural method up to the mid-twentieth century when clearcutting practice took over as the dominating logging regime. Thus, regenerating forests on former clearcut areas have barely reached the stages of maturity, implying that mature forests of today for the most part are remnants from the period of selective logging. This thesis has been part of a comprehensive research project where one of the general objectives was to gain knowledge on the distribution and abundance of rare and threatened species in Norwegian forests....
Abstract
The root-rot causing fungus Heterobasidion annosum can attack both spruce and pine trees and is the economically most damaging pathogen in northern European forestry. We have monitored the H. annosum S-type (fairly recently named H. parviporum) colonization rate and expression of host chitinases and other host transcripts in Norway spruce material with differing resistances using quatitative realtime PCR. Transcript levels of three chitinases, representing classes I, II and IV, were monitored. Ramets of two 33-year-old clones differing in resistance were employed as host material and inoculation and wounding was performed. clones in the area immediately adjacent to inoculation. Fourteen days after infection, pathogen colonization was restricted to the area immediately adjacent to the site of inoculation for the strong clone (589), but had progressed further into the host tissue in the weak clone (409). Transcript levels of the class II and IV chitinases increased following wounding or inoculation, while the transcript level of the class I chitinase declined following these treatments. Transcript levels of the class II and class IV chitinases were higher in areas immediately adjacent to the inoculation site in 589 than in similar sites in 409 three days after inoculation, suggesting that the clones differ in the rate of pathogen perception and host defense signal transduction. This an earlier experiments using mature spruce clones as substrate indicate that it is the speed of the host response and not maximum amplitude of the host response that is the most crucial component in an efficient defense in Norway spruce toward pathogenic fungi such as H. annosum.
Authors
Tor Gunnar Vågen Masy-A A Andrianorofanomezana Salmata AndrianorofanomezanaAbstract
Soils of tropical forests are often inherently nutrient poor, although the extents of extremely infertile tropical forest soils are not as large as previous estimates may suggest. This paper presents findings from a study of change in soil quality in relation to deforestation and land use change in the highlands of Madagascar. A synthesis of some of the available research results related to soil characteristics of tropical forest, and their response to disturbance and conversion (i.e. deforestation) is made. The study was conducted in an area in the eastern highlands of Madagascar. The predominant soil types in the eastern highlands of Madagascar are Oxisols, which are acid and have a high content of low activity clays. The chemical characteristics of forest soils were found to be highly variable, with soil organic carbon (SOC) and total nitrogen (TN) contents ranging from 22.8 to 120.8 and 2.2 to 8.8 g kg(-1), respectively. Conversion of forest to cropland (tavy) reduced SOC contents by 23.8 g kg(-1) in the first year after clearing and by 11.3 g kg(-1) year(-1) on average in the first 3 years of cultivation. Mixed fallow systems recovered SOC at rates of about 6.5 g kg(-1) year(-1). Available phosphorus (P) and exchangeable base cations (Ca, Mg and K) increased after clearing as a result of biomass burning while cation exchange capacity is largely determined by SOC content and follows similar trends as SOC after clearing. The long term trend was, however, in the direction of significant decreases in available P while the sum of base cations showed little change relative to natural forest soils. (C) 2005 Elsevier B.V. All rights reserved.
Authors
K Kausrud Atle Mysterud Y Rekdal Ø. Holand Gunnar AustrheimAbstract
No abstract has been registered
Abstract
Resins and oils can easily evaporate during drying processes at high temperatures. The aim of this research was to investigate different drying methods such as oven-drying, vacuumdrying and freeze-drying of resin modified pine-sapwood samples to determine wood moisture content (MC) and weight percent gain (WPG). The results showed that freeze-drying is the slowest process. Vacuum drying of water impregnated samples takes approx. 7 times longer compared to oven-drying. The initial moisture content of wood before impregnation used in this research has only little influence on the WPG.
Authors
Andreas TreuAbstract
No abstract has been registered
Authors
Joha W. Grobbelaar Michael J. Wingfield P. Bloomer Halvor Solheim Brenda D. WingfieldAbstract
No abstract has been registered
Authors
Seppo NevalainenAbstract
No abstract has been registered
Abstract
Conventional farmers converting to organics have contributed to most of the rapid expansion of organic farming in recent years. The new organic farmers may differ from their more established colleagues, which may have implications for the development of the organic farming sector and its distinctiveness vis-a-vis conventional production and marketing practices. The aim of this study was to explore Norwegian organic dairy farmers' personal and farm production characteristics, farming goals, conversion motives, and attitudes to organic farming, grouped by year of conversion (three groups). A postal survey was undertaken among organic dairy farmers (n=161). The results show that the newcomers (converted in 2000 or later) were less educated than the early entrants (the so-called 'old guard') who converted in 1995 or earlier. The frequency of activities like vegetable growing and poultry farming among the old guard was high. The late-entry organic herds were fed with more concentrates and had a higher milk production intensity, showed a higher incidence of veterinary treatments and less frequent use of alternative medicine than the herds of the two earlier converting groups. For all groups of farmers, the highest ranked farming goals were sustainable and environment-friendly farming and the production of high-quality food. Late entrants more often mentioned goals related to profit and leisure time. On average, the most frequently mentioned motives for conversion were food quality and professional challenges. The old guard was more strongly motivated by food quality and soil fertility/pollution issues than the others, whereas financial reasons (organic payments included) were relatively more important among the newcomers. All groups held very favorable views about the environmental qualities of organic farming methods, albeit with different strengths of beliefs. Even though trends towards more pragmatic and business-oriented farming were found, the majority of the newcomers were fairly committed.