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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.

2007

Sammendrag

Urbanization and an increasingly globalized food system cause growing physical and psychological distances between producers and customers. Alternative distribution initiatives with direct sale to local customers are emerging. This paper reports results of two surveys, one from producers and one from customers, in the newly introduced Norwegian farmers market system. The main aim of the research was to examine attitudes toward local foods and evaluate the potential of this new marketing channel to reduce the distances between farmers and consumers. Results show that producers were more concerned than customers regarding knowledge on how food was produced, and locally marketed, although customers were also interested in these issues. Both groups regarded as to how food was produced to be more important than where it was produced. Producers were more interested in giving customers information on agriculture than customers were in receiving this information. The attitudes toward food differed between respondents of larger urban cities and smaller cities in Norway. Producers traveled a longer distance (average 79 km) than customers (average 14 km) to come to the markets, but traveling distance differed substantially among the sites owing to market location, number of local farmers and small-scale local processors, and product diversity. Results suggest that the farmers markets have potential to reduce both physical and social distances between producers and consumers, and thereby contribute to the sustainability of local food production. Understanding farmer and consumer attitudes can contribute to organization and promotion of farmers markets in Norway and elsewhere. doi:10.1300/J064v30n04_06.

Sammendrag

The substitution of fossil fuels by biomass in energy consumption is a measure to decrease the emission of greenhouse gases and thereby mitigate global warming. An increased use of wood-based biomass for energy can also, if well managed, enhance the socioeconomic benefits from forests, particularly for small forest owners substituting purchased energy resources with their own wood fuels. At both European and national levels, political plans exist for an increased use of forest biomass for energy. However, the potential negative impact on the forest ecosystem and the surrounding environment due to an increased utilisation of wood-based biomass for energy needs also to be considered. The increased use of wood-based biomass must be fully in accordance with the principles of sustainable forest management, for example as outlined by the pan-European Ministerial Conference on the Protection of Forests in Europe.

Sammendrag

The relationships between measures of forest structure as derived from airborne laser scanner data and the variation in quantity of young trees established by natural regeneration in a size-diverse spruce forest were analyzed. A regeneration success rate (RSR) was regressed against 27 different laser-derived explanatory variables. The 27 different models were ranked according to their Akaike information criterion score. Each laser variable was then associated with two categories. These were return and type. Within the return and type categories, the variables were grouped according to if they originated from first or last return echoes and if they were canopy height or canopy density metrics. The results show that the laser variables strongest correlated to the quantity of small trees could be attributed to last return and density metrics.

Sammendrag

Many demand and supply-side policies impede or foster forestry entrepreneurship. A study was conducted to consolidate existing knowledge on policies influencing forestry entrepreneurship in Finland, Norway, Japan, Australia, the Philippines and the USA, and to draw conclusions on these impeding and fostering factors. From the country studies it was difficult to find common structures on policies affecting forestry entrepreneurship. This is understandable because most policies in forestry are aimed at supporting sustainable forest management, wood production and ecological services of the forests rather than entrepreneurship as such. Despite the high variety of policies applied in the study countries, it can be concluded that strict public control on forests? use and management potentially impedes forestry entrepreneurship. While these policies assist to correct market failure and to promote sustainability of forest management, they may also result into unnecessary and ineffective regulations that limit the opportunities for forestry entrepreneurship. A common feature promoting the demand for forestry entrepreneurship in some of the countries studied is the strong emphasis on forestry cooperatives, which were important institutions to support small-scale forestry entrepreneurship. In many study countries, different ad hoc programs are implemented to find new economic and entrepreneurial opportunities aside from the current use of wood and forests. Subsidies and tax incentives are commonly applied to reduce risks from making forestry investments or otherwise increase the economic return from timber production.

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Sammendrag

In Norway, as in many other European countries, income from forestry has become marginal to owners? household economies and most employment of forest-owner households is now undertaken off the property. Also, many forest owners have focused increasingly on other revenue-earning activities on their properties, such as providing recreational services. It is a challenge in all kinds of production to find the optimal way of converting inputs into outputs, i.e., to be technically efficient. Extent of financial dependency on income from forestry differs between part-time and full-time forest owners. Since the two groups have different livelihood strategies, it is plausible that full-time forest owners have more professional forest management practices. Data for a cross-section of 3,249 active (i.e., harvesting) forest owners were extracted from the 2004 Sample Survey of Agriculture and Forestry representing the year 2003. A stochastic production frontier analysis was applied to evaluate forest management efficiency impacts of important factors including property and owner characteristics, outfield-related and agricultural activities, off-property income and geographical location in central or remote areas. It was found that many forest owners are technically inefficient, and there exist opportunities for improved performance. Off-property income was found to have an estimated negative impact on technical efficiency, the inefficiency arising (weakly) with increasing share of household incomes from outfield activities, and properties in urban centred areas are less efficient than those in remote areas. One policy implication of the study is that a potentially substantial efficiency increase might be achieved from allowing small inefficient woodlots to merge into larger units of forestry production. Also, providing support for forest management plans may improve efficiency.

Sammendrag

Mechanistic, multi-compartment decomposition models require that carbon (C) and nitrogen (N) in plant material be distributed among pools of different degradability. For this purpose, measured concentrations of C and N in fractions obtained through stepwise chemical digestion (SCD) and values predicted from near-infrared (NIR) spectra or total plant N concentration were compared. Seventysix cash, forage, green manure and cover crop plant materials representing a wide range in biological origin and chemical quality were incubated in a sandy soil at 15 degrees C and -10 kPa water potential for 217 d. A mechanistic decomposition model was calibrated with data from soil without plant material and initialised by data on amounts of C and N in fractions obtained from SCD directly or C and N in SCD fractions as predicted from NIR spectroscopy or plant N concentration. All model parameters describing C and N flows from plant material were kept at default values as defined in previous, independent works with the same model. When results from SCD were used directly to initialise the decomposition model, C and N mineralisation dynamics were predicted well (r(2) = 0.76 and 0.70 for C mineralisation rates and accumulation of inorganic N, respectively). When a NIR calibration was used to predict the SCD data, this resulted in nearly equally good model performance (r(2) = 0.76 and 0.69 for C and N mineralisation, respectively). This was also the case when SCD data were predicted from plant material N concentration (r(2) = 0.76 and 0.69 for C and N). We conclude that the combined use of a mechanistic decomposition model and quality data from SCD is a highly adequate basis for an a priori description of the mineralisation of both C and N from common agricultural plant materials, and that both NIR spectroscopy and measurement of total N concentration offer good and cost-effective alternatives if they are calibrated with SCD data. (C) 2007 Elsevier Ltd. All rights reserved.

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Sammendrag

This paper presents the potential of composting oil wet drill cuttings as a drilling waste disposal option. The potential is substantiated by results from several laboratory and field experiments. Artificially oil wetted drill cuttings were prepared by adding commonly used base oils from Norwegian offshore operations to a representative clay. Degradation of the hydrocarbon components in the oily wet cuttings by vermicomposting was successfully accomplished. The composts were beneficially used as part of growing media for landscape plants; ryegrass, coniferous, and deciduous trees, and the fertilization effect was compared with commercial NPK fertilizers. The plant growth studies showed that the composts produced by treating artificial oily drill cuttings by vermicomposting had considerable fertilizing effect on ryegrass and trees.

Sammendrag

The forwarding of logs at harvest areas once the harvesting is done is planned manually by experienced operators. To improve their efficiency and simplify the planning we have developed and tested a decision support system at a major Swedish forest company. The system is based on a combination of a geographic information system (GIS), global positioning system (GPS), and optimization routines to solve the underlying vehicle routing problem. The routes for the forwarders are found by using a repeated matching algorithm. The solution time is short, and it is possible to find routes dynamically in a real-time environment. The geographic information required is found by using a GPS together with data obtained from the bucking software in the harvesters. To show the routes and location of the forwarder, we make use of a GIS that is connected to the GPS. We report on a study with savings in the distance travelled of 8% and numerical tests on the solution methodology. We also compare the proposed solution method with some well-known routing methods.

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Sammendrag

After two decades of monitoring forest health in Europe, in response to concern for negative effects of air pollution, a similar worry is now increasing in China. In a co-operative project between Chinese and Norwegian researchers a forest monitoring was implemented in the acid rain region in south China. During 2000–2004 two small watersheds were monitored: TieShanPing (TSP) near ChongQing City and LuChongGuan (LCG) near GuiYang City. They are covered by Masson pine (Pinus massoniana) forest. The methodology of the European intensive forest monitoring programme (ICP-Forests level-II) was adopted; including crown assessments, foliar chemistry, air and soil chemistry, and more. This paper presents results of this co-operative project. Considerable forest damage was revealed by monitoring the crown condition of Masson pine trees. The average defoliation percentage for all assessed trees (predominant, dominant and co-dominant pines, corresponding to Kraft classes 1–3) in the more acidified TSP was over 40% and remained stable throughout the monitoring period, accompanied by an extremely high mortality in some years. In contrast, the defoliation in the less acidified LCG was relatively low but increased considerably, from 16% to around 40%, within the 4 monitoring years. The significance of air pollution for the forest damage remains uncertain. The annual SO2 concentration in TSP and LCG is about 2 and 4 times higher than the critical level of 20 μg m−3 given in the LRTAP convention for effects on forests. Therefore the air pollution effects cannot be ruled out as contributing factors for forest damage. However, this cannot be substantiated based on the presented monitoring data since none of the specific symptoms of air pollution damage were observed. Furthermore, an analysis of the monitoring data did not reveal any significant correlation between defoliation and the soil chemical properties. It is noteworthy that the evident agents that were identified are capable of causing the observed forest damage. These agents were insect attacks and climatic stress. It is possible that the forest damage has complex causes.