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.
2007
Abstract
No abstract has been registered
Abstract
In the context of an ongoing project on REMote sensing of FORest health (REM-FOR), we analyze airborne high-resolution hyperspectral images of a pine-dominated region in southeast Norway heavily attacked by the Pine sawfly Neodiprion sertifer, leading to severe defoliation. Leaf Area Index (LAI) is used as a proxy of the crown density, and comparing LAI maps from before and after the attack lead to indicators for damage extent. We discuss the application of the Forest Reflectance Model (FRT) of Kuusk and Nilson, which was designed for the application to (managed) Northern European Forests, to model the spectral response from the canopy. It is based on conventional forest inventory data, species-dependent parametrized crown shapes, canopy LAI, needle clumping index, and needle optical properties. Here, however, we run the model in an inverse mode, by iteratively minimizing the discrepancy between measured and simulated reflectances, and predicting the LAI, keeping known parameters of the model fixed. The LAI values are then compared to those obtained with either ground-based Licor LAI2000 measurements, or with airborne laser-scanning. Some preliminary results of this modelling concept for the case study are discussed.
Authors
Isabelle Schülli-Maurer Daniela Sauer Karl Stahr Ragnhild Sperstad Rolf SørensenAbstract
We investigated the development of Albeluvisols and Podzols with time in southern Norway. The Vestfold region at the western shore of the Oslofjord was chosen because it is characterized by continuous glacio-isostatic uplift for the last 12,000 years. Due to the permanent elevation process, no distinct marine terraces have been built, and the age of the sediments continuously increases with distance from the modern coastline. Albeluvisol development was assessed in a soil chronosequence on loamy marine sediments with ages ranging from approximately 1,800 to 10,200 years. The most obvious change during soil development was that after 4,500 - 5,000 years light tongues intruded from the E horizon into the B horizon, and became more pronounced with time. The combined thickness of the A and E-horizons was constant at 40 ± 3 cm in 9 of the 12 profiles and did not change with age. The organic matter content of the A-horizons, the fine silt to coarse silt ratio of the Btg horizons and the Feo/Fed ratio all decreased with soil age, whereas the thickness of the organic surface horizon and B horizon, as well as the Fed/Fet ratio all increased. Podzol development was investigated in a chronosequence on sandy beach sediments, the ages of the soils ranging from 2,400 to 8,500 years. All soil properties investigated - the organic matter content of the B horizons, clay content, Feo, Alo, Sio, Feo/Fed and Fed/Fet - tend to increase with advancing podzolization, and are strongly correlated with soil age. Topsoil pH values decrease with age. The characteristic Bh and Bs horizons had developed after approximately 4,000 years.
Authors
Daniela Sauer Isabelle Schülli-Maurer Ragnhild Sperstad Rolf Sørensen Karl StahrAbstract
The coastal areas of Scandinavia provide suitable conditions for studying soil development with time, due to glacio-isostatic uplift. Our study area is located along both sides of the Oslofjord (Vestfold and stfold). The climate in this area is rather mild although it is located between 59 and 59 40 latitude. The mean annual temperature ranges from 5.4 to 6. 0 C. Precipitation is 9751094 mm year1 in Vestfold and 751829 mm year1 in stfold. Due to the steadiness of the uplift, no separate terraces were formed in the study area, but soils continuously get older from the coast inland. We established two soil chronosequences comprising six pedons each, one in Vestfold (1650 9000 years) and one in stfold (300011050 years). The ages were estimated by use of several sea level curves established for various locations in the area, based on calibrated radiocarbon datings. The parent material is loamy marine sediment. The geological basement below the sediment consists of basic magmatite (monzonite, latite) in Vestfold and predominantly acid magmatite (granite) in stfold. Higher precipitation in Vestfold leads to earlier beginning of clay illuviation. Clay coatings are perceptible in Vestfold already in the 1650 years old soil. In stfold they become visible for the first time in the 3500 years old soil. The E horizon becomes lighter with age, but its thickness stays constantly around 40 cm in both areas. The development of the characteristic albeluvic tonguing starts after 4000 to 5000 years. The tongues initially develop mainly along intersections of cracks. Due to ongoing leaching they increase in length and width, progressively consuming the prisms in between the cracks in the upper part of the Bt horizon. Base saturation in the upper 25 cm exhibits a decrease with time which can be best described by an exponential model, while pH (water) stays constantly at pH 4.4 0.4 in all soils covering a range of 1650 to 11050 years in age. These findings indicate that the soil pH is buffered by protonation of surface charges occupied by exchangeable base cations over a time span of more than 9000 years. The Fed/Fet ratio shows an increase with time which can be described by both, a linear or potential model, reflecting progressive iron release from mineral weathering. The Feo/Fed ratio shows a linear decrease indicating increasing degree of iron oxide crystallization.
Authors
Gerhard Weiss Suzanne Martin Anne Matilainen Birger Vennesland Carmen Nastase Erlend Nybakk Laura BouriaudAbstract
This article examines innovation processes in forest recreational services on the basis of case studies in five European countries with differing institutional backgrounds of forest ownership and access rights. The analysis reveals that forest-related recreation services are developed under varying institutional conditions and on public as well as private land. Ideas for innovations in recreational services may come from within but often outside the forestry sector. Financing is provided from public and private sources. Both public and private spheres have important roles in providing natural, human and financial resources and usually a network of public and private actors are involved in innovation processes. Of particular importance are cross-sectoral interactions between forestry and tourism. Greater institutional support is needed for the development of forest-related recreation services because the field is at an early stage of development. It is concluded that support should focus on providing ideas and financial resources for product development and on facilitating cross-sectoral interaction between forestry and tourism actors. A particular need is seen for development of models for durable interaction between land owners and tourism operators on a regional scale.
Authors
Jørn Kristian LilengAbstract
No abstract has been registered
Authors
O. Janne Kjønaas Richard Frederic WrightAbstract
To determine the source of dissolved inorganic nitrogen (N) in runoff, approx. 35 kg N enriched with the stable isotope 15N (2110‰ δ15N) was added to a mature coniferous forested catchment for one whole year. The total N input was approx. 50 kg ha-1 year-1. The enrichment study was part of a long-term whole-catchment ammonium nitrate addition experiment at Gårdsjön, Sweden. The 15N concentrations in precipitation, throughfall, runoff and upper forest floor were measured prior to, during, and 3-9 years following the 15N addition. During the year of the 15N addition the δ15N level in runoff largely reflected the level in incoming N, indicating that the leached NO3- came predominantly from precipitation. Only 1.1% of the incoming N was lost during the year of the tracer addition. The cumulative loss of tracer N over a 10-year period was only 3.9% as DIN and 1.1% as DON.
Authors
Erlend Ystrøm Haartveit Leif Kjøstelsen Bård Strand JacobsenAbstract
The project Woodflow is a 3-year project aiming at quantifying logistics costs for wood products in a supply chain from manufacturer to consumer. Woodflow is financed by the Research Council of Norway, Innovation Norway and Optimera AS. The work is carried out in Optimera’s distribution network in Norway. In this paper we present and discuss two methods for estimating time consumption, one for material handling and one for activities in the information flow. For material handling a method based on time studies has been modified and adapted to the situation in a distribution centre. For activities in the information flow performance measures of sales personnel are combined with information about registered orders to develop estimates for time consumption for entering orders and order lines. These will also be used to estimate time consumption for other tasks in the information flow. The estimates for time consumption will later be combined with the time costs of the performing actors to calculate logistics costs for material handling and for activities in the information flow.
Authors
Erlend Ystrøm Haartveit Ingrid KnottenAbstract
Traceability in a supply chain can be established using several different technologies. The basic idea is marking each item with an identifier which can be rgistrered as the item flows downstream in the supply chain. Abilities to track and trace products and components have become requirements in many supply chains. Systems for traceability may also be used to improve logistics across the supply chain. Supply chain management implies applyin holistic perspectives on solutions, spanning from the vendor of raw materials to the consumer. This article presents a Norwegian case in which tracebility solutions based on Radio Frequency IDentification (RFID) were tested in a supply chain for poles delivered to power lines. Logs were marked with standard RFID tags in the forest and were registered with a standard RFID reader on several sages frm forest to finished product. The standard equipment performed well even when exposed to rough handling, high and low temperatures and high pressure. The results show that even when individual actors may benefit from implementing traceability solutions it is challenging to develop joint and profitable solutions for several actors in a supply chain. Three main obstackles were identified as impediments for supply chain traceability. There are diffrences in objectives as som firms focus on optimising logistics and production, while others aim at reducing errors from manual registrations. There are differences in requirements for technical solutions, especially concerning where the tag should be placed on the log. Finally, there are differences in willingness and readiness to adopt new technology.
Abstract
Furfurylated wood is an environmentally friendly, chemically treated, wood product with improved characteristics. Quality control of furfurylated wood is still performed manually by subtracting the initial weight of a treated sample from its final weight, then dividing the result by the initial weight. Expressed as a percentage, this results in a value that represents the weight percent gain (WPG) of the treated sample and thus the degree of modification. The major disadvantage of this quality control method is that the production parameters are needed to determine WPG, since the initial weight cannot be deduced from a treated wood sample. In this paper the use of ThermoGravimetric Analysis (TGA) is presented as a potential quality control method for furfurylated Scots pine (Pinus sylvestris L.). The technique is independent of production parameters and, therefore, enables third parties to determine the WPG of any furfurylated wood product. Three validation trials have been performed with the same validation samples, but varying TGA settings and with different Partial Least Square regression models (PLS-models). Although the method needs further improvement, it has shown good accuracy and precision. Therefore, it is con