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.
2006
Forfattere
Tor Gunnar Vågen Masy-A A Andrianorofanomezana Salmata AndrianorofanomezanaSammendrag
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.
Forfattere
Tor Gunnar VågenSammendrag
Madagascar is often portrayed as a global environmental hotspot with widespread deforestation and environmental degradation. Quantitative and spatially explicit data on ecological change are, however, scarce and current estimates are often based on simplistic representations of deforestation and land use change. Significant uncertainties in current estimates therefore remain. The present study was conducted to assess deforestation and other important complex land use change trajectories in the eastern highlands of Madagascar. A timeseries of satellite imagery dating from 1972 to 2001 was used to analyse overall change and rates of change between different land use types in the study area. Forest cover in the study area was approximately 8060 ha in 1972 and 4278 ha in 2001. Rates of deforestation were not, however, constant throughout this period, but varied from 52 ha yr1 (1972"1992) and 341 ha yr1 (1992"1999). The increased rates in the 1990s were attributed to turbulent political conditions on the island during the latter period and shows the complex relationships between social, political and ecological processes governing deforestation and land use change processes. Accessibility (distance to villages and roads) and elevation were shown to be the most important predictors of deforestation risk in the study area. Intensive cultivation of slopes (tanety) increased by about 3400 ha ( 65%) during the study period, a significant part of which came from cultivation of grassland savanna (net increase 1700 ha). These trends were found to be indicative of increasing pressure on available land resources in the region, leading to extensive cultivation of marginal grasslands and ultimately significant soil fertility decline.
Forfattere
Frode VeggelandSammendrag
This report explores how equivalence and mutual recognition have been applied by the European Union (EU) in order to facilitate trade. The EU is of particular interest in this area because it has been in the forefront internationally with regard to applying these tools, both in its internal market project and in its external trade relations. The report includes an empirical mapping of EU’s experience with applying equivalence and mutual recognition as trade facilitating tools. The aim here is to increase the understanding of how these tools can be relevant and important in a wider global context, in particular with regard to food trade. Furthermore, based on this experience some of the challenges that countries are faced with when applying these tools are highlighted thus allowing some assessments of the prospects of and difficulties in achieving trade facilitation through these means. Chapter 2 includes an account of some of the regulatory approaches that the EU has pursued in its attempts at realising an internal market, from the adoption of common rules, to mutual recognition and the «Better Regulation» programme included in the Lisbon strategy. Chapter 3 discusses EU’s rules for third-country relations. Furthermore, some of EU’s mutual recognition and equivalence agreements are explored. In addition to these, Chapter 3 includes an account of one-way judgements of equivalence included in EU’s rules for imports of organic food and fishery products. Chapter 4 presents EU’s work and positions on equivalence and mutual recognition in the WTO and the Codex Alimentarius Commission. Chapter 5 includes an assessment of the EU’s experience with mutual recognition and equivalence. Finally, in Chapter 6 some conclusions and final remarks are made. […]
Forfattere
Mikael Rönnqvist Håkan Broman Mikael Frisk Mikael RönnqvistSammendrag
The storm Gudrun hit southern Sweden in January 2005 and approximately 70 million cubic meters of forest was wind felled. The existing logistic planning at forest companies in the damaged area had to be changed over night. There was a direct shortage of both harvest and transportation capacities. Key questions that arised were which terminals to use, where to harvest, where to store, which transportation modes (truck, train, ship) to use. In this paper we describe how the forest company Sveaskog made use of Operations Research (OR) as an important decision support in their supply chain planning in the aftermath of the storm.
Forfattere
Ingvald Røsberg Jon Frank Arne O. StuanesSammendrag
Soil uptake of N, P, and K from the unfertilized plots leads to a depletion of these elements, but also very little leaching. Upon addition of N, P, K, Mg, Ca, and S, soil uptake and nutrient accumulation in the soil usually increased at the same time. The high doses of N, P, K, and S in the "optimal" treatment gave a distinct response with higher uptake from the soil and higher accumulation in the soil. No P was leached from the soil, while about one fourth to one third of the applied N, K, and Mg were leached. The treatment induced an unacceptably high nitrate leaching, and must therefore be regarded as "suboptimal". (c) 2006 Elsevier B.V All rights reserved. Tree growth and nutrient cycling of N, P, K, Mg, Ca, S, and B were examined after four growing seasons in a pine ecosystem in southern Norway. The Scots pine (Pinus sylvestris L.) stand, growing on a Cambic Arenosol, was 33 years old and had a medium site index class. The randomized block experiment had six treatments and three replicates: (1) control, (2) 3000 kg per hectare lime, (3) 3000 kg per hectare dolomite, (4) 3000 kg per hectare dolomite and (5) 6000 kg per hectare dolomite, both treatments (4 and 5) with the fertilizers KCl and superphosphate, and (6) 3000 kg per hectare dolomite with KCl, superphosphate, NH4NO3, kieserite, and borax, and denoted as "optimal" treatment. The "optimal" treatment gave a significantly higher annual increase in tree height and diameter, stand basal area and volume than the control and lime treatments. The dry mass of needles and branches increased slightly for the treatments nos. 3-5 compared to the control and lime treatments, with the most distinct increase for the "optimal" treatment. Highest dry mass of stem wood + bark was found for the treatments nos. 3-6. The nutrient contents in needles were highest for the "optimal" treatment, while dolomite without fertilizer elevated the Mg content in both needles and branches. The nutrient concentrations in the current year's needles increased the most for the "optimal" treatment, except for Ca and Mg. The addition of lime gave the highest concentration of Ca in needles compared to the other treatments. The amounts of N, P, S, and B in the forest floor were also highest for the "optimal" treatment. Soil uptake of N, P, and K from the unfertilized plots leads to a depletion of these elements, but also very little leaching. Upon addition of N, P, K, Mg, Ca, and S, soil uptake and nutrient accumulation in the soil usually increased at the same time. The high doses of N, P, K, and S in the "optimal" treatment gave a distinct response with higher uptake from the soil and higher accumulation in the soil. No P was leached from the soil, while about one fourth to one third of the applied N, K, and Mg were leached. The treatment induced an unacceptably high nitrate leaching, and must therefore be regarded as "suboptimal".
Forfattere
Reidar Elven Torbjørn Alm Harald Bratli Arve Elvebakk Torstein Engelskjøn Eli Fremstad Marit Mjelde Bjørn Moe Oddvar PedersenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Chemical recalcitrance of specific molecules is one of the factors governing organic matter stabilization in soils. Little is known about the relationship between the chemical nature and the dynamics of soil organic matter at the long-term scale. Lignin molecules are abundant in plant tissues and are generally considered as slowly biodegradable in soils. In a previous study, using compound specific isotopic tracer techniques applied to agricultural lands converted from C3 to C4 cropping, we showed that lignin turnover was faster than that of total organic carbon. Lignin dynamics was well described by a two-pool model, distinguishing lignins in fresh plant residues and those more closely associated to the soil matrix. These two pools may be transformed into non-lignin products, which includes CO2, microbial biomass and chemical substances, which are no longer recognized as lignin derivatives. The aim of the present work was to study the nature and dynamics of these non lignin products formed during lignin degradation in a laboratory incubation of 13C-labelled lignin with soil. Maize plants were grown for 1 month under 13C enriched CO2. The lignins of leaves and stems were isolated after treatment with cellulolytic enzymes and solubilization in dioxane:water (1:9). The Milled Maize Lignin (MML) obtained had a 13C abundance of 1.4 %. Solid-state 13C NMR spectroscopy of MML before analysis showed that the isolation method produces a lignin-cellulose complex, as indicated by the presence of some polysaccharides (the 60-115 ppm region represented about 40 % of total C of isolated lignins). Lignins were incubated with soil (1 mg lignin/g soil) at 20°C in sealed glass jars and analyzed after 1, 2, 4, 8, 16, 32 and 48 weeks. A control sample was incubated without lignin. We monitored the mineralization, solubilization and incorporation in the microbial biomass of lignin C by measuring 13C enrichments in respired CO2, water-soluble fractions, and fumigated biomass, respectively. Lignins remaining in incubated soils were quantified by CuO oxidation and the 13C contents of vanillyl, syringyl and cinnamyl units (VSC) were measured. After 4 months, 3% of the 13C of the labelled lignin was mineralized. This mineralization rate was less than that found by Martin and Haider (1979) for DHP lignins but more than the 5% per year found in situ by Dignac et al. (2005). Less than 0.5% of incubated lignin C was water soluble and 0.5 % was incorporated into the soil microbial biomass. The main part (96%) of incubated MML remained in soil. We used compound-specific isotopic analysis of the CuO oxidation products and pyrolysis analysis to estimate the proportion of intact lignins remaining in the soil.
Forfattere
Mauritz Åssveen Oddvar Bjerke Lasse WeisethSammendrag
Sorter av bygg, havre og vårhvete er prøvd i forsøk på Østlandet og i Midt-Norge. Nye sorter og linjer prøves sammen med markedssorter. Siste sesongs resultater og sammendrag over år presenteres
Forfattere
Ricardo Holgado Stig Andersson Christer MagnussonSammendrag
Cereal cyst nematodes, Heterodera spp. are known world-wide as parasites of cereals and grasses. Surveys of cereals in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country, and that H. avenae (oat cyst nematode) is the most common species followed by H. filipjevi (rye cyst nematode). H. avenae and H. filipjevi are of economic importance in Scandinavia. H. avenae has two common pathotypes, Ha 11 and Ha 12. Work in Sweden, however, has detected the three additional pathotypes H. avenae- Knislinge, H. avenae- Ringsåsen and H. avenae- Våxtorp. These pathotypes were detected also in the Norwegian surveys. In Sweden H. filipjevi has two pathotypes, "East" and "West". In Norway, only the pathotype "West" has been detected so far. Nematode management practices must be based on the knowledge of the population dynamics, the population density required to cause economic damage, and the measures capable of reducing or keeping the population density below the threshold for economic damage. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes. For several years it has been known that resistance to cereal cyst nematodes may be found in some commercial cultivars, although no conscious breeding for resistance has been attempted. In 2004 and 2005 a majority of cereal cultivars on the Norwegian market were tested for susceptibility/resistance towards H. avenae pathotype Ha 11, H. avenae pathotype "Våxtorp" and H. filipjevi pathotype "West" The test program included 30 cultivars of barley, 23 cultivars of oats and 6 cultivars of summer wheat. The objective of this work was to increase our knowledge on cultivar selection for farmers. Resistance against Ha11 was found in 5 barley, 3 oat cultivars and in 1 wheat cultivar. Resistance against H. avenae pathotype "Våxtorp" was not present in barley, but 4 oat cultivars, and 1 wheat cultivar were resistant. For H. filipjevi "West" resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. In Norway management systems based on careful nematode identification and good knowledge on appropriate resistant cultivars are in operation. Resistant barley is generally recommended when nematode populations are high due to its high tolerance compared to resistant oats. Farmers implementing this program have reported increased cereal yields on the average of 1000 kg /ha. It has been calculated that by implementing this program in full the county of Vestfold could make an economic gain of 800 000 " annually.
Forfattere
Ragnar Eltun Thor Johannes Rogneby Hanne HombSammendrag
Forsøket viste at ettårig kløvereng er en god forgrøde for korn uavhengig av antall pussinger i engåret og pløyetidspunkt for enga. Planterester fra underjordiske plantedeler og positive effekter på jordstrukturen er trolig de viktigste årsaken til den gode ettervirkningen av kløvereng. Hvis en har bruk for graset fra første slåtten, kan dette således gjerne høstes uten at det går særlig på bekostning av ettervirkningen. For å få best mulig vekst av enga vil en anbefale 3-4 kuttinger. Pløyetidspunktet påvirket ikke kornavlinga i dette forsøket.