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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.

2018

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The spatial distribution and niche differentiation of three closely related species (Erysiphe alphitoides, Erysiphe quercicola and Erysiphe hypophylla) causing oak powdery mildew was studied at scales ranging from the European continent, where they are invasive, to a single leaf. While E. alphitoides was dominant at all scales, E. quercicola and E. hypophylla had restricted geographic, stand and leaf distributions. The large-scale distributions were likely explained by climatic factors and species environmental tolerances, with E. quercicola being more frequent in warmer climates and E. hypophylla in colder climates. The extensive sampling and molecular analyses revealed the cryptic invasion of E. quercicola in nine countries from which it had not previously been recorded. The presence of the three species was also strongly affected by host factors, such as oak species and developmental stage. Segregation patterns between Erysiphe species were observed at the leaf scale, between and within leaf surfaces, suggesting competitive effects.

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The Svalbard Global Seed Vault was opened in 2008. The aim was to secure genetic diversity of crop plants important to future food production. The Seed Vault has the capacity to store 4.5 million seed samples, each containing on average 500 seeds sealed in airtight aluminum bags. By the end of 2016, the Vault had approximately 880,000 accessions representing more than 5000 plant species. The samples, originating from 71 gene banks and research institutes from all across the world, include major food crops such as wheat, rice, barley, sorghum, maize, legumes and forage crops, and vegetables. The seed samples are duplicates (backups) of seed stored in national, regional and international gene banks. Deposits can only be made by following a depositor agreement and the seed samples in the Vault remain the property of the depositing gene bank. The Vault is situated in permafrost at -3 to -4°C, but artificial cooling maintains a temperature of -18°C inside the Vault. Management of the Vault is secured through an agreement between the Norwegian Ministry of Agriculture and Food, the Crop Trust and the Nordic Genetic Resource Centre (NordGen). Secure storage of gene bank seeds in Svalbard was initiated during the 1980s, when the Nordic Gene Bank placed a collection of seed duplicates in an abandoned coal mine outside Longyearbyen in Svalbard. In addition to the secure storage of the base collection, a study of the longevity (germination and seed health) in long-term storage (100 years) in permafrost was started in 1986. A total of 42 seed samples of 16 common agricultural and horticultural Nordic species were included in the study. A set of sub-samples has been taken out for analyses every two and a half years during the first 20 years, and are taken out every five years for the next 80 years.

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Private forests are widespread in Europe providing a range of ecosystem services of significant value to society, and there are calls for novel policies to enhance their provision and to face the challenges of environmental changes. Such policies need to acknowledge the importance of private forests, and importantly they need to be based on a deep understanding of how property rights held by private forest owners vary across Europe. We collected and analysed data on the content of property rights based on formal legal requirements existing in 31 European jurisdictions. To allow a comparison across jurisdictions, we constructed an original Property Rights Index for Forestry encompassing five rights domains (access, withdrawal, management, exclusion and alienation). We documented substantial variation of the private forest owners’ rights, and notably to i) make decisions in operational management and the formulation of management goals, ii) withdraw timber resources from their forest, and iii) exclude others from the use of forest resources. We identified broad relations between the scope for decision making of private forest owners and jurisdictions’ former socio-political background and geographical distribution. The variation in the content of property rights has implications for the implementation of international environmental policies, and stresses the need for tailored policy instruments, when addressing European society’s rural development, the bioeconomy, climate change mitigation measures and nature protection strategies.

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Degradation of organic chemicals in natural soils depends on oxidation-reduction conditions. To protect our groundwater resources we need to understand the degradation processes under anaerobic conditions. Available iron and manganese oxides are used as electron acceptors for anaerobic degradation and are reduced to the dissolved form of metallic cations in pore water. To monitor this process is a challenge, because anaerobic conditions are difficult to sample directly without introducing oxygen. A few studies have shown an impact of iron reduction on spectral induced polarisation (SIP) signature, often associated with bacterial growth. Our objective is to study the impact of iron and manganese oxide dissolution, caused by degradation of an organic compound, with spectral induced polarisation signatures. Twenty-six vertical columns (30 cm high, inner diameter 4.6 cm) were filled with a sand rich in oxides (manganese and iron) with a static water table in the middle. In half of the columns, a 2 cm high contaminated layer was installed just above the water table. As the contaminant degrades, the initial oxygen is consumed and anaerobic conditions form Every three days over a period of one month, spectral induced polarisation (twenty frequencies between 5mHz and 10 kHz) data were collected on six columns: three contaminated replicates and three control replicates. Chemical analysis was done on twenty columns assigned for destructive water sampling, ten contaminated columns and ten control. The results show an increase of the real conductivity associated with the degradation processes, independent of frequency. Compared with the pore water electrical conductivity in the saturated zone, the real conductivity measurement revealed the formation of surface conductivity before iron was released in the pore water. In parallel, we also observed an evolution of the imaginary conductivity in both saturated and unsaturated zones at frequencies below 1 Hz. Overall, the anaerobic reduction of iron and manganese oxide during the organic degradation increased both the conductive and polarisation component of the complex conductivity.

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The ericaceous shrub bilberry (Vaccinium myrtillus L.) is a keystone species of the Eurasian boreal forest. The most optimal light condition for this plant is partial shading. Shade from the forest canopy depends on the stand density, a forest attribute that can be manipulated by forest managers. Most previous studies of the relationship between bilberry abundance and forest density have not explored the potentially modifying impacts of factors like stand age, tree species composition, and the solar irradiation at the site, as determined by location and topography. Using data from the Norwegian National Forest Inventory, we developed a generalized linear model applicable to estimate local bilberry cover across a wide range of environmental conditions in Norway. The explanatory terms in the final model were stand density (basal area per ha), solar irradiation, stand age, percentages of deciduous, pine, and spruce trees, summer (June-August) mean temperature and precipitation sum, mean temperature in January, site index, and soil category, in addition to the two-way interactions between stand density and the following: solar irradiation, stand age, percentage of deciduous trees, and percentage of Norway spruce (Picea abies). The final model explained ca. 21% of the total variation in bilberry cover. We conclude that a stand density of c. 30 m2 ha−1 in general will create favourable conditions for bilberry. If the forest is younger than 80 years old, or dominated by Norway spruce or deciduous trees, the optimal stand density is reduced to around 20 m2 ha−1. In a forest dominated by Scots pine (Pinus sylvestris), basal areas up to 40 m2 ha−1 would be beneficial to bilberry abundance. Our results demonstrate the importance of considering interactions between stand density and other stand and site characteristics.

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SENSOR TECHNOLOGY TO DETECT TICK-BORNE FEVER IN SHEEP ON RANGE PASTURE? Lise GRØVA 1), Boris Fuchs 2), Emma BRUNBERG 3), Unni Støbet LANDE 2), Kristin SØRHEIM 2), Svein Olav Hvasshovd 4), Solveig Marie Stubsjøen 5) 1) NIBIO, Norwegian Institute of Bioeconomy Research, Gunnars veg 6, 6630 Tingvoll, Norway; lise.grova@nibio.no 2) Inland Norway University of Applied Sciences, Campus Evenstad, Elverum, Norway 3) NORSØK, Norwegian Centre for Organic Agriculture, Gunnars veg 6, 6630 Tingvoll, Norway; emma.brunberg@djurskyddet.se 4) NTNU, Norwegian University of Science and Technology, Trondheim, Norway 5) VETINST, Norwegian Veterinary Institute, Oslo, Norway More than two million sheep graze on unimproved, rough grazing land during the summer months each year in Norway. Free ranging sheep are perceived to experience high level of animal welfare through their opportunity to perform natural behaviour, but these benefits are compromised when sheep experience predator attacks, disease and accidents. Ensuring animal health and welfare in farming systems gets increased attention, and new policies and legislations are implemented. About 125 000 sheep (6-7%) are lost on such pastures every year. Tick-borne fever (TBF) is a disease considered to be a major challenge in sheep farming during the grazing season along the coast of south-western Norway. Clinical signs of TBF is ofte observed within 14 days of infection, starting with an abrupt rise in rectal temperature (often above 41o C). Being able to monitor farm animals on range pastures is increasingly important and implementing available technology for this purpose should be exploited. Implementation of sensor technology in rangeland sheep farming can monitor physiological parameters, such as body temperature (T). Integrating such sensors in a GPS tracking system may contribute to detect, locate and treat sick animals, as well as improve our knowledge of animal health in time and space in rangeland farming systems. The objective of the work presented here is to evaluate if a temperature sensor can be used for early detection of Tick-borne fever (TBF). In 2016, temperature sensors (Star Oddi, Iceland) were implanted in the abdomen of 20 lambs in a one sheep flock in a TBF risk area and in 20 lambs from one flock in a non-TBF risk area in Norway. The sensors were programmed to log temperature every 10 minutes, and were implanted in lambs in early June and collected in early September to retrieve data. Temperature data were obtained from 13 temperature loggers from lambs in the TBF risk are and 14 loggers in the non-TBF risk area. The telemetry system (Telespor, Norway) was used on all lambs, and provided accelerometer information and real-time positioning data that was used for continuous surveillance on range pasture. All animals were monitored twice a day for approximately one month period after turned out on tick infested pastures. Number and magnitude of fever was calculated for each lamb. Preliminary results from this study will be presented at the conference. Keywords: sheep, sensor technology, temperature, tick-borne fever, rangeland

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The effect of controlled nutrient feeding during the period of short day (SD) induction of flowering has been studied in three SD berry crops. An experimental system with standardized plant material grown with trickle fertigation in controlled environments was used. In strawberry, flowering was advanced and increased when an additional N pulse was given 1-2 weeks after commencement of a 4-week SD induction period, while the opposite resulted when the treatment was applied 2 weeks before start of SD. In blackcurrant, the highest flowering and yield were obtained when fertilization was applied shortly after the natural photoperiod had declined to the inductive length in September. While generous nutrient supply during spring and summer reduced berry soluble solids in blackcurrant, this was not observed with autumn fertilization. Autumn fertilization did not adversely affect plant winter survival or growth vigour in spring. Withdrawal of fertilization prior to, or at various stages during floral induction, did not significantly affect flowering and yield in raspberry, but marginally advanced flowering and fruit ripening.

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Climate change characterized by global warming has become a hotspot of research in recent years for water resources, agriculture,ecology and other disciplines. In India, studies have shown an increasing trend in surface temperature, with decreasing trends inrainfall. Farmers are also more affected by the climate variability which has a serious influence on their production and income.The climate change and adaptation (ClimaAdapt) programme was implemented from 2012 to 2016 to build farm-level capacitiesand enhance the adaptive capacity of the agricultural and water sectors in the Krishna basin of Andhra Pradesh and Telanganastates. Water-saving interventions such as direct seeded rice, a modified system of rice intensification and alternate wetting anddrying (AWD) of rice were implemented in a cluster approach and enhanced water productivity. The training and implementationprogrammes increased the adaptation and awareness of farmers. Water measurements were carried out by usingflumes andultrasonic sensors. The area under direct seeded rice has increased to 64% in the study district and 77% of the trained farmersare adopting the practice. Capacity building, implementation and science–policy linkages are the key pillars of the programmeto improve the adaptive capacity and scaling-up of water management practices.

Sammendrag

The production of ash from wood has greatly increased the last years, because biofuels are increasingly being used for heating and energy production. The ash may either be viewed as a waste problem, or as a resource. Wood ash has a liming effect and contains essential nutrients (P, K, Ca, Mg) which can be exploited for soil fertilisation. With enhanced knowledge about where and how wood ash addition may increase forest growth - without having negative effects on the environment - wood ash may become a renewable nutrient source. We studied the effect of fertilizing a Norway spruce (Picea abies) stand on relatively high site index in SE Norway with ash, nitrogen, or ash + nitrogen. After five years, both current annual increment and standing volume was best in the ASH + N treatment and least in the Control plots. The field trial should be followed for a longer period of time, as the ASH + N treatment still shows an increasing growth trend after five years.