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.
2011
Forfattere
Lars Tørres HavstadSammendrag
Different procedures for managing stubble and regrowth in meadow fescue (Festuca pratensis Huds.) seed crops were examined in two experimental series in southeast Norway. The first series investigated cutting and removal of stubble shortly after seed harvest in late July/early August, combined with cutting of regrowth (forage harvest) in September or October or burning of the wilted aftermath in early spring. Except for one crop with more than 30-cm stubble, stubble removal shortly after seed harvest did not improve seed yield in the following year. On average for plots with and without stubble removal in seven seed crops, forage harvest on 5 September or 1 October reduced seed yield by 9 and 12%, respectively. The reductions were due to smaller inflorescences, probably reflecting lower carbohydrates reserves. In most trials, the highest seed yield, on average 9% above that of the uncut and unburned control, was found after burning in spring. The second experimental series investigated flail-chopping in spring as an alternative to burning, and the effect of delaying either of the two treatments. On average for four trials, burning and flail-chopping before growth initiation increased seed yield by, in turn, 20 and 12% compared with the untreated control. A two-to-three-week delay in fail-chopping had no negative impact, but a two-week delay in burning reduced seed yield back to the uncut/unburned control level. Based on these trials, growers are recommended to burn meadow fescue seed crops in early spring rather than removing stubble and regrowth in autumn. If burning in early spring is not possible, flail-chopping is recommended within two weeks after growth initiation.
Forfattere
Håvard Kauserud Einar Heegaard Rune Halvorsen Lynne Boddy Klaus Høiland Nils Christian StensethSammendrag
Most basidiomycete fungi produce annual short-lived sexual fruit bodies from which billions of microscopic spores are spread into the air during a short time period. However, little is known about the selective forces that have resulted in some species fruiting early and others later in the fruiting season. This study of relationships between morphological and ecological characteristics, climate factors and time of fruiting are based upon thorough statistical analyses of 66 520 mapped records from Norway, representing 271 species of autumnal fruiting mushroom species. We found a strong relationship between spore size and time of fruiting; on average, a doubling of spore size (volume) corresponded to 3 days earlier fruiting. Small-spored species dominate in the oceanic parts of Norway, whereas large-spored species are typical of more continental parts. In separate analyses, significant relationships were observed between spore size and climate factors. We hypothesize that these relationships are owing to water balance optimization, driven by water storage in spores as a critical factor for successful germination of primary mycelia in the drier micro-environments found earlier in the fruiting season and/or in continental climates.
Sammendrag
Oil transportation from the Russian part of the Barents Region along the Norwegian coast had insignificant volumes before 2002. However, in 2002 there was a dramatic increase in oil shipment, when 4 million tons was delivered westwards by the Barents Sea. In 2003, the volume reached 8 million tons. The trend continued in 2004, and about 12 million tons of export oil and refined products were transported from the Russian part of the Barents Region to the western market along the Norwegian coast. From 2005 to 2008, the annual shipment volumes were on the levels between 9.5 and 11.5 million tons. In 2009, Russian oil-and-gas export cargoes carried by the Barents Sea rose to 13 million tons, and in 2010, exceeded the level of 15 million tons. Norwegian Snøhvit, the first offshore production in the Barents Sea, added to these volumes 5 million cubic metres of liquefied gases (LNG and LPG) each of two recent years. The terminals loading oil for export in the Russian Western Arctic seas have been continuously developed, and the overall shipping capacity has been enlarged. The changes in oil volumes carried for export through the Barents Sea during the recent years were not so much dependent on the terminals‟ capacities and logistic schemes as on the external factors. The changes in the export taxes by the State and rates for cargo transportation by Russian railways, development of new trunk pipelines and sea terminals in the Baltic Sea and Far East by Transneft, bankruptcy of Volgotanker were a few examples that induced oil transport operators to develop new terminals in the Kola Bay and to focus more on petroleum products than crude oil. The big oil export challenges that occurred in the recent years due to conflicts between Russia and neighbouring transit countries made the Russian Government and Transneft to reorient the Russian oil export routes and increase the capacities of the Baltic Pipeline System (BPS) to 75 million tons in 2007, with the prospects to reach 150 million tons in 2015. Construction of Eastern Siberia-Pacific Ocean pipeline (ESPO) was launched, the first phase with a branch to China was put on stream in 2010, and a new terminal in the Far East started to ship oil for export. In the south, the project of Burgas-Alexandropoulis pipeline was developed. In the north, Kharyaga-Indiga pipeline project was frozen because a new Varandey terminal came on full scale. The year of 2009 started with an export gas transit conflict between Russia and Ukraine. The Government of Russia and Gazprom highlighted the importance of constructing Nord Stream and South Stream gas pipelines through the Baltic and the Black seas to let Russia export natural gas to Western Europe bypassing its neighbouring countries, the former Soviet sister-republics. In 2009, Russia launched its first LNG plant in Far East in Sakhalin. Three more LNGs are planned in the Arctic, in the Kola Peninsula, in Nenets region, and in Yamal. Those plants can start shipping liquefied gas in 2016-2017. The first oil from offshore production in the Russian Barents should come from Prirazlomnoye oil field. Prirazlomnaya platform left Severodvinsk and came to Murmansk for completion in the fall of 2010. The plan is to deliver the platform on its production destination and put the oil field on stream in 2011. The Prirazlomnaya platform will be the second big offshore installation in the Pechora Sea. The first one, 12 million tons Varandey terminal, was launched in 2008, and already in 2009 sent more than 7 million tons of crude oil for export. Lukoil plans to increase the terminal oil offloading volumes building 8 million tons pipeline from Kharyaga to Varandey. In the present report on oil transportation in the Barents Region, we have given special attention to the description of the existing and prospective offshore and onshore oil and gas terminals in the northern regions of Russia and Norway, and their connection to hydrocarbon reserves on one hand and to the export routes on the other. We demonstrate that even without a Russian oil trunk pipeline to the Barents Sea coast, that was discussed a few years ago, the overall capacity of the terminals shipping oil and gas for export along the northern coast of Russian and Norway can reach 100 million tons in five years perspective. In Russia, about 50 million tons of crude oil and petroleum products can be delivered by railway to the Murmansk port terminals in the Barents Sea, and Kandalaksha and Arkhangelsk in the White Sea. In addition, up to 20 million tons of oil will come from the northern Timano-Pechora oil fields - 12.5 million via the new Varandey terminal, and 7.5 million from Prirazlomnoye field. Dolginskoye oil field, which is estimated to be three times as big as Prirazlomnoye, will be the next large offshore field in the Pechora Sea put on stream. With port infrastructure developed on Yamal, the terminals in the Kara Sea can ship 3 million tons of Western Siberia crude oil for export. Shtokman in the Barents Sea and Tambey in Yamal gas fields can offload 12.5 million tons of liquefied gas in 2017, when the first phases of both LNG plants are completed. In Norway, in addition to 5 million tons of liquefied gas shipped from Snøhvit, Goliat oil field in the Barents Sea should be put on stream in 2013 and produce 5 million tons of oil in 2014. In 2010, there were made a number of historic voyages by the Northern Sea Route. We will see more cargo vessel passages through this Arctic shipping lane in 2011. In a long term perspective, the Northern Sea Route will give the way for huge Yamal and Kara Sea oil-and-gas resources to the western markets via the Barents Sea; and it will also open possibilities for transit cargo transportation from Europe to Asia Pacific along the Arctic coast. In the European part of Russia there are three possibilities for shipping oil for export - through the Black Sea, the Baltic Sea, and the Barents Sea. Out of these three options, only the northern way can provide the stable cargo shipping directly to major European and North American harbours, avoiding transit challenges through neighbouring countries or heavy traffic in the sea straits. Oil pollution prevention should be the central issue during oil transportation in the Barents Sea. The year 2010 was marked with the Mexican Gulf accident, the largest oil spill ever happened in the sea that put issues of marine environmental protection against oil pollution to a high international political agenda. In this report, we pay attention to the environmental safety matters in oil transportation and Norwegian-Russian co-operation in the oil pollution prevention. We see more advanced and safer terminals and vessels operating in the region. However, the number of accidents with sea vessels was increasing worldwide the last 10 years due to human errors. Traffic control and monitoring are developed both in Norway and Russia. Establishment of an early warning and notification system between two countries should be the next step. The Treaty on a delimitation line in the Barents Sea, that was signed between Norway and Russia in 2010 and ratified in 2011, should put relations between two countries on a new level opening wider possibilities for oil-and-gas, maritime shipping and environmental cooperation.
Forfattere
Mekjell Meland Lars Sekse Clive KaiserSammendrag
‘Summerred" apples (Malus domestica) Borkh are highly susceptible to biennial bearing if not properly thinned. This results in erratic yields and also affects fruit quality adversely. Between 2003 and 2005 ‘Summered"/‘M9" trees were treated with ethephon at concentrations of 250, 375 and 500 mL·L-1 when most king flowers opened (ca. 20% bloom) or at concentrations of 500, 625 and 750 mL·L-1 when the average fruitlet size was 10 mm in diameter. The experimental design was a completely randomised block design with 6 whole tree plots per replication. Trees were sprayed to the point of run-off with a hand applicator only when temperatures exceeded 15ºC. Within two weeks after the second application fruit set was reduced linearly with increasing concentrations of ethephon to less than 1 fruitlet per cluster at the highest concentrations used. Most thinning treatments reduced fruit set significantly compared to unthinned trees. Fruit numbers per tree decreased significantly with increasing ethephon concentrations, and the highest concentrations of ethephon applied during bloom or when the average fruitlet size was 10 mm in diameter resulted in over-thinning. Yield results confirmed the fruit set response where yield reductions were significant at highest concentrations of ethephon (2.1 kg·tree-1) compared to hand-thinned trees (7.3 kg·tree-1) in 2005. All thinning treatments resulted in higher percentage of fruits larger than 60 mm diameter average fruit size compared to unthinned control fruit. Thinning resulted in significantly higher soluble solid contents, and this was especially so for hand-thinned trees. Other fruit quality parameters like yellow/green background color did not show a clear response to thinning. Fruit firmness, however, decreased slightly in all ethephon treated trees whereas return bloom was improved on all thinned trees. It is recommended that ethephon be applied at a rate of 375 mL·L-1 when king flowers open or at a rate of 625 mL·L-1 when the average fruitlet size is 10 mm in diameter. These treatments thin ‘Summerred" apples to a target of about 5 fruits·cm-2 per trunk cross sectional area or 50-70 fruits·100 flower clusters-1 without impacting fruit quality, yield or return bloom the following year.
Sammendrag
Arable weeds are generally distributed in patches, while herbicides are applied uniformly. Herbicides can be saved if only the patches are sprayed, i.e. patch spraying (PS). Bottlenecks for cost-effective PS are weed monitoring technology and valid technology-based decision rules for PS (thresholds). The novel machine vision algorithm Weedcer has been developed as an efficient weed monitoring tool for PS. Weedcer estimates the proportions of young weed leaves and cereal leaves in high resolution red–green–blue images. We conducted field trials to test relative weed cover (RWC) and relative mayweed cover (RMC) estimated by Weedcer as decision rules for PS. RWC is the total weed cover divided by the total plant cover and RMC is the mayweed cover divided by the total plant cover. The main criterion for evaluation and basis of these thresholds was the measured grain yield. Images (about 0.06-m2) were acquired with a GPS guided autonomous field robot in spring, the normal time for spraying seed-propagated broadleaf weeds in both winter – and spring cereals in Norway. Three map-based trials (weed monitoring and spraying in two separate operations) showed that mean RWC per management unit (12.0 × 12.5-m) was generally adequate. In winter wheat heavily infested with scentless mayweed (Tripleurospermum inodorum (L.) Sch.Bip.) and/or scented mayweed (Matricaria recutita L.), the mean RMC per management unit was more adequate. Progress during the project allowed three additional trials conducted in real-time (weed monitoring and spraying in the same operation). These were conducted with the robot in spring cereals, and showed that a weighted moving average of RWC per image was adequate. The sprayed and unsprayed management units in these trials were minimum 3.0 × 3.0-m and 0.5 × 3.0-m, respectively. Results indicated that the Weedcer-based thresholds should be lower in wheat (Triticum aestivum) than in barley (Hordeum vulgare).
Forfattere
Ylva-li Blanck Juan Gowda Linda-Maria Mårtensson Jakob Sandberg Ann-Mari FranssonSammendrag
The aim of this study was to ascertain whether there is a relationship between plant species richness and plant-available N, P and water in an environment subject to little anthropogenic disturbance. To accomplish this we studied the vegetation in matorral shrub-lands in northern Patagonia, Argentina. Due to the variation in slope, precipitation and aspect between the sites water status was determined using the 12C/13C fraction, δ13C, to investigate whether this was a confounding factor. The numbers of herb, shrub, liana and tree species were determined at 20 sites along an estimated precipitation gradient. Leaf P and N content and the δ13C of Berberis buxifolia were determined, as well as the soil P and N content at the different sites. A negative correlation was found between species richness and Berberis buxifolia foliar P concentration (52% of the species richness variation was accounted for), and a positive correlation was found between plant species richness and Berberis buxifolia foliar N: P ratios (54% of the species richness variation was accounted for). The relationship between species richness and foliar P was seen when all layers of vegetation were included (trees, lianas, shrubs and herbs). Foliar N showed no correlation with species richness, while soil extractable NH4 showed a weak positive correlation with the number of shrub layer species (lianas, shrubs and trees). The species richness of the shrub layer increased with decreasing values of δ13C. Low soil P availability thus affects local species richness in the matorral shrub-lands of Patagonia in Argentina although the growth of vegetation in the area has been shown to be limited by N. We suggest that low P levels increase plant species richness because low soil P concentration is associated with a high P partitioning and high potential for niche separation.
Sammendrag
Low soil temperatures limit nutrient uptake with negative consequences for growth and foliage quality. A better understanding of the temperature sensitivity of root N uptake is required to improve the best management practices for fertilization of conifers. Uptake of 15N in saplings of Abies lasiocarpa (Hook) Nutt and Abies nordmanniana (Steven) Spach was studied at root temperatures of 3 - 15°C in hydroponics. 15N accumulation in shoots increased with temperature, showing accelerated accumulation from 7°C upward. At 3°C, uptake rates were low for both species. Between 7 and 12°C, 15N accumulation in shoots increased by a factor of 5 in A. lasiocarpa and by a factor of 3 in A. nordmanniana. The temperature response of N uptake was similar to root growth responses to temperature documented by previous studies. The results have implications for early season fertilization, where fertilization of both species should be withheld until soil temperatures reach 10 -12°C.
Forfattere
Holger LangeSammendrag
Spatial dependencies among environmental variables are often quantified by spatial autocorrelation functions. The latter basically assume linearity and isotropy, requirements usually not satisfied for measured data. Typical symptoms of violated assumptions are biased parameter estimations. Relaxing the assumptions of linear dependencies and isotropy, we present a conceptual generalization of spatial analysis where locally varying anisotropies in the geographical space are uncovered by investigating nonlinear dependencies among observations. The framework is illustrated by generalizing two examples: distance decay relations and spatial filtering. The proposed alternative is based on geodesic ecological and anisotropic spatial distances.
Forfattere
Jan Alexander Augustine Arukwe Aksel Bernhoft Margaretha Haugen Åshild Krogdahl Jørgen Fr Lassen Audun Helge Nerland Bjørn Næss Janneche Utne Skåre Inger-Lise Steffensen Leif Sundheim Line Emilie Sverdrup Ole Torrissen Olav Østerås Gro Ingunn HemreSammendrag
Det er ikke registrert sammendrag
Forfattere
Helge SjursenSammendrag
Lodnefaks hører til den biologiske gruppen toårige. Den voksne planten er 25-90 cm høy med trevlerot. Hele planten er kledd med myke, gråhvite hår, og får derved et loddent utseende. Strået er nedliggende eller opprett, tynt eller forholdsvis kraftig. Bladene er 2-7 mm breie med 3 nerver, jevnt tilspisset, slappe og grågrønne. Slirehinnen er inntil 2,5 cm lang, hel, sjelden tannet. Bladører mangler. Bladsliren er rørformet, men sprekker snart opp. Blomstene sitter i en i topp med ca. 20 eggerunde småaks, hvert med 8-12 blomster. Toppen er åpen og opprett til å begynne med, seinere sammenklemt og nikkende. Formeringen og spredningen skjer utelukkende med frø. Lodnefaks lager bare en liten bladtust første året, men blomstrer og setter frø tidlig andre året. Forekommer i grasmark, åkerland, langs veikanter og på avfallsplasser. Liker tørr jord. Opptrer som ugras i frøeng, åker og beite. Arten var mye mer vanlig før enn nå, mest i engen – særlig i kyststrøk på Sør- og østlandet. Finnes nå mest bare på avfallsplasser hist og her. Lodnefaks (som rugfaks) kan motarbeides ved å hindre frøspredning og ved bruk av reine såvarer og ugrasrein gjødsel – dessuten ved tidlig slått av engen.