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
In Norway, Nordmann (Abies nordmanniana) and subalpine fir (A. lasiocarpa) are the dominant Christmas tree species and Noble fir (A. procera) the dominant species for bough production. In the spring of 2005 a survey was undertaken to determine the presence of fungi on seeds of these three plant species. Twelve seed samples were tested; five from Nordmann fir, four from subalpine fir and three from Noble fir. The test included seeds produced in Austria (Nordmann fir), Canada (subalpine fir), Georgia (Nordmann fir), Norway (Noble and subalpine fir) and Russia (Nordmann fir). The testing was done in a certified seed laboratory in Norway. One hundred seeds per sample were pre-treated in 1 % NaOCl and plated on potato dextrose agar (PDA), and 100 seeds per sample were pre-treated in H2O2 and plated on water agar (WA). The PDA Petri dishes were incubated for 5 to 7 days at 20 + 2 ºC and the WA Petri dishes for 15 to 19 days at 15 + 2 ºC, both under alternating 12 h NUV-light and 12 h darkness. To date not all of the fungi have been identified, but fungi from several genera have been found: Alternaria, Anthostomella, Aspergillus, Aureobasidium, Botrytis, Caloscypha, Cephalosporium, Chaetomium, Cladosporium, Dictyopolyschema, Epicoccum, Fusarium, Mucor, Penicillium, Phoma, Rhizopus, Trichoderma, and Trichothecium. Caloscypha was only found on one subalpine fir seedlot from Canada and Anthostomella on one subalpine fir seed from Norway. All the other fungi were more commonly found in all the samples. Fusarium species are well known to cause damping off in nurseries, but are not reported to cause problems in production fields. Species of Alternaria, Phoma, Botrytis and Trichothecium can damage seedlings. Anthostomella conorum is reported on cone scales of pine (Pinus spp.), but is not described as pathogenic. Aureobasidium is described as a saprophytic or weakly parasitic cosmopolitan fungal genus. Aureobasidium sp. is commonly found in Norway on buds of subalpine fir which fail to open in spring, and it will therefore be included in a pathogenicity test.
Forfattere
Trygve S. Aamlid Arild Andersen Rolf Skuterud Gunvald Henning JonassenSammendrag
The application of insecticides and / or chemical growth regulators for the control of arthropod-induced silvertops (whitetops) and / or lodging in seed crops of common bent (syn. browntop, US: colonial bentgrass, Agrostis capillaris L. syn. A.tenuis Sibth.) `Leikvin" was investigated in twelve on-farm trials laid out according to five different experimental plans in SE Norway from 1993 through 1997. Seed yields on plots sprayed with insecticides were significantly higher than on unsprayed control plots in three out of nine trials, however, these seed yield increases were poorly correlated with silvertop frequencies which varied from 1 to 60% on untreated plots. Differences between various insecticides (two pyretroids and one organophosphorous compound) and single versus split applications were mostly not significant. While seed yields on plots sprayed with ethephone ("Cerone", 0.5 kg a.i. ha-1) were not significantly different from those on unsprayed control plots, chlormequat chloride ("CCC 750", 1.0 or 2.0 kg a.i. ha-1 plus surfactant) minimised lodging and increased seed yield by 21% on average for five trials. When chlormequat chloride and the pyretroid alphacypermethrin were combined in a tank mixture including surfactant at Z 31-32, the effects of the two products were mostly additive. Based on these results, the application of the growth regulator chlormequat chloride (1.0 kg a.i. ha-1) is now recommended in Norwegian seed production of common bent. Although the effects of insecticides were often not significant, seed growers are further advised to add an insecticide (e.g. alphacypermethrin, 150 g a.i. ha-1) to the growth regulator as a precaution against silvertops, which otherwise seem to strike quite randomly in seed production of common bent.
Forfattere
Oleg I. Shumilov Elena A. Kasatkina Paul E. Aspholm Natalia V. Lukina I. Yu. KirtsideliSammendrag
Records of growth rings in sub-arctic trees play an important role in reconstructing climate change in the past. Tree-ring chronologies collected from different parts of Arctic (Fennoscandia, Kola Peninsula and Northern Siberia) were investigated by spectral (MTM method) and wavelet analysis. Among them it was analyzed juniper tree ring chronology with extension more than 700 years (from about 1300 A.D. till 2004 A.D.) collected for the central part of Kola Peninsula (Keivy region: 67.77N; 36.52E). Results of spectral analysis allow us to select the main periods of solar variability (22-year, 30-33 year and 80-90-year solar cycles) in Kola and Fennoscandia tree-ring chronologies. Besides it was found that only periodicities of around 20 years are present in Siberian series. With respect to 11-year periodicity, which is the most prominent one in sunspot number spectrum (Schwabe cycle) it may be said that it hardly appeared in sub-arctic tree-ring records. It was obtained a rather good correlation between long-term climatic variation in Europe and at Kola Peninsula. The minima of solar activity during the Sporer (1416-1534 AD), Maunder (1645-1715 AD) and Dalton (1801-1816 AD) were accompanied by temperature decreases. The coldest conditions of the last 700 years in the Northern Europe were in the XVII century during the "Little Ice Age" period. It should be noted that the Kola Peninsula tree-ring chronologies analysed here did not show any extended growth at the end of the XX century. The result obtained give us information on local climate variations in the very important area influenced by Gulf Stream and Arctic ocean and located in the vicinity of the very important for whole Europe gas field at the shelf of Barents sea. The work was partially supported by the program "Biodiversity and dynamics of gene pool" of the Russian Academy and by RFBR grant N 05-04-97528.
Forfattere
J. Derome P.A. Aarrestad P. Aspholm V. Bakkestuen J.W. Bjerke K.E. Erikstad M. Hartikainen L. Isaeva M. Lindgren A.-J. Lindroos T. Myking J. Poikolainen P. Rautio I. Røsberg M. Salemaa H. Tømmervik N. VassilievaSammendrag
This report describe the results of the monitoring , research, evaluation and development activities carried out within the Interreg IIIA Kolarctic project "Development and implementation of an environmental monitoring and assessment system in the joint Finnish, Norwegian and Russian border area" during the periode 2003-2006.The results of these activities form a basis for the development of a joint environmental monitoring programme in the border areabetween Norway, Finland and Russia. The report gives an overall view of the environmental condition in the Paz (Pasvik) River basinand of the changes that have taken place over the last decade as a result of emissions from the mining and metallurgical plant at Pechenganikel (Nikel and Zapolyarnyi), located in theimmediate vicinity of the border areas between Russia and Norway and Finland. The primary objectives of this part of the project were to integrate and harmonise the monitoring activities that have already been carried out by Norway, Russia and Finland on the effects of emissions from the Pechenganikel smelter on terrestrial ecosystems in the border area, and to identify relatively sensitive and cost-effective parameters for future monitoring activities in the area. In order to fulfil these objectives, a terrestrial ecosystem monitoring network (TECM) was established in Norway, Russia and Finland on the basis of existing monitoring networks.
Sammendrag
Simple risk assessment tools for agricultural phosphorus (P) losses, like the P index, have been developed in the U.S.A. and in some European countries. Despite its popularity, there have been surprisingly few studies, which try to test the index close to the field scale. For Norway, the P index approach comprises the risk related to both the source of P (soil P status, amount of fertilizer and manure as well as method of application, plant P release by freezing and P balance) and the risk related to transport of P (erosion, flooding, surface runoff, contributing distance, modified connectivity, soil profile, subsurface drainage). In this paper, we have applied the Norwegian P index to farmer fields within a small agricultural catchment, the Skuterud catchment (450 ha), in southeastern Norway. The Norwegian P index was tested for two agricultural fields (0.3 to 0.4 ha) and nine subcatchments (6 to 65 ha). Total P concentrations in runoff from the eleven study areas were measured during the year from May 2001 to April 2002. Results from the testing showed that the Norwegian P index described 66% of the variation in measured relative total P concentration for fields and subcatchments included in this study. Additionally, the P index was able to detect fields and subcatchments with the highest measured P concentrations. Results also showed that the source factor contributed most to the variation between fields and hence were important for the identification of high-risk areas in Skuterud catchment. It was found that the soil P status described 66% of the variation in the source factor. Among the transport variables, it was found that both erosion risk and contributing distance had an important influence on the transport factor. Overall, the study illustrated the potential of the P index to detect areas with the highest risk of P loss.
Sammendrag
Neozygites floridana is an important natural enemy of the two-spotted spider mite, Tetranychus urticae. Pesticides used in strawberries that might affect the conservation and enhancement of this beneficial fungus were therefore studied. This was done in a laboratory study by letting non-inoculated (healthy) mites and mites inoculated with N. floridana feed on strawberry leaf disks treated with one of the following pesticides: the fungicides tolylfluanid, fenhexamid or cyprodinil + fludioxonil or the acaricide/insecticide/molluscicide methiocarb. The effect of these pesticides on mortality and egg production of T. urticae and on the killing capacity and sporulation of N. floridana were determined. Tolylfluanid increased the mortality of non-inoculated mites (75.3%) compared to the non-inoculated control (27.5%). Methiocarb also killed non-inoculated mites. Fenhexamid did not have any effect on the mortality of non-inoculated mites (19.2%), neither had cyprodinil + fludioxonil (19.1%). Tolylfluanid did not reduce the mortality of mites inoculated with N. floridana (89.3%) compared to the inoculated control (80.0%). Neither did methiocarb, it rather increased the mortality of inoculated mites (93.2%). Fenhexamid did, however, reduce the mortality of inoculated mites (66.7%). The same was true for cyprodinil + fludioxonil (48.7%). In addition, cyprodinil + fludioxonil increased the time to death of inoculated mites (6.69 days) compared to the control (6.10 days), and inhibited sporulation of N. floridana (7.9% sporulation) compared to the control (42.4% sporulation). Tolylfluanid also reduced sporulation of N. floridana (15.5% sporulation). Results from this study indicate that the use of the fungicides tested will potentially reduce the survival and efficacy of the natural enemy N. floridana in the field.
Forfattere
Lars Tørres Havstad Trygve S. AamlidSammendrag
Tiller demography and contribution to seed yield were studied in first year seed crops of Bromus inermis `Løfar" and Festuca pratensis `Salten" planted on different dates and with increasing plant densities (A: 15 or 18 Jun / 11 plants m-2, B: 15 or 30 July / 44 plants m-2, C: 15 August or 10 September /178 plants m-2) in field trials at Landvik, SE Norway, in 1998 and 1999. While the total tiller population in most crops increased until seed harvest, it decreased during panicle elongation in crops of Bromus inermis and Festuca pratensis that had reached 2000 and 3500 tillers m-2 in early spring, respectively. Except for the fact that many of the primary tillers of Bromus inermis died after producing barren stems, tillers formed in August and September had the greatest chance of becoming reproductive and produced the longest culms with the heaviest inflorescences in both species. Most tillers produced in winter or early spring either remained vegetative or died, but spring-emerging tillers contributed up to 30% of the total seed yield in early-established, low-density crops of Festuca pratensis. The results are discussed in relation to former papers suggesting that inter-tiller transfer of flower induction stimuli is possible in some perennial grasses. It is concluded that tillers produced in winter and spring contribute more to seed yield in Festuca pratensis than in Bromus inermis.
Forfattere
M.B. Farmani H. Keers Nils-Otto KitterødSammendrag
Cross-well ground penetrating radar (GPR) data sets were collected in the vadose zone of an ice-contact delta near Oslo"s Gardermoen Airport (Norway) before, during, and after snowmelt in 2005. The observed travel times were inverted using curved-ray travel time tomography. The tomograms are in good agreement with the local geologic structure of the delta. The tomographic results were confirmed independently by surface GPR reflection data and x-ray images of core samples. In addition to structure, the GPR tomograms also show a strong time dependency due to the snowmelt. The time-lapse tomograms were used to estimate volumetric soil water content using Topp"s equation. The volumetric soil water content was also observed independently by using a neutron meter. Comparison of these two methods revealed a strong irregular wetting process during the snowmelt. This was interpreted to be due to soil heterogeneity as well as a heterogeneous infiltration rate. The geologic structure and water content estimates obtained from the GPR tomography can be used in forward and inverse flow modeling. Finally, the water balance in the vadose zone was calculated using snow accumulation data, precipitation data, porosity estimates, and observed changes in the groundwater table. The amount of water stored in the vadose zone obtained from the water balance is consistent with the amount estimated using GPR tomography. Alternatively, the change in water storage in the vadose zone can be estimated using GPR tomography. This may then permit estimates of evapotranspiration to be made, provided other components of the water balance are known.
Forfattere
Anne Kristine Søvik P.T. MørkvedSammendrag
Constructed wetlands (CWs) in the agricultural landscape reduce non-point source pollution through removal of nutrients and particles. The mechanisms contributing to removal of nitrogen (N) in CWs are considered to be sedimentation, assimilation in plants and microorganisms, and denitrification. Nitrogen assimilated in wetland vegetation will to a large extent be remineralized sooner or later, unless the vegetation is harvested. Thus, the most important removal mechanism for N and the only one which is permanent is microbial denitrification. Nitrogen removal in ponds is often found to be enhanced in the presence of plants, as denitrification is stimulation by supply of organic material from the plants, which may either be used directly by the denitrifying bacteria or indirectly by contributing to a lower redox potential. However, we still have a limited quantitative knowledge regarding the role of denitrification versus other processes in small CWs, and particularly how this shifts during the year. Biological discrimination between the two stable isotopes 14N and 15N leads to natural iso-topic fractionation, i.e., denitrification yields an enriched pool of 15NO3-, as bacteria preferentially reduce 14NO3- over 15NO3-. The isotopic signature has been used to identify regions of significant denitrification in e.g., groundwater aquifers, riparian buffer zones and CWs. As far as we know, the method has until now only been used in one study regarding constructed wetlands. More studies are needed to identify the limits and possibilities of this method in ecosystems such as CWs.
Forfattere
Anne-Grete Buseth BlankenbergSammendrag
In September 2000 EU agreed to implement the WFD. This led to some new perspectives in Norwegian administration. The areas of activity are watercourse/river systems, groundwater and sea-areas extending to one nautical mile outside the baseline. WFD are considered as a minimum requirement and every country are free to introduce more strict rules. The ministry of Environment are responsible for the coordination of the implementation of the Water Framework Directive in Norway. The government has delegated the responsibility to The Regional Commissioner "Fylkesmannsembetet". The first step in the WFD Implementation in Norway is to charaterize the catchment-areas and the water recipients in the nine Water regions. Based on todays situation, and the deviation from the expected natural state, the needs for and the extent of precautions will be identified to reach the environmental goals. Based on the water quality-quantity relations in the catchment areas / watershed, an action-plan will be pre-pared. The action-plan will ensure that the objectives will be fulfilled. Establishment of tar-gets and a monitoring program will be made for all the catchment areas / watershed. The tar-gets are planned to be reached within 15 Years (2015). To define a goal for water status, a water classification system are created. A GIS-tool has been made and distributed to all coun-ties for QA and input of additional regional/local information.