Hydrology influences breeding time in the white-throated dipper     

Nilsson  Anna L. K.  Skaugen  Thomas  Reitan  Trond  L’Abée-Lund  Jan Henning  Gamelon  Marlène  Jerstad  Kurt  Røstad  Ole Wiggo  Slagsvold  Tore  Stenseth  Nils C.  Vøllestad  L. Asbjørn  Walseng  Bjørn 《BMC ecology》2020,20(1):1-12

While nitrogen and carbon stable isotope values can reflect ecological segregation, prey choice and spatial distribution in seabirds, the interpretation of bulk stable isotope values is frequently hampered by a lack of isotopic baseline data. In this study, we used compound-specific isotope analyses of amino acids (CSIA-AA) to overcome this constraint and to study interspecific differences, seasonal and historical changes in trophic positions of five seabird species, three penguins and two petrels, from a sub-Antarctic seabird community. CSIA-AA allowed comparing trophic positions of seabirds with temperate and polar distributions. Gentoo and Magellanic penguins had the highest trophic positions during the breeding season (3.7 and 3.9), but decreased these (2.9 and 3.3) during the feed-up for moult. Intra-specific differences were also detected in Thin-billed prions, where carbon isotope values clearly separated individuals with polar and temperate distributions, both in the breeding and interbreeding periods. Thin-billed prions that foraged in polar waters had lower trophic positions (3.2) than conspecifics foraging in temperate waters (3.8). We further investigated historical changes by comparing museum samples with samples collected recently. Our pilot study suggests that Rockhopper penguins, Magellanic penguins and Thin-billed prions with temperate non-breeding distributions had retained their trophic levels over a 90–100 year period, while Gentoo penguins and Thin-billed prions with polar non-breeding distributions had decreased trophic levels compared to historical samples. In contrast, Wilson’s storm-petrels had slightly increased trophic levels compared to samples taken in 1924–1930. We applied compound-specific stable isotope analyses across a range of contexts, from intra-specific comparisons between stages of the breeding cycle to inter-specific seabird community analysis that would not have been possible using bulk stable isotope analyses alone due to differences in isotopic baselines.  相似文献   

History, manufacture and properties of lime bast cordage in northern Europe     

Myking  Tor; Hertzberg  Anja; Skroppa  Tore 《Forestry》2005,78(1):65-71

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Adaptive properties of Picea abies progenies are influenced by environmental signals during sexual reproduction     

Øystein Johnsen  Tore Skrøppa 《Euphytica》1996,92(1-2):67-71

Summary Several independent tests have shown that climate and weather during sexual reproduction influence the adaptive properties of the Picea abies progenies. This phenomenon is expressed in seed orchards established by moving parent trees, propagated as grafts, from north to south, from high to low elevation, or from outdoor to indoor greenhouse conditions. The progenies exhibit delayed flushing in the spring, later growth cessation of leader shoots in the summer, delayed bud-set, higher frequency of lammas shoots and delayed development of frost hardiness in the autumn compared to progenies reproduced in the colder native environment. The altered performance is persistent. We have found no effect on progenies of photoperiod and temperature treatments given to the males during meiosis and pollen production. However, when crosses were made in early spring (March), inside a heated greenhouse (short day, high temperature), the progenies are less frost hardy during cold acclimation than progenies from identical crosses performed in late spring (May; long day high temperature) in the greenhouse. The most hardy offspring were from crosses performed under outdoor conditions in May (long day, low temperature). These results indicate that some stages in reproduction, such as female meiosis, pollen tube growth, syngamy and early embryo development, are sensitive to temperature and/or photoperiod which then alter the phenotypic performance of the offspring. The most likely explanation is the existence of a regulatory mechanism affecting the expression of genes controlling adaptive traits. If this is true, it must have implications for the genetic interpretation of provenance differences in Norway spruce.  相似文献   

The N₂O product ratio of nitrification and its dependence on long-term changes in soil pH   总被引：1，自引：0，他引：1  

Pål Tore Mørkved  Peter Dörsch 《Soil biology & biochemistry》2007,39(8):2048-2057

The contribution of nitrification to the emission of nitrous oxide (N₂O) from soils may be large, but its regulation is not well understood. The soil pH appears to play a central role for controlling N₂O emissions from soil, partly by affecting the N₂O product ratios of both denitrification (N₂O/(N₂+N₂O)) and nitrification (N₂O/(NO₂⁻+NO₃⁻). Mechanisms responsible for apparently high N₂O product ratios of nitrification in acid soils are uncertain. We have investigated the pH regulation of the N₂O product ratio of nitrification in a series of experiments with slurries of soils from long-term liming experiments, spanning a pH range from 4.1 to 7.8. ¹⁵N labelled nitrate (NO₃⁻) was added to assess nitrification rates by pool dilution and to distinguish between N₂O from NO₃⁻ reduction and NH₃ oxidation. Sterilized soil slurries were used to determine the rates of chemodenitrification (i.e. the production of nitric oxide (NO) and N₂O from the chemical decomposition of nitrite (NO₂⁻)) as a function of NO₂⁻ concentrations. Additions of NO₂⁻ to aerobic soil slurries (with ¹⁵N labelled NO₃⁻ added) were used to assess its potential for inducing denitrification at aerobic conditions. For soils with pH?5, we found that the N₂O product ratios for nitrification were low (0.2-0.9‰) and comparable to values found in pure cultures of ammonia-oxidizing bacteria. In mineral soils we found only a minor increase in the N₂O product ratio with increasing soil pH, but the effect was so weak that it justifies a constant N₂O product ratio of nitrification for N₂O emission models. For the soils with pH 4.1 and 4.2, the apparent N₂O product ratio of nitrification was 2 orders of magnitude higher than above pH 5 (76‰ and 14‰). This could partly be accounted for by the rates of chemodenitrification of NO₂⁻. We further found convincing evidence for NO₂⁻-induction of aerobic denitrification in acid soils. The study underlines the role of NO₂⁻, both for regulating denitrification and for the apparent nitrifier-derived N₂O emission.  相似文献   

Earthworm channels in cultivated clayey and loamy Norwegian soils     

Tore E. Sveistrup  Trond Knapp Haraldsen  Freddy Engelstad 《Soil & Tillage Research》1997,43(3-4)

Studies of earthworm species and their activity, expressed as channels, on cultivated loamy (Humic Cryaquept) and clayey soils (Typic Endoaqualf and Typic Cryaquept) were conducted in southern and central Norway before conversion from conventional to organic cropping systems. At all the three study areas: Landvik (Grimstad), Voll (Ås) and Kvithamar (Stjørdal), the earthworm species Aporrectodea caliginosa, Aporrectodea rosea, Allolobophora chlorotica and Lumbricus rubellus were found. At Landvik, where the deep-burrowing species Aporrectodea longa, A. caliginosa and Lumbricus terrestris dominated, medium (4–6 mm) and coarse (>6 mm) earthworm channels were most numerous below the plough layer. Almost no coarse pores were found at Voll and Kvithamar. The volume of earthworm channels below the plough layer was 0.6–0.8% of total soil volume at Landvik and Voll and 0.3–0.4% at Kvithamar. Earthworm channels >6 mm below the plough layer were useful to identify present and previous activity of deep-burrowing earthworms such as L. terrestris. Below the plough layer, roots were almost entirely restricted to earthworm channels and interaggregate spaces.  相似文献   

Identification of Aerococcus Viridans by Means of Co-Agglutination     

Finn Saxegaard  Tore Hstein 《Acta veterinaria Scandinavica》1978,19(4):604

Gaffkemia, which has recently been reviewed by Stewart & Rabin (1970) and by Stewart (1975), is a fatal bacterial disease of the American and European lobster (Homarus americanus and Homarus vulgaris) (Snieszko & Taylor 1947). The causal agent, first classified as Gaffkya homari (Hitchner & Snieszko 1947), is now classified as Aerococcus viridans (Williams et aL 1953, Buchanan & Gibbons 1974).  相似文献   

Genetic diversity of Staphylococcus aureus isolated from ovine intramammary infections in Norway     

Mørk T  Tollersrud T  Kvitle B  Jørgensen HJ  Waage S 《Veterinary microbiology》2005,106(3-4):265-273

Three hundred and eighty-four Staphylococcus aureus isolates obtained from mammary secretions from 332 ewes kept for meat production were typed by pulsed-field gel electrophoresis (PFGE). The ewes were from 242 flocks located in 13 counties distributed in four regions of Norway. In total, 64 different pulsotypes were identified, 31 of these were represented by a single isolate. Fifty-nine percent of the isolates belonged to one of five closely related pulsotypes. This group of pulsotypes occurred in all the counties. Although widely disseminated, the proportions of the prevalent and closely related pulsotypes differed between the regions. Nine pulsotypes were unique to single regions but the number of isolates belonging to each of these pulsotypes was low. Resistance to penicillin was found in only 3 of the 384 S. aureus isolates. These represented three different single banding patterns, not related to any of the prevalent pulsotypes found.  相似文献   

Airborne Pollution in Five Drainage Basins in Eastern Finnmark, Norway: an Evaluation of Overbank Sediments as Sampling Medium for Environmental Studies and Geochemical Mapping     

Marianne Langedal  Rolf Tore Ottesen 《Water, air, and soil pollution》1998,101(1-4):377-398

To study whether airborne pollution can be detected in overbank sediments, samples collected from five overbank sediment profiles in eastern Finnmark, Norway, at 1 cm depth intervals, were subjected to chemical analysis and ²¹⁰Pb dating. The studied drainage basins constitute parts of an area polluted by emissions from two Ni-Cu smelters in Russia. In the most polluted catchment area, the surface sample showed a 5-fold higher Ni concentration and a 3-fold higher Cu concentration than the pre-industrial sediments at depth. The increases started at the same time as the smelters. Slight Ni increases were also detected in the neighbouring drainage basin, while no significant concentration change was seen in drainage basins previously shown to be only weakly influenced by the smelter emissions. In the most polluted drainage basin, the increase in Ni accumulation rate did not equal the airborne deposition rate. Selective surface erosion of fine grained particles with adhering airborne Ni has probably caused excess Ni accumulation in both overbank and lake sediments. On the contrary, opening of minerogenic point sources may dilute the pollutant concentrations in the drainage sediments. Thus, dating of the sediment profiles is necessary to determine the airborne pollutant accumulation rates. However, dating is not necessary to map the resultant concentration increase, that may show the increased exposure of humans and biota in contact with the sediments.  相似文献   

Long-term culture of Atlantic salmon (Salmo salar L.) in submerged cages during winter affects behaviour, growth and condition     

yvind J. Korsen  Tim Dempster  Per Gunnar Fjelldal  Frode Oppedal  Tore S. Kristiansen 《Aquaculture (Amsterdam, Netherlands)》2009,296(3-4):373-381

In the search for alternative farming methods, we investigated whether large salmon submerged below 10 m in winter conditions behaved normally and performed as well as control fish held in standard surface cages. On average, 2345 salmon of ~ 3.5 kg were kept in each of six 2000 m³ sea-cages for 6 weeks; three of which were submerged to 10–24 m depth and three acted as surface controls (0–14 m). Behaviour during both day and night was studied with echo-sounders, and underwater video cameras fitted with infra-red lamps. A sub-sample of fish from each cage was weighed, measured and assessed for fin and snout condition prior to and after the experimental period. In addition, the vertebral column of 50 fish from the control and submerged treatments were dissected and X-rayed to assess vertebral deformities. The submerged salmon seemed unable to re-fill any gas into the swim bladder, as a linear decrease in echo reflection to < 5% of pre-submergence levels after 22 days of submergence indicated loss of almost all gas from the physostomous swim bladders and negatively buoyant fish. Around day 22, submerged salmon swam at night time with a distinct ‘tail-down, head-up’ tilt (26°) compared to the horizontal swimming position of control fish (− 3°). Average swimming speed (body length per second) of submerged salmon were 1.3–1.4 times faster (day: 0.77 ± 0.02; night: 0.46 ± 0.02, (mean ± SE)) than control fish (day: 0.54 ± 0.01; night: 0.37 ± 0.02) both during day and night. Almost no mortality was seen, and the submerged salmon maintained similar diurnal vertical migrations as the surface fish, indicating that deep submergence did not exhaust the fish. However, submerged fish fed less efficiently, resulting in lower growth and reduced feed utilization. Fins and snouts of the submerged fish had small, but significantly more erosion than the control fish. Vertebrae in the tail region were significantly compressed in the submerged fish compared to control fish. This could be an early symptom of development of vertebral deformities. The results suggest that continuous submergence below 10 m for longer than 2 weeks reduces the welfare and performance of Atlantic salmon.  相似文献   

<Emphasis Type="Italic">Colletotrichum acutatum</Emphasis> occurs asymptomatically on sweet cherry leaves     

Jorunn Børve  Rolf Tore Djønne  Arne Stensvand 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(3):325-332

Leaves of sweet cherry, exposed to either paraquat or freezing to quickly senesce the leaf tissue, were incubated in about 100% RH at 25°C for 6 d. Sporulating colonies of Colletotrichum acutatum, the cause of anthracnose, developed on up to 100% of the paraquat-treated and frozen leaves, and on none of the untreated controls. Number of leaves and leaf area containing C. acutatum on naturally infected leaves increased over time from May to September. Mean incidence of C. acutatum on leaf blades on fruit spurs and vegetative shoots from eight orchard/year samplings were 41 and 33%, respectively. Secondary conidiation (formation of short hyphae and new conidia) from conidia applied to detached leaves took place 6 h after inoculation, but only up to 3% of the conidia formed new conidia. It may be concluded that asymptomatic sweet cherry leaves frequently host C. acutatum and may be a potential inoculum source for cherry fruit.  相似文献