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.
2017
Sammendrag
På grunn av uventa avlingssvikt i jordbær forårsaket av gråskimmel på Sørlandet i 2016, ble det tatt ut prøver fra 20 jordbærfelt i Agder etter høsting for å undersøke mulig resistensforekomst hos gråskimmelsoppen mot kjemiske soppmidler. Totalt ble 148 til 157 soppisolater fra 19 felt analysert for resistens mot alle de kjemiske gruppene av virksomme stoffer som brukes mot gråskimmel; boskalid (SDHI), fenheksamid (hydroksyanilid), iprodion (dikarboksimid), pyrimetanil (anilinopyrimidin) og pyraklostrobin (QoI/strobilurin). Vi fant at 89,7, 86,0 og 65,0 % av isolatene var resistente mot henholdsvis boskalid, pyraklostrobin og fenheksamid. Videre var 25,0 % resistente mot pyrimetanil og 2,6 % resistente mot iprodion, mens ingen av soppisolatene var resistente mot fludioksonil. Kun 8,9 % av soppisolatene var sensitive overfor alle de virksomme stoffene, mens 5,1 % var resistente mot ett stoff (kjemisk gruppe). De øvrige isolatene var multiresistente mot to (21,0 %), tre (43,9 %), fire (19,1 %) og fem (1,9 %) virksomme stoffer. Resulatene stemmer godt med tidligere funn både i Norge og andre land. Høy grad av resistens mot boskalid, fenheksamid og pyraklostrobin er alvorlig, fordi disse har vært svært viktige for å bekjempe gråskimmel i jordbær. Dårlig virkning av disse midlene kan gjøre bekjempelse av gråskimmel framover svært vanskelig for produsentene. Det er viktig å understreke at det var relativt stor variasjon i resistensforkomst mellom de ulike jordbærfeltene, og at det er mange andre faktorer i tillegg til resistens (som værforhold, sprøyteteknikk og dyrkingssystem) som vil påvirke hvor mye avlingstap gråskimmel forårsaker.
Forfattere
Erling Meisingset Leif Egil Loe Øystein Brekkum Richard Bischof Inger Maren Rivrud Unni Støbet Lande Barbara Zimmermann Vebjørn Veiberg Atle MysterudSammendrag
1. Population-level management is difficult to achieve if wildlife routinely crosses administrative boundaries, as is particularly frequent for migratory populations. However, the degree of mismatch between management units and scales at which ecological processes operate has rarely been quantified. Such insight is vital for delimiting functional population units of partially migratory species common in northern forest ecosystems. 2. We combined an extensive dataset of 412 GPS-marked red deer (Cervus elaphus) across Norway with information on the size and borders of two administrative levels, the governmental level (municipality) and landowner level (local management units, LMUs), to determine the timing and scale of mismatch between animal space use and management units. We analysed how landscape characteristics affected the use of management units and the timing and likelihood of crossing borders between them, in an effort to delineate more appropriate units in various landscapes. 3. Median municipality size could potentially cover 70% of female and 62% of male annual ranges, while only 12% and 4% of LMUs were expansive enough to accommodate migratory routes in females and males, respectively. Red deer migrate along elevational gradients and are more likely to find both suitable lowland winter habitat and higher summer habitat within management units with variable topography. Consistent with this, the likelihood of border crossing decreased with increasing diversity of elevations. 4. Synthesis and applications. We demonstrate a considerable mismatch between animal space use and management units. Far-ranging movements and frequent administrative border crossings during autumn migration coincides with the period of active management (hunting season). Our study also highlights that, due to extensive movements of males, coordination of management aims may provide a more realistic avenue than increasing sizes of local management units. A more general insight is that the degree of mismatch between range use and management units depends on the season and landscape type. This needs to be accounted for when delimitating functional population units of migratory populations.
Forfattere
Shota Masumoto Masaki Uchida Motoaki Tojo Maria-Luz Herrero Akira S. Mori Satoshi ImuraSammendrag
In Arctic tundra, plant pathogens have substantial effects on the growth and survival of hosts, and impacts on the carbon balance at the scale of ecological systems. To understand these effects on carbon dynamics across different scales including plant organ, individual, population and ecosystem, we focused on two primary factors: host productivity reduction and carbon consumption by the pathogen. We measured the effect of the pathogen on photosynthetic and respiratory activity in the host. We also measured respiration and the amount of carbon in the pathogen. We constructed a model based on these two factors, and calculated pathogenic effects on the carbon balance at different organismal and ecological scales. We found that carbon was reduced in infected leaves by 118% compared with healthy leaves; the major factor causing this loss was pathogenic carbon consumption. The carbon balance at the population and ecosystem levels decreased by 35% and 20%, respectively, at an infection rate of 30%. This case study provides the first evidence that a host plant can lose more carbon through pathogenic carbon consumption than through a reduction in productivity. Such a pathogenic effect could greatly change ecosystem carbon cycling without decreasing annual productivity.
Forfattere
Shuxin Han Yanling Gao Guoquan Fan Wei Zhang Cailing Qiu Shu Zhang Yanju Bai Junhua Zhang Carl Jonas Jorge SpetzSammendrag
This study reports the findings of a distinct Potato virus Y (PVY) isolate found in Northeast China. One hundred and ten samples (leaves and tubers) were collected from potato plants showing mosaic symptoms around the city of Harbin in Heilongjiang province of China. The collected tubers were planted and let to grow in a greenhouse. New potato plants generated from these tubers showed similar symptoms, except for one plant. Subsequent serological analyses revealed PVY as the causing agent of the disease. A novel PVY isolate (referred to as HLJ-C-44 in this study) was isolated from this sample showing unique mild mosaic and crisped leaf margin symptoms. The complete genome of this isolate was analyzed and determined. The results showed that HLJ-C-44 is a typical PVY isolate. Phylogenetic analysis indicated that this isolate belongs to the N-Wi strain group of PVY recombinants (PVYN-Wi) and also shared the highest overall sequence identity (nucleotide and amino acid) with other members of this strain group. However, recombination analysis of isolate HLJ-C-44 revealed a recombination pattern that differed from that of other PVYN-Wi isolates. Moreover, biological assays in four different potato cultivars and in Nicotiana tabacum also revealed a different phenotypic response than that of a typical PVYN-Wi isolate. This data, combined, suggest that HLJ-C-44 is a novel PVY recombinant with distinct biological properties.
Forfattere
Hans Petersson Johannes Breidenbach David Ellison Sören Holm Anders Muszta Mattias Lundblad Göran R. StåhlSammendrag
Many parties to the United Nation's Framework Convention on Climate Change (UNFCCC) base their reporting of change in Land Use, Land-Use Change and Forestry (LULUCF) sector carbon pools on national forest inventories. A strong feature of sample-based inventories is that very detailed measurements can be made at the level of plots. Uncertainty regarding the results stems primarily from the fact that only a sample, and not the entire population, is measured. However, tree biomass on sample plots is not directly measured but rather estimated using regression models based on allometric features such as tree diameter and height. Estimators of model parameters are random variables that exhibit different values depending on which sample is used for estimating model parameters. Although sampling error is strongly influenced by the sample size when the model is applied, modeling error is strongly influenced by the sample size when the model is under development. Thus, there is a trade-off between which sample sizes to use when applying and developing models. This trade-off has not been studied before and is of specific interest for countries developing new national forest inventories and biomass models in the REDD+ context. This study considers a specific sample design and population. This fact should be considered when extrapolating results to other locations and populations.
Sammendrag
Changes in forest management have been suggested as a government policy to mitigate climate change in Norway. Tree species change is one of the major strategies considered, with the aim to increase the annual uptake of CO2 as well as the long-term storage of carbon (C) in forests. The strategy includes replacing native, deciduous species with fast-growing species, mainly Norway spruce. Forests in western Norway host some of the largest soil C pools in Scandinavia, and may potentially function as a long-term C reservoir as well as a large source of atmospheric CO2 through decomposition. The project BalanC was initiated in 2016 in order to estimate the C storage potential related to tree species in a total of 15 parallel plots of birch and planted Norway spruce at 5 locations in western Norway. In addition to estimates of C stocks in biomass and soils, we investigate soil C processes, soil fungal and earthworm diversity, albedo, and wood product life-cycles. The current presentation focuses on C stocks in soils relative to trees, soil respiration, and soil climate data. Preliminary results indicate that the soil respiration in spruce was 85 % of the respiration in birch, with a span ranging from 55-151%. The preliminary soil temperature and soil moisture data of the spruce stands were 97 and 73%, respectively, of the birch stands, indicating cooler and drier conditions under spruce which may affect decomposition and C accumulation rates. We expect C allocation in the soil to be affected by tree species, with larger C stocks in the forest floor of spruce stands compared to the mineral soil. Consistent differences in the bulk density of soils under each tree species are likely to be observed, pointing out the need to compare soil C stocks based on equal soil mass. The magnitude of the combined C stock in biomass and soil may increase with planting of spruce, however, we also expect an impact on C stability that will affect the overall mitigation effect of this measure.
Sammendrag
Phenological observations are considered to be sensitive tools for identifying plant responses to climatic changes. Over the last 10 years, the onset of the phenophases of sweet cherry (Prunus avium L.) during spring tended to be earlier than the previous two decades in Ullensvang, western Norway. The effects of air temperature during the winter and spring months were evaluated during two quinquennia (5-year periods), 1996-2000 (Q1) and 2003-2007 (Q2) selected due to similar mean winter and early summer temperatures, but markedly different spring temperatures. Average January-February temperatures were similar (3.3°C) in both of these two 5-year periods. However, average March and April temperatures were slightly warmer (4.0 vs. 3.2°C) and (7.3 vs. 6.9°C), respectively, in Q2 vs. Q1. These increases resulted in significantly earlier flower development. Average temperatures during the first half of May were similar for both quinquennia (10.2 vs. 10.1°C). The start of flowering (first bloom) of early maturing ‘Burlat’ and mid-season ‘Van’ were significantly different. Timing of flowering phenophases were statistically different between Q1 and Q2 for both cultivars. Mean data for ‘Burlat’ and ‘Van’ first bloom were 8 days earlier during Q2, May 2 for ‘Burlat’ and May 1 for ‘Van’. Full bloom occurred 3 days after first bloom and flowering ended 14 days after first bloom. First bloom during Q2 required 221 Baskerville-Emin Growing degree days (GDD) using a base temperature of 2°C. For the same time period in Q1, only 197 GDD were accumulated, which supports the observed temperature differences. Furthermore, we propose a flowering model for full bloom of both ‘Burlat’ and ‘Van’ in Ullensvang, which requires 254 Baskerville-Emin GDD using a base of 2°C starting on March 1.
Forfattere
Anna Kårlund Kati Hanhineva Marko Lehtonen Gordon J. McDougall Derek Stewart Reijo O. KarjalainenSammendrag
BACKGROUND: The non-edible parts of horticultural crops, such as leaves, contain substantial amounts of valuable bioactive compounds which are currently only little exploited. For example, strawberry (Fragaria × ananassa) leaves may be a promising bioresource for diverse health-related applications. However, product standardization sets a real challenge, especially when the leaf material comes from varying cultivars. The first step towards better quality control of berry fruit leaf-based ingredients and supplements is to understand metabolites present and their stability in d ifferent plant cultivars, so this study surveyed the distribution of potentially bioactive strawberry leaf metabolites in six different strawberry cultivars. Non-targeted metabolite profiling analysis using LC/qTOF-ESI-MS with data processing via principal component analysis and k-means clustering analysis was utilized to examine differences and commonalities between the leaf metabolite profiles. RESULTS: Quercetin and kaempferol derivatives were the dominant flavonol groups in strawberry leaves. Previously described and novel caffeic and chlorogenic acid derivatives were among the major phenolic acids. In addition, ellagitannins were one of the distinguishing compound classes in strawberry leaves. In general, strawberry leaves also contained high levels of octadecatrienoic acid derivatives, precursors of valuable odour compounds. CONCLUSION: The specific bioactive compounds found in the leaves of different strawberry cultivars offer the potential for the selection of optimized leaf materials for added-value food and non-food applications.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Caroline Brophy John A. Finn Andreas Lüscher Matthias Suter Laura Kirwan Maria-Teresa Sebastià Áslaug Helgadóttir Ole Hans Baadshaug Gilles Bélanger Alistair Black Rosemary P. Collins Jure Čop Sigridur Dalmannsdottir Ignacio Delgado Anjo Elgersma Michael Fothergill Bodil E. Frankow-Lindberg An Ghesquiere Barbara Golinska Piotr Golinski Philippe Grieu Anne-Maj Gustavsson Mats Höglind Olivier Huguenin-Elie Marit Jørgensen Zydre Kadziuliene Päivi Kurki Rosa Llurba Tor Lunnan Claudio Porqueddu Ulrich Thumm John ConnollySammendrag
1. Increased species diversity promotes ecosystem function; however, the dynamics of multi-speciesgrassland systems over time and their role in sustaining higher yields generated by increased diver-sity are still poorly understood. We investigated the development of species’ relative abundances ingrassland mixtures over 3 years to identify drivers of diversity change and their links to yield diver-sity effects.2. A continental-scale field experiment was conducted at 31 sites using 11 different four-speci esmixtures each sown at two seed abundances. The four species consisted of two grasses and two legumes, of which one was fast establishing and the other temporally persistent. We modelledthe dynamics of the four-species mixtures, and tested associations with diversity effects on yield.3. We found that species’ dynamics were primarily driven by differences in the relative growth rates(RGRs) of competing species, and secondarily by density dependence and climate. The temporallypersistent grass species typically had the highest RGRs and hence became dominant over time. Den-sity dependence sometimes induced stabilising processes on the dominant species and inhibitedshifts to monoculture. Legumes persisted at most sites at low or medium abundances and persistencewas improved at sites with higher annual minimum temperature.4. Significant diver sity effects were present at the majority of sites in all years and the strength ofdiversity effects was improved with higher legume abundance in the previous year. Observed diver-sity effects, when legumes had declined, may be due to (i) important effects of legumes even at lowabundance, (ii) interaction between the two grass species or (iii) a store of N because of previouspresence of legumes.5. Synthesis. Alongside major compositional changes driven by RGR differences , diversity effectswere observed at most sites, albeit at reduced strength as legumes declined. This evidence stronglysupports the sowing of multi-species mixtures that include legumes over the long-standing practiceof sowing grass monocultures. Careful and strategic selection of the identity of the species used inmixtures is suggested to facilitate the maintenance of species diversity and especially persistence oflegumes over tim e, and to preser ve the strength of yield increases associated with diversity.