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.
2020
Forfattere
Camilla Lorange Lindberg Hans Martin Hanslin Marian Schubert Thomas Marcussen Ben Trevaskis Jill Christine Preston Siri FjellheimSammendrag
Semelparous annual plants flower a single time during their 1‐yr life cycle, investing much of their energy into rapid reproduction. By contrast, iteroparous perennial plants flower multiple times over several years, and partition their resources between reproduction and persistence. To which extent evolutionary transitions between life‐cycle strategies are internally constrained at the developmental, genetic and phylogenetic level is unknown. Here we study the evolution of life‐cycle strategies in the grass subfamily Pooideae and test if transitions between them are facilitated by evolutionary precursors. We integrate ecological, life‐cycle strategy and growth data in a phylogenetic framework. We investigate if growth traits are candidates for a precursor. Species in certain Pooideae clades are predisposed to evolve annuality from perenniality, potentially due to the shared inheritance of specific evolutionary precursors. Seasonal dry climates, which have been linked to annuality, were only able to select for transitions to annuality when the precursor was present. Allocation of more resources to above‐ground rather than below‐ground growth is a candidate for the precursor. Our findings support the hypothesis that only certain lineages can respond quickly to changing external conditions by switching their life‐cycle strategy, likely due to the presence of evolutionary precursors.
Forfattere
Kjetil FadnesSammendrag
Gjennom tildelingsbrev frå LMD har NIBIO fått i oppdrag å utvikle rapporteringssystem for jordvernpolitikken. Som ledd i dette har vi undersøkt korleis ein kan koble ferske kartdata for bygningar og vegar mot AR5 for å gje eit estimat på årleg nedbygging av dyrka jord. Resultata tilseier at det er mogleg å gjennomføre årlege beregningar som fanger opp ein stor del av utbygginga, men at det er noko usikkerheit knytta til metoden. Det vert pekt på nokre tiltak for å forbetre metoden og gje tal på usikkerheit knytt til estimatet. Det vert også pekt på måtar å få fram konsekvensar for matproduksjon og økosystemtenester.
Sammendrag
«Landbruk over hele landet» er et av fire hovedmål i norsk landbrukspolitikk. Denne rapporten dokumenterer et forsøk på å utvikle en metode for å kvantifisere måloppnåelse på dette området. Forsøket er begrenset til jordbruket, og vi har valgt fire binære indikatorer på delområdenivå. Indikatorene formidler hvorvidt et område oppfyller ulike, på forhånd definerte minstekrav. Indikatorene er i) antall aktive jordbruksbedrifter, ii) andel aktive søkere i forhold til alle registrerte landbrukseiendommer, iii) bruk av utmarksressursene og iv) jordbruksareal i drift. Basert på disse indikatorene beregnes en indeks som kan gi grunnlag for en samlet vurdering av måloppnåelsen. Resultatene viser store forskjeller i de ulike regionene, med Trøndelag på topp og Nord-Norge på bunn.
Sammendrag
Innføring av obligatorisk individmerking av tamrein i Norge ble vedtatt av Stortinget 13. juni 2019. NIBIO har i denne rapporten belyst hvilke merkemetoder for individmerking som finnes på markedet i dag og hvordan disse egner seg for bruk i reindrifta. Kunnskap om disse og individmerking generelt i næringa, forvaltningen og reindriftsmyndighetene er innhentet gjennom utstrakt kontakt med en rekke informanter. Mulighetene og utfordringene som ligger i individmerking for næring, forvaltning og myndigheter er undersøkt og kartlagt. NIBIO har belyst en del punkter som anbefales for veien videre vedrørende innføring av individmerking i reindriften. NIBIO har også foreslått pilotprosjekter som kan/bør gjennomføres for å forberede reindriften på innføring av individmerking, samt forbedrer dagens løsninger for elektronisk individmerking slik at disse blir driftssikre, kostnadslave, møter næringens behov og nytte og samtidig gir myndigheter og forvaltning ny kunnskap om Norges tamrein...
Forfattere
Joana Carvalho Cachapa Nicolai Vitt Meyling Meike Burow Thure Pavlo HauserSammendrag
Plants evolved in close contact with a myriad of microorganisms, some of which formed associations with their roots, benefitting from carbohydrates and other plant resources. In exchange, they evolved to influence important plant functions, e.g. defense against insect herbivores and other antagonists. Here, we test whether a fungus, Metarhizium brunneum, which is mostly known as an insect pathogen, can also associate with plant roots and contribute to above-ground plant defense. Cauliflower (Brassica oleracea var. botrytis) seeds were sown together with M. brunneum-inoculated rice grains, and the resulting plants subjected to leaf herbivory by the specialist Plutella xylostella. Activity of myrosinases, the enzymes activating glucosinolates, was measured before and after herbivory; larval consumption and plant weight at the end of experiments. Metarhizium brunneum clearly established in the plant roots, and after herbivory myrosinase activity was substantially higher in M. brunneum-treated plants than in controls; before herbivory, M. brunneum-treated and control plants did not differ. Leaf consumption was slightly lower in the M. brunneum-treated plants whereas total biomass and allocation to above- or below-ground parts was not affected by the Metarhizium treatment. Thus, M. brunneum associates with roots and primes the plant for a stronger or faster increase in myrosinase activity upon herbivory. Consistent with this, myrosinase function has been suggested to be rate-limiting for induction of the glucosinolate-myrosinase defense system. Our results show that M. brunneum, in addition to being an insect pathogen, can associate with plant roots and prime plant defense.
Sammendrag
In the Nordic countries Finland, Norway and Sweden, the most common regeneration method is planting after clearcutting and, often, mechanical site preparation (MSP). The main focus of this study is to review quantitative effects that have been reported for the five main MSP methods in terms of survival and growth of manually planted coniferous seedlings of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) in clearcuts in these three countries. Meta analyses are used to compare the effects of MSP methods to control areas where there was no MSP and identify any relationships with temperature sum and number of years after planting. In addition, the area of disturbed soil surface and the emergence of naturally regenerated seedlings are evaluated. The MSP methods considered are patch scarification, disc trenching, mounding, soil inversion and ploughing. Studies performed at sites with predominately mineral soils (with an organic topsoil no thicker than 0.30 m), in boreal, nemo-boreal and nemoral vegetation zones in the three Fenno-Scandinavian countries are included in the review. Data from 26 experimental and five survey studies in total were compiled and evaluated. The results show that survival rates of planted conifers at sites where seedlings are not strongly affected by pine weevil (Hylobius abietis L.) are generally 80–90% after MSP, and 15–20 percent units higher than after planting in non-prepared sites. The experimental data indicated that soil inversion and potentially ploughing (few studies) give marginally greater rates than the other methods in this respect. The effects of MSP on survival seem to be independent of the temperature sum. Below 800 degree days, however, the reported survival rates are more variable. MSP generally results in trees 10–25% taller 10–15 years after planting compared to no MSP. The strength of the growth effect appears to be inversely related to the temperature sum. The compiled data may assist in the design, evaluation and comparison of possible regeneration chains, i.e. analyses of the efficiency and cost-effectiveness of multiple combinations of reforestation measures.
Forfattere
Lars Olav Brandsæter Kjell Mangerud Lars Andersson Trond Børresen Guro Brodal Bo MelanderSammendrag
There is a need both in organic farming and on farms using integrated pest management for non-chemical measures that control the perennial weed flora. The effect of mechanical weeding and fertilisation on perennial weeds, fungal diseases and soil structure were evaluated in two different experiments in spring cereals. Experiment I included six strategies. The first strategy was (1) without specific measures against perennial weeds. The other strategies encompassed one or two seasonal control measures; (2) rhizome/root cutting with minimal soil disturbance in autumn, (3) hoeing with 24 cm row spacing, (4) combined hoeing and disc harrowing in autumn, (5) ‘KvikUp’ harrowing in spring, and (6) ‘KvikUp’ harrowing in spring and autumn. Experiment II included factor (i) inter-row hoeing and (ii) fertilisation level. This experiment included the comparison between normal row spacing (12 cm) with weed harrowing versus double row spacing (=24 cm) in combination with inter-row hoeing and 4 fertilisation levels (50–200 kg N ha−1). In experiment I the strategies consisting of no or one direct weed control measure (1, 2, 3 and 5) clearly did not control the perennial weeds. The two seasonal control measures (4 and 6) gave a satisfactory weed control and highest crop yield. The combination of best weed control and no measured harmful effects on soil structure or increase of fungal diseases may explain the highest yields for these strategies. In Experiment II, hoeing and 24 cm spacing gave less perennial biomass compared to 12 cm spacing. Grain yields increased linearly with increasing nitrogen input. The study shows that both inter-row hoeing and weed harrows, are important elements in integrated pest management practice and organic farming. In addition, our results indicate that efficient mechanical weeding is possible without harmful effects in crop rotation consisting of various spring cereals as regards soil structure and plant health.
Sammendrag
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Sammendrag
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Sammendrag
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