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
Tomasz Leszek WoznickiSammendrag
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Sammendrag
Key message This literature review identified the main factors for the success of different silvicultural approaches to regenerate sessile oak naturally and unveiled at the same time important knowledge gaps. Most previous studies were only short-term and restricted to a few factors and single locations. Hence, the findings of these studies are of limited explanatory power and do not allow to develop general, widely applicable management recommendations. Context Successful natural regeneration of sessile oak (Quercus petraea (Matt.) Liebl.) through silvicultural actions depends on a number of biotic, abiotic and management factors and their interactions. However, owing to a limited understanding about the influence of these critical factors, there is great uncertainty about suitable silvicultural approaches for natural oak regeneration, in particular regarding the size of canopy openings and speed of canopy removal. Aims This study aimed at critically evaluating documented information on natural regeneration of sessile oak. Specifically, we identified (i) the factors that determine the success of approaches for natural regeneration and (ii) evaluated the evidence base associated with different silvicultural approaches. Methods A comprehensive literature search was done considering relevant peer-reviewed publications of ISI-listed journals as well as non-ISI listed published papers and reports by practitioners. Out of more than 260 collected references, a set of 53 silvicultural ‘core publications’ was identified and analyzed using a catalogue of numeric and categorical evaluation criteria. Results The most important factors determining regeneration success extracted from the literature were light availability, presence of competing vegetation, initial oak seedling density, browsing of seedlings and intensity of stand tending measures. However, the review revealed also great uncertainty regarding the interactions between these factors and the magnitude of their influence. Most studies were of short duration and restricted to single locations. In only 20% of the experimental studies, the observation period exceeded five years. Total costs of regeneration efforts were quantified and reported in only two studies. This lack of data on the expenses of different approaches to natural oak regeneration appears to be one of the most crucial knowledge deficits revealed in this literature review. Conclusion Natural regeneration of sessile oak may be achieved under a wide range of canopy openings, if competing vegetation and browsing is negligible, seedling density is high and tending to remove competing vegetation is carried out consistently. However, since the silvicultural regeneration success depends on the interactions among these factors, which have often not been adequately considered, we caution against general recommendations for silvicultural systems developed from case studies and call for new long-term studies with comprehensive experimental designs.
Sammendrag
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Sammendrag
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Sammendrag
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Forfattere
Anita SønstebySammendrag
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Forfattere
Anita SønstebySammendrag
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Forfattere
Mette Thomsen Erlend Indergård Pia Heltoft Thomsen Gerd Guren Anne-Berit Wold Hanne Larsen Belachew Asalf TadesseSammendrag
I prosjekt OPTIROT samarbeider 26 produsenter, to kjøleteknologiselskaper, en sensorutvikler, en biopesticidutvikler, to emballasjeprodusenter, fire regioner under NLR, Gartnerhallen og fem forskningsinstitutter (Nofima, Sintef, NMBU, Århus universitet og NIBIO) i gjennomføring av undersøkelser for å redusere svinn under lagring av gulrot, kålrot og sellerirot. Sammendrag av arbeidspakkene: i) Optimal gjødsling med bor og kalsium for bedre lagringskvalitet. Det er testet ut 6 ulike metoder /tidspunkter for tildeling av bor. Vi så liten effekt av de ulike metodene og tidspunktene for tildeling av bor til knollselleri (felter LI & ST) og kålrot (felter APP & INN). Symptomene bormangel og brune flekker ses inne i røtten og bedømmes ved deling av roten. I begge kulturer var det stor variasjon mellom felt. For knollselleri var det størst forekomst av brune flekker og lavest andel friske røtter i ST, som hadde lavest Ca/B-forhold i blader, lavest innhold av Zn i blader og røtter og lavest pH. I kålrot var det symptomer på bormangel i begge felt i 2017, sterkest i INN. For begge felt var symptomene sterkest i behandlingr uten tilførsel av B. Andel friske røtter var lavest i INN. Vi anbefaler flere undersøkelser for å konkludere ytterligere....
Sammendrag
One of the most important factors affecting photosynthesis and metabolism is light absorbance by leaves and penetration through the canopy. The aim of this study was to evaluate the influence of planting density and tree development stages on photosynthetic activity, photosynthetic pigments, and carbohydrates in apple (Malus domestica Borkh.) trees in a combined way. The apple tree, Auksis, was grafted on dwarfing rootstock P 22. Space between rows was 3 m, trees were planted in 2001 in four distances: 0.25 m, 0.50 m, 0.75 m, and 1.00 m. Measurements and leaf samples were taken in the end of May (leaves fully expanded BBCH 20–25), in the middle of July (beginning of apple maturity BBCH 73–75) and at the end of August (harvest time BBCH 87–88) according BBCH—growth stages. Photosynthetic rate was significantly the lowest in the spring and tended to rise until fruit ripening, when it increased up to 19.4% compared to spring. Significantly the highest chlorophyll b and carotene α and β contents were found at the BBCH 73–75. The lowest levels of fructose and sorbitol in leaves were found at BBCH 73–75. The amount of starch accumulated in the leaves increased three times in summer compared to spring. Reduced distance between trees to four times (from 1 m to 0.25 m) showed clear competitive stress, as the decrease of photosynthetic rate (up to 36.4–38.6%) and total starch (up to 37–53%) was observed. The photosynthetic behaviour of apple trees was significantly affected by the development stage during the particular season which is related with physiological changes of metabolites transport and their distribution during fruit ripening and leaf senescence.
Sammendrag
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