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.
2022
Forfattere
Lu Feng Mihaela Tanase Opedal Francesca Di Bartolomeo Sidsel Markussen Aniko Varnai Svein Jarle HornSammendrag
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Sammendrag
I Oslo-området er det oppdaget mye skader av Phytophthora på trær. Phytophthora er en slekt med fremmede, invaderende planteskadegjørere som angriper og ødelegger røttene til tre- og urteaktige planter. Phytophthora spres ofte via handel med infiserte planter der de følger med plantene som blindpassasjerer i rotklumpen og mange funn er oppdaga på importerte grøntanleggsplanter til Norge. Derfor ble 60 jordprøver fra nyplantede bytrær tatt ut og analysert for Phytophthora i september 2022. Totalt ble 11 Phytophthora-arter påvist i 17 av de 60 prøvene: Phytophthora bilorbang, P. cactorum, P. cambivora, P. gallica, P. gonapodyides, P. hedraiandra (el. P. cactorum - kunne ikke separeres ved standard DNA-analyse), P. megasperma, P. × multiformis, P. plurivora, P. syringae og P. ukrainensis. I tillegg var det tre flisprøver fra svartorer med blødende stammesår og glisne kroner som gav positivt utslag på hurtigtest (LFD) for Phytophthora. Av de påviste Phytophthora-artene er det flere kjente skadegjørere som dreper trær i Norge, f.eks. P. cactorum, P. cambivora og P. plurivora. For andre arter mangler vi kunnskap om deres innvirkning på norsk natur og deres aggressivitet på norske planter. Phytophthora × multiformis og P. ukrainensis har aldri tidligere blitt funnet i Norge. Ingen av Phytophthora-artene som ble påvist har karantenestatus, men flertallet regnes som såkalte kvalitetsskadegjørere. Der Phytophthora-artene ble påvist er det stor sannsynlighet for at massene (jord og røtter) knyttet til trærne er smittet. Det innebærer restriksjoner ved flytting av masser ved disse lokalitetene. De sjuke/døende trærne som fjernes og erstattes, må håndteres på riktig måte for å unngå ytterligere spredning av Phytophthora. I rapporten diskuteres aktuelle tiltak ut fra den samlede kunnskapen som i dag er tilgjengelig nasjonalt og internasjonalt.
Sammendrag
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Forfattere
Milica Fotirić Akšić Dragana Dabić Zagorac Uroš Gašić Tomislav Tosti Maja Natić Mekjell MelandSammendrag
The aim of this study was to compare total phenolic content (TPC), radical-scavenging activity (RSA), total anthocyanin content (TAC), sugar and polyphenolic profiles of two apple cultivars (‘Discovery’ and ‘Red Aroma Orelind’) from organic and integrated production systems in climatic conditions of Western Norway. Sixteen sugars and four sugar alcohols and 19 polyphenols were found in the peel, but less polyphenols were detected in the pulp. The peel of both apples and in both production systems had significantly higher TPC and RSA than the pulp. The peel from integrated apples had higher TPC than the peel from organic apples, while organic apples had higher TAC than the integrated. Sucrose and glucose levels were higher in organic apples; fructose was cultivar dependent while minor sugars were higher in integrated fruits. The most abundant polyphenolic compound in the peel of the tested cultivars was quercetin 3-O-galactoside, while chlorogenic acid was most abundant in the pulp. Regarding polyphenols, phloretin, phloridzin, protocatechuic acid, baicalein and naringenin were higher in organic apple, while quercetin 3-O-galactoside, kaempferol 3-O-glucoside, chlorogenic acid and syringic acid was higher in integrated fruits. In conclusion, organic ‘Discovery’ and integrated ‘Red Aroma Orelind’ had higher bioavailability of health related compounds from the peel and the pulp.
Forfattere
Vindhya Basnayaka Jayanga T. Samarasinghe Miyuru Gunathilake Nitin Muttil Dileepa C. Hettiarachchi Amila Abeynayaka Upaka RathnayakeSammendrag
River meandering and anabranching have become major problems in many large rivers that carry significant amounts of sediment worldwide. The morphodynamics of these rivers are complex due to the temporal variation of flows. However, the availability of remote sensing data and geographic information systems (GISs) provides the opportunity to analyze the morphological changes in river systems both quantitatively and qualitatively. The present study investigated the temporal changes in the river morphology of the Deduru Oya (river) in Sri Lanka, which is a meandering river. The study covered a period of 32 years (1989 to 2021), using Landsat satellite data and the QGIS platform. Cloud-free Landsat 5 and Landsat 8 satellite images were extracted and processed to extract the river mask. The centerline of the river was generated using the extracted river mask, with the support of semi-automated digitizing software (WebPlotDigitizer). Freely available QGIS was used to investigate the temporal variation of river migration. The results of the study demonstrated that, over the past three decades, both the bend curvatures and the river migration rates of the meandering bends have generally increased with time. In addition, it was found that a higher number of meandering bends could be observed in the lower (most downstream) and the middle parts of the selected river segment. The current analysis indicates that the Deduru Oya has undergone considerable changes in its curvature and migration rates.
Forfattere
Miyuru GunathilakeSammendrag
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Forfattere
Yong Q. Tian Qian Yu Hunter J. Carrick Brian L. Becker Remegio Confesor Mark Francek Olivia C. AndersonSammendrag
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Sammendrag
Understanding the mechanisms of ecological community dynamics and how they could be affected by environmental changes is important. Population dynamic models have well known ecological parameters that describe key characteristics of species such as the effect of environmental noise and demographic variance on the dynamics, the long-term growth rate, and strength of density regulation. These parameters are also central for detecting and understanding changes in communities of species; however, incorporating such vital parameters into models of community dynamics is challenging. In this paper, we demonstrate how generalized linear mixed models specified as intercept-only models with different random effects can be used to fit dynamic species abundance distributions. Each random effect has an ecologically meaningful interpretation either describing general and species-specific responses to environmental stochasticity in time or space, or variation in growth rate and carrying capacity among species. We use simulations to show that the accuracy of the estimation depends on the strength of density regulation in discrete population dynamics. The estimation of different covariance and population dynamic parameters, with corresponding statistical uncertainties, is demonstrated for case studies of fish and bat communities. We find that species heterogeneity is the main factor of spatial and temporal community similarity for both case studies.
Sammendrag
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Redaktører
Randi HesjedalSammendrag
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