Hopp til hovedinnholdet

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

Til dokument

Sammendrag

Understanding the factors that determine species’ resistance to environmental change is of utmost importance for biodiversity conservation. Here we investigated how the abundances of marshland species are determined by niche properties and functional traits. We re-surveyed 150 vegetation plots that were first surveyed in 1973 in order to explore species abundance changes over time. We found that the mean water level in the habitats of most studied species decreased significantly from 1973 to 2012. Nine of 17 target species were identified as abundance decreasing species and the other eight as abundance increasing species. The comparisons of seven plant characteristics (niche position water level, plant height, and five leaf traits) showed that the decreasing species had a significantly higher value of optimum water level and marginally significantly lower leaf N contents and specific leaf area (SLA) than those in increasing species. The stepwise regression analysis showed that optimum water level and leaf N were the best predictors of abundance changes of marsh plant species, as well as that the effect of optimum water level was stronger than that of leaf N. Our findings demonstrated that niche properties may be important for forecasting changes in wetland plant communities over time.

Til dokument

Sammendrag

Biological control of pests is a growing market in the world. It is expected that the use entomopathogenic fungi to control pests will take an important share of this market. Most fungal products in the world are based on aerial conidia produced by solid fermentation using cereal grains. An alternative for aerial conidia is the use of blastospores, yeast-like hydrophilic cells that can be produced in large amounts by liquid fermentation in a short time (<4 days), in a small space and with low hand labor compared to the solid fermentation method. Therefore, the main objectives of the present studies were first to optimize a liquid culture medium for low cost production of Metarhizium blastopores; second: to assess the bioactivity of air-dried blastospores against the cattle-tick Rhipicephalus microplus and the corn-leafhopper Dalbulus maidis; third: to develop an air-dried and spray-dried Metarhizium blastospore formulation with bioactivity against the corn-leafhopper D. maidis; fourth: to improve the shelf-life of the best air-dried and spray-dried formulations stored in refrigerated (± 4°C) and in ambient conditions (28°C) using oxygen and moistures absorbrs or vacuum and fifth: to use comparative genome-wide transcriptome analyses to determine changes in gene expression between the filamentous and blastospore growth phases in vitro to characterize physiological changes and metabolic signatures associated with M. anisopliae and M. rileyi dimorphism. We showed that blastospore production of Metarhizium is isolate- and species-dependent.Glucose-enriched cultures inoculated with pre-cultures improved yields reaching optimal growth for Metarhizium robertsii ESALQ1426 (5.9 × 108 blastospores/mL) within 2 d. We argue that both osmotic pressure, induced by high glucose titers, and isolate selection are critical to produce high yields of blastospores. [...]

Til dokument

Sammendrag

Probiotics confer a health benefit on the host and could be used as a good alternative to antibiotics. Probiotics are strain‐specific when exerting their function, so it is necessary to identify them to strain level. In recent years, intra‐species molecular typing and identification methods have developed rapidly, which commonly are used for typing the main pathogenic bacteria and rare for studies on probiotic typing, whilst it is imperative. This article describes molecular typing methods including AFLP, RAPD, PFGE, ribotyping, MLST, rep‐PCR and whole‐genome sequencing to identity some aquatic probiotics approved by the Ministry of Agriculture of China, which are Bifidobacterium, Enterococcus, Lactobacillus, Pediococcus, Aspergillus, Bacillus, Rhodopseudomonas palustris and Streptococcus thermophilus. In addition, the principles, applications, advantages and disadvantages of these typing methods are also discussed.

Til dokument

Sammendrag

Afforestation of marginal cultivated land is an internationally approved climate mitigation strategy, however, with uncertain implications for soil organic carbon (SOC) storage. We examined the effect of forest planting by measuring SOC at two adjacent sites: one with a Norway spruce forest planted in 1968 and one actively grazed pasture. Both sites had similar land-use history before forest planting, and they were as similar as possible in all other edaphic factors. There were no significant differences in SOC stocks down to 30 cm mineral soil, 7.15 and 8.51 kg C m−2 in the forest plantation and pasture respectively. Only a minimal build-up of an O horizon, less than 2 cm, was observed in the plantation. The SOC stocks of the plantation and pasture were not significantly different from that of a nearby old forest, 7.17 kg C m−2. When comparing these three land-uses we found that there were significant differences in the upper 10 cm of the soil with regard to other soil properties. Nitrogen (N) stock and pH were significantly lower in the old forest compared to the plantation, which again was significantly lower than that of the pasture. The opposite was the case for the C/N ratio. We conclude that there were no significant differences in SOC stocks in the upper 30 cm 50 years after afforestation with Norway spruce, but that there is still a legacy from the former cultivation that may influence both productivity and organic matter dynamics.