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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2024

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Abstract

The effects of various cellulose treatments on the hydrophobic properties and sorption behavior with respect to liquid water uptake and water vapor sorption were examined within the study. Different hydrophobic agents based on silicon compounds were applied to improve the properties of cellulose-based sheets. The 1H,1H,2H,2H perfluorooctyltriethoxysilane treatment increased hydrophobicity significantly, while N-octyltriethoxysilane and inorganic sodium silicate solution treatments only slightly affected the properties. Silicone-cellulose interaction varied, influencing the fiber saturation and moisture content of the material. The swelling differences between untreated and treated cellulose and, consequently, the uncovering of new active sorption sites during a swelling process and the increase in the content of bound water were confirmed by the T2 relaxation times analysis. The GDW sorption model estimated maximum water content but lacked activation dynamics. The blocking phenomenon of active sorption sites together with silicone improved hydrophobicity had different mechanisms for applied agents. The 1H,1H,2H,2H perfluorooctyltriethoxysilane additionally cross-linked silane structure and restricted cellulose swelling.

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Abstract

Background Vegetated infiltration systems such as raingardens and bioswales are challenging for plant growth and survival due to fluctuating hydrological conditions and further subsequent stresses. Aim Here, we investigated the effect of fluctuation hydrology on growth and flowering and subsequent winter frost hardiness or spring salt tolerance for two common raingarden plant species, Filipendula ulmaria, and Calamagrostis ×acutiflora ‘Karl Foerster’, under controlled conditions. Methods During summer, plants were exposed to four hydrological regimes, each with a different combination of repeating dry and wet cycles. Then, after natural winter acclimation and storage, plants went through standardized freezing tests to determine LT50 and regrowth potential or were exposed to four levels of salt treatments (Control, 28 mM, 56 mM, and 84 mM NaCl) in the following spring. Results We found that fluctuating hydrology reduced the growth of Filipendula ulmaria, experiencing cycles of 72 hours of flooding and 264 hours of drained conditions, followed by a reduction of growth and flowering after salt exposure. Calamagrostis xacutiflora was less responsive to both fluctuating hydrology and salinity. Cycles with the longest dry conditions (Wet-dry cycles) showed the strongest negative effect on the performance of tested species. The hydrological regimes did not influence freezing tolerance in either species. Conclusion Moderate hydrological fluctuations did not cause damage to vegetation in vegetated infiltration systems, at least under shaded conditions. At the same time, drought tolerance is an important trait for species and cultivars in raingardens during hydrological fluctuations. Our prediction that hydrological conditions that negatively affected plant growth would reduce subsequent frost and salinity tolerance was only partially supported.

Abstract

Import of leeches for medical use and hobby keeping poses a low risk of negative effects on Norwegian biodiversity. The two species of leeches (Hirudo medicinalis and H. verbana) have in recent years become more commonly used in Western medicine for various procedures where maintaining good blood flow is important. Hirudo medicinalis is considered native to Norway and is found in scattered populations in southern Norway. There is uncertainty about the genetic impact on these populations if imported leeches were to be released into the wild. Hirudo verbana is not registered in Norway but may have been imported as H. medicinalis in the past. Both species are listed under Appendix I, List B of the Norwegian CITES regulations. Methods VKM reviewed scientific literature to uncover potential negative effects in light of the leeches’ ecology under Norwegian conditions. VKM also investigated how the trade in live leeches is conducted, where they originate from, and outlined possible risk-reducing measures. VKM assessed four factors of potential relevance for negative impacts on biodiversity and conducted risk assessments for each: Hybridisation or other negative genetic impacts on local populations Competition with other leech species Parasitism or predation on amphibian populations Transmission of diseases Additionally, VKM assessed the extent of such imports and the likelihood of imported leeches ending up in Norwegian nature. Results VKM concluded that it is moderately likely that H. medicinalis will genetically affect Norwegian populations, but this will have minimal negative effects. Hybridisation between H. verbana and H. medicinalis is considered unlikely and would have little effect if it occurs. ”The leeches already present in Norway mainly originate from leeches imported from Europe in the 1800s. The introduction of new genes from the same areas now will therefore have minimal impact. The risk is therefore low,” says Lawrence Kirkendall, the scientific leader of the work. For parasitism or predation, amphibians are the main species that could theoretically be negatively affected by the leeches. VKM concludes that such negative effects are very unlikely and would have little or minimal impact. This implies low risk. Regarding competition and disease transmission, VKM assesses that these factors have little or minimal effect on biodiversity and are very unlikely. "We assess that the effects on biodiversity in Norway, if imported leeches were to end up in an environment where they thrive, are very small. At the same time, it is very unlikely that leeches used for medical procedures will end up in nature. The overall assessment is therefore that both species are associated with low risk of negative impact on biodiversity," says Kirkendall. The risk assessment is approved by the VKM Panel for Biodiversity.