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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.

2023

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Abstract

Macroalgae, or seaweeds, have potential for use as feed ingredients and are currently unexploited despite their content of vitamins, minerals, and protein. Brown species can accumulate iodine from seawater and there are strict limits set by the European Food Safety Authority and the FDA regarding iodine content in animal feeds. Iodine can cause health problems for consumers if over or under-consumed and its presence in end food products is strictly regulated. The aim of the present experiment was to gain knowledge on intake, distribution, and excretion of iodine in sheep supplemented with Laminaria hyperborea by-product known to contain iodine. Twelve Norwegian White Sheep male lambs, four months of age, were blocked according to initial live weight (average 37.8 kg) and randomly allocated to two diet groups. Animals were fed gras silage and concentrate, without (CTR) and including the alga by-product at a 6% inclusion rate (HYP). The iodine concentrations were 4.1 and 476 mg/kg dry matter in the CTR and HYP concentrate, respectively. After 26 days of adaptation in a barn, animals were placed in metabolism crates for three consecutive days (Period 1) with collection of rumen fluid (via esophagus), grass silage, feces, urine, and blood for iodine content. After 5 weeks in the barn, animals returned to the metabolism crates for a subsequent three consecutive day sampling and iodine analyzes (Period 2). Data were analyzed via ANOVA using a repeated measure mixed model procedure. Dry matter intake (P = 0.001) and live weight (P = 0.001) increased from Period 1 to Period 2. Lambs fed CTR had higher daily growth rate than those fed HYP (P = 0.001). Iodine intake and excretion in feces and urine increased from Period 1 to Period 2 (P < 0.001, P = 0.010, P = 0.007, respectively). Iodine excreted in feces was 37% and 67% for lambs in fed the CTR and HYP diets, respectively. None of the animals showed signs of iodine poisoning during ten the experiment. We found that most of the iodine excreted from lambs fed the HYP diet was in feces.

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Abstract

Multi-scale evidence of rapid, climate-induced soil structural changes occurring at yearly to decadal timescales is mounting. As a result, it has become increasingly important to identify the properties and mechanisms controlling the development and maintenance of soil structure and associated macroporosity. This is especially relevant since macroporosity has disproportionate effects on saturated hydraulic conductivity ( ) which strongly influences water storage and flux, thus, affecting the water cycle. In this study, we use decision trees and piecewise linear regression to assess the influence of soil and climate properties on effective porosity (EP; a proxy of macroporosity) in both surface and subsurface horizons under varying land-use and management practices. Data from 1,491 pedons (3,679 horizons) spanning five ecoregions representing bioclimate (e.g., potential vegetation) across the conterminous US demonstrate that, at a continental scale, EP in surface (A) and subsurface (B) horizons is strongly dependent on the complexed fraction of the total mass of soil organic carbon (SOC) and clay; a combined fraction that we refer to as complexed organic carbon and clay (COCC). EP showed a slight positive response to COCC in A horizons but increased steeply with increasing COCC in B horizons. This is because the smaller values of COCC in B horizons reflect a larger pool of clay that has a greater potential to accommodate and complex additions of SOC promoting stronger organo-mineral bonds and the concomitant development and maintenance of soil structure in these horizons. In contrast, larger values of COCC in A horizons reflect conditions where all or most of the clay fraction is effectively complexed with SOC resulting in a larger pool of non-complexed soil organic matter with varying contrasting effects on macroporosity that ultimately mute the response of EP to increases in COCC. In surface horizons, indirect factors such as mean annual precipitation and land use were important predictors of EP, whereas COCC was more influential in controlling EP within the subsoil. The EP-COCC relationship also holds within ecoregions but its effect is mitigated by soil and climate interactions suggesting that the effect of climate on this relationship is indirect and complex. Plowed surface horizons and horizons underlying plowed layers showed greater homogenization (due to disturbance effects reducing heterogeneity in the soil) as well as a reduction in the magnitude and rate of change of EP as a function of COCC compared to undisturbed horizons. Our findings suggest that the complexed fraction of clay and SOC is important for controlling macroporosity and at ecoregion scales and that the EP-COCC relationship may be an important framework for understanding and predicting future land use- and climate-induced changes in soil hydraulic properties.

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Abstract

Grass pollen is a leading cause of allergy in many countries, particularly Europe. Although many elements of grass pollen production and dispersal are quite well researched, gaps still remain around the grass species that are predominant in the air and which of those are most likely to trigger allergy. In this comprehensive review we isolate the species aspect in grass pollen allergy by exploring the interdisciplinary interdependencies between plant ecology, public health, aerobiology, reproductive phenology and molecular ecology. We further identify current research gaps and provide open ended questions and recommendations for future research in an effort to focus the research community to develop novel strategies to combat grass pollen allergy. We emphasise the role of separating temperate and subtropical grasses, identified through divergence in evolutionary history, climate adaptations and flowering times. However, allergen cross-reactivity and the degree of IgE connectivity in sufferers between the two groups remains an area of active research. The importance of future research to identify allergen homology through biomolecular similarity and the connection to species taxonomy and practical implications of this to allergenicity is further emphasised. We also discuss the relevance of eDNA and molecular ecological techniques (DNA metabarcoding, qPCR and ELISA) as important tools in quantifying the connection between the biosphere with the atmosphere. By gaining more understanding of the connection between species-specific atmospheric eDNA and flowering phenology we will further elucidate the importance of species in releasing grass pollen and allergens to the atmosphere and their individual role in grass pollen allergy.

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Abstract

Aim Current global warming is driving changes in biological assemblages by increasing the number of thermophilic species while reducing the number of cold-adapted species, leading to thermophilization of these assemblages. However, there is increasing evidence that thermophilization might not keep pace with global warming, resulting in thermal lags. Here, we quantify the magnitude of thermal lags of plant assemblages in Norway during the last century and assess how their spatio-temporal variation is related to variables associated with temperature-change velocity, topographic heterogeneity, and habitat type. Location Norway. Time period 1905–2007. Major taxa studied Vascular plants. Methods We inferred floristic temperature from 16,351 plant assemblages and calculated the floristic temperature anomaly (difference between floristic temperature and baseline temperature) and thermal lag index (difference between reconstructed floristic temperature and observed climatic temperature) from 1905 until 2007. Using generalized least squares models, we analysed how the variation in observed lags since 1980 is related to temperature-change velocity (measured as magnitude, rate of temperature change, and distance to past analogous thermal conditions), topographic heterogeneity, and habitat type (forest versus non-forest), after accounting for the baseline temperature. Results The floristic temperature anomaly increases overall during the study period. However, thermophilization falls behind temperature change, causing a constantly increasing lag for the same period. The thermal lag index increases most strongly in the period after 1980, when it is best explained by variables related to temperature-change velocity. We also find a higher lag in non-forested areas, while no relationship is detected between the degree of thermal lag and fine-scale topographic heterogeneity. Main conclusions The thermal lag of plant assemblages has increased as global warming outpaces thermophilization responses. The current lag is associated with different dimensions of temperature-change velocity at a broad landscape scale, suggesting specifically that limited migration is an important contributor to the observed lags.

Abstract

This report provides an overview of resources for feed production from Norwegian bioresources. We look at present use of agricultural land, outfield pasture, forestry production and processing and present harvesting of bioresources from the ocean, as well as cultivation of marine organisms. We also look alternative uses of resources to produce feed.