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
Sammendrag
Horse owners may lack knowledge about natural thermoregulation mechanisms in horses. Horses are managed intensively; usually stabled at night and turned out during the day. Some are clipped and many wear a blanket, practices which reduce the horse's ability to regulate heat dissipation. The aim of this study was to investigate the relationship between hair coat characteristics, body condition and infrared surface temperatures from different body parts of horses. Under standard conditions, the body surface temperature of 21 adult horses were investigated using infrared thermography. From several readings on the same body part, a mean temperature was calculated for each body part per horse. Detailed information on horse breed, age, management and body condition was collected. Hair coat samples were also taken for analyses. A mixed statistical model was applied. Warmblood horse types (WB) had lower hair coat sample weights and shorter hair length than coldblood horse types (CB). The highest radiant surface temperatures were found at the chest 22.5 ± 0.9 °C and shoulders 20.4 ± 1.1 °C and WB horses had significantly higher surface temperatures than CB horses on the rump (P < 0.05). Horses with a higher hair coat sample weight had a lower surface temperature (P < 0.001) and hind hooves with iron shoes had a significant lower surface temperature than unshod hind hooves (P = 0.03). In conclusion, individual assessment of radiant surface temperature using infrared thermography might be a promising tool to gather data on heat loss from the horses' body. Such data may be important for management advice, as the results showed individual differences in hair coat characteristics and body condition in horses of similar breeds.
Sammendrag
Apples are an important source of bioactive compounds, especially mineral nutrients. Minerals (both macro- and micro-elements) are responsible for the functioning of the human body, and involved in the metabolism and production of carbohydrates, lipids, proteins, vitamins and enzymes. The objective of this study was to determine and compare the content of some minerals (K, P, Ca, Mg and Fe) of two different apple cultivars (‘Red Aroma Orelind’ and ‘Discovery’), both in peel and pulp, grown in organic and integrated production systems in western Norway in 2015. Samples of fruits were prepared by microwave digestion using an Ethos 1 microwave system. All analyses were performed in triplicate on a Thermo Scientific iCAP 6500 Duo ICP. The results showed that potassium was found in the largest quantity in both apple cultivars and in both management systems and average concentration was 944.3 µg g-1 of fresh weight (FW). Calcium was in second place with average of 180.6 µg g-1 FW. Both apple cultivars had largest amounts of both K and P (in peel and flesh) from organic production compared to fruits coming from the integrated production system. The cultivar ‘Red Aroma Orelind’ had a significantly higher level of Fe in organic fruits compared to integrated. The present study showed that the highest values of K/Ca, (K+Mg)/Ca and Mg/Ca were obtained from the cultivar ‘Discovery’ under organic production (both in peel and flesh). Regarding significantly higher concentrations of P, K, Mg, Fe and balanced mineral ratios in organic apples, it can be concluded that those fruits have higher quality, and are at lower risk of bitter pit when stored.
Forfattere
Anna Katharina Pilsbacher Bente Lindgård Rigmor Reiersen Victoria Gonzalez Kari Anne BråthenSammendrag
1. Altered species composition caused by environmental and climatic change can affect the transfer of plant residues among communities. Whereas transferred residues are typically considered a resource in recipient systems, residues of allelopathic species may instead cause interference. 2. Evergreen dwarf shrubs, specifically the allelopathic species Empetrum nigrum are increasing in abundance in response to a warming climate. Empetrum has small, evergreen leaves that can be transferred to other communities when withered and lost from the plant. 3. We hypothesize that Empetrum can have allelopathic effects in the recipient communities of the withered leaves. We call this allochthonous allelopathy as opposed to autochthonous allelopathy, which is well documented in communities where the plant grows. 4. We measured influx of allochthonous Empetrum leaves onto snow-covered snowbeds, where they are easily identified within the debris. Next, we compared the bioactivity of allochthonous withered leaves with that of green Empetrum leaves. Finally, we conducted an experiment testing the germination and seedling growth of 10 tundra species in snowbed soil supplemented with no (control) and three densities of allochthonous Empetrum leaves. 5. We found Empetrum leaves to be common on the snow cover of snowbeds. We found Empetrum leaves collected on snowbeds to be as bioactive as green leaves. Finally, we found forb species to have reduced germination and all 10 species to have delayed seedling development when growing in snowbed soil supplemented with withered Empetrum leaves. Seedlings under the control treatment were 2.3 times longer and had 3.2 times more leaves in comparison to seedlings grown under the strongest allochthonous leaf treatment. 6. Results from our study imply that Empetrum is allelopathic in recipient systems of its allochthonous leaves. The abundant nature of Empetrum in the tundra suggests that allochthonous allelopathy is a common phenomenon, causing biotic stress in snowbeds and potentially other parts of the tundra. Exemplifying the ability of a plant to interfere in neighbouring communities, our study demonstrates a plant trait that may provide insight to other study systems.
Sammendrag
This paper analyses two strategies to reduce the use of pesticides in grain production. We study Norwegian farmers’ willingness to voluntarily forego income by reducing pesticide use as well as their responses to a doubling of the pesticide price (through increased pesticide taxes). We use mixed methods including an experiment, a survey and focus group discussions. The experiment shows that most farmers are willing to sacrifice some income to reduce environmental risks by using less pesticide. According to the survey, they are, at the same time, relatively insensitive to a 100% price increase on herbicides and fungicides. While the response to the price increase probably would have been stronger if differentiated between chemicals, our research indicates potential benefits from supporting voluntary action. Value orientations and agronomic conditions influence the stated responses in both circumstances. Respondents emphasizing environmental values are more willing to voluntarily reduce pesticide use and show a greater response to the economic incentive than farmers emphasizing economic outcome and issues such as clean fields. A hypothesized willingness to reduce pesticide use voluntarily to strengthen the reputation of the sector was, however, rejected. Farmers appear to have few alternatives to pesticides, but increased knowledge about the alternatives that do exist, seems able to promote some change. Our findings suggest that the extension service should put greater emphasis on these options, even if they may have negative effects on income.
Forfattere
Liz Veerman Karsten Kalbitz Per Gundersen O. Janne Kjønaas Filip Moldan Patrick Schleppi Emiel E. van Loon Jorien Schoorl Wim Wessel Albert TietemaSammendrag
Increased anthropogenic nitrogen (N) inputs can alter the N cycle and affect forest ecosystem functions. The impact of increased N deposition depends among others on the ultimate fate of N in plant and soil N pools. Short-term studies (3-18 months) have shown that the organic soil layer was the dominant sink for N. However, longer time scales are needed to investigate the long-term fate of N. Therefore, the soils of four experimental forest sites across Europe were re-sampled similar to 2 decades after labelling with(15)N. The sites covered a wide range of ambient N deposition varying from 13 to 58 kg N ha(-1)year(-1). To investigate the effects of different N loads on(15)N recovery, ambient N levels were experimentally increased or decreased. We hypothesized that: (1) the mineral soil would become the dominant(15)N sink after 2 decades, (2) long-term increased N deposition would lead to lower(15)N recovery levels in the soil and (3) variables related to C dynamics would have the largest impact on(15)N recovery in the soil. The results show that large amounts of the added(15)N remain in the soil after 2 decades and at 2 out of 4 sites the(15)N recovery levels are higher in the mineral soil than in the organic soil. The results show no clear responses of the isotopic signature to the changes in N deposition. Several environmental drivers are identified as controlling factors for long-term(15)N recovery. Most drivers that significantly contribute to(15)N recovery are strongly related to the soil organic matter (SOM) content. These findings are consistent with the idea that much of the added(15)N is immobilized in the SOM. In the organic soil layer, we identify C stock, thickness of the organic layer, N-status and mean annual temperature of the forest sites as most important controlling factors. In the mineral soil we identify C stock, C content, pH, moisture content, bulk density, temperature, precipitation and forest stand age as most important controlling factors. Overall, our results show that these temperate forests are capable of retaining long-term increased N inputs preferably when SOM availability is high and SOM turnover and N availability are low.
Forfattere
Eli Knispel Rueness Maria Gulbrandsen Asmyhr Hugo de Boer Katrine Eldegard Lars Robert Hole Kjetil Hindar Johanna Järnegren Kyrre Linné Kausrud Lawrence Richard Kirkendall Inger Elisabeth Måren Erlend Birkeland Nilsen Anders Nielsen Eva Bonsak Thorstad Gaute VelleSammendrag
Key words: Ursus maritimus, CITES, polar bear, Non-Detriment Finding, Norwegian Scientific Committee for Food and Environment, Norwegian Environment Agency, VKM Background: Canada is the only nation in the world that allows commercial export of polar bear products harvested from its own wild populations. Norway is among the destinations for exported material. Polar bears are listed on CITES appendix II and on list B of the Norwegian CITES Regulation. Import of harvested polar bears to Norway requires both export permits from the Canadian CITES authorities and import permits from the Norwegian Environment Agency. Consequently, a Non-Detriment Finding (NDF) is mandated and was commissioned by the Norwegian Environment Agency (Norwegian Management Authority for CITES) to the Norwegian Scientific Committee for Food and Environment (VKM) (Norway’s CITES Scientific Authority). The NDF is a scientific risk assessment evaluating whether or not international trade can be detrimental to the survival of polar bears. The risk assessment may also be used by the Norwegian Environment Agency to assess whether the polar bears should be placed on Norwegian CITES list A. Currently, the IUCN/SSC Polar Bear Specialist Group (PBSG) recognizes 19 subpopulations of polar bears in the circumpolar Arctic, of which 13 reside wholly (9) or partly (4) in Canada. Together, these 13 populations account for about two thirds of the world’s total polar bear population. This risk assessment considers the populations that are within the hunting areas. Methods: VKM has reviewed current knowledge about polar bear biological characteristics, population status and trends in subpopulations. Scenarios for the future development of the Arctic environment, to which the species is inextricably adapted, are presented. Habitat loss due to declining sea ice is widely recognized as the main threat to polar bears, and this, as well as other obstacles to the species survival, has been evaluated. The various legislations, regulations and monitoring regimes of the range countries are briefly summarised. Moreover, international trade in polar bear products has been analysed. VKM has further undertaken an assessment of data quality and uncertainties. In order to gain access to the most recent information on polar bear biology and management, four scientists from the PBSG were interviewed and the transcripts of the interviews (with consent from the hearing experts) are attached to this report. Results: The best scientific knowledge available for polar bears in Canada suggests that four subpopulations are in decline, two are stable, and one is increasing, while the population trends for the remaining subpopulations are unknown. Noteworthy, all the estimates of population size are highly uncertain. Survey methods also changed between the 2008 and 2018 population estimates used for quota setting. Moreover, data are in most areas collected too infrequently to detect rapid changes in population size. Particularly, under changing environmental conditions. The prognosis for the Arctic marine environment points towards continuing habitat loss and inevitably further decline for the polar bear population. Analyses of data from the CITES trade database reveal a dynamic international market for polar bear products with significant changes in destination countries and the purpose for transactions. The United States was the main importer of polar bear products, mainly hunting trophies, until listing the polar bear as a threatened species in 2008. In more recent years, China has become the major importer, with hides being the preferred product. Simultaneously with these changes, there has been a significant increase in the price of polar bear hides. Conclusion: Several polar bear subpopulations are in decline. Predictions of continuing habitat loss points to further decline. While not the main threat to polar bear survival, international trade .......
Sammendrag
BACKGROUND Low growth temperatures and the special light qualities of midnight sun in northern Scandinavia, have both been shown to improve eating quality of swede root bulbs. To study the combined effect of these factors on root development and sensory‐related compounds, plants were grown in phytotron under different 24 h supplemental light‐emitting diode (LED) light colours, at constant 15 °C, or reduced end‐of‐season temperature at 9 °C. RESULTS Far‐red LED (740 nm) light induced longer leaves and produced more roundly shaped bulbs, than the other light quality treatments. At constant 15 °C, supplemental light of far‐red LED also produced a stronger purple crown skin colour than the other LED treatments. This difference between light quality treatments disappeared at 9 °C, as all bulb crowns developed a purple colour. There were no significant effects of LED‐supplements on sugar concentrations, while the reduced temperature on average did increase concentrations of d‐fructose and d‐glucose. Total glucosinolate concentrations were not different among treatments, although the most abundant glucosinolate, progoitrin, on average was present in highest concentration under LEDs containing far‐red light, and in lower concentration at 9 °C compared to 15 °C. CONCLUSION The light quality of 24 h photoperiods in combination with temperature appears primarily important for growth and morphological traits in swede root bulbs. Influence of light quality and low temperature on appearance and sensory‐related compounds may be utilized in marketing of root vegetables with special quality related to growth conditions of high latitude origin. © 2020 Society of Chemical Industry
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.
Forfattere
Kamilla Skaalsveen Julie Ingram Julie UrquhartSammendrag
This paper draws on network science and uses a Social Network Analysis to improve our understanding of how the implementation of no-till in England is influenced by farmers' social networks. No-till is a low disturbance farming practice with potential to benefit soil health, the aquatic environment and farm economy, but is currently only implemented at a small scale in Europe. Interpersonal networks are important for farmers and influence farmer learning and decision-making and farmers often view each other as their main source of information. In this study, the social networks of 16 no-till farmers in England were mapped and semi-structured interviews carried out to assess the link between farmer network characteristics and the implementation of no-till in England. We also aimed to improve our understanding of the nature and extent of knowledge exchanged within farmer networks and their spatial and temporal dynamics. Our findings suggest that intermediary farmers had an important role in increasing the information flow and knowledge exchange between the different clusters of the no-till farmer network. These intermediaries were also the biggest influencers as they were often no-till farmers with a high level of experiential knowledge and viewed as important sources of information by other farmers. No-till farmer networks were geographically distributed as the farmers preferred to discuss farming practices with similar minded no-till farmers rather than local conventional farmers who did not understand what they were trying to achieve. Therefore, online communication platforms like social media were important for communication. We question the role of formal extension services in supporting farmers with innovative practices like no-till and suggest that advisors should strive to improve their understanding of these well-developed information networks to enable a more streamlined and efficient information diffusion.
Sammendrag
There is an increasing interest in plastics, both as a resource and as a pollutant. In Europe, 25.8 million tons of plastic waste are generated each year, and their effects on climate, economy, human and environmental health are major challenges that society needs to address. Although a lot of emphasis is placed on recycling, the use of recycled plastics is still low in the EU. In this context, climate change and environmental concerns have boosted the development of various types of biodegradable plastics. The use of biodegradable plastics spans from disposable containers for food/drink, serviceware and wipes, via waste bags for organic waste collected for biogas production, to agricultural films used to cover soil during vegetable production. However, biodegradable plastics are rarely degraded so quickly and completely that the products disappear in nature, and the label may encourage people think otherwise, enhancing littering. The aim of our study was to describe the fate of biodegradable materials and products during waste treatment, and more specifically during composting. How long does it take these materials to degrade? What are the conditions for degradation, and ultimately, for obtaining plastic-free compost products? To answer these questions, we selected relevant materials, including compostable serviceware, biodegradable plastic bags used for organic waste collection, and biodegradable agricultural mulch films. Composting experiments were performed both at lab-scale (1.5 L containers with externally applied heating) and larger scale (in 140 L insulated compost tumblers, with natural heating from the composting processes, continuously monitored). The endpoints studied were recovery, mass loss, changes in morphology and composition, and microbial analysis of the various composts. In addition, we assessed the applicability of chemical digestion methods used for sample pretreatment of environmental samples containing conventional plastics to biodegradable plastics. Biodegradable plastics is an umbrella term covering materials with diverse polymeric compositions and thus material properties. This was well demonstrated by our selected materials, which displayed distinct degradation behaviors under similar controlled conditions. The time-course of degradation during composting will be presented for all selected materials, together with the main parameters influencing their degradation rates. In addition, some methodological challenges in this research field will be discussed. Finally, experience from a municipal composting facility receiving biodegradable plastic waste will also be presented to put our laboratory-based results into perspective.