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.
2019
Authors
Erlend Indergård Mette Thomsen Pia Heltoft Thomsen Belachew Asalf Tadesse Berit Nordskog Kristina Norne Widell Tom Ståle Nordtvedt Torgeir Tajet Hanne LarsenAbstract
After harvesting, the Norwegian root vegetables are normally stored at refrigerated temperatures for 5 to 7 months. During this period, up to 30% of the products are lost. The goal is to reduce the diseases, the product loss and energy consumption, in addition to increase shelf-life and storage period. Twenty-eight commercial root vegetable cold-stores were instrumented to measure air temperature, relative humidity and product temperature. The study was done over two years. The cold-stores were located in four different regions of Norway. The three focus-products carrot, swede and celeriac were harvested from one field in each region in open wire nets. The nets were placed in the various cold-stores in the respective regions and put in the wooden bins together with the producer's own products. The quality and yield of the products were determined and correlated to the storage condition. The various storage condition negatively affects the respiration and quality of the root vegetables, storage-life, and influence on the cooling capacity of the refrigeration systems.
Authors
Hege Divon Lise Bøe Martha Tveit Sonja KlemsdalAbstract
Fusarium langsethiae is one of the common Fusarium species infecting small grain cereals in the Nordic region and the UK. It is usually described as a weak pathogen, and with a strong preference for oats, although no studies have yet addressed the explanations for this at the microscopic level. Using microscope techniques we have studied the early steps of colonization of oat and wheat grain by F. langsethiae particularly addressing the role of pollen in the infection process and the fungal ability to penetrate plant cell wall. The aim was to better understand its non-aggressive colonization picture and why oat is preferred over wheat as a host. Spray inoculated oat and wheat plants were scored for fungal progression at 3, 6, 10 and 14 days post inoculation (dpi) using light microscopy and scanning electron microscopy (SEM). Fungal hyphae entered the grain at the apex, or along the sides in the overlapping zone between palea wings and lemma, then spread basipetally and laterally, with a clear directional growth towards the caryopsis. Hyphal growth was clearly aided by the presence of pollen. On oat proliferating hyphae developed a variety of penetration structures on all internal surfaces. F. langsethiae infection on wheat progressed along the same routes, however slower and overall with less hyphal mass. Interestingly, hyphae closely associated to the wheat caryopsis seemed to undergo degradation, and profuse conidiation was observed at 14 dpi. Explanations for the differences in F. langsethiae colonization of oat versus wheat are suggested in light of the results.
Authors
Jan Magnusson Stephanie Eisner Shaochun Huang Cristian Lussana Giulia Mazzotti Richard Essery Tuomo Saloranta Stein BeldringAbstract
Climate models show that global warming will disproportionately influence high‐latitude regions and indicate drastic changes in, among others, seasonal snow cover. However, current continental and global simulations covering these regions are often run at coarse grid resolutions, potentially introducing large errors in computed fluxes and states. To quantify some of these errors, we have assessed the sensitivity of an energy‐balance snow model to changes in grid resolution using a multiparametrization framework for the spatial domain of mainland Norway. The framework has allowed us to systematically test how different parametrizations, describing a set of processes, influence the discrepancy, here termed the scale error, between the coarser (5 to 50‐km) and finest (1‐km) resolution. The simulations were set up such that liquid and solid precipitation was identical between the different resolutions, and differences between the simulations arise mainly during the ablation period. The analysis presented in this study focuses on evaluating the scale error for several variables relevant for hydrological and land surface modelling, such as snow water equivalent and turbulent heat exchanges. The analysis reveals that the choice of method for routing liquid water through the snowpack influences the scale error most for snow water equivalent, followed by the type of parametrizations used for computing turbulent heat fluxes and albedo. For turbulent heat exchanges, the scale error is mainly influenced by model assumptions related to atmospheric stability. Finally, regions with strong meteorological and topographic variability show larger scale errors than more homogenous regions.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Katharina Strobl Johannes Kollmann Leonardo H. TeixeiraAbstract
Ecological restoration has great potential for reversing anthropogenic degradation, as it aims at the simultaneous recovery of several ecosystem functions and services. However, it can be challenging to evaluate multiple restoration targets based on a high number of indicators, and this calls for a multifunctionality approach. Multifunctionality is an integrated measure of the relative supply of multiple ecosystem functions or services. As temporal aspects are of key importance for ecosystem recovery, we analyzed multifunctionality against time since restoration. We used rewetted peatlands in a mountainous region in Central Germany as a study case. Restored peatlands are expected to become multifunctional, while their recovery is rather slow. We investigated to what extent rewetted peatlands recover, and how time since restoration controls the simultaneous development of multiple ecosystem properties. We studied restored peatlands with respect to plant diversity, water table, peat decomposition, water holding capacity, and nutrient level using a chronosequence of 0–18 yr after restoration. We analyzed the development of individual properties and of a combined index. We further compared the recovery of restored sites at different ages to an intact reference peatland and to a theoretical optimum value, defined as the mean of the eleven most desirable values observed. Eleven out of 13 peatland properties and the combined index significantly evolved with time since restoration. Nevertheless, we could not observe a consistent trend of multiple properties if aiming at highest levels of functioning, whereas there was progress with time if low or intermediate functioning is targeted. Our results show that not all functions of restored peatlands can recover to the most desirable extent within 18 yr. However, the average functionality and some individual properties achieved levels comparable to the reference site, highlighting that improvement is possible. While the integrated assessment informs about the degree of ecosystem recovery, an additional analysis of individual properties helps understanding ecosystem‐specific dynamics, which are needed for making decisions on potential future management.
Authors
Richard Meadow Tor J. Johansen Gunda Thöming Annette Folkedal Schjøll Belén Cotes Christian NansenAbstract
No abstract has been registered
Authors
Arne HermansenAbstract
No abstract has been registered