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.
2022
Authors
Ingunn Øvsthus Mats Carlehög Guillaume Antalick Mitja Martelanc Tatjana Radovanovic Vukajlovic Lorena Butinar Melita, Sternad Lemut Branka, Mozetic VodopivecAbstract
No abstract has been registered
Authors
Johannes Schumacher Håvard Toft Larsen Paul McLean Marius Hauglin Rasmus Astrup Johannes BreidenbachAbstract
The number of people affected by snow avalanches during recreational activities has increased over the recent years. An instrument to reduce these numbers are improved terrain classification systems. One such system is the Avalanche Terrain Exposure Scale (ATES). Forests can provide some protection from avalanches, and information on forest attributes can be incorporated into avalanche hazard models such as the automated ATES model (AutoATES). The objectives of this study were to (i) map forest stem density and canopy-cover based on National Forest Inventory and remote sensing data and, (ii) use these forest attributes as input to the AutoATES model. We predicted stem density and directly calculated canopy-cover in a 20 Mha study area in Norway. The forest attributes were mapped for 16 m × 16 m pixels, which were used as input for the AutoATES model. The uncertainties of the stem number and canopy-cover maps were 30% and 31%, respectively. The overall classification accuracy of 52 ski-touring routes in Western Norway with a total length of 282 km increased from 55% in the model without forest information to 67% when utilizing canopy cover. The F1 score for the three predicted ATES classes improved by 31%, 9%, and 6%.
Authors
Bart Immerzeel Jan Vermaat Dennis Collentine Artti Juutinen Brian Kronvang Eva Skarbøvik Mette CarstensenAbstract
No abstract has been registered
Authors
Geir Wæhler Gustavsen Helge Berglann Elisabeth Jenssen Signe Kårstad Divina Gracia P. RodriguezAbstract
Urban agriculture is increasingly recognized as an important sustainable pathway for climate change adaptation and mitigation, for building more resilient cities, and for citizens’ health. Urban agriculture systems appear in many forms – both commercial and non-commercial. The value of the services derived from urban agriculture, e.g., enhanced food security, air quality, water regulation, and high level of biodiversity, is often difficult to quantify to inform policymakers and the general public in their decision making. We perform a contingent valuation survey of four different types of urban agriculture Where the citizens of Oslo are asked about their attitudes and willingness to pay non-commercial (urban community gardens and urban gardens for work training, education and kindergartens) and for commercial (i.e. aquaponics and vertical production) forms of urban agriculture. Results show that the citizens of Oslo are willing to increase their tax payments to contribute to further development of urban farming in Oslo.
Abstract
No abstract has been registered
Authors
Ruben Erik Roos Johan Asplund Tone Birkemoe Aud Helen Halbritter Rechsteiner Siri Lie Olsen Linn Vassvik Kristel van Zuijlen Kari KlanderudAbstract
No abstract has been registered
Authors
Arne Stensvand Natalia A. Peres David M. Gadoury Belachew Asalf Tadesse Aruppillai SuthaparanAbstract
No abstract has been registered
Authors
Jorge Aldea Ricardo Ruiz-Peinado Miren del Río Hans Pretzsch Michael Heym Gediminas Brazaitis Aris Jansons Marek Metslaid Ignacio Barbeito Kamil Bielak Gro Hylen Stig-Olof Holm Arne Nothdurft Roman Sitko Magnus LöfAbstract
1. Climate change is increasing the severity and frequency of droughts around the globe, leading to tree mortality that reduces production and provision of other ecosystem services. Recent studies show that growth of mixed stands may be more resilient to drought than pure stands. The two most economically important and widely distributed tree species in Europe are Norway spruce (Picea abies (L.) Karst) and Scots pine (Pinus sylvestris L.), but little is known about their susceptibility to drought when coexist. 2. This paper analyses the resilience (resistance, recovery rate and recovery time) at individual-tree level using a network of tree-ring collections from 22 sites along a climatic gradient from central Europe to Scandinavia. We aimed to identify differences in growth following drought between the two species and between mixed and pure stands, and how environmental variables (climate, topography and site location) and tree characteristics influence them. 3. We found that both the timing and duration of drought drive the different responses between species and compositions. Norway spruce showed higher vulnerability to summer drought, with both lower resistance and a longer recovery time than Scots pine. Mixtures provided higher drought resistance for both species compared to pure stands, but the benefit decreases with the duration of the drought. Especially climate sensitive and old trees in climatically marginal sites were more affected by drought stress. 4. Synthesis. Promoting Scots pine and mixed forests is a promising strategy for adapting European forests to climate change. However, if future droughts become longer, the advantage of mixed stands could disappear which would be especially negative for Norway spruce.
Authors
Bertold Mariën Dimitri Papadimitriou Titta Kotilainen Paolo Zuccarini Inge Dox Melanie Verlinden Thilo Heinecke Joachim Mariën Patrick Willems Mieke Decoster Aina Gascó Holger Lange Josep Peñuelas Matteo CampioliAbstract
Accurate estimations of phenophases in deciduous trees are important to understand forest ecosystems and their feedback on the climate. In particular, the timing of leaf senescence is of fundamental importance to trees’ nutrient stoichiometry and drought tolerance and therefore to trees’ vigor and fecundity. Nevertheless, there is no integrated view on the significance, and direction, of seasonal trends in leaf senescence, especially for years characterized by extreme weather events. Difficulties in the acquisition and analyses of hierarchical data can account for this. We collected four years of chlorophyll content index (CCI) measurements in thirty-eight individuals of four deciduous tree species (Betula pendula, Fagus sylvatica, Populus tremula and Quercus robur) in Belgium, Norway and Spain, and analyzed these data using generalized additive models for location, scale and shape (GAMLSS). As a result, (I) the phenological strategy and seasonal trend of leaf senescence in these tree species could be clarified for exceptionally dry and warm years, and (II) the daily average (air) temperature, global radiation, and vapor pressure deficit could be established as main drivers behind the variation in the timing of the senescence transition date. Our results show that the onset of the re-organization phase in the leaf senescence, which we approximated and defined as local minima in the second derivative of a CCI graph, was in all species mainly negatively affected by the average temperature, global radiation and vapor pressure deficit. All together the variables explained 89 to 98% of the variability in the leaf senescence timing. An additional finding is that the generalized beta type 2 and generalized gamma distributions are well suited to model the chlorophyll content index, while the senescence transition date can be modeled using the normal-exponential-student-t, generalized gamma and zero-inflated Box-Cox Cole and Green distributions for beech, oak and birch, and poplar, respectively.
Authors
Ola FlatenAbstract
Norwegian sheep production is based on the use of free outfield grazing resources in the mountains and forests in summer. Lamb prices are strongest at the beginning of the slaughter season in August and then begin to gradually decline, reaching a lower plateau in mid-October. Seasonal pricing provides incentives to get slaughter lambs to market early. The objective of this study was to examine how outfield summer pasture quality, time of collection from the outfields, and inclusion of annual forage crops in the diet of finishing lambs influence optimal farm plans and profitability in Norwegian forage-based sheep production systems at varying levels of farmland availability (varying from 15 to 25 ha with 20 ha as the basis). A linear programming model was developed for sheep production systems in the mountainous areas of Southern Norway. Input-output relationships incorporated into the model included data from field experiments with grasses for annual and perennial use, observed performance of lambs and ewes at pastures, a feed planning tool for the indoor season, and expert judgements. The model maximised total gross margin of farms with a housing capacity of 200 ewes. The results suggested that with more land available, drafting older and heavier lambs for slaughter was profitable. The lighter lambs at weaning were usually drafted much later and at the same or heavier carcass weights than the heavy lambs at weaning because of seasonal pricing. Higher quality outfield summer pastures increased lamb live weights at weaning. Annual profits improved considerably with rich summer pastures compared to poor summer pastures. Early collection was always less profitable than normal time of collection because greater prices for lambs sold could not offset losses from the additional feed costs incurred and a possibly smaller flock. Speeding up the growth rate of finishing lambs by offering annual forage crops in addition to grazed grass was usually more profitable than grass only. Only for rich summer pastures and normal time of collection at low land availability was use of annual forage crops unprofitable.