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.
2017
Authors
Isabella Børja Kjell Andreassen Jan Čermák Lise Dalsgaard Arthur Gessler Douglas L. Godbold Rainer Hentschel Zachary E. Kayler Paal Krokene Nadezhda Nadezhdina Sabine Rosner Svein Solberg Halvor Solheim Jan Svetlik Mari Mette Tollefsrud Ole Einar TveitoAbstract
No abstract has been registered
Authors
Olalla Díaz-Yáñez Blas Mola-Yudego José Ramón González-Olabarria Timo PukkalaAbstract
The risk of snow and wind damage should be considered when deciding forest management actions, as it can greatly change forest development and its accompanying services. In this study, we develop models that predict snow and wind damage using management related variables as predictors. The plot level models are based on the extensive data available for Norwegian forests from four consecutive measurements of the national forest inventory along the period 1995–2014. The snow and wind risk is assessed in pure stands (pine, spruce and birch) as well as for mixed stands. Separate models are constructed for predicting the probability of a tree to be damaged, broken or uprooted. The models’ descriptors include: mean diameter, mean tree slenderness, mean height, basal area and a portfolio of variables related to stand structure and composition. The models are based on generalized linear models assuming binomial or quasi-binomial distributions resulting in nine models. Mixed stands are the stands most commonly affected by snow and wind damage followed by spruce dominated stands. Spruce stands with more heterogeneous structures are less prone to suffer breakage of trees, and increasing stand height have a big impact on the risk of tree breakage. The models presented in this study can be used to create management prescriptions considering the risk of snow and wind damage. These models also help to better understand which variables make a forest more vulnerable to snow and wind damage.
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Authors
Lampros LamprinakisAbstract
Organizational development, change and adaptation are complex and challenging tasks that have been widely studied and debated, spanning from general change models and theories on organizational change, to change management theory and strategy literature. Even though issues surrounding organizational change have been extensively studied, the estimated success rates remain particularly low, thus keeping this kind of studies high in the research agenda. This article examines organizational change and adaptation in the context of institutional change. More specifically, the article examines the case of Valio, the biggest Finnish dairy company, and its reorganization and restructuring during the period surrounding Finland’s assessment to the EU in 1995. Valio’s case is particularly interesting since it involves a well-established “national institution”, with rich history and significant economic contribution to the national economy. The purpose of this paper is to explore how Valio’s managers perceived the organizational change efforts surrounding the period of EU accession and what change practices were followed. In doing so, the analysis adopts the comprehensive qualitative case study methodology having a descriptive and explorative approach. This approach involves several in-depth interviews with key Valio executives, stakeholders, and industry insiders. The analysis maps and identifies key themes and processes that characterized the change strategy and allowed for the successful organizational change.
Authors
Michela Zanetti Corrado Costa Rosa Greco Stefano Grigolato Giovanna Ottaviani Aalmo Raffaele CavalliAbstract
The quality requirements of wood biofuels are regulated by a series of harmonized international standards. These standards define the technical parameter limits that influence the quality of solid biomass as a fuel. In 2014 the European reference standard for solid biofuel was replaced by the International ISO standard. In the case of wood chips, the main difference between the European and International standards is the definition of particle size distribution classes. In this context, this study analyses the quality of wood chips and its variation over the years according to the “former” (EN 14691-4) and “in force” (ISO 17225-4) standards. A Soft Independent Modelling of Class Analogy (SIMCA) model was built to predict the best quality of wood chips and to clarify the relationship between quality and standard parameters, time and changes in the standard regulations. The results show that, compared to the EN standards, classification with the ISO standards increases the samples belonging to the best quality classes and decreases the not classified samples. Furthermore, all the SIMCA models have a high sensitivity (>90%), reflect the differences introduced to the quality standards and are therefore suitable for monitoring the quality of wood chips and their changes.
Abstract
The nature of subsurface flow depends largely on hydraulic conductivity of the vadoze zone, the permeability of the underlying bedrock, the existence of soil layers differing in hydraulic properties and macropore content, soil depth and slope angle. Quantification of flow pathways on forested hillslopes is essential to understand the hydrological dynamics and solute transport patterns. Acrisols, with their argic Bt horizons, are challenging in this respect. To increase the understanding of flow pathways of water and the short-term variability of the soil moisture patterns in Acrisols, a field study was conducted on a forested hillslope in the Tie Shan Ping (TSP) watershed, 25 km northeast of Chongqing city, PR China. This catchment is covered by mixed secondary forest dominated by Masson pine (Pinus Massoniana). The soil's Ksat reduced significantly at the interface between the AB and Bt horizons (2.6E-05 versus 1.2E-06 m s−1). This led to that the flow volume generated in the Bt horizon was of little quantitative importance compared to that in the AB horizon. There was a marked decrease in porosity between the O/A horizon and the AB horizon, with a further decrease deeper in the mineral subsoil. Especially the content of pores >300 µm were higher in the AB horizon (14.3%) compared to the Bt horizon (6.5%). This explains the difference in Ksat values. Our study shows that Bt horizons have limited water transport capability, forcing part of the infiltrated rainwater as interflow through the OA and AB horizons. The topsoil thus responds quickly to rainfall events, causing frequent cycles of saturation and aeration of soil pores
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In this study, we investigated the potential of airborne imaging spectroscopy for in-season grassland yield estimation. We utilized an unmanned aerial vehicle and a hyperspectral imager to measure radiation, ranging from 455 to 780 nm. Initially, we assessed the spectral signature of five typical grassland species by principal component analysis, and identified a distinct reflectance difference, especially between the erectophil grasses and the planophil clover leaves. Then, we analyzed the reflectance of a typical Norwegian sward composition at different harvest dates. In order to estimate yields (dry matter, DM), several powered partial least squares (PPLS) regression and linear regression (LR) models were fitted to the reflectance data and prediction performance of these models were compared with that of simple LR models, based on selected vegetation indices and plant height. We achieved the highest prediction accuracies by means of PPLS, with relative errors of prediction from 9.1 to 11.8% (329 to 487 kg DM ha−1) for the individual harvest dates and 14.3% (558 kg DM ha−1) for a generalized model.