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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.

2019

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Abstract

We present a game-theoretical model arguing that greater public transparency does not necessarily lead to higher social welfare. Political agents can benefit from providing citizens with misleading information aimed at aligning citizens’ choices with the political agents’ preferences. Citizens can lose from being fooled by political agents, though they can mitigate their losses by conducting costly inspections to detect false information. Producing and detecting false information is costly and can reduce social welfare.

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Abstract

Flowering performance and phenology of six new pear cultivars of Nordic origin were examined during a 12 year period. The seasonal timing of shoot growth and flower initiation were monitored in three years. The morphological floral stages of the flower bud formation process were examined for the cultivar ‘Celina’. Seven floral stages were identified and described. The date of full bloom varied between years as a function of the currently accumulated heat sum in early spring. Still, the earliness ranking of the cultivars was consistent across years for both flower initiation and blooming. The cultivars ‘Anna’ and ‘Ingeborg’ consistently initiated floral primordia 2–3 weeks earlier than ‘Celina’, ‘Clara Frijs’, ‘Fritjof’ and ‘Kristina’, and this was accompanied with 4–5 days earlier blooming in the following spring. The early flower initiation cultivars ‘Anna’ and ‘Ingeborg’ also had richer flowering than the late-blooming cultivars. ‘Fritjof’ was identified as a suitable pollinator for ‘Celina’ in the Nordic climate. Comparison of the flowering phenology of pear and apple cultivars showed that while the pears, on average, flowered a week ahead of the apples, they initiated flower primordia almost two weeks later, thus rendering the intervening period approximately three weeks longer in pear than in apple

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Abstract

Aim Root growth strategies may be critical for seeding survival and establishment under dry conditions, but these strategies and their plasticity are little known. We aim to document the ability of young grass seedlings to adjust their root system architecture, root morphology and biomass allocation to roots to promote water uptake and survival under progressive drought. Methods Seedlings growing in columns filled with sand and exposed to drought or well-watered controls were repeatedly harvested for determination of biomass fractions, root length, −architecture and -morphology in a greenhouse experiment. Allometric scaling exponents and standardised major axis regression were used to investigate allocation patterns. Results Young seedlings were able to sustain leaf turgor and functions during eight weeks of progressive drought through phenotypic plasticity of the primary root system producing deeper and simpler roots. Biomass allocation to roots decreased or did not respond, and other components of root morphology showed only moderate plasticity. Conclusion Our results suggest that morphological and architectural plasticity of the primary root system may well be key features for dehydration avoidance and survival in grass seedlings under moderate drought when allocation of biomass to roots and development of secondary roots are constrained.

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Abstract

Snow and wind damages are one of the major abiotic disturbances playing a major role in forest ecosystems and affecting both stand dynamics and forest management decisions. This study analyses the occurrence of wind and snow damage on Norwegian forests, based on data from four consecutive forest inventories (1995–2014). The methodological approach is based on boosted regression trees, a machine learning method aiming to demonstrate the effects of different variables on damage probability and their interactions as well as to spatialize damage occurrence to make predictions. In total, 313 models are fitted to detect trends, interactions and effects among the variables. The main variables associated with damage occurrence are consistent across all the models and include: latitude, altitude and slope (related to site and location), and tree density, mean diameter and height (related to forest characteristics). The results show that stand dominant height is a key variable in explaining damage probability, whereas stand slenderness has a limited effect. More heterogeneous forest structures make birch dominated stands more resistant to damage. Finally, the models are translated into occurrence maps, to provide landscape-level information on snow and wind damage hazard. Further application of the models can be oriented towards assessing the probability of damage for alternate stand management scenarios.