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.
2013
Authors
Xueli Chen Marianne Bechmann Johannes Deelstra Lillian Øygarden Lei Zhang Yufeng Wang Baoku Zhou Xingzhu Ma Dan WeiAbstract
No abstract has been registered
Authors
Eivind UlebergAbstract
No abstract has been registered
Authors
Audun Helge Nerland Per Brandtzæg Merethe Aasmo Finne Askild Lorentz Holck Olavi Junttila Heidi Sjursen Konestabo Richard Meadow Kaare Magne Nielsen Ville Erling Sipinen Hilde-Gunn Opsahl Sorteberg Rose Vikse Åshild Kristine AndreassenAbstract
No abstract has been registered
Authors
Audun Helge Nerland Per Brandtzæg Merethe Aasmo Finne Askild Lorentz Holck Olavi Junttila Heidi Sjursen Konestabo Richard Meadow Kaare Magne Nielsen Ville Erling Sipinen Hilde-Gunn Opsahl Sorteberg Rose Vikse Åshild Kristine AndreassenAbstract
No abstract has been registered
Authors
Audun Helge Nerland Per Brandtzæg Merethe Aasmo Finne Askild Lorentz Holck Olavi Junttila Heidi Sjursen Konestabo Richard Meadow Kaare Magne Nielsen Ville Erling Sipinen Hilde-Gunn Opsahl Sorteberg Rose Vikse Åshild Kristine AndreassenAbstract
No abstract has been registered
Authors
Åshild Kristine Andreassen Per Brandtzæg Merethe Aasmo Finne Askild Lorentz Holck Anne Marthe Jevnaker Olavi Junttila Heidi Sjursen Konestabo Richard Meadow Kaare Magne Nielsen Monica Sanden Rose Vikse Hilde-Gunn Opsahl SortebergAbstract
No abstract has been registered
Authors
Nicholas ClarkeAbstract
No abstract has been registered
Authors
Katharina Bäutigam Kelly J. Vining Clément Lafon-Placette Carl Gunnar Fossdal Marie Mirouze José Gutiérrez Marcos Silvia Fluch Mario Fernández Fraga M. Ángeles Guevara Dolores Abarca Øystein Johnsen Stéphane Maury Steven H. Strauss Malcolm M. Campbell Antje Rohde Carmen Díaz-Sala María-Teresa CerveraAbstract
Epigenetic variation is likely to contribute to the phenotypic plasticity and adaptative capacity of plant species, and may be especially important for long-lived organisms with complex life cycles, including forest trees. Diverse environmental stresses and hybridization/polyploidization events can create reversible heritable epigenetic marks that can be transmitted to subsequent generations as a form of molecular “memory”. Epigenetic changes might also contribute to the ability of plants to colonize or persist in variable environments. In this review, we provide an overview of recent data on epigenetic mechanisms involved in developmental processes and responses to environmental cues in plant, with a focus on forest tree species. We consider the possible role of forest tree epigenetics as a new source of adaptive traits in plant breeding, biotechnology, and ecosystem conservation under rapid climate change.
Authors
Peder GjerdrumAbstract
Precise dating of the year of felling is one intended outcome of dendrochronology. However, occasionally some or all sapwood rings might be missing, either due to deterioration or because they were carved off, or for some other reason. Consequently, while heartwood is preserved, sapwood might be fully or partially missing. In such cases, the year of felling must be estimated by adding a suitable number of sapwood rings. A heartwood age rule (HAR) has been advocated for Scots pine and adapted to European larch and Cembra pine, implying a linear relationship between sapwood ring count and the square root of heartwood ring count, largely irrespective of position in the stem. The same rule applied to all observations of a species, irrespective of silviculture, location or fertility of the growth site. Scots pine had twice or thrice as many sapwood rings as Cembra pine, which had 10% more rings than larch. The magnitude of model residuals was proportional to estimated sapwood ring count. Relative residuals were roughly normally distributed. To be applicable in Bayesian modelling in dendrochronology analyses, detailed information on model errors has been provided.
Abstract
Many remote sensing-based methods estimating forest biomass rely on allometric biomass models for field reference data. Terrestrial laser scanning (TLS) has emerged as a tool for detailed data collection in forestry applications, and the methods have been proposed to derive, e.g. tree position, diameter-at-breast-height, and stem volume from TLS data. In this study, TLS-derived features were related to destructively sampled branch biomass of Norway spruce at the single-tree level, and the results were compared to conventional allometric models with field measured diameter and height. TLS features were derived following two approaches: one voxel-based approach with a detailed analysis of the interaction between individual voxels and each laser beam. The features were derived using voxels of size 0.1, 0.2, and 0.4 m, and the effect of the voxel size was assessed. The voxel-derived features were compared to features derived from crown dimension measurements in the unified TLS point cloud data. TLS-derived variables were used in regression models, and prediction accuracies were assessed through a Monte Carlo cross-validation procedure. The model based on 0.4 m voxel data yielded the best prediction accuracy, with a root mean square error (RMSE) of 32%. The accuracy was found to decrease with an increase in voxel size, i.e. the model based on the 0.1 m voxel yielded the lowest accuracy. The model based on crown measurements had an RMSE of 34%. The accuracies of the predictions from the TLS-based models were found to be higher than from conventional allometric models, but the improvement was relatively small.