Hopp til hovedinnholdet

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.

2023

To document

Abstract

The aim of this study was to analyze the accuracy of predictions of dominant height, mean height, basal area, and volume from the nationwide forest attribute map (SR16). The analysis took advantage of field observations from 33 different forest inventory projects across Norway used for validation. Forest attributes for more than 5000 plots were predicted using non-stratified and stratified models of SR16 and the predictions were compared against corresponding ground reference values. Finally, the effect of different factors that might have influenced the prediction errors were analyzed using partial least squared regression (PLSR) to determine under which conditions the SR16 is less apt. The overall results across all plots were adequate (RMSE of 10%, MD of 2% for dominant and mean height; RMSE of 28%, MD of 4% for basal area; RMSE of 31%, MD of 5% for volume). However, when the accuracy was assessed locally for each inventory project, large differences in accuracy were observed. The MD% values for some inventory projects were substantial (>30% for basal area and volume). The results showed that stratification did not necessarily improve the results and that factors related to the forest structure had the greatest impact on the PLSR analysis.

To document

Abstract

Three lichen species, Fuscopannaria praetermissa, Lepraria borealis and Xanthomendoza fulva, are reported as additions to the biodiversity of the Gaupne area, Sogn og Fjordane, Norway. The fungal universal barcode DNA sequence (nrITS) is provided for Fuscopannaria praetermissa and Lepraria borealis. Results of preliminary molecular analyses indicate the need for a systematic revision of Lepraria borealis and other taxa in the L. neglecta group.

To document

Abstract

Introduction: Greenhouse tomato growers face the challenge of balancing fruit size and chemical quality traits. This study focused on elucidating the interplay between plant branching and light management on these traits, while maintaining consistent shoot density. Methods: We evaluated one- and two-shoot plants under varying top light intensities using high-pressure sodium lamps and light-emitting diode (LED) inter-lighting. Results: The reduced yield in the two-shoot plants was mainly due to smaller fruit size, but not due to source strength limitations, as evaluated through leaf weight ratio (LWR), chlorophyll index, specific leaf area (SLA), leaf dry matter percentage, and stem soluble carbohydrate accumulation. Enhanced lighting improved fruit weight and various fruit traits, such as dry matter content, total soluble carbohydrate content, and phenolic content, for both one- and two-shoot plant types. Despite lower mean fruit weight, two-shoot plants exhibited higher values for chemical fruit quality traits, indicating that the fruit growth of two-shoot plants is not limited by the available carbohydrates (source strength), but by the fruit sink strength. Diurnal analysis of fruit growth showed that two-shoot plants had reduced expansion during light transitions. This drop in fruit expansion was not related to changes in root pressure (measured as xylem sap exudation from decapitated plants), but might be related to diminished xylem area in the stem joint of the two-shoot plants. The concentration of several hormones, including cytokinins, was lower in two-shoot plants, suggesting a reduced fruit sink capacity. Discussion: The predominant impact of branching to two-shoot plants on sink capacity suggests that the fruit growth is not limited by available carbohydrates (source strength). Alongside the observation that light supplementation and branching exert independent additive effects on fruit size and chemical traits, this illuminates the potential to independently regulate these aspects in greenhouse tomato production.

Abstract

The Norwegian Institute of Bioeconomy Research (NIBIO) has been working on many fronts to promote sustainable agriculture. As part of the Department of Biogeochemistry and Soil Quality, I will present initiatives and progress made by the NIBIO Institute in promoting soil organic matter persistence and sustainable agriculture in Norway and worldwide. Two major challenges have been targeted with a focus on Norway: waste generation by several industries (e.g., agriculture, forestry, and fishery) and the short time of the cropping season in the country due to climatic constraints. To solve these issues, we are working on several projects focused on re-utilizing waste products by producing organic fertilizers, optimizing these fertilizers (e.g., biochar N-enrichment), and improving current cropping systems with crop diversification. Our main objective is to investigate the benefits of these practices in improving soil quality and crop productivity and enhancing soil organic matter persistence. Our work on soil science also goes beyond Norwegian and Nordic conditions. Among our international collaborations, we are currently working on a multi-institution bilateral project between China and Norway to promote the restoration of a semi-arid ecosystem in Inner Mongolia. We are also often engaging in project proposals for promoting sustainable agriculture in tropical regions. To develop these ideas, we promote a combined approach of spectroscopy techniques in collaboration with other institutions, such as nanoscale secondary ion mass spectrometry (NanoSIMS) in partnership with the Technical University of Munich (TUM) and NMR spectroscopy in partnership with the National Research Council of Italy (CNR-Pisa). Also, our research facilities count on good infrastructure, focusing on incubations with 13C and 15N labeled amendments and 13C pulse labeling.