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Publikasjoner

NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2024

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A well-defined methodology for constructing appropriate atomistic representations of biochar will aid in visualizing the structural features and elucidating biochar behavior with molecular dynamics (MD) simulations. Such knowledge will facilitate engineering biochars tailored to specific applications. To achieve this goal, we adapted modeling strategies applied in coal science by employing multi-cross-polarization 13C nuclear magnetic resonance, ultimate analysis, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy to identify functional groups. Helium density, surface area, and porosity were used to assess structural features. Biochar's aromatic cluster size distribution was proposed based on data from the benzene polycarboxylic acid method. The computational framework reduces bias by incorporating chemical information derived from density functional theory, reactive MD simulations, and advanced characterization data. The construction approach was successfully applied to cellulose biochars produced at four temperatures, obtaining independent representations with a relative error on the atomic contents of <10 % for oxygen and nitrogen and <5 % for carbon and hydrogen. The atomistic representations were validated using X-ray diffraction, electron spin resonance data, and laser desorption/ionization Fourier-transform ion cyclotron resonance-mass spectrometry. The code will assist others in overcoming structural creation barriers and enable the utilization of the generated structures for further simulations.

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One of the major challenges facing agricultural and food systems today is the loss of agrobiodiversity. Considering the current impasse of preventing the worldwide loss of crop diversity, this paper highlights the possibility for a radical reorientation of current legal seed frameworks that could provide more space for alternative seed systems to evolve which centre on norms that support on-farm agrobiodiversity. Understanding the underlying norms that shape seed commons are important, since norms both delimit and contribute to what ultimately will constitute the seeds and who will ultimately have access to the seeds and thus to the extent to which agrobiodiversity is upheld and supported. This paper applies a commoning approach to explore the underpinning norms of a Swedish seed commons initiative and discusses the potential for furthering agrobiodiversity in the context of wider legal and authoritative discourses on seed enclosure. The paper shows how the seed commoning system is shaped and protected by a particular set of farming norms, which allows for sharing seeds among those who adhere to the norms but excludes those who will not. The paper further illustrates how farmers have been able to navigate fragile legal and economic pathways to collectively organize around landrace seeds, which function as an epistemic farming community, that maintain landraces from the past and shape new landraces for the present, adapted to diverse agro-ecological environments for low-input agriculture. The paper reveals how the ascribed norms to the seed commons in combination with the current seed laws set a certain limit to the extent to which agrobiodiversity is upheld and supported and discusses why prescriptions of “getting institutions right” for seed governance are difficult at best, when considering the shifting socio-nature of seeds. To further increase agrobiodiversity, the paper suggests future seed laws are redirected to the sustenance of a proliferation of protected seed commoning systems that can supply locally adapted plant material for diverse groups of farmers and farming systems.

Sammendrag

Hurdal (NO-Hur) is a recently labelled ICOS class 2 station in Southeast Norway. It represents a typical southern boreal forest of medium productivity, dominated by old Norway spruce (average tree height: 25 m, ages: up to 100 years) with some pine and broadleaved trees. The eddy covariance technique is used to measure CO2 fluxes on a 42 m tower since 2021 . The measurements have an average footprint area of approximately 63 ha. In 2023, the region experienced an unusual dry spring and then an extraordinary flood in August. Both events showed significant impact on the Net Ecosystem Exchange (NEE) and heat fluxes. The station is also equipped with automatic dendrometers and sap flow devices on the dominant spruce trees, allowing us to investigate the impact of these events at the individual tree scale. We will present tree growth and transpiration flux at different temporal scales (from sub-daily to seasonal), and relate these single tree observations with environmental variables, ecosystem-level NEE and evapotranspiration using phase synchronization analysis. These observational data will yield insights into carbon and water processes of a boreal forest at different scales in response to multiple disturbances.

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1. Sap flow measurements are fundamental to understanding water use in trees and could aid in predicting climate change effects on forest function. Deriving knowledge from such measurements requires empirical calibrations and upscaling methods to translate thermometric recordings to tree water use. Here, we developed a user-friendly open-source application, the Sap Flow Analyzer (SFA), which estimates sap flow rates and tree water use from the heat field deformation (HFD) instruments. 2. The SFA incorporates four key features to ensure maximum accuracy and reproducibility of sap flow estimates: diagnosis diagrams to assess data patterns visually, regression models implemented to increase accuracy when estimating K (the main HFD parameter), three approaches to upscale sap flow rates to whole-tree water use and visualization of the input parameters' uncertainty. Thirteen participants were given three raw datasets and assigned data processing tasks using the SFA user guide, from estimating sapwood depth to scaling sap flow rates to whole-tree water use to assess the reproducibility and applicability of the SFA. 3. Participants' results were reasonably consistent and independent of their background in using the SFA, R, or HFD method. The results showed lower variability for high flow rates (SD: mean 1% vs. 10%). K estimates and sapwood depth differentiation were the primary sources of variability, which in turn was mainly caused by the user's chosen scaling method. 4. The SFA provides an easy way to visualize and process sap flow and tree water use data from HFD measurements. It is the first free and open software tool for HFD users. The ability to trace analysis steps ensures reproducibility, increasing transparency and consistency in data processing. Developing tools such as the SFA and masked trials are essential for more precise workflows and improved quality and comparability of HFD sap flow datasets.