Norwegian Institute of Bioeconomy Research

The capacity of nutrient-limited forests to enhance carbon (C) sequestration under elevated CO2 (eCO2) remains a critical uncertainty in C cycle modeling. While existing evidence suggests that low phosphorus (P) bioavailability may constrain CO2 fertilization effects on plant growth, the extent to which this limitation modulates ecosystem responses to eCO2 in forests adapted to P-deficient soils remains poorly understood. Here, using eight P-enabled models, we simulated the magnitudes and mechanisms through which P bioavailability interacts with eCO2, emulating an ecosystem-scale P enrichment experiment at a P-limited Eucalyptus forest undergoing long-term Free-Air CO2 Enrichment. While models predicted pronounced P effects on tree growth, P enrichment unexpectedly did not increase the CO2 effects on tree growth and ecosystem C sequestration. Models prioritized either CO2-driven or P-driven growth, but rarely both. This tradeoff emerged due to model-specific assumptions on 1) partitioning of the extra P in soil labile versus nonlabile pools; 2) plant photosynthetic acclimation to P deficiency; 3) C and nutrient use strategies regulating plant size and allocation; and 4) microbial-driven soil decomposition processes. By generating divergent yet biologically plausible outcomes, these predictions establish critical testable hypotheses for empirical research and highlight multiple P-related pathways that may influence the future land C sink.

Abstract Introduction The use of Saccharomyces cerevisiae to ferment alcoholic beverages is an ancient tradition, with genetic evidence indicating origins in Neolithic Asia, although the domestication process of the species is not fully understood. Kveik is a group of traditional yeasts used in farmhouse brewing in western Norway preserved through generations of rural brewing practice. While recent studies have highlighted the distinctiveness of kveik, its precise phylogenetic position, genetic diversity, and domestication history remain unclear. Results We performed whole-genome sequencing on 62 samples representing 25 unique Norwegian strains selected using cultural heritage criteria, and generated telomere-to-telomere (T2T) assemblies for representative isolates. Phylogenomic and population genetic analyses reveal that kveik forms a paraphyletic and early diverging group with respect to other domesticated S. cerevisiae strains. Most strains exhibit low within-strain diversity, strong geographic clustering, and little evidence of gene-flow or admixture. Mitochondrial genomes and Ty1 retrotransposon profiles corroborate this distinct lineage history. We further show that previously reported signals of gene flow between kveik and Asian fermentation strains are likely artifacts caused by population structure and selection. Divergence time estimates suggest that the common ancestor of beer, kveik, and other liquid-phase fermenting strains originated from ancestral populations 4,000 to 8,000 years ago. Conclusion Kveik yeasts represent a relic of early S. cerevisiae domestication, shaped by ancient human practices, migrations, and the spread of agriculture. Our genomic resource sheds light on yeast evolution and domestication. They likely comprise some of the oldest domesticated lineages in continuous use until today, connecting endangered intangible cultural heritage to an early genetic origin.

Water plays a central connecting role within the climate system, linking meteorological, hydrological, and earth system processes with societal dimensions such as water resource demands and risks associated with pollution, droughts, and floods. Global water challenges are addressed through multiple international agendas related to sustainable development, climate change, biodiversity, and water security. While these agendas share broadly aligned objectives, they differ in scope, scale, and modes of operationalization. Together, they shape how scientific knowledge is mobilized, policies are formulated, and actions are implemented. As the 2030 Agenda approaches its conclusion, there is a growing need to review and map global water agendas in order to better understand their interactions and support more coherent responses to complex water challenges.Rather than viewing global water agendas as parallel and independent efforts, they can be understood as interconnected learning pathways through which shared objectives, knowledge, and practical experience evolve over time. From this perspective, synergies emerge across these learning pathways through reflection, coordination, and exchange between science, policy, and practice. Clarifying how such synergies can be recognized, supported, and strengthened is therefore essential for advancing more integrated and impactful responses to global water challenges.The Strategic UN Synergy Working Group (SUN) operates within the IAHS HELPING Science for Solutions Decade (2023–2032) and aims to strengthen the contribution of hydrological science to international policy processes and practical implementation programmes. Guided by the HELPING paradigm, SUN facilitates bottom-up engagement, open science, and co-creation principles to support learning across scales and the translation of hydrological knowledge into policy and action.This contribution introduces the vision, structure, and core activities of the SUN Working Group, with a focus on understanding global water agendas and supporting synergies through a science–policy–practice approach. SUN builds on the understanding of global water agendas as interconnected learning pathways, and we will illustrate how coordinated learning pathways can help advance more coherent, integrated, and future-oriented global water agenda.

Soils are central to environmental sustainability and human well-being, yet they remain underrepresented in higher education and insufficiently addressed in societal awareness. With more than 60% of European soils affected by degradation, there is an urgent need for educational strategies to help reverse this trend. Within this context, the CURIOSOIL (URL: curiosoil.eu) project implements an integrated educational approach built on the Soil Literacy Assessment Framework (SLAF), which conceptualises soil literacy across four domains of knowledge, attitudes, and skills, operationalised through defined subdomains, descriptors, and learning outcomes. The SLAF provides a common structure for both the design of educational resources and the assessment of learning processes. Guided by this framework, a range of educational resources is being developed across different educational levels.For higher education, CURIOSOIL will implement four complementary approaches: (1) ready-to-use lesson plans for higher education teaching, including discipline-targeted materials to support integration of soil topics into non-soil standard curricula (2) a Massive Open Online Course (MOOC) as a scalable learning environment designed to raise soil awareness and strengthen soil knowledge in higher education; (3) challenge-based learning activities that engage learners in authentic, societally relevant soil-health challenges; and (4) short online micro-credentials designed to deepen soil health knowledge. Together, these approaches address complementary dimensions of science communication, spanning soil knowledge acquisition, reflection, participation, and action-oriented learning. These activities are guided by CURIOSOIL’s Theory of Change (ToC), which defines long-term goals for assessing change in soil literacy and articulates how targeted educational resources and learning activities are expected to contribute to societal changes towards caring for soil and produce impact.The main goal of this study is to analyse how different higher education learning environments, designed under the Soil Literacy Assessment Framework and CURIOSOIL’s Theory of Change, contribute to improving soil literacy and fostering responsible soil stewardship among higher education students. In this presentation we will discuss the impact of the four complementary educational approaches of CURIOSOIL to identify which approaches are most effective for specific dimensions of soil literacy. We will investigate how scalable (MOOCs), immersive (CBL), and modular (micro-credentials) learning environments support distinct but complementary soil literacy processes and discuss how these could facilitate the integration of soil topics into non-soil-focused degree programmes. This study is expected to generate data-driven insights into how soil literacy can be designed, measured, and scaled in higher education.ACKNOWLEDGEMENTSThe authors acknowledge co-funding from the European Union under the Horizon Europe Programme, through the project CURIOSOIL Grant Agreement No. 101112875 and the financial support of CESAM (UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020) by FCT/MCTES, through national funds. We also thank project partners for their contributions.

Mineral-associated organic matter (OM) exhibits a heterogeneous arrangement in soils at the microscale and nanoscale as revealed by high-resolution imaging techniques. The arrangement of OM at the microscale has broad implications for biogeochemical cycles of major elements such as C and N by compartmentalizing their dynamics into distinct micropatches and a few µm-sized hotspots. It is crucial to understand the organization of this heterogeneous microscale arrangement across diverse soil systems. Here, we present a meta-analysis of spatial patterns of OM patches based on unsupervised segmentation of nanoscale secondary ion mass spectrometry (NanoSIMS) measurements. Using a dataset of over 450 measurements of fine fractions from soils with different texture and C content, we evaluated the spatial coverage, clustering, and heterogeneity of OM micropatches across mineral surfaces. The OM coverage across mineral surfaces linearly correlated with the bulk soil C content, indicating a spatially expanding arrangement of OM whereas large parts of mineral-dominated surface remain. Higher OM coverage was related to more connected and more clustered OM patches. Within the OM patches, we found evidence of recurring µm-sized distinct C-rich and N-rich subunits based on a fractal geography approach. Within more homogeneous OM patches, subunits showed stronger differentiation in C and N composition, whereas subunits within more heterogeneous patches exhibited less differentiated C and N composition. The distinct spatial organization of OM micropatches observed here suggests a compartmentalized framework of OM dynamics with implications for C and N cycling in soils.

The spread of antibiotic resistance genes (ARGs) through horizontal gene transfer (HGT) poses a serious risk to public health. Natural transformation of extracellular ARGs (eARGs) to bacterial competent cells is a HGT pathway, but its frequency in soil and the influencing factors remain largely unknown. Here, we show that organic fertiliser amendment significantly increased the transformation frequency of plasmid-borne eARGs to both the model species Acinetobacter baylyi ADP1 inoculated into a sterile soil and to diverse native bacteria in an unsterile soil. During incubation in unsterile soil, eARGs were transformed into six bacterial phyla, especially Pseudomonadota and Actinobacteria, including opportunistic pathogens in the genera Stenotrophomonas, Acinetobacter and Pseudomonas. Most (87.5%) of the detected transformants belong to bacterial taxa previously unknown to be capable of acquiring extracellular DNA by natural transformation. Organic fertiliser amendments, likely through enriched metals (e.g., Mn and Zn), promoted reactive oxygen species (ROS) production, triggered oxidative stress responses, increased membrane permeability and ATP synthesis and enhanced bacterial competence for the uptake of eARGs. Our findings indicate that natural transformation of eARGs represents an important HGT pathway in soils and organic fertiliser additions can substantially promote the eARG spreads within the soil bacterial community through natural transformation.

Abstract The expression of plant defensive traits against herbivores often incurs costs to other essential functions, such as growth and reproduction. Understanding how selection acts on putatively functional traits that are expected to trade off across space and time is therefore critical for predicting evolutionary responses to ongoing and future environmental change. Here, we used multiple replicated genotypes of woodland strawberry ( Fragaria vesca ; Rosaceae) grown over two years in three outdoor common gardens in Spain, Belgium, and Sweden. In each garden, genotypes were exposed to both a reduced-precipitation treatment simulating drought and an ambient precipitation treatment. We estimated directional and correlational selection on rosette diameter (a proxy for growth) and herbivore resistance (measured as the inverse of chewing damage) using fruit and stolon production as proxies for sexual and asexual fitness across all environments (i.e., every site × year × treatment combination). We then combined selection gradients with environment-specific genetic (co)variance among genotypes to quantify the expected response to selection (Δz = Gβ ) and to identify covariance-driven constraints or facilitation therein. Selection consistently favored larger rosette diameter for both fitness proxies across nearly all environments, which, in combination with genetic covariances among genotypes, resulted in a general evolutionary response toward increased rosette diameter, with the strongest response at the wettest site (Belgium). In contrast, selection on resistance and the corresponding among-genotype evolutionary responses were strongly context-dependent. Correlational selection on rosette diameter × resistance occurred in only a few environments, primarily under reduced precipitation. Environment-dependent genetic covariances constrained or facilitated selection on both traits only at the site with the highest herbivory (Sweden) under drought conditions. Overall, our results reveal a context-dependent interplay between selection and genetic architecture, underlining the difficulty of predicting evolutionary trajectories under environmental change, and highlighting how spatially and temporally variable conditions may maintain standing genetic variation in plant traits.

Abstract Rearing conditions play a crucial role in shaping the life-history traits of arthropods, yet the combined effects of rearing environment and prey availability within and across generations remain poorly understood. This study investigated how rearing cell size (large vs small) and prey availability (30 vs 60 Carpoglyphus lactis eggs per day) influence the performance of the predatory mite Amblyseius herbicolus and its offspring under controlled laboratory conditions. Within the maternal generation, individuals confined to small cells consumed significantly more prey but showed no improvement in development, survival, or adult size, indicating stress-related increases in energy expenditure. High prey availability enhanced survival rate, and its interaction with cell size revealed that high prey availability mitigated the negative effects of stress. Under high prey availability, mothers in small cells produced remarkably larger eggs, suggesting altered reproductive investment under stress. Across generations, offspring of mothers reared under low prey availability and small rearing cell size showed higher survival and larger adult size, reflecting compensatory maternal effects. These findings partially support the hypothesis that restricted rearing environments and low prey availability negatively affect within-generation performance but promote adaptive transgenerational responses, providing new insight into maternal effects and rearing optimisation in phytoseiid predators.

In semiarid regions, soil organic carbon (SOC) stocks and soil organic matter (SOM) pools are often low due to limited biomass input and inadequate management. This study evaluated SOC stocks and SOM fractions in a forage cactus–sorghum intercropping system irrigated with treated sewage water under diverse mulch in the northeastern Brazilian semiarid. The experiment followed a randomized split-plot block design with four replicates. Main plots included four irrigation levels (0, 80, 100, and 120 % of sorghum evapotranspiration (ETc)), and split plots comprised two mulch treatments: no mulch (NM) and mulch (WM) with 8 Mg ha −1 of sabi grass, spiny burrgrass, and goosegrass. Soil samples were collected at 0–0.10, 0.10–0.20, and 0.20–0.40 m depths in three sorghum cuts to determine labile SOM fractions: hot water-extractable C (HWEO-C), potassium permanganate-oxidizable C (POX-C), and particulate organic C (POC). In addition, SOC stocks and humic substances (HS), including humin (HU), fulvic acid (FA), and humic acid (HA), were determined at the end of the experiment. Intercropping system productivity was also evaluated. The highest SOC, POC, POX-C, and HWEO-C stocks occurred in 80WM and 100WM treatments, especially in HS, with HU as the dominant component. SOC in the HU fraction exceeded that in native vegetation soils, with threefold increases at 0–0.10 m and six-to sevenfold increases in deeper layers. Soils without irrigation, regardless of mulch, exhibited lower C storage, underscoring the importance of water management. Combining reclaimed water irrigation and mulching enhanced SOC accumulation, particularly in stable humic fractions, boosted carbon sequestration and crop productivity, and fostered sustainable, climate-resilient agriculture in semiarid tropical regions. • Reclaimed water increases soil carbon stocks in the semiarid region. • Mulch and reclaimed water synergistically increase C accumulation in SOM pools. • The combination of reclaimed water and mulch improves forage sorghum yield. • Irrigation at 80–100 % ETc boosted humic C stocks in tropical semiarid soils.