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• Bøe, Frederik; Inagaki, Thiago Massao; Sturite, Ievina; Aas, Anders Bjørnsgaard; Schaik, Loes van & Stolte, Jannes (2026). The role of undersown cover crops for improving P cycling in high latitudes arable soils. Plant and Soil. ISSN 0032-079X. 520, p. 703–717. doi: 10.1007/s11104-026-08276-2. Full text in Research Archive Show summary

  Background and Aims Efficient phosphorus (P) and management is essential for sustainable arable systems. Cover crops (CCs) are promising, but their performance is uncertain in high-latitudes. This three-year study evaluated CCs’ effects on P dynamics in a P-rich soil undersown in barley in Mid-Norway (63.9°N)—one of the northernmost trials of its kind. Methods A randomized complete block design included three CC treatments: ryegrass (CC1), a ryegrass–clover mix (CC2), and a four species mix including grass, legumes and herbs (CC3), and controls without CC (with/without NPK fertilizer). Soil and plant analyses included total and available P, total N, potentially mineralizable N (PMN), pH, permanganate-oxidizable carbon, root biomass, plant P concentrations, and microbial abundance via qPCR. Statistical analysis was based on Linear Mixed Models (LMMs). Results Cover crops successfully established (average biomass: 1525 kg ha⁻ 1 ), accumulated ~ 7 kg P ha⁻ 1 , and did not reduce barley yields. LMMs showed significant effects of CC treatment on root biomass, total P, and bacteria. Pairwise comparisons also revealed that fungal abundances in CC1 and CC3 were significantly higher than in the unfertilized control. Pairwise regression revealed that soil total P was strongly predicted by root biomass (β = 1.37, P < 0.001). Available P was negatively controlled by microbial pools (Bacteria: β = -9.22, P < 0.001) and residue quality (C:P ratio: β = -0.36, P < 0.001). Conclusions CCs can be used at 63°N without yield penalty. The primary P mechanism is mass-driven sequestration (root biomass) into the stable total P pool. However, P availability is temporally constrained by residue quality and microbial competition.

• Inagaki, Thiago Massao; Bøe, Frederik; Sturite, Ievina; Budai, Alice Erzebet; Aas, Anders Bjørnsgaard & Rasse, Daniel (2026). Root development as a driver of mineral-associated organic matter formation in cover crop systems of high-latitude agriculture. Agriculture, Ecosystems & Environment. ISSN 0167-8809. 396. doi: 10.1016/j.agee.2025.109968. Full text in Research Archive Show summary

  Cover crops enhance soil quality and organic matter stability, yet the mechanisms linking belowground inputs to persistent soil organic matter (SOM) remain unclear. This study examined the effects of diversified cover cropping in barley systems on root biomass, SOM fractions, soil structure, microbial activity, and yield in central Norway (63.9° N), three years post-implementation. Six treatments were tested: (1) Control (barley without NPK), (2) Biochar-Fertilizer (barley + NPK + 3 Mg ha⁻¹ biochar), (3) Monocrop (barley), (4) Ryegrass (barley + ryegrass), (5) Clover (barley + ryegrass + white/red clover), and (6) Chicory (barley + ryegrass + red clover + chicory + bird’s-foot trefoil). Ryegrass and Clover systems produced 28.65 g m-² more root biomass at 0–13 cm (p < 0.05) and, along with Monocrop, stored 2.2 Mg ha-¹ more mineral-associated organic matter (MAOM) carbon and 0.2 Mg ha-¹ more MAOM nitrogen at 0–20 cm than other treatments. The Chicory system improved soil structure and biology, with higher aggregate stability, lower bulk density, and greater microbial abundance. Barley yields remained consistent across treatments, suggesting that cover cropping and low biochar inputs do not reduce productivity. Strong correlations (p < 0.01) between root biomass and MAOM stocks highlight root development as a key driver of SOM stabilization via organo-mineral associations. These findings underscore the role of root-enhancing cover crops in promoting MAOM formation and long-term SOM persistence, offering valuable insights for sustainable soil management.

• Moni, Christophe; Farkas, Eva; Coutris, Claire; Silvennoinen, Hanna Marika; Aas, Anders Bjørnsgaard & Almvik, Marit [Show all 10 contributors for this article] (2025). Interactive Effects of Biochar and Pesticides on Native Soil Organic Matter Mineralisation. European Journal of Soil Science. ISSN 1351-0754. 76(3), p. 1–13. doi: 10.1111/ejss.70137. Full text in Research Archive Show summary

  Biochar and pesticides are likely to be increasingly used in combination in agricultural soils, yet their combined effects on climate change mitigation remain unexplored. This study presents an 8-month incubation experiment with different soil types (silt loam and sandy loam), biochars (corncob and corn stem), and pesticides (with and without a pesticide mixture), during which CO2 production from soil organic matter (SOM) and biochar mineralisation was monitored using isotopic methods. A comprehensive modelling approach, describing all mineralisation results over the entire incubation with a reduced set of parameters, was employed to isolate the effects of biochar, pesticides, and their interactions across soil types and carbon pools, and captured the dynamic effect of biochar on SOM mineralisation. Over 99.5% of biochars remained inert after 8 months, confirming the role of biochar as a carbon sequestration technology. Biochar addition showed higher SOM stabilisation potential in soil with high clay content compared to soil with low clay content. This suggests that biochar amendment should be considered carefully in clay-depleted soils, as it could result in a loss of native SOM. Corn stem biochar, characterised by high surface area and low C/N ratio, demonstrated higher SOM stabilisation potential than corncob biochar with low surface area and high C/N ratio. Pesticide application reduced SOM mineralisation by 10% regardless of soil and biochar types. Finally, the interaction between corncob biochar and pesticides further reduced SOM mineralisation by 5%, while no interactive effect was observed with corn stem biochar. These findings highlight the importance of considering biochar-pesticide interactions when evaluating the impact of biochar amendments on native SOM stability.

• Aas, Anders Bjørnsgard; Andrew, Carrie Joy; Blaalid, Rakel; Vik, Unni; Kauserud, Håvard & Davey, Marie Louise (2019). Fine-scale diversity patterns in belowground microbial communities are consistent across kingdoms. FEMS Microbiology Ecology. ISSN 0168-6496. 95(6), p. 1–11. doi: 10.1093/femsec/fiz058. Full text in Research Archive Show summary

  The belowground environment is heterogeneous and complex at fine spatial scales. Physical structures, biotic components and abiotic conditions create a patchwork mosaic of potential niches for microbes. Questions remain about mechanisms and patterns of community assembly belowground, including: Do fungal and bacterial communities assemble differently? How do microbes reach the roots of host plants? Within a 4 m2 plot in alpine vegetation, high throughput sequencing of the 16S (bacteria) and ITS1 (fungal) ribosomal RNA genes was used to characterise microbial community composition in roots and adjacent soil of a viviparous host plant (Bistorta vivipara). At fine spatial scales, beta-diversity patterns in belowground bacterial and fungal communities were consistent, although compositional change was greater in bacteria than fungi. Spatial structure and distance-decay relationships were also similar for bacteria and fungi, with significant spatial structure detected at <50 cm among root- but not soil-associated microbes. Recruitment of root microbes from the soil community appeared limited at this sampling and sequencing depth. Possible explanations for this include recruitment from low-abundance populations of soil microbes, active recruitment from neighbouring plants and/or vertical transmission of symbionts to new clones, suggesting varied methods of microbial community assembly for viviparous plants. Our results suggest that even at relatively small spatial scales, deterministic processes play a significant role in belowground microbial community structure and assembly.

• Botnen, Synnøve Smebye; Davey, Marie Louise; Aas, Anders Bjørnsgard; Carlsen, Tor; Thoen, Ella & Heegaard, Einar [Show all 12 contributors for this article] (2019). Biogeography of plant root-associated fungal communities in the North Atlantic region mirrors climatic variability. Journal of Biogeography. ISSN 0305-0270. 46(7), p. 1532–1546. doi: 10.1111/jbi.13613. Full text in Research Archive Show summary

  Aim Polar and alpine ecosystems appear to be particularly sensitive to increasing temperatures and the altered precipitation patterns linked to climate change. However, little is currently known about how these environmental drivers may affect edaphic organisms within these ecosystems. In this study, we examined communities of plant root‐associated fungi (RAF) over large biogeographical scales and along climatic gradients in the North Atlantic region in order to gain insights into the potential effects of climate variability on these communities. We also investigated whether selected fungal traits were associated with particular climates. Locations Austria, Scotland, Mainland Norway, Iceland, Jan Mayen and Svalbard. Taxa Root fungi associated with the ectomycorrhizal and herbaceous plant Bistorta vivipara. Methods DNA metabarcoding of the ITS1 region was used to characterize the RAF of 302 whole plant root systems, which were analysed by means of ordination methods and linear modelling. Fungal spore length, width, volume and shape, as well as mycelial exploration type (ET) of ectomycorrhizal (ECM) basidiomycetes were summarized at a community level. Results The RAF communities exhibited strong biogeographical structuring, and both compositional variation as well as fungal species richness correlated with annual temperature and precipitation. In accordance with general island biogeography theory, the least species‐rich RAF communities were found on Jan Mayen, a remote and small island in the North Atlantic Ocean. Fungal spores tended to be more elongated with increasing latitude. We also observed a climate effect on which mycelial ET was dominating among the ectomycorrhizal fungi. Main conclusions Both geographical and environmental variables were important for shaping root‐associated fungal communities at a North Atlantic scale, including the High Arctic. Fungal OTU richness followed general biogeographical patterns and decreased with decreasing size and/or increasing isolation of the host plant population. The probability of possessing more elongated spores increases with latitude, which may be explained by a selection for greater dispersal capacity among more isolated host plant populations in the Arctic.

• Thoen, Ella; Aas, Anders Bjørnsgard; Vik, Unni; Brysting, Anne Krag; Skrede, Inger & Carlsen, Tor [Show all 7 contributors for this article] (2019). A single ectomycorrhizal plant root system includes a diverse and spatially structured fungal community. Mycorrhiza. ISSN 0940-6360. 29(3), p. 167–180. doi: 10.1007/s00572-019-00889-z. Full text in Research Archive Show summary

  Although only a relatively small proportion of plant species form ectomycorrhizae with fungi, it is crucial for growth and survival for a number of widespread woody plant species. Few studies have attempted to investigate the fine scale spatial structure of entire root systems of adult ectomycorrhizal (EcM) plants. Here, we use the herbaceous perennial Bistorta vivipara to map the entire root system of an adult EcM plant and investigate the spatial structure of its root-associated fungi. All EcM root tips were sampled, mapped and identified using a direct PCR approach and Sanger sequencing of the internal transcribed spacer region. A total of 32.1% of all sampled root tips (739 of 2302) were successfully sequenced and clustered into 41 operational taxonomic units (OTUs). We observed a clear spatial structuring of the root-associated fungi within the root system. Clusters of individual OTUs were observed in the younger parts of the root system, consistent with observations of priority effects in previous studies, but were absent from the older parts of the root system. This may suggest a succession and fragmentation of the root-associated fungi even at a very fine scale, where competition likely comes into play at different successional stages within the root system.

• Aas, Anders Bjørnsgard; Davey, Marie Louise & Kauserud, Håvard (2017). ITS all right mama: investigating the formation of chimeric sequences in the ITS2 region by DNA metabarcoding analyses of fungal mock communities of different complexities. Molecular Ecology Resources. ISSN 1755-098X. 17(4), p. 730–741. doi: 10.1111/1755-0998.12622. Full text in Research Archive
• Lorberau, Kelsey; Botnen, Synnøve Smebye; Mundra, Sunil; Aas, Anders Bjørnsgard; Rozema, Jelte & Eidesen, Pernille Bronken [Show all 7 contributors for this article] (2017). Does warming by open-top chambers induce change in the root-associated fungal community of the arctic dwarf shrub Cassiope tetragona (Ericaceae)? Mycorrhiza. ISSN 0940-6360. 27(5), p. 513–524. doi: 10.1007/s00572-017-0767-y. Full text in Research Archive
• Mysterud, Atle; Easterday, William Ryan; Stigum, Vetle Malmer; Aas, Anders Bjørnsgard; Meisingset, Erling L. & Viljugrein, Hildegunn (2016). Contrasting emergence of Lyme disease across ecosystems. Nature Communications. 7. doi: 10.1038/ncomms11882. Full text in Research Archive Show summary

  Global environmental changes are causing Lyme disease to emerge in Europe. The life cycle of Ixodes ricinus, the tick vector of Lyme disease, involves an ontogenetic niche shift, from the larval and nymphal stages utilizing a wide range of hosts, picking up the pathogens causing Lyme disease from small vertebrates, to the adult stage depending on larger (non-transmission) hosts, typically deer. Because of this complexity the role of different host species for emergence of Lyme disease remains controversial. Here, by analysing long-term data on incidence in humans over a broad geographical scale in Norway, we show that both high spatial and temporal deer population density increase Lyme disease incidence. However, the trajectories of deer population sizes play an overall limited role for the recent emergence of the disease. Our study suggests that managing deer populations will have some effect on disease incidence, but that Lyme disease may nevertheless increase as multiple drivers are involved.

• Nilsson, R. Henrik; Hyde, Kevin D.; Pawlowska, Julia; Ryberg, Martin; Tedersoo, Leho & Aas, Anders Bjørnsgard [Show all 59 contributors for this article] (2014). Improving ITS sequence data for identification of plant pathogenic fungi. Fungal diversity. ISSN 1560-2745. 67(1), p. 11–19. doi: 10.1007/s13225-014-0291-8. Full text in Research Archive

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• Inagaki, Thiago Massao; Bøe, Frederik; Sturite, Ievina; Bärmann, Meike S.; Bucka, Franziska & Budai, Alice Erzebet [Show all 8 contributors for this article] (2026). Functional Cover Crop Diversity Enhances Root-Driven Organo-Mineral Associations and Nutrient Efficiency in High-Latitude Agriculture. The 23rd World Congress of Soil Science. doi: https:/www.23wcss.org.cn/. Full text in Research Archive Show summary

  In high-latitude arable systems (63.9°N), short growing seasons and cold climates often constrain regenerative practices. This study investigates how cover crop (CC) diversity influences the synergy among root development, carbon (C) persistence, and nutrient (N and P) dynamics within a barley (Hordeum vulgare L.)-oat (Avena sativa) rotation. Over three years, we evaluated a gradient of CC intercropping complexity using a randomized complete block design. Treatments were: (1) Control (barley/oat without NPK), (2) Biochar-Fertilizer (barley/oat + NPK + 1.8 Mg ha-1 year-1 biochar), (3) Monocrop (barley/oat), (4) Ryegrass (barley + ryegrass), (5) Clover (barley + ryegrass + white/red clover), and (6) Chicory (barley + ryegrass + red clover + chicory + bird’s-foot trefoil). We quantified root biomass, soil organic matter (SOM) fractions, specifically Mineral-Associated Organic Matter (MAOM) and Particulate Organic Matter (POM), aggregate stability, nutrient stocks, and microbial abundance via qPCR. The CCs sown shortly after barley were successfully established, with an average biomass of 1525 kg/ha, without compromising cereal yields, thereby confirming their viability in Nordic climates. A central finding was that root development served as the primary driver of organo-mineral associations. Ryegrass- and Clover-based systems produced significantly higher root biomass, which correlated strongly (p < 0.01) with MAOM stocks and total P acquisition. These systems stored 12 Mg/ha more MAOM-C and 1.1 Mg/ha more MAOM-N than the control at 0-20 cm depth. The inclusion of diverse functional traits in the complex five-species mixture significantly improved soil physical structure, yielding higher aggregate stability and lower bulk density. While CCs accumulated approximately 7 kg P/ha, the diverse mix optimized nutrient availability, whereas simpler mixtures showed higher C:P ratios, suggesting potential microbial P immobilization. Microbial abundance was consistently higher in multi-species treatments, indicating a more active biological environment. Ongoing analysis integrates cereal physiological data, focusing on the photosynthetic efficiency of oats in response to cultivation? regimes. Our findings bridge the gap between root morphology, plant physiology, and long-term SOM persistence, providing a strategic framework for using functional crop traits to enhance soil resilience and nutrient efficiency in cold-climate regions.

• Inagaki, Thiago Massao; Bøe, Frederik; Sturite, Ievina; Bärmann, Meike Sophie; Bucka, Franziska & Budai, Alice Erzebet [Show all 8 contributors for this article] (2026). Root-Mediated Pathways to Mineral-Associated Organic Matter and Soil Health in High-Latitude Cropping Systems. 10th International Symposium on Soil Organic Matter. doi: https:/proceedings.science/som-2026/papers/root-mediated-pathways-to-mineral-associated-organic-matter-and-soil-health-in-h?lang=en. Full text in Research Archive Show summary

  High-latitude regions pose challenges for soil organic matter (SOM) sequestration and for improving soil fertility due to low temperatures, which shorten growing seasons and promote off-season nutrient leaching. Even long-term experiments on conservation practices have shown only modest increases in C storage. Nonetheless, persistent SOM fractions, such as mineral-associated organic matter (MAOM), have been shown to improve relatively quickly through conservation practices in temperate regions, which could be key in high-latitude regions. MAOM is an important SOM fraction not only for promoting carbon (C) storage but also for providing an available form of nitrogen (N) for plant nutrition. In this study, we show that, in Norwegian agriculture (63.9°N), MAOM (C and N) stocks improved only after three years of implementing cover crop systems that combined 1 to 4 cover crops with cereals (barley or oats) intercropped simultaneously (12 Mg ha-1 for C and 1.1 Mg ha-1 for N in the 0-20 cm layer more compared to unfertilized Control plots). Cover crops containing red and white clover and ryegrass efficiently increased the MAOM fraction in soil. An increase in root biomass and changes in root morphology were the primary factors linking cover crops to MAOM improvements in this field. In addition to benefits for SOM stocks, we recorded improvements in microbial abundance, soil structure, nutrient cycling, and cereal physiology. Our findings help to reframe MAOM as a bioavailable nutrient pool essential for soil health and nutrient cycling, which can be improved in the relatively short term through root development.

• Bøe, Frederik; Inagaki, Thiago Massao; Sturite, Ievina & Aas, Anders Bjørnsgaard (2024). Effects of cover crops on soil health properties in Trøndelag: Preliminary results after three years. Full text in Research Archive
• Coutris, Claire; Rivier, Pierre-Adrien; Joner, Erik; Aas, Anders Bjørnsgaard & Solli, Linn (2024). Sources and fate of biodegradable plastics in agricultural soils. Full text in Research Archive Show summary

  Since the 1950s, the use of plastics in agriculture has helped solving many challenges related to food production, while its persistence and mismanagement has led to the plastic pollution we face today. Soils are no exception and concentrations of polyethylene mulch debris up to 380 kg/ha have been reported in Chinese agricultural soils. A variety of biodegradable plastic products have thus been developed and marketed, with the aim to solve plastic pollution through complete degradation after use. But the environmental conditions for rapid and complete degradation are not always fulfilled, and the risk that biodegradable plastics could also contribute to plastic pollution must be evaluated. In this presentation, we want to share the knowledge gained through research projects on biodegradable plastics in agricultural soil, where we both studied the degradation of biodegradable mulch under Nordic soil conditions, and the fate of biodegradable plastics in two major soil amendments: compost and biogas digestate. A two-year field experiment with biodegradable mulch (PBAT-starch and PBAT-PLA) buried in soil in mesh bags showed that also under colder climatic conditions does degradation occur, involving fragmentation already after 2 months, but that complete degradation may take 3 to 9 years, depending on soil temperature and soil organic matter content (both correlate positively with degradation rate). Accumulation is therefore likely to happen when biodegradable mulch is repeatedly used every year. A full-scale experiment with compostable plastic cups (PLA) at an industrial composting plant, where we followed their fate and conducted metagenomic analysis over 13 weeks, demonstrated the major role played by fungi for a successful degradation of PLA. However, the successful management of biodegradable plastic products largely depends on existing waste management infrastructure. Most biodegradable plastic bags, labelled as compostable and used for food waste collection do not end up in industrial composting plants in Norway, but in biogas production plants. Here, we showed that these plastic bags (starch-based polymer) are only marginally degraded (maximum 21-33 % mass loss) during biogas production, and likely to end up in biogas digestate and then in agricultural soils, unless digestate is treated to remove plastic residues.

• Coutris, Claire; Rivier, Pierre-Adrien; Aas, Anders Bjørnsgaard; Solli, Linn & Joner, Erik (2024). Sources and fate of biodegradable plastics in agricultural soils. Full text in Research Archive Show summary

  Since the 1950s, the use of plastics in agriculture has helped solving many challenges related to food production, while its persistence and mismanagement has led to the plastic pollution we face today. Soils are no exception and concentrations of polyethylene mulch debris up to 380 kg/ha have been reported in Chinese agricultural soils. A variety of biodegradable plastic products have thus been developed and marketed, with the aim to solve plastic pollution through complete degradation after use. But the environmental conditions for rapid and complete degradation are not always fulfilled, and the risk that biodegradable plastics could also contribute to plastic pollution must be evaluated. In this presentation, we want to share the knowledge gained through research projects on biodegradable plastics in agricultural soil, where we both studied the degradation of biodegradable mulch under Nordic soil conditions, and the fate of other biodegradable plastics in soil amendments such as compost and biogas digestate. A two-year field experiment with biodegradable mulch (PBAT-starch and PBAT-PLA) buried in soil in mesh bags showed that also under colder climatic conditions does degradation occur, involving fragmentation already after 2 months, but that complete degradation may take 3 to 9 years, depending on soil temperature and soil organic matter content (both correlate positively with degradation rate). Accumulation is therefore likely to happen when biodegradable mulch is repeatedly used every year. A full-scale experiment with compostable plastic cups (PLA) at an industrial composting plant, where we followed their fate and conducted metagenomic analysis over 13 weeks, demonstrated the major role played by fungi for a successful degradation of PLA. However, the successful management of biodegradable plastic products largely depends on existing waste management infrastructure. Most biodegradable plastic bags, labelled as compostable and used for food waste collection do not end up in industrial composting plants in Norway, but in biogas production plants. Here, we showed that these plastic bags (Mater-Bi®) are only marginally degraded (maximum 21-33 % mass loss) during biogas production, and likely to end up in biogas digestate and then in agricultural soils, unless digestate is treated to remove plastic residues.

• Aas, Anders Bjørnsgaard; Rivier, Pierre-Adrien; Joner, Erik; Alvik, Dagny Ugulsvik & Coutris, Claire (2023). Resultater fra storskala forsøk om kompostering av bionedbrytbare ølglass - Hvordan påvirkes det mikrobielle livet i kompost? Full text in Research Archive
• Aas, Anders Bjørnsgaard (2022). The short-term effects of pesticides and biochar amendment on active soil bacteria. Full text in Research Archive
• Wasteson, Yngvild; Sørum, Henning; Lindstedt, Bjørn-Arne; Osinska, Adriana Dorota; Sundsfjord, Arnfinn & Eiken, Hans Geir [Show all 17 contributors for this article] (2021). CORNELIA – Antimicrobial Resistance (AMR) in One Health Interfaces. Full text in Research Archive
• Aas, Anders Bjørnsgard (2013). The role of B. anthracis in the soil microbiome. Full text in Research Archive
• Carlsen, Tor; Aas, Anders Bjørnsgard; Lindner, D; Vrålstad, Trude; Schumacher, Trond & Kauserud, Håvard (2012). Don't make a mista(g)ke: is tag switching an overlooked source of error in amplicon pyrosequencing studies? Fungal ecology. ISSN 1754-5048. 5(6), p. 747–749. doi: 10.1016/j.funeco.2012.06.003. Full text in Research Archive Show summary

  High throughput sequencing has become a powerful tool for fungal ecologists to explore the diversity and composition of fungal communities. However, various biases and errors are associated with the new sequencing techniques that must be handled properly. We here provide evidence for a source of error that has not yet been taken into account. During amplicon pyrosequencing we incorporate tags in both ends of the amplicons, which allows us to check for tag coherence after sequencing. In several studies we have observed that a small proportion of the resulting sequences possess novel tag combinations. Our observations cannot be explained by primer contamination or PCR chimaeras. This indicates that some DNA fragments switch tags during laboratory setup. If not controlled for, this will cause numerous false positives in downstream analyses. In most amplicon pyrosequencing studies of fungal communities, amplicons are typically tagged in one end only. We suggest that amplicons should be tagged in both ends before pyrosequencing to control for tag switching.

• Aas, Anders Bjørnsgard; Carlsen, Tor; Kauserud, Håvard; Mysterud, Atle & Vrålstad, Trude (2010). The effects of animal grazing on species richness and composition of fungal endophytes in a perennial grass. Full text in Research Archive Show summary

  Virtually all land plants host fungal endophytes. However, the composition and diversity of fungal endophytes growing in a range of wild grasses serving as food sources for grazing animals remains largely unexplored. Avenella flexuosa, a perennial grass of the family Poaceae, is abundant in the cold temperate regions of Europe. In alpine habitats of Norway, this grass accounts for ~30% of the diet for about 2.1 million domestic sheep (Ovis aries) that are released for summer grazing yearly. The aim of the present study was to investigate the effect of grazing on the species diversity and composition of endophytes appearing in A. flexuosa in an alpine habitat in Norway. Plants were sampled from plots exposed to grazing (80 sheep per km2) as well as control plots (no grazing). The study area is part of a long-term study measuring the effects of grazing on alpine ecosystems, and has been closely monitored and exposed to controlled grazing pressure for seven years prior to sampling. The presence of fungal endophytes was assessed with traditional culturing methods followed by ITS sequence identification. In parallel, grass bulk samples were screened for total fungal diversity using 454 pyrosequencing. The results of the study will be presented

• Bøe, Frederik; Sturite, Ievina; Holthe, Maren; Inagaki, Thiago Massao; Aas, Anders Bjørnsgaard & Stolte, Jannes (2024). Effekter av direktesåing og fangvekster på jordhelse i Trøndelag og Østlandet - Oppsummering av resultater fra det treårige prosjektet JorNor. NIBIO. ISSN 9788217035541. Full text in Research Archive Show summary

  Jordhelse og metoder for å vurdere hva som er god jordhelse er i stadig utvikling. Ulike sammensetninger av leire, silt og sand, lokale forhold som vær og produksjonsform setter rammene for hva som er god jordhelse et bestemt sted. Det er et behov for å undersøke om direktesåing og bruk av fangvekster er effektive tiltak for å øke jordhelsa. Formålet med JorNor prosjektet var å dokumentere og demonstrere effekter av direktesåing og fangvekster på jordhelse. For å lykkes med direktesåing var det et behov for å kartlegge hvilke såmaskiner som egner seg til dette. Prosjektet ble gjennomført i et samarbeid mellom gårdbrukere fra Østlandet og Trøndelag, rådgivere fra NLR og forskere (NIBIO). Ulike direktesåingsmaskinene ble testet ut. Resultater viser forholdsvis jevn oppspiring og jevnt antall med planter etter de forskjellige behandlingene på høsten. På våren var plantetettheten tilfredsstillende for alle maskinene. Det ble etablert feltforsøk i Midt-Norge og på Østlandet. Gårdsforsøk ble gjennomført i Stadsbygd (Midt-Norge) og i Ås (Østlandet). I Steinkjer ble det undersøkt effekten av ulike blandinger med fangvekster på jordhelseindikatorer. Erfaringer fra gårdsforsøk og ruteforsøk i Trøndelag og på Østlandet viser fordeler ved bruk av fangvekster for noen fysiske, kjemiske og biologiske jordhelseindikatorer. Ruteforsøket på Tuv viste at en kan lykkes med fangvekster også i Trøndelag dersom fangvekstene sås samtidig med eller kort tid etter såing av vårkorn.

• Barcena, Teresa G.; Kolberg, Dorothee; Kok, Nora Hua Ly; Lågbu, Roar; Svendgård-Stokke, Siri & Strand, Geir-Harald [Show all 14 contributors for this article] (2024). Implementering av nasjonalt overvåkingsprogram på jordbruksjord. NIBIO. ISSN 9788217034797. Full text in Research Archive Show summary

  Denne rapporten beskriver alle prosesser som er utarbeidet innenfor datafangst, dataforvaltning, bearbeiding og analyse samt formidling i implementeringsfasen av et nytt jordovervåkingsprogram for jordbruksjord i Norge. Rapporten inneholder detaljerte planer for hvordan jordinformasjon fra ulike indikatorer skal innhentes, analyseres og bearbeides slik at tilstand og endring i jordsmonnet kan overvåkes. Programmet vil danne grunnlaget for landsdekkende jordinformasjon som muliggjør en vurdering av jordsmonnets status og endring for de fem truslene man har identifisert for norsk jordbruksjord: erosjon, jordpakking, tap av organisk materiale, tap av jordbiodiversitet og forurensning.

• Aas, Anders Bjørnsgaard; Davey, Marie Louise; Kauserud, Håvard; Easterday, William Ryan & Brysting, Anne Krag (2017). Root-associated microbes: Spatial Oddities and Methodological Perspectives. Universitetet i Oslo. Full text in Research Archive
• Aas, Anders Bjørnsgard; Vrålstad, Trude; Carlsen, Tor; Kauserud, Håvard & Mysterud, Atle (2010). Diversity and species composition of fungal endophytes in Avenella flexuosa under different sheep grazing regimes. Universitetet i Oslo. Full text in Research Archive Show summary

  Fungal endophytes have been shown to be extremely widespread and abundant in terrestrial plants. It is also known that fungal endophytes may affect the grazing intensity of the host plant. In this study the occurrence of fungal endophytes in the perennial grass Avenella flexuosa was investigated under different grazing regimes in a field site in Norway. The main aim was to reveal to what degree the grazing influenced the fungal diversity and species composition. The fungal endophytes were analyzed using both culturing coupled to Sanger sequencing as well as 454 sequencing. The ITS2 rDNA region was used as a fungal DNA barcode. Based on the 454 data, a higher number of fungi were detected in stems of grazed compared to non-grazed plants. However, no significant difference was observed in the inflorescences and leaves. A distinct difference in fungal community composition was observed between leaves, stems and inflorescences. Apparently, the fungal community composition varied more in non-grazed compared to grazed plants. Saturation curve analyses indicated that most fungi remained undetected. Noteworthy, a high discrepancy was observed between the two methods, both in OTU number and overlap. From the 37 and 896 operational taxonomic units obtained from cultivation and 454 sequencing respectively. Only three OTUs were recovered by both methods. No known toxin producing endophytes were detected in A. flexuosa. Instead, Phaeosphaeria/Stagonospora spp. dominated both culture and 454 data, constituting potentially biological important endophytes of this grass. Intriguingly, various basidio-yeasts with high prevalence in the 454 dataset were not recovered by cultivation. This study indicates that grazing may have some influence on the diversity and composition of fungal endophytes. However, the different approaches underlines that the results must be interpreted with great care since there are many potential biases inherent both with the culturing and the 454 sequencing approach.

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