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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.

2025

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Abstract

Key messages: Multifunctionality should serve as a guiding principle for forest governance and investment, complementing production and conservation objectives. To operationalise this vision, three guiding principles should inform EU and national policies: • Plan and manage at the landscape level balancing production, biodiversity, climate adaptation and social needs in complementary ways. Policies should support a diversity of management practices. • Align sectoral policies to ensure coherence between forestry, energy, biodiversity, climate and social objectives. • Reward and support multifunctionality explicitly through advisory programmes, certification systems, and financial mechanisms that recognise and support diverse management practices.

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Abstract

One of the key challenges we face today is the changing climate and its environmental impacts, affecting all life on Earth. Examining historical human responses to climate crises provides insights into resilience and adaptability. Robust data is essential for studying past climate and environmental changes effectively. European climate records covering the past 2000 years reveal a prolonged cooling period, known as the Dark Ages Cooling Period (c. 300–800 CE), punctuated by a pronounced cooling in the mid-6th century. Studies show that these cold intervals are more complex and regionally varied than previously believed. In the 6th century in Norway, archaeological evidence points to crop failures, famine, farm abandonment and changes in social organization in some regions, while others experienced minimal impact during these cold periods. However, southeastern Norway lacks detailed high-resolution paleoclimate and paleoenvironmental reconstructions, limiting our ability to fully understand these events. This thesis aims to enhance understanding of climate, environmental, and societal dynamics in southeastern Norway over the past 2000 years, focusing on the Dark Ages Cold Period (c. 300–800 CE), through sediment analysis from Lake Sagtjernet and Lake Ljøgottjern in southeastern Norway. We introduce a μCT scan method for varve counting for Lake Sagtjernet, establishing the first varve chronology from a Norwegian lake, covering c. 4023 years. This chronology enables the first paleoclimate and paleoenvironmental reconstruction from Norwegian varved lake sediments. This reconstruction reveals 2000 years of temperature variability, highlighting a major cooling event—the largest in 2000 years—that aligns with the 6th century cooling event. However, sparse settlements in the first millennium complicate climate impact interpretation at Lake Sagtjernet, while the last millennium shows increased human activities during both warm and cold periods. Reconstructed temperatures between 200 and 1300 CE from Lake Ljøgottjern indicate a notably colder period from 300 to 800 CE, compared to the periods before (200–300 CE) and after (800–1300 CE), identified as the Dark Ages Cold Period. Temperature fluctuations within this cold period significantly influenced agricultural strategies at the more populated Lake Ljøgottjern. Warmer intervals favoring crop cultivation and colder intervals prompting a shift towards livestock farming, illustrating the impact of climatic conditions on societal development.

Abstract

Abstract Ice encasement (IE) is one of the big challenges in winter stress management on golf course putting greens in Northern Scandinavia. The turfgrass is damaged due to lack of oxygen (hypoxia or anoxia) and accumulation of toxic by‐products of anaerobic respiration. Breeding IE‐tolerant turfgrass species and varieties is the best defense against these challenges. A method to simulate ice encasement was tested to screen selected varieties of winter‐hardy bentgrass species and red fescue subspecies. Note that 32 varieties were chosen from the SCANGREEN trial seeded at NIBIO Landvik, Norway, in 2019. Samples were taken in December 2020, 2021, and 2022, vacuum sealed in plastic, and stored in darkness at 0.5°C for up to 77 days to test them for their tolerance to simulated ice encasement (SIE). Samples were incubated at different intervals; plants were potted, and tiller survival was tested after 4 weeks of regrowth. Lethal duration of ice encasement (LD 50 ) that is, the number of days under anoxia that kills 50% of the plant population for each species and variety was calculated. The results showed that the ranking of cool season turfgrass species for tolerance to SIE was velvet bentgrass > Chewings fescue > slender creeping red fescue = colonial bentgrass > creeping bentgrass. This ranking does not fully reflect the ranking found in field tests where velvet bentgrass was superior together with creeping bentgrass. SIE caused a more rapid development of anoxia than IE in the field, and we hypothesize that creeping bentgrass is less tolerant to these conditions compared to the other species tested. To make the SIE method more representative for IE in field, it should be further adapted with incubation at lower temperatures, and with acclimation conditions to be standardized prior to sampling. Within species, the best tolerance to IE was found in velvet bentgrass Nordlys, creeping bentgrass Penncross, Chewings fescue Lykke, and slender creeping red fescue Cezanne.

Abstract

Abstract The primary benefits of turfgrass sod include rapid greenery and soil coverage, but its production causes concerns about soil losses at production sites. Soil adheres to the grass root system during harvesting and is removed from the sod farm, which in the long run might lead to soil degradation on the sod farm. In this study, we investigated sod thickness and the removal of organic and mineral matter when harvesting 24 fields representing 12 Norwegian sod farms in 2022 and 2023. On each field, 10 sod strips were randomly chosen, and five sod plugs were collected from each strip. Sod thickness was measured using a sliding gauge. Sod mineral matter (SMM: soil and thatch mineral matter) and sod organic matter (SOM: soil and thatch organic matter) contents were quantified by loss on ignition at 550°C. Management and field properties were also documented. Results showed an average amount of mineral matter in the sod strips of 36 Mg ha −1 for all fields but with significant variation among fields ( p  < 0.001). The average SOM content was 10 Mg ha −1 . Mean sod thickness was 15.4 mm and had a strong correlation with SOM ( r  = 0.8) but only a moderate correlation with SMM ( r  = 0.6). Soil water content and surface hardness at harvest affected sod thickness and SMM only slightly. Sod harvesters with twin heads harvested significantly thicker sod strips and removed more mineral matter than harvesters with single cutting heads. Soil texture did not have a significant impact on sod thickness or mineral matter removal.

Abstract

The study focuses on ecosystem services, historical aspects, and natural diversity. Specifically, it assesses possible proxies for investigating a set of cultural ecosystem services from the Norwegian agricultural landscape. Agricultural areas on the Norwegian land cover map surrounded by a 100  m wide buffer zone were analyzed for recorded historical buildings, cultural heritage sites, red-listed vascular plant species (defined as being at varying degrees at risk of extinction), and red-listed nature types (defined as endangered or vulnerable). The results indicate significant contributions from agricultural landscapes with respect to historical buildings, cultural heritage sites, and red-listed plant species. Regarding red-listed nature types, the contributions were diverse. The ecosystem proxies investigated showed increasing distribution trends with increasing proportions of agricultural landscapes in the spatial units, with a sharp increase with smaller area sizes. However, for cultural heritage sites the trend was different when the proportion of the agricultural landscape was below 25%; it showed a very slow increase. In conclusion, the study highlights the agricultural landscape’s diverse contributions to the investigated ecosystem services in Norway, prompting the need for further research on additional ecosystem services to ensure the continued delivery of environmental and social well-being.

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Abstract

To achieve a circular bioeconomy, nutrients within residues such as food waste (FW) and sewage sludge (SS) must be recycled to e.g., food production. However, these biowastes often contain numerous contaminants which are recycled alongside the nutrients. Identifying these contaminants is crucial to prevent potential harmful effects when residues from circular processes, including biogas digestates, are utilized as fertilizers or soil amendments in agriculture. In this study, suspect and nontarget screening was used to comprehensively assess contaminants of emerging concern (CECs) and their transformation products (TPs) in biogas digestates derived from FW and SS. A total of 133 CECs and five TPs were tentatively identified, including 61 pharmaceuticals and personal care products (PPCPs), eight pesticides, and 64 industrial chemicals, with 44 of these CECs confirmed using analytical standards. Concentrations ranged from low μg kg−1 dry matter (DM) to several hundred mg kg−1 DM. SS based digestates were found to be more heavily contaminated with industrial chemicals and PPCPs, while FW based digestates contained higher levels of pesticides. These findings highlight the importance of stringent contaminant surveillance to ensure the safe agricultural application of biogas digestates and to mitigate potential risks associated with the recycling of organic residues.

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Abstract

Abstract It is essential to reduce pesticide and tillage use in agricultural systems, but better alternatives for controlling perennial weeds are needed. The horizontal and vertical root cutters can fragment the roots and rhizomes of perennial weeds with minimal disturbance to the soil and vegetation cover. However, there is a lack of studies on how the root cutters affect multiple perennial weed species, and their effect on soil and nutrient losses. To fill this gap, three multi-year experiments in plowed systems were conducted in Norway and Sweden to study whether the roots cutters can control multiple perennial weed species as effectively as more intensive tillage methods (Experiments 1-2), without increasing soil and nutrient losses (Experiment 3). Overall, the more intensive tillage methods tested (rotary tiller, disc harrow, stubble harrow) did not provide significantly better perennial weed control than the horizontal root cutter. In Experiment 1, the horizontal root cutter reduced Sonchus arvensis and Elymus repens shoot biomass by 52% and 80%, respectively, compared to an untreated control. In Experiment 2, the horizontal root cutter reduced Cirsium arvense shoot numbers by 71% compared to the untreated control but failed to reduce E. repens . Horizontal root cutter treatment depth (7 vs. 15 cm) did not affect control efficacy. The horizontal root cutter treatment did not increase soil, water or nutrient losses compared to the untreated control, and resulted in 60% less soil and 52% less phosphorous losses than disc harrowing. Treatments with the vertical root cutter had 40% less E. repens and 22% less S. arvensis shoot biomass than treatments without the vertical root cutter. This manuscript is the first to show the true potential of the root cutters in plowed systems in northern Europe and their ability to control of multiple perennial weed species with low risk of soil and nutrient losses.

Abstract

Background: Giant hogweed (Heracleum mantegazzianum Sommier and Levier) is a perennial herbaceous plant that can grow to a height of 2-5 m. A single flowering plant can produce more than 20,000 seeds. It is one of Europe’s most widespread and problematic invasive alien species and a severe threat to native biodiversity. Glyphosate is widely used to control H. mantegazzianum. Decades of intensive herbicide spraying have led to environmental pollution, prompting a need to explore new methods to supplement or replace glyphosate. Objective: Non-chemical methods to control H. mantegazzianum were tested and compared with glyphosate application. Methods: In two infested locations in southeast Norway, we compared the efficacy of glyphosate applications with a combination of mechanical cutting of the flowering stem of H. mantegazzianum and hot water treatment (80 °C). Hot water or glyphosate was supplied by foliar application or injection into the root crown. Results: The best method to reduce cover and the number of H. mantegazzianum rosettes and seedlings was achieved with two foliar applications of glyphosate. Cutting the flowering stem and injecting hot water into the root crown was almost as efficient as glyphosate application. Cutting and foliar applications of hot water had the weakest efficacy. Despite the best control and significant growth of grasses after glyphosate treatment, relatively high percentage of bare soil remained in the plots afterwards, increasing the risk of erosion. Conclusions: Cutting and injection of hot water in the root crown may be a viable alternative to glyphosate application in areas where herbicides are undesirable.