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.
2024
Abstract
No abstract has been registered
Abstract
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.
Abstract
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.
Authors
Cornelya Klutsch Junbin Zhao Mikhail Mastepanov Hanna Marika Silvennoinen Juho Vuolteenaho Erling Fjelldal David Kniha Runar Kjær Snorre HagenAbstract
No abstract has been registered
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No abstract has been registered
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No abstract has been registered
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No abstract has been registered
Abstract
Aim Effective management of non-indigenous species requires knowledge of their dispersal factors and founder events. We aim to identify the main environmental drivers favouring dispersal events along the invasion gradient and to characterize the spatial patterns of genetic diversity in feral populations of the non-native pink salmon within its epicentre of invasion in Norway. Location Mainland Norway and North Atlantic Basin. Methods We first conducted SDM using four modelling techniques with varying levels of complexity, which encompassed both regression-based and tree-based machine-learning algorithms, using climatic data from the present to 2050. Then, we used the triple-enzyme restriction-site associated DNA sequencing (3RADseq) approach to genotype over 30,000 high-quality single-nucleotide polymorphisms to elucidate the patterns of genetic diversity and gene flow within the pink salmon putative invasion hotspot. Results We discovered temperature- and precipitation-related variables drove pink salmon distributional shifts across its non-native ranges and that climate-induced favourable areas will remain stable for the next 30 years. In addition, all SDMs identified north-eastern Norway as the epicentre of the pink salmon invasion, and genomic data revealed that there was minimal variation in genetic diversity across the sampled populations at a genome-wide level in this region. While utilizing a specific group of ‘diagnostic’ SNPs, we observed a significant degree of genetic differentiation, ranging from moderate to substantial, and detected four hierarchical genetic clusters concordant with geography. Main Conclusions Our findings suggest that fluctuations in climate extreme events associated with ongoing climate change will likely maintain environmental favourability for the pink salmon outside its ‘native’/introduced ranges. Locally invaded rivers are themselves potential source populations of invaders in the ongoing secondary spread of pink salmon in Northern Norway. Our study shows that SDMs and genomic data can reveal species distribution determinants and provide indicators to aid in post-control measures and potentially inferences about their success.
Authors
Junbin Zhao Mikhail Mastepanov Carla Stadler Cornelya Klutsch Erling Fjelldal David Kniha Runar KjærAbstract
No abstract has been registered