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
Forfattere
Kristian Hansen Matthias Koesling Håvard Steinshamn Bjørn Gunnar Hansen Tommy Dalgaard Sissel HansenSammendrag
In this study, 200 Norwegian dairy farms were analyzed over three years to compare greenhouse gas emissions, nitrogen (N) intensity, gross margin, and land use occupation between organically and conventionally managed farms. Conventionally managed farm groups were constructed based on propensity matching, selecting the closest counterparts to organically managed farms (n=15). These groups, each containing 15 farms, were differentiated by an increasing number of matching variables. The first group was matched based on geographical location, milk quota, and milking cow units. In the second match, the proportion of milking cows in the total cattle herd was added, and in the third, the ratio of milk delivered to milk produced and concentrate usage per dairy cow were included. The analysis showed that the conventionally managed farms (n=185) had higher greenhouse gas emissions (1.42 vs 0.98 kg CO2 per 2.78 MJ of edible energy from milk and meat, calculated as GWP100-AR4) and higher N intensity (6.9 vs 5.0 kg N input per kg N output) compared to the organic farms (N=15). When comparing emissions per kg of energy-corrected milk (ECM) delivered, conventional farms also emitted more CO2 (1.07 vs 0.8 kg CO2 per kg ECM). Furthermore, conventionally managed farms showed lower gross margins both in terms of NOK per 2.78 MJ edible energy delivered (5.8 vs 6.5 NOK) and per milking cow unit (30 100 vs 34 400 NOK), and they used less land (2.9 vs 3.6 m² per 2.78 MJ edible energy delivered) compared to organic farms. No differences were observed among the three conventionally managed groups in terms of emissions, N intensity, land use occupation, and gross margin.
Forfattere
Kristian Hansen Håvard Steinshamn Matthias Koesling Tommy Dalgaard Bjørn Gunnar Hansen Sissel HansenSammendrag
Dairy farming yields milk and meat; however, production is linked with an environmental burden (Wattiaux et al., 2019). In our study N-intensity, GHG emission and land use occupation at 200 dairy farms from central Norway was calculated from cradle to farm gate. Nitrogen intensity was calculated as sum of N from purchased inputs, biological N-fixation, atmospheric N-deposition, N-surplus from off-farm production of ingredients for concentrates and roughage and of bought animals divided by N in delivered milk and meat (Koesling et al., 2017). The organic farms (n=15) had a lower N-intensity than conventional managed farms (n=185) (5.0 vs 6.9 kg N/kg N). Mainly explained by lower use of imported N in the organic farm group. The organic managed farms, however, had a higher land use occupation than conventional farms (3.6 vs 2.9 m2 per 2.78 MJ edible energy in milk or meat delivered (2.78 MJMM)). The GHG emissions per 2.78 MJ edible energy in milk or meat was on average 1.4 kg CO2/2.78 MJMM edible energy for all farms (n=200). The GHG emission was correlated with N-intensity (r2=0.85), which indicate that reduced N-intensity is associated with lower GHG emissions per product unit. Our results support that improved utilization of local resources, e.g. manure, legumes in grass- based forage are likely to reduce N-intensity at both organic and conventional managed farms. Reduced N-intensity will likely lessen GHG emissions. The reduced N-intensity and GHG emission came at an expense of increased land use occupation per produced product. References Koesling, M., Hansen, S., Bleken, M.A., 2017. Variations in nitrogen utilisation on conventional and organic dairy farms in Norway. Agric Syst. 157, 11–21. https://doi.org/10.1016/j.agsy.2017.06.001. Wattiaux, M.A., Uddin, M.E., Letelier, P., Jackson, R.D., Larson, R.A., 2019. INVITED REVIEW: Emission and mitigation of greenhouse gases from dairy farms: The cow, the manure, and the field. AAS. 35 (2), 238-254. https://doi.org/10.15232/aas.2018-01803.
Forfattere
Mette Thomsen Randi Seljåsen Reidun Pommeresche Till Seehusen Belachew Asalf Tadesse Tatiana Francischinelli Rittl Anne-Kristin LøesSammendrag
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Sammendrag
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Sammendrag
1. We propose that the ecological resilience of communities to permanent changes of the environment can be based on how variation in the overall abundance of individuals affects the number of species. Community sensitivity is defined as the ratio between the rate of change in the log expected number of species and the rate of change in the log expected number of individuals in the community. High community sensitivity means that small changes in the total abundance strongly impact the number of species. Community resistance is the proportional reduction in expected number of individuals that the community can sustain before expecting to lose one species. A small value of community resistance means that the community can only endure a small reduction in abundance before it is expected to lose one species. 2. Based on long-term studies of four bird communities in European deciduous forests at different latitudes large differences were found in the resilience to environmental perturbations. Estimating the variance components of the species abundance distribution revealed how different processes contributed to the community sensitivity and resistance. Species heterogeneity in the population dynamics was the largest component, but its proportion varied among communities. Species-specific response to environmental fluctuations was the second major component of the variation in abundance. 3. Estimates of community sensitivity and resistance based on data only from a single year were in general larger than those based on estimates from longer time series. Thus, our approach can provide rapid and conservative assessment of the resilience of communities to environmental changes also including only short-term data. 4. This study shows that a general ecological mechanism, caused by increased strength of density dependence due to reduction in resource availability, can provide an intuitive measure of community resilience to environmental variation. Our analyses also illustrate the importance of including specific assumptions about how different processes affect community dynamics. For example, if stochastic fluctuations in the environment affect all species in a similar way, the sensitivity and resistance of the community to environmental changes will be different from communities in which all species show independent responses.
Forfattere
Emily FollettSammendrag
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Forfattere
Emily FollettSammendrag
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Forfattere
Emily FollettSammendrag
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Sammendrag
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Forfattere
Sarah MuiruriSammendrag
Entomophagy, the consumption of insects, may reduce the negative health and environmental impacts of meat. As one of the novel protein alternatives expected to replace conventional meat consumption, its success will depend on consumer acceptance. To investigate the consumer acceptance of entomophagy, three rounds of a Norwegian survey with 8633 useable responses conducted in 2019/2020, 2021/2022, and 2023/2024 were used. Generalized structural equation modelling was used to test the developed hypotheses. The direct effects of trust, food choice motives, and OCEAN personality traits were investigated. The mediating effects of food safety concerns on the relationship between trust and willingness to try (WTT) food made from insects were also investigated. Social trust and trust in food authorities were positively associated with WTT. No association was found for trust in retailers. Negative associations were found between the effects of social trust and trust in food authorities on food safety concerns, and food safety concern was also a significant mediator. Respondents who emphasized environmental friendliness, health, and novelty were more willing to try, and those who emphasized natural ingredients and familiarity were less willing. Openness was positively associated with WTT, while conscientiousness, extraversion, and agreeableness had a negative association. Gender, education, age and urban living were also found as significant moderators in some paths. The findings of the study imply the need to foster trust among consumers and to emphasize the environmental and health benefits of entomophagy while focusing on increasing consumer familiarity and use of natural ingredients. Personality-focused marketing strategies may also be implored to target consumers high in openness and low in conscientiousness, extraversion, and agreeableness.