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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.

2023

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Abstract

Questions During the winter of 2014, an intense drought combined with sub-zero temperatures resulted in a massive Calluna dieback in Norwegian heathlands. We studied the initial vegetation recovery under two management approaches: natural recovery and prescribed burning. We hypothesized that natural recovery will be slower in more drought-affected sites, whereas burning will facilitate post-fire recovery in all sites by effectively removing dead and damaged heath. Both natural recovery and post-fire succession will be slower in the north. Location Calluna heath in seven sites spanning an approx. 600-km latitudinal gradient along the coast of Norway (60.22–65.69° N). Methods After a natural drought, 10 permanent plots per site were either burnt or left for natural recovery. Vegetation data were recorded annually in 2016 (pre-fire) and 2017–2019 (post-fire) reflecting a factorial repeated-measures design (n = 280). The data were analyzed using mixed-effects models. Results Two years after the drought, we observed high but variable Calluna damage and mortality. Over the four years of study, damaged Calluna recovered, whereas dead Calluna showed little recovery. Both the extent of the damage and mortality, as well as the rate of natural recovery, are only weakly related to site climate or environmental factors. Fire efficiently removed dead and damaged Calluna and facilitated post-fire successional dynamics and recovery in a majority of sites. Conclusions Extreme winter drought resulted in substantial and often persistent damage and dieback on Calluna along the latitudinal gradient. In sites with high mortality, prescribed burning removed the dead biomass and, in some cases, facilitated vegetation recovery. Traditional heathland management, which uses burning to facilitate all-year grazing by Old Norse sheep in Atlantic coastal heathlands, can be an efficient tool to mitigate dieback events and more generally to increase resistance to and resilience after extreme drought events in the future.

Abstract

The aim of the article is to assess whether agricultural landscapes play a role in the perception of Norway held by tourists and residents. An additional aim is to analyse whether information accompanying images on social media indicate that the photographers have acknowledged the agricultural landscape. The authors used geotagged images uploaded to the image-sharing platform Flickr in their analyses. They selected photos from within the agricultural landscapes, inspected them, and categorized them according to extent and content. Additionally, they analysed the accompanying hashtags. The findings revealed that a large proportion of the photos contained agricultural landscapes, and thus confirmed the importance of the agricultural landscape for visual perception of and access to Norwegian landscapes. In addition, the lack of agricultural-related hashtags strengthened the authors’ suspicions that this might not have been widely recognized by the photographers. Thus, while agricultural landscapes commonly are considered primarily as landscapes of food production, the authors conclude that these landscapes also fulfil other functions and that their contribution to the perception of Norway is important. Additionally, many of the landscape elements seen and analysed in the sample of photos are elements that play a role in providing cultural ecosystem services.

Abstract

Carrot is the main field vegetable in Norway and is stored at 0-1°C for up to 8 months. In long-stored carrots, postharvest diseases are problematic. Better knowledge of the causal agents of postharvest diseases can help producers apply appropriate control measures to reduce carrot loss and waste. The objectives of this study were to determine the extent of the tip rot problem and the prevalence of other storage diseases of carrots in different regions in Norway. The study was conducted from 2019 to 2021 by collecting carrots from 16 commercial cold storages, representing four regions. From each storage, representative carrots were randomly sampled, washed, and sorted into different disease categories and healthy carrots. Representative samples from each category were further analyzed in the NIBIO laboratory to identify the causal agent(s) and confirm the disease. Causal agent(s) were identified by symptom and sign description, microscopy and when necessary, DNA sequencing. One or more pathogens were identified from each symptomatic carrot. The incidence of postharvest diseases significantly varied among regions. Taking all years and regions together, only 42% of the carrots were healthy. In other words, 58% of the carrots were with one or more diseases, representing a waste due to diseases alone. Tip rot alone contributed to about 30% of the postharvest loss. Our results indicate that the burden of postharvest diseases of carrots is increasing. This includes diseases like tip rot disease complex, Cylindrocarpon root rot and cavity spot. The results are useful to direct research investigation of the most problematic diseases. Most of the post-harvest diseases of carrots are the result of latent infections that occur in the field, and stress during handling, storage, and processing operations. Hence, postharvest disease control measures should consider the pre-and postharvest predisposing factors of carrots for storage rot.