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.
2021
Authors
Anders Nielsen Inger Elisabeth Måren Line Rosef Lawrence Richard Kirkendall Martin Malmstrøm Hugo de Boer Katrine Eldegard Kjetil Hindar Lars Robert Hole Johanna Järnegren Kyrre Linné Kausrud Erlend Birkeland Nilsen Eli Knispel Rueness Eva Bonsak Thorstad Gaute VelleAbstract
We sow or plant vascular plant species on a large scale in revegetation and restoration projects in Norway today. Some of the species used are already found in Norway, but many of the species, subspecies or populations used though native are not local, that is, they are regionally alien. A regionally alien species is a species that is native to Norway (has been in Norway since 1800) somewhere in the country, but which has been spread by humans to places in Norway where they do not occur. In theory, and according to the Biodiversity Act, it is desirable to use local seeds or plants to preserve local biodiversity. The aim of this report is to define guidelines that helps prevent the planting of vascular plant species with a high potential for negative effects on local biodiversity. It is assumed that the native or local populations are better adapted to local environmental conditions than populations from other areas or regions, and the risk of harmful genetic changes is therefore considered small when using local plant and seed sources. Arriving at a common definition for the area within which plants are “local” is difficult, though; vascular plant species are numerous (3317 species in mainland Norway, of which more than half are alien species introduced after 1800, Artdatabanken 2015), have different growth forms, different environmental requirements, and different reproductive and dispersal ecology. Even closely related vascular plant species can differ in such characteristics and hence in the extent of the "place" or “area”. The dispersal ecology of a plant species is of great importance for whether the species has genetically distinct populations within its range or not. Different strategies (wind pollination vs. insect pollination, vegetative propagation vs. seed dispersal, large seeds vs. small seeds) have an impact on the degree of gene flow between populations and thus also how locally adapted the species is in different areas. Whether the species has primarily vegetative reproduction or whether it spreads mainly by means of seeds, and whether the seed dispersal takes place ballistically, with wind or water, or by zookori (attached to animals or eaten by animals) determines how far the species can spread and how large gene flow there is between different populations. Whether the species is pollinated by wind or by the help of insects also affects the degree of gene flow differently. In Norway, there is great variation in many biophysical and ecological conditions (climate, topography, hydrology, and geology) over relatively short distances. This means that species that grow only a few meters apart can grow under different environmental conditions. This large variation in environmental conditions - on different spatial scales - can give rise to local genetic adaptation. However, plants have been moved around the landscape for several hundred years by our livestock (as seeds in fur and hooves, and in faeces) from lowland pasture to mountain pasture and along traffic arteries across the country due to the extensive transport of animals and people. Over time, this has led to expanded geographical distribution for several species and increased gene flow between populations over relatively large distances. .............
Authors
Eva Bonsak Thorstad Åse Helen Garseth Tor Gjøen Snorre Gulla Håvard Lo Martin Malmstrøm Tor Atle Mo Gaute Velle Hugo de Boer Katrine Eldegard Kjetil Hindar Lars Robert Hole Johanna Järnegren Kyrre Kausrud Lawrence R. Kirkendall Inger Elisabeth Måren Erlend Birkeland Nilsen Rolf Erik Olsen Espen Rimstad Eli Knispel Rueness Øyvind Øverli Anders NielsenAbstract
Introduction Atlantic salmon in the River Klarälven in Sweden live the entire life in freshwater, undertaking feeding migrations to Lake Vänern. The upper part of the watershed is in Norway and comprises the River Trysilelva and associated rivers and lakes. Atlantic salmon previously lived in the Norwegian part of the watershed but were lost due to the construction of 11 hydropower stations that block the upstream migration from Vänern. The power stations also cause a high mortality among downstream migrating fish. Tagging studies showed that there is 71-84% mortality of juveniles (smolts) and 100% mortality of adults during downstream migration past the eight lowermost power stations. Extensive mitigation measures are needed to reduce the mortality of downstream migrants and reestablish a population that can reach areas in Norway naturally without being captured in Sweden and transported to Norway. In 2015, the total costs of establishing fishways bypassing the power stations and securing safe downstream migration was estimated to be 1000 million SEK. To compensate for a decline of salmon due to lost habitat, hatchery-produced juveniles have been released in the watershed for more than 100 years, and adult salmon have been captured in the lower reaches of Klarälven and released in upstream reaches. After the Höljes power station was built, 80% of the salmon transported upstream were released upstream of Höljes. In 1993, the Norwegian government stopped these releases due to the large mortality of downstream migrating fish at the power stations. The releases had already been stopped from late summer 1988 due to bacterial kidney disease (BKD) outbreaks in salmon populations in the watershed. Since 1988, transported fish have been released upstream of Edsforsen in Sweden, and have not been able to reach Norway. Aim of report The Norwegian Environment Agency asked VKM to carry out a risk assessment of three specified methods that can be used to reestablish salmon in the Norwegian part of the watershed. This risk assessment is pertinent because the occurrence of alien organisms and infectious agents have developed differently in the Swedish and Norwegian parts of the watershed after salmon became unable to migrate through the river system. In 2013, the fish parasite Gyrodactylus salaris was detected in Klarälven, but has not been recorded in Norwegian parts of the watershed. Here, we assess the risk of negative impacts on native biodiversity by importing Atlantic salmon eggs or live adults from Klarälven to Norway. Three methods of importing eggs or adults were assessed: I. Import of fertilised eggs to a local hatchery in Norway, which are planted in the river in the spring or hatched and released as juveniles or smolts. II. Import of fertilised eggs that will be used to establish a long-term broodstock in Norway using the gene bank model, from which eggs can be planted into the river, or transferred to a local hatchery with subsequent release of juveniles or smolts. III. Import of adult salmon spawners that are captured in the lower parts of Klarälven in Sweden, transported in tanks and released in the Norwegian parts of the watershed. Methods The risk assessment was based on a literature review and qualitative assessment of each of the three methods of importing eggs or adults. The risk of impacts on native biodiversity and ecosystems was assessed for infectious agents, including parasites, bacterial pathogens, and viruses, and for other alien species. For each of the infectious agents and alien species, the risk is based on the product of the magnitude of the potential negative impact to native biodiversity and ecosystems, and the likelihood that negative consequences occur. The risk assessment concludes in terms of low, moderate, or high risk. .......................
Authors
Gaute Velle Lennart Edsman Charlotte Evangelista Stein Ivar Johnsen Martin Malmstrøm Trude Vrålstad Hugo de Boer Katrine Eldegard Kjetil Hindar Lars Robert Hole Johanna Järnegren Kyrre Linné Kausrud Inger Elisabeth Måren Erlend Birkeland Nilsen Eli Knispel Rueness Eva Bonsak Thorstad Anders NielsenAbstract
Key words: Risk assessment, Crayfish, Shrimps, Crabs, Climate change, Aphanomyces astaci, White spot syndrome, Alien species, Biological invasion Introduction The Norwegian Scientific Committee for Food and Environment (VKM) was requested by the Norwegian Environment Agency to assess the risk of negative impacts to biodiversity in Norway resulting from import of crustacean decapods for keeping in freshwater aquariums. VKM was asked to 1) list species of crayfish, crabs and shrimps that are currently kept in freshwater aquaria in Norway, and species that are likely to be kept in freshwater aquaria in Norway within the next 10 years, 2) assess the ability of the species to survive under Norwegian conditions and cause impacts on ecosystems and other species, and 3) state the potential negative effects on the biological diversity of diseases caused by pathogens, regulated under the Norwegian Food Act. Methods The risk assessment, without focus on pathogens, was performed in two steps. First, we used a pre-screening toolkit to identify species of crayfish, crabs and shrimps with potential to become invasive in freshwater habitats in Norway. Each species was given an invasiveness score based on 55 questions on biogeography, ecology, and climate change. In a second step, a full risk assessment, including the potential impacts of pathogens, was conducted on those species receiving the highest invasiveness score. This assessment included questions on the organism’s probability of entry and pathways of entry, establishment and spread, potential impacts on biodiversity, and how climate change scenarios might affect the assessment. Likelyhood and confidence was assessed for each question. In conclusion, each species was designated as either low-, moderate-, or high risk. Many crustacean decapod species are confirmed or suspected carriers of pathogens that can cause mass mortality among native crustaceans. The risk posed by crustaceans as carriers of pathogens may be independent of the environmental risk that they pose through ecological interactions. Therefore, the four crustacean disease pathogens that are regulated under the Norwegian Food Act, were assessed separately. These include Aphanomyces astaci causing crayfish plague, white spot syndrome virus (WSSV) causing white spot disease, Taura syndrome virus (TSV) causing Taura syndrome, and yellow head virus genotype 1 (YHV1) causing yellow head disease. The assessments comprised questions on the pathogen’s probability of entry (as a hitchhiker organism with imported crustaceans), pathways of entry, establishment and spread, and potential impact on crustacean biodiversity. Likelihood and confidence were assessed for each question. In conclusion, each pathogen was designated as either low-, moderate-, or high risk. In a third step, we categorized the likelihood that a crustacean species introduces a pathogen associated with a high- or moderate risk into: I) known chronic carriers, II) suspected chronic carriers, III) suspected situational carrier, IV) possible pathogen transmitters, and V) no direct or circumstantial evidence for carrier status or pathogen transmission in the genus. Results Based on information from the Norwegian Pet Trade Association, the project group listed 112 taxa (mainly species and some genera) of freshwater crayfish, crabs and shrimps that are relevant for trade in Norway. These included 38 crayfish taxa, 28 crab taxa, and 45 shrimp taxa. In addition, one marine crab was included. Sixteen species of crayfish, four species of shrimps, and two species of crabs underwent a full ecological risk assessment. The probabilities of entry both into the aquarium trade in Norway, and potentially further into Norwegian nature, were based on the prevalence of the species in the aquarium trade in Norway. We assumed that all species were equally likely to escape captivity or to be .........
Authors
Claus Rasmussen Yoko L. Dupont Henning Bang Madsen Petr Bogusch Dave Goulson Lina Herbertsson Kate Pereira Maia Anders Nielsen Jens M. Olesen Simon G. Potts Stuart P. M. Roberts Markus A. K. Sydenham Per KrygerAbstract
A recurrent concern in nature conservation is the potential competition for forage plants between wild bees and managed honey bees. Specifically, that the highly sophisticated system of recruitment and large perennial colonies of honey bees quickly exhaust forage resources leading to the local extirpation of wild bees. However, different species of bees show different preferences for forage plants. We here summarize known forage plants for honey bees and wild bee species at national scale in Denmark. Our focus is on floral resources shared by honey bees and wild bees, with an emphasis on both threatened wild bee species and foraging specialist species. Across all 292 known bee species from Denmark, a total of 410 plant genera were recorded as forage plants. These included 294 plant genera visited by honey bees and 292 plant genera visited by different species of wild bees. Honey bees and wild bees share 176 plant genera in Denmark. Comparing the pairwise niche overlap for individual bee species, no significant relationship was found between their overlap and forage specialization or conservation status. Network analysis of the bee-plant interactions placed honey bees aside from most other bee species, specifically the module containing the honey bee had fewer links to any other modules, while the remaining modules were more highly inter-connected. Despite the lack of predictive relationship from the pairwise niche overlap, data for individual species could be summarized. Consequently, we have identified a set of operational parameters that, based on a high foraging overlap (>70%) and unfavorable conservation status (Vulnerable+Endangered+Critically Endangered), can guide both conservation actions and land management decisions in proximity to known or suspected populations of these species.
Abstract
Pollination sustains biodiversity and food security, but pollinators are threatened by habitat degradation, fragmentation, and loss. We assessed how remaining forest influenced bee visits to flowers in an oil palm-dominated landscape in Borneo. We observed bee visits to six plant species: four crops (Capsicum frutescens L. “chili”; Citrullus lanatus (Thunb.) Matsum & Nakai “watermelon”; Solanum lycopersicum L. “tomato”; and Solanum melongena L. “eggplant”); one native plant Melastoma malabathricum L. “melastome”; and the exotic Turnera subulata Smith “turnera”. We made one local grid-based and one landscape-scale transect-based study spanning 208 and 2130 m from forest, respectively. We recorded 1249 bee visits to 4831 flowers in 1046 ten-min observation periods. Visit frequency varied among plant species, ranging from 0 observed visits to S. lycopersicum to a mean of 0.62 visits per flower per 10 min to C. lanatus. Bee visitation frequency declined with distance from forest in both studies, with expected visitation frequency decreasing by 55% and 66% at the maximum distance from forest in each study. We also tested whether the distance to the nearest oil palm patch, with a maximum distance of 144 m, influenced visitation, but found no such associations. Expected visitation frequency was 70%–77% lower for plants close to a 200 ha forest fragment compared with those near large continuous forests (>400 ha). Our results suggest that, although found throughout the oil palm-dominated landscape, bees depend on remaining forests. Larger forests support more bees, though even a 50 ha fragment has a positive contribution. Abstract in Indonesian is available with online material.
Authors
Mani Shrestha Jair E. Garcia Freya Thomas Scarlett R. Howard Justin H. J. Chua Thomas Tscheulin Alan Dorin Anders Nielsen Adrian G. DyerAbstract
There is increasing interest in developing urban design principles that incorporate good ecological management. Research on understanding the distribution and role of beneficial pollinating insects, in particular, is changing our view of the ecological value of cities. With the rapid expansion of the built environment comes a need to understand how insects may be affected in extensive urban areas. We therefore investigated insect pollinator capture rates in a rapidly growing and densely urbanized city (Melbourne, Australia). We identified a remnant native habitat contained within the expansive urban boundary, and established study sites at two nearby populated urban areas. We employed standard pan trap sampling techniques to passively sample insect orders in the different environments. Our results show that, even though the types of taxonomic groups of insects captured are comparable between locations, important pollinators like bees and hoverflies were more frequently captured in the remnant native habitat. By contrast, beetles (Coleoptera) and butterflies/moths (Lepidoptera) were more frequently observed in the urban residential regions. Our results suggest that the maintenance of native habitat zones within cities is likely to be valuable for the conservation of bees and the ecosystem services they provide.
Authors
Markus A. K. Sydenham Zander Venter Trond Reitan Claus Rasmussen Astrid Brekke Skrindo Daniel Ingvar Jeuderan Skoog Kaj-Andreas Hanevik Stein Joar Hegland Yoko L. Dupont Anders Nielsen Joseph Chipperfield Graciela RuschAbstract
1. Predicting plant–pollinator interaction networks over space and time will improve our understanding of how environmental change is likely to impact the functioning of ecosystems. Here we propose a framework for producing spatially explicit predictions of the occurrence and number of pairwise plant–pollinator interactions and of the species richness, diversity and abundance of pollinators visiting flowers. We call the framework ‘MetaComNet’ because it aims to link metacommunity dynamics to the assembly of ecological networks. 2. To illustrate the MetaComNet functionality, we used a dataset on bee–flower networks sampled at 16 sites in southeast Norway along with random forest models to predict bee–flower interactions. We included variables associated with climatic conditions (elevation) and habitat availability within a 250 m radius of each site. Regional commonness, site-specific distance to conspecifics, social guild and floral preference were included as bee traits. Each plant species was assigned a score reflecting its site-specific abundance, and four scores reflecting the bee species that the plant family is known to attract. We used leave-one-out cross-validations to assess the models' ability to predict pairwise plant–bee interactions across the landscape. 3. The relationship between observed occurrence or absence of interactions and the predicted probability of interactions was nearly proportional (GLMlogistic regression slope = 1.09), matching the data well (AUC = 0.88), and explained 30% of the variation. Predicted probability of interactions was also correlated with the number of observed pairwise interactions (r = 0.32). The sum of predicted probabilities of bee–flower interactions were positively correlated with observed species richness (r = 0.50), diversity (r = 0.48) and abundance (r = 0.42) of wild bees interacting with plant species within sites. 4. Our findings show that the MetaComNet framework can be a useful approach for making spatially explicit predictions and mapping plant–pollinator interactions. Such predictions have the potential to identify areas where the pollination potential for wild plants is particularly high, and where conservation action should be directed to preserve this ecosystem function. interactions, network, plants, pollinators, predict, random forest
Abstract
Pollinating insects are an inherent part of most terrestrial ecosystems as they provide a crucial service for most angiosperms, including numerous important crops. A decrease in pollinator populations can therefore have severe consequences for both natural ecosystems and agricultural yields. Pesticide usage has been pointed out as one of the drivers behind pollinator declines. Globally, neonicotinoids are one of the most commonly used insecticides and studies have shown that exposure at sub-lethal levels can alter foraging behaviour, ultimately negatively affecting survival. Using a custom-made bumblebee colony monitoring system, we examined how the number and duration of foraging bouts of bumblebees (Bombus terrestris) on an individual level, and hive growth rate, was affected by exposure to low (6.5 µg/L) and high (10.6 µg/L) sub-lethal concentrations of the neonicotinoid clothianidin via nectar. We also examined possible interaction between clothianidin exposure and abiotic factors (temperature and precipitation), and its impact on foraging bout number and duration. Exposure to sublethal concentrations of clothianidin increased foraging bout duration in bumblebees. Furthermore, the foraging bout duration decreased with increasing temperature at both exposure concentrations, whereas the unexposed control group was not affected by temperature. Neither number of foraging bouts nor the daily rhythm of foraging bout duration was affected by clothianidin exposure or temperature. The foraging bout duration decreased with increasing precipitation in both exposed and non-exposed groups. However, we did not find any interaction between precipitation and exposure, suggesting that precipitation does not affect toxicity. Our study shows the importance of semi-natural experiments and accounting for ambient factors when assessing the risk that pesticide exposure may present to pollinators. We conclude that the effect of clothianidin exposure on bumblebee foraging behaviour is temperature sensitive and that local climatic conditions and future climate change scenarios should be considered in risk assessments of clothianidin and other insecticides.
Authors
Stefano Zanotto Anna Palmé Áslaug Helgadóttir Kristin Daugstad Mika Isolahti Linda Öhlund Petter Marum Maria Ahlin Moen Merja Veteläinen Odd Arne Rognli Åshild ErgonAbstract
Red clover (Trifolium pratense L.) is the most important forage legume in the Nordic region, but its utilization is limited by poor persistency. The improvement of cultivated red clover can potentially take advantage of the numerous wild populations and landraces conserved in gene banks; however, there is often limited information available on the phenotypic and genetic characteristics of this material. We characterized 48 populations conserved at NordGen for a number of traits and compared them to commercial cultivars. The material was evaluated in field trials at four locations over two years and in an experiment under controlled conditions. Considerable variation was identified, with stem length, growth type and flowering date having the highest broad sense heritabilities. Traits related to plant size were strongly associated with late flowering and upright growth and differed between landraces/cultivars on the one hand and wild populations on the other. There was a large genotype by environment interaction on winter survival, which only partially correlated with freezing tolerance under controlled conditions. A majority of gene bank accessions exceeded the commercial cultivars in winter survival and freezing tolerance and can therefore be a genetic resource for future improvement of these traits. The phenotypic variation among accessions was associated with two main axes of climatic variation at the collection site. Petiole length of young plants under controlled conditions as well as plant size in the field increased with increasing summer temperature and decreasing summer precipitation, while number of leaves and an apparent vernalization requirement, recorded under controlled conditions, increased with decreasing annual and winter temperature. We discuss the implications these results have for collection, conservation and utilization of red clover genetic resources in the Nordic region.
Abstract
Transhumance landscapes are sensitive semi-natural environments in upland European areas. Shaped through human activities from the earliest times, they provide habitat for many threatened species and produced a rich cultural heritage. They bear witness to the complex and mutually beneficial interplay between natural resources and human activities. Today, they are threatened by societal, economic and ecological factors. The purpose of this article is to identify the roles and intangible values of transhumance systems through the analysis of three studies, in Norway, France and Spain, and to raise awareness about the benefits of continuous traditional transhumance practices for the preservation of pastoral biodiversity and the mountain landscapes’ character.