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.
2017
Abstract
No abstract has been registered
Authors
Rumen Tomov René Eschen Jean-Claude Grégoire Christo Nikolov Andrei Orlinski Alberto Santini Tiit Maaten Halldors Sverrisson Bjørn Økland Anna Maria VettrainoAbstract
Sentinel plantings are a powerful tool to identify harmful organisms before they arrive in a country, but the use of this novel tool is limited by reduced awareness. Another limitation for the establishment of sentinel nurseries are plant health regulations that affect the import of planting material of alien species for use in sentinel plantings. However, import of propagation material is often considered low risk compared to rooted plants and more relaxed regulations may apply. Import regulations may vary among countries and special conditions for import for scientific purposes may apply. We aimed to make an overview of regulations for import and planting of propagation material for use in sentinel plantings in countries around the world. During 2016 a questionnaire survey was conducted in more than 40 countries around the world to identify national legislation on the import of seeds of exotic tree species and their use for scientific purposes in open-field situations. This study will provide an overview on regulations that need to be observed while sentinel nurseries are settled both using seeds for planting and trees grown from these seeds. The results will be a useful tool to facilitate the selection of locations for future sentinel nurseries.
Abstract
National parks are established to reduce human influence on nature and contribute to species conservation, biodiversity and ecological services. Other states of protection like the UNESCO world heritage sites, for example, are created for maintaining culturally important places or lifestyles. In the Matobo Hills (Zimbabwe) both states of protection are present, a national park and a world heritage site. In addition, the land outside the National Park belongs to two different systems of ownership, namely “common” (i.e. community-owned) and “not-common” (privately or governmentally owned) land. In this paper, we investigated how the state of protection and the ownership affected the land use and land cover. We derived maps using Landsat images from 1989, 1998 and 2014 by supervised classification with Random Forests. To compensate for the lack of ground data we inferred past land use and land cover from recent observations combining photographs, Google Earth images and change detection. We could identify four classes, namely shrub land, forest, patchy vegetation and agricultural area. The Matobo National Park showed a stable composition of land cover during the study period and the main changes were observable in the surroundings. Outside the national park, forest increased by about 7%. The common lands have changed substantially and their agricultural area decreased. We attribute this development to the Fast Track Land Reform, which took place in the early 2000s. Our approach shows that combining information on recent land cover with change detection allows to study the temporal development of protected areas.
Abstract
No abstract has been registered
Abstract
Angiostoma norvegicum n. sp. (Angiostomatidae) is described from the oesophagus, crop and the buccal mass of five species of slugs of the family Arionidae, Arion vulgaris (Moquin-Tandon), Arion ater (L.), Arion fasciatus (Nilsson), Arion fuscus (Müller) and Arion rufus/Arion ater hybrid), collected throughout Norway. Angiostoma norvegicum n. sp. was found parasitising arionids at seven of the 30 sample sites examined (23.3%), and 9.9% of all Arion spp. were infected with this nematode. The new species is characterised by its large size (4.0–8.6 mm long) and in having: lateral alae; 6 + 6 papillae at the cephalic end; a large circular mouth aperture; a spacious stoma; a pharyngeal basal bulb without valvular apparatus; an excretory pore near the base of bulb; a distal part of posterior ovary always outstretched; an anterior ovary distally nearly always outstretched; a vulva situated anterior to mid-body; long, nearly straight spicules and a small gubernaculum; three circumcloacal papillae and caudal genital papillae (GP) arranged in a pattern 1+2/3+3 with GP 5 and GP 8 opened on dorsal side of narrow bursa not reaching tail tip; short conical tails in both sexes with tips supplied by 4 short, unequal denticles. Morphologically, A. norvegicum n. sp. is similar to Angiostoma limacis Dujardin, 1845, which diagnostic characteristics are given based on examination of specimens from Norway and the UK. Conversely, the phylogenetic analyses based on D2D3 large subunit (LSU) rRNA gene sequences performed in the present study did not support the morphological affinity of these two species. Phylogenetic analyses demonstrated that although Angiostoma spp. cluster together, A. norvegicum n. sp. forms a tight monophyletic clade with the milacid nematode parasites Angiostoma margaretae Ross, Malan & Ivanova, 2011 and Angiostoma milacis Ivanova & Wilson, 2009.
Authors
Sigmund Hågvar Mikael Ohlson Daniel FløAbstract
Here, we explore 200 years of arthropod succession by using dated moraines in a Norwegian glacier foreland. Surface active beetles (Coleoptera) and spiders (Aranea) were sampled by pitfall trapping, and springtails (Collembola) and mites (Acari) were extracted from soil samples. Newly deglaciated ground was rapidly colonised by a mixture of generalists and specialists, with various life strategies. Interestingly, the pioneer community was fed by three ‘invisible’ food sources: biofilm with terrestrial diatom algae, tiny pioneer mosses and chironomid midges whose larvae were pond-living and used ancient carbon that was released by the melting glacier as an energy source. The true ‘super-pioneers’ were biofilm-eating springtails, which tracked the melting ice edge closely. Most species of beetles and springtails colonised within 80 years, while spiders and oribatid mites needed a longer time span to colonise. Topography influenced the succession pattern. Among both surface-living macroarthropods and soil-living microarthropods, we distinguished between a ‘dry’ and a ‘wet’ successional pathway with different community structure. Most arthropod species persisted after colonisation, but certain species preferring open space or low temperature were gradually excluded. Comparisons are made with botanical succession. Sampling methods, material size, and taxonomic resolution were considered critical factors when studying arthropod succession.
Authors
Sveinn Are Hanssen Christian Sonne Jan Ove Bustnes Lisbeth Schnug Sophie Bourgeon Manuel Ballesteros Igor Eulaers Truls Borg Moum Trond Vidar Johnsen Mads Kjelgaard-Hansen Dorte Herzke Veerle Jaspers Adrian Covaci Marcel Eens Duncan John Halley Kjell E Erikstad Rolf Anker ImsAbstract
We investigated the effects of parasite removal on various blood clinical–chemical variables (BCCVs). BCCVs are indicators of health, reflecting, e.g., homeostasis of liver, kidney function, and bone metabolism. The study was conducted in Norway on chicks of two predatory birds: White-tailed Eagle (Haliaeetus albicilla (L., 1758)) and Northern Goshawk (Accipiter gentilis (L., 1758)). Chicks were treated against both endoparasites (internal parasites) and ectoparasites (external parasites). We treated against ectoparasites by spraying nests with pyrethrins. Within nests, chicks were randomly treated with either an antihelminthic medication (fenbendazole) or sterile water (controls). Treatment against either ectoparasites or endoparasites led to higher levels of the bone and liver enzyme alkaline phosphatase. Bilirubin levels were lower when treated against ectoparasites, whereas bile acids were higher. Anti-endoparasite treatment led to higher creatinine levels. In Northern Goshawks, treating against endoparasites led to higher urea levels and lower potassium levels. Treatment against ectoparasites increased uric acid and urea levels and reduced bilirubin levels and protein:creatinine ratios. In conclusion, anti-parasite treatments led to changes in several BCCVs, suggesting differences in nutrient absorption and physiological state of chicks that are possibly related to the costs of parasitism, but maybe also to the parasite treatment itself. cost of parasitism, BCCVs, blood clinical–chemical variables, raptor, Northern Goshawk, White-tailed Eagle. Résumé : Nous avons étudié les effets du retrait des parasites sur différentes variables chimiocliniques du sang (VCCS). Les VCCS sont des indicateurs de santé, reflétant par exemple l’homéostasie du foie, la fonction rénale et le métabolisme osseux. L’étude a été menée en Norvège sur des oisillons de deux espèces d’oiseau prédateur, le pygargue a` queue blanche (Haliaeetus albicilla (L., 1758)) et l’autour des palombes (Accipiter gentilis (L., 1758)). Les oisillons ont été traités contre les endoparasites (parasites internes) et les ectoparasites (parasites externes). Le traitement contre les ectoparasites consistait a` vaporiser des pyréthrines sur les nids. Dans ces derniers, des oisillons ont été traités aléatoirement avec un médicament helminthicide (fenbendazole) ou de l’eau stérile (témoins). Les traitements contre les ectoparasites et les endoparasites ont tous deux mené a` des teneurs plus élevées en phosphatase alcaline, une enzyme des os et du foie. Les concentrations de bilirubine étaient plus faibles chez les individus traités contre les ectoparasites, alors que les concentrations d’acides biliaires étaient plus élevées chez ces individus. Le traitement contre les endoparasites a mené a` des concentrations de créatinine plus élevées. Chez les autours des palombes, le traitement contre les endoparasites a mené a` des concentrations d’urée plus élevées et de potassium plus faibles. Le traitement contre les ectoparasites s’est traduit par une augmentation des concentrations d’acide urique et d’urée et une diminution des concentrations de bilirubine et des rapports protéines:créatinine. En conclusion, les traitements antiparasitaires ont produit des modifications de plusieurs VCCS, qui indiqueraient des différences sur le plan de l’absorption de nutriments et de l’état physiologique des oisillons possiblement reliées aux coûts du parasitisme, mais aussi, peut-être, au traitement antiparasitaire en soi. [Traduit par la Rédaction] Mots-clés : coût du parasitisme, VCCS, variables chimiocliniques du sang, rapace, autour des palombes, pygargue a` queue blanche.
Abstract
Introduction and purpose: The ability of apple rootstocks to become infected by Neonectria ditissima, the cause of European canker, was studied over two years. Materials and methods: Rootstocks B9 and M9 with a size suitable for grafting (6-10 mm stem diameter, termed rootstocks), and smaller sized rootstocks (<5 mm stem diameter, termed transplants) of B9, M9, M26, MM106 and Antonovka were inoculated with N. ditissima at different times, either with contaminated map pins or with spore suspensions. In addition, the rootstocks were either defeathered (side shoots removed), topped (top shoot headed) or both, to create wounds that would normally occur during propagation, while wounds on transplants were made by removing leaves. Results and discussion: One month after inoculation, slightly sunken canker lesions had developed around the inoculation points of the map pins or wounds. No lesions developed on the non-inoculated controls. Map pin inoculation resulted in 30% to 89% infection and spore suspension sprayed on wounds from 5% to 45% infection. When the cankered areas were split open, brown lesions with necrotic tissue due to infection by N. ditissima appeared. The transplants of M9, M26 and MM106 inoculated with contaminated map pins in 2014 developed necrosis on 40% to 67% of the plants, but there were no differences in the incidence or severity among the different types. On the transplants of B9, Antonovka and M9 inoculated in 2015, there was more necrosis on B9 (42%) than on Antonovka (11%) and more sporulating lesions on B9 (29%) than on M9 (9%) or on Antonovka (4%). Conclusion: It can be concluded that rootstocks used for apple trees may become infected by N. ditissima, and wounds should thus be protected during propagation.
Abstract
No abstract has been registered
Abstract
This paper provides an overview of recent developments in remote and proximal sensing technologies and their basic applicability to various aspects of forest operations. It categorises these applications according to the technologies used and considers their deployment platform in terms of their being space-, airborne or terrestrial. For each combination of technology and application, a brief review of the state-of-the-art has been described from the literature, ranging from the measurement of forests and single trees, the derivation of landscape scale terrain models down to micro-topographic soil disturbance modelling, through infrastructure planning, construction and maintenance, to forest accessibility with ground and cable based harvesting systems. The review then goes on to discuss how these technologies and applications contribute to reducing impacts on forest soils, cultural heritage sites and other areas of special value or interest, after which sensors and methods necessary in autonomous navigation and the use of computer vision on forest machines are discussed. The review concludes that despite the many promising or demonstrated applications of remotely or proximately sensed data in forest operations, almost all are still experimental and have a range of issues that need to be addressed or improved upon before widespread operationalization can take place.