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.
2011
Abstract
Aspen (Populus tremula L.) is associated with high biodiversity and provides high-quality forage for wild browsing herbivores in boreal and temperate ecosystems. The long-term persistence of aspen in many regions in Scandinavia has been questioned due to the historically high browsing levels. We here review the basic ecology, genetics and life histories of aspen in a browsing context. Browsers can suppress the regeneration of aspen and the relatively short lifespan of the trees result in frequent regeneration cycles and concurrent exposure to browsers. In the long term, browsing may reduce recruitment and delay maturation, increase mortality and ultimately cause a decline of aspen. Norwegian forest inventory data indicate a reduced recruitment rate of young aspen (diameter at breast height; 60–79 mm) during the last 25 years, but it is unclear whether this is all due to browsing. Regeneration may also be hampered by lack of disturbance. Recent genetic studies have shown that aspen may have substantial regeneration by seeds, which allows for effective migration. The main conclusion of this review is that although browsing may affect demography and local abundance of aspen, it is very unlikely to lead to the eradication of the species in Fennoscandia.
Authors
Tim J. Mullin Bengt Andersson Jean-Charles Bastien Jean Beaulieu Rowland D. Burdon W.S. Dvorak John N. King T. Kondo Jodie Krakowski Steve J. Lee Steve E. McKeand Luc Pâques Annie Raffin John H. Russel Tore Skrøppa Michael Stoehr Alvin YanchukAbstract
This chapter reviews the historical context, economic importance, objectives and achievements to-date for many of the more important conifers undergoing domestication through genetic improvement programmes around the world. These provide examples of the context in which genomic technologies will have an impact in forestry. Unlike many other crop plants and livestock animals, forest trees have only been exposed to a few cycles of breeding and selection, and most retain very large amounts of genetic variation in natural populations. These factors present both opportunities and hurdles in the effective application of genomic technologies to existing operational breeding programmes.
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Abstract
The northernmost range of beech (Fagus sylvatica L.) is in southern Norway and consists of two distinct and isolated distributions, a single population at Seim in West Norway and several adjacent populations in Vestfold, East Norway. The modest beech pollen deposits beyond these main distributions suggest that the Norwegian beech distribution has never been an extension of the south Scandinavian range. We used genetic markers and historical sources to trace the ancestor populations for the beech at Seim and Vestfold, hypothesising Denmark as the most likely source. Nuclear inter-simple sequence repeat markers, amplified by polymerase chain reaction (PCR), were applied to estimate genetic distances between beech populations in Norway, England and Denmark. The variation in chloroplast DNA polymorphism was estimated using PCR-restriction fragment length polymorphism. The nuclear genetic data indicate Denmark as a source for the beech in Norway, although the data are less certain in the case of Seim than in that of Vestfold. The populations from South England were genetically different from most Scandinavian populations. The genetic variation within Norwegian populations was only slightly lower than that of the English and Danish populations, questioning birds as vectors for dispersal. Thus, the pollen data and our results are in accordance with the intentional introduction and documented human migrations across Skagerrak before and during the Viking Age.
Abstract
Experimental evidence shows that Norway spruce can adjust adaptive traits by a kind of long-term memory of temperature and day length present at the time of its early seed development. This mechanism is termed epigenetics; changes in gene activity not based on differences in the genetic code and yet transferable from one generation to the next. This is a rapidly growing research field in human, animal and plant genetics.
Abstract
Biodiversity is assumed to have high value for many people, but the necessary preservation also incurs a cost for the forest owner. Typically, studies of this cost are at the stand level, and hence, not very accurate as the cost may vary even within the stand. In this work, we use a 1m×1m grid, generated from LIDAR data, to estimate the cost for harvesting and forwarding. The method could be utilized to calculate compensation, and to select between key woodland habitats to minimise the cost. In three of four test cases, the main cost was reduced harvested volume, but in one case the key woodland habitat also made the harvesting operations more expensive.