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.
2007
Authors
Einar Heegaard Rune Halvorsen Økland Harald Bratli Wenche Dramstad Gunnar Engan Oddvar Pedersen Heidi SolstadAbstract
No abstract has been registered
Abstract
After two decades of monitoring forest health in Europe, in response to concern for negative effects of air pollution, a similar worry is now increasing in China. In a co-operative project between Chinese and Norwegian researchers a forest monitoring was implemented in the acid rain region in south China. During 2000–2004 two small watersheds were monitored: TieShanPing (TSP) near ChongQing City and LuChongGuan (LCG) near GuiYang City. They are covered by Masson pine (Pinus massoniana) forest. The methodology of the European intensive forest monitoring programme (ICP-Forests level-II) was adopted; including crown assessments, foliar chemistry, air and soil chemistry, and more. This paper presents results of this co-operative project. Considerable forest damage was revealed by monitoring the crown condition of Masson pine trees. The average defoliation percentage for all assessed trees (predominant, dominant and co-dominant pines, corresponding to Kraft classes 1–3) in the more acidified TSP was over 40% and remained stable throughout the monitoring period, accompanied by an extremely high mortality in some years. In contrast, the defoliation in the less acidified LCG was relatively low but increased considerably, from 16% to around 40%, within the 4 monitoring years. The significance of air pollution for the forest damage remains uncertain. The annual SO2 concentration in TSP and LCG is about 2 and 4 times higher than the critical level of 20 μg m−3 given in the LRTAP convention for effects on forests. Therefore the air pollution effects cannot be ruled out as contributing factors for forest damage. However, this cannot be substantiated based on the presented monitoring data since none of the specific symptoms of air pollution damage were observed. Furthermore, an analysis of the monitoring data did not reveal any significant correlation between defoliation and the soil chemical properties. It is noteworthy that the evident agents that were identified are capable of causing the observed forest damage. These agents were insect attacks and climatic stress. It is possible that the forest damage has complex causes.
Abstract
No abstract has been registered
Authors
Atle Mysterud Erling Meisingset Vebjørn Veiberg Rolf Langvatn Erling Johan Solberg Leif Egil Loe Nils Christian StensethAbstract
Proper management of wildlife relies on metrics of population development. Typically, the best estimation techniques are too expensive for coarse-scale management. In marine fisheries, catch-per-unit effort is commonly used, but problems may arise due to changes in spatial harvest effort or in habitat use as density changes. Managers in Norway are in the early phases of implementing "seen deer" during harvesting and "spring counts" on farmland as a means of monitoring red deer Cervus elaphus populations. We provide a first evaluation of how suitable these methods are by comparing the results with population estimates obtained using cohort analysis, and by analysing the within-season variation in number of seen deer. "Seen deer" predicted annual increases in populations fairly well. Adjusting for harvesting effort provided less good estimates, due to a proportionally larger increase in effort relative to deer population size as population size increased. The number of seen deer per day decreased rapidly at the beginning of the season, and then levelled off or increased slightly during the rut, especially on farmland. The number of seen deer increased both with the number of harvesters and hours harvested, but at a diminishing rate. The current practice of "spring counts" was not successful in predicting population changes, probably due to a lack of replication. Indeed, date strongly affected the number of deer seen during spring counts. While "seen deer" seems to be a very promising tool for monitoring population size of red deer, there are some limitations to the practice as implemented for moose Alces alces in Scandinavia due to a more complex relationship with harvesting effort. Our study highlights that the large number of hours harvesters observe wildlife can provide a useful tool for population monitoring. However, the use of such indices may vary between species and according to harvest techniques and should thus be assessed with care before implementation
Authors
Laura Kirwan Andreas Lüscher Maria Teresa Sebastia J Finn Rosemary P Collins C Porqueddu Helga Helgadottir O. H. Baadshaug Caroline Brophy C Coran Sigridur Dalmannsdottir I Delgado A. Elgersma Mick Fothergill Bodil Frankow-Lindberg B Golinski P Grieu A.M. Gustavsson Mats Höglind O Huguenin-Elie C Iliadis Marit Jørgensen Z Karyotis Tor Lunnan M Malengier V Meyer D Nyfeler P Nykanen-Kurki J Parente H J Smit U Thumm John ConnollyAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Karlsson Magnus Ari Hietala Harald Kvaalen Halvor Solheim Åke Olson Jan Stenlid Carl Gunnar FossdalAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Charles A. Francis Andrea Lawseth Alexandra English Paula Hesje A. McCann J. Wagner Wendy Marie Waalen Geir Lieblein Tor Arvid BrelandAbstract
No abstract has been registered
Abstract
No abstract has been registered