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.
2020
Authors
Nanna Bjerregaard Pedersen Henning Matthiesen Robert A. Blanchette Gry Alfredsen Benjamin W. Held Andreas Westergaard‑Nielsen Jørgen HollesenAbstract
Climate change is expected to accelerate the microbial degradation of the many extraordinary well-preserved organic archaeological deposits found in the Arctic. This could potentially lead to a major loss of wooden artefacts that are still buried within the region. Here, we carry out the first large-scale investigation of wood degradation within archaeological deposits in the Arctic. This is done based on wooden samples from 11 archaeological sites that are located along a climatic gradient in Western Greenland. Our results show that Ascomycota fungi are causing extensive soft rot decay at all sites regardless of climate and local environment, but the group is diverse and many of the species were only found once. Cadophora species known to cause soft rot in polar environments were the most abundant Ascomycota found and their occurrence in native wood samples underlines that they are present locally. Basidiomycota fungi were also present at all sites. In the majority of samples, however, these aggressive and potentially very damaging wood degraders have caused limited decay so far, probably due to unfavorable growth conditions. The presence of these wood degrading fungi suggests that archaeological wooden artefacts may become further endangered if climate change leads to more favorable growth conditions.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Wood in service is sequestering carbon, but it is principally prone to deterioration where different fungi metabolize wood, and carbon dioxide is released back to the atmosphere. A key prerequisite for fungal degradation of wood is the presence of moisture. Conversely, keeping wood dry is the most effective way to protect wood from wood degradation and for long-term binding of carbon. Wood is porous and hygroscopic; it can take up water in liquid and gaseous form, and water is released from wood through evaporation following a given water vapour pressure gradient. During the last decades, the perception of wood-water relationships changed significantly and so did the view on moisture-affected properties of wood. Among the latter is its susceptibility to fungal decay. This paper reviews findings related to wood-water relationships and their role for fungal wood decomposition. These are complex interrelationships not yet fully understood, and current knowledge gaps are therefore identified. Studies with chemically and thermally modified wood are included as examples of fungal wood substrates with altered moisture properties. Quantification and localization of capillary and cell wall water – especially in the over-hygroscopic range – is considered crucial for determining minimum moisture thresholds (MMThr) of wood-decay fungi. The limitations of the various methods and experimental set-ups to investigate wood-water relationships and their role for fungal decay are manifold. Hence, combining techniques from wood science, mycology, biotechnology and advanced analytics is expected to provide new insights and eventually a breakthrough in understanding the intricate balance between fungal decay and wood-water relations.
Authors
Gunnhild SøgaardAbstract
No abstract has been registered
Authors
Erling MeisingsetAbstract
No abstract has been registered
Authors
Vebjørn Veiberg Erlend Birkeland Nilsen Christer Moe Rolandsen Morten Heim Roy Andersen Frode Holmstrøm Erling Meisingset Erling Johan SolbergAbstract
Individual age is an important element in models of population demographics, but the limitations of the methods used for age determination are not always clear. We used known-age data from moose (Alces alces), red deer (Cervus elaphus), semi-domestic reindeer (Rangifer tarandus tarandus) and Svalbard reindeer (Rangifer tarandus platyrhynchus) to evaluate the accuracy and repeatability of age estimated by cementum annuli analysis of longitudinally sectioned permanent incisors. Four observers with varying experience performed blind duplicate age estimation of 37 specimens from each cervid. The relationship between known age and estimated age was linear, except for Svalbard reindeer where a quadratic model gave a slightly better fit. After correcting for observer ID and animal ID, there was a slightly declining probability to assess the correct age with increasing age for moose, red deer and Svalbard reindeer. Across cervids and observers, estimated age equalled known age in 69% of all readings, while 95% age ± 1 year. Predicted probability of correct age assessment for experienced observers was 93% for red deer, 89% for Svalbard reindeer, 84% for moose and 73% for semi-domestic reindeer. Regardless of observer experience and cervid, there was a high agreement between repeated assessments of a given animal’s tooth sections. The accuracy varied between cervids but was generally higher for observers with former ageing experience with a given cervid. We conclude that the accuracy of estimated age using longitudinally sectioned incisors is generally high, and even more so if performed by observers with former ageing experience of a given species. To ensure consistency over time, a reference material from known-age individuals for each species analysed should be available for calibration and training of observers. Age determination . Cementumannuli analysis (CAA) . Moose . Red deer . Reindeer . Incremental layer
Authors
Hermine Mitter Anja-K. Techen Franz Sinabell Katharina Helming Erwin Schmid Benjamin Leon Bodirsky Ian Holman Kasper Kok Heikki Lehtonen Adrian Leip Chantal Le Mouel Erik Mathijs Bano Mehdi Klaus Mittenzwei Olivier Mora Knut Øistad Lillian Øygarden Jörg A. Priess Pytrik Reidsma Rüdiger Schaldach Martin SchönhartAbstract
Scenarios describe plausible and internally consistent views of the future. They can be used by scientists, policymakers and entrepreneurs to explore the challenges of global environmental change given an appropriate level of spatial and sectoral detail and systematic development. We followed a nine-step protocol to extend and enrich a set of global scenarios – the Shared Socio-economic Pathways (SSPs) – providing regional and sectoral detail for European agriculture and food systems using a one-to-one nesting participatory approach. The resulting five Eur-Agri-SSPs are titled (1) Agriculture on sustainable paths, (2) Agriculture on established paths, (3) Agriculture on separated paths, (4) Agriculture on unequal paths, and (5) Agriculture on high-tech paths. They describe alternative plausible qualitative evolutions of multiple drivers of particular importance and high uncertainty for European agriculture and food systems. The added value of the protocol-based storyline development process lies in the conceptual and methodological transparency and rigor; the stakeholder driven selection of the storyline elements; and consistency checks within and between the storylines. Compared to the global SSPs, the five Eur-Agri-SSPs provide rich thematic and regional details and are thus a solid basis for integrated assessments of agriculture and food systems and their response to future socio-economic and environmental changes.
Abstract
In the Nordic countries Finland, Norway and Sweden, the most common regeneration method is planting after clearcutting and, often, mechanical site preparation (MSP). The main focus of this study is to review quantitative effects that have been reported for the five main MSP methods in terms of survival and growth of manually planted coniferous seedlings of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) in clearcuts in these three countries. Meta analyses are used to compare the effects of MSP methods to control areas where there was no MSP and identify any relationships with temperature sum and number of years after planting. In addition, the area of disturbed soil surface and the emergence of naturally regenerated seedlings are evaluated. The MSP methods considered are patch scarification, disc trenching, mounding, soil inversion and ploughing. Studies performed at sites with predominately mineral soils (with an organic topsoil no thicker than 0.30 m), in boreal, nemo-boreal and nemoral vegetation zones in the three Fenno-Scandinavian countries are included in the review. Data from 26 experimental and five survey studies in total were compiled and evaluated. The results show that survival rates of planted conifers at sites where seedlings are not strongly affected by pine weevil (Hylobius abietis L.) are generally 80–90% after MSP, and 15–20 percent units higher than after planting in non-prepared sites. The experimental data indicated that soil inversion and potentially ploughing (few studies) give marginally greater rates than the other methods in this respect. The effects of MSP on survival seem to be independent of the temperature sum. Below 800 degree days, however, the reported survival rates are more variable. MSP generally results in trees 10–25% taller 10–15 years after planting compared to no MSP. The strength of the growth effect appears to be inversely related to the temperature sum. The compiled data may assist in the design, evaluation and comparison of possible regeneration chains, i.e. analyses of the efficiency and cost-effectiveness of multiple combinations of reforestation measures.
Abstract
No abstract has been registered