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.
2018
Abstract
Questions : Land-cover maps are used for nature management, but can they be trusted? This study addresses three questions: (1) what is the magnitude of between field worker inconsistencies in land-cover maps and what may cause such inconsistencies; (2) in which ways and to what extent do spatial scale and mapping system influence inconsistencies between maps; and (3) are some biomes mapped more consistently than others, and if so, why? Location : Gravfjellet, Øystre Slidre municipality, southern Norway. Methods : Two different mapping systems, designed for mapping at different spatial scales, were used for parallel mapping by three different field workers, giving a total of six maps for the study area. Spatial consistency of the resulting maps was compared at two hierarchical levels for both systems. Results : The average pair-wise spatial consistency at the highest hierarchical level was 83% for both systems, while the average pair-wise spatial consistency at the lowest hierarchical level was 60.3% for the coarse system and 43.8% for the detailed system. Inconsistencies between maps were partly caused by the use of different land- cover units and partly by spatial displacement. Conclusions : Field workers made different maps despite using the same mapping systems, materials and methods. The differences were larger at lower hierarchical levels in the mapping systems and increased strongly with system complexity. Consistency among field workers should be estimated as a standard quality indicator in all field-based mapping programmes.
Abstract
Purpose Treelines and forest lines (TFLs) have received growing interest in recent decades, due to their potential role as indicators of climate change. However, the understanding of TFL dynamics is challenged by the complex interactions of factors that control TFLs. The review aims to provide an overview over the trends in the elevational dynamics of TFLs in Norway since the beginning of the 20th century, to identify main challenges to explain temporal and spatial patterns in TFL dynamics, and to identify important domains for future research. Method A systematic search was performed using international and Norwegian search engines for peer-reviewed articles, scientific reports, and MA and PhD theses concerning TFL changes. Results Most articles indicate TFL rise, but with high variability. Single factors that have an impact on TFL dynamics are well understood, but knowledge gaps exist with regard to interactions and feedbacks, especially those leading to distributional time lags. Extracting the most relevant factors for TFL changes, especially with regard to climate versus land-use changes, requires more research. Conclusions Existing data on TFL dynamics provide a broad overview of past and current changes, but estimations of reliable TFL changes for Norway as a whole is impossible. The main challenges in future empirically-based predictions of TFLs are to understand causes of time lags, separate effects of contemporary processes, and make progress on the impacts of feedback and interactions. Remapping needs to be continued, but combined with both the establishment of representative TFL monitoring sites and field experiments.
Abstract
The long history of human land use have had a strong influence on ecosystems and landscapes in the boreal forest region of Northern Europe and created semi-natural habitats of high conservation value. In this study, we quantify land-cover change and loss of semi-natural grassland in an agricultural landscape (6.2 km2 ) in the boreal region of Norway from 1960 to 2015, and document a 49.1% loss of area that was seminatural grassland in 1960. The remaining semi-natural grasslands became smaller and the connectivity between them decreased. Intensification and abandonment of agricultural land use were of approximately equal importance for the loss of semi-natural grassland although the relative contribution of these processes depended on the topography and distance to farmsteads. The study provides an example of how change in land cover can be estimated and key drivers identified on a scale that is relevant for implementation of management and conservation measures.
Authors
Eva Lieungh Eriksen Heidrun Asgeirsdatter Ullerud Rune Halvorsen Sigrun Aune Harald Bratli Peter Horvath Inger Kristine Volden Anders Kvalvåg Wollan Anders BrynAbstract
Questions: Substantial variation between observers has been found when comparing parallel land-cover maps, but how can we know which map is better? What magnitude of error and inter-observer variation is expected when assigning land-cover types and is this affected by the hierarchical level of the type system, observer characteristics, and ecosystem properties? Study area: Hvaler, south-east Norway. Methods: Eleven observers assigned mapping units to 120 stratified random points. At each observation point, the observers first assigned a mapping unit to the point independently. The group then decided on a ‘true’ reference mapping unit for that point. The reference was used to estimate total error. ‘Ecological distance’ to the reference was calculated to grade the errors. Results: Individual observers frequently assigned different mapping units to the same point. Deviating assignments were often ecologically close to the reference. Total error, as percentage of assignments that deviated from the reference, was 35.0% and 16.4% for low and high hierarchical levels of the land-covertype system, respectively. The corresponding figures for inter-observer variation were 42.8% and 19.4%, respectively. Observer bias was found. Particularly high error rates were found for land-cover types characterised by human disturbance. Conclusions: Access to a ‘true’ mapping unit for each observation point enabled estimation of error in addition to the inter-observer variation typically estimated by the standard pairwise comparisons method for maps and observers. Three major sources of error in the assignment of land-cover types were observed: dependence on system complexity represented by the hierarchical level of the land-cover-type system, dependence on the experience and personal characteristics of the observers, and dependence on properties of the mapped ecosystem. The results support the necessity of focusing on quality in land-cover mapping, among commissioners, practitioners and other end users.
Authors
Sebastian EiterAbstract
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Authors
Alexandra Kruse Naja Marot Zlata Dolacek Alduk Karl Benediktsson Michele Bottarelli Paolo Brito Csaba Centeri Sebastian Eiter Bohumil Frantál Marina Frolova Bénédicte Gaillard Viktor Grónás Maunu Häyrynen Veronica Hernández-Jiménez Richard Hewitt Marcel Hunziker Róbert Kabai Isidora Karan Malgorzata Lachowska Stanislav Martinat Georgios Martinopoulos Nieves Mestre Slobodan B. Mickovski David Miller Pia Otte José Rafael Morenes Munoz-Rochas Sina Röhner Michael Roth Olaf Schroth Alessandra Sconamiglio Mateusz Slupinski Sven Stremke Na'ama TeschnerAbstract
The COST RELY Glossary on Renewable Energy and Landscape Quality is the result of the European COST RELY project that focused on investigating the influence of renewable energy production on landscape quality. 31 people participated in developing and revising the definitions and descriptions for the 46 terms included in the glossary. Work was done in the period from 2015 to 2017 in multiple rounds of revision done by the RELY experts. Terms in the glossary are clustered into three groups: first group terms are directly connected to the landscape and its characteristics, the second one touches the planning process and methods, and the last one covers different renewable energy sources and production types. Each entry to the glossary consists of six elements: the term, definition, related terms, keywords, illustration(s) and sources. The terms are based on the expert knowledge of the contributors, scientific literature (monographs and articles), EU regulation, relevant web pages and other useful sources, stated in the Reference section. At the end of the glossary, terms are translated into 28 European languages including Esperanto. The glossary targets the researchers from the field, policy makers, local communities, investors in the sector of renewable energy and NGOs concerned with the matter in order to assure that people from different educational background and profession understand and use the term in the same manner. Beside from internal Action use, the terms shall contribute to existing glossaries on the relevant topics.
Authors
Andre Acksel Luise Giani Carolin Stasch Peter Kühn Sebastian Eiter Kerstin Potthoff Tom Regier Peter LeinweberAbstract
Some previous studies showed that the formation of several deep dark humus-rich topsoils in Northern Europe was strongly influenced by the application of different organic materials by anthropogenic activities in former times. Such topsoils classified as plaggic Anthrosols also occurred in the Jæren region in SW Norway. However, source material and formation time of these Plaggic Anthrosols have not yet been clarified. Close to this region we found further humus-rich topsoils in the Karmøy municipality (2 sites at main island of Karmøy and 1 site at Feøy). These soils show a thick humus-rich topsoil up to 30 cm, and their formation cannot only be explained by natural conditions. We analyzed the molecular signature of the soil organic matter (SOM) by benzene polycarboxylic acids (BPCA), non-targeted bulk SOM mass spectrometry, δ34S and 14C AMS dating in order to determine source materials and the age of the SOM. The black carbon (BC) contents of the plaggic soils in Jæren (mean 3.4 g kg−1) deliver clear evidence for inputs of combustion residues from ancient fire management and/or from settlements. The C-XANES and Py-FIMS-spectra reveal relative enrichments of aromatic C and heterocyclic N compounds in the plaggic soils corresponding to the BC contents. In contrast, the humus-rich topsoils in Karmøy seem to be unaffected by fire management due to the low BC contents (mean 0.6 g kg−1) and the relative low portions of aromatic C and heterocyclic N compounds from C-XANES and Py-FIMS. The δ34S isotope signature of the SOM ranged from 10.6 to 15.2‰ in the soils at the islands and 10.0 to 13.5‰ in Jæren, corresponding to the Anthrosols in the Baltic Sea region (Median: δ34S = 11.5‰) and suggest an input of marine biomass (δ34S of seaweed = 20‰). The AMS 14C dating and complementary archaeological literature implied that the soils in Jæren and Karmøy have been formed between the Roman Iron Age (500 BC to AD 500) and the Viking Age (AD 800 to AD 1,000). Our results provide strong evidence for an anthropo-pedogenesis of the humus-rich topsoils in Karmøy and indicate parallels to the plaggic soils in Jæren as well as to Anthrosols in the Baltic Sea region. Therefore, we propose to classify the humus-rich topsoils in Karmøy as Anthrosols.
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Authors
Dina Stober Matthias Buchecker Berthe Jongejan Sebastian Eiter Monika Suškevičs Stanislav Martinat Igor KuvačAbstract
No abstract has been registered