Adam Eindride Naas

• Naas, Adam Eindride; Horvath, Peter; Halvorsen, Rune; Sivertsen, Bendik & Bryn, Anders (2026). The impact of reference data errors on land-cover classifiers. Norsk Geografisk Tidsskrift. ISSN 0029-1951. doi: 10.1080/00291951.2026.2661590. Full text in Research Archive Show summary

  Errors in thematically detailed land-cover maps have large consequences for downstream applications. Moreover, simulation-based studies suggest that land-cover classifiers are sensitive to errors in reference data. We (1) quantified the expected error from field interpretation of land-cover types; (2) the sensitivity of classifiers to reference data errors; and (3) the error transferred from reference data to classifiers. Lastly, we (4) recommended strategies to reduce errors. The study area was mapped by 12 field interpreters divided into three equal-sized experience-level groups. The field-based land-cover maps were aggregated to three thematic resolutions and used to train 6804 land-cover classifiers by varying inputs, algorithm, and hyperparameter values. Separately from the first field campaign, four field interpreters classified validation data points, which were used to quantify error for each field interpreter and land-cover classifier, as the proportion of incorrectly classified validation points. We observed (1) generally high and varying levels of interpreter error; (2) a strong relationship between interpreter and classifier error; and (3) a net positive transfer of errors from reference data to classifiers. Because classifier error seems largely driven by interpreter error at the levels commonly observed in thematically detailed land-cover mapping, we (4) recommend strategies to reduce interpreter error before modelling.

• Naas, Adam Eindride; Simensen, Trond; Keetz, Lasse Torben; Tjessem, Ingrid Vesterdal; Bryn, Anders & Halvorsen, Rune [Show all 13 contributors for this article] (2026). Supporting spatial planning with high-spatial-resolution model-based ecosystem maps. Environmental impact assessment review. ISSN 0195-9255. 120. doi: 10.1016/j.eiar.2026.108433. Full text in Research Archive Show summary

  Field-based ecosystem maps are often used to support environmental impact assessments (EIAs) in later stages of spatial planning. During the early stages, however, information on geographical distributions of ecosystems is typically unavailable. This can result in uninformed decisions, with negative consequences for biodiversity and ecosystem services. Although model-based maps offer low-cost wall-to-wall coverage, they are rarely used for spatial planning. Using Norway as a study system, we aimed to: (1) quantify the coverage of field-based ecosystem maps in areas reserved for development; (2) use a model-based map to assess ecosystem extents in these areas; and (3) provide guidance on how model-based maps can support spatial planning. We first collated municipality-level land-use plans and intersected these with existing field-based ecosystem maps created for EIAs. Then, we constructed a model-based map for 17 ecosystem types with a 10 m × 10 m resolution that was intersected with the unsurveyed land-use plans. We estimated that 4.2 km2 of land is reserved for development in an average municipality, of which 0.3 km2 is covered by field-based maps. Our model-based map indicates, with moderate uncertainty, that 260 km2 covered by red-listed ecosystem types is at risk of being affected if unsurveyed land reserves are developed. However, improvements in model training and uncertainty quantification methodology should be considered to increase utility of the maps. We provide guidelines for using model-based ecosystem maps in spatial planning, especially in early planning stages, aiming to support decision-making while taking the limitations of model-based maps into account.

• Simensen, Trond; Bryn, Anders; Chipperfield, Joseph; Halvorsen, Rune; Naas, Adam Eindride & Töpper, Joachim Paul [Show all 8 contributors for this article] (2026). Bruk av utbredelsesmodeller for arter og naturtyper i arealplanlegging og naturforvaltning. Kart og Plan. ISSN 0047-3278. 119(1), p. 18–35. doi: 10.18261/kp.119.1.3. Full text in Research Archive Show summary

  For å ivareta naturhensyn i arealplanlegging trenger vi kunnskap om hvor arter og naturtyper finnes, om bestandsstørrelser og om økologisk tilstand. Kart over registrerte forekomster er nyttige, men ofte ufullstendige. Utbredelsesmodeller kan supplere dagens arts- og naturtypekart ved å predikere sannsynlig forekomst i hele landskapet basert på kjente funn og miljødata. Slike modeller brukes mye i økologi, men sjeldnere i arealplanlegging. Dette skyldes delvis mangel på relevante modellerte kart av god nok kvalitet, delvis at modeller kan være krevende å tolke, og delvis skepsis mot bruk av modellerte data. I denne artikkelen gir vi en kort, ikke-teknisk innføring i utviklingen innen utbredelsesmodellering, viser eksempler på ulike typer utbredelsesmodeller, og foreslår en sjekkliste til støtte for bestilling, tolkning og ansvarlig bruk av utbredelsesmodeller i planlegging og naturforvaltning.

• Tjessem, Ingrid Vesterdal; Horvath, Peter; Volden, Inger Kristine Følling; Naas, Adam Eindride; Torma, Michal & Bryn, Anders (2025). A century of treeline and forest line data for Betula pubescens subsp. czerepanovii across high elevations in Norway. Biodiversity Data Journal. ISSN 1314-2836. 13. doi: 10.3897/bdj.13.e160358. Full text in Research Archive Show summary

  Background The global climate is warming, especially in northern regions due to high-latitude amplification. This high-latitude warming leads to range expansion with advancing tree- and forest-lines (TFLs) in the Northern Hemisphere. However, empirical studies can rarely provide a well-documented elevational expansion rate, especially for timescales longer than 40–50 years. This study provides a unique long-term dataset on TFL dynamics of Betula pubescens subsp. czerepanovii in Norway, based on a combination of resampled historical data (n = 319) and new field registrations (n = 447). Our dataset includes a total of 766 registrations from five counties in Norway. In total, the dataset contains 439 treelines and 327 forest lines, most likely representing the highest recorded TFLs for the region at the given time. For all data, both resampled and new, locality, coordinates, elevation, aspect and spatial uncertainty and the resampling/sampling methods and definitions are provided. The entire material is stored and available for download through the Global Biodiversity Information Facility (GBIF) portal. New information This dataset includes newly-resampled TFLs, based on 57–127-year-old registrations. The entries provide elevational changes, georeferenced localities and potential sites for monitoring climate change effects. The entries enable regional analyses of TFL dynamics on intermediate timescales, including the effect of time lags. The material is available for modelling TFL range shifts along the boreal-alpine ecotone. This dataset most likely provides the highest registered Betula pubescens subsp. czerepanovii locations within their specific regions, thus representing the contemporary ecophysiological range limits for the life-form tree. Additional high-elevation TFL sites and localities have been added to make the material suitable for future remapping and monitoring of climatic TFL dynamics.

• Brynildsrud, Katrine Marie; Horvath, Peter; Angeloff, Michael; Dramstad, Wenche; Naas, Adam Eindride & Potthoff, Kerstin [Show all 7 contributors for this article] (2025). Forty years of urban development from northern Oslo (Norway): impacts inferred from in-situ remapping of detailed vegetation maps. Journal of Urban Ecology. 11(1). doi: 10.1093/jue/juaf010. Full text in Research Archive Show summary

  Expanding cities and urban densification is one of the major threats to biodiversity, ecosystem services and human welfare. Using Oslo, the capital city of Norway, as a case study this study addresses the following questions: (i) What vegetation changes have occurred between 1980s and 2021 and to what extent? (ii) What are the potential consequences of documented changes for biodiversity and other functions of green spaces? (iii) What future direction is the present development plan aiming for? To answer these questions, detailed vegetation maps (1:10 000) of Oslo from around 1980s were remapped in situ in 2021. We present results on land cover transformations, area statistics, and analyses of ecological impacts using landscape metrics. Our results document that large areas previously covered by vegetation types and cultivated land have been lost to urban densification. Housing dominated the new use. This loss of areas with vegetation types will affect ecosystem diversity negatively. On average, the total area and the mean patch area of each vegetation type decreased, whereas the mean Euclidean nearest-neighbor distance increased. These changes have lowered connectivity and increased fragmentation. Despite explicitly stated aims, previous efforts to reduce loss of areas with high biodiversity and maintain urban green spaces have not succeeded, and the planned future urban development indicates that a further decrease will follow in the next decades.

• Naas, Adam Eindride; Keetz, Lasse Torben; Halvorsen, Rune; Horvath, Peter; Mienna, Ida Marielle & Simensen, Trond [Show all 7 contributors for this article] (2024). Choice of predictors and complexity for ecosystem distribution models: effects on performance and transferability. Ecography. ISSN 0906-7590. 2024(8). doi: 10.1111/ecog.07269. Full text in Research Archive Show summary

  There is an increasing need for ecosystem-level distribution models (EDMs) and a better understanding of which factors affect their quality. We investigated how the performance and transferability of EDMs are influenced by 1) the choice of predictors and 2) model complexity. We modelled the distribution of 15 pre-classified ecosystem types in Norway using 252 predictors gridded to 100 × 100 m resolution. The ecosystem types are major types in the ‘Nature in Norway' system mainly defined by rule-based criteria such as whether soil or specific functional groups (e.g. trees) are present. The predictors were categorised into four groups, of which three represented proxies for natural, anthropogenic, or terrain processes (‘ecological predictors') and one represented spectral and structural characteristics of the surface observable from above (‘surface predictors'). Models were generated for five levels of model complexity. Model performance and transferability were evaluated with data collected independently of th

• Naas, Adam Eindride; Halvorsen, Rune; Horvath, Peter; Wollan, Anders Kvalvåg; Bratli, Harald & Brynildsrud, Katrine Marie [Show all 16 contributors for this article] (2023). What explains inconsistencies in field-based ecosystem mapping? Applied Vegetation Science. ISSN 1402-2001. 26(1). doi: 10.1111/avsc.12715. Full text in Research Archive Show summary

  Questions Field-based ecosystem mapping is prone to observer bias, typically resulting in a mismatch between maps made by different mappers, that is, inconsistency. Experimental studies testing the influence of site, mapping scale, and differences in experience level on inconsistency in field-based ecosystem mapping are lacking. Here, we study how inconsistencies in field-based ecosystem maps depend on these factors. Location Iškoras and Guollemuorsuolu, northeastern Norway, and Landsvik and Lygra, western Norway. Methods In a balanced experiment, four sites were field-mapped wall-to-wall to scales 1:5000 and 1:20,000 by 12 mappers, representing three experience levels. Thematic inconsistency was calculated by overlay analysis of map pairs from the same site, mapped to the same scale. We tested for significant differences between sites, scales, and experience-level groups. Principal components analysis was used in an analysis of additional map inconsistencies and their relationships with site, scale and differences in experience level and time consumption were analysed with redundancy analysis. Results On average, thematic inconsistency was 51%. The most important predictor for thematic inconsistency, and for all map inconsistencies, was site. Scale and its interaction with site predicted map inconsistencies, but only the latter were important for thematic inconsistency. The only experience-level group that differed significantly from the mean thematic inconsistency was that of the most experienced mappers, with nine percentage points. Experience had no significant effect on map inconsistency as a whole. Conclusion Thematic inconsistency was high for all but the dominant thematic units, with potentially adverse consequences for mapping ecosystems that are fragmented or have low coverage. Interactions between site and mapping system properties are considered the main reasons why no relationships between scale and thematic inconsistency were observed. More controlled experiments are needed to quantify the effect of other factors on inconsistency in field-based mapping.

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• Bryn, Anders; Brynildsrud, Katrine Marie; Folland, Amanda A.; Hemsing, Lars Østby; Horvath, Peter & Høitomt, Torbjørn [Show all 14 contributors for this article] (2025). Feltbaserte kart over arter og naturtyper: likheter, forskjeller og kart vi mangler. Biolog. ISSN 0801-0722. 3, p. 4–11. doi: https:/bio.no/images/Feltbaserte%20_kart.pdf. Full text in Research Archive Show summary

  I debatten om naturmangfold og naturforvaltning i Norge, er en tilbakevendende utfordring forståelsen av ulike feltbaserte temakart. I dette essayet beskrives grunnleggende likheter og forskjeller mellom to sentrale feltbaserte temakart over naturmangfold: artskart og naturtypekart. Disse kartene representerer ulike nivåer i hierarkiet over naturmangfold og har supplerende funksjoner i forvaltningen.

• Vloon, Catharina Caspara; Halvorsen, Rune; Nordbakken, Jørn-Frode; Naas, Adam Eindride; Auestad, Inger & Rydgren, Knut (2025). Restoration of a boreal raised bog: does the state of the reference affect predicted time to recovery? Full text in Research Archive
• Naas, Adam Eindride (2025). Ecosystem mapping – propagation of uncertainty from field-based maps to downstream applications. Full text in Research Archive
• Naas, Adam Eindride; Horvath, Peter; Halvorsen, Rune; Sivertsen, Bendik & Bryn, Anders (2025). Garbage in, garbage out – propagation of errors from reference data to ecosystem distribution models. Full text in Research Archive
• Tjessem, Ingrid Vesterdal; Bryn, Anders; Horvath, Peter; Naas, Adam Eindride; Halvorsen, Rune & Berntsen, Terje Koren [Show all 10 contributors for this article] (2025). Tales from the past: remapping rising tree- and forest lines in response to changing climate and land use regimes. Full text in Research Archive
• Naas, Adam Eindride; Simensen, Trond; Keetz, Lasse Torben; Tjessem, Ingrid Vesterdal; Bryn, Anders & Halvorsen, Rune [Show all 13 contributors for this article] (2025). Ecosystem distribution models to support area management – a case study from Norway. Full text in Research Archive
• Horvath, Peter; Keetz, Lasse Torben; Nilsen, Anne-Barbi & Naas, Adam Eindride (2025). Nature in Norway - QGIS plugin. Full text in Research Archive
• Naas, Adam Eindride (2024). Are ecosystem maps good enough? Full text in Research Archive
• Bryn, Anders; Berntsen, Terje Koren; Horvath, Peter; Isaksen, Ketil; Liahjell, Gunnar Thorsen & Naas, Adam Eindride [Show all 10 contributors for this article] (2024). På vei mot nye høyder: tre- og skoggrensene stiger. Arr - Idéhistorisk tidsskrift. ISSN 0802-7005. p. 87–100. Full text in Research Archive
• Vandvik, Vigdis; Töpper, Joachim Paul; Velle, Liv Guri; Chipperfield, Joseph; Klimes, Adam & Naas, Adam Eindride [Show all 7 contributors for this article] (2024). Modelling Ecological State and Condition to support knowledge-based decision-making in Area Management and spatial Planning (ECoMAP). Full text in Research Archive
• Naas, Adam Eindride; Keetz, Lasse Torben; Halvorsen, Rune; Horvath, Peter; Simensen, Trond & Mienna, Ida Marielle [Show all 7 contributors for this article] (2023). Distribution modelling of ecosystems in Norway - comparison of two modelling approaches and different types of predictors. Full text in Research Archive
• Naas, Adam Eindride; Bryn, Anders; Halvorsen, Rune; Horvath, Peter; Keetz, Lasse Torben & Mienna, Ida Marielle [Show all 7 contributors for this article] (2023). Dynamic predictors improve ecosystem models. Full text in Research Archive
• Naas, Adam Eindride; Halvorsen, Rune; Horvath, Peter; Wollan, Anders Kvalvåg; Bratli, Harald & Brynildsrud, Katrine Marie [Show all 16 contributors for this article] (2023). How consistent are NiN field mappers? Full text in Research Archive
• Bryn, Anders; Horvath, Peter; Volden, Inger Kristine; Stordal, Frode; Torma, Michal & Tjessem, Ingrid Vesterdal [Show all 7 contributors for this article] (2023). Citizen science for treeline mapping. Full text in Research Archive
• Bryn, Anders; Brynildsrud, Katrine Marie; Horvath, Peter; Keetz, Lasse Torben; Lieungh, Eva & Naas, Adam Eindride [Show all 9 contributors for this article] (2023). “Ground-truth" from field-based ecosystem mapping. Full text in Research Archive
• Tjessem, Ingrid Vesterdal; Bryn, Anders; Horvath, Peter & Naas, Adam Eindride (2023). Changing treeline: A 150-year perspective​. Full text in Research Archive
• Bryn, Anders; Horvath, Peter; Naas, Adam Eindride & Tjessem, Ingrid Vesterdal (2023). Kartlegging av naturtyper etter Natur i Norge (NiN). Biolog. ISSN 0801-0722. p. 16–23. Full text in Research Archive
• Bryn, Anders; Horvath, Peter; Torma, Michal; Naas, Adam Eindride; Volden, Inger Kristine & Liahjell, Gunnar Thorsen [Show all 10 contributors for this article] (2022). Treeline research at Natural history museum (UiO). Full text in Research Archive
• Gunnar, Thorsen Liahjell & Naas, Adam Eindride (2021). Modelling of a century with tree- and forest line changes and their climate impact. Full text in Research Archive
• Naas, Adam Eindride (2021). Modellering av skoggrenser. Full text in Research Archive
• Naas, Adam Eindride (2021). Modelling a century with tree- and forest line changes in South Norway. Full text in Research Archive
• Bryn, Anders; Naas, Adam Eindride; Horvath, Peter; Stordal, Frode; Torma, Michal & Volden, Inger Kristine [Show all 7 contributors for this article] (2002). Tree- and forest line dynamics in Norway – causes, consequences and monitoring. Full text in Research Archive
• Bryn, Anders; Haugland, Barbro Taraldset; Dolan, Margaret; Bekkby, Trine & Naas, Adam Eindride (2025). Feltveileder marint (NiN 3.0) - Regler, typetabeller og praktiske råd, Versjon 1.1. Artsdatabanken. ISSN 9788292838754. Full text in Research Archive
• Naas, Adam Eindride (2025). Ecosystem mapping: challenges and opportunities with fieldand model-based methods. Universitetet i Oslo. Full text in Research Archive Show summary

  Ecosystem maps are used to support environmental impact assessments, maintain ecosystem accounts, and calibrate climate models – which are in turn used to make environmental policy decisions. It is therefore concerning that the quality of detailed ecosystem maps is often low and variable, leading to the risk of decisions being based on incorrect information. The aim of this dissertation was to explore causes of variation in the quality of ecosystem maps. Paper I shows that the quality of field-based ecosystem maps depends on the experience of the mapper and the properties of the area being mapped. Paper II demonstrates that the quality of model-based ecosystem maps significantly improves with the use of remote sensing data for a selection of ecosystem types. Paper III illustrates how model-based ecosystem maps can be used in spatial planning and emphasises that decisions can be improved considerably if a quality assessment of the map product is available. Together, the papers highlight the challenges associated with creating detailed ecosystem maps of high quality. The dissertation provides a foundation for further method development and improved practical applications of ecosystem maps.

• Bryn, Anders; Andersen, Guri Sogn; Bekkby, Trine; Bratli, Harald; Dervo, Børre Kind & Dolan, Margaret [Show all 14 contributors for this article] (2023). Hovedveileder for feltbasert kartlegging. Terrestrisk, limnisk og marin naturvariasjon etter NiN (3.0). Artsdatabanken. ISSN 9788292838617. Full text in Research Archive
• Bryn, Anders & Naas, Adam Eindride (2023). Feltveileder terrestrisk. Regler, typetabeller og praktiske råd (NiN 3.0). Artsdatabanken. ISSN 9788292838624. Full text in Research Archive
• Bryn, Anders; Haugland, Barbro Taraldset; Dolan, Margaret; Bekkby, Trine & Naas, Adam Eindride (2023). Feltveileder marint. Regler, typetabeller og praktiske råd (NiN 3.0). Artsdatabanken. ISSN 9788292838631. Full text in Research Archive
• Dervo, Børre Kind; Naas, Adam Eindride & Bryn, Anders (2023). Feltveileder limnisk. Regler, typetabeller og praktiske råd (NiN 3.0). Artsdatabanken. ISSN 9788292838648. Full text in Research Archive

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