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| 2. |
- Auffret, Alistair G., et al.
(author)
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HistMapR : Rapid digitization of historical land-use maps in R
- 2017
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In: Methods in Ecology and Evolution. - 2041-210X. ; 8:11, s. 1453-1457
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Journal article (peer-reviewed)abstract
- Habitat destruction and degradation represent serious threats to biodiversity, and quantification of land-use change over time is important for understanding the consequences of these changes to organisms and ecosystem service provision. Comparing land use between maps from different time periods allows estimation of the magnitude of habitat change in an area. However, digitizing historical maps manually is time-consuming and analyses of change are usually carried out at small spatial extents or at low resolutions. HistMapR contains a number of functions that can be used to semi-automatically digitize historical land use according to a map's colours, as defined by the RGB bands of the raster image. We test the method on different historical land-use map series and compare results to manual digitizations. Digitization is fast, and agreement with manually digitized maps of around 80-90% meets common targets for image classification. We hope that the ability to quickly classify large areas of historical land use will promote the inclusion of land-use change into analyses of biodiversity, species distributions and ecosystem services.
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| 4. |
- Björk, Alexandra, et al.
(author)
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The Need for Awareness of Semantic Plasticity in International Harmonization of Geographical Information : Seen from a Nordic Forest Classification Perspective
- 2015
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In: Land Use and Land Cover Semantics. - Boka Raton : CRC Press. - 9781482237399 ; , s. 41-58
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Book chapter (peer-reviewed)abstract
- The aim of this chapter is to address and clarify the important issues and challenges of semantic plasticity when it comes to forest classification and geographical information. Necessary improvements for international data harmonization and implementation are highlighted along with the need for increased awareness of the consequences for ecological modeling. We envisage a combination of thoroughly described metadata and controlled vocabularies as a means to ensure the future use of a wide range of regional and national classification systems in an ontological framework that enables crosswalks between classification systems and spatial comparisons between existing data sets. This would allow for a wide range of old, contemporary, and future data sets to be used together in landscape-related analyses.
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| 5. |
- Bunce, R. G. H., et al.
(author)
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A standardized procedure for surveillance and monitoring European habitats and provision of spatial data
- 2008
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In: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 23, s. 11-25
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Journal article (peer-reviewed)abstract
- Both science and policy require a practical, transmissible, and reproducible procedure for surveillance and monitoring of European habitats, which can produce statistics integrated at the landscape level. Over the last 30 years, landscape ecology has developed rapidly, and many studies now require spatial data on habitats. Without rigorous rules, changes from baseline records cannot be separated reliably from background noise. A procedure is described that satisfies these requirements and can provide consistent data for Europe, to support a range of policy initiatives and scientific projects. The methodology is based on classical plant life forms, used in biogeography since the nineteenth century, and on their statistical correlation with the primary environmental gradient. Further categories can therefore be identified for other continents to assist large scale comparisons and modelling. The model has been validated statistically and the recording procedure tested in the field throughout Europe. A total of 130 General Habitat Categories (GHCs) is defined. These are enhanced by recording environmental, site and management qualifiers to enable flexible database interrogation. The same categories are applied to areal, linear and point features to assist recording and subsequent interpretation at the landscape level. The distribution and change of landscape ecological parameters, such as connectivity and fragmentation, can then be derived and their significance interpreted.
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| 6. |
- Christensen, Pernilla, et al.
(author)
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Fåglar i ett landskapsperspektiv – ett samarbete mellan Nationell Inventering av Landskapet i Sverige (NILS) och Svensk Fågeltaxering (SFT)
- 2011
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Reports (other academic/artistic)abstract
- Syftet med denna studie var tvådelat där den första delen var att ta fram en effektiv flygbildsinventeringsmetodik för att kunna inventera ett större landskapsutsnitt än 1 x 1 km rutan och den andra delen var att hitta ett samband mellan myrfåglar och de landskapsdata som vi kunde plocka fram med den nya metodiken. Den flygbildsinventeringsmetodik som tagits fram under detta projekt medför att ett större område (3 x 3 km) kan inventeras på relativt kort tid (i genomsnitt 2 dagar). Tidsåtgången för att inventera hela 5 x 5 km rutan med denna metodik uppskattas till ca 3 dagar. Skillnaden från ordinarie NILS metodik är att betydligt större strukturer fångas upp eftersom karteringsenheten är större men även att detaljrikedomen som finns inom ordinarie NILS har fått minska betydligt. Med tiden finns förhoppningen att kunna effektivisera denna typ av flygbildsinventering än mer då den flygbildsinventeringstid som lagts ned under detta projekt även räknar in utveckling av metoden. I väntan på att nya möjligheter skall utvecklas skulle den metodik som vi tagit fram kunna utgöra en bra stomme för fortsatt verksamhet på en större skala än 1 x 1 km. Våra analyser av fågelarter på myrar och landskapsdata visade att fågeldata utgjorde för lite data för att vi skulle kunna se tydliga mönster samt kunna gå ned på den detaljnivå dvs. finindelning av myren, som vi ville. Tanken med den framtagna flygbildsinventeringsmetodiken var att ge data som passade för fler organismgrupper än fåglar samt att dessa data skulle kunna nyttjas även inom andra projekt såsom lillNILS. På grund av att projektet försökte svara mot både ett specifikt behov (SFT:s) samt ett mer generellt så kan vi konstatera att valet av rutor inte blev helt optimalt för att matcha landskapsdata från myrar med fågeldata. Vid fortsatta analyser kan det vara lämpligt att göra ett urval av de rutor som ligger i områden där dessa arter har sitt häckningsområde för att på så sätt begränsa antalet rutor med noll förekomst av dessa arter. Dessutom är det önskvärt att analysera flera NILS-rutor med en totalarea av myrar mellan 150 och 220 ha.
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| 7. |
- Eriksson, Sofia, et al.
(author)
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Addressing semantics and historical data heterogeneities in cross-temporal landscape change analyses
- 2010
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In: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 139:139, s. 516-521
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Journal article (peer-reviewed)abstract
- The process of recreating historical land cover dynamics, needed to understand trends and transient states in ecosystems, includes difficulties such as the sensitivity of applied spatial analyses to heterogeneities in historical material. This paper compares the handling of quantitatively dominating categories in two matrix analyses of land cover change within a Swedish boreal landscape (1725–1859). The focus is on how inconsistencies between historical maps can be handled without violating the inherent semantic potential. The study shows that analyses of land cover support different indications of change depending on the treatment of dominating categories. The type of landscape and research questions in focus should therefore be part of choosing matrix method and classification scheme. The observed patterns need to be evaluated against drivers of change and semantic plasticity in classification schemes to separate ecological change from semantic confusion. This paper recommends aggregated classification schemes with maintained original relationships between categories in comprehensive analyses. However, no pathway is persistent over time and categories should be allowed to disappear and new to appear. Analysis of historical dynamics with extended transition matrixes is recommended to account for the dynamics of small categories in relation to dominating categories within a landscape.
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| 8. |
- Eriksson, Sofia, 1977-
(author)
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Cross-scale perspectives on heterogeneity in Swedish boreal forests
- 2011
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Doctoral thesis (other academic/artistic)abstract
- Maintaining species diversity, ecosystem functioning, and socioeconomic values requires continued ecosystem heterogeneity across scales. This thesis aims to bridge gaps between ecological theory, environmental goals, and practical application of sustainable forest management needed to maintain such heterogeneity. Included case studies of boreal Sweden concern three challenges in the cross-scale understanding of heterogeneity: matrix qualities and composition; acquiring and incorporating historical information; and interactions between forest composition and management. Paper I cover three large-scale forest companies in four boreal counties today, outlining available information on matrix qualities and composition from the companies. Papers II-III cover the village scale from 1720s–1850s–present in Dalarna County and papers IV-V the parish scale from 1860s–present in the same county. Geographic Information Systems were used to integrate historical maps with present data, perform spatiotemporal analyses, and extract data for statistical testing in primarily generalized linear models. For the practical realization of sustainable forest management, the results indicate a need for further monitoring across scales to understand matrix composition, especially in relation to small voluntary reservations in a larger spatiotemporal perspective. Historical material can provide information on temporal connectivity and spatial separation between the past and present forest composition from analysis of change trajectories respectively interacting variables. This thesis suggests that models of forest dynamics are more relevant for local implementation of sustainable forest management efforts if including interactions between forest dynamics and ownership as an approximate driver of local change.
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| 9. |
- Eriksson, Sofia, et al.
(author)
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Current distribution of older and deciduous forests as legacies from historical use patterns in a Swedish boreal landscape (1725–2007)
- 2010
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In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 260:7, s. 1095-1103
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Journal article (peer-reviewed)abstract
- We combine historical maps and satellite derived data to reconstruct the development of a Swedish boreal landscape over the past 300 years. The aim is to understand legacies from past use patterns in present-day forest composition and consequences for conservation objectives from a landscape perspective. We analyze landscape development in cross-tabulation matrixes, building change trajectories. These trajectories are tested in linear models to explain the distribution of present-day landscape composition of coniferous, mixed, and deciduous forests >110 years. Of 49 tested change trajectories, 11 showed a significant association. Associations for mixed and coniferous forests were similar and linked to characteristics such as forest continuity, which characterized the studied landscape. Deciduous older forests did not show any association to forest continuity but were more likely to occur on areas that specifically shifted from forests with grazing in the 1720s to open impediment (likely indicating low tree coverage) in the 1850s. There were large shifts and spatial redistribution in ownerships over time. Use patterns and legacies varied between small- and large-scale ownership categories as well as within small-scale categories. The legacies found in the study indicate a complex origin of heterogeneous landscape elements such as older deciduous forests. Additionally, the origin of the legacies indicates a potential need to diversify conservation management based on the influence of past use patterns. Despite large inconsistencies in historical and contemporary data we argue that this type of analysis could be used to further understand the distribution of landscape elements important for conservation objectives.
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| 10. |
- Erlandsson, Rasmus, et al.
(author)
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An innovative use of orthophotos - possibilities to assess plant productivity from colour infrared aerial orthophotos
- 2019
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In: Remote Sensing in Ecology and Conservation. - : Wiley. - 2056-3485. ; 5:4, s. 291-301
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Journal article (peer-reviewed)abstract
- Studies of ecological processes should focus on a relevant spatial scale, as crude spatial resolution will fail to detect small scale variation which is of potentially critical importance. Remote sensing methods based on multispectral satellite images are used to assess primary productivity and aerial photos to map vegetation structure. Both methods are based on the principle that photosynthetically active vegetation has a characteristic spectral signature. Yet they are applied differently due to technical differences. Satellite images are suitable for calculations of vegetation indices, for example Normalized Difference Vegetation Index (NDVI). Colour infrared aerial photography was developed for visual interpretation and never regarded for calculation of indices since the spectrum recorded and post processing differ from satellite images. With digital cameras and improved techniques for generating colour infrared orthophotos, the implications of these differences are uncertain and should be explored. We tested if plant productivity can be assessed using colour infrared aerial orthophotos (0.5 m resolution) by applying the standard NDVI equation. With 112 vegetation samples as ground truth, we evaluated an index that we denote rel‐NDVIortho in two areas of the Fennoscandian mountain tundra. We compared the results with conventional SPOT5 satellite‐based NDVI (10 m resolution). rel‐NDVIortho was related to plant productivity (Northern area: P = <0.001, R2 = 0.73; Southern area: P = <0.001, R2 = 0.39), performed similar to SPOT5 satellite NDVI (Northern area: P = <0.001, R2 = 0.76; Southern area: P = <0.001, R2 = 0.40) and the two methods were highly correlated (cor = 0.95 and cor = 0.84). Despite different plant composition, the results were consistent between areas. Our results suggest that vegetation indices based on colour infrared aerial orthophotos can be a valuable tool in the remote sensing toolbox, offering a high‐spatial resolution proxy for plant productivity with less signal degradation due to atmospheric interference and clouds, compared to satellite images. Further research should aim to investigate if the method is applicable to other ecosystems.
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