| 1. |
|
|
| 2. |
|
|
| 3. |
- Björk, Alexandra, et al.
(författare)
-
The Need for Awareness of Semantic Plasticity in International Harmonization of Geographical Information : Seen from a Nordic Forest Classification Perspective
- 2015
-
Ingår i: Land Use and Land Cover Semantics. - Boka Raton : CRC Press. - 9781482237399 ; , s. 41-58
-
Bokkapitel (refereegranskat)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.
|
|
| 4. |
- Bunce, R. G. H., et al.
(författare)
-
A standardized procedure for surveillance and monitoring European habitats and provision of spatial data
- 2008
-
Ingår i: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 23, s. 11-25
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 5. |
- Glimskär, Anders, et al.
(författare)
-
Land Type Categories as a Complement to Land Use and Land Cover Attributes in Landscape Mapping and Monitoring
- 2015
-
Ingår i: Land Use and Land Cover Semantics. - Boca Raton : CRC Press. - 9781482237399 ; , s. 171-190
-
Bokkapitel (refereegranskat)abstract
- The purpose of land cover and land use descriptions varies, and this influences how these concepts are perceived in different contexts. The increasing need for spatial data for multipurpose monitoring and modeling also increases the demands for compatibility, repeatability, detail, and well-documented criteria. We suggest that threshold values along a continuous scale can be used to create nominal classes for a common conceptual framework. However, the exact values of these thresholds need to be based on well-defined functional and systematic criteria. Ecological and environmental gradients are often mosaic and complex, and several types of land use may coexist at the same site. In reality, land use can be seen as a “shifting cloud” of activities varying in both time and space. We advocate the use of strict definitions of land cover as physical structures and land use as human activities, which raises the need for a complementary concept, which we call “land type,” with stable threshold values based on mutually exclusive functional criteria. Such functional criteria often put clear limits to what spatial resolution is appropriate, since the suitability for a certain purpose (e.g., agriculture or forestry) is determined by the user of the land, rather than by the independent observer. Our example of land type categories comprises a two-level hierarchical classification with seven main types and altogether 28 subtypes. As an example, we discuss the overlapping Swedish definitions of forest and arable land. The criteria that define our main land types are less dependent on how the area is managed at a specific moment in time, and they are therefore less sensitive to short-term variation. The land types define the limits for what land cover and land use can be expected at a certain site, given, for example, ground conditions, water, or artificial structures. Since such land types need to incorporate functional and qualitative understanding and interpretation, human visual interpretation is needed, whereas automated remote sensing methods are suitable mainly for the structural aspects of land cover.
|
|
| 6. |
|
|
| 7. |
- Käyhkö, Niina, et al.
(författare)
-
Change trajectories and key biotopes : Assessing landscape dynamics and sustainability
- 2006
-
Ingår i: Landscape and Urban Planning. - : Elsevier. - 0169-2046 .- 1872-6062. ; 75:3-4, s. 300-321
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a methodological synthesis of two congruent approaches into a common landscape change trajectory analysis and the assessment of landscape dynamics and sustainability. The emphasis of the analysis is on the retrospective relationship between the past and the present-day landscape patterns and associated key biotopes. The example key biotopes, oak woodlands and grasslands, represent valuable habitats in the hemiboreal landscapes of Finland and Sweden. The paper presents a conceptual stepwise approach for change trajectory analysis utilising multiple spatio-temporal data and techniques available in image processing and geographical information systems (GIS) including the following steps: (I) specification of spatio-temporal data and their representation of target objects, (II) the choice of direct or indirect change trajectory analysis, (III) hierarchical structuring of landscape information, (IV) compilation of landscape information into a GIS database, and (V) identification of paths for landscape change trajectory analysis. In this case study, we have focused on three interlinked trajectory analysis approaches, and their role in the assessment of landscape sustainability from a potential biodiversity perspective. We conclude that proposed landscape change trajectory analysis can improve the assessment of the key biotopes as well as present day landscape characteristics, in maintaining biodiversity and related ecological values by providing information on landscape stability, continuity, change processes and boundary dynamics. This approach can be useful in the assessment of natural capital, but requires data-specific and context sensitive data processing and analysis solutions. The results should be interpreted as an approximation and generalisation of the spatio-temporal complexity of landscape reality and therefore be used in conjunction with additional habitat function measures.
|
|
| 8. |
- Käyhkö, Niina, et al.
(författare)
-
Retrospective land cover/land use change trajectories as drivers behind the local distribution and abundance patterns of oaks in south-western Finland
- 2008
-
Ingår i: Landscape and Urban Planning. - : Elsevier. - 0169-2046 .- 1872-6062. ; 88, s. 12-22
-
Tidskriftsartikel (refereegranskat)abstract
- Valuable cultural landscapes are challenging to sustain. They are usually rare and reflect unique histories of nature–human interactions. We have studied the influence of environmental factors on the present distribution, age and abundance of oaks in a unique forest site in south-western Finland. The Landscape Change Trajectory Analysis (LCTA) approachwas tested to improve management strategies at a local level. We used geospatial analysis in GIS on existing data from a recent forest inventory, a multi-temporal land cover/land use analysis, and a digital elevation model. The results show that mature Pendunculate oaks (Quercus robur) are restricted to the eastern parts of Ruissalo island and their present abundance patterns can be linked with change trajectories as opposed to physical conditions. While the prevailing strategy of strict protection seems to lead to an increasing amount of dead wood, the lack of management hampers the regeneration of oaks. We suggest four principles for future management of these sites that could be applied throughout the hemiboreal region of Europe with similar historical development: (1) management regimes should be spatially explicit in terms of land cover history instead of treating valuable oak biotopes as one homogenous unit; (2) management units should be determined by biotope dynamics and development rather than present status and distribution; (3) management should allow strict protection of sites with long duration of protection and high abundance of decaying oak wood to support biodiversity; (4) alternative management regimes should be introduced in sites with high potential for re-establishment of light-abundant favourable conditions.
|
|
| 9. |
- Nilsson, Mats, et al.
(författare)
-
Computer classification of General Habitat Categories by combining LiDAR and SPOT data
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- General Habitat Categories (GHC) is a classification scheme developed in BioHab1, 2 and a central concept in EBONE3. A characteristic of GHC is plant height, which can be derived using Light Detection And Ranging (LiDAR) data. Computer classification of GHCs might be improved by combining spectral information in optical satellite data with LiDAR. The aim of this pilot study was to investigate to which degree airborne LiDAR improves SPOT data based classification of a selection of GHCs in a forest area in southern Sweden. Lat. 58° 30’ N Long 13° 40’ E. Managed forest with Scots pine (Pinus Sylvestris), Norway spruce (Picea Abies) and birch (Betula spp). A SPOT 5 HRG XS scene. Airborne LiDAR data with an average point density of 26 returns/m2. Photo interpretation of GHCs, 585 sample plots, in aerial DMC images. Combining LiDAR and SPOT data shows promise, considering the restrictions to this study. In a similar study, using the same dataset for classifying CORINE land cover types, overall accuracy increased from 67.1% to 77.6% when adding LiDAR data4. This means that there is potential, though the methods need improvement and further tests should include a larger test area providing adequate amounts of sample plots per GHC.
|
|
| 10. |
- Nilsson, Mats, et al.
(författare)
-
Integration of earth observation data and in situ data from the National Inventory of Landscapes in Sweden (NILS)
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Integration of in situ data and earth observation (EO) data for estimating the occurrence of different habitat or classes can be achieved using different approaches. In this study, the approach used is to post-stratify in situ data using existing land cover maps derived from satellite data. Photo-interpreted landscape elements and biotopes from the National Inventory of Landscapes in Sweden (NILS; http://nils.slu.se/) were used as in situ data. The mapped landscape elements and biotopes were classified into General Habitat Categories (GHCs). Five of the GHCs were selected to exemplify how the precision of their area estimates was affected by using post-stratification, as compared to area estimates of the GHCs based on the photo-interpreted data alone. The stratification was made using the Swedish version of Corine land cover (SMD) which includes more classes and has a higher spatial resolution (1-25 ha minimum mapping unit depending on the class) than the European version of Corine land cover (CLC). The results show that the standard error was reduced substantially for all tested GHCs using post-stratification in comparison to the errors obtained without post-stratification. This shows the potential to derive improved area statistics of habitat categories by integrating in situ data with existing land cover maps.
|
|
| 11. |
- Pitkänen, Timo P., et al.
(författare)
-
Detecting subpixel deciduous components to complement traditional land cover classifications in Southwest Finland
- 2015
-
Ingår i: International Journal of Applied Earth Observation and Geoinformation. - : Elsevier BV. - 1569-8432 .- 1872-826X. ; 42, s. 97-105
-
Tidskriftsartikel (refereegranskat)abstract
- To ensure successful conservation of ecological and cultural landscape values, detailed and up-to-datespatial information of existing habitat patterns is essential. However, traditional satellite-based and rasterclassifications rely on pixels that are assigned to a single category and often generalized. For many frag-mented key habitats, such a strategy is too coarse and complementary data is needed. In this paper,we aim at detecting pixel-wise fractional coverage of broadleaved woodland and grassland componentsin a hemiboreal landscape. This approach targets ecologically relevant deciduous fractions and com-plements traditional crisp land cover classifications. We modeled fractional components using a k-NNapproach, which was based on multispectral satellite data, assisted by a digital elevation model and acontemporary map database. The modeled components were then analyzed based on landscape struc-ture indicators, and evaluated in conjunction with CORINE classification. The results indicate that bothbroadleaved forest and grassland components are widely distributed in the study area, principally orga-nized as transition zones and small patches. Landscape structure indicators show a substantial variationbased on the fractional threshold, pinpointing their dependency on the classification scheme and grain.The modeled components, on the other hand, suggest high internal variation for most CORINE classes,indicating their heterogeneous appearance and showing that the presence of deciduous components inthe landscape are not properly captured in a coarse land cover classification. To gain a realistic perceptionof the landscape, and use this information for the needs of spatial planning, both fractional results andexisting land cover classifications are needed. This is because they mutually contribute to an improvedunderstanding of habitat patterns and structures, and should be used to complement each other.
|
|
| 12. |
- Skånes, Helle, 1964-, et al.
(författare)
-
Flygbildstolkningsmanual för Uppföljningsprojektet Natura 2000 version 4.0 : UF 19
- 2010
-
Rapport (populärvet., debatt m.m.)abstract
- Uppföljningsmanualen är indelad i fem kapitel. Kapitel 1. Ger en kortfattad bakgrund som är gemensam för hela projektet och specifik för flygbildstolkningen. Kapitel 2. Redovisar hur länsstyrelsen ska gå till väga för att på bästa sätt förbereda, planera och beställa uppföljning genom flygbildstolkning och vänder sig främst till länsstyrelsepersonalen. Flygbildstolkarna har god nytta av att känna till dessa rutiner för att på bästa sätt kunna utföra den beställda tolkningen. Här listas aktuella uppföljningsvariabler för denna manual samt ges en genomgång kring vilka naturtyper som finns föreslagna för uppföljning via flygbildstolkning i de olika uppföljningsmanualerna. Kapitel 3. Vänder sig främst till flygbildstolkarna och redovisar rekommenderad arbetsgång för flygbildstolkning. Länsstyrelsen har god nytta av att känna till detta arbetssätt inför beställning och hantering av flygbildstolkade uppföljningsdata. Kapitel 4. Går in på djupet kring de olika målindikatorer som kan beställas via flygbildstolkning och vänder sig främst till flygbildstolkarna. Länsstyrelsen har god nytta av att känna till detta arbetssätt inför såväl beställning som analys av flygbildstolkade uppföljningsdata. Kapitel 5. Kort beskrivning av förfaranden kring leverans, kontroll och godkännande av flygbildstolkade data. Detta kapitel vänder sig till alla inblandade.
|
|
| 13. |
- Skånes, Helle, 1964-, et al.
(författare)
-
Visual interpretation of key properties in vegetation structur from Lidar data : potential importance for physical, ecological and socio-economic monitoring
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper discusses early findings from one of several projects within a recently launched research program devoted to environmental mapping and monitoring with airborne laser and digital images (EMMA) financed by the Swedish EPA. Policy makers and land managers along with the global community increasingly demand hard figures regarding the state and trends of biodiversity and habitat qualities of importance to nature conservation and international environmental quality goals. Although remote sensing and GIS based methods have greatly improved, there is still a lack of spatially detailed and consistent habitat data to meet these requirements. Key vegetation qualities are often hidden from visual and automatic classification in high resolution remote sensing imagery since they are typically covered by trees. Laser beams can partly penetrate through the canopy and the data derived from the reflected pulses will add crucial detail and consistency in vegetation mapping. The aim of the project is to visually explore LiDAR data focusing on habitats within agricultural and alpine environments for enhanced vegetation classification and registration of habitat qualities and structures. Initially a number of key variables (vertical and horizontal structure, influence of land use, and site conditions) have been explored through visual interpretation of two time sets of high resolution 3D laser point data (density>5 points/m²) and derivates processed to enhance objects of interest. The initial results from a wooded pasture indicate that key properties, such as ditches, field and shrub layer characteristics and distribution, fallen trees and various man made remnants are in fact detectable. The use of laser-generated high-quality bare earth models is crucial to distinguish the field layer and low shrubs from boulders and uneven ground surface. These bare earth models will as they become widely available enhance all types of habitat modeling and landscape analysis.
|
|
| 14. |
- Skånes, Helle, 1964-, et al.
(författare)
-
Visuell tolkning av vegetationens strukturer och kvaliteter i laserskannade data
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Presentation av initiala resultat från projektets första år där nyckelegenskaper i vegetationens vertikala och horisontella struktur har formulerats och utforskats i laserskannade punktdata. Syftet är att utforska möjligheterna till visuell tolkning av nyckelgenskaper i vegetation enligt EU:s habitatdirektiv i laserdata och att undersöka i vilken utsträckning olika vegetationstyper kan skiljas genom enkla bearbetningar av laserpunktmolnet. Målet på sikt är att undersöka hur kombinationen av automatiserad och visuell tolkning av laserdata kan förbättra naturvårdsrelaterade bedömningar och automatiska vegetationsklassificeringar. Fokus ligger på habitat inom alpina miljöer, odlingslandskap och kustzonen.
|
|
| 15. |
- Torppa, Kaisa A., et al.
(författare)
-
Soil moisture and fertility drive earthworm diversity in north temperate semi-natural grasslands
- 2024
-
Ingår i: Agriculture, Ecosystems & Environment. - 0167-8809 .- 1873-2305. ; 362
-
Tidskriftsartikel (refereegranskat)abstract
- Intensive management of arable land reduces earthworm density and diversity. This may impair earthworm-mediated soil functions, such as nutrient mineralization and soil structure formation. To sustain earthworm source populations for re-colonization of cultivated soils, it is therefore important to preserve habitats with high earthworm diversity. Semi-natural grasslands, with a long continuity without soil disturbance, could serve as such earthworm diversity reservoirs. This is particularly important in mixed agricultural landscapes with elements of multiple land uses. Nonetheless, earthworm density and diversity vary greatly among grasslands. To preserve and optimally manage the most suitable grasslands, knowledge about which grassland characteristics best explain earthworm diversity is needed. Additionally, we have a limited picture of earthworm diversity in general, because previous studies have neglected juvenile earthworms and cryptic species. The juvenile fraction commonly comprises the main part of earthworm samples, whereas morphologically inseparable cryptic species account for an unknown fraction. This fraction is of particular importance, as juveniles reflect the local reproductive and regeneration potential of earthworm populations and communities. To determine the full species composition of earthworm communities, we sampled earthworms from 28 semi-natural grasslands in south-central Sweden and identified them to species by DNA barcoding. To test how grassland characteristics explain earthworm density, diversity, and community composition, we measured several characteristics of soils, vegetation, and management of the grasslands, and descriptors of the surrounding landscape. DNA barcoding revealed nearly twice as many species as were identified morphologically. Earthworm densities were higher in grasslands with higher Ellenberg moisture indicator values and lower soil C:N ratios. The diversity and occurrence of many earthworm species was also higher in grasslands with higher soil moisture indicator values and lower C:N ratios, and further increased with habitat heterogeneity. Certain species occurred more likely in grasslands with higher grazing intensity. Epigeic earthworms, which live in and feed on surface litter, were more common in grasslands with higher moisture indicator values and SOM content. Thus, dry and relatively unproductive semi-natural grasslands, which are common in Sweden, are unlikely to sustain high earthworm diversity – a pattern contrasting to previously reported plant diversity responses. Instead, earthworm diversity seems concentrated to more productive grazed grasslands, with large within-grassland heterogeneity. Therefore, we highlight the importance of considering soil animals in conservation policies for semi-natural grasslands.
|
|
| 16. |
- Ullerud, Heidrun A., et al.
(författare)
-
Bridging theory and implementation – Testing an abstract classification system for practical mapping by field survey and 3D aerial photographic interpretation
- 2019
-
Ingår i: Norsk Geografisk Tidsskrift. - : Informa UK Limited. - 0029-1951 .- 1502-5292. ; 73:5, s. 301-317
-
Tidskriftsartikel (refereegranskat)abstract
- The abstract classification system Nature in Norway (NiN) has detailed ecological definitions of a high number of ecosystem units, but its applicability in practical vegetation mapping is unknown because it was not designed with a specific mapping method in mind. To investigate this further, two methods for mapping – 3D aerial photographic interpretation of colour infrared photos and field survey – were used to map comparable neighbouring sites of 1 km2 in Hvaler Municipality, south-eastern Norway. The classification accuracy of each method was evaluated using a consensus classification of 160 randomly distributed plots within the study sites. The results showed an overall classification accuracy of 62.5% for 3D aerial photographic interpretation and 82.5% for field survey. However, the accuracy varied for the ecosystem units mapped. The classification accuracy of ecosystem units in acidic, dry and open terrain was similar for both methods, whereas classification accuracy of calcareous units was highest using field survey. The mapping progress using 3D aerial photographic interpretation was more than two times faster than that of field survey. Based on the results, the authors recommend a method combining 3D aerial photographic interpretation and field survey to achieve effectively accurate mapping in practical applications of the NiN system.
|
|
