Change trajectories and key biotopes - Assessing landscape dynamics and sustainability

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.</p

Vegetation diversity of conventional and organic hedgerows in Denmark

Many attempts have been made to reduce the impact of modern conventional farming on the environment and semi-natural ecosystems. One of them is organic farming, known primarily for the absence of pesticides and artificial fertilisers. The objective of this study was to study and test the differences in the spontaneous vegetation of comparable hedgerows in the same area situated within organic and conventional farming systems. The hedge bottom vegetation was surveyed during August 2001 in 13 hedgerows of each farming system. Farming type had not changed on either side of the hedgerows for the lifetime of the hedges (10-14 years). Sampling was associated with a set of 16 measured environmental variables. In the two farming systems hedgerows were comparable in terms of landscape, age, soil type, nutrient status and width. A mixed analysis of variance found no significant difference in measured soil and radiation variables between farming types. Farming types only differed in the use of pesticides. Significant differences between farming types in plant species diversity at alpha, beta and gamma levels were found. Also more species that normally occur in semi-natural habitats were found on organic farms. There was an overlap in species composition between farming type, but a slightly higher species turnover on conventional farms. The ordination axes were highly correlated with calibrated Ellenberg values of fertility, light and soil moisture. Soil fFertility and farming type were important factors to explain variation in species composition. Organic farming had a significantly reduced impact on hedge bottom vegetation compared to conventional farming. Higher extinction rates due to pesticide drift and immigration rates due to pesticide drift rates oin conventional farminsg may be responsible for the significantly higher species diversity and different species composition in hedges on organic farms. The differences in species diversity and plant types are briefly discussed

HistMapR: rapid digitization of historical land-use maps in R

1. 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. 2. 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. 3. 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. 4. 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

Retrospective land cover/land use change trajectories as drivers behind the local distribution and abundance patterns of oaks in south-western Finland

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) approach was 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.</p

Bridging theory and implementation – Testing an abstract classification system for practical mapping by field survey and 3D aerial photographic interpretation

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

PM: Gräsmarkernas gröna infrastruktur i jordbrukslandskapet

Den regionala miljöövervakningen av gräsmarksmiljöer via NILS (Rygne 2009, Andersson &amp; Glimskär 2011) ger på sikt stora möjligheter till analyser för uppföljning av de kvalitetsinriktade delarna av de aktuella miljömålen. Alla gräsmarker och småbiotoper som inventeras är lägesangivna, vilket tillsammans med kunskaper om olika arters spridningsbiologi kommer att göra det möjligt att beskriva tillståndet och utvecklingen för spridningsmöjligheter mellan värdekärnor i jordbrukslandskapet. Övervakningen startade 2009 och det är viktigt att i ett tidigt skede, men ändå med ett par års erfarenhet, göra en utvärdering av metodiken. Detta för att på bästa sätt kunna använda data till relevanta framtida analyser för uppföljning av miljömål, och som grund för utvärdering av styrmedel med syfte att bevara och stärka biologisk mångfald i jordbrukslandskapet.Länsstyrelserna som deltar i den regionala övervakningen har lyft fram behoven av att följa alla gräsmarksmiljöer i landskapet, med tonvikt på sådana miljöer som har stor betydelse för bland annat insektsgrupper beroende av pollenkällor, sandblottor och en variationsrik, öppen och solexponerad miljö. Man behöver då vidga dagens övervakning till att även inkludera andra gräsmiljöer än i åker- och betesmark. Dessa övriga gräsmarksmiljöer kan hysa en betydande andel av landskapets biologiska mångfald och agera som spridningsmiljöer och refugier för arter som normalt återfinns i det brukade jordbrukslandskapets gräsmarksmiljöer (Figur 1). För att kunna följa även dessa gräsmarker behövs för det första en flygbildsinventering som kan beskriva totalbilden, inklusive både artrika och artfattiga gräsmarksmiljöer, både temporära och sådana med lång kontinuitet. För det andra behövs en fältinventering utformad på ett sätt som fångar de intressanta kvaliteterna på ett realistiskt och kostnadseffektivt sätt.För att utreda möjligheterna att även inkludera övriga gräsmarksmiljöer har Länsstyrelserna i Örebro, Östergötlands och Kronobergs län arbetat tillsammans med SLU/NILS inom projektet ”Gräsmarkernas gröna infrastruktur i landskapet”. Projektet har finansierats med utvecklingsmedel för regional miljöövervakning under år 2011 (Överenskommelse Nr 218 1150). Denna rapport utgör SLU:s slutleverans till projektet.Remiil, Regioal miljöövervakning i landskapsruto

Environmental mapping and monitoring with airborne laser and digital images. Application in the coastal zone of Åhus, Sweden

Demonstrationsprojektet Kustzonen - tillämpning i Åhus ingår som en del inom forskningsprogrammet EMMA. Studien avser en tillämpning för strandzonen och har genomförts för ett område i Åhus i Kristianstads kommun. Syftet är att illustrera hur batymetrisk laser, topografisk laser och flygbilder kan kombineras i övergången mellan land och vatten för att ta fram kartunderlag för kustzonsplanering. Syftet har också varit att ta fram en integrerad databas över kustzonen som beskriver såväl akvatiska som terrestra biotoper, tänkt att användas både för fysisk planering och naturvård. I studien ingår även beskrivning av vilka indikatorer/kriterier som behövs för att värdera förändringar av strandzonen för bedömning av erosionsförhållanden

An innovative use of orthophotos - possibilities to assess plant productivity from colour infrared aerial orthophotos

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 = &lt;0.001, R2 = 0.73; Southern area: P = &lt;0.001, R2 = 0.39), performed similar to SPOT5 satellite NDVI (Northern area: P = &lt;0.001, R2 = 0.76; Southern area: P = &lt;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.Fjällrävsprojekte