Gregor Levin

Scenario realism and welfare estimates in choice experiments – A non-market valuation study on the European water framework directive

Using choice experiment data for economic valuation we analyse how disbelief in survey information could affect the retrieved welfare estimates. We distinguish between two types of survey information to the respondents. The first type of information concerns the current environmental status of a water body. This information is provided prior to the valuation questions and the corresponding beliefs in the provided information are also elicited before valuation. The second type of information concerns the proposed improvements in the environmental status of the water body. We find that average welfare measures differ considerably according to whether respondents who disagree with the status quo levels and find proposed scenarios unlikely are included or not.

Semantically based reclassification of Danish land-use and land-cover information

In recent years, the availability of georeferenced data has increased substantially, as have the number of producers and users of this information. As a consequence, there is a growing need for harmonization of data, not least in its classification descriptions. Unfortunately, inadequate metadata hampers understanding of how data sets are produced and what data classes represent. This study describes how five different categorical geodata sets for Denmark, ranging from habitat registrations through maps of agricultural land use to national topographic data, are integrated and how the integrated data set is reclassified to land-use and land-cover classes. All five data sets differ with respect to data acquisition, and description and classification methodologies, and none of the data distinguish between land use and land cover. The purpose of the reclassification was to produce maps of land use and land cover, with classes being compatible with the land cover classification system (LCCS) from the Food and Agriculture Organization of the United Nations. We identified land-cover and land-use classes from the LCCS that matched Danish conditions and cross-tabulated those classes with classes from the integrated Danish data set. Based on the semantic meaning of the class names from the integrated data set, we used heuristic associational knowledge to estimate their membership in the land-use and land-cover classes. The results are three land-use maps and five land-cover maps, indicating qualitative estimates of the presence of land-cover classes measured on an ordinal scale.

Farm size and landscape composition in relation to landscape changes in Denmark

Abstract Geografisk Tidsskrift, Danish Journal of Geography 106(2): 45–59, 2006 This paper explores relationships between farm size and landscape composition in terms of densities of uncultivated landscape elements and sizes of agricultural fields. The study is based on national agricultural registers for Denmark and on aerial photo interpretation of three study areas, representing different Danish landscape types. Results indicate significantly smaller fields and significantly higher densities of uncultivated landscape elements on small farms (<25 ha). At national level, current differences between small and large farms are to some extent caused by landscape changes between 1998 and 2004. Analyses of the study areas indicate that current differences between small and large farms mainly evolved between 1982 and 2002, while the influences of changes between 1954 and 1982 are limited. Relationships between farms size and landscape composition are independent of spatial variations in soil type and slope conditions. Consequently, attention must be paid to other parameters linked to farm size. In particular, the effects on landscape composition of part-time and hobby farming, as well as production type, must be considered.

Methodology to estimate loss of semi-natural grasslands due to shrub encroachment in Denmark from 1965 to 2010–a sample-based study using dot grids on aerial photographs

Due to abandonment of agricultural management, shrub encroachment is thought to be a major threat to semi-natural grasslands in Denmark. However, no long-term, retrospective studies have been conducted to clarify the actual extent of this problem. To estimate the loss of semi-natural grassland caused by shrub encroachment, we analysed a sample of 1383 hectares of semi-natural grassland within a 5000 km2 study area located in Denmark. Applying a dot-grid-based interpretation of aerial photographs together with selected thematic data, we estimated change from semi-natural grassland to shrub for the periods 1965–1987 and 1987–2010. Our results show that 9.4% of the semi-natural grassland from 1965 had changed into shrub by 2010. The speed of loss was constant with 5% in each of the periods 1965–1987 and 1987–2010. We conclude that shrub encroachment is a major threat to the remaining semi-natural grasslands. Furthermore, we recommend our sample- and dot-grid method as a quick and robust approach for assessing retrospective land cover changes, e.g. semi-natural grasslands.

The significance of spatial fragmentation of land ownership for occurrence of scrubs on semi-natural grasslands

ContextTraditionally, studies of habitat fragmentation have focused on spatial isolation of habitats. Meanwhile, the role of fragmentation of land ownership and hence of parcelization of habitats remains, particularly in relation to management of semi-natural grasslands, not well understood.ObjectiveWe propose that, especially in a Danish context, fragmentation of land ownership leads to parcelization of semi-natural grassland habitats. This results in small parcel sizes, obstructing cost effective management in terms of grazing and mowing and consequently leads to encroachment of scrubs, threatening biodiversity.MethodsWe applied national, spatially explicit information about land ownership, management, semi-natural grasslands and vegetation height to examine the relationships between parcel size, management and the proportion of scrubs on semi-natural grasslands.ResultsResults from a regression analysis show that parcel size is significantly negatively related to proportion of scrubs; i.e. small parcels are associated with higher proportions of scrubs compared to large parcels. The results also show that the size of ownership parcels has a stronger explanatory power for the proportion of scrub compared to the size of habitat parcels, where ownership boundaries are not taken into account. Furthermore, parcels, with legal obligations for management, have significantly lower proportion of scrubs compared to parcels without management obligations.ConclusionsEfforts for conservation of and improvement of biodiversity on semi-natural grassland should pay increasing attention towards the importance of fragmentation of land ownership and parcelization of habitats. Our results point at the need for cross-farm cooperation to secure continuous grassland management to prevent scrub encroachment.

Land use driven conditions for habitat structure: A case study from the Ecuadorian Andes

Abstract This paper addresses the impact of land use on local conditions for habitat structure in the eastern Ecuadorian Andes. It is recognised that agricultural expansion, by disturbing natural land cover, often negatively affects living conditions for wild organisms. In the chosen study area, a village territory dominated by dairy farming, land use dynamics and spatial habitat structure are illustrated at village and field level. The socioeconomic and biophysical character of the site is described using field cartography, household interviews, aerial photos and a digital terrain model. The effects of agriculture on spatial habitat structure are investigated by relating field specific land cover data to land use and land rights information. Simple landscape indices are used to quantify the effect of changes in spatial habitat structure on local conditions for wild organisms. Results indicate that land use and its negative effects on habitat structure correspond closely with variations in biophysical limitations that result from the mountainous topography. At a finer scale, land use patterns are influenced by land tenure and related household-specific parameters.

Decrease in Danish semi-natural grassland - a social construct or a real-world change?

During the past century, the western hemisphere has seen a general trend of agricultural expansion on the behalf of semi-natural habitat types, such as heathlands and meadows. This has been documented in numerous studies of land use change. This trend is reflected in today’s European rural landscapes, which are dominated by intensive agriculture. However, many of these studies are based on cartographical sources, such as topographical and thematic maps, and thus prone to uncertainties regarding classification systems over time, variations in definitions of land use categories and lacking documentations of land use definitions. For this study, we conducted two change detection studies, covering the same four study areas in Denmark. The first study was based on topographic maps, and indicates a strong decline in the amount of semi-natural grassland (SNG). This was contrasted by the second study, which was based on an interpretation of aerial photos, and which indicated a much less pronounced reduction of SNGs. Year to year comparisons of these two analyses also revealed large discrepancies in the coverage of SNGs. Our results indicate that change detection studies must account for uncertainties in classifications and results should be interpreted with caution.

Connectivity of nature in the Nordic countries (CONNOR) : Assessing landscape structure in habitat monitoring in the Nordic countries - potential approaches, methods and data

Proceedings from the workshop at Roskilde Vandrehjem, Denmark, 14-15 May 2008 The Nordic countries have a common goal to halt the decline in biological diversity by 2010. Changes in the spatial str ...

Applying LPIS data to assess loss of agricultural land – experiences from Flanders and Denmark

ABSTRACT Worldwide, loss of farmland due to transition to other land uses is recognized as a major challenge. Data from the Land Parcel Identification System (LPIS) are potentially useful to assess agricultural land use dynamics as they contain detailed information on agricultural land use. In this paper, we therefore analyse data from two individual studies, one from Flanders and one from Denmark, to explore whether LPIS data are applicable to assess farmland loss. Our results show that in both Flanders and Denmark, around 4.5% of the total registered farmland area in LPIS was lost in a 5-year period (2008–2013 for Flanders and 2011–2016 for Denmark). Complementary land use data and aerial photo interpretation reveal that the majority of lost registered farmland still was in agricultural use after 5 years. Hence, the confirmed loss was only around 0.5% for Flanders and Denmark. We conclude that both Flemish and Danish LPIS data only with some difficulty are able to quantify loss of farmland and therefore question if LPIS data alone are suitable to assess change in farmland area. The major part of farmland leaving the register is most likely related to a general change in agricultural structure.

State of biodiversity in the Nordic countries : An assessment of progress towards achieving the target of halting biodiversity loss by 2010

The Nordic countries have agreed on a common target to halt the decline in biodiversity by 2010. This report aims at evaluating the 2010-target by presenting indicators that can describe trends in ...