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.     

The Emergence of an Environmental Cartography in Denmark

Within the history of cartography, relatively little attention has been devoted to the study of the growing body of maps and spatial data focusing on environmental issues. This is rather surprising, considering the importance of this type of cartography in the handling of the complex environmental problems of modern society. This paper analyses the development of thematic maps and spatial data focusing on the terrestrial environment of Danish landscapes. The paper is introduced with a review of the concept of environmental cartography, followed by a historical analysis of the development of environmental mapping in Denmark. Results suggest that there has been a change in the content and aim of environmental cartography in the twentieth century, from an initial focus on mapping potentials for land use improvement and optimization of the economic outputs from engagement with terrestrial ecosystems, to a focus on monitoring ecosystems and regulation of human intervention. Finally, the usefulness of the concept environmental cartography to frame analytical work dealing with the still increasing number of maps produced for environmental purposes within the history of cartography, is evaluated.     

V p/V s-ratios from the central Kolbeinsey Ridge to the Jan Mayen Basin,North Atlantic; implications for lithology,porosity and present-day stress field

The horizontal components from twenty Ocean Bottom Seismometers deployed along three profiles near the Kolbeinsey Ridge, North Atlantic, have been modelled with regard to S-waves, based on P-wave models obtained earlier. Two profiles were acquired parallel to the ridge, and the third profile extended eastwards across the continental Jan Mayen Basin. The modelling requires a thin (few 100 m) layer with very high V _p/V _s-ratio (3.5–9.5) at the sea-floor in the area lacking sedimentary cover. The obtained V _p/V _s-ratios for the remaining part of layer 2A, 2B, 3 and upper mantle, correspond to the following lithologies: pillow lavas, sheeted dykes, gabbro and peridotite, respectively. All crustal layers exhibit a decreasing trend in V _p/V _s-ratio away-from-the-axis, interpreted as decreasing porosity and/or crack density in that direction. A significant S-wave azimuthal anisotropy is observed within the thin uppermost layer of basalt near the ridge. The anisotropy is interpreted as being caused by fluid-filled microcracks aligned along the direction of present-day maximum compressive stress, and indicates crustal extension at the ridge itself and perpendicular-to-the-ridge compression 12 km off axis. Spreading along the Kolbeinsey Ridge has most likely been continuous since its initiation ca. 25 Ma: The data do not suggest the presence of an extinct spreading axis between the Kolbeinsey Ridge and the Aegir Ridge as has been proposed earlier. The V _p/V _s-ratios found in the Jan Mayen Basin are compatible with continental crust, overlain by a sedimentary section dominated by shale.     

Assessing climate change impacts on the Iberian power system using a coupled water-power model

Climate change is expected to have a negative impact on the power system of the Iberian Peninsula; changes in river runoff are expected to reduce hydropower generation, while higher temperatures are expected to increase summer electricity demand, when water resources are already limited. However, these impacts have not yet been evaluated at the peninsular level. We coupled a hydrological model with a power market model to study three impacts of climate change on the current Iberian power system: changes in hydropower production caused by changes in precipitation and temperature, changes in temporal patterns of electricity demand caused by temperature changes, and changes in irrigation water use caused by temperature and precipitation changes. A stochastic dynamic programming approach was used to develop operating rules for the integrated system given hydrological uncertainty. We found that changes in precipitation will reduce runoff, decrease hydropower production (with accompanying increases in thermal generation), and increase irrigation water use, while higher temperatures will shift power demand from winter to summer months. The combined impact of these effects will generally make it more challenging to balance agricultural, power, and environmental objectives in the operation of Iberian reservoirs, though some impacts could be mitigated by better alignment between temporal patterns of irrigation and power demands.     

New multifunctional hunting landscapes in Denmark

Between 1992 and 2008 subsidization of mandatory set aside land under the EU Common Agricultural Policy (CAP) gave rise to the establishment of a characteristic type of multifunctional hunting landscapes in Denmark, primarily located on fallow land in tilled valley bottoms. A national survey of these landscapes in 2006 has been carried out and 1061 hunting areas have been identified nationwide. Subsidies relating to set aside land acted as a supplementary type of income, which supported the development of multifunctional land use on marginal soils where the income from hunting and subsidies in combination was a viable alternative to monofunctional rotational agriculture. Hunting landscapes developed as the consequence of landscape management strategies designed to comply with the requirements of the CAP while improving habitat conditions for wildlife and increasing income from hunting rental activities. Forty-seven percent of the hunting landscapes in 2006 were in rotational production in 2010 while 19% were used for other agricultural purposes and 34% were taken out of the subsidy regime and removed from the general agricultural register. In 2012, a total of 431 such areas ? 41% of the areas identified in 2006 ? were still used for hunting. The number and geographical distribution of the hunting landscapes seems closely related to the potential average hunting rent, the level of urbanisation and the occurrence of manorial estates with traditions for multifunctional land use as part of their economic strategy. Implications for the ongoing discussion on land use policy concerning land sharing vs. land sparing is discussed.