A holistic framework for the analysis of landscape changes following organic farming

In this paper I reflect on the design of an appropriate methodological framework for my Ph.D.-project. Holism is widely recognised a vital concept for research on human-environment relationships. This is especially the case when agriculture’s impact on land-scapes is studied. Thus, for my study on landscape changes following conversion to or-ganic farming, I discuss holism in terms of its relevance in principal and in terms of its actual practicability. I recognise that a holistic angle is decisive in order to analyse and understand the spatial and temporal dynamics of the landscape and the multitude forces and processes that have a bearing on them. Keeping a general holistic concept in mind can elucidate factors and processes that might be overlooked in a purely reductionistic ap-proach and a holistic concept can thus prevent from drawing inadequate and premature conclusions. Additionally, in order to explain spatial and temporal dynamics in the physi-cal landscape, I discuss the integration of quantitative and qualitative methods. Quantita-tive data can point to statistical tendencies and relations. However, the underlying causes and processes, especially when these concern human activities and decision taking, can only be detected with qualitative information. Based on these considerations I suggest a holistic framework for my study where quantitative and qualitative methods in a com-plementary sense can contribute to a to a profound description and understanding of landscape changes following conversion to organic farming

Structural development in Danish agriculture and its implications for farmland nature

During the last decades, development of Danish agriculture was characterised by concentration of land on fewer and larger farms and consequently increasing farm sizes. On basis of three case studies supplemented by national data we explore relationships between farm size change and farmland nature in terms of field sizes and hedgerow densities. Data point to a significant relationship between farm enlargement and increases in mean field sizes. Furthermore, mean field size is negatively related to densities of hedgerows. For the coming decades, scenarios for Danish agriculture point to a continued increase in farm sizes. We argue for an increased focus on the effects of a continued scale enlargement on farmland nature in terms of changes in field size structure. In order to reduce harmful influences of scale enlargement, we suggest that in relation to changes in field structure, agricultural policies should focus on restrictions on removal of old hedgerows and on subsidies for planting of ne

Dynamics of Danish Agricultural Landscapes and the Roles of Organic Farming

Agriculture manages about 2/3 of the Danish land area. As a consequence, agricultural land use consequently has a major influence on the appearance of the Danish landscape in terms of its spatial composition and structure. Alterations of agricultural practices always imply potential changes in landscape composition and structure. Qua its definition and ensuing standards, organic farming embodies a particular kind of agricultural production. Consequently, the conversion to organic farming implies potential changes in the spatial composition and structure of the landscape. As organic farming occupies approx. 6% of all agricultural land in Denmark, it is relevant to investigate potential effects of this conversion on the landscape. Furthermore, within the political and public spheres organic farming is widely expected or at least supposed to have a beneficial effect on agricultural landscapes. While principles of organic farming embrace the protection and management of uncultivated landscape elements as habitats for wild species, standards and rules do, at least in Denmark, only concern cultivation practices and animal husbandry. Furthermore, research on organic farming – landscape relations is scarce and results and findings of existing studies are often biased by inadequate methods, particularly due to very small samples and limited spatial and temporal scales. Based on this background the central aim of this Ph.D. thesis is to elucidate relations between organic farming and spatial structure and composition of agricultural landscapes. Two major methodologies were applied. First, an analysis of Danish national agricultural registers from 1998, 2001 and 2004 aimed at investigating relationships between organic farming and landscape composition and structure in terms of crop diversity and field sizes. Second, an analysis for three case areas comprising 40 organic and 72 conventional farms aimed at investigating relationships between organic farming and landscape composition and structure in terms of field sizes and densities of different uncultivated landscape elements. This case area investigation was based on the interpretation of aerial photos from 1954, 1982, 1995 and 2002. Analyses at national scale pointed at significantly higher crop diversities and smaller field sizes on organic farms. In general scale enlargement in agriculture with decreasing crop diversity and increasing field sizes characterized the period from 1998 – 2004. But conversion to organic farming weakened or even reversed this trend. The case area analysis showed no significant direct relationships between organic farming and landscape composition. However, taking into account differences between organic and conventional farms with respect to other farm specific properties, the results at case area scale point at differences in landscape composition and changes in landscape composition between organic and conventional farming, which were influenced by differences in terms of farms size, soil conditions and topography. On the basis of these results it is concluded that organic agriculture as a specific type of agricultural production is characterized by a ban on chemical fertilizers. Compared to their conventional counterparts, organic farmers therefore need to maintain nutrient balances by means of a more complex crop rotation, which implies larger crop diversity and smaller field sizes. This obvious effect of organic farming has a potential to counteract some of the negative influences of a continued scale enlargement in the agricultural sector, as it is being predicted in future scenarios. Several authors argue that organic farmers due to their recognition of environmental issues are more active in landscape management inducing higher densities of uncultivated landscape elements on organic farms. Such relationship could, however, not be confirmed in this study. Differences in terms of farm sizes and soil and slope conditions lead indirectly to differences in densities of these uncultivated landscape elements between organic and conventional farms. However, differences in farm sizes as well as soil and slope conditions are not a direct consequence of organic farming standards and rules. It is thus argued that higher densities of uncultivated landscape elements on organic farms are not an outcome of organic farming as a specific type of agricultural production

Beschreibung und Differenzierung der dänischen Agrarlandschaft anhand von räumlichen Strukturindexen.

Nur wenige Untersuchungen haben sich bisher mit der Anwendbarkeit von Strukturindexen zur Beschreibung dänischer Landschaften beschäftigt. Unser Poster präsentiert eine vorläufige Studie zur Anwendbarkeit von Strukturindexen zur Beschreibung und Differenzierung dänischer Agrarlandschaften. Die Studie basiert auf einer Kombination aus dem digitalen Verzeichnis über Natur- und Halbnaturflächen, die unter Naturschutz stehen, der nationalen topographischen Karte (1:25.000) und der dänischen Karte über Agrarflächen. Die hieraus resultierende Rasterkarte wurde zu 4 Klassen in einer Matrix bestehend aus reinen Agrarflächen, bebauten Flächen etc., reklassifiziert. Die vier Klassen, auf die sich die Berechnung von Indexen basiert, sind: 1) Seen, 2) Wald, 3) Natur- und Halbnaturflächen, die in die Landwirtschaftliche Rotation eingehen (feuchte Wiese, trockene Wiese) und 4) Natur- und Halbnaturflächen, die nicht in die Rotation eingehen (Moor, Heide). Alle Indexberechnungen wurden mit FRAGSTATS 3.3 durchgeführt. 10 Strukturindexe (8 auf Klasseniveau und 2 auf Landschaftsniveau) wurden für 10 Untersuchungsgebiete, die wiederum aus 95 Gemeinden bestehen, berechnet. Die Untersuchungsgebiete repräsentieren typische dänische Naturlandschaftstypen. Die durchgeführte Analyse trägt dazu bei, die Geeignetheit der Indexe zur Landschaftsdifferenzierung auf sowohl dem Niveau der Untersuchungsgebiete sowie auf Gemeindeniveau zu untersuchen. Eine multivariate Varianzanalyse wurde für die ersten 4 Principalcomponenten aus einer PC-Analyse über die 10 Strukturindexe durchgeführt. Der nächste Schritt war eine Analyse auf Gemeindeniveau. Angewandte Variablen waren hier: Klassenindexe für jede der 4 Klassen (z.B.: pland_1, pland_2, .....pland_4) ergänzt durch die zwei Landschaftsindexe: Shannon’s Diversity Index (SIDI) und Aggregationindex (AI_LA) . Dies ergab insgesamt 34 Variabeln für jede Gemeinde. Nach einer weiteren PC-Analyse wurde eine Cluster Analyse (Wards Minimum Variance Distance) für die ersten 11 PCs mit 90% der totalen Varianz durchgeführt. Ein Histogram über Bedeutung der einzelnen Variablen für die PC’s (Factor Loadings) zeigte, dass der erste PC in erster Linie eine Dimension von „Überfluss und Aggregierung“ ziegt; der zweite PC eine Dimension von Wiese vs. Teiche/Seen; der dritte PC eine Dimension von Moor/Heide vs. Wald und Aggregierung und der vierte PC eine Dimension von Moor/Heide und Aggregierung vs. Wiese. Die Analyse des Dendogrammes zeigte Möglichkeiten von 2, 4 oder 6 Klassen. Eine Karte mit den 6 Klassen, sowie Histogramme mit den Durchschnittswerten der ursprünglichen Variablen für die einzelnen Clusters, wurde generiert. Die Karte indiziert, dass die angewandten Indexe zur Beschreibung und Differenzierung von dänischen Landschaften auf Gemeindeniveau geeignet sind. Trotzdem bleiben viele Fragen offen und folgende Themen sollten in Zukunft näher behandelt werden: - Der Einfluss von Kanteffekten (wie sollten durch Abgrenzung der Untersuchungsgebiete geteilte Flächen behandelt werden; welche Bedeutung hat es, dass man verwaltungsmäßige Größen zur Abgrenzung der Untersuchungsgebiete benutzt) - Die Wahl von Flächenklassen und die Redundanz bei der Wahl von Indexen - Die Sensitivität von Indexen, wenn sich der totale Flächenanteil aller Klassen Null näher

The decline of the Starling Sturnus vulgaris in Denmark is related to changes in grassland extent and intensity of cattle grazing

AbstractThe Danish breeding Starling population declined at a mean annual rate of −2.24%±0.39 (95% CI) during 1976–2015 (a 60% decline overall). Starling density in the mid-1990s was positively correlated with dairy cattle abundance in 13 local areas. Regional declines in Starling abundance between 2001 and 2014 were positively correlated with loss of high intensity grazing pressure by dairy cattle, as more animal husbandry moved indoors. The long-term decline in national Starling abundance was positively correlated with the long term numbers of dairy cattle grazing outdoors. This study therefore confirms that not only does the extent of available grassland to breeding Starlings affect their relative abundance, but that the intensity of grazing of these grasslands is also of importance

Comparing likely effectiveness of urban nature-based solutions worldwide: the example of riparian tree planting and water quality

Amongst a spectrum of benefits, Nature-based Solutions (NBS) are increasingly being advocated as improving the quality of aquatic environments in urban areas. Of these, a widely adopted measure is tree planting. Yet, because of the local complexities and spatial variability of urban hydrological response, it is difficult to predict to what extent improvements in water quality will arise. To overcome this barrier, a standardised approach to process-based model simulation of urban river quality is described (QUESTOR-YARDSTICK (QUESTOR-YS)). The approach eliminates the influence of point sources of pollution and harmonises the way in which river hydrodynamics and contributory catchment size are represented. Thereby, it focuses on differences in water quality between cities due solely to climate, river discharge and urban diffuse nutrient pollution factors. The relative sensitivity to NBS establishment between urban water bodies in different cities anywhere across the world can also potentially be quantified. The method can be readily extended to include wastewater effluents. The validity of the approach is demonstrated for a small river in Birmingham, UK; and thence demonstrated for the case of 10 km of riparian tree planting in Birmingham, Oslo (Norway) and Aarhus (Denmark). Modelling suggests that riparian tree planting can substantially improve water quality in each example city for three key indicators of water quality in sensitive summer conditions (water temperature, chlorophyll-a and dissolved oxygen). Results show the level of benefit achievable in response to a fixed amount of planting will depend on the existing level of riparian tree occupancy

Naturbasierte Lösungen zur Stärkung der Resilienz in Städten

Chapter 10 (in German). Als naturbasierte Lösungen (NBL) werden auf EU-Ebene naturbezogene Ansätze bezeichnet, die als Instrumente zur Bewältigung gesellschaftlicher Herausforderungen hinsichtlich des Klimawandels dienen. Eine Stadt erhöht ihre Resilienz, wenn ihre NBL-Ansätze auch soziale Probleme und das Wohlergehen der Bürger*innen ansprechen. Dieser Beitrag ist der beispielhaften Anwendung von NBL in drei europäischen Städten unterschiedlicher Größe gewidmet: einer Megacity (Region Paris, Frankreich), einer mittelgroßen Stadt (Aarhus, Dänemark) und einer Kleinstadt (Velika Gorica, Kroatien). Dabei wird untersucht, welche Herausforderungen und Chancen bei der Anwendung von NBL in verschiedenen sozialen und ökologischen Systemen auftreten und inwiefern NBL ein Schlüssel zur städtischen Resilienz sind