Filtern
Dokumenttyp
- Dissertation (5)
- Bachelorarbeit (1)
Schlagworte
- Landwirtschaft (2)
- Agrarsystem (1)
- Baum (1)
- Bestäuber (1)
- Flächennutzung (1)
- Insekten (1)
- Landschaft (1)
- Landschaftsbiogeographie (1)
- Landschaftsschutz (1)
- Landschaftsökologie (1)
Institut
Traditional farming landscapes typically support exceptional biodiversity. They evolved as tightly coupled social-ecological systems, in which traditional human land-use shaped highly heterogeneous landscapes. However, these landscapes are under severe threats of land-use change which potentially pose direct threats to biodiversity, in particular through land-use intensification and land abandonment. Navigating biodiversity conservation in such changing landscapes requires a thorough understanding of the drivers that maintain the social-ecological system. This dissertation aimed to identify system properties that facilitate biodiversity conservation in traditional farming landscape, focusing specifically on birds and large carnivores in the rapidly changing traditional farmland region of Southern Transylvania, Romania. In order to identify these properties, I first examined the effects of local and landscape scale land-use patterns on birds and large carnivores and how they may be affected by future land-use change (Chapters II-V). Second, to gauge the role of particular traditional land-use elements for biodiversity I focused on the conservation value of traditional wood pastures (Chapters VI-VIII). Third, I took a social-ecological systems approach to understand how links between the social and ecological parts of the system affect human-bear coexistence (Chapters IV and IX). Bird diversity was supported by the broad gradients of woody vegetation cover and compositional heterogeneity. Land-use intensification, and hence the loss of woody vegetation cover and homogenization of land covers, would thus negatively affect biodiversity. This was especially evident from predictions on the distribution of the corncrake (Crex crex) in response to potential future land cover homogenization. Here, a moderate reduction of land cover diversity could drastically reduce the extent of corncrake habitat. Further results showed that the brown bear (Ursus arctos) would mainly be affected by land-use change through the fragmentation of large forest blocks, especially if land-use change would reduce habitat connectivity to the presumed source population in the Carpathian Mountains. Moreover, this dissertation revealed that large carnivores (brown bear and wolf, Canis lupus) may have important and often ignored roles in structuring the ecosystem of traditional farming landscapes by limiting herbivores. Wood pastures were found to have a high conservation value. The combination of low-intensity used grasslands with old scattered trees provided important supplementary habitat for different forest species such as woodpeckers and the brown bear. Worryingly, current management of wood pastures differed from traditional techniques in several aspects, which may threaten their persistence in the landscape. The majority of people had a positive perception on human-bear coexistence. The use of traditional sheep herding techniques combined with the tolerance of some shepherds to occasional livestock predation facilitated coexistence in a region where both carnivores and livestock are present. More generally, the genuine links between people and their environment were important drivers of people´s positive views on coexistence. However, perceived failures of top-down managing institutions could potentially erode these links and reduce people´s tolerance towards bears. Through the consideration of two different animal taxa, this dissertation revealed six important system properties facilitating biodiversity conservation in traditional farming landscapes. Similar proportions of the main land-use types (arable land, grassland, and forests) support species richness at the regional scale possible through habitat connectivity and continuous spill-over between land-use types. Heterogeneous landscapes can further support biodiversity through complementation and supplementation of habitat at the landscape scale. Gradients of woody vegetation cover and heterogeneity, supported biodiversity at both local and landscape scales possibly through the provision of a wide range of resources. The heterogeneous character of the landscape is tightly linked to traditional land-use practices, which also maintain specific traditional land-use elements and facilitate human-carnivore coexistence. Top-down limitation of large carnivores on herbivores possibly enhances vegetation growth and tree regeneration. The genuine links between humans and nature support human-bear coexistence, and these links may form the core of people´s values and sustainable use of natural resources.
Tropical forests worldwide support high biodiversity and contribute to the sustenance of local people’s livelihoods. However, the conservation and sustainability of these forests are threatened by land-use changes and a rapidly increasing human population. In this dissertation, I focused on the effects of land-use change on forest biodiversity in the rural landscapes of southwestern Ethiopia, against a backdrop of human population growth. These landscapes are being progressively degraded, encroached and fragmented as a result of different pressures, including the intensification of coffee production, farmland expansion, urbanization and a growing rural population. Understanding the drivers of biodiversity loss and the responses of biodiversity to such pressures is fundamental to direct conservation efforts in these tropical forests.
This dissertation aimed to characterize biodiversity patterns in the moist Afromontane forests of southwestern Ethiopia and to examine how biodiversity patterns are affected by land-use and land-use changes (mediated by coffee management intensity, landscape attributes and housing development) in a context of a rapidly growing rural population. To achieve this goal, I take an interdisciplinary approach where, first, I examined the effects of coffee management intensity on diversity patterns of woody plants and birds, spanning a gradient of site-level disturbance from nearly undisturbed forest interior to highly managed shade coffee forests. Results showed that specialized species of woody plants (forest specialists) and birds (forest specialists, insectivores and frugivores) were affected by coffee management intensity. The richness of forest specialist trees and the richness and/or abundance of insectivores, frugivores and forest specialist birds decrease with increasing levels of disturbance. Second, I investigated the effects of landscape context on woody plants, birds and mammals. Community composition and specialist species of woody plants and birds were sensitive to landscape context, where woody plants responded positively to gradients of edge-interior and birds to gradients of edge-interior and forest cover. Further results showed that a diverse mammal community, with 26 species, occurs at the forest edge of shade coffee forests and that the leopard, an apex predator in the region depended on large areas of natural forest. A closer examination of leopard activity patterns revealed a shift in the diel activity as a response to human disturbance inside the forest, further highlighting the importance of natural undisturbed forests for leopards in the region. Together, these findings demonstrate the value of low managed shade coffee forests for biodiversity, and importantly, emphasize the irreplaceable value of undisturbed natural forests for biodiversity. Third, I investigated the effects of prospective rural population growth (mediated by housing development) on the forest mammal community. Here, population growth was projected to negatively influence several mammal species, including the leopard. Housing development that encroached the forest entailed worse outcomes for biodiversity than a combination of prioritized development in already developed areas and coffee forest protection. Fourth, to understand the motivations behind high human fertility rates in the region, I examined the determinants of women fertility preferences, including their perceptions on social and biophysical stressors affecting local livelihoods such as food insecurity and environmental degradation. Fertility preferences were influenced by underlying social norms and mindsets, a perceived utilitarian value of children and male dominance within the household, and were only marginally affected by perceptions of social and biophysical stressors. Results further indicated a mismatch between the global discourse on the population-environment-food nexus and local perceptions of this issue by women. My findings suggest the need for new deliberative and culturally sensitive approaches that engage with pervasive social norms to slow down population growth.
Overall, this dissertation demonstrates the key value of moist Afromontane forests in southwestern Ethiopia for biodiversity conservation. It indicates the need to promote coffee management practices that reduce forest degradation and highlights that high priority should be given to the conservation of undisturbed natural forests. It also suggests the need to integrate conservation goals with housing development in landscape planning. A promising approach to achieve the above conservation priorities would be the creation of a Biosphere Reserve and to promote the ecological connectivity between the larger forest remnants in the region. Finally, this dissertation demonstrates the importance of placed-based holistic approaches in conservation that consider both proximate and distal drivers of forest biodiversity decline.
Loss of natural and semi-natural habitat due to increasing human land use for agriculture and housing has led to widespread declines in bee pollinator diversity and abundance, which raised global concerns about the stability of pollination services. Bee population dynamics depend on floral resource diversity and availability in the surrounding landscape, and loss of plant biodiversity may thus directly impair the fitness of individual bee species. However, whether and how plant and resource diversity and availability affect foraging patterns, resource intake, resource quantity and nutrient quality and ultimately fitness of generalist social bees remains unclear. In this thesis, we placed hives of the Australian eusocial stingless bee Tetragonula carbonaria (Apidae, Meliponini) in natural habitat (subtropical forests) and two landscapes differently altered by humans (suburban gardens and macadamia plantations), varying in plant species richness, resource abundance and respective habitat patch size. Foraging patterns and resource intake were compared between landscapes in different seasons and colony growth and fitness were monitored over two and a half years. Bee foraging activity, pollen and sugar intake, diversity of collected pollen and resin resources, resource quantity (colony food stores), colony fitness (brood volume, queenand worker reproduction) and colony growth overwhelmingly increased with plant species richness in the surrounding habitat. However, plant species richness and thus bee fitness was highest in gardens, not in natural forests, as bees in gardens benefited from the continuous floral resource availability of both natural and exotic plants across seasons. In contrast, foraging rates and success, forager orientation and consequently colony fitness was largely reduced in plantations. While bees maximized diversity of collected resources, collecting more diverse resources did however not increase resource functionality and nutritional quality, which appeared to be primarily driven by the surrounding plant community in our study. Conversely, individual worker fitness (body fat and size) was not affected by available resource diversity and abundance, showing that colonies seem not to increase the nutritional investment in single workers, but in overall worker population size. This thesis consequently revealed the outstanding role of plant biodiversity as a key driver of (social) bee fitness by providing more foraging resources, even when only small but florally diverse patches are available.
Tropical ecosystems are critical for biodiversity conservation and local people’s livelihood sustenance. However, these ecosystems are under high pressure from land-use and land cover (LULC) change, which is further projected to intensify and increase rapidly, thereby affecting biodiversity and the provisioning of vital ecosystem services (ES). It is thus important to understand how LULC might change in the future and how such changes could affect biodiversity and ES provisioning in a given landscape of tropical ecosystems. Scenario planning has become an increasingly popular tool and technique to produce narrative scenarios of the future landscape change. Thus, quantifying changes under different land-use scenarios could be a means to elucidate the synergies and trade-offs within the scenarios. In this dissertation, I examine the future of biodiversity and ES provisioning for different plausible land-use scenarios in southwestern Ethiopia.
First, I translated four future plausible narrative social-ecological land-use scenarios (namely, ‘Gain over grain’, ‘Coffee and conservation’, ‘Mining green gold’ and ‘Food first’) developed for southwestern Ethiopia by participatory scenario planning into spatially explicit LULC scenario maps. Results showed distinct LULC changes under each scenario. For instance, forest cover under the ‘Gain over grain’ and ‘Coffee and conservation’ scenarios remained similar to the current landscape covering about half of the landscape, in contrast it decreased by 27% and by about 18% under ‘Mining green gold’ and ‘Food first’ scenarios, respectively. Coffee plantation and arable land for cereal crop production covered about half of the landscape under ‘Mining green gold’ and ‘Food first’ scenarios, respectively. Second, I investigated the impact of these land-use scenarios on biodiversity by specifically modelling woody plant species richness in farmland and forest. Both indicators of human disturbance and environmental conditions were used. The results indicated that the ‘Mining green gold’ and ‘Food first’ scenarios would result in strong losses of biodiversity, whereas the ‘Gain over grain’ scenario largely maintained biodiversity relative to the baseline. Only the ‘Coffee and conservation’ scenario showed positive changes for biodiversity that are likely viable in the long run. Third, I also investigated the effect of these land-use scenarios on woody plant-based ES provisioning by combining woody plant species with household surveys on how woody plants were used by the local community. I modelled and predicted the current and future availability of woody plant-based ES under the four scenarios of landscape change. The results showed that land-use scenarios with intensified food or cash crop cultivation would lead to the contraction of woody-plant based ES from farmland to forest patches, implying increased pressure on remaining forest patches. In such a context, attempts to ‘spare’ forest patches from local people will likely be ineffective or alternatively, will have serious negative consequences for local livelihoods. I further modelled and mapped the spatial distribution of six ES: two regulating services (erosion control and carbon storage), three provisioning services (coffee production, crop production and livestock feed) and a supporting service (woody plant richness) for the current landscape and the four land-use scenarios. Results showed smallholder farmers specializing on cash crops (‘Gain over grain’ scenario) would likely cause little change to ES generation, but major losses in ES would result from intensification scenarios (‘Mining green gold’ and ‘Food first’). Finally, the ‘Coffee and conservation’ scenario appears to be the most sustainable scenario because it would secure diverse ES in the long run. This study provides methodological and empirical contributions to the developing fields of scenario planning, social-ecological systems analysis, conservation and landscape change sciences. In addition, it has practical implications for local stakeholders and decision-makers, who can draw on findings for a better-informed land-use management.
Overall, the findings of this dissertation showed the importance of integrating future land-use mapping with participatory, narrative-based scenarios to assess the social-ecological outcomes of alternative futures. The spatially explicit maps of LULC change, biodiversity and ES (at different scales) could be used as a valuable input to support stakeholders and decision-makers to weigh the advantages and disadvantages of different development trajectories on ecosystems and human well-being and to avoid or minimize future undesirable consequences. To this end, apart from the benefits of coffee production under ‘Mining green gold’ and crop production under ‘Food first’ scenarios, the findings under these scenarios of large-scale agricultural intensification point to a potentially high loss of biodiversity and ES. These two scenarios could have a negative long-term impact on ecosystems and human well-being. Finally, the ‘Coffee and conservation’ scenario, which involves the creation of a new biosphere reserve, appears to be the most sustainable scenario. This scenario could result in a sustainably managed, diversified landscape which could make major contributions to biodiversity conservation and human well-being in the region and beyond.
Diese Arbeit stellt eine Pionierarbeit zum Thema Keyline Design als ganzheitliches Gestaltungskonzept für landwirtschaftliche Betriebe im deutschsprachigen Raum dar und ist aus der Zusammenarbeit mit Akteuren der Gemeinschaft Schloss Tempelhof in Süddeutschland entstanden. Keyline Design hat zum Ziel, durch systematische Planung von landwirtschaftlicher Flächennutzung und Tiefenlockerung in einem topographieabhängigen Kultivierungsmuster, die Bodenfruchtbarkeit zu steigern sowie Wasserfluss auf Landschaften kontrolliert zu nutzen und gleichmäßig zu verteilen. Vor dem Hintergrund von Bodendegradation durch landwirtschaftliche Praktiken und sich verändernde klimatische Bedingungen, stellen divers gestaltete Landschaften eine wichtige Anpassungsstrategie zum Schutz gegen Extremwetterereignisse dar. Keyline Design hat bisher innerhalb dieses Diskurses in Zentral- und Nordeuropa wenig Beachtung erfahren. Für die transdisziplinäre Zusammenarbeit wurde innerhalb dieser Arbeit eine Vorgehensweise zur Erstellung eines Keyline Entwicklungsszenarios entwickelt: Mithilfe eines transdisziplinären Arbeitstreffens und einem online Fragebogen wurden die Ziele und Entwicklungswünsche der 140 Personen umfassenden Gemeinschaft Schloss Tempelhof erfasst und auf Basis eines Keyline Kultivierungsmusters ein Entwicklungsszenario für die landwirtschaftliche Flächennutzung erstellt. Keyline Design wurde als Planungskonzept für die topographieabhängige Integration von Agroforstsystemen, wie Pufferzonen, Waldweiden und Alley Cropping, sowie für die Platzierung von Wasserkörpern genutzt. Die Ergebnisse des Entwicklungsszenarios zeigen, dass das erarbeitete Kultivierungsmuster von der Topographie abhängig ist, die Ausgestaltung des Szenarios jedoch vor allem vom Kontext der Akteure.
Wood-pastures have been present in Europe for thousands of years. This form of grazed landscape, combining herbaceous vegetation with trees and shrubs, has often co-evolved with its human users into complex social-ecological systems (SES). Wood-pastures are associated with high cultural and biodiversity values and are an example of the sustainable use of resources. However, due to their often relatively labour-intensive management and low productivity, large areas of wood-pastures have been lost over the last century. The loss of these areas means not only the loss of biodiversity on both local and landscape scales, but also the loss of traditional farming and cultural heritage in some regions. Across the European Union, wood-pastures are facing different problems and are embedded in different social systems and ecological environments. Yet they are all affected by global change and common European policies. To understand the challenges for wood-pastures in a changing world, a holistic approach combining different disciplines is needed. This dissertation therefore is analyzing wood-pastures across Europe as a Social-ecological System, combining ecology and social science with the aim to identify the barriers and drivers for wood-pastures persistence into the future.