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Publication

Landscape stewardship in under-use contexts : a transdisciplinary social-ecological analysis of common pastures in the Black Forest Biosphere Reserve

(2024) Brossette, Florian; Bieling, Claudia

The common pastures of the UNESCO Black Forest Biosphere Reserve are the ecological hotspot, identification element and key feature of the cultural landscape in the southern Black Forest, Germany. In the second half of the 20th century, the Black Forest has witnessed an ongoing decline in grazing activity and pastureland, so that diverse actors of civil society, politics and science are concerned with how the social-ecological importance of the Black Forest common pastures can be sustained. Declining land use and the abandonment of traditional land-use practices constitute an important threat to cultural landscapes not only in the Black Forest, but also in many places all across the world. However, sustainability sciences have been mostly concerned with questions of overexploitation so far. Research addressing the social and ecological drivers of under use, and their interplay, is still lacking. Recent studies on under-used cultural landscapes offer insights into governance arrangements. Still, the consideration of relationships between people and their environment, a key approach to analyse and lever sustainability, are yet missing in the context of under use. Against this background, this cumulative dissertation draws on common pastures in the Black Forest Biosphere Reserve as a case study to develop social-ecological perspectives for cultural landscapes threatened by under use. The three research articles that form the basis for this dissertation explore the diverse interactions between humans and their environment to ask the question what changes in terms of adaptations and transformations are required to sustain the common pastures. The dissertation asks how conceptual insights on organizational design of common pastures, adaptive governance and social-ecological resilience help to grasp and to advance farmers’ perspectives on future pathways for grassland which is endangered by under use. Furthermore, the dissertation poses the question on how resonance theory, a qualitative analysis of relationships between self and world, contributes to a better understanding of the different types of relationships that characterise action in pursuit of landscape sustainability, referred to by the term landscape stewardship. This dissertation follows a transdisciplinary research approach, in the sense that practitioners motivated this research, provided data and validated the findings. The author’s practical experience as staff of the Black Forest Biosphere Reserve links research, practice and landscape stewardship. The dissertation is rooted in social-ecological systems thinking. The notion of social-ecological systems understands common pastures in terms of interlinked social and ecological elements and processes. The research articles make use of the concepts of Ostrom Design Principles, Social-Ecological Systems Framework, social-ecological Resilience Principles, relational approaches in social-ecological thinking and Resonance Theory. Resonance characterizes the occurrence of meaningful relational encounters that potentially transform self-world relationships. The notion of landscape stewardship refers to the diversity of meanings that motivate action in pursuit of landscape sustainability. Landscape stewardship thus serves as a frame to connect the different concepts and research articles of the present work. Rooted in empirical social research, this dissertation adopts a qualitative methodology but includes quantitative data to illustrate and support qualitative findings. Given the rich conceptual foundation and transdisciplinary approach, the results of this dissertation allow for both conceptual advancements and practical recommendations. The results of the research articles show that place-based practical perspectives and social-ecological concepts reinforce one another. Practitioners’ central assertion that diverse small-scale farming initiatives are required to sustain common pastures illustrate and substantiate the conceptual groundings of adaptive governance, resilience, and Resonance Theory. Concerning adaptive governance, this research finds that a central element of organizational design in the under-use context of the Black Forest common pastures is to include all actors that take advantage of the cultural landscape. This implies to motivate and incentivize diverse actor groups, such as tourism and local population, to contribute to landscape stewardship in a way that corresponds to their benefits. Relational and resilience arguments emphasize the importance of multiple and diverse structures in grassland farming. This implies that specific support to match the needs and challenges of initiatives such as landcare groups, common pasture organizations or small-scale farming is required. The resilience perspective adds to this in highlighting that polycentric governance should find stronger application to encourage reciprocal learning and maintain the social-ecological diversity connected to common pastures. The introduction of Resonance Theory into social-ecological research provides important contributions to the debate on sustainability transformations. By emphasizing the uncontrollable and unpredictable character of meaningful relationships, Resonance Theory shifts the practical and conceptual focus on agency towards the quality of relationships. The axes of resonance provide a framework to analyse different types of relationships between self and world that are present in initiatives of landscape stewardship. From the perspective of Resonance Theory, adaptive governance should be directed towards enabling or favouring the emergence of meaningful relationships between people, livestock and the landscape. The practical and conceptual recommendations to sustain common pastures call for changes in terms of adaptations and transformations. The importance and consequences of these key changes, such as improved commercialization of pasture products, the integration of local people into landscape stewardship, or to fit the administrative frameworks and support schemes to the social-ecological reality of common pastures, depend on the social-ecological perspective of analysis. As grassland farmers or public administration have their specific view on common pastures, the anticipated effects of and the required commitment to these changes differ, so that they may appear as adaptations to one group, while constituting transformations to another. To conclude, this dissertation shows that the application of different social-ecological concepts to rich contextual data advances both conceptual and practical understandings of under use and the interconnectedness of humans and their environment. In bringing together science and practice, biosphere reserves are particularly suited for transdisciplinary approaches. For supporting landscape stewardship, the Black Forest Biosphere Reserve will need to include more actors benefiting from common pastures to contribute to their sustenance. Moreover, it is important to create conditions that enable meaningful relationships and resonance in landscape stewardship. There is a need for further place-based research in under-use contexts to provide more knowledge of the organizational and relational aspects that characterize under use. To benefit from the full potential of the resonance perspective, it is necessary to show how contextual, institutional and cultural conditions that foster or inhibit resonance can be accounted for in social-ecological research.

Publication

Quality impact of nitrogen in wheat grain properties and protein development for higher baking quality

(2022) Rekowski, Azin; Zörb, Christian

Storage protein concentration and composition influence the baking quality of wheat. Traditionally, baking quality is correlated with the total protein concentration in flour. However, despite similar protein concentrations, the baking qualities of different cultivars can vary, and the variances may be related to differences in the storage protein composition (Zörb et al., 2018). Though both protein concentration and composition are affected by fertilization management (especially nitrogen) and water availability, it is not certain whether compositional changes will suffice to enhance the quality of final products. Additionally, there is a high risk for the environment, associated with nitrogen losses in wheat production. To increase nitrogen efficiency, minimize nitrogen losses and optimize the baking quality, it is crucial to improve nitrogen fertilizer management. To address the question whether nitrogen and water management induce changes in protein composition which result in altered baking qualities, several investigations were conducted in the present work. Total protein was extracted from wheat flour and SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis) was used to detect proteins sub-fractions. To assess baking quality, the specific volume, freshness retention as well as the hardness of the bread were evaluated. In chapter two, as part of a pot experiment, two different levels of late nitrogen fertilizer were tested using two winter wheat cultivars of different quality classes (Discus and Rumor). Both cultivars produced more grain yield and total protein concentration as a result of late nitrogen supply. However, bread volume was only increased in Discus, possibly related to the greater changes in total gluten concentration and protein composition including HMW-GS and ω-gliadins. However, an increase of late nitrogen level did not further improve baking quality. Compared to Discus, an addition of late nitrogen did not result in significant changes in the protein composition of Rumor. Collectively these results indicate that late nitrogen management strategies are practical but need to be adjusted depending on the cultivar used. Chapter three describes a field experiment where three different nitrogen forms were used ((i)ammonium nitrate, (ii) urea with 46% total N, (iii) urea as before amended with urease inhibitor N-(2-nitro-phenyl) phosphoric triamide (2-NPT) and (iv) control (no nitrogen addition)). While no significant/only a slight effect was observed for urea alone, ammonium nitrate and urea plus urease inhibitor similarly increased total grain protein concentrations. Although both fertilizers boosted the levels of ω-gliadins and HMW-GS among the storage protein fractions, the influence was more pronounced in the ammonium nitrate application. In comparison to the urea treatment, the combination of urea plus urease inhibitor significantly influenced protein composition and generated higher specific baking volumes and the best fresh-keeping characteristics. Due to the strong enhancement in NUE and baking quality obtained with the urea plus urease inhibitor application, accompanied by reduced nitrogen losses and easy handling, this treatment could be considered as a substitute for urea alone or ammonium nitrate. Chapter four describes a field study conducted in Iran with different German (Impression, Discus, Rumor, Hybery) and Iranian (Alvand, Mihan) genotypes representing diverse quality classes and grain protein levels. Two different levels of water stress were applied during anthesis and grain filling period. Overall, no significant changes in total protein concentrations were recorded. In addition, the concentrations of different protein fractions were unchanged in five out of the six genotypes. However, German genotypes exhibited an increase in HMW-GS under severe drought conditions, and an increased severity of drought stress amplified the percentage of ω-gliadins in all genotypes. Even though drought stress did not alter the concentrations of the HMW-GS sub-fraction in Iranian genotypes, a high specific bread volume was still observed, most likely related to an increase in ω-gliadins. All in all, the protein composition should be considered in addition to yield and total grain protein concentration when developing new wheat varieties for challenging climatic conditions. In summary, late nitrogen and urea application, along with the addition of urease inhibitors, can enhance the gliadin and glutenin content and improve the baking quality. In addition, it may be possible to develop wheat genotypes with optimal baking properties by paying attention to the protein composition when drought stress exists. Although genetically determined subunits of the gluten fractions are known to be associated with bread-making quality, the studies presented here indicate that additional factors, such as the levels of nitrogen supply or water limitation, affect the composition of grain protein fractions and can be positively correlated with baking quality. Therefore, total grain protein concentration alone is not a reliable indicator of grain quality. Additionally, several individual proteins were altered by different management practices. Consequently, these proteins can have great effects on the quality of breads, so further studies should evaluate whether those individual proteins directly correlate with bread baking quality.

Publication

Downscaling of ECMWF SEAS5 seasonal forecasts over the Horn of Africa using the WRF model

(2023) Mori, Paolo; Wulfmeyer, Volker

Several studies have shown the potential for downscaling seasonal forecasts on a convection-permitting (CP) scale using limited-area models (LAMs). In most cases, such experiments initial and boundary conditions are derived from atmospheric and surface analyses, which use measurements to constrain the model evolution. For operational use, the boundary conditions are derived from global seasonal forecasts, which only evolve depending on numerical models. This difference will affect the downscaling process and potentially the results’ skill. In this work, the SEAS5 seasonal forecasts are downscaled to address this gap in our understanding. Specifically, the research questions are: What advantages of a CP simulation are present when dynamically downscaling ensemble seasonal forecasts with a LAM? How do boundary conditions and physics parametrization perturbations affect a LAM ensemble in terms of spread and reliability? What perturbations produce more ensemble spread for temperature and precipitation? The study area chosen is the Horn of Africa. The effects of climate change have become much more apparent in East Africa in the last decade: the rainy season has repeatedly failed, which has led to extreme droughts. Therefore, any improvements in this regions seasonal forecasts can help to develop adaptation strategies further. In addition, areas with complex topography benefit the most from increased spatial resolution, and the global models skill is higher in the tropics and subtropics than in middle latitudes. Thus, it is likely that downscaling can extract helpful information in this region. Four global ECWMF SEAS5 ensemble members were dynamically downscaled for summer 2018 over the Horn of Africa using the Weather Research and Forecasting (WRF) model to investigate the potential of a seasonal forecast on convection-permitting resolution (3 km). A total of 16 WRF ensemble members with varied initial and boundary conditions and different physical schemes were used to evaluate the impact of the downscaling. The analysis assessed the effects of perturbations on surface temperature and rainfall in terms of bias, spatial distribution, probability of extreme events, rain belt movements, and ensemble spread. The main findings of this work are the following: the WRF simulations reproduced the spatial distribution of the 2m temperature and precipitation patterns. The bias present in SEAS5 was transferred to the limited-area model, and the signal is even intensified in some areas. For example, while the four SEAS5 members deviated only by +0.2°C on average compared to the ECMWF analyses, the WRF ensemble bias was +1.1°C. The WRF ensemble simulated an average of 264 mm of rain, compared to 248 mm for SEAS5 and 236 mm for the GPM-IMERG satellite product. The convection-permitting resolution reproduced the precipitation probability density function slightly better than the global model and simulated extreme precipitation events missing in SEAS5. However, it overestimated their frequency compared to observations. In addition, WRF can reproduce the daily precipitation cycle well: the peak times coincide with measurements, showing an accurate representation of convection initiation in the area and the potential of dynamical downscaling at convection-permitting resolution. The boundary conditions limited the movement of the rain belt associated with the inter-tropical convergence zone in the downscaling. For example, the north extension of the tropical rain belt decreased in both models by 2 degrees of latitude compared to GPM-IMERG, and the global model timing strongly influenced the movements of the rain belt in WRF. The SEAS5 has shown moderate skill in precipitation forecasts in Ethiopia. Still, a better understanding of the yearly variability of the rain belt position is necessary, as it is a crucial factor in high-resolution downscaling in the region. The downscaling increased the ensemble spread for precipitation by an average of 60%, partially correcting the SEAS5 under-dispersion. In the Ethiopian highlands, perturbed boundary conditions are primarily responsible for the WRF ensemble spread. Their effect is often 50% greater than the variability resulting from the various physics parameterizations. The results show that boundary-conditions perturbations are necessary to generate adequate ensemble dispersion in a limited-area model with complex topography. The analysis partially confirmed the potential to improve seasonal forecasts through downscaling, especially concerning convective precipitation timing and heavy rainfall events. Some advantages of downscaling atmospheric analysis are lost due to the inaccuracies in the forcing derived from SEAS5 and model bias. It also highlights the necessity of further research on physics schemes or combinations suitable to convection-permitting resolutions.

Publication

Energiebedarf von Traktoren und ausgewählten Anbaugeräten in der Außenwirtschaft landwirtschaftlicher Betriebe

(2024) Schwehn, Julian; Böttinger, Stefan

Vor dem Hintergrund des Klimawandels und hoher Ressourcenpreise ist der umsichtige Einsatz der zur Verfügung stehenden Energieträger von besonderer Bedeutung. Um die Folgen anthropogener Treibhausgasemissionen auf das Klima zu minimieren, sehen legislative Vorgaben in Europa und Deutschland ambitionierte Reduktionsziele für einzelne Sektoren wie die Landwirtschaft vor. Die heterogene Agrarstruktur erfordert standortgerechte Produktions und Arbeitsverfahren, was zu einer großen Vielfalt an eingesetzten Maschinen und Anbaugeräten führt. Neben der Untersuchung von Einsparpotentialen einzelner Fahrzeugkomponenten bieten landwirtschaftliche Verfahrensketten mögliche weitere Einsparungen. Die Erforschung dieser prozessualen Potentiale macht eine detaillierte Kenntnis der eingesetzten Maschinen und Anbaugeräte aus energetischer Sicht notwendig. Um die Einsparpotentiale innerhalb der Prozesse sowie der eingesetzten Technologien quantifizieren zu können, wird in der vorliegenden Arbeit der Energiebedarf von Traktoren und ausgewählten Anbaugeräten ermittelt. Dazu wird nach der Einführung einzelner Maschinen und Anbaugeräte eine Metastudie verschiedener Testverfahren und Literaturquellen durchgeführt, um die vorhandene Datenbasis zu bewerten und Datenlücken aufzuzeigen. Soweit es die Datenbasis zulässt, werden der aktuelle Stand und eine Entwicklung seit 1990 dargestellt, um die bereits erzielten Einsparungen aufzuzeigen. Darüber hinaus erfolgt ein Vergleich sowie eine Evaluierung bestehender Modellansätze zur Berechnung des Energiebedarfs einzelner Maschinen und Anbaugeräte. Aus der Kenntnis vorhandener Datenlücken sowie der Güte aktueller Parametersätze können systematische Feldversuche für weiterführende Arbeiten abgeleitet werden.

Publication

Nutritional and hemoglobin status in relation to dietary micronutrient intake: studies in female and male small-scale farmers from Lindi region, Tanzania, and Gurué district, Mozambique

(2024) Eleraky, Laila; Frank, Jan

Inadequate consumption of micronutrient-dense and protein-rich foods, such as vegetables, legumes and meat, are important contributing causes for malnutrition, anemia and micronutrient deficiencies in rural communities of Tanzania and Mozambique. The increasing public health concern of the malnutrition form of overweight has repeatedly been reported in urban as well as rural areas of Sub-Sahara Africa and may have already reached farmers in Tanzania and Mozambique. Nutritional status is assessed by anthropometry, dietary intake and hemoglobin. Compared to the often-used body mass index (BMI) and traditional 24-hour recall, the mid-upper-arm-circumference (MUAC), as well as a food group-based algorithm (CIMI) can be suitable additional assessment tools, especially in resource poor environments. Cross-sectional studies within the framework of the Vegi-Leg project were conducted to assess the nutritional status (anthropometrics and hemoglobin measurements), and the dietary behaviours (Household Dietary Diversity Scores (HDDS), Food Frequency Questionnaires (FFQ) and 24-hour recalls) of female and male farmers from rural areas of Tanzania and Mozambique. Data were analysed by region, sex, age, partly season (Tanzania)and correlates. Additional data from similar projects, namely Scale-N and Trans-SEC in rural villages of Tanzania were included in MUAC and CIMI analysis. MUAC as an additional and easy-to-handle anthropometric marker for underweight, as well as overweight was evaluated using data from Vegi-Leg and Scale-N surveys. MUAC cut-offs, calculated via BMI cut-offs and multiple linear regression (MLR), compared to those selected by highest Youden’s index (YI) value, were assessed. The CIMI algorithm included 23 food groups and was tested in comparison to NutriSurvey (detailed quantitative 24 hour recalls) with data from Scale-N and Trans-SEC.A total of 1526 farmers from the Vegi-Leg project (669 from Tanzania, 857 from Mozambique) were studied, of whom 19% were overweight and 35% were anemic. The study showed an overall higher prevalence of overweight (19%) than underweight (10%), mainly due to the high prevalence of overweight female farmers (up to 35%) in southern Tanzania. The highest prevalence of overweight and anemia, at 35% and 48%, was observed in Tanzanian and Mozambican women, respectively. Regarding HDDS and FFQ data, pigeon pea farmers in Lindi and Gurué reported high consumption frequencies of cereals, legumes, vegetables and oil, while meat, fish and eggs were only consumed rarely. Overall, only a small proportion of enrolled women and men reached the recommended daily dietary intake of vitamin A (10%), iron (51%) and zinc (44%) according to the 24-hour recalls. Multiple regression models revealed that dark green leafy vegetables (DGLVs) highly predicted vitamin A intake, whereas legumes in Tanzania and starchy plants in Mozambique were the dominant sources of vitamin A. Cereals contributed to over half of the iron and the zinc intake in both countries. Seasonal analysis revealed high fluctuations for the consumption frequency of food items from the food groups ‘legumes and pulses’, ‘green leafy vegetables’, ‘other vegetables’ and ‘fruits’, including tomatoes, pigeon peas, mangoes and oranges. The results from Lindi Tanzania revealed, that in seasons, when the availability of food groups like fruits, legumes or vegetables was low, the consumption frequency decreased significantly. BMI, which correlated positively and strongly with MUAC, was higher in Tanzania than in Mozambique and higher among female than male farmers, and decreased significantly from the age of 65 years. MUAC cut-offs of <24 cm and ≥30.5 cm, calculated by multiple linear regression, detected 55% of farmers being underweight and 74% being overweight, with a specificity of 96%; the higher cut-off <25 cm and lower cut-off ≥29 cm, each selected according to Youden’s Index, consequently detected more underweight (80%) and overweight farmers (91%), but on the basis of a lower specificity (87–88%). The results of the algorithm CIMI and NutriSurvey were similar with regard to the average intake and range of data distribution. The correlation coefficients of NutriSurvey and CIMI with regards to energy (0.931), protein (0.898), iron (0.775) and zinc (0.838) intake, supported the matching of both calculations. An increased consumption of micronutrient rich DGLVs and legumes, while reducing the high amounts of refined sugar, maize and polished rice, is suggested to counteract the high prevalence of anemia and overweight among smallholder farmers in rural Tanzania and Mozambique. MUAC cut-offs to detect malnutrition whether defined via linear regression or Youden’s Index, proved to be easy-to-use tools for large-scale rural screenings of both underweight and overweight. The food group based CIMI algorithm is a valid instrument that calculates energy and nutrient intake in agreement with the preferred nutrition software NutriSurvey.