Institut für Landschafts- und Pflanzenökologie

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Agrivoltaics: The environmental impacts of combining food crop cultivation and solar energy generation
(2023) Wagner, Moritz; Lask, Jan; Kiesel, Andreas; Lewandowski, Iris; Weselek, Axel; Högy, Petra; Trommsdorff, Max; Schnaiker, Marc-André; Bauerle, Andrea
The demand for food and renewable energy is increasing significantly, whereas the availability of land for agricultural use is declining. Agrivoltaic systems (AVS), which combine agricultural production with solar energy generation on the same area, are a promising opportunity with the potential to satisfy this demand while avoiding land-use conflicts. In the current study, a Consequential Life-Cycle Assessment (CLCA) was conducted to holistically assess the environmental consequences arising from a shift from single-use agriculture to AVS in Germany. The results of the study show that the environmental consequences of the installation of overhead AVS on agricultural land are positive and reduce the impacts in 15 of the 16 analysed impact categories especially for climate change, eutrophication and fossil resource use, as well as in the single score assessment, mainly due to the substitution of the marginal energy mix. It was demonstrated that, under certain conditions, AVS can contribute to the extension of renewable energy production resources without reducing food production resources. These include maintaining the agricultural yields underneath the photovoltaic (PV) modules, seeking synergies between solar energy generation and crop production and minimising the loss of good agricultural land.
Editorial: Seed behavior in response to extreme environments
(2023) Zhu, Jinlei; Wang, Lei
Agrivoltaics mitigate drought effects in winter wheat
(2023) Pataczek, Lisa; Weselek, Axel; Bauerle, Andrea; Högy, Petra; Lewandowski, Iris; Zikeli, Sabine; Schweiger, Andreas
Climate change is expected to decrease water availability in many agricultural production areas around the globe. At the same time renewable energy concepts such as agrivoltaics (AV) are necessary to manage the energy transition. Several studies showed that evapotranspiration can be reduced in AV systems, resulting in increased water availability for crops. However, effects on crop performance and productivity remain unclear to date. Carbon‐13 isotopic composition (δ13C and discrimination against carbon‐13) can be used as a proxy for the effects of water availability on plant performance, integrating crop responses over the entire growing season. The aim of this study was to assess these effects via carbon isotopic composition in grains, as well as grain yield of winter wheat in an AV system in southwest Germany. Crops were cultivated over four seasons from 2016–2020 in the AV system and on an unshaded adjacent reference (REF) site. Across all seasons, average grain yield did not significantly differ between AV and REF (4.7 vs 5.2 t ha−1), with higher interannual yield stability in the AV system. However, δ13C as well as carbon‐13 isotope discrimination differed significantly across the seasons by 1‰ (AV: −29.0‰ vs REF: −28.0‰ and AV: 21.6‰ vs REF: 20.6‰) between the AV system and the REF site. These drought mitigation effects as indicated by the results of this study will become crucial for the resilience of agricultural production in the near future when drought events will become significantly more frequent and severe.
Functional traits shape plant–plant interactions and recruitment in a hotspot of woody plant diversity
(2023) Cooksley, Huw; Dreyling, Lukas; Esler, Karen J.; Griebenow, Stian; Neumann, Günter; Valentine, Alex; Schleuning, Matthias; Schurr, Frank M.
Understanding and predicting recruitment in species‐rich plant communities requires identifying functional determinants of both density‐independent performance and interactions. In a common‐garden field experiment with 25 species of the woody plant genus Protea, we varied the initial spatial and taxonomic arrangement of seedlings and followed their survival and growth during recruitment. Neighbourhood models quantified how six key functional traits affect density‐independent performance, interaction effects and responses. Trait‐based neighbourhood models accurately predicted individual survival and growth from the initial spatial and functional composition of species‐rich experimental communities. Functional variation among species caused substantial variation in density‐independent survival and growth that was not correlated with interaction effects and responses. Interactions were spatially restricted but had important, predominantly competitive, effects on recruitment. Traits increasing the acquisition of limiting resources (water for survival and soil P for growth) mediated trade‐offs between interaction effects and responses. Moreover, resprouting species had higher survival but reduced growth, likely reinforcing the survival–growth trade‐off in adult plants. Resource acquisition of juvenile plants shapes Protea community dynamics with acquisitive species with strong competitive effects suffering more from competition. Together with functional determinants of density‐independent performance, this makes recruitment remarkably predictable, which is critical for efficient restoration and near‐term ecological forecasts of species‐rich communities.
The need to decipher plant drought stress along the soil-plant-atmosphere continuum
(2023) Schweiger, Andreas H.; Zimmermann, Telse; Poll, Christian; Marhan, Sven; Leyrer, Vinzent; Berauer, Bernd J.
Lacking comparability among rainfall manipulation studies is still a major limiting factor for generalizations in ecological climate change impact research. A common framework for studying ecological drought effects is urgently needed to foster advances in ecological understanding the effects of drought. In this study, we argue, that the soil–plant–atmosphere‐continuum (SPAC), describing the flow of water from the soil through the plant to the atmosphere, can serve as a holistic concept of drought in rainfall manipulation experiments which allows for the reconciliation experimental drought ecology. Using experimental data, we show that investigations of leaf water potential in combination with edaphic and atmospheric drought – as the three main components of the SPAC – are key to understand the effect of drought on plants. Based on a systematic literature survey, we show that especially plant and atmospheric based drought quantifications are strongly underrepresented and integrative assessments of all three components are almost absent in current experimental literature. Based on our observations we argue, that studying dynamics of plant water status in the framework of the SPAC can foster comparability of different studies conducted in different ecosystems and with different plant species and can facilitate extrapolation to other systems, species or future climates.
Alien plant fitness is limited by functional trade‐offs rather than a long‐term increase in competitive effects of native communities
(2023) Brendel, Marco R.; Schurr, Frank M.; Sheppard, Christine S.
Alien plants experience novel abiotic conditions and interactions with native communities in the introduced area. Intra‐ and interspecific selection on functional traits in the new environment may lead to increased population growth with time since introduction (residence time). However, selection regimes might differ depending on the invaded habitat. Additionally, in high‐competition habitats, a build‐up of biotic resistance of native species due to accumulation of eco‐evolutionary experience to aliens over time may limit invasion success. We tested if the effect of functional traits and the population dynamics of aliens depends on interspecific competition with native plant communities. We conducted a multi‐species experiment with 40 annual Asteraceae that differ in residence time in Germany. We followed their population growth in monocultures and in interspecific competition with an experienced native community (varying co‐existence times between focals and community). To more robustly test our findings, we used a naïve community that never co‐existed with the focals. We found that high seed mass decreased population growth in monocultures but tended to increase population growth under high interspecific competition. We found no evidence for a build‐up of competition‐mediated biotic resistance by the experienced community over time. Instead, population growth of the focal species was similarly inhibited by the experienced and naïve community. By comparing the effect of experienced and naïve communities on population dynamics over 2 years across a large set of species with a high variation in functional traits and residence time, this study advances the understanding of the long‐term dynamics of plant invasions. In our study system, population growth of alien species was not limited by an increase of competitive effects by native communities (one aspect of biotic resistance) over time. Instead, invasion success of alien plants may be limited because initial spread in low‐competition habitats requires different traits than establishment in high‐competition habitats.
The role of maternal environment and dispersal ability in plants' transgenerational plasticity
(2023) Lukić, Nataša; Zhu, Jinlei; Schurr, Frank M.; Walter, Julia
Transgenerational effects enable the transmission of environmental cues from parents to offspring. Adaptive maternal effects are expected to evolve if the maternal (or parental) environment contains information about the environment experienced by offspring. This correlation between maternal and offspring environments should be strongest in plant species with reduced dispersal ability. However, studies relating dispersal ability to the strength of maternal effects are rare. This study aimed to explore whether and how the dispersal distance of species and individuals affects offspring plant performance. Using seven common European plant species, we conducted a multi‐year common garden experiment exposing maternal plants to three different water conditions (mesic, drought and waterlogging). At the end of the season in the first year, seed heads were collected from the lower and upper parts of each mother plant and used for dispersal distance calculation. Offspring coming from the maternal lower and upper parts were exposed to the same water treatments as mothers. Contrasting our hypothesis, we found that maternal water experience and species' dispersal abilities did not influence offspring performance (plant aboveground, belowground, reproductive and dead biomass). We did not detect maternal effects, meaning that offspring plants with the same water conditions as their mothers had the same fitness as offspring with different water conditions. However, opposite to our expectations, the longer dispersal distance of individual seeds ensured a stronger maternal effect when exposed to the same water stress as their mothers. Consequently, a stressful environment would select for long‐distance dispersal.
Density dependence of seed dispersal and fecundity profoundly alters the spread dynamics of plant populations
(2023) Zhu, Jinlei; Lukić, Nataša; Pagel, Jörn; Schurr, Frank M.
Plant population spread has fundamental ecological and evolutionary importance. Both determinants of plant population spread, fecundity and dispersal, can be density‐dependent, which should cause feedback between population densities and spread dynamics. Yet it is poorly understood how density‐dependence affects key characteristics of spread: spread rate at which the location of the furthest forward individual moves, edge depth (the geographical area over which individuals contribute to spread) and population continuity (occupancy of the spreading population). We present a general modelling framework for analysing the effects of density‐dependent fecundity and dispersal on population spread and parameterize this framework with experimental data from a common‐garden experiment using five wind‐dispersed plant species grown at different densities. Our model shows that density‐dependent fecundity and dispersal strongly affect all three population spread characteristics for both exponential and lognormal dispersal kernels. Spread rate and edge depth are strongly correlated but show weaker correlations with population continuity. Positive density‐dependence of fecundity increases all three spread characteristics. Increasingly positive density‐dependence of dispersal increases spread rate and edge depth but generally decreases population continuity. Density‐dependent fecundity and dispersal are largely additive in their effect on spread characteristics. For population continuity, the joint effects of density‐dependent fecundity and dispersal are somewhat contingent on the dispersal kernel. The common‐garden experiment and the experimentally parameterized mechanistic dispersal model revealed density‐dependent fecundity and dispersal across study species. All study species exhibited negatively density‐dependent fecundity, but they differed qualitatively in the density‐dependence of dispersal distance and probability of long‐distance dispersal. The negative density‐dependence of fecundity and dispersal found for three species reinforced each other in reducing spread rate and edge depth. The positively density‐dependent dispersal found for two species markedly increased spread rate and edge depth. Population continuity was hardly affected by population density in all study species except Crepis sancta in which it was strongly reduced by negatively density‐dependent fecundity. Synthesis. Density‐dependent fecundity and seed dispersal profoundly alter population spread. In particular, positively density‐dependent dispersal should promote the spread and genetic diversity of plant populations migrating under climate change but also complicate the control of invasive species.
The range potential of North American tree species in Europe
(2024) Albrecht, Axel Tim; Heinen, Henry; Koch, Olef; de Avila, Angela Luciana; Hinze, Jonas
European forest ecosystems are projected to change severely under climate change especially due to an anticipated decline in the distribution of major tree species in Europe. Therefore, the adaptation of European forests appears necessary and urgent. While spontaneous adaptation mechanisms bear a large self-guided potential, we focus on quantifying the potential of management-guided mechanisms. Besides other possible tree species groups for adaptation, non-native tree species from North America have a long tradition in Europe, yet their full distribution potential is not completely revealed. We applied an ensemble species distribution model approach to six North American species, using combined occurrence data from the native and naturalized ranges to gain more insights into the species suitability in the introduced area in 2070 (2061–2080) under the emission scenarios RCP 4.5 and 8.5. Our findings support the assumption that there is unreported species potential in the introduced area beyond their current distribution. Next to northeastern range shifts projected for all species, we identified Abies grandis, Liriodendron tulipifera, Quercus rubra, and Robinia pseudoacacia with increasing range potentials in the future. P. ponderosa and P. menziesii var. menziesii are projected to show a steady and decreased range potential under RCP 4.5 and 8.5, respectively.
Nature's contributions to human well‐being under climate change: Evidence from Central and Eastern Madagascar
(2024) Petzold, Jan; Kosanic, Aleksandra; Rakoto Joseph, Felana; Rajaonarivelo Andrianina, Princy; Ranaivosoa‐Toandro, Sitraka Mireille; Andriamihaja, Onintsoa Ravaka; Voahanginirina, Leonnie Marcelline; Thien, Lara; Razanajatovo, Mialy
Anthropogenic climate change has an unprecedented impact on ecosystems and their services, with severe consequences for human well‐being, particularly for the marginalised and vulnerable members of society in the Global South. The well‐being of communities relies not only on material and regulating services ecosystems provide but also on non‐material services. In this paper, we unravel the diverse ways that climate change impacts affect Nature's Contributions to People (NCP) and the well‐being of rural populations in four sites in Madagascar—a biodiversity hotspot but one of the economically poorest countries in the world. We conducted participatory community workshops, mapping and semi‐structured interviews with local residents across social subgroups to understand the mechanisms of climate‐related degradation and the resulting impacts on different dimensions of human well‐being through an NCP lens. We found that non‐material services are generally more often associated with well‐being effects. Climate change degrades material and non‐material services through sea level rise, biodiversity loss, drought, precipitation and temperature variability, with consequences for materials, companionship and labour, food and feed, and physical and psychological experiences. Loss of land and forests is expressed through ecological grief. The outcome of our research provides evidence‐based information to local policymakers, conservation practitioners, and climate change agencies. This information can help improve government efforts toward holistic conservation and climate change adaptation by addressing the impacts on the physical and mental well‐being of the most vulnerable communities. Read the free Plain Language Summary for this article on the Journal blog.
Plant stress memory within and across generations
(2022) Lukić, Nataša; Schurr, Frank
Im Zuge des Klimawandels werden Trockenheit und Staunässe in vielen Teilen der Welt immer häufiger und intensiver auftreten. Diese Stressfaktoren beeinträchtigen das Pflanzenwachstum, indem sie die Photosynthese hemmen und oxidative Zellschäden verursachen. Eine vielversprechende Strategie von Pflanzen, um mit solchen schädlichen Bedingungen fertig zu werden, ist das pflanzliche Stressgedächtnis. Dies ist die Fähigkeit von Pflanzen, frühere Stressinformationen zu speichern, um als Reaktion auf wiederholten Stress in derselben Generation (Gedächtnis innerhalb einer Generation) oder in der nächsten Generation (transgenerationales Gedächtnis) eine Verbesserung der Pflanzenleistung auszulösen. Pflanzen verfügen auch über ein Cross-Stress-Gedächtnis; die Konfrontation mit einer Art von Stress, erhöht die Toleranz gegenüber eine anderen Stressart. Darüber hinaus könnte das Stressgedächtnis von Pflanzen bei Arten und Individuen mit eingeschränkter Ausbreitung stärker ausgeprägt sein, da eine eingeschränkte Ausbreitung die Kongruenz zwischen der Umgebung der Mutter und ihrer Nachkommen vergrößern könnte. Die Mechanismen, die dem Gedächtnis für Trockenheit und Staunässe und dem möglichen Cross-Stress-Gedächtnis innerhalb einzelner Generationen oder bei Nachkommen zugrunde liegen, sind derzeit unklar. Außerdem gibt es nur wenige Studien, die die Stärke des Stressgedächtnisses von Pflanzen untersuchen. In dieser Doktorarbeit stellte ich die Hypothese auf, dass Trockenheit und Staunässe zur Bildung eines Stressgedächtnisses führen, das die Leistung der Pflanzen verbessert und Veränderungen der morphologischen, photosynthetischen und antioxidativen Parameter bei wiederholter Trockenheit innerhalb derselben Generation bewirkt. Um diese Hypothese zu testen, habe ich Alopecurus pratensis über zwei Jahre hinweg wiederholt Staunässe und Trockenheit ausgesetzt. Im dritten Jahr wurden die Pflanzen ann zwei Wochen lang Trockenstress ausgesetzt. Meine Ergebnisse bestätigten die erste Hypothese, dass Pflanzen, die zuvor Trockenheit ausgesetzt waren, nach wiederholtem Trockenstress in derselben Generation weniger Gewebeschäden und einen höheren Rubisco-Gehalt, und Gehalt an antioxidativen Enzymen (POX und SOD) und Chlorophyll b aufwiesen. Gräser weisen ein langfristiges Trockenstressgedächtnis über mehrere Wochen hinweg auf und dies hängt mit dem anti-oxidativen System zusammen. Darüber hinaus stellte ich die Hypothese auf, dass Nachkommen, die Stress erfahren, besser abschneiden, wenn die Mütter zuvor Stress erfahren haben, unabhängig von der Art des Stresses. Um dies zu testen, führte ich ein voll-faktorielles Topfexperiment über zwei xvi Generationen durch, bei dem Mutter- und Nachkommenpflanzen Staunässe und Trockenheit ausgesetzt wurden. Im Einklang mit meiner zweiten Hypothese erhöhte die Erfahrung der Mutter mit Staunässe und Trockenheit bei vier mehrjährigen Arten die Biomasse und die Reproduktionsleistung der Nachkommen, die denselben Stressbedingungen ausgesetzt waren wie ihre Mütter. Dieses transgenerationale Gedächtnis wurde mit Veränderungen im antioxidativen System einer Art in Verbindung gebracht, die oxidative Schäden durch die Hochregulierung von schützenden Enzymen bei den Nachkommen verringerten, die denselben Bedingungen ausgesetzt waren wie ihre Mütter. Allerdings konnte ich in dem Experiment nur eine Erinnerung an die gleiche Belastung, aber keine Erinnerung an eine andere Belastung feststellen (keine Cross-Stress-Toleranz). Schließlich stellte ich die Hypothese auf, dass die Stärke der adaptiven mütterlichen Effekte bei Arten oder einzelnen Samen mit geringerer Fähigkeit zur Samenverbreitung zunimmt. Um die dritte Hypothese zu prüfen, wurden von den unteren und oberen Teilen jeder Mutterpflanze Samenköpfe gesammelt, um die Stärke des transgenerationalen Gedächtnisses zu testen, und für die Berechnung der Ausbreitungsdistanz verwendet. Die Nachkommen der unteren und oberen Teile der Mutterpflanzen wurden denselben Wasserbehandlungen ausgesetzt wie die Mütter. Im dritten Experiment konnten die Mutterpflanzen ihre Nachkommen nicht auf den bevorstehenden Wasserstress vorbereiten. Auch eine mütterliche Stresserfahrung als solche konditionierte die Nachkommen nicht auf andere Arten von Stress. Außerdem zeigten Samen mit einer längeren erwarteten Ausbreitungsdistanz entgegen meinen Erwartungen einen stärkeren mütterlichen Anpassungseffekt, wenn sie demselben Wasserstress ausgesetzt waren wie ihre Mütter. Meine Forschung liefert Beweise für ein Trockenheitsgedächtnis innerhalb von Generationen und über Generationen hinweg und stellt eine Verbindung zu den zugrunde liegenden photosynthetischen und redoxbezogenen Mechanismen her. Darüber hinaus wurde die transgenerationale Staunässe mit einem ähnlichen Mechanismus in Verbindung gebracht. Dies könnte zu den schnellen Reaktionen der Pflanzen auf Umweltveränderungen beitragen. Wie ich jedoch in dieser Arbeit gezeigt habe, ist das pflanzliche Stressgedächtnis nicht bei allen Pflanzenarten vorhanden. In Zukunft wird es wichtig sein, die Ursache für die ökologisch bedeutsamen Diskrepanzen bei den mütterlichen Effekten zwischen den Arten zu untersuchen. Unterschiedliche mütterliche Effekte zwischen den Arten könnten die Artenvielfalt erhöhen. Ein umfassenderes Verständnis des transgenerationalen Gedächtnisses könnte dazu beitragen, die Strategien zur Verbesserung von Pflanzen für wirtschaftlich und ökologisch wichtige Arten anzupassen.
From alien to native Asteraceae : how effects of climate, functional traits, and biotic interactions on population growth change with residence time
(2023) Brendel, Marco; Sheppard, Christine
Biological invasions pose a major threat to native biodiversity and even drive native species to extinction. It is thus of utmost importance to gain a better understanding of limits to population growth and spread of invasive plants. Invasion success in the introduced area is determined by the combined effects of climatic mismatches between the area of origin and the introduced area as well as biotic resistance of resident native communities. Alien plants can respond to environmental selection via changes in functional traits and thereby adapt to novel abiotic conditions. Native community species are expected to adapt to the presence of the invader by gaining eco-evolutionary experience and build-up biotic resistance over time. The aim of this thesis is to investigate interactions of alien plants with the novel abiotic and biotic environment in their introduced range over eco-evolutionary timescales. To this end, I conducted common garden experiments based on an alien-native species continuum to cover a broad range of residence times in Germany (7 to 12,000 years before present). I followed the population growth of 47 annual Asteraceae (including neophytes, archaeophytes, and natives) over two years and measured their performance in intra- and interspecific competition to answer the following questions: 1) How are effects of climatic distances between the area of origin and the introduced area as well as functional traits on population dynamics of alien plants determined by residence time? 2) How is biotic resistance of native communities towards alien plants related to residence time? 3) How are competitive outcomes between single alien and native plants shaped by residence time and serve as a predictor of range sizes? For the first question, I followed population growth of the Asteraceae in monocultures. I calculated climatic distances between the area of origin and the introduced area and measured functional traits in terms of seed mass, maximum height, and specific leaf area. Firstly, I tested whether negative effects of climatic distances on population growth weaken with residence time. Secondly, I investigated trait-demography relationships and tested if functional traits converge towards values that increase population growth. I found a strong effect of seed mass and no effects climatic distances on population growth. A strong negative relationship between seed mass and population growth resulted in directional selection of seed mass towards low values with increasing residence time. For the second question, I measured population growth of the Asteraceae in a Central European grassland community. I tested if competitive effects of the community on the Asteraceae increase with residence time (i.e. co-existence time with the native community). I used a second community native to North American grasslands that never co-existed with the Asteraceae to disentangle competitive effects related to eco-evolutionary experience of the native community from inherent competitive abilities of the Asteraceae. I compared trait-demography relationships in both community types with monocultures and found very similar competitive effects of both communities on the Asteraceae and thus no evidence for a build-up of competition-induced biotic resistance over time. Instead, invasion success was determined by a strong seed-mass-mediated trade-off between population growth in low- vs. high-competition. For the third question, I tested if the response of biomass and seed production of native targets to competition with alien and native neighbours depends on residence time. I tested if competitive effects differ between invasion status groups and explain species’ range sizes in Germany. I generally did not find a higher tolerance of native Asteraceae to competition of neighbouring aliens and natives with increasing residence time. Both established neophytes and natives showed similar competitive abilities and species’ range sizes were not influenced by competitive effects. The detected trait-demography relationships and related directional selection as a mechanism of adaptation to novel abiotic conditions improve the understanding of constraints on population growth and spread of invaders. The lack of interspecific competitive superiority as a determinant of range sizes might indicate that other mechanisms are more important for invasion success. The functional trade-off between population growth in low vs. high competition reveals that invaders that are likely to escape this trade-off should be of highest management concern. By the combination of experimental macroecology with approaches of functional and community ecology used in my study, I strongly advanced the understanding of mechanisms of limits to population growth and spread of alien plants and provide a fundamental basis for future research in invasion ecology.
The performance of and interactions between multiple co-occurring alien and native plant species
(2023) Ferenc, Viktoria; Sheppard, Christine
This thesis focuses on investigating species interactions in the context of alien species establishment, which poses severe threats to species, communities, and ecosystems due to climate change and globalization. The study emphasizes the need to understand the effects of multiple co-occurring alien species and their potential explanations, such as niche or fitness differences. The outcome of competition can also be influenced by priority effects, where earlier emerging species affect later emerging species in a given environment. Positive interactions, like facilitation, are often overlooked but play a significant role in species interactions. Legumes, known for their ability to fix atmospheric nitrogen, can facilitate alien species, leading to both severe negative effects on natives and reduced resource competition. The research conducted three common garden pot experiments to address various aspects of alien species interactions. The first experiment examined pairwise combinations of 20 alien annual plant species in Germany to identify the mechanisms driving these interactions. It tested the prevalence of competition versus facilitation and assessed the effectiveness of individual traits, hierarchical or absolute trait distances, multivariate trait or phylogenetic distance, and trait plasticity in explaining plant performance. Results indicated that while interspecific competition was more common, interspecific facilitation occurred in 24% of cases. Hierarchical trait distances provided better explanations for interactions than phylogenetic or multivariate trait distances. Accounting for trait plasticity did not necessarily improve plant performance predictions. Notably, taller individuals with lower specific leaf area than their alien neighbours exhibited increased biomass and seed production when growing together. The second experiment focused on interactions between five pairs of alien and native species. It evaluated the impact of growing with one or two alien neighbour species on native plants and manipulated the arrival time of alien or native neighbours. Generally, native species performed worse when surrounded by two alien species compared to one, although the effect varied among species. Both native and alien species experienced significant performance decreases when arriving second in the pot, while alien species tended to benefit more from early arrival. However, further studies are required to generalize these findings across multiple alien and native plants regarding neighbour species and arrival time responses. The third experiment delved into legume facilitation in more detail. It involved growing 30 annual Asteraceae species (neophytes, archaeophytes, and natives) in communities with or without legume presence. The study measured functional traits, fitness, and nitrogen characteristics to understand how legume presence affected Asteraceae fitness and the relationship between traits, nitrogen concentration, and fitness. Using the δ15N natural abundance method, the research explored whether facilitation mechanisms differed among native phytometer, neophyte, and archaeophyte Asteraceae. Specific leaf area negatively affected aboveground biomass and seed production, with a stronger effect in the absence of legumes. Nitrogen concentration was positively correlated with biomass but did not significantly increase seed production. The results suggested direct legume facilitation for the native grass phytometer Festuca rupicola when growing alongside archaeophytes but not neophytes. This indicated varied mechanisms of competition for nitrogen between natives and alien species of different residence times and deepened understanding of altered facilitative leguminous effects in the presence of alien species. Overall, this research demonstrates the application of community ecology concepts and theories to investigate alien species interactions, particularly when multiple co-occurring alien species are involved. As the rate of alien species arrival in new habitats continues to increase, understanding their combined impact on native species, communities, and ecosystems becomes increasingly crucial.
Impacts of temperature increase and change in precipitation pattern on ecophysiology, biomass allocation and yield quality of selected crops
(2023) Drebenstedt, Ireen; Högy, Petra
Climate change poses a challenge for the production of crops in the twenty-first century due to alterations in environmental conditions. In Central Europe, temperature will be increased and precipitation pattern will be altered, thereby influencing soil moisture content, physiological plant processes and crop development in agricultural areas, with impacts on crop yield and the chemical composition of seeds. Warming and drought often occur simultaneously. The combination of multiple abiotic stresses can be synergistic, leading to additive negative effects on crop productivity. To date, little information is available from multi-factor experiments analyzing interactive effects of warming and reduced precipitation in an arable field. In addition, one major issue of studying climate change effects on crop development in the long-term is that weather conditions can vary strongly between years, e.g., with hot and dry summers in comparison to cool and wet ones, which directly affects soil moisture content and indirectly affects crop development. Thus, considering yearly weather conditions seems to be important for the analyses of climate change effects on aboveground biomass and harvestable yield of crops. The aim of the present work was to identify single and combined effects of soil warming (+2.5 °C), reduced summer precipitation amount (-25%), and precipitation frequency (-50%) on crop development, ecophysiology, aboveground biomass and yield as well as on yield quality of wheat, barley, and oilseed rape grown in the Hohenheim Climate Change (HoCC) field experiment. This thesis presents novel results from the HoCC experiment in the long-term perspective. Thus, aboveground biomass and yield data (2009-2018) of the three crops were analyzed with regard to their inter-annual variability, including annual fluctuations in weather conditions.This thesis consists of three publications. In the first and second publication a field experiment within the scope of the HoCC experiment was conducted with spring barley (Hordeum vulgare L. cv. RGT Planet) and winter oilseed rape (Brassica napus L. cv. Mercedes) in 2016 and 2017. The objective was to investigate the impacts of soil warming, altered precipitation pattern and their interactions on biomass production and crop yield. In addition, it was examined, whether the simulated climate changes affecting barley photosynthesis and the seed quality compounds of oilseed rape. In the third publication, long-term plant productivity data of wheat, barley, and oilseed rape were evaluated, including aboveground biomass and yield data from the field experiment in 2018 with winter wheat (Triticum aestivum L. cv. Rebell).
Heavy metals from phosphate fertilizers in maize-based food-feed energy systems
(2023) Niño Savala, Andrea Giovanna; Fangmeier, Andreas
The problem of polluted agricultural lands with heavy metals due to anthropogenic activities, including applying phosphorous (P) fertilizers polluted with cadmium (Cd) and other metal such as uranium, has been extensively studied. Several reviews, including the one in the present dissertation, have elaborated this issue with often the same results: the application of P fertilizers with high Cd levels is strongly correlated to Cd accumulation in arable soil, which could imply environmental risks as well as health risks for humans and animals through the food chain. Therefore, these reviews have often the same conclusion: the application of low Cd-P fertilizers, either mineral, organic or recycled, is diminishing the risks of Cd pollution at the soil, crop and consumption level. However, globalization, trade politics, economy, dependency on Morocco mineral P fertilizers, and the finite stock in the raw material have challenged this possibility, especially in the European Union. Meanwhile, in China, polluted arable soils are related to other anthropogenic activities and type of fertilizers rather than Cd-polluted phosphate rock and mineral P fertilizers. At the farm level, other options to diminish Cd pollution in soil and crops, besides low Cd-P fertilizers, could consist of different fertilizer and crop management. These options were studied in this dissertation. A different P management, including different rate applications and placements, did not influence the total Cd concentration in silage maize grown in Germany, regardless of the developmental stage of the crop and the Cd levels in P fertilizer. Silage maize might take up Cd derived from P fertilizers under unpolluted soils, without high risks due to its high biomass production. However, significant changes in the labile Cd fraction were already visible after applying Cd-polluted P fertilizers at 150% of the required amount to the soil after only two growing seasons. Further research should be done to understand the correlations between the bioavailable metal fraction and the actual Cd uptake by silage maize, especially in unpolluted soils. This recommendation also follows the meta- analysis results presented in the second publication, which indicated a possible bias as most of the studies are performed under polluted conditions. Considering the results of the third and fourth publication, the Cd uptake by silage maize was strongly correlated to labile Zn in the soil and the Zn uptake at the early development stage after two field seasons. Placed P fertilizer had a significant and negative effect on the Zn uptake by young silage maize. Further research is needed to understand the behavior of Cd and Zn in the uptake process by maize under P fertilization in unpolluted soils. According to three of the four publications presented in this dissertation, the soil pH was the main soil characteristic influencing the bioavailability and the plant uptake of Cd under unpolluted conditions, regardless of the P treatment, the development stage, and the maizes intended use. However, the total Cd concentration in the soil was the dominant variable for the Cd concentration in maize grain when the soil was polluted with high Cd levels, which was the case in several experiments analyzed in the second publication. P fertilizers with average Cd contamination might enhance labile Cd accumulation in arable land and crops when applied to low biomass crops, such as wheat and legume crops. In this regard, crop management such as crop rotation in the central field experiment indicated that the wheat rotation induced a lower Cd accumulation in maize-soil systems, owing to wheat likely accumulating Cd at higher levels than other crops. The results presented in the second publication also indicated high Cd accumulation by the wheat crop: the wheat grain accumulated more Cd than the maize grain. Thus, potential hazards related to Cd accumulation in wheat grain should also be considered in wheat-maize systems. In conclusion, suitable crop rotations considering the crop-specific potential of Cd accumulation, efficient P management including soil P levels and nutrient use efficiency, and low Cd-P fertilizers remain the most viable options and the main challenge to avoid Cd accumulation in arable soils.
Fallstudien zu Stickstoffdioxid und Feinstaub - Untersuchung und Vergleich verschiedener Pflanzenarten und Dachflächen im urbanen Raum
(2022) Neher, Philipp; Fangmeier, Andreas
More and more people are living in cities. Therefore, one of the main tasks of municipalities is to ensure a good quality of life for people living in cities. Among many other factors, air quality plays a decisive role, because we all need air to live and consume many litres of it every day. This study therefore deals with the question of whether urban vegetation, especially green roofs, can contribute to an improvement in air quality. In order to answer this question, parameters reflecting air quality were recorded on several roof surfaces. The parameters investigated were primarily particles in the range of 2.5 to 80 micrometres and nitrogen dioxide (NO2). Airborne particles were recorded using Sigma-2-samplers and NO2 using Palmes tubes. On the other hand, morphological leaf characteristics of different plant species were examined microscopically and a statement was made about the "filtering capacities" of the species. In support of this, heavy metal contents in the substrate and wash-out were investigated. Investigations on roof surfaces showed that, due to the height difference, significantly lower pollutant levels were recorded on roof surfaces than at street level. For NO2, about 50 % lower values were recorded. The comparison between greened and ungreened roof surfaces showed slightly significantly lower values for both particulate matter and NO2 on greened roofs. Investigations on the different plant species showed that plants with a structurally rich leaf surface, dense and tall growth, "filter" more particles from the ambient air than low-growing species or species with a smooth leaf surface. In summary, it can be stated that green roofs can lead to a slight improvement in air quality with regard to particulate matter and NO2. The decisive factors here are the choice of plants used in greening systems and ultimately also the distance to the emitters.
Suitability of conventional flowering fields and organic lentil mixed-crops to promote biodiversity on arable land
(2020) Gayer, Christoph; Dieterich, Martin
The rapid agricultural intensification during the last decades is among the main drivers of the dramatic and ongoing biodiversity loss on earth. The decline of species diversity and associated ecosystem services due to highly intensified farming practices and structural simplified agricultural landscapes includes the reduction of species richness and abundance of species. The loss of species and related shifts in species communities can also lead to altered functional traits within species communities. It can also include deteriorated population developments of single species known to be important ecosystem service suppliers for agricultural production. In Europe, billions of euros are spent each year to support farmers for applying environmentally friendly practices, but so far biodiversity continues to decline. This calls for the development of more effective biodiversity conservation measures on agricultural land. Within the framework of agri-environmental measures, agronomically non-productive measures exist such as the establishment of flowering fields, but there are also production integrated measures such as the organic farming of crops. Further, the growing of flowering lentil mixed-crops could be a valuable, but rarely studied option to further increase the biodiversity benefits of organic farming systems. Up to that, little is known about the relative effectiveness of non-productive flowering fields under conventional management and organically farmed mono- as well as lentil mixed-crops for the promotion of biodiversity on arable land. Within the scope of this thesis, i studied biodiversity effects in response to the establishment of annual flowering fields under conventional management, organically managed winter spelt as well as organic lentil mixed-crops. These three crop-use types were compared to conventional winter wheat (control). Besides, I took into account biodiversity effects of the within-field position (field edge versus interior) as well as the surrounding landscape complexity in 500 m around each study field. To get a comprehensive overview about potential biodiversity effects and related ecosystem functions in response to the four crop-use types, I assessed the abundance, species richness and community composition of wild plants (primary producers), carabids and spiders (ground-dwelling predators) as well as butterflies and wild bees (flower-visiting arthropods). I further assessed the functional diversity of carabids as an important species group for biological pest control. To quantify functional diversity in comparison between the four crop-use types, I used the community weighted means and functional divergence of three ecological traits – body size, feeding type, and flight ability. These traits can affect mobility (body size, flight ability) as well as pest and weed seed predation (feeding type, body size) of carabids. Last, I measured the population development of colonies of Bombus terrestris, I observed weight gain, foraging activity, worker body size, queen brood cell number and stored pollen types of colonies exposed at each study field in 2018. I found clear taxon-specific effects of the total abundance and species richness in response to the studied crop-use types. No distinct differences were found for the community composition, which was similar between crop-use types. Arable wild plants benefited most strongly from organic farming, in particular from lentil mixed-crops, but also from field edges. Ground-dwelling arthropods were also mainly promoted by field edges, whereas flower-visiting arthropods solely benefited from conventional flowering fields and organic lentil mixed-crops. Carabid functional diversity was higher at the field edge than the interior irrespectively of crop-use type. Feeding type diversity (carnivorous, ominovorous, herbivorous) of carabid assemblages did also profit from conventional flowering fields and organic winter spelt. Colonies of Bombus terrestries had higher foraging activity and larger body sizes, if exposed at organic winter spelt fields, whereas weight gain and queen brood cell numbers were unaffected by local crop-use type. Pollen stores within the colonies were dominated by Phacelia (Phacelia tanacetifolia) irrespectively of crop-use type. Phacelia was part of the sown seed-mixture in flowering fields, indicating a landscape-wide attraction of flowering fields as pollen source for Bombus terrestris. Over all studies i found only minor effects of the surrounding landscape, except the negative correlation between flower cover and pollen diversity of Bombus terrestris colonies. In summary, this thesis revealed that the establishing of annual flowering fields can be an appropriate measure to enhance biodiversity in conventional farming systems. Organic lentil mixed-crops are appropriate to further increase biodiversity benefits of organic farming systems. Within the conducted studies, different crop-use types promoted specific species groups and thereby different components of biodiversity. Hence, the results of this thesis reveal, that there is no single best measure for the promotion of biodiversity on arable land. Instead, the additive effects of non-productive and productive measures as well as field edge habitats underline, that a mosaic of different types of measures hold the greatest potential to benefit overall biodiversity in agricultural landscapes. Therefore, future agri-environmental schemes should provide particular incentives for individual farmers to apply a diversity of different measures on their farmland and should foster the collaboration and spatially coordinated implementation of complementary biodiversity measures between multiple farmers at the landscape scale.
Performance and governance challenges of a government-funded microcredit program for the handloom weavers in Bangladesh
(2019) Parvin, Mst. Tania; Birner, Regina
Microfinance is an important policy tool for poverty reduction and employment generation in developing countries. The first microfinance institution was developed in Bangladesh in the 1970s. Since its inception, many studies have been conducted on different aspects of microfinance, such as outreach, impact and sustainability. However, these studies have mostly been limited to the performance of microcredit programs operated by non-government organizations (NGOs). Therefore, it is justified to shift the focus from NGOs to microcredit programs operated by the public sector. To fill this knowledge gap, a case study of Bangladesh Handloom Board (BHB)’s microcredit scheme has been conducted, which represents a publicly sponsored credit program targeting handloom weavers. Using a mixed methods approach, this thesis has analyzed three dimensions of the selected credit program: impact assessment, repayment performance, and governance challenges. These three topics are covered by three different papers in the thesis. The first two papers apply quantitative techniques whereas the third one adopts a qualitative approach for assessing the institutional viability. The objective of the first paper is to estimate the impact of BHB’s microcredit scheme on the handloom weaver’s investment behavior in Bangladesh. From a policy perspective, this analysis is relevant for two reasons. First, it fills the gaps in the impact assessment studies of credit which have largely neglected the government-run microcredit programs. Second, the article provides insights for the promotion and continuation of this public credit program. Using an Instrumental Variable (IV) Two-stage Least Squares (2SLS) regression model, the study findings reveal that the government credit program alone is not sufficient to increase the investment in the handloom sector of Bangladesh. The credit received from sources other than BHB was thought to be more relevant with regard to this goal. However, this result also implies that access to multiple sources of credit put borrowers into a debt trap, which makes them economically worse off after repaying loans with interest. As a result, productive investment does not take place through the credit program. This finding, however, does not imply that the credit program should be stopped. It is concluded that the credit amount available under this program for technology adoption in the handloom sector should be increased. Moreover, providing credit for power looms will facilitate a structural change from using handlooms to power looms, which may provide a more sustainable means of future livelihood for current handloom weavers. The second paper analyses the credit repayment of the BHB’s microcredit scheme. Considering that the repayment rate (which is regarded as one of the success factors of the credit program) was only 65% as of June 2015, this study identifies factors that contribute to such low repayment rate, which makes government-sponsored microcredit programs financially unsustainable. This analysis is important to guide the public credit institutions to design a better lending policy by focusing on the factors that require special attention while lending to the eligible borrowers. Using a Probit model, this study reveals that socioeconomic and community-level factors associated with the borrowers played an essential role in determining timely loan repayment. Some of these factors were beyond the control of the credit institution. In conclusion, this study suggests strengthening the loan monitoring system by opening up more branches so that the timely delivery of financial as well as non-financial services to borrowers can be assured. The third paper examines the governance challenges faced by the BHB. The analysis is based on the findings of the previous two papers. As the findings from both papers highlight the challenges of BHB, it is important to understand why such challenges occur when implementing a government-sponsored credit program and from where they exactly originate. This analysis also has implications for policy revision and reformulation of BHB, which should be guided by a better understanding of the organization-specific problems that a government-funded microcredit program is facing. These challenges are assessed by using a qualitative research method called Process Net-map. The use of this method helps to understand how the credit program is implemented in practice, which may deviate from the prescribed implementation plan. Moreover, this study analyzes the challenges that arise from the perspectives of both the supply-side and the demand-side stakeholders of BHB. The major finding of the first paper is supported by the outcome of this paper as it reveals that shortage of funds was the main obstacle for implementing BHB’s microcredit scheme, which failed to meet the clients’ financial needs. Besides this problem, the shortage of adequate staff was responsible for weak field administration, which is amplified by the lack of incentives to motivate them. Political influence and corruption in the system were also identified as central challenges. From the beneficiary-side, high opportunity cost to get loans, lack of non-financial services, inadequacy of funds, and difficulty in group formation were also major problems. A lack of transparency in information flow between groups was also noted as a problem. This paper concludes that a poorly designed program which fails to address the organization-specific challenges of government-run microcredit program will not improve the livelihood of the intended beneficiaries. Hence, the study recognizes the credit program’s need for a better legal and regulatory framework to address the governance challenges that are identified. The focus should be placed on flexible, demand-driven, bottom-up and participatory initiatives. Overall, the study concludes that government-run microcredit programs, affected by problems from large bureaucracies, face specific challenges, which tend to be larger than those faced by NGO-run microcredit programs. One possible solution may be an enhanced collaborative system that involves both public and private credit institutions as it may encourage cross-sector learning.
Analysis of phytosociological composition and spatial structure of the central zone of Lake Baikal Eastern coast vegetation
(2018) Brianskaia, Elena; Schmieder, Klaus
The object of this study is the terrestrial ecosystem of Lake Baikal enlisted by UNESCO as the World Heritage Site. The analysis of spatial and phytosociological structures of the vegetation can reveal important stages of its formation and future dynamics. Today, the present flora and vegetation of the complex Baikal Siberian ecosystem is reflected in studies of many Russian and international phytosociologists. However, despite the huge amount of data, the phytosociological vegetation structure and its spatial distribution of the central zone of Lake Baikal eastern coast has not been studied. By this thesis, we provide the first results about the flora, phytosociological composition of the vegetation and the soil diversity of the central zone of Lake Baikal eastern coast. Selecting the area to study, we hypothesize that this complex territory can be considered as a model biome that adjoins Lake Baikal central zone in the east. The major landscape of the studied area is composed of forests complicated by the bogged valleys of the rivers Cheremshanka, Talovka and Bezymyanka. The Katkovskaya and Chernaya Griva mountains range stretches from the northto the east. 167 relevés were performed by standard methods of the Braun-Blanquet approach. To reveal the phytosociological composition of the vegetation supervised k-means classification was performed in JUICE program. By comparing the vegetation data from the studied area (167 relevés) with data from the adjacent territories of Lake Baikal, Svyatoi Nos Peninsula and the Barguzin mountain range (589 relevés) was obtained the final prodromus of the vegetation. The soil identification was performed according to Russian soil classification. The vegetation mapping was performed in ArcGIS 10.3.1 by the supervised image classification of multispectral panchromatic imagery SPOT 6. The vegetation of the territory under study is represented by four classes. The dominant type of the vegetation is represented by forests which are classified into Vaccinio-Piceetea Br.-Bl. in Br.-Bl. et al. 1939 class. The wetland vegetation includes two classes Scheuchzerio-Caricetea nigrae (Nordh. 1936) Тх. 1937 and Oxycocco-Sphagnetea Br.-Bl et R. Tx. 1943. The vegetation of shifting sands of the coastal line is classified into Brometea korotkyi Hilbig et Korolyuk 2000 class. For all phytosociological vegetation units are identified seven soil types, such as, Lithozems, Brown soil, Soddy Brown Forest soil and Rzhavozems, Fen Peat, and Peat Gleyzem. The soil distribution demonstrates its contingence with an altitudinal gradient; however, transitioning from mountain to plain areas, a hydrological regime becomes crucial. Despite a relatively small territory under study (approx. 500 km2), the vegetation is relatively diverse. Location of the studied area within the zonal forest belt contributes to the leading position of the forest communities. The close ground water occurrence creates suitable conditions for wetland vegetation formation. Lake Baikal coastal line is considered as a refugium of the unique ancient Miocene-Pliocene xerophytic vegetation and flora. Thus, Lake Baikal water body, mountain landform and close ground water occurrence contribute to the formation of diverse vegetation communities. We suggest that the vegetation of this relatively small territory can be considered as a model within the central zone of Lake Baikal eastern coast.
Fernerkundungsgestützte Analyse und Bewertung ökologischer Auswirkungen des Anbaus von Bioenergiepflanzen auf die Agro-Biodiversität anhand der Modellierung der Habitatansprüche der Feldlerche (Alauda arvensis)
(2017) Schlager, Patric; Schmieder, Klaus
For the first time in 2002, the transformation of the conventional energy system into a system based on renewable energies was politically and legally decided in Germany. On the regional level numerous communities and municipalities followed this decision by voicing their own political resolutions, addressing the coverage of energy consumption with renewable energies. Their implementation is accompanied by a spatial expansion of bioenergy crops which lead to a controversial discussion about food safety, biodiversity and landscape change. Framed by the above mentioned discussion, this study assesses potential changes of skylark (Alauda arvensis) occurrence caused by a spatial expansion of bioenergy crops in the municipality of Schwäbisch Hall, Germany. The skylark was selected due to the comprehensive state of research about skylarks, their endangerment (“Red list of German breeding birds”), and the status as umbrella species for open agricultural landscapes (skylarks typically avoid vertical structures like hedges or edges of forests). The latter emphasizes their role as representatives for other species which are potentially affected by an expansion of bioenergy crops. This study is based on a stratified bird monitoring scheme of Baden-Württemberg, which was developed during a project that aimed to set up an indicator for species richness and was financed by the Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz (BMELV). From the bird monitoring scheme, the stratum, which covers the municipality of Schwäbisch Hall, was extracted and served as a base for the development of a Generalized Linear Habitat Model of the skylark. In order to assess potential habitat changes caused by an expansion of bioenergy crops, Schwäbisch Hall was mapped with an airborne remote sensing technology in 2011. The resulting aerial images were transformed into orthophotos and later classified (focusing on agricultural areas) with an object oriented image analysis approach. Based on the outcomes of the habitat association model and the land use classification, skylark territories were predicted for 1 km² plots covering Schwäbisch Hall. For an in-depth understanding of ecological impacts from expanded bioenergy cropping, a bioenergy scenario was developed considering § 17 BBodSchG (national soil protection act) and regional food security. Based on the scenario, skylark territories were predicted for 1 km² plots covering Schwäbisch Hall. The most reasonable habitat association model resulted in a negative binomial Generalized Linear Model with the predictors winter sown crops and mean patch size per plot. Model performance was assessed by Wald z-statistics with p-values, ANOVA, explained variance, theta, residuals, AIC, and independent field data. Field data was only available for one plot. Therefore, the field data only indicate model performance. The comparison of the model predictions with the field data resulted in an accuracy of 92.21%. The land use classification resulted in the following five classes: 1. winter sown crops (33985.78 ha), 2. maize (9621.36 ha), rapeseed (2952.36 ha), unidentified crops (7244.18 ha), and grassland (30720.88 ha). Grasslands were not mapped by remote sensing techniques, but taken from a digital landscape model. Accuracy assessment showed an overall accuracy of 89.16 % and 0.78 kappa statistics. Prediction of skylark territories based on the land use classification of 2011 resulted in 46269 territories, or a mean density of 8.4 territories per 10 ha on agricultural areas and 5.4 territories per 10 ha on agricultural and grassland combined areas. The scenario assumed a three partite crop rotation (maize, rapeseed, winter sown crops) and a mean value of 0.17 ha per inhabitant for food security. Areas for fodder production were considered in course of the calculation of food security because Schwäbisch Hall is characterized by many livestock farms, which made it necessary to avoid conflicts between potential bioenergy sites and areas for fodder production. Considering the above mentioned assumptions, Schwäbisch Hall has a bioenergy potential of 5955 ha for maize and 15033 ha for rapeseed cropping. The results of the bioenergy scenario were randomly distributed to the land use polygons which resulted from the remote sensing analysis. With that, prediction of skylark territories based on the bioenergy scenario was feasible. Skylark territories for the bioenergy scenario resulted in 36472 territories, or a mean value of 6.8 territories per 10 ha on agricultural areas and 4.3 territories per 10 ha on agricultural and grassland combined areas. Considering both land use options, skylark territories declined by 8797 in total numbers or by 19.43 % in relative numbers. In addition to the land use options described above, landscape structure and territory distribution were analyzed based on six landscape units (Naturräumliche Haupteinheiten) covering the municipality of Schwäbisch Hall. The analysis revealed an agriculturally dominated northwestern part, with high numbers and mean values of skylark territories, and a grassland/forest dominated southeastern part, with lower numbers and mean values of skylark territories. The relative decline of these territories between the two land use options within the landscape units resulted approximately in 22 % in the northwestern and approximately 11-15 % in the southeastern part. The results indicate that an expansion of bioenergy crops will have negative effects on breeding birds in open agricultural landscapes which already suffer from degraded habitat conditions. Based on the assumptions of this study, skylark territories will decline by approximately 20 % in comparison to 2011. Yet, considering the results of the indicator report of the German National Strategy on Biodiversity (BMU 2010) and the European Bird Census Council the baseline of 2011 already represents a degraded situation in terms of habitat quality for agricultural breeding birds.

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