Former projects till 2022, for some we still publish the last results
Intraspecific variation in floral traits and interaction patterns
Classically, in trait-based as well as community ecology most studies summarize traits and interactions at species level. However, interactions as well as traits are not a species but an individual property. Thus, we investigate the differences of plant individuals in their interaction patterns (qualitative and quantitative) and the linkage of these differences to functional plant traits. Further, we explore the intraspecific variability of interactions and traits across space and time as well as in response to environmental variability.
One current focus of our work is how predicted changes in precipitation (decrease in mean precipitation and prolonged extreme droughts) alter the expression of floral traits (resources, morphology, scent and colour), associated flower-visitor interactions and the reproductive success of plant individuals. Therefore, we combine experimental field studies with indoor and outdoor behavioural experiments to understand how drought affect plant individuals and how these changes affect flower-visitor behaviour. DFG-project KU 3667/2-1: Effects of decreasing precipitation and extreme drought on intraspecific variation in floral traits and flower-visitor interactions, PhD-student: Rebecca Höfers. Collaborators: Robert R. Junker (Phillips-University Marburg, Germany), Manfred Ayasse & Steven Jansen (Ulm University, Germany) Newspaper coverage: "Blütenpracht und Duftorgie: Konkurrenzkampf unter Pflanzen" (german) |
Pollination in human-modified landscapes
Pollen transfer and pollinator diversity
Over 87% of all plant species rely on animals for pollination that transfer conspecific pollen between individuals of the same species. However, most flower visitors/pollinators are visiting several plant species and thus, also transfer heterospecific pollen which may negatively impact plant fitness. Within a community, pollen transfer (con- and hetero-specific) is link to several community properties such as plant diversity and density or pollinator diversity. With pollinator diversity declining, it is urgent to understand the affect of these changes of pollination (i.e. pollen transfer and plant fitness) within plant communities. We investigate in observational and experimental field studies how plant diversity, pollinator diversity and environmental conditions affect pollen transfer and plant-plant interaction networks. Pollinator health and pollination services Roughly 47 percent of Germany’s surface area is used for farming; 90% of this area can be considered as intensively farmed. Intensive farming aims to increase yields per unit of area resulting in monotonous farmland. In such impoverished landscapes, pollinators suffer from reduced availability of food sources and nesting sites, fragmentation of habitats and exposure to pesticides. These factors, alone or in combination, can increase stress levels in individuals and may lead to developmental deficits (e.g. morphological malformation such as asymmetric wing development), physiological changes (e.g. changes in pheromone production) or increasing disease loads (e.g. viruses). Such declines in pollinator health can reduce survival of pollinator individuals, but also affect foraging behavior, activities and preferences and ultimately pollination services. Thus, we need to understand the links between land use intensification, pollinator health and pollination services to potentially mediate negative effects, such as declining pollinator populations, and maintain pollination services in agricultural landscapes. Within our study, we will combine field measurements of pollinator health and pollination services in agricultural landscapes with common-garden experiments to understand how changes in land management and different stressors such as narrow diet, insecticides or pathogens can directly influence health factors and ecosystem functioning, i.e. pollination services. This project is embedded in the large-scale experiment Biodiversity Exploratories. Joint DFG-project "Effects of land use intensity on pollinator health and pollination services" with Manfred Ayasse & Lena Wilfert (Ulm University, Germany). PhD-students: Markus Birkenbach (Main supervisor: Jonas Kuppler, KU 3667/3-1), Florian Straub (Main supervisor: Manfred Ayasse) |
Floral scent & plant-plant communication
Plants produce a broad range of chemical signals in response to their environment. As induced response to herbivory, plants release volatile organic compounds (VOCs) that can repel herbivores or attract parasites or predators. These VOCs can also be picked up by neighbouring plant individuals (so-called eavesdropping) which may lead to phenotypic changes and a higher herbivore resistant. Plants may not only benefit from eavesdropping on herbivore-induced VOCs emitted from vegetative tissue, but also from eavesdropping on other chemical plant signals such as floral scent. Detecting the presence of neighbouring flowering conspecifics could allow plant individuals to precisely synchronize flowering and increase attractiveness for pollinators and thus increasing the likelihood of cross-pollination.
We are conducting lab and field experiments using a model plant system to explore floral scent as potential communication channel between plant individuals. Collaborators: Amy L. Parachnowitsch (University of New Brunswick, Canada) |
Master & Bachelor students (current/former)
Patrick Waldhelm (M.Sc., 2019/20)
Hülya Turgut (M.Sc./M.Ed., 2018)
Manon Peuker (M.Sc., 2018)
Tina Lindner (B.Sc., 2020)
Sonja Kottman (B.Sc., 2020)
Dennis Ehlert (B.Sc., 2019)
Jessica Wieland (B.Sc., 2019)
Sandra Voxbrunner (B.Sc., 2018)
Nicola Schmid (B.Sc., 2018)
Hülya Turgut (M.Sc./M.Ed., 2018)
Manon Peuker (M.Sc., 2018)
Tina Lindner (B.Sc., 2020)
Sonja Kottman (B.Sc., 2020)
Dennis Ehlert (B.Sc., 2019)
Jessica Wieland (B.Sc., 2019)
Sandra Voxbrunner (B.Sc., 2018)
Nicola Schmid (B.Sc., 2018)