Effects of decreasing precipitation and extreme drought on intraspecific variation in floral traits and flower-visitor interactions

• Applicant: Professor Dr. Manfred Ayasse, since 4/2022
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 398632686

Individuals of one plant species can strongly vary in their appearance (i.e. traits), e.g. display size of flowers or scent emission. Depending on the trait expression displayed by an individual, the interactions can also differ as different flower visitors react to small changes in the appearance of flowers. Such intraspecific variation may positively influence the ability of plant species and populations to cope with environmental changes as plant populations which are composed of different individuals may contain at least a few individuals that can reproduce under the new conditions. Thus, incorporating intraspecific variation in traits and species interactions can provide a better understanding how climate change affects plant species. While most studies focusing on vegetative traits, we are aiming to study intraspecific variation in floral traits and flower-visitor interactions in response to predicted changes in precipitation (i.e. decreased mean precipitation and extreme drought). As over 80% on the worlds’ plant species are pollinated by animals, floral traits and flower-visitor interactions are playing a central role in plant reproduction, alterations in trait expression may influence plant population dynamics due to changes in reproductive success of individuals. In field experiments, we will expose clones of the same plant individuals to predicted changes in precipitation to investigate climate change induced alterations of floral morphology and scent emission as well as potentially associated changes in intraspecific differences in interactions with flower-visiting insect. Further, using clones allows differentiating trait variation originating from genotypic variation (i.e. trait variation between individuals) or from phenotypic plasticity (i.e. variation of one individual under different environmental conditions). This distinction is important as high level of genotypic variation improve the potential to persist and adapt to changing and novel environmental conditions that select for trait values outside the range of plasticity of resident plants. Phenotypic plasticity, on the other hand, is important for a fast adjustment of trait expressions as response to rapid environmental change. Further, we will use lab experiments to investigate the impact of alterations in individual phenotype induced by decreasing precipitation on the behaviour of flower visitors. Thus, the proposed project will provide novel insights in the potential of plants species to respond to changes in precipitation and the effect of these changes on species interactions. Further, combining these results with data on reproduction of plant individuals will shed new light on the influences of changed precipitation on plant fitness and consequently on persistence of plant populations. Overall, these findings will strongly improve our understanding on the ability of plants to respond to climate change and the role of intraspecific variation in community ecology.

• DFG Programme: Research Grants
• International Connection: Austria
• Co-Investigators: Professor Dr. Steven Jansen; Professor Dr. Robert R. Junker
• Ehemaliger Antragsteller: Dr. Jonas Kuppler, until 3/2022