Ecology of flower signals along a land use gradient

Interactions among organisms are mediated by signals, which are traits that evolved to communicate with others. Given that plant traits used for signalling to animals often fulfil multiple functions and are substantially influenced by the abiotic environment, plant-pollinator networks may be affected by changes in land use.

To investigate these coherences, I will collect quantitative data on floral colouration and rewards, which will be set against data on insect visitation. Data collection will be accomplished throughout the blooming season in three Biodiversity-Exploratories declared by the DFG (German Science Foundation). These data will be modelled according to the visual system of different pollinator groups to test various adaptive hypotheses on signal evolution and on the effects of signal diversity on plant-pollinator networks.

Since signals are the first interface in plant-animal interactions, I ask whether signal perception represents a functional mechanism to explain plant-pollinator network structure. I examine how land use changes affect floral colour diversity and study whether a decline in signal diversity leads to a concomitant decline in pollinator diversity after accounting for neutral effects of plant diversity.

Furthermore I intend to find out whether changes in pollinator composition and abundance are predictable by the sensory ecology of different insect groups and ask whether variation in colour perception contributes to niche partitioning in insects. Finally I plan to experimentally test how colour diversity affects foraging behaviour of pollinators along a land use gradient in the Exploratories. These experiments will support conclusions derived from the observed plant-pollinator networks. My studies take place in cooperation with the Insect-Plant Interactions Research Group of Dr. Nico Blüthgen at the Department of Animal Ecology and Tropical Biology at the University of Würzburg and are kindly funded by the DFG.