Floral evolutionary ecology

Studies of natural selection allow us to understand the process of evolution. Our group is interested in how ecological processes can lead to evolutionary change. We use floral traits as models to understand links between ecology and evolution and as a platform for understanding plant diversity with a particular interest in plant-animal interactions. Within this topic we study a wide variety of topics. These include understanding what traits are the targets of selection, the roles of agents of selection on floral traits, such as pollinators and herbivores, and variation in selection over space and time. We are also interested in how selection may act on trait correlations and potential constraints to evolution.

Representative publications:
Parachnowitsch AL. 2014. New Synthesis: The evolutionary ecology of floral volatiles. Journal of Chemical Ecology 40(8): 859.
Parachnowitsch AL and A Kessler. 2010. Pollinators exert natural selection on flower size and floral display in Penstemon digitalis. New Phytologist. 188(2): 393-402.
Parachnowitsch AL and CM Caruso. 2008. Experimental evidence that a pre-dispersal seed predator, not pollinators, exerts selection on floral traits. Ecology 89(7): 1802-1810.

(Picture: Bumblebee visiting Lobelia siphilitica.

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Holistic integration of floral traits

Classic studies of floral evolution and ecology have often focused on visual and morphological traits, while floral scent studies have remained somewhat separate. In our group we seek to blend expertise, techniques and theory from both traditions to understand floral phenotypes in a more integrated fashion. By examining more aspects of floral characters we strive to answer: 1. What traits drive particular interactions? 2. What ecological contexts are particular traits more important? 3. How relevant is correlational selection on floral traits? 4. What are the relationships between floral signals and rewards?

Representative publications:
Junker RR and AL Parachnowitsch. 2015. Working towards a holistic view on floral traits – how floral scents mediate plant-animal interactions in concert with other floral characters. Journal of Indian Academy of Science (special issue on plant volatiles) 95 (1): 43-68.
Parachnowitsch AL, RA Raguso and A Kessler. 2012. Natural selection to increase floral scent emission, but not flower size or colour in bee-pollinated Penstemon digitalis. New Phytologist. 195: 667–675.

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Floral chemical ecology

Olfactory cues can be important to floral insect visitors. Although volatile organic compounds have been identified for many flowering plants, our understanding of basic phenotypic variation and evolutionary ecology of scents in the wild is relatively (to severely) limited. As the field develops experimental protocols and statistical techniques to sample and handle floral scents from large numbers of plants, we are able to ask more in depth questions about variation in floral scents such as: 1. How variable are floral scents within and among species? 2. What are the patterns of floral scent emission, within flowers and over time? 3. How much variation in floral scents is heritable? In our group we also are exploring the functional roles of particular floral scents.

Representative publications:
Parachnowitsch AL and JS Manson. 2015. The chemical ecology of plant pollinator interactions: recent advances and future directions. Current Opinion in Insect Science 8: 41-46.
Parachnowitsch AL, RCF Burdon, RA Raguso and A Kessler. 2013. Natural selection on floral volatile production in Penstemon digitalis: Highlighting the role of linalool. Plant Signalling and Behavior 8(1).

(Picture: measuring floral scents in the field.)

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Urban ecology and evolution

A relative new aim of the group is to understand how urbanization is affecting the ecology and evolution of plants and plant-pollinator interactions. Urbanization is an area of increasing concern for conservation due to rapid changes in habitat structure and ecosystem function. Although the ecological outcomes of urbanization are garnering increased attention, evolutionary effects of these changes are poorly studied. The lack of attention to evolutionary processes may greatly skew our perception of the true effects of global change like urbanization, especially because evolutionary and ecological processes often interact. Outcrossing plants may be particularly sensitive to these changes because both the plants and their pollinators can be affected. Thus, we are using urban to rural gradients in Swedish cities to understand how urbanization impacts both the ecology and evolution of wild flowers.

Representative publications: coming in the future.

(picture:   )

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