Plant and Pollination Ecology

I am interested in plant reproductive ecology, and specifically plant-pollinator interactions of Australian biota. I have been involved in several research projects in Australia and overseas investigating various aspects of plant reproductive ecology.

Pollination ecology of Trachymene incisa

An estimated 90% of flowering plant species worldwide are pollinated by animals, and most of these plants rely on several pollinator species (i.e. they are generalists). I am interested in how spatial and temporal variation in visitation rates and pollinator assemblage composition affect pollination, seed production and seedling performance, and how these interactions may shape population dynamics.

My Honours research (The University of Sydney, 2000) focused on the reproductive ecology of Trachymene incisa. I studied natural populations of T. incisa in the endangered Agnes Banks Woodland and Myall Lakes National Park.

My PhD research (The University of Sydney, 2007; digital thesis available from The University of Sydney library) focused on how spatial and temporal variation in visitation rates and pollinator assemblage composition affect pollination, seed production and seedling performance. For this, I studied Trachymene incisa and its native pollinators along the coast and northern tablelands of NSW, investigating the potential for pollinator preferences and variation in pollination in the absence of introduced honeybees.

Lasioglossum sp. visiting Trachymene incisa (photo by Yvonne Davila)

Lasioglossum sp. visiting female flowers of Trachymene incisa (photo by Yvonne Davila)

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Lasioglossum sp. on male flowers of Trachymene incisa (photo by Yvonne Davila)

Pollination networks

Since most plants are generalists in terms of pollination, many co-flowering plants will share pollinators, and therefore are linked in a pollination network. I am also interested in how plant-pollinator interaction networks are structured, and how plants with different levels of pollinator-generalisation function within that network, especially under changing conditions.

I have collaborated with Professor Glenda Wardle and Dr Tony Popic investigating the dynamic responses of flower-visitor networks to rain-driven resources pulses in Australia’s arid zone, in particular how networks are structured and function following rain-driven resource pulses. This research (Tony’s PhD) was with the Desert Ecology Research Group at The University of Sydney, and undertaken in the Simpson Desert, Qld. The desert is a dynamic place and each time I have been there, I have witnessed a completely different event: drought, flooding rain and fire (sometimes a little bit too close!). After each variable rain event a new network had been assembled, with a new set of interactions between native plants and their pollinators. I am also interested in how this unpredictable and unseasonal variation in time and space are linked to network structure and function.

Rain in the Simpson Desert in November 2011 (photo by Yvonne Davila)

Rain in the Simpson Desert, Qld, November 2011 (photo by Yvonne Davila)

Dr Aaron Greenville, Dr Anke Frank and I conduct pollinator observations on a sand dune (photo courtesy of Dr Katherine Tuft)

Dr Aaron Greenville, Dr Anke Frank and I conduct pollinator observations (photo courtesy of Dr Katherine Tuft)

Here I am using a refractometer to measure  nectar sugar content from Crotalaria cunninghamia flowers (photo courtesy of Glenda Wardle)

Here I am using a refractometer to measure nectar sugar content from Crotalaria cunninghamia flowers (photo courtesy of Prof. Glenda Wardle)

Pollen limitation of plant reproduction

Pollen limitation (PL) is the reduction in plant reproductive success as a result of inadequate quantity or quality of pollen deposition and is widespread among flowering plants. Suboptimal pollinator activity is frequently invoked as the cause of PL, and the degree to which low abundance, diversity, or efficacy of flower visitors cause PL is unknown. I am interested in how the diversity and behaviour of plant pollinators can affect plant mating and reproductive output.

As a postdoctoral fellow in 2010-2011 with the Canadian Pollinator Initiative NSERC-CANPOLIN, I worked with members of WG5 to determine whether existing evidence supports the hypothesis that pollinator diversity is directly related to PL. I was based at the University of Calgary and Simon Fraser University. This work (Davila et al. 2012) was published in a special issue of Botany titled ‘Pollination biology research in Canada: perspectives on a mutualism at different scales’.

WG5 at Kananaskis Country (Photo by Yvonne Davila)

WG5 (NSERC-CANPOLIN) at Kananaskis Country, Canada (photo by Yvonne Davila)

Cuckoo bee - Bombus (Psithyrus) sp. on Gaillardia aristata (Asteraceae) at Kananaskis Country, Canada (photo by Yvonne Davila)

Cuckoo bee – Bombus (Psithyrus) sp. on Gaillardia aristata (Asteraceae) at Kananaskis Country, Canada (photo by Yvonne Davila)

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