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Pollinator activity can explain variation in outcrossing rates within individual trees


Hingston, AB and Potts, BM, Pollinator activity can explain variation in outcrossing rates within individual trees, Austral Ecology, 30, (3) pp. 319-324. ISSN 1442-9985 (2005) [Refereed Article]

DOI: doi:10.1111/j.1442-9993.2005.01476.x


We tested the hypothesis that the previously recorded higher outcrossing rates and numbers of seeds per capsule from the upper, than from the lower, branches of trees of Eucalyptus globulus (Myrtaceae) is the result of greater pollinator activity in the upper parts of the canopy. Observations of bird pollinators on 23 trees, with flowers distributed evenly between the upper and lower halves of canopies, supported this hypothesis. Birds spent significantly more time foraging, and commenced foraging significantly more often, in the upper halves than in the lower halves of canopies. Flowers in the upper halves of E. globulus canopies would therefore be expected to receive more outcross-pollen from bird pollinators because they are usually visited more often and would probably receive a greater ratio of outcross- to self-pollen. We propose that such variation in pollinator activity and outcross-pollen deposition results in different selective pressures on the mating system and pollination syndrome in different parts of the canopy. This may result in balanced selection for these traits, contributing to the maintenance of the mixed mating and generalized pollination systems of E. globulus.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Terrestrial ecology
Objective Division:Environmental Management
Objective Group:Terrestrial systems and management
Objective Field:Terrestrial biodiversity
UTAS Author:Hingston, AB (Mr Andrew Hingston)
UTAS Author:Potts, BM (Professor Brad Potts)
ID Code:33009
Year Published:2005
Web of Science® Times Cited:13
Deposited By:Geography and Environmental Studies
Deposited On:2005-08-01
Last Modified:2009-07-31

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