title: Conifer ovulate cones accumulate pollen principally by simple impaction.
abstract: In many pine species (Family Pinaceae), ovulate cones structurally resemble a turbine, which has been widely interpreted as an adaptation for improving pollination by producing complex aerodynamic effects. We tested the turbine interpretation by quantifying patterns of pollen accumulation on ovulate cones in a wind tunnel and by using simulation models based on computational fluid dynamics. We used computer-aided design and computed tomography to create computational fluid dynamics model cones. We studied three species: Pinus radiata, Pinus sylvestris, and Cedrus libani. Irrespective of the approach or species studied, we found no evidence that turbine-like aerodynamics made a significant contribution to pollen accumulation, which instead occurred primarily by simple impaction. Consequently, we suggest alternative adaptive interpretations for the structure of ovulate cones.
authors.affiliation: School of Biosciences, University of Exeter, Hatherly Laboratories, Prince of Wales Road, Exeter EX4 4PS, United Kingdom. j.e.cresswell@ex.ac.uk
authors.forename: James E
authors.initials: JE
authors.lastname: Cresswell
authors.forename: Kevin
authors.initials: K
authors.lastname: Henning
authors.forename: Christophe
authors.initials: C
authors.lastname: Pennel
authors.forename: Mohamed
authors.initials: M
authors.lastname: Lahoubi
authors.forename: Michael A
authors.initials: MA
authors.lastname: Patrick
authors.forename: Phillipe G
authors.initials: PG
authors.lastname: Young
authors.forename: Gavin R
authors.initials: GR
authors.lastname: Tabor
mesh_terms: D011058:Pollen / Q000378:metabolism*; D054817:Pollination; D064028:Tracheophyta / Q000378:metabolism / Q000502:physiology*