Computational fluid dynamics models of conifer bordered pits show how pit structure affects flow
Article first published online: 5 DEC 2011
© 2011 The Author. New Phytologist © 2011 New Phytologist Trust
Volume 193, Issue 3, pages 721–729, February 2012
How to Cite
Schulte, P. J. (2012), Computational fluid dynamics models of conifer bordered pits show how pit structure affects flow. New Phytologist, 193: 721–729. doi: 10.1111/j.1469-8137.2011.03986.x
- Issue published online: 11 JAN 2012
- Article first published online: 5 DEC 2011
- Received: 6 September 2011, Accepted: 23 October 2011
- pit membrane;
- xylem structure–function
- •The flow of xylem sap through conifer bordered pits, particularly through the pores in the pit membrane, is not well understood, but is critical for an understanding of water transport through trees.
- •Models solving the Navier–Stokes equation governing fluid flow were based on the geometry of bordered pits in black spruce (Picea mariana) and scanning electron microscopy images showing details of the pores in the margo of the pit membrane.
- •Solutions showed that the pit canals contributed a relatively small fraction of resistance to flow, whereas the torus and margo pores formed a large fraction, which depended on the structure of the individual pit. The flow through individual pores in the margo was strongly dependent on pore area, but also on the radial location of the pore with respect to the edge of the torus.
- •Model results suggest that only a few per cent of the pores in the margo account for nearly half of the flow and these pores tend to be located in the inner region of the margo where their contribution will be maximized. A high density of strands in outer portions of the margo (hence narrower pores) may be more significant for mechanical support of the torus.