Estimating Volume Flow Rates Through Xylem Conduits

American Journal of BotanyVolume 82, Issue 9 p. 1112-1116 Structure and Development Estimating volume flow rates through xylem conduits Ann M. Lewis, Corresponding Author Ann M. Lewis alewis@forwild.umass.edu Department of Forestry and Wildlife Management, University of Massachusetts, Amherst, Massachusetts, 01003-4210 Harvard Forest, Harvard University, Petersham, Massachusetts, 01366-0068Author for correspondence (Internet: alewis@forwild.umass.edu; FAX: 413-545-4358).Search for more papers by this authorEmery R. Boose, Emery R. Boose Department of Forestry and Wildlife Management, University of Massachusetts, Amherst, Massachusetts, 01003-4210 Harvard Forest, Harvard University, Petersham, Massachusetts, 01366-0068Search for more papers by this author Ann M. Lewis, Corresponding Author Ann M. Lewis alewis@forwild.umass.edu Department of Forestry and Wildlife Management, University of Massachusetts, Amherst, Massachusetts, 01003-4210 Harvard Forest, Harvard University, Petersham, Massachusetts, 01366-0068Author for correspondence (Internet: alewis@forwild.umass.edu; FAX: 413-545-4358).Search for more papers by this authorEmery R. Boose, Emery R. Boose Department of Forestry and Wildlife Management, University of Massachusetts, Amherst, Massachusetts, 01003-4210 Harvard Forest, Harvard University, Petersham, Massachusetts, 01366-0068Search for more papers by this author First published: 01 September 1995 https://doi.org/10.1002/j.1537-2197.1995.tb11581.xCitations: 77AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract We discuss the errors in common approximations of the volume flow rate for laminar flow through conduits with noncircular transverse sections. Before calculating flow rates, ideal geometric shapes are chosen to represent the noncircular transverse sections. The Hagen–Poiseuille equation used with hydraulic diameter underestimates the volume flow rate for laminar flow through conduits even with such ideal shapes. Correction factors that have been proposed for the Hagen–Poiseuille equation also lead to underestimates of the volume flow rate for those shapes. The exact solutions are sometimes difficult to attain, but rates calculated using the exact solutions for the ideal shapes may be as much as five times higher than the approximated rates for common transversely elongated shapes. Either the exact solutions or the approximations may be used to calculate volume flow rates through the xylem of plants. Both of these methods actually approximate flow through the original conduits because the shapes used are approximations of the conduits' transverse sections. We recommend using the exact solutions whenever possible; they should be closer to the real solution than other approximations. We give tables of correction factors for use in the cases where calculating volume flow rate from the approximate solution, the Hagen–Poiseuille equation, is more feasible. Obtaining theoretical volume flow rates that are larger than previously thought highlights the need to clarify the causes of differences between the theoretical rates and the smaller measured volume flow rates in plant xylem. Citing Literature Volume82, Issue9September 1995Pages 1112-1116 RelatedInformation