Physics in Perspective

, Volume 15, Issue 3, pp 320–358 | Cite as

The Theory of the Rise of Sap in Trees: Some Historical and Conceptual Remarks



The ability of trees to suck water from roots to leaves, sometimes to heights of over a hundred meters, is remarkable given the absence of any mechanical pump. In this study I deal with a number of issues, of both a historical and conceptual nature, in the orthodox Cohesion-Tension (CT) theory of the ascent of sap in trees. The theory relies chiefly on the exceptional cohesive and adhesive properties of water, the structural properties of trees, and the role of evaporation (“transpiration”) from leaves. But it is not the whole story. Plant scientists have been aware since the inception of the theory in the late 19th century that further processes are at work in order to “prime” the trees, the main such process – growth itself – being so obvious to them that it is often omitted from the story. Other factors depend largely on the type of tree, and are not always fully understood. For physicists, in particular, it may be helpful to see the fuller picture, which is what I attempt to provide in nontechnical terms.


Eugen Askenasy Josef Böhm Edwin B. Copeland Pierre Cruiziat Francis Darwin Henry H. Dixon George Francis FitzGerald Stephen Hales Taco Hajo van den Honert John Joly John A. Milburn Park S. Nobel J.J. Oertli William F. Picard John S. Sperry Ernst Steudle Eduard Strasburger Melvin T. Tyree Martin H. Zimmermann cohesion-tension theory rise of sap transpiration capillarity cavitation negative xylem pressure hydraulic architecture global warming climate change history of biophysics 



Detailed comments on the first draft of my paper were provided by Pierre Cruiziat and by John Sperry and members of his research group: Duncan Smith, David Love, and Allison Thompson. Their comments, much appreciated, corrected a number of errors and provided helpful suggestions for improvements. Melvin Tyree also kindly provided helpful remarks. Bryn Harris kindly transcribed the original LaTeX pdf file into Word, and Patrick Wyse Jackson, curator of the Geological Museum, Trinity College Dublin, kindly authorized reproduction of the image of John Joly. John Pannell provided guidance on key points, and special help with understanding Böhm’s 1893 paper; without his constant encouragement and inspiration the project would never have been completed. I dedicate my paper to Rom Harré, a mentor and philosopher whose extraordinarily wide interests include plant science and its history. Finally, I thank Roger H. Stuewer for his meticulous and time-consuming editorial and technical assistance with this paper, and for his encouragement generally.


  1. 1.
    Sir Isaac Newton, Opticks or A Treatise of the Reflexions, Refractions, Inflexions & Colours of Light. Based on the Fourth Edition London 1730. With a Foreword by Albert Einstein. An Introduction by Sir Edmund Whittaker. A Preface by I. Bernard Cohen (New York: Dover Publications, 1979), Query 31, pp. 375-406, on p. 394.Google Scholar
  2. 2.
    Francis Darwin, “On the Ascent of Water in Trees,” Report of the Sixty-Sixth Meeting of the British Association for the Advancement of Science held at Liverpool in September 1896 (London: John Murray, 1896), 674-683, on 678; reprinted as “Report of a Discussion on the Ascent of Water in Trees,” Annals of Botany 10 (1896), 630-643, on 635; Vines, “Discussion,” 644-647; Joly, “Discussion,” 647-660; FitzGerald, “Discussion,” 660-661.Google Scholar
  3. 3.
    J.S. Rowlinson, Cohesion: A Scientific History of Intermolecular Forces (Cambridge and New York: Cambridge University Press, 2002), p. 262.Google Scholar
  4. 4.
    Guillermo Angeles, Barbara Bond, John S. Boyer, Tim Brodribb, J. Renée Brooks, Michael J. Burns, Jeannine Cavender-Bares, Mike Clearwater, Hervé Cochard, Jonathan Comstock, Stephen D. Davis, Jean-Christophe Domec, Lisa Donovan, Frank Ewers, Barbara Gartner, Uwe Hacke, Tom Hinckley, N. Michelle Holbrook, Hamlyn G. Jones, Kathleen Kavanagh, Bev Law, Jorge López-Portillo, Claudio Lovisolo, Tim Martin, Jordi Martínez-Vilalta, Stefan Mayr, Frederick C. Meinzer, Peter Melcher, Maurizio Mencuccini, Stephen Mulkey, Andrea Nardini, Howard S. Neufeld, John Passioura, William T. Pockman, R. Brandon Pratt, Serge Rambal, Hanno Richter, Lawren Sack, Sebastiano Salleo, Andrea Schubert, Paul Schulte, Jed P. Sparks, John Sperry, Robert Teskey, and Melvin Tyree, “The Cohesion-Tension Theory,” New Phytologist 163 (2004), 451-452.Google Scholar
  5. 5.
    Ulrich Zimmermann, Heike Schneider, Lars H. Wegner, and Axel Haase, “Water ascent in tall trees: does evolution of land plants rely on a highly metastable state?” New Phytologist 162 (2004), 575-615.Google Scholar
  6. 6.
    Philippe Gerrienne, Patricia G. Gensel, Christine Strullu-Derrien, Hubert Lardeux, Philippe Steemans, and Cyrille Prestianni, “A Simple Type of Wood in Two Early Devonian Plants,” Science 333 (2011), 837.Google Scholar
  7. 7.
    David B. Lindenmayer, William F. Laurance, and Jerry F. Franklin, “Global Decline in Large Old Trees,” Science 338 (2012), 1305-1306.Google Scholar
  8. 8.
    George Koch, Stephen Sillett, Gregg Jennings, and Stephen Davis, “How Water Climbs to the Top of a 112 Meter-Tall Tree,” Essay 4.3 (2006), 5 pages, in Plant Physiology Online, Fifth Edition; website <>. They note that for California redwoods, summer fog is an important supply of water, and that direct absorption by the leaves may supplement the uptake from root capture of fog drip.
  9. 9.
    Al Carder, Forest Giants of the World Past and Present (Markham, Ontario: Fitzhenry & Whiteside, 1995), pp. 1-18, 66-78. Richard McArdle, a former chief of the U.S. Forest Service, estimated a Douglas-fir in Washington to be 120 meters in 1924. The tallest Australian eucalypt today is 100 meters, and there is strong anecdotal evidence of taller ones in the past. The tallest known Sitka spruce (Picea sitchensis) in California has a height of nearly 97 meters.Google Scholar
  10. 10.
    Joel Bourne, “Redwoods. The Super Trees,” National Geographic 216 (October 2009), 12 pages. A redwood tree’s annual rate of wood production increases with age for at least 1500 years.Google Scholar
  11. 11.
    T.T. Kozlowski and S.G. Pallardy, Physiology of Woody Plants (Second Edition San Diego, London, Boston, New York, Sydney, Tokyo, Toronto: Academic Press, 1997), p. 299. It is noteworthy that the oldest trees can live on dry sites; as befits such conditions, bristlecone pines are small, thick trees with highly reduced growth rates.Google Scholar
  12. 12.
    David Suzuki and Wayne Grady, Tree: A Life Story (Vancouver, Toronto, Berkeley: Greystone Books, 2004), p. 149.Google Scholar
  13. 13.
    B.A. Meylan and B.G. Butterfield, Three-dimensional structure of wood (Hong Kong: Chapman and Hall, Ltd., 1972), give a spectacular collection of electron microscope photographs of woody structure.Google Scholar
  14. 14.
    See, for example, Ernst Steudle, “Trees under tension,” Nature 378 (1995), 663-664, on 663.Google Scholar
  15. 15.
    Rubin Shmulsky and P. David Jones, Forest Products and Wood Science: An Introduction. (Sixth Edition New York: John Wiley & Sons, 2011), p. 443, note that the weight of wood used today as a raw material in the United States is still greater than the weight of all metals and plastics combined.Google Scholar
  16. 16.
    See, for example, Colin Tudge, The Secret Life of Trees: How They Live and Why They Matter (London: Penguin Press Science, 2006).Google Scholar
  17. 17.
    Suzuki and Grady, Tree (ref. 12), p. 68. It is noteworthy that in this elegant and highly readable book on trees, built around the life cycle of a Douglas-fir, the authors present, also in chapter 2, a confused account of the mechanism of sap rise, ultimately regarding it as a “mystery.”Google Scholar
  18. 18.
    David J Beerling, and Peter J. Franks, “The hidden cost of transpiration,” Nature 464 (2010), 495-496; Steudle, “Trees under tension” (ref. 14).Google Scholar
  19. 19.
    Paul J. Kramer and John S. Boyer, Water Relations of Plants and Soils (San Diego, New York, Boston, London, Sydney, Tokyo, Toronto: Academic Press, 1995), p. 203.Google Scholar
  20. 20.
    Ibid., p. 1447; see also Richard A. Betts, “Afforestation cools more or less,” Nature Geoscience 4 (2011), 504-505.Google Scholar
  21. 21.
    Historical sketches of varying lengths can be found in Darwin, “Report” and Vines, Joly, and FitzGerald “Discussions” (ref. 2); Edwin Bingham Copeland, “The Rise of the Transpiration Stream: An Historical and Critical Discussion,” Botanical Gazette 34 (1902), 161-193, 260-283; Henry H. Dixon, Transpiration and the Ascent of Sap in Plants (London: Macmillan and Co., 1914), Chapter IV, pp. 81-100; Edwin C. Miller, Plant Physiology; With reference to the green plant (New York and London: McGraw-Hill Book Company, 1938), pp. 855-872; Kozlowski and Pallardy, Physiology of Woody Plants (ref. 11), pp. 259-260; K.N.H. Greenidge, “Ascent of sap,” Annual Review of Plant Physiology 8 (1957), 237-256; William F. Pickard, “The Ascent of Sap in Plants,” Progress in Biophysics and Molecular Biology 37 (1981), 181-229; and especially the online essay by Hanno Richter and Pierre Cruiziat, “A Brief History of the Study of Water Movement in the Xylem,” Essay 4.1 (2002), in Plant Physiology Online, Fifth Edition, 5 pages, website <>.
  22. 22.
    Succinct outlines of the CT theory are found in N. Michele Holbrook, Maclej A. Zwieniecki, and Peter J. Melcher, “The Dynamics of ‘Dead Wood’: Maintenance of Water Transport Through Plant Stems,” Integrative and Comparative Biology 42 (2002), 492-496, and Pierre Cruiziat and Hanno Richter, “The Cohesion-Tension Theory at Work,” Essay 4.2 (2006), in Plant Physiology Online, Fifth Edition, 4 pages, website <>. More detailed review papers are Greenidge, “Ascent of sap” (ref. 21); M.J. Canny, “Flow and Transport in Plants,” Annual RevXylemiew of Fluid Mechanics 9 (1977), 275-296; and Ernst Steudle, “The Cohesion-Tension Mechanism and the Acquisition of Water by Plant Roots,” Annual Review of Plant Physiology and Plant Molecular Biology 52 (2001), 847-875. Lengthier treatments are found in in the textbooks of Kramer and Boyer, Water Relations (ref. 19), pp. 234-251, Kozlowski and Pallardy, Physiology of Woody Plants (ref. 11), pp. 259-260; M.T. Tyree and M.H. Zimmermann, Xylem Structure and the Ascent of Sap (Berlin, Heidelberg, New York: Springer-Verlag, 2002), pp. 49-88, this being the second edition of the authoritative Martin H. Zimmermann, Xylem Structure and the Ascent of Sap (Berlin, Heidlberg, New York, Tokyo: Springer Verlag, 1983), pp. 37-65; Wilfried Ehlers and Michael Goss, Water Dynamics in Plant Production (Wallingford and Cambridge, Mass.: CABI Publishing, 2003), pp. 82-84; and Park S. Nobel, Physicochemical and Environmental Plant Physiology (Third Edition Amsterdam: Elsevier Academic Press, 2005), p. 459. For a physicist, the technical review paper by Pickard, “Ascent of Sap in Plants” (ref. 21), may be the most informative and satisfying, though it is somewhat out of date, particularly in relation to mechanisms for refilling embolized xylem conduits. An excellent, up-to-date, somewhat less technical review is John S. Sperry, “Hydraulics of Vascular Water Transport,” in Przemyslaw Wojtaszek, ed., Mechanical Integration of Plant Cells and Plants [Signaling and Communication in Plants, Vol. 9] (Berlin and Heidelberg: Springer-Verlag, 2011), pp. 303-327. The literature is huge; these publications represent a very small selection; a useful list of key papers is found in Angeles, et al., “Cohesion-Tension Theory” (ref. 4).
  23. 23.
    Quoted in Ehlers and Goss, Water Dynamics (ref. 22), p. 82, who attribute this quotation to Josef Böhm, “Capillarität und Saftsteigen,” Bericht der Deutschen Botanischen Gesellschaft 11 (1893), 203-212, on 207.Google Scholar
  24. 24.
    Eduard Strasburger, Ueber den Bau und die Verrichtungen der Leitungsbahnen in den Pflanzen (Jena: Gustav Fischer, 1891); idem, Ueber das Saftsteigen (Jena: Gustav Fischer, 1893).Google Scholar
  25. 25.
    Darwin, “Report” (ref. 2), p. 640.Google Scholar
  26. 26.
    Ibid., p. 631; Copeland, “Rise of the Transpiration Stream” (ref. 21), provides much detail on the range of ideas and experimental evidence being brought to bear on the issue in the 19th century – and his own skepticism about the validity of the CT theory.Google Scholar
  27. 27.
    Herman Helmholtz, “Ueber galvanische Polarisation in gasfreien Flüssigkeiten” [1873], in Wissenschaftliche Abhandlungern. Erster Band (Leipzig: Johann Ambrosius Barth, 1882), pp. 821-834, on p. 830.Google Scholar
  28. 28.
    Böhm, “Capillarität und Saftsteigen,” (ref. 23), p. 206. For a useful summary of Böhm’s energetic experimental work on the rise of sap, see Ehlers and Goss, Water Dynamics (ref. 22), pp. 82-84. The translation from the German of these passages is due to John Pannell (private communication).Google Scholar
  29. 29.
    Patrick N. Wyse Jackson, “A Man of Invention: John Joly (1857-1933), Engineer, Physicist and Geologist,” in David Scott, ed., Treasures of the Mind. A Trinity College Dublin Quatercentenary Exhibition (London: Sotheby’s, 1992), pp. 89-96.Google Scholar
  30. 30.
    Michael Jones, “‘A Name Writ in Water’: Henry Horatio Dixon 1869-1953,” in Scott, Treasures of the Mind (ref. 29), pp. 97-103; online at website <>, 5 pages.
  31. 31.
    Henry H. Dixon and J. Joly, “On the Ascent of Sap” (Abstract), Proceedings of the Royal Society of London 57 (1894), 3-5.Google Scholar
  32. 32.
    Henry H. Dixon and John Joly, “On the Ascent of Sap,” Philosophical Transactions of the Royal Society of London B 186 (1895), 563-576.Google Scholar
  33. 33.
    Ibid., p. 563.Google Scholar
  34. 34.
    Copeland, “Rise of the Transpiration Stream” (ref. 21), p. 186. E. Askenasy, “Ueber das Saftsteigen,” Verhandlungen des Naturhistorisch-Medizinischen Vereins zu Heidelberg 5 (1896), 325-345; idem, “Beitrage zur Erklrung des Saftsteigens,” ibid., 429-448.Google Scholar
  35. 35.
    Joly, “Discussion” (ref. 2), p. 647.Google Scholar
  36. 36.
    For details, see Darwin, “Report” (ref. 2), pp. 635-642; Vines, “Discussion: (ref. 2), pp. 646-647; Joly, “Discussion” (ref. 2), pp. 647-654; FitzGerald, “Duscussion: (ref. 2), pp. 660-661; see also Pickard, “Ascent of Sap in Plants” (ref. 21), p. 220.Google Scholar
  37. 37.
    Pickard, “Ascent of Sap in Plants” (ref. 21), p. 185.Google Scholar
  38. 38.
    Joly, “Discussion” (ref. 2), p. 648.Google Scholar
  39. 39.
    Richter and Cruiziat, “Brief History” (ref. 21), p. 2 of 5.Google Scholar
  40. 40.
  41. 41.
    Darwin, “Report” (ref. 2), p. 635.Google Scholar
  42. 42.
    Joly, “Discussion” (ref. 2), pp. 648-649.Google Scholar
  43. 43.
    See, for example, Steudle, “Cohesion-Tension Mechanism” (ref. 22), p. 854.Google Scholar
  44. 44.
    Joly, “Discussion” ref. 2), p. 652, where Joly refers to a model involving a porous pot connected to a supply of water, but the argument is supposed to illuminate what happens in trees.Google Scholar
  45. 45.
    Pickard, “Ascent of Sap in Plants” (ref. 21), pp. 220-221.Google Scholar
  46. 46.
    Joly, “Discussion” (ref. 2), p. 659.Google Scholar
  47. 47.
    Dixon, Transpiration (ref. 21), p. 29. It is noteworthy that the five Böhm papers cited by Dixon do not include his 1893 paper.Google Scholar
  48. 48.
    Stephen Hales, Vegetable Staticks: Or, An Account of some Statical Experiments on the Sap in VEGETABLES, etc. (London: W. and J. Innys and T. Woodward, 1727; reprinted London: Macdonald and New York: American Elsevier, 1969).Google Scholar
  49. 49.
    R. Harré, The Method of Science. A Course in Understanding Science, based upon the De Magnete of William Gilbert, and the Vegetable Staticks of Stephen Hales (London and Winchester: Wykeham Publications and New York: Springer-Verlag, 1970), p. 65. He includes a short biography of Hales in Chapter 7, pp. 70-76; amongst Hales’s many contributions to science was the discovery of carbon dioxide in air.Google Scholar
  50. 50.
    Franz Floto, “Stephen Hales and the cohesion theory,” Trends in Plant Science 4 (1999), 209.Google Scholar
  51. 51.
    Hales, Vegetable Staticks (ref. 48), p. 43.Google Scholar
  52. 52.
    Ibid., p. 56. It seems that Hales himself may not have been the first to connect capillarity with the rise of sap; see Dixon, Transpiration (ref. 21), p. 27, who refers to the 1723 views of Christian Wolff who “believed that the forces involved were the expansion of air and capillarity.”.Google Scholar
  53. 53.
    Rowlinson, Cohesion (ref. 3), p. 264.Google Scholar
  54. 54.
    Ibid., Section 3.2, pp. 86-102, for an account of their work, particularly related to capillarity.Google Scholar
  55. 55.
    For details of the early work in the field, see George S. Kell, “Early observations of negative pressures in liquids,” American Journal of Physics 51 (1983), 1038-1041.Google Scholar
  56. 56.
    David H. Trevena, “Marcelin Berthelot’s First Publication in 1850, on the Subjection of Liquids to Tension,” Annals of Science 35 (1978), 45-54.Google Scholar
  57. 57.
    Hales, Vegetable Staticks (ref. 48), p. 9; Darwin, “Report” (ref. 2), p. 630.Google Scholar
  58. 58.
    See, in particular. Steudle, “Trees under tension” (ref. 14), p. 663, who suggests that nonbotanists typically make the mistake of attributing sap rise to, if anything, capillary action in the xylem.Google Scholar
  59. 59.
    Hales, Vegetable Staticks (ref. 48), pp. 77-78. It is hard to reconcile this passage with the claim by Beerling and Franks, “The hidden cost of transpiration” (ref. 18), p. 496, that Hales, despite being aware of the role of “perspiration” in the ascent of sap, did not discover that plants transpire water from leaves.Google Scholar
  60. 60.
    P.F. Scholander, Warner E. Love, and John W. Kanwisher, “The Rise of Sap in Tall Grapevines,” Plant Physiology 30 (1955), 93-104. Studies include that of the common northern grapevine (Vitis labrusca), which can sometimes attain heights of 17 to 18 meters in wooded areas in Massachusetts.Google Scholar
  61. 61.
    As suggested by William F. Pickard, “How might a Tracheary Element which is Embolized by Day be Healed by Night?” Journal of Theoretical Biology 141 (1989), 259-279; the positive-pressure mechanism in tall vines is based on temperature-associated osmotic water uptake from rehydrated cells of the bark. It is noteworthy that Hales, Vegetable Staticks (ref. 48), Chapter III, pp. 57-68, performed the first published experiments designed to measure root pressure, in grapevines (Vitis vinifera).Google Scholar
  62. 62.
    Pickard, “How might a Tracheary Element” (ref. 61), p. 264, and Melvin T. Tyree; Sebastiano Salleo; Andrea Nardini; Maria Assunta Lo Gullo, and Roberto Mosca, “Refilling of Embolized Vessels in Young Stems of Laurel. Do We Need a New Paradigm?” Plant Physiology 120 (1999), 11-21.Google Scholar
  63. 63.
    Nobel, Physicochemical and Environmental Plant Physiology (ref. 22), p. 53.Google Scholar
  64. 64.
    Pickard, “How might a Tracheary Element” (ref. 61), p. 268.Google Scholar
  65. 65.
    S.H. Vines, “The Suction-force of Transpiring Branches,” Annals of Botany 10 (1896), 429-444. The happily-named Vines was measuring significant tension within leafless branches”; see Vines, “Discussion: (ref. 2), pp. 644-647. This capillarity view has a certain amount in common with the “imbibition” theory of sap rise that was prominent prior to the 1880s and largely associated with the name of the great German botanist Julius von Sachs (1832-1897), though this theory held that the flow of sap takes place within the walls of xylem conduits; see Copeland, “Rise of the Transpiration Stream” (ref. 21), pp. 179-181, and Dixon Transpiration, (ref. 21), pp. 83-84.Google Scholar
  66. 66.
    For remarks on the farsighted 1886 work of Nägeli, see Copeland, “Rise of the Transpiration Stream” (ref. 21), pp. 183-185.Google Scholar
  67. 67.
    See in particular the survey of results in Greenidge “Ascent of sap” (ref. 21), pp. 238-249.Google Scholar
  68. 68.
    Tyree and Zimmermann, Xylem Structure (ref. 22), p. 62.Google Scholar
  69. 69.
    M.F. Donny, “On the Cohesion of Liquids and their Adhesion to Solid Bodies,” Philosophical Magazine 28 (1846), [291]-294. Hasok Chang, Inventing Temperature: Measurement and Scientific Progress (Oxford and New York: Oxford University Press, 2004), pp. 8-39, provides a fascinating treatment of the history of the theory of boiling.Google Scholar
  70. 70.
    J.J. Oertli, “The stability of water under tension in the xylem,” Zeitschrift für Pflanzenphysiologie 65 (1971), 195-209, on 208.Google Scholar
  71. 71.
    Ibid., p. 196, and Pickard, “Ascent of Sap in Plants” (ref. 21), Section IV, pp. 198-208.Google Scholar
  72. 72.
    Oertli, “The stability of water” (ref. 70), p. 207. The point seems to be widely accepted. “The conditions for heterogeneous nucleation at preexistent sites appear to be equally hard to fulfill: the tracheary element is presumably water filled from earliest differentiation with the result that its putatively hydrophilic boundaries should be thoroughly wet and unlikely to stabilize nuclei….”; see Pickard, “Ascent of Sap in Plants” (ref. 21), pp. 205, 195. “Xylem conduits are water filled from inception and contain no entrapped air bubbles that could nucleate cavitation”; see M.T. Tyree and J.S. Sperry, “Vulnerability of Xylem to Cavitation and Embolism,” Annual Review of Plant Physiology and Plant Molecular Biology 40 (1989), 19-38, on 20.Google Scholar
  73. 73.
    Kramer and Boyer, Water Relations (ref. 19), p. 203. It should be noted that this remark occurs in the context of a discussion of how important transpiration is for the growth of a plant.Google Scholar
  74. 74.
    Sperry, “Hydraulics” (ref. 22), p. 308.Google Scholar
  75. 75.
    Steudle, “Cohesion-Tension Mechanism” (ref. 22), p. 854.Google Scholar
  76. 76.
    For a review of the mechanism of cell growth in plants, and the role of osmosis therein, see J.S. Boyer, “Water Transport,” Annual Review of Plant Physiology 36 (1985), 473-516, on 492-500, and John S. Boyer, A.J. Cavalieri, and E.-D. Schulze, “Control of the rate of cell enlargement: Excision, wall relaxation, and growth-induced water potentials,” Planta 163 (1985), 527-543. John Sperry has pointed out to me (private communication) that in cell growth, as opposed to transpiration, the air-water meniscus is stressed from below, but in both cases the pressure drop is most proximally generated by the air-water meniscus by way of capillary action.Google Scholar
  77. 77.
    J.S. Boyer, “Cell enlargement and growth-induced water potentials,” Physiologia Plantarum 73 (1988), 311-316.Google Scholar
  78. 78.
    Dixon and Joly, “On the Ascent of Sap” (ref. 32), p. 568.Google Scholar
  79. 79.
    These results were reiterated in Dixon, Transpiration (ref. 21), p. 87.Google Scholar
  80. 80.
    Dixon and Joly, “On the Ascent of sap” (ref. 32), p. 572.Google Scholar
  81. 81.
    Tyree and Sperry, “Vulnerability of Xylem” (ref. 72), p. 26. Apart from vines, root pressure can act to recover embolized xylem conduits in herbs, shrubs, and small trees; it has never been recorded in gymnosperms or in most forest trees; see Tyree, Salleo, Nardini, Assunta Lo Gullo, and Mosca, “Refilling of Embolized Vessels” (ref. 62).Google Scholar
  82. 82.
    Dixon, Transpiration (ref. 21), p. 210.Google Scholar
  83. 83.
    Pickard, “Ascent of Sap in Plants” (ref. 21), pp. 205-208.Google Scholar
  84. 84.
    Tyree and Sperry, “Vulnerability of Xylem” (ref. 72).Google Scholar
  85. 85.
    For further details on the nature of cavitation, see Tyree and Zimmermann, Xylem Structure (ref. 22), section 4.1, pp. 89-94.Google Scholar
  86. 86.
    Hales, Vegetable Staticks (ref. 48), Chapter IV, pp. 69-84.Google Scholar
  87. 87.
    Pierre Cruiziat, Hervé Cochard, and Thierry Améglio, “Hydraulic architecture of trees: main concepts and results,” Annals of Forrest Science 59 (2002), 723-752, on 736.Google Scholar
  88. 88.
    For a brief review of this mechanism, see James K. Wheeler and N. Michele Holbrook, “Cavitation and Refilling,” Essay 4.4 (2007), in Plant Physiology Online, Fifth Edition, 6 pages, website <>; for more detail see also Cruiziat, Cochard, and Améglio, “Hydraulic architecture of trees” (ref. 87), pp. 734-741, and especially Holbrook, Zwieniecki, and Melcher, “Dynamics” (ref. 22), pp. 493-495.
  89. 89.
    Clark L. Stevens and Russell L. Eggert, “Observations on the Causes of the Fow of Sap in Red Maple,” Plant Physiology 20 (1945), 636-648, on 647-648.Google Scholar
  90. 90.
    For a useful review, see Tyree and Zimmermann, Xylem Structure (ref. 22), Section 3.9, pp. 81-88.Google Scholar
  91. 91.
    For details of the two main competing models, and recent anatomical evidence in favor of the 1995 osmotic model due to Tyree, see Damien Cirelli; Richard Jagels, and Melvin T. Tyree, “Toward an improved model of maple sap exudation: the location and role of osmotic barriers in sugar maple, butternut and white birch,” Tree Physiology 28 (2008), 1145-1155.Google Scholar
  92. 92.
    Pickard, “Ascent of Sap in Plants” (ref. 21), p. 223.Google Scholar
  93. 93.
    John A. Milburn, “Sap Ascent in Vascular Plants: Challengers to the Cohesion Theory Ignore the Significance of Immature Xylem and the Recycling of Münch Water,” Annals of Botany 78 (1996), 399-407.Google Scholar
  94. 94.
    U. Zimmermann, F.C Meinzer, R. Bankert, J.J. Zhu, H. Schneider, G. Goldstein, E. Kuchenbrod, and A. Haase, “Xylem water transport: is the available evidence consistent with the cohesion theory?” Plant, Cell and Environment 17 (1994), 1169-1181, and Ulrich Zimmermann, Frederick. Meinzer, and Freidrich-Wilhelm Bentrup, “How Does Water Ascend in Tall Trees and Other Vascular Plants?” Annals of Botany 76 (1995), 545-551.Google Scholar
  95. 95.
    John S. Sperry, “Limitations on Stem Water Transport and Their Consequences,” in Barbara L. Gartner, ed., Plant Stems: Physiology and Functional Morphology (San Diego, New York, Boston, London, Sydney, Tokyo, Toronto: Academic Press, 1995), pp. 105-124, and J.S. Sperry, N.Z. Saliendra, W.T. Pockman, H. Cochard, P. Cruiziat, S.D. Davis, F.W. Ewers, and M.T. Tyree, “New evidence for large negative xylem pressures and their measurement by the pressure chamber method,” Plant, Cell and Environment 19 (1996), 427-436.Google Scholar
  96. 96.
    William T. Pockman, John S. Sperry, and James W. O’Leary, “Sustained and significant negative water pressure in xylem,” Nature 378 (1995), 715-716.Google Scholar
  97. 97.
    Milburn, “Sap Ascent” (ref. 93); Sperry, Saliendra, Pockman, Cochard, Cruiziat, Davis, Ewers, and Tyree, “New evidence” (ref. 95), pp. 432-435; Melvin T. Tyree, The Cohesion-Tension theory of sap ascent: current controversies,” Journal of Experimental Botany 48 (1997), 1753-1765; Chunfang Wei, Ernst Steudle, and Melvin T. Tyree, “Water ascent in plants: do ongoing controversies have a sound basis?” Trends in Plant Science 4 (1999), 372-375, and the reply to the prior paper in Ulrich Zimmermann, Hans-Jürgen Wagner, Heike Schneider, Markus Rokitta, Axel Haase, and Freidrich-Wilhelm Bentrup, “Water ascent in plants: the ongoing debate,” ibid. 5 (2000), 145-146; for a detailed analysis of the pressure-probe tool, see A. Deri Tomos and Roger A. Leigh, “THE PRESSURE PROBE: A Versatile Tool in Plant Cell Physiology,” Annual Review of Plant Physiology and Plant Molecular Biology 50 (1999), 447-472.Google Scholar
  98. 98.
    See Harvey R. Brown, Physical Relativity: Space-time structure from a Dynamical Perspective (Oxford: Clarendon Press, 2005), pp. 86-87, for the similar episode in the history of the special theory of relativity involving Kauffmann’s experimental “refutation” of the Lorentz-Einstein theory in experiments performed between 1901 and 1905.Google Scholar
  99. 99.
    T.H. van den Honert, “Water Transport in Plants as a Catenary Process,” Discussions of the Faraday Society 3 (1948), 146-153.Google Scholar
  100. 100.
    A review of the hydraulics of leaves, which represent an important hydraulic bottleneck in trees, is found in Lawren Sack and N. Michele Holbrook, “Leaf Hydraulics,” Annual Review of Plant Biology 57 (2006), 361-381, and Athena D. McKown; Hervé Cochard, and Lawren Sack, “Decoding Leaf Hydraulics with a Spatially Explicit Model: Principles of Venation Architecture and Implications for Its Evolution,” The American Naturalist 175 (2010), 447-460. The latter is the first detailed examination of the hydraulic consequences and implications of key leaf venation traits for the economics, ecology, and evolution of plant transport capacity.Google Scholar
  101. 101.
    Holbrook, Zwieniecki, and Melcher, “Dynamics” (ref. 22), p. 495, and further references therein.Google Scholar
  102. 102.
    For reviews, see Melvin T. Tyree and Frank W. Ewers, “The hydraulic architecture of trees and other woody plants,” New Phytologist 119 (1991), 345-360, and Cruiziat, Cochard, and Améglio, “Hydraulic architecture of trees” (ref. 87).Google Scholar
  103. 103.
    Frederick C. Meinzer; Shelley A. James, and Guillermo Goldstein, “Dynamics of transpiration, sap flow and use of stored water in tropical forest canopy trees,” Tree Physiology 24 (2004), 901-909.Google Scholar
  104. 104.
    F.C. Meinzer, J.R. Brooks, J.-C. Domec, B.L. Gartner, J.M. Warren, D.R. Woodruff, K. Bible, and D.C. Shaw, “Dynamics of water transport and storage in conifers studied with deuterium and heat tracing techniques,” Plant, Cell and Environment 29 (2006), 105-114, on 105.Google Scholar
  105. 105.
    For more details, see Tyree and Zimmermann, Xylem Structure (ref. 22), Section 4.8, pp. 132-141. For a review of water storage in plants, see N. Michele Holbrook, “Stem Water Storage,” in Gartner, Plant Stems (ref. 95), pp. 151-174.Google Scholar

Copyright information

© Springer Basel 2013

Authors and Affiliations

  1. 1.Faculty of PhilosophyUniversity of OxfordOxfordUK

Personalised recommendations