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Hydraulic plasticity and limitations of alpine Rhododendron species


In the European Alps, Rhododendron ferrugineum grows in silicate regions while Rhododendron hirsutum is restricted to limestone areas. At geologically mixed sites, also hybrids (Rhododendron × intermedium) can occur. We hypothesised that hydraulic properties would vary with the species’ habitat requirements. Key hydraulic parameters (vulnerability to drought-induced embolism, stomata regulation) and related wood characteristics as well as diurnal courses of water potential (Ψ) and stomatal conductance were analysed on plants growing on a silicate, a limestone and a geologically mixed site. Highest embolism resistance[Ψ at 50% loss of conductivity (Ψ 50), −3.24 ± 0.18 MPa] and the highest safety margin between the Ψ at stomata closure (Ψ SC at 10% of maximal leaf conductance) and Ψ 50 were observed in R. hirsutum at the limestone site (1.57 MPa). Like in R. ferrugineum, hydraulic parameters indicated less resistance at the geologically mixed site. Highest Ψ 50 (−1.95 ± 0.12 MPa), corresponding to wide conduits and a reduced conduit wall reinforcement, was found in R. × intermedium. Diurnal courses indicated a rapid stomata closure in response to low Ψ in R. hirsutum and R. × intermedium. The plasticity in drought adaptation of R. hirsutum corresponds to its ability to colonise dry limestone areas. In contrast, hydraulic limitations of R. × intermedium may explain restrictions to rather moist sites. This study provides insight into the role of xylem hydraulics and stomata regulation in shrub water relations, interspecific and site-specific differences in drought adaptation, as well as effects of hybridisation on plant hydraulics.

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  1. Alder NN, Sperry JS, Pockman WT (1996) Root and xylem embolism, stomatal conductance, and leaf turgor in Acer grandidentatum populations along a soil moisture gradient. Oecologia 105:293–301

  2. Beikircher B, Mayr S (2009) Intraspecific differences in drought tolerance and acclimation in hydraulics of Ligustrum vulgare L. and Viburnum lantana L. Tree Physiol 29:765–775

  3. Boehm H (1893) Capillarität und Saftsteigen. Ber Dtsch Bot Ges 11:203–212

  4. Breda N, Huc R, Granier A, Dreyer E (2006) Temperate forest trees and stands under severe drought: a review of ecophysiological responses, adaptation processes and long-term consequences. Ann For Sci 63:625–644

  5. Brodribb TJ (2009) Xylem hydraulic physiology: the functional backbone of terrestrial plant productivity. Plant Sci 177:245–251

  6. Brodribb T, Hill RS (1999) The importance of xylem constraints in the distribution of conifer species. New Phytol 143:365–372

  7. Choat B, Sack L, Holbrook NM (2007) Diversity of hydraulic traits in nine Cordia species growing in tropical forests with contrasting precipitation. New Phytol 175:686–698

  8. Cochard H, Bréda N, Granier A, Aussenac G (1992) Vulnerability to air embolism of three European oak species (Quercus petraea (Matt) Liebl, Q. pubescens Willd, Q. robur L). Ann For Sci 49:225–233

  9. Cochard H, Bréda N, Granier A (1996) Whole tree hydraulic conductance and water loss regulation in Quercus during drought: evidence for stomatal control of embolism. Ann For Sci 53:197–206

  10. Cochard H, Lemoine D, Dreyer E (1999) The effects of acclimation to sunlight on the xylem vulnerability to embolism in Fagus sylvatica L. Plant Cell Environ 22:101–108

  11. Cochard H, Coll L, Le Roux X, Ameglio T (2002) Unraveling the effects of plant hydraulics on stomatal closure during water stress in walnut. Plant Physiol 128:282–290

  12. Cochard H, Casella E, Mencuccini M (2007) Xylem vulnerability to cavitation varies among poplar and willow clones and correlates with yield. Tree Physiol 27:1761–1767

  13. Cordero RA, Nilsen ET (2002) Effects of summer drought and winter freezing on stem hydraulic conductivity of Rhododendron species from contrasting climates. Tree Physiol 22:919–928

  14. Crombie DS, Milburn JA, Hipkins MF (1985) Maximum sustainable xylem sap tensions in Rhododendron and other species. Planta 163:27–33

  15. Fischer MA, Oswald K, Adler W (2008) Exkursionsflora für Österreich, Liechtenstein, Südtirol, 2nd edn. Biologiezentrum der Oberösterreichischen Landesmuseen, Linz

  16. Hacke U, Sperry JS, Pittermann J (2000) Drought experience and cavitation resistance in six shrubs from the Great Basin, Utah. Basic Appl Ecol 1:31–41

  17. Hacke UG, Sperry JS, Pockman WT, Davis SD, McCulloh KA (2001) Trends in wood density and structure are linked to prevention of xylem implosion by negative pressure. Oecologia 126:457–461

  18. Hacke UG, Sperry JS, Pittermann J (2004) Analysis of circular bordered pit function II. Gymnosperm tracheids with torus-margo pit membranes. Am J Bot 91:386–400

  19. Hacke UG, Sperry JS, Wheeler JK, Castro L (2006) Scaling of angiosperm xylem structure with safety and efficiency. Tree Physiol 26:689–701

  20. Hacke UG, Jacobsen AL, Pratt RB (2009) Xylem function of aridland shrubs from California, USA: an ecological and evolutionary analysis. Plant Cell Environ 32:1324–1333

  21. Hubbard RM, Ryan MG, Stiller V, Sperry JS (2001) Stomatal conductance and photosynthesis vary linearly with plant hydraulic conductance in ponderosa pine. Plant Cell Environ 24:113–121

  22. Jones HG, Sutherland RA (1991) Stomatal control of xylem embolism. Plant Cell Environ 14:607–612

  23. Kolb KJ, Sperry JS (1999) Differences in drought adaptation between subspecies of sagebrush (Artemisia tridentata). Ecology 80:2373–2384

  24. Körner C (2003) Alpine plant life, 2nd edn. Springer, Berlin

  25. Larcher W (1972) Der Wasserhaushalt immergrüner Pflanzen im Winter. Ber Dtsch Bot Ges 85:315–327

  26. Larcher W, Siegwolf R (1985) Development of acute frost drought in Rhododendron ferrugineum at the alpine timberline. Oecologia 67:298–300

  27. Larcher W, Wagner J (2004) Plant life of alpine rhododendrons in their environment: seventy years of ecological research in Innsbruck. Nat Med Ver Innsbruck 91:251–291

  28. Lipp CC, Nilsen ET (1997) The impact of subcanopy light environment on the hydraulic vulnerability of Rhododendron maximum to freeze-thaw cycles and drought. Plant Cell Environ 20:1264–1272

  29. Martínez-Vilalta J, Prat E, Oliveras I, Piñol J (2002) Xylem hydraulic properties of roots and stems of nine Mediterranean woody species. Oecologia 133:19–29

  30. Mayr S (2007) Limits in water relations. In: Wieser G, Tausz M (eds) Trees at their upper limit. Treelife limitation at the alpine timberline. Springer, Berlin, pp 145–162

  31. Mayr S, Wolfschwenger M, Bauer H (2002) Winter-drought induced embolism in Norway spruce (Picea abies) at the alpine timberline. Physiol Plant 115:74–80

  32. Mayr S, Gruber A, Bauer H (2003a) Repeated freeze-thaw cycles induce embolism in drought stressed conifers (Norway spruce, stone pine). Planta 217:436–441

  33. Mayr S, Schwienbacher F, Bauer H (2003b) Winter at the alpine timberline: why does embolism occur in Norway spruce but not in stone pine? Plant Physiol 131:780–792

  34. Mayr S, Hacke U, Schmid P, Schwienbacher F, Gruber A (2006) Frost drought in conifers at the alpine timberline: xylem dysfunction and adaptations. Ecology 87:3175–3185

  35. Pammenter NW, Vander Willigen C (1998) A mathematical and statistical analysis of the curves illustrating vulnerability of xylem to cavitation. Tree Physiol 18:589–593

  36. Pisek A, Larcher W (1954) Zusammenhang zwischen Austrocknungsresistenz und Frosthärte bei Immergrünen. Protoplasma 44:30–46

  37. Pittermann J, Sperry JS (2003) Tracheid diameter is the key trait determining the extent of freezing-induced embolism in conifers. Tree Physiol 23:907–914

  38. Pittermann J, Sperry JS (2006) Analysis of freeze-thaw embolism in conifers. The interaction between cavitation pressure and tracheid size. Plant Physiol 140:374–382

  39. Pockman WT, Sperry JS (2000) Vulnerability to xylem cavitation and the distribution of Sonoran Desert vegetation. Am J Bot 87:1287–1299

  40. Polatschek A (1999) Flora von Nordtirol, Osttirol und Vorarlberg. Band 2. Tiroler Landesmuseum Ferdinandeum, Innsbruck

  41. Poudyal K, Jha PK, Zobel DB, Thapa CB (2004) Patterns of leaf conductance and water potential of five Himalayan tree species. Tree Physiol 24:689–699

  42. Saliendra NZ, Sperry JS, Comstock JP (1995) Influence of leaf water status on stomatal response to humidity, hydraulic conductance, and soil drought in Betula occidentalis. Planta 196:357–366

  43. Sperry JS (2004) Coordinating stomatal and xylem functioning—an evolutionary perspective. New Phytol 162:568–570

  44. Sperry JS, Hacke UG (2002) Desert shrub water relations with respect to soil characteristics and plant functional type. Funct Ecol 16:367–378

  45. Sperry JS, Hacke UG (2004) Analysis of circular bordered pit function. I. Angiosperm vessels with homogenous pit membranes. Am J Bot 91:369–385

  46. Sperry JS, Donnelly JR, Tyree MT (1988) A method for measuring hydraulic conductivity and embolism in xylem. Plant Cell Environ 11:35–40

  47. Sperry JS, Hacke UG, Oren R, Comstock JP (2002) Water deficits and hydraulic limits to leaf water supply. Plant Cell Environ 25:251–263

  48. Sperry JS, Hacke UG, Field TS, Sano Y, Sikkema EH (2007) Hydraulic consequences of vessel evolution in angiosperms. Int J Plant Sci 168:1127–1139

  49. Taschler D, Beikircher B, Neuner G (2004) Frost resistance and ice nucleation in leaves of five woody timberline species measured in situ during shoot expansion. Tree Physiol 24:331–337

  50. Tranquillini W (1969) Photosynthese und Transpiration einiger Holzarten bei verschieden starkem Wind. Cbl Ges Forstw 86:35–48

  51. Tranquillini W (1976) Water relations and alpine timberline. In: Lange OL, Kappen L, Schulze ED (eds) Water and plant life. Ecological Studies vol 19. Springer, Berlin, pp 473–491

  52. Tutin TG, Heywood VH, Burges NA, Moore DM, Valentine DH, Walters SM, Webb DA (1972) Flora Europaea, vol 3. Cambridge University Press, Cambridge

  53. Tyree MT, Ewers FW (1991) The hydraulic architecture of trees and other woody plants. New Phytol 119:345–360

  54. Tyree MT, Sperry JS (1988) Do woody plants operate near the point of catastrophic xylem dysfunction caused by dynamic water stress? Plant Physiol 88:574–580

  55. Tyree MT, Zimmermann MH (2002) Xylem structure and the ascent of sap. Springer, Berlin

  56. Tyree MT, Davis SD, Cochard H (1994) Biophysical perspectives of xylem evolution: is there a tradeoff of hydraulic efficiency for vulnerability to dysfunction? IAWA J 15:335–360

  57. Wheeler JK, Sperry JS, Hacke UG, Hoang N (2005) Inter-vessel pitting and cavitation in woody Rosaceae and other vesselled plants: a basis for a safety versus efficiency trade-off in xylem transport. Plant Cell Environ 28:800–812

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This study was supported by APART (Austrian programme for advanced research and technology) and the Fonds zur Förderung der Wissenschaftlichen Forschung (FWF). We thank Mag. Ing. Birgit Dämon for excellent assistance. We also thank Prof. Heilmeier and the anonymous reviewers for thoughtful comments which helped to improve the manuscript.

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Correspondence to Stefan Mayr.

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Communicated by Hermann Heilmeier.

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Mayr, S., Beikircher, B., Obkircher, M. et al. Hydraulic plasticity and limitations of alpine Rhododendron species. Oecologia 164, 321–330 (2010).

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  • Drought resistance
  • Hydraulic safety
  • Stomatal conductance
  • Stomata regulation
  • Xylem anatomy