Abstract
The epiphytic orchid, Dimerandra emarginata, occurs in habitats characterized by high light intensities and very variable water supply. Long-term observations of the water status indicate that this species experienced at least moderate water stress over most of the year. Well-watered, it showed high rates of net CO2 uptake (A, 7 μmol m−2 s−1), high transpiration rates (E, 1.4 mmol m−2 s−1), and little nocturnal acidification. Drought induced crassulacean acid metabolism activity and resulted in a strong decline of both A and E. The same conditions also led to chronic photoinhibition as indicated by a predawn ratio of variable to maximum fluorescence (Fv/Fm) of 0.6 after 9 days of drought. Diurnal changes in fluorescence characteristics were much more pronounced. Midday ratios of dark adapted Fv/Fm were as low as 0.35, but recovered in the afternoon and were probably mostly due to non-photochemical quenching of photosynthesis. Measured water losses of leaves and stems were compared to plant water content (PWC). In large plants, about 32% of PWC was transpired on a single day under well-watered conditions. Model calculations indicate that transpiration per unit leaf area should be strongly dependent upon plant size in this species. Comparisons of calculated daily water loss, PWC and the length of drought periods suggest that D. emarginata can only survive a dry season by drawing on the water reserves of older stems and by an efficient uptake of the occasional rain.
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References
Adams WW III, Martin CE (1986) Physiological consequences of changes in life form of the Mexican epiphyte Tillandsia deppeana (Bromeliaceae). Oecologia 70: 298–304
Baker NR (1991) A possible role for photosystem II in environmental perturbations of photosynthesis. Physiol Plant 81: 563–570
Benzing DH (1987) Vascular epiphytism: taxonomic participation and adaptive diversity. Ann Mo Bot Gard 74: 183–204
Benzing DH (1990) Vascular epiphytes. General biology and related biota. Cambridge University Press, Cambridge
Benzing DH, Dahle CE (1971) The vegetative morphology, habitat preference and water balance mechanisms of the Bromeliad Tillandsia ionantha Planch. Am Midl Nat 85: 11–21
Biebl R (1964) Zum Wasserhaushalt von Tillandsia recurvata L. und Tillandsia usneoides L. auf Puerto Rico. Protoplasma 58: 345–368
Croat T (1978) Flora of Barro Colorado Island. Stanford University Press, Stanford
Demmig B, Björkman O (1987) Comparison of the effect of excessive light on chlorophyll fluorescence (77 K) and photon yield of O2 evolution in leaves of higher plants. Planta 171: 171–184
Demmig-Adams B, Adams WW III (1992) Photoprotection and other responses to high light stress. Annu Rev Plant Phys Mol Biol 43: 599–626
Dixon MA, Tyree MT (1984) A new stem hygrometer, corrected for temperature gradients and calibrated against the pressure bomb. Plant Cell Environ 7: 693–697
Gessner F (1956) Der Wasserhaushalt der Epiphyten und Lianen. In: Stocker O (ed) Pflanze und Wasser. Handbuch der Pflanzenphysiologie 3. Springer, Berlin Heidelberg New York, pp 915–950
Goh CJ, Kluge M (1989) Gas exchange and water relations in epiphytic orchids. In: Lüttge U (ed) Vascular plants as epiphytes: evolution and ecophysiology. (Ecological studies, vol 76). Springer, Berlin Heidelberg New York, pp 139–166
Griffiths H, Lüttge U, Stimmel KH, Crook CE, Griffiths NM, Smith JAC (1986) Comparative ecophysiology of CAM and C3 bromeliads. III. Environmental influences on CO2 assimilation and transpiration. Plant Cell Environ 9: 385–393
Griffiths H, Smith JAC, Lüttge U, Popp M, Cram WJ, Diaz M, Lee HSL, Medina E, Schäfer C, Stimmel KH (1989) Ecophysiology of xerophytic and halophytic vegetation of a coastal alluvial plain in northern Venezuela. IV. Tillandsia flexuosaSw. and Schomburgkia humboldtianaReichb., epiphytic CAM plants. New Phytol 111: 273–282
Griffiths H, Ong BL, Avadhani PN, Goh CJ (1989) Recycling of respiratory CO2 during crassulacean acid metabolism: alleviation of photoinhibition in Pyrrosia pilloselloides. Planta 179: 115–122
Holdridge LR, Grenke WC, Hatheway WH, Liang T, Tosi JA Jr (1971) Forest environments in tropical life zones: a pilot study. Pergamon Press, Oxford
Horton P, Ruban AV (1992) Regulation of photosystem II. Photosynth Res 34: 375–385
Johansson D (1974) Ecology of vascular epiphytes in West African rain forest. Acta Phytogeogr Suec 59: 1–136
Kitajima M, Butler WL (1975) Quenching of chlorophyll fluorescence and primary photochemistry in chloroplasts by dibromothymoquinone. Biochim Biophys Acta 376: 105–115
Krause GH, Weis E (1991) Chlorophyll fluorescence and photosynthesis: the basics. Annu Rev Plant Physiol Plant Mol Biol 42: 313–349
Larcher W (1984) Ökologie der Pflanzen, 4th edn. Ulmer, Stuttgart
Leigh EG Jr, Rand AS, Windsor DM (eds) (1982) The ecology of a tropical forest. Seasonal rhythms and long-term changes. Smithsonian Institution Press, Washington, D.C.
Lüttge U (1985) Epiphyten: Evolution und Ökophysiologie. Naturwissenschaften 72: 557–566
Lüttge U (ed) (1989) Vascular plants as epiphytes: evolution and ecophysiology. (Ecological studies, vol 76) Springer, Berlin Heidelberg New York
Maxwell C, Griffiths H, Borland AM, Broadmeadow MSJ, McDavid CR (1992) Photoinhibitory responses of the epiphytic bromeliad Guzmania monostachia during the dry season in Trinidad maintain photochemical integrity under adverse conditions. Plant Cell Environ 15: 37–47
Maxwell C, Griffiths H, Young AJ (1994) Photosynthetic acclimation to light regime and water stress by the C3-CAM epiphyte Guzmania monostachia: gas-exchange characteristics, photochemical efficiency and the xanthophyll cycle. Funct Ecol 8: 746–754
Powles SB (1984) Photoinhibition of photosynthesis induced by visible light. Annu Rev Plant Physiol 35: 15–44
Reinert F, Meirelles ST (1993) Water acquisition strategy shifts in the heterophyllous saxicolous bromeliad, Vriesea geniculata (Wawra) Wawra. Selbyana 14: 80–88
Ruban AV, Young AJ, Horton P (1993) Induction of non-photochemical energy dissipation and absorbance changes in leaves: evidence for changes in the state of light harvesting system of photosystem II in vivo. Plant Physiol 102: 741–750
Siegerist ES (1986) The genus Dimerandra. Bot Mus Leafl Harv Univ 30: 199–222
Smith JAC, Griffiths H, Lüttge U, Crook CE, Griffiths NM, Stimmel KH (1986) Comparative ecophysiology of CAM and C3 bromeliads. IV. Plant water relations. Plant Cell Environ 9: 395–410
Walter H (1951) Grundlagen der Pflanzenverbreitung. 1. Standortslehre. Ulmer, Stuttgart
Windsor DM (1990) Climate and moisture variability in a tropical forest: long-term records from Barro Colorado Island, Panamá. Smithsonian Institution, Washington
Winter K (1985) Crassulacean acid metabolism. In: Barber J, Baker NR (eds) Photosynthetic mechanisms and the environment. Topics in photosynthesis 6. Elsevier, Amsterdam. pp 329–387
Zotz G (1995) How fast does an epiphyte grow? Selbyana 16: 150–154
Zotz G, Winter K (1994a) Annual carbon balance and nitrogen use efficiency in tropical C3 and CAM epiphytes. New Phytol 126: 481–492
Zotz G, Winter K (1994b) A one-year study on carbon, water and nutrient relationships in a tropical C3-CAM hemiepiphyte, Clusia uvitana. New Phytol 127: 45–60
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Zotz, G., Tyree, M.T. Water stress in the epiphytic orchid, Dimerandra emarginata (G. Meyer) Hoehne. Oecologia 107, 151–159 (1996). https://doi.org/10.1007/BF00327898
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DOI: https://doi.org/10.1007/BF00327898