Abstract
Mortality and water relations of three cooccurringHakea species were studied over the first year following a wildfire in scrub-health in southwestern Australia.Hakea ruscifolia regenerated from both resprouting adults and seedlings, whereasH. smilacifolia andH. polyanthema regenerated only from seedlings. We monitored seedling and resprout survival relative to pre-fire numbers and water relations (shoot water potential, transpiration, pressure-volume parameters) in order to determine the relationship between plant mortality and water relations over the critical first summer drought. Seedlings ofH. polyanthema (few initial seedlings per parent) showed little mortality (8%), achieved through both drought avoidance (low transpiration, high predawn water potential and relative water content (RWC), substantial osmotic adjustment) and drought tolerance later in the season. Seedlings ofH. smilacifolia andH. ruscifolia (high seedling/parent ratios) showed little drought avoidance and high mortality (54–68%). The remaining seedlings spent 3–4 months in a wilted condition (up to 3.6 MPa and 45% RWC below the turgor loss point inH. ruscifolia) indicating marked drought tolerance of the survivors. In contrast to its seedlings,H. ruscifolia resprouts were successful drought avoiders and experienced no mortality. The high level of survival and drought resistance ofH. polyanthema was consistent with its large seedlings (via large seeds) and low initial fecundity. The study highlights the importance of the interaction between ecophysiology-morphology and demography in determining the recruitment strategies of plants.
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References
Bowman WD, Roberts SW (1985) Seasonal and diurnal water relations adjustments in three evergreen chaparral shrubs. Ecology 66: 738–741
Calkin HW, Pearcy RW (1984) Seasonal progressions of tissue and cell water relations parameters in evergreen and deciduous perennials. Plant Cell Environ 7: 347–352
Chapman DS, Auge RM (1984) Physiological mechanisms of drought resistance in four native ornamental perennials J Am Soc Hort Sci 119: 299–306
Cowling RM, Lamont BB, Pierce SM (1987) Seed bank dynamics of four co-occurringBanksia species. J Ecol 75: 289–302
Enright NJ, Lamont BB (1989) Seed banks, fire season, safe sites and seedling recruitment in five co-occurringBanksia species. J Ecol 77: 1111–1122
Enright NJ, Lamont BB (1992a) Recruitment variability in the resprouting shrubBanksia attenuata and nonsprouting congeners in the northern sandplain heaths of southwestern Australia. Acta Ecol 13: 727–741
Enright NJ, Lamont BB (1992b) Survival, growth and water relation ofBanksia seedlings on a sand mine rehabilitation site and adjacent scrub-heath sites. J Appl Ecol 29: 663–671
Evans RD, Black RA, Loescher WH Fellows RJ (1992) Osmotic relations of the drought-tolerant shrubArtemisia tridentata in response to water stress. Plant Cell Environ 15: 49–59
Fan S, Blake TE, Blumwald E (1994) The relative contribution of elastic and osmotic adjustments to turgor maintenance in woody species. Physiol Plant 90: 408–413
Frazer JM, Davis SD (1988) Differential survival of chaparral seedlings during the first summer drought after wildfire. Oecologia 76: 215–221
Groom PK, Lamont BB (1996a) Reproductive ecology on nonsprouting and resprouting species ofHakea in south-western Australia. In: Hopper SD, Harvey M, Chappill J, George AS (eds) Gondwanan heritage: evolution and conservation of the Western Australian biota. Surrey Beatty, Chipping, New South Wales
Groom PK, Lamont BB (1996b) Biogeography ofHakea in southwestern Australia with particular reference to fire responses and leaf type. J. Biogeog
Groom PK, Lamont BB, Kupsky L (1994) Contrasting morphology and ecophysiology of co-occurring broad and terete leaves inHakea trifurcata (Proteaceae). Aust J Bot 42: 307–320
Hansen A, Pate JS, Hansen AP (1991) Growth and reproductive performance of a seeder and a resprouter species ofBossiaea as a function of plant age after fire. Ann Bot 67: 497–509
Jones HG, Sutherland RA (1991) Slomatal control of xylem embolism. Plant Cell Environ 14: 607–612
Killian D, Cowling RM (1992) Comparative seed biology and coexistence or two fynbos shrub species. J Veg Sci 3: 637–646
Kolb KJ, Davis SD (1994) Drought tolerance and xylem embolism in co-occurring species of coastal sage and chaparral. Ecology 75: 648–659
Kummerow J, Ellis BA, Mills JN (1985) Post-fire seedling establishment ofAdenostoma fasciculatum andCeonothus greggii in southern California chaparral. Madrono 32: 148–157
Lamont BB, Bergl SM (1991) Water relations, shoot and root architecture, and phenology of three co-occurringBanksia species: no evidence for niche differentiation in the pattern of water use. Oikos 60: 291–298
Lamont BB, Witkowski ETF (1995) A test for lottery recruitment among fourBanksia species based on their demography and biological attributes. Oecologia 101: 299–308
Lamont BB, Enright NJ, Bergl SM (1989) Coexistence and competitive exclusion ofBanksia hookeriana in the presence of congeneric seedlings along a topographic gradient. Oikos 56: 39–42
Lamont BB, Witkowski ETF, Enright NJ (1993) Post-fire litter microsites: safe for seeds, unsafe for seedlings. Ecology 74: 501–512
Leishman MR, Westoby M (1994) The role of seed size in seedling establishment in dry soil conditions — experimental evidence from semi-arid species. J Ecol 82: 249–258
Matsuda K, McBride JR (1986) Difference in seedling growth morphology as a factor in the distribution of three oaks in central California. Madrono 33: 207–216
Meney KA, Nielssen GM, Dixon KW (1994) Seed patterns in Restionaceae and Epacridaceae after wildfire in kwongan in southwestern Australia. J Veg Sci 5: 5–12
Momen B, Menke JW, Welker JM (1992) Tissue water relation ofQuercus wislizenii seedlings: drought resistance in a California evergreen oak. Acta Ecol 13: 127–136
Moreno JM, Oechel WC (1992) Factors controlling post-fire seedling establishment in southern California chaparral. Oecologia 90: 50–60
Pate JS, Beard JS (1984) Kwongan: plant life of the sandplain. University of Western Australia Press, Perth
Radford S, Lamont BB (1992) An instruction manual for “Template” — a rapid, accurate programme for calculating and plotting water relations data obtained from pressure — volume studies. School of Environmental Biology, Curtin University of Technology, Perth, Western Australia
Rhizopoulou S, Davies WJ (1991) Influence of soil drying on root development, water relations and leaf growth ofCeratonia siliqua L. Oecologia 88: 41–47
Richards MB, Stock WD, Cowling RM (1995) Seedling and adult water relations of twoProtea species. Funct Ecol 9: 575–583
Saruwatari MW, Davis SD (1989) Tissue water relations of three chaparral shrub-species after wildfire. Oecologia 80: 303–308
Sinclair TR, Ludlow MM (1986) Influence of soil water supply on the plant water balance of four tropical grain legumes. Aust J Plant Physiol 13: 329–341
Thomas CM, Davis SD (1989) Recovery patterns of three chaparral shrub species after wildfire. Oecologia 80: 309–320
Tyree MT, Hammel HT (1972) The measurement of the turgor pressure and the water relations of plants by the pressure-bomb technique. J Exp Bot 23: 267–282
Tyree MT, Sperry JS (1988) Do woody plants operate near the point of catastrophic xylem dysfunction caused by dynamic water stress? Answers from a model. Plant Physiol 88: 574–580
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Richards, M.B., Lamont, B.B. Post-fire mortality and water relations of three congeneric shrub species under extreme water stress — a trade-off with fecundity?. Oecologia 107, 53–60 (1996). https://doi.org/10.1007/BF00582234
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DOI: https://doi.org/10.1007/BF00582234