Abstract
Pollination ofLaurus azorica (Lauraceae), a dioecious Macaronesian tree, was studied. Male and female trees had the same size distribution. The population had 2.5 times as many male trees as females. In addition, males produced more flowers, and their inflorescences lasted longer. Individual flower lifetime and length of flowering season were the same in both sexes. Between the years of observation, one tree changed sex. Pollinators wereHalictinae bees and the flyTachina canariensis. The bees collected pollen and nectar and the fly collected nectar from both sexes. Both species visited other plants as well. The evolution of breeding systems inLauraceae is discussed.
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Ackerley, D. D., Rankin-de-merona, J. M., Rodrigues, W. A., 1990: Tree densities and sex ratios in breeding populations of dioecious Central AmazonianMyristicaceae. — J. Trop. Ecol.6: 239–248.
Armstrong, J. E., Irvine, A. K., 1989: Flowering, sex ratios, pollen-ovule ratios, fruit set, and reproductive effort of a dioecious tree,Myristica insipida (Myristicaceae), in two different rain forest communities. — Amer. J. Bot.76: 74–85.
Aronne, G., Wilcock, C. C., Pizzolongo, P., 1993: Pollination biology and sexual differentiation ofOxyris alba (Santalaceae) in the Mediterranean region. — Pl. Syst. Evol.188: 1–16.
Barbero, M., Benabid, A., Peyre, C., Quézel, P., 1981: Sur la presence au Maroc deLaurus azorica (Seub.)Franco. — Anales Jard. Bot. Madrid37: 467–472.
Bawa, K. S., 1980: Evolution of dioecy in flowering plants. — Annual Rev. Ecol. Syst.11: 15–39.
Beach, J. H., 1981: Pollinator foraging and the evolution of dioecy. — Amer. Naturalist118: 572–577.
Bramwell, D., Bramwell, Z. I., 1990: Flores silvestres de las Islas Canarias. — Madrid: Rueda.
Carr, D. E., 1990: Sexual dimorphism and fruit production in a dioecious understorey tree,Ilex opaca Ait. — Oecologia85: 381–388.
Ceballos, L., Ortuño, F., 1951: Estudio sobre la vegetacion y la flora forestal de las Canarias occidentales. — Madrid: Ministerio de Agricultura.
Charlesworth, D., 1984: Androdioecy and the evolution of dioecy. — Biol. J. Linn. Soc.22: 333–348.
Cipollini, M. L., Wallace-Senft, D. A., Whigham, D. F., 1994: A model of patch dynamics, seed dispersal and sex ratio in the dioecious shrubLindera benzoin (Lauraceae). — J. Ecol.82: 621–633.
Cruden, R. W., 1977: Pollen-ovule ratios: A conservative indicator of breeding systems in flowering plants. — Evolution31: 32–46.
Delesalle, V. A., Muenchow, G. E., 1992: Opportunities for selfing and inbreeding depression inSagittaria congeners (Alismataceae) with contrasting sexual systems. — Evol. Trends Pl.6: 81–91.
Delph, L. F., 1990: The evolution of gender dimorphism in New ZealandHebe (Scrophulariaceae) species. — Evol. Trends Pl.4: 85–98.
Dupont, Y. L., Kato, M., 1998a: Sex ratio and flowering in six sympatric dioecious shrub species ofLindera (Lauraceae). — Nordic J. Bot. (in press).
- - 1998b: Pollination biology of six sympatric dioecious species ofLindera (Lauraceae). — Nordic J. Bot. (in press).
Feinsinger, P., Wolfe, J. A., Swarm, L. A., 1982: Island ecology: reduced hummingbird diversity and the pollination biology of plants, Trinidad, Tobago, and West Indies. — Ecology63: 494–506.
Fowler, J., Cohen, L., 1990: Practical statistics for field biology. — Chichester: Wiley.
Fox, J. F., 1985: Incidence of dioecy in relation to growth form, pollination and dispersal. — Oecologia67: 244–249.
Freeman, D. C., McArthur, E. D., Harper, K. T., 1984: The adaptive significance of sexual lability in plants usingAtriplex canescens as a principal example. — Ann. Missouri Bot. Gard.71: 265–277.
—,Doust, J. L., El-Keblawy, A., Miglia, K. J., McArthur, E. D., 1997: Sexual specialization and inbreeding avoidance in the evolution of dioecy. — Bot. Rev.63: 65–92.
Guitian, P., 1995: Reproductive biology ofRhamnus legionensis Roth., a dioecious species endemic to the northwest Iberian Peninsula. — Flora190: 345–352.
Heywood, V. H., Moore, D. M., Richardson, I. B. K., Stearn, W. T., (Eds), 1993: Flowering plants of the world. — London: Batsford.
House, S. M., 1989: Pollen movement to flowering canopies of pistillate individuals of three rain forest tree species in tropical Australia. — Austral. J. Ecol.14: 77–94.
Kato, M., Nagamasu, H., 1995: Dioecy in the endemic genusDendrocacalia (Compositae) on the Bonin (Ogasawara) Islands. — J. Pl. Res.108: 443–450.
Kevan, P. G., Longair, R. W., Gadawski, R. M., 1985: Dioecy and pollen dimorphism inVitis riparia (Vitaceae). — Canad. J. Bot.63: 2263–2267.
Knowles, B., Beveridge, A. E., 1982: Biological flora of New Zealand 9.Beilschmidia tawa (A. Cunn.)Benth. etHook. F. exKirk (Lauraceae). — New Zealand J. Bot.20: 37–54.
Kubitzki, K., Kurz, H., 1984: Synchronized dichogamy and dioecy in neotropicalLauraceae. — Pl. Syst. Evol.147: 253–266.
Lloyd, D. G., 1985: Progress in understanding the natural history of New Zealand plants. — New Zealand J. Bot.23: 707–722.
Lughadha, E. N., Proenca, C., 1996: A survey of the reproductive biology of theMyrtoideae (Myrtaceae). — Ann. Missouri Bot. Gard.83: 480–503.
Mabberley, D. J., 1987: The plant-book. — Cambridge University Press.
Olesen, J. M., 1985: The Macaronesian bird-flower element and its relation to bird and bee opportunists. — Bot. J. Linn. Soc.91: 395–414.
—, 1988: Floral biology of the CanarianEchium wildpretii — a bird-flower or a water resource to desert bees? — Acta Bot. Neerl.37: 509–513.
—, 1992: How do plants reproduce on their range margin? — InThanos, C. A., (Ed.): Plantanimal interactions in mediterranean-type ecosystems, pp. 217–222. — Athens: Univ. Athens.
—,Warncke, E., 1989a: Predation and transfer of pollen in a population ofSaxifraga hirculus L. — Holarc. Ecol.12: 87–95.
—, —, 1989b: Temporal changes in pollen flow and neighbourhood structure in a population ofSaxifraga hirculus L. — Oecologia79: 205–211.
—,Forfang, A.-S., Báez, M., 1998: Stress-induced male sterility and mixed mating in the island plantCedronella canariensis (Lamiaceae). — Pl. Syst. Evol.212: 159–176.
Primack, R. B., 1978: Variability in New Zealand montane and alpine pollinator assemblages. — New Zealand J. Ecol.1: 66–73.
—, 1985: Sex ratio and sexual constancy in spicebush (Lindera benzoin). — Rhodora87: 305–308.
Renner, S. S., Rickleffs, R. E., 1995: Dioecy and its correlates in the flowering plants. — Amer. J. Bot.82: 596–606.
Rohwer, J. G., 1993:Lauraceae. — InKubitzki, K., (Ed.): The families and genera of vascular plants. — Berlin, Heidelberg, New York: Springer.
Sakai, A. K., Karoly, K., Weller, S. G., 1989: Inbreeding depression inSchiedea globosa andSchiedea salicaria (Caryophyllaceae), subdioecious and gynodioecious Hawaiian (USA) species. — Amer. J. Bot.76: 437–444.
Schlessman, M. A., Lowry, P. P., Lloyd, D. G., 1990: Functional dioecism in the New Caledonian endemicPolyscias pancheri (Araliaceae). — Biotropica22: 133–139.
Siegel, S., Castellan, N. J., 1988: Nonparametric statistics for the behavioral sciences. — New York: McGraw-Hill.
Stephenson, A. G., 1981: Flower and fruit abortion: Proximate causes and ultimate functions. — Annual Rev. Ecol. Syst.12: 253–279.
Thomas, S. C., LaFrankie, J. V., 1993: Sex, size, and interyear variation in flowering among dioecious trees of the Malayan rain forest. — Ecology74: 1529–1537.
Thomson, J. D., Brunet, J., 1992: Hypotheses for the evolution of dioecy in seed plants. — TREE5: 11–16.
Vogel, S., Westerkamp, C., Thiel, B., Gessner, K., 1984: Ornithophilie auf den Canarischen Inseln. — Pl. Syst. Evol.146: 225–248.
Westerkamp, C., 1990: Blumenvögel auf den Islas Canarias. — Trochilus11: 79–81.
Wheelwright, N. T., 1985: Competition for dispersers, and the timing of flowering and fruiting in a guild of tropical trees. — Oikos44: 465–477.
—, 1986: A seven-year study of individual variation in fruit production in tropical bird-dispersed tree species in the familyLauraceae. — InEstrada, A., Fleming, T. H., (Eds): Frugivores and seed dispersal, pp. 19–35. — Dordrecht: Junk.
—,Bruneau, A., 1992: Population sex ratios and spatial distribution ofOcotea tenera (Lauraceae) trees in a tropical forest. — J. Ecol.80: 425–432.
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Forfang, AS., Olesen, J.M. Male-biased sex ratio and promiscuous pollination in the dioecious island treeLaurus azorica (Lauraceae). Pl Syst Evol 212, 143–157 (1998). https://doi.org/10.1007/BF01089736
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DOI: https://doi.org/10.1007/BF01089736