Skip to main content
Log in

Local sex-ratio dynamics: a model for the dioecious liverwort Marchantia inflexa

  • Published:
Evolutionary Ecology Aims and scope Submit manuscript

Abstract

In many dioecious bryophyte species, population sex ratios range from all female to all male. The focal species of the present study, the liverwort Marchantia inflexa, forms patches on rock and bark surfaces, and these differ widely in sex ratio at a rainforest field site in Trinidad. This analysis – to our knowledge the first modeling study of sex-ratio dynamics in a dioecious clonal organism – addresses abundances of male and female M. inflexa through time within an individual patch. We represent the life history of this species using seven different stages (non-reproductive, asexually reproductive, sexually reproductive males, non-reproductive, asexually reproductive, unfertilized and fertilized sexual females) and express their dynamics using ordinary differential equations. Some of the stages become more abundant as thalli extend over the substrate and may overgrow each other to capture space. Our simple representation of dynamics within the patch failed to stabilize the sex ratio: females gradually eliminated males at low to moderate disturbance frequency and males eliminated females at high disturbance frequency. This pattern did not hinge on whether sexual propagules could germinate within the patch, but asexual reproduction (via gemmae dispersed within the patch) played an important role. This suggests that the maintenance of sex in these populations may hinge on metapopulation structure and dynamics. Though sexual reproduction appears to be unimportant within patches, spores provide the primary means of recolonizing patches eliminated by large-scale disturbances. We found that shortly after the patch was fully occupied, the production of these wind-dispersed spores was maximized, but spore production declined thereafter as the sex ratio became increasingly biased toward one sex or the other. Much additional modeling and empirical work is needed to link within-patch dynamics across patches and account for dynamics at the metapopulation level.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Anderson, F.S. (1961) Effect of density on animal sex ratio. Oikos 12, 1-15.

    Google Scholar 

  • Barrett, J.P. and Silander, J.A. (1992) Seedling recruitment limitation in white clover (Trifolium repens: Leguminoseae). Am. J. Bot. 79, 643-649.

    Google Scholar 

  • Bierzychudek, P. and Eckhart, V. (1988) Spatial segregation of the sexes of dioecious plants. Am. Nat. 132, 34-43.

    Google Scholar 

  • Bischler, H. (1984) Marchantia L. The New World species. Bryophytorum Bibliotheca 26.

  • Bischler, H. (1986) Marchantia polymorpha L. s. lat. Kayotype analysis. J. Hattori Bot. Lab. 60, 105-117.

    Google Scholar 

  • Bolker, B.M. and Pacala, S.W. (1999) Spatial moment equation for plant competition: understanding spatial strategies and the advantages of short dispersal. Am. Nat. 153, 575-602.

    Google Scholar 

  • Bowker, M.A., Stark, L.R., McLetchie, D.N. and Mishler, B.D. (2000) Sex expression, skewed sex ratios, and microhabitat distribution in the dioecious desert moss Syntrichia caninervis (Pottiaceae). Am. J. Bot. 87, 517-526.

    Google Scholar 

  • Burdon, J.J. (1980) Intra-specific diversity in a natural population of Trifolium repens. J. Ecol. 68, 717-735.

    Google Scholar 

  • Caswell, H. (2000) Matrix Population Models. Sinauer Associates, Inc., Sunderland, MA, USA.

    Google Scholar 

  • Connell, J.H. (1978) Diversity in tropical rain forests and coral reefs. Science 199, 1302-1310.

    Google Scholar 

  • Crowley, P.H. and McLetchie, D.N. Tradeoffs and spatial life-history strategies in classical metapopulations. Am. Nat. 159, 190-208.

  • Darwin, C. (1877) The Different Forms of Flowers on Plants of the Same Species. Murray, London, UK.

    Google Scholar 

  • De Steven, D. (1989) Genet and ramet demography of Oenocarpus mapora mapora, a clonal palm of Panamanian tropical moist forest. J. Ecol. 77, 579-596.

    Google Scholar 

  • Durako, M.J. and Moffler, M.D. (1985) Observations on the reproductive ecology of Thalassia testudinum (Hydrocharitaceae): III. Spatial and temporal variations in reproductive patterns within a seagrass bed. Aquat. Bot. 22, 265-276.

    Google Scholar 

  • During, H.J. (1990) Clonal growth patterns among bryophytes. In J. van Groenendael and H. de Kroon (eds) Clonal Growth in Plants. SPB Academic Publishing, The Hague, The Netherlands, pp. 153-176.

    Google Scholar 

  • Ellstrand, N.C. and Roose, M.L. (1987) Patterns of genotype diversity in clonal plant species. Am. J. Bot. 74, 123-131.

    Google Scholar 

  • Eppley, S.M., Stanton, L.M. and Grossberg, R.K. (1998) Intrapopulational sex ratio variation in the salt grass Distichlis spicata. Am. Nat. 152, 659-670.

    Google Scholar 

  • Eriksson, O. (1993) Dynamics of genets in clonal plants. Trends Ecol. Evol. 8, 313-316.

    Google Scholar 

  • Escarre, J. and Houssard, C. (1991) Changes in sex ratio in experimental populations of Rumex acetosella. J. Ecol. 79, 379-387.

    Google Scholar 

  • Fahrig, L., Coffin, D.P., Lauenroth, W.K. and Shugart, H.H. (1994) The advantage of long-distance clonal spreading in highly disturbed habitats. Evol. Ecol. 8, 172-187.

    Google Scholar 

  • Falinski, J.B. (1980) Vegetation dynamics and sex structure of the populations of pioneer dioccious woody plants. Vegetatio 43, 23-38.

    Google Scholar 

  • Fisher, R.A. (1930) The Genetical Theory of Natural Selection. Oxford University Press, Oxford, UK.

    Google Scholar 

  • Ford, H. (1981) Competitive relationships amongst apomictic dandelions (Taraxacum). Bio. J. Linnean Soc. 15, 355-368.

    Google Scholar 

  • Grant, M.C. and Mitton, J.B. (1979) Elevational gradients in adult sex ratios and sexual differentiation in vegetative growth rates of Populus tremuloides Michx. Evolution 33, 914-918.

    Google Scholar 

  • Houssard, C., Thompson, J.D. and Escarre, J. (1994) Do the sex-related differences in response to environmental variation influence the sex-ratio in dioecious Rumex acetosella. Oikos 70, 80-90.

    Google Scholar 

  • Husband, B.C. and Barrett, S.C.H. (1996) A metapopulation perspective in plant population biology. J. Ecol. 84, 461-469.

    Google Scholar 

  • Korpelainen, H. (1992) Patterns of resource allocation in male and female plants of Rumex acetosa and R. acetosella. Oecologia 89, 133-139.

    Google Scholar 

  • Korpelainen, H. (1994) Sex ratios and resource allocation among sexually reproducing plants of Rubus chamaemorus. Ann. Bot. 74, 627-632.

    Google Scholar 

  • Lloyd, D.G. and Webb, C.J. (1977) Secondary sex characters in plants. The Botanical Rev. 43, 177-216.

    Google Scholar 

  • Longton, R.E. (1990) Sexual reproduction in bryophytes in relation to physical factors of the environment. In R.N. Chopra and S.C. Bhatla (eds) Bryophyte Development: Physiology and Biochemistry, CRC Press, Boca Raton, FL. pp. 139-166.

    Google Scholar 

  • Longton, R.E. and Greene, S.W. (1969) The growth and reproductive cycle of Pleurozium schreberi (Brit.). Mitt. Ann. Bot. 33, 83-105.

    Google Scholar 

  • Longton, R.E. and Greene, S.W. (1979) Experimental studies of growth and reproduction in the moss Pleurozium schreberi (Brid.). Mitt. Trans. Brit. Bryol. Soc. 10, 321-338.

    Google Scholar 

  • Longton, R.E. and Schuster, R.M. (1983) Reproductive biology. In R.M. Schuster (ed.) New Manual of Bryology. Hattori Botanical Laboratory, Nichinan, Japan. pp. 386-462.

    Google Scholar 

  • Lovett Doust, L. (1981) Population dynamics and local specialization in a clonal perennial (Ranunculus repens). I. The dynamics of ramets in contrasting habitats. J. Ecol. 69, 743-755.

    Google Scholar 

  • Lovett Doust, J. and Lovett Doust, L. (1988) Modules of production and reproduction in a dioecious clonal shrub, Rhus typhina. Ecology 69, 741-750.

    Google Scholar 

  • McLetchie, D.N. (1992) Sex ratio from germination through maturity and its reproductive consequences in the liverwort Sphaerocarpos texanus. Oecologia 92, 273-278.

    Google Scholar 

  • McLetchie, D.N. (1996) Sperm limitation and genetic effects on fecundity in the dioecious liverwort Sphaerocarpos texanus. Sexual Plant Reprod. 9, 87-92.

    Google Scholar 

  • McLetchie, D.N. and Puterbaugh, M.N. (2000) Population sex ratios, sex-specific clonal traits and tradeoffs among these traits in the liverwort, Marchantia inflexa. Oikos 90, 227-237.

    Google Scholar 

  • Miles, C.J., Odu, E.A. and Longton, R.E. (1989) Phenological studies on British mosses. Trans. Brit. Bryol. Soc. 15, 607-621.

    Google Scholar 

  • Newton, M.E. (1972) Sex-ratio differences in Mnium hornum Hedw. and M. undulatum Sw. in relation to spore germination and vegetative regeneration. Ann. Bot. 26, 163-178.

    Google Scholar 

  • Newton, A.E. and Mishler, B.D. (1994) The evolutionary significance of asexual reproduction in mosses. J. Hattori Bot. Lab. 76, 127-145.

    Google Scholar 

  • Pedersen, B., Hanslin, H.M. and Bakken, S. (2001) Testing for positive density-dependent performance in four bryophyte species. Ecology 82, 70-88.

    Google Scholar 

  • Popp, J.W. and Reinartz, J.A. (1988) Sexual dimorphism in biomass allocation and clonal growth of Xanthoxylum americanum. Am. J. Bot. 75, 1732-1741.

    Google Scholar 

  • Putwain, P.D. and Harper, J.L. (1972) Studies in the dynamics of plant populations. V. Mechanisms governing the sex ratio in Rumex acetosa and R. acetosella. J. Ecol. 60, 113-129.

    Google Scholar 

  • Ranta, E., Kaitala, V. and Lindstrom, J. (1999) Sex in space: population dynamic consequences. Proc. R. Soc. Lond. B 266, 1155-1160.

    Google Scholar 

  • Renzaglia, K.S. and McFarland, K.D. (1999) Antheridial plants of Megaceros aenigmaticus in the southern Appalachians: anatomy, ultrastructure and population distribution. Haussknechtia Beiheft 9 (Riclef Grolle-Festschrift), 307-316.

    Google Scholar 

  • Rydgren, R. and Økland, R.H. Life cycle graphs and matrix modelling of bryophyte populations. Lindbergia (in press).

  • Sakai, A.K. and Burris, T.A. (1985) Growth in male and female aspen clones: a twenty-five-year longitudinal study. Ecology 66, 1921-1927.

    Google Scholar 

  • Schmid, B. and Harper, J.L. (1985) Clonal growth in grassland perennials. I. Density and pattern-dependent competition between plants with different growth forms. J. Ecol. 73, 793-808.

    Google Scholar 

  • Schuster, R.M. (1992) Volume VI. The Hepaticae and Anthocerotae of North America. Field Museum of Natural History, Chicago, IL.

    Google Scholar 

  • Sebens, K.P. and Thorne, B.L. (1985) Coexistence of clones, clonal diversity, and the effects of disturbance. In J.B.C. Jackson, L.W. Buss and R.E. Cook (eds) Population Biology and Evolution of Clonal Organisms. Yale University Press, New Haven, CT. pp. 357-398.

    Google Scholar 

  • Shaw, A.J. and Beer-Samuel, C. (1999) Life history variation in gametophyte populations of the moss Ceratodon purpureus (Ditrichaceae). Am. J. Bot. 86, 512-521.

    Google Scholar 

  • Shaw, A.J. and Gaughan, J.F. (1993) Control of sex ratios in haploid populations of the moss Ceratodon purpureus. Am. J. Bot. 80, 584-591.

    Google Scholar 

  • Smith, A.J.E. (1982) Bryophyte Ecology. Chapman and Hall, London, UK.

    Google Scholar 

  • Smith, D.K. and Davison, P.G. (1993) Antheridia and sporophytes in Takakia ceratophylla (Mitt.) Grolle: evidence for reclassification among the mosses. J. Hattori Bot. Lab. 73, 271-363.

    Google Scholar 

  • Sousa, W.P. (1979) Disturbance in marine intertidal boulder fields: the nonequilibrium maintenance of species diversity. Ecology 60, 1225-1239.

    Google Scholar 

  • Stark, L.R., Mishler, B.D. and McLetchie, D.N. (2000) The cost of realized sexual reproduction: assessing patterns of reproductive allocation and sporophyte abortion in a desert moss. Am. J. Bot. 87, 1599-1608.

    Google Scholar 

  • Stoll, P. and Prati, D. (2001) Intraspecific aggregation alters competitive interactions in experimental plant communities. Ecology 82, 319-327.

    Google Scholar 

  • Une, K. (1984) A field observation on the reproductive mode in Marchantia polymorpha L. Hikobia 9, 15-18.

    Google Scholar 

  • Voth, P.D. and Hamner, K.C. (1940) Responses of Marchantia polymorpha to nutrient supply and photoperiod. Bot. Gazette 102, 169-205.

    Google Scholar 

  • Wildish, D.J. (1976) A selected bibliography of invertebrate sex ratio data. Fish. Res. Bd. Can. Tech. Rep., 630.

  • Williams, S.L. (1995) Surgrass (Phyllospadix torreyi) reproduction: reproductive phenology, resource allocation, and male rarity. Ecology 76, 1953-1970.

    Google Scholar 

  • Willson, M.J. (1983) Plant Reproductive Ecology. John Wiley & Sons, New York, NY, USA.

    Google Scholar 

  • Wyatt, R. (1977) Spatial pattern and gamete dispersal distances in Atrichum angustatum, a dioecious moss. The Bryol 80, 284-291.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

McLetchie, D.N., García-Ramos, G. & Crowley, P.H. Local sex-ratio dynamics: a model for the dioecious liverwort Marchantia inflexa . Evolutionary Ecology 15, 231–254 (2001). https://doi.org/10.1023/A:1016000613291

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1016000613291

Navigation