Abstract
Vegetative reproduction is a very common alternative by which plants can contribute to the next generations. There are many considerations predicting which mode of reproduction, vegetative or sexual, should be favored and numerous experimental studies to verify them. However, the results are inconsistent especially when the effect of plant density is considered. I apply here a dynamic optimization model to predict the rate of vegetative and sexual reproduction in plants as a response to changes in the local plant density. The population is assumed to occupy a heterogeneous environment consisting of patches in which growth and reproduction of plants are possible and unfavorable space between them. As the environment is globally stable, the seeds, which can disperse without restriction, exhibit a constant recruitment rate. The ramets are assumed to settle only within the patch of the mother plant. The rate of ramet production effects local density, which in turn determines ramet recruitment. The optimal strategy maximizes the expected lifetime genetic contribution, realized via both vegetative and sexual reproduction. The solutions obtained under these assumptions are dualistic. The model predicts that different approaches applied in studying the effect of ramet density should give opposite outcomes. When the comparison is between patches in natural populations, a positive relationship between relative ramet allocation and density is expected. When the density is experimentally manipulated or its effect is analyzed across different successional stages, a negative relationship should be found. The results seem to be confirmed by empirical studies.
Similar content being viewed by others
References
Abrahamson, W.G. (1975) Reproductive strategies in dewberries. Ecology 56, 721-726.
Abrahamson, W.G. (1979) A comment on vegetative and seed reproduction in plants. Evolution 33, 517-519.
Abrahamson, W.G. (1980) Demography and vegetative reproduction. In O.T. Solbrig (ed.) Demography and Evolution in Plant Populations. Blackwell Scientific Publication, Oxford, England, pp. 89-106.
Armstrong, R.A. (1982) A quantitative theory of reproductive e.ort in rhizomatous perennial plants. Ecology 63, 679-686.
Armstrong, R.A. (1984) On the quantitative theory of reproductive e.ort in clonal plants: Refinements of theory, with evidence from goldenrods and mayapples. Oecologia 63, 410-417.
Bierzychudek, P. (1982) Life histories and demography of shade-tolerant temperate forest herbs: a review. New Phytol. 90, 757-776.
Caswell, H. (1982) Optimal life histories and the maximization of reproductive value: a general theorem for complex life cycles. Ecology 63, 1218-1222.
Eriksson, O. (1989) Seedling dynamics and life history in clonal plants. Oikos 55, 231-266.
Eriksson, O. (1996) Regional dynamics of plants: a review of evidence for remnant, source-sink and metapopulations. Oikos 77, 248-258.
Fagerström, T. (1992) The meristem-meristem cycle as a basis for defining fitness in clonal plants. Oikos 63, 449-452.
Gadgil, M. and Solbrig, O.T. (1972) The concept of r-and K-selection: evidence from wild flowers and some theoretical considerations. Am. Nat. 106, 14-31.
Gardner, S.N. and Mangel, M. (1999) Modelling investments in seeds, clonal offspring, and translocation in a clonal plant. Ecology 80, 1202-1220.
Kimmerer, R.W. (1991) Reproductive ecology of Tetraphis pellucida, I. Population density and reproductive mode. Bryologist 94, 255-260.
Loehle, C. (1987) Partitioning of reproductive effort in clonal plants: a benefit-cost model. Oikos 49, 199-208.
Mangel, M. and Clark, C.W. (1988) Dynamic Modeling in Behavioral Ecology. Princeton University Press, Princeton, New Jersey.
Newell, S.J. and Tramer, E.J. (1978) Reproductive strategies in herbaceous plant communities during succession. Ecology 59, 228-234.
Nishitani, S. and Kimura, M. (1993) Resource allocation to sexual and vegetative reproduction in a forest herb Syneilesis palmata (Compositae). Ecol. Res. 8, 173-183.
Ogden, J. (1974) The reproductive strategy of higher plants, II: the reproductive strategy of Tussilago farfara L. J. Ecol. 62, 291-324.
Olejniczak, P. (2001) Evolutionarily stable allocation to vegetative and sexual reproduction in plants. Oikos 95, 156-160.
Pedersen, B. and Tuomi, J. (1995) Hierarchical selection and fitness in modular organisms. Oikos 73, 167-180.
Pontriagin, L.S., Boltianskii, V.G., Gakrelidze, R. and Maschenko, E.F. (1962) The Mathematical Theory of Optimal Processes. Wiley-Interscience, New York.
Prati, D. and Schmid, B. (2000) Genetic differentiation of life-history traits within populations of the clonal plant Ranunculus reptans. Oikos 90, 442-456.
Reekie, E.G. (1991) Cost of seed versus rhizome production Agropyron repens. Can. J. Bot. 69, 2678-2683.
Sackville Hamilton, N.R., Schmid, B. and Harper, J.L. (1987) Life-history concepts and the population biology of clonal organisms. Proc. R. Soc. Lond. B. 232, 35-57.
Schaffer, W.M. (1974) The evolution of optimal reproductive strategies: the effect of age structure. Ecology 55, 291-303.
Schaffer, W.M. and Gadgil, M. (1975) Selection for optimal life histories in plants. In M.L. Cody and J.M. Diamond (eds) Ecology and Evolution of Communities. Belknap Press, Cambridge, Massachusetts, pp. 142-157.
Silvertown, J.W. (1987) Plant Population Ecology. Longman Scientific & Technical, Essex, England.
Tuomi, J. and Vuorisalo, T. (1989) What are the units of selection in modular organisms? Oikos 54, 227-233.
Watt, A.S. (1947) Pattern and process in plant community. J. Ecol. 35, 1-22.
Wikberg, S. (1995) Fitness in clonal plants. Oikos 72, 293-297.
Williams, G.C. (1975) Sex and Evolution. Princeton University Press, Princeton, New Jersey.
Winkler, E. and Fischer, M. (1999) Two fitness measures for clonal plants and the importance of spatial aspects. Plant Ecol. 141, 191-199.
Winkler, E. and Fischer, M. (2002) The role of vegetative spread and seed dispersal for optimal life histories of clonal plants: a simulation study. Evol. Ecol. 15, 281-301.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Olejniczak, P. Optimal allocation to vegetative and sexual reproduction in plants: the effect of ramet density. Evolutionary Ecology 17, 265–275 (2003). https://doi.org/10.1023/A:1025572713483
Issue Date:
DOI: https://doi.org/10.1023/A:1025572713483