Summary
The influence of risk of herbivory and its variation in time on the optimal defence strategy in plants is analysed by a simple optimization model. We contrast two possible defence strategies; a constitutive defence with an invariant defence level in time and an idealized induced defence, that is, a strategy that adjusts the defence level to the prevailing risk of herbivory. We also take into account effects of the efficiency of the defence. If there is no variation in risk of herbivory over years, constitutive and induced defence should have the same expected optimal defence level and both strategies are equally fit. The optimal defence level increases as the maximum fecundity and the adult to juvenile survival ratio of the plants both increase. If the risk of herbivory varies stochastically, the expected optimal level of the constitutive defence is either increased or unaffected by the variation, whereas the induced defence strategy may result in both higher or lower expected optimal defence levels as variance increases. This outcome is dependent on the mean risk of herbivory. It also depends on the defence efficiency, i.e. the shape (convex, concave or linear) of the defence function that relates the probability of survival if encountered by a herbivore to defence level. Thus, the defence level of plants interacting with variable herbivore populations cannot be unambiguously predicted unless the defence strategy (constitutive or induced), mean risk of herbivory, the form of the defence function and plant life history are known.
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References
Augner, M., Fagerström, T. and Tuomi, J. (1991) Competition, defense and games between plants.Behav. Ecol. Sociobiol. 29 231–4.
Briggs, M.A. and Schultz, J.C. (1990) Chemical defense production inLotus corniculatus L. II. Trade-offs among growth, reproduction and defense.Oecologia 83 32–7.
Bryant, J.P., Tahvanainen, J., Sulkinoja, M., Julkunen-Tiitto, R., Reichardt, P. and Green, T. (1989) Biogeographic evidence for the evolution of chemical defense by boreal birch and willow against mammalian browsing.Am. Nat. 134 20–34.
Chew, F.S. and Courtney, S.P. (1991) Plant apparency and evolutionary escape from insect herbivory.Am. Nat. 138 729–50.
Clark, C.W. and Harvell, C.D. (1992) Inducible defenses and the allocation of resources: a minimal model.Am. Nat. 139 521–39.
Coley, P.D. and Aide, T.M. (1991) Comparison of herbivory and plant defenses in temperate and tropical broad-leaved forests. InPlant—animal interactions: evolutionary ecology in tropical and temperate regions (P.W. Price, T.M. Lewinsohn, G.W. Fernandez and W.W. Benson, eds), pp. 25–49. John Wiley & Sons, Inc., New York.
Coley, P.D., Bryant, J.P. and Chapin, F.S., III (1985) Resource availability and plant antiherbivore defense.Science 230 895–9.
Crawley, M.J. (1988) Herbivores and plant population dynamics. InPlant population ecology (A.J. Davy, M.J. Hutchings and A.R. Watkinson, eds), pp. 367–92. Blackwell Scientific Publications, Oxford.
Edelstein-Keshet, L. and Rausher, M.D. (1989) The effects of inducible plant defenses on herbivore populations. 1. Mobile herbivores in continuous time.Am. Nat. 133 787–810.
Fagerström, T., Larsson, S. and Tenow, O. (1987) On optimal defense in plants.Funct. Ecol. 1 73–81.
Feeny, P.P. (1976) Plant apparency and chemical defense. Biochemical interactions between plants and insects. InRecent advances in phytochemistry (J.W. Wallace and R.L. Mansell, eds) Vol. 10, pp. 1–40. Plenum Publishing, New York.
Gulmon, S.L. and Mooney, H.A. (1986) Costs of defense and their effects on plant productivity. InOn the economy of plant form and function (T.J. Givnish, ed.), pp. 681–98. Cambridge University Press, Cambridge.
Harper, J.L. (1977)Population Biology of Plants. Academic Press, Oxford.
Harvell, C.D. (1990) The ecology and evolution of inducible defenses.Q. Rev. Biol. 65 323–40.
Haukioja, E. and Neuvonen, S. (1985). Induced long-term resistance of birch foliage against defoliators: defensive or incidental?Ecology 66 1303–8.
Havel, J.E. (1987) Predator-induced defenses: a review. InPredation: direct and indirect impacts on aquatic communities (W.C. Kerfoot and A. Sih, eds), pp. 263–78. University Press of New England, Hanover, NH.
Herms, D.A. and Mattson, W.J. (1992) The dilemma of plants: to grow or defend.Q. Rev. Biol. 67 283–335.
Karban, R. and Myers, J.H. (1989) Induced plant responses to herbivory.Ann. Rev. Ecol. Syst. 20 331–48.
Loehle, C. (1988) Tree life history strategies: the role of defenses.Can. J. Forest Res. 18 209–22.
Louda, S.M., Keeler, K.H. and Holt, R.D. (1990) Herbivore influences on plant performance and competitive interactions. InPerspectives on plant competition (J.B. Grace and D. Tilman, eds), pp. 413–44. Academic Press, San Diego.
Lubchenco, J. and Cubit, J. (1980) Heteromorphic life histories of certain marine algae as adaptations to variations in herbivory.Ecology 61 676–87.
Lubchenco, J. and Gains, S.D. (1981) A unified approach to marine plant-herbivore interactions. I. Populations and communities.Ann. Rev. Ecol. Syst. 12 405–37.
Lundberg, P. and Åström, M. (1990) Low nutritive quality as a defense against optimally foraging herbivores.Am. Nat. 135, 547–62.
Oksanen, L. (1990) Predation, herbivory, and plant strategies along gradients of primary productivity. InPerspectives on plant competition (J.B. Grace and D. Tilman, eds), pp. 445–74. Academic Press, San Diego.
Rhoades, D.F. (1979) Evolution of plant chemical defense against herbivores. InHerbivores. Their interactions with secondary plant metabolites (G.A. Rosenthal and D.H. Janzen, eds), pp. 3–54. Academic Press, New York.
Rhoades, D.F. and Cates R.G., (1976) Toward a general theory of plant antiherbivore chemistry. InBiochemical interactions between plants and insects. Recent advances in phytochemistry (J.W. Wallace and R. Mansell, eds), Vol. 10, pp. 205–38, Plenum Publishing, New York.
Riessen, H.P. (1992) Cost—benefit model for the induction of an antipredator defense.Am. Nat. 140 349–62.
Schaffer, W.M. (1974) Optimal reproductive effort in fluctuating environments.Am. Nat. 108 783–90.
Simms, E.L. (1992) Costs of plant resistance to herbivory. InPlant resistance to herbivores and pathogenes. Ecology, evolution and genetics (R.S. Fritz and E.L. Simms, eds), pp. 392–425. University of Chicago Press, Chicago.
Welsh, A.H., Peterson, A. T and Altmann, S.A. (1988) The fallacy of averages.Am. Nat. 132 277–88.
Zangerl, A.R. and Bazzaz, F.A. (1992) Theory and pattern in plant defense allocation.Am. Nat. 132 363–91.
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Åström, M., Lundberg, P. Plant defence and stochastic risk of herbivory. Evol Ecol 8, 288–298 (1994). https://doi.org/10.1007/BF01238279
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DOI: https://doi.org/10.1007/BF01238279