Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-24T03:10:49.800Z Has data issue: false hasContentIssue false

Effects of Defoliation on Competitive Interactions between Invasive Crofton Weed (Eupatorium adenophorum) and its Native Neighbors: Implication for Biocontrol

Published online by Cambridge University Press:  20 January 2017

Li Zhu
Affiliation:
Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China
Weiguo Sang*
Affiliation:
Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China
*
Corresponding author's E-mail: [email protected]

Abstract

Defoliation can affect plant competition in at least two ways: negative effects on the performance of defoliated plants and positive effects on nondefoliated plants due to neighbor defoliation. It has been suggested that these effects can alter competitive relations between plants, and this study was designed to test this in an experiment using Crofton weed as the invasive category, and its two neighbors Japanese brome and Dichrocephala as the native category. The plants were grown from seed and potted either singly or in pairs. The pairs consisted either of two conspecific plants (same pairs) or of one plant of each category (mixed pairs). Randomly preselected plants were defoliated twice in the growing season, at 9 wk and again at 5 wk before final biomass sampling. Competition reduced growth by 51 to 78%, with the plants of the native category consistently more affected than the invasive category. When grown singly, Crofton weed grew larger (average 67%) than the native species. As compared with plants grown singly, Crofton weed plants grown in mixed pairs were 40% smaller. The corresponding data for the native species were 78% smaller for Japanese brome and 73% smaller for Dichrocephala. The effects of neighbor defoliation differed among categories and competition. All the nondefoliated plants grown singly were larger than plants grown with a defoliated conspecific neighbor. For the corresponding relationship in mixed pairs, the native plants grown singly were significantly larger than the same native species grown together with a defoliated, invasive neighbor. Defoliation of Crofton weed reduced the growth of native neighbors and increased negative competitive effects on native plants. For the invasive species, however, Crofton weed plants grown in mixed pairs with neighbor defoliation compensated fully for the competitive effects, i.e., they were not significantly different from nondefoliated plants grown singly. Consequently, the effects of defoliation on competition between invasive Crofton weed and its native neighbors may depend on the ability to undertake compensatory growth, and probably on the allelopathic exudation of Crofton weed to herbivory. Our data suggest that herbivory by biocontrols can make an already superior competitor even stronger, especially if the biocontrol agent does not effectively damage or kill the target plant. Owing to complex interactions between competition and defoliation, the indirect effects of herbivory may be more complicated than currently conceived, and understanding the indirect effects of biocontrol agents before their release is crucial.

Type
Weed Management
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Baldwin, I. T. 1990. Herbivory simulations in ecological research. Trends Ecol. Evol. 5:9193.Google Scholar
Baldwin, I. T. and Schultz, J. C. 1983. Rapid changes in tree leaf chemistry induced by damage: evidence for communication between plants. Science. 221:277279.Google Scholar
Bentley, S. and Whittaker, J. B. 1979. Effects of grazing by a chrysomelid beetle, Gastrophysa viridula, on competition between Rumex obtusifolia and Rumex crispus . J. Ecol. 67:7990.Google Scholar
Blossey, B. and Notzold, R. 1995. Evolution of increased competitive ability in invasive nonindigenous plants: a hypothesis. J. Ecol. 83:887889.Google Scholar
Broughton, S. 2003. Effect of artificial defoliation on growth and biomass of Lantana camara L. (Verbenaceae). Plant Protect. Q. 18:110115.Google Scholar
Bryant, J. P., Tuomi, J., and Niemelä, P. 1988. Environmental constraint of constitutive and long-term inducible defenses in woody plants. in Spencer, K.C., ed. Chemical Mediation of Coevolution. New York Academic. 367389.Google Scholar
Callaway, R. M., DeLuca, T., and Belliveau, W. M. 1999. Herbivores used for biological control may increase the competitive ability of the noxious weed Centaurea maculosa . Ecology. 80:11961201.Google Scholar
Capinera, J. L. and Roltsch, W. J. 1980. Response of wheat seedlings to actual and simulated migratory grasshopper defoliation. J. Econ. Entomol. 73:258261.Google Scholar
Colpetzer, K., Hough-Goldstein, J., Harkins, K. R., and Smith, M. T. 2004. Feeding and oviposition behaviour of Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) and its predicted effectiveness as a biological control agent for Polygonum perfoliatum L. (Polygonales: Polygonaceae). Environ. Entomol. 33:990996.Google Scholar
Crawley, M. J. 1986. Plant Ecology. Oxford, UK Blackwell.Google Scholar
DeWalt, S. J., Denslow, J. S., and Ickes, K. 2004. Natural-enemy release facilitates habitat expansion of the invasive tropical shrub Clidemia hirta. Ecology. 85:471483.Google Scholar
Farmer, E. E. 2001. Surface-to-air signals. Nature. 411:854856.Google Scholar
Fowler, N. L. and Rausher, M. D. 1985. Joint effects of competitors and herbivores on growth and reproduction in Aristolochia reticulata. Ecology. 66:15801587.Google Scholar
Gelbard, J. L. and Belnap, J. 2003. Roads as conduits for exotic plant invasions in a semiarid landscape. Conserv. Biol. 17:420432.Google Scholar
Grace, J. B. and Tilman, D. 1990. Perspectives on plant competition. San Diego, CA Academic.Google Scholar
Harper, J. L. 1977. Population biology of plants. London, England Academic Press.Google Scholar
Hjältén, J. 2004. Simulating herbivory: problems and possibilities. in Weisser, W.W. and Siemann, E., eds. Ecological Studies, Vol. 173: Insects and Ecosystem Function. Berlin Springer-Verlag. 243255.Google Scholar
Keane, R. and Crawley, M. J. 2002. Exotic plant invasions and the enemy release hypothesis. Trends Ecol. Evol. 17:164170.Google Scholar
Lee, T. D. and Bazzaz, F. A. 1980. Effects of defoliation and competition on growth and reproduction in the annual plant Abutilon theophrasti . J. Ecol. 68:813821.Google Scholar
Lehtil, K. and Boalt, E. 2004. The use and usefulness of artificial herbivory in plant-herbivore studies. in: Weisser, W.W. and Siemann, E., eds. Ecological Studies, Insects and Ecosystem Function. Volume 173. Berlin Springer-Verlag. 257275.Google Scholar
Maron, J. L. and Vila, M. 2001. When do herbivores affect plant invasion? Evidence for the natural enemies and biotic resistance hypotheses. Oikos. 95:361373.Google Scholar
Massey, F. P., Massey, K., Press, M. C., and Hartley, S. E. 2006. Neighbourhood composition determines growth, architecture and herbivory in tropical rain forest tree seedlings. J. Ecol. 94:646655.Google Scholar
McEvoy, P. B. 2002. Insect–plant interactions on a planet of weeds. Entomol. Exp. Appl. 104:165179.Google Scholar
McEvoy, P. B., Cox, C. S., and Coombs, E. M. 1991. Successful biological control of ragwort Senecio jacobaea, by introduced insects in Oregon. Ecol. Appl. 1:430442.Google Scholar
McNaughton, S. J. 1983. Compensatory plant growth as a response to herbivory. Oikos. 40:329336.Google Scholar
Montgomery, S. C. 1984. Design and analysis of experiments. 2nd ed. New York John Wiley and Sons. 117118.Google Scholar
Paige, K. N. 1992. Overcompensation in response to mammalian herbivory: from mutualistic to antagonistic interactions. Ecology. 73:20762085.Google Scholar
Pimentel, D. E. 2002. Biological Invasions: Economic and Environmental Costs of Alien Plant, Animal, and Microbe Species. Boca Raton, FL CRC Press.Google Scholar
Rai, J. P. N. and Tripathi, R. S. 1985. Effects of herbivory by the slug, Mariaella dussumieri, and certain insects on growth and competitive success of two sympatric annual weeds. Agr. Ecosyst. Environ. 13:125137.Google Scholar
Rogers, W. E. and Siemann, E. 2002. Effects of simulated herbivory and resource availability on native and invasive exotic tree seedlings. Basic Appl. Ecol. 3:297307.Google Scholar
Shea, K. and Chesson, P. 2002. Community ecology theory as a framework for biological invasions. Trends Ecol. Evol. 17:170176.Google Scholar
Siemens, D., Garner, S., Mitchell-Olds, T., and Callaway, R. M. 2002. The cost of defense in the context of competition. Brassica rapa may grow and defend. Ecology. 83:505517.Google Scholar
SPSS 1999. SPSS for Windows. Release 10.0.1. Chicago, IL SPSS.Google Scholar
Strauss, S. Y. 1991. Indirect effects in community ecology: their definition, study, and importance. Trends Ecol. Evol. 6:206210.Google Scholar
Strauss, S. Y. and Agrawal, A. A. 1999. The ecology and evolution of plant tolerance to herbivory. Trends Ecol. Evol. 14:179185.Google Scholar
Thelen, G. C., Vivanco, J. M., Newingham, B., Good, W., Bais, H. P., Landres, P., Caesar, A., and Callaway, R. M. 2005. Insect herbivory stimulates allelopathic exudation by an invasive plant and the suppression of natives. Ecol. Lett. 8:209217.Google Scholar
Tremmel, D. C. and Bazzaz, F. A. 1993. How neighbor canopy architecture affects target plant performance. Ecology. 74:21142124.Google Scholar
Trumble, J. T., Kolodny-Hirsch, D. M., and Ting, I. P. 1993. Plant compensation for herbivory. Annu. Rev. Entomol. 38:93119.Google Scholar
Welter, S. C. 1991. Responses of tomato to simulated and real herbivory by tobacco hornworm (Lepidoptera: Sphingidae). Environ. Entomol. 20:15371541.Google Scholar
Wilcove, D. S., Rothstein, D., Dobow, J., Phillips, A., and Losos, E. 1998. Quantifying threats to imperiled species in the United States. Bioscience. 48:607615.Google Scholar
Wilkinson, L. 1990. SYSTAT: The system for statistics. Evanston, IL SYSTAT. 313.Google Scholar
Windle, P. N. and Franz, E. H. 1979. The effects of insect parasitism on plant competition: greenbugs and barley. Ecology. 60:521529.Google Scholar
Wirf, L. A. 2006. The effect of manual defoliation and Macaria pallidata (Geometridae) herbivory on Mimosa pigra: implications for biological control. Biol. Control. 37:346353.Google Scholar
Wooton, J. T. 1994. The nature and consequences of indirect effects in ecological communities. Annu. Rev. Ecol. Evol. S. 25:443466.Google Scholar