Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1890/06-0647
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Title (Primary) Antagonistic interactions between plant competition and insect herbivory
Author Sch├Ądler, M.; Brandl, R.; Haase, J.
Journal Ecology
Year 2007
Department BZF
Volume 88
Issue 6
Page From 1490
Page To 1498
Language englisch
Keywords antagonistic interactions; aphids; insect herbivory; Plantago lanceolata; plant competition; Poa annua; Rhopalosiphum padi; Trifolium repens
Abstract Interspecific competition between plants and herbivory by specialized insects can have synergistic effects on the growth and performance of the attacked host plant. We tested the hypothesis that competition between plants may also negatively affect the performance of herbivores as well as their top-down effect on the host plant. In such a case, the combined effects of competition and herbivory may be less than expected from a simple multiplicative response. In other words, competition and herbivory may interact antagonistically. In a greenhouse experiment, Poa annua was grown in the presence or absence of a competitor (either Plantago lanceolata or Trifolium repens), as well as with or without a Poa-specialist aphid herbivore. Both competition and herbivory negatively affected Poa growth. Competition also reduced aphid density on Poa. This effect could in part be explained by changes in the biomass and the nitrogen content of Poa shoots. In treatments with competitors, reduced aphid densities alleviated the negative effect of herbivory on above- and belowground Poa biomass. Hence, we were able to demonstrate an antagonistic interaction between plant-plant interspecific competition and herbivory. However, response indices suggested that antagonistic interactions between competition and herbivory were contingent on the identity of the competitor. We found the antagonistic effect only in treatments with T. repens as the competitor. We conclude that both competitor identity and the herbivore's ability to respond with changes in its density or activity to plant competition affect the magnitude and direction (synergistic vs. antagonistic) of the interaction between competition and herbivory on plant growth.
Persistent UFZ Identifier
Sch├Ądler, M., Brandl, R., Haase, J. (2007):
Antagonistic interactions between plant competition and insect herbivory
Ecology 88 (6), 1490 - 1498