Effects of environmental stress cascade up through four trophic levels in a salt marsh study system
Article first published online: 13 SEP 2010
© 2010 The Authors. Ecological Entomology © 2010 The Royal Entomological Society
Volume 35, Issue 6, pages 721–726, December 2010
How to Cite
MOON, D. C. and MOON, J. C. (2010), Effects of environmental stress cascade up through four trophic levels in a salt marsh study system. Ecological Entomology, 35: 721–726. doi: 10.1111/j.1365-2311.2010.01232.x
- Issue published online: 11 NOV 2010
- Article first published online: 13 SEP 2010
- Accepted 29 July 2010First published online 13 September 2010
- host-plant quality;
- trophic cascade
1. Although in recent years there have been a number of studies demonstrating trophic cascades in terrestrial systems, it is still unclear what environmental conditions enable or enhance such cascades, especially among four trophic levels.
2. In this study, the influence of environmental stress (increased soil pore water salinity) on a four trophic level study system in a Florida salt marsh was examined by experimentally increasing soil pore water salinity. Effects of increased salinity on the quality of the host plant, Batis maritima, were assessed, as were resulting effects on the lepidopteran herbivore Ascia monuste, and the primary parasitoids and hyperparasitoids of its caterpillars.
3. Increased salinity altered host-plant quality, which subsequently affected the consumer species. These effects of altered plant quality cascaded up through the herbivore and primary parasitoid to the hyperparasitoid Hypopteromalus inimicus, influencing its density, sex ratio, body size, and initial egg load.
4. These results demonstrate how heterogeneity in environmental stress can result in effects that cascade up through four trophic levels. We suggest that such strong effects at higher trophic levels may be more likely in systems in which relationships are more specific and intimate such as those among hosts, parasitoids, and hyperparasitoids.