Specific bottom-up effects of arbuscular mycorrhizal fungi across a plant-herbivore-parasitoid system

• Published in: Oecologia Vol. 160; no. 2; pp. 267 - 277
• Main Authors: Hempel, Stefan, Stein, Claudia, Unsicker, Sybille B, Renker, Carsten, Auge, Harald, Weisser, Wolfgang W, Buscot, François
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.05.2009; Springer; Springer-Verlag; Springer Nature B.V
• Subjects: Analysis of Variance; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Aphididae; Aphidius rhopalosiphi; Aphids - parasitology; Aphids - physiology; Autoecology; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Ecology; Foliage; Food Chain; Fundamental and applied biological sciences. Psychology; General aspects; Germany; Glomus intraradices; Herbivores; Hydrology/Water Resources; Hymenoptera; Life Sciences; Mosses; Mycorrhizae - physiology; Mycorrhizal fungi; Nitrogen - analysis; Nutritional status; Parasitism; Parasitoids; Phleum - chemistry; Phleum - growth & development; Phleum - microbiology; Phleum pratense; Phosphorus - analysis; Plant biomass; Plant interaction; Plant roots; Plant Sciences; Plant- Animal Interactions - Original Paper; Plants; Plants and fungi; Population Dynamics; Population growth; Population growth rate; Rhopalosiphum padi; Symbiosis; Trophic levels; Trophic relationships; Wasps - physiology; Germany; Multitrophic interactions; Insect herbivory; Parasitoid performance; Aphidius rhopalosiphi; Aphidoidea; Herbivorous; Insecta; Rhopalosiphum padi; Symbiont; Fungi; Bottom up control; Endomycorrhiza; Parasitoid; Homoptera; Animal plant relation; Arthropoda; Mycorrhiza; Aphididae; Invertebrata; Performance
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-009-1294-0

The majority of plants are involved in symbioses with arbuscular mycorrhizal fungi (AMF), and these associations are known to have a strong influence on the performance of both plants and insect herbivores. Little is known about the impact of AMF on complex trophic chains, although such effects are conceivable. In a greenhouse study we examined the effects of two AMF species, Glomus intraradices and G. mosseae on trophic interactions between the grass Phleum pratense, the aphid Rhopalosiphum padi, and the parasitic wasp Aphidius rhopalosiphi. Inoculation with AMF in our study system generally enhanced plant biomass (+5.2%) and decreased aphid population growth (-47%), but there were no fungal species-specific effects. When plants were infested with G. intraradices, the rate of parasitism in aphids increased by 140% relative to the G. mosseae and control treatment. When plants were associated with AMF, the developmental time of the parasitoids decreased by 4.3% and weight at eclosion increased by 23.8%. There were no clear effects of AMF on the concentration of nitrogen and phosphorus in plant foliage. Our study demonstrates that the effects of AMF go beyond a simple amelioration of the plants' nutritional status and involve rather more complex species-specific cascading effects of AMF in the food chain that have a strong impact not only on the performance of plants but also on higher trophic levels, such as herbivores and parasitoids.