Institute of Botany
Sect. Plant Ecology
| Title | Gypsy moth feeding in the canopy of a CO₂-enriched mature forest |
| Author/s | Hättenschwiler S, Schafellner C |
| Year | 2004 |
| Journal | Global Change Biology 10:1899-1908 |
| Abstract | Rising atmospheric carbon dioxide (CO₂) concentration is expected to change plant tissue quality with important implications for plant-insect interactions. Taking advantage of canopy access by a crane and long-term CO₂ enrichment (530 µmol mol⁻¹) of a natural old-growth forest (web-free air carbon dioxide enrichment), we studied the responses of a generalist insect herbivore feeding in the canopy of tall trees. We found that relative growth rates (RGR) of gypsy moth (Lymantria dispar) were reduced by 30% in larvae fed on high CO₂-exposed Quercus petraea, but increased by 29% when fed on high CO₂-grown Carpinus betulus compared with control trees at ambient CO₂ (370 µmol mol⁻¹). In Fagus sylvatica, there was a nonsignificant trend for reduced RGR under elevated CO₂. Tree species-specific changes in starch to nitrogen ratio, water, and the concentrations of proteins, condensed and hydrolyzable tannins in response to elevated CO₂ were identified to correlate with altered RGR of gypsy moth larvae. Our data suggest that rising atmospheric CO₂ will have strong species-specific effects on leaf chemical composition of canopy trees in natural forests leading to contrasting responses of herbivores such as those reported here. A future change in host tree preference seems likely with far-ranging consequences for forest community dynamics. |
| Keywords | Elevated CO₂ · Global change · Herbivory · Leaf chemistry · Vaccinium sp. |
| Contact | Stephan Hättenschwiler: email | webpage |
| Research project | The Swiss Canopy Crane Project (SCC) |