Exotic invasive plant accumulates native soil pathogens which inhibit native plants
Article first published online: 31 OCT 2007
Journal of Ecology
Volume 96, Issue 1, pages 58–67, January 2008
How to Cite
Mangla, S., Inderjit and Callaway, R. M. (2008), Exotic invasive plant accumulates native soil pathogens which inhibit native plants. Journal of Ecology, 96: 58–67. doi: 10.1111/j.1365-2745.2007.01312.x
- Issue published online: 31 OCT 2007
- Article first published online: 31 OCT 2007
- Received 16 February 2007; accepted 3 September 2007 ; Handling editor: Marcel van der Heijden
- Chromolaena odorata;
- fungal pathogen;
- indirect interactions;
- soil biota;
- soil pathogen;
- root leachate
- 1We investigated the role of a native generalist soil pathogen through which a non-native invasive plant species may suppress naturalized/native plant species.
- 2We found that rhizosphere soils of Chromolaena odorata, one of the world's most destructive tropical invasive weeds, accumulate high concentrations of the generalist soil borne fungi, Fusarium (tentatively identified as F. semitectum), thus creating a negative feedback for native plant species.
- 3Soils collected beneath Chromolaena in the Western Ghats of India inhibited naturalized/native species and contained over 25 times more spores of the pathogenic fungi Fusarium semitectum than soils collected at the same locations beneath neighbouring native species that were at least 20 m from any Chromolaena plant. Sterilization of these soils eliminated their inhibitory effect. Chromolaena root leachate experimentally added to uninvaded soils increased Fusarium spore density by over an order of magnitude, and increased the inhibitory effect of the soils.
- 4The positive effect of Chromolaena root leachates on Fusarium spores was attenuated by activated carbon, suggesting a biochemical basis for how the invader stimulated the pathogen.
- 5Synthesis. Invasive plants have been shown to escape inhibitory soil biota in their native range and to inhibit soil biota in their invaded range, but our results indicate that the impacts of Chromolaena are due to the exacerbation of biotic interactions among native plants and native soil biota, which is to our knowledge a new invasive pathway.