New Phytologist (2016) 211, 1371-1381

Xinmin Lu, Evan Siemann, Minyan He, Hui Wei, Xu Shao and Jianqing Ding (2016)
Warming benefits a native species competing with an invasive congener in the presence of a biocontrol beetle
New Phytologist 211 (4), 1371-1381
Abstract: - Climate warming may affect biological invasions by altering competition between native and non-native species, but these effects may depend on biotic interactions.
- In field surveys at 33 sites in China along a latitudinal and temperature gradient from 21°N to 30.5°N and a 2-yr field experiment at 30.5°N, we tested the role of the biocontrol beetle Agasicles hygrophila in mediating warming effects on competition between the invasive plant Alternanthera philoxeroides and the native plant Alternanthera sessilis.
- In surveys, native populations were perennial below 25.8°N but only annual populations were found above 26.5°N where the invader dominated the community. Beetles were present throughout the gradient. Experimental warming (+ 1.8°C) increased native plant performance directly by shifting its lifecycle from annual to perennial, and indirectly by releasing the native from competition via disproportionate increases in herbivory on the invader. Consequently, warming shifted the plant community from invader-dominated to native-dominated but only in the presence of the beetle.
- Our results show that herbivores can play a critical role in determining warming effects on plant communities and species invasions. Understanding how biotic interactions shape responses of communities to climate change is crucial for predicting the risk of plant invasions.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jian Qing Ding, Evan Siemann

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Alternanthera philoxeroides (weed)		China (south)
Agasicles hygrophila (weed bioagent)	Alternanthera philoxeroides (weed)		China (south)