Heat wave event facilitates defensive responses in invasive C3 plant
under elevated CO2 concentration to the detriment of insect herbivores
To predict and mitigate the effects of climate change on communities and
ecosystems, the joint effects ofextreme climatic events on species
interactions need to be understood.Using the common ragweed (Ambrosia
artemisiifolia L.)—leaf beetle (Ophraella communa) system, we
investigated the effects of heat wave and elevated CO2 on common ragweed
growth, secondary metabolism, and the consequent impacts on the beetle.
The results showed that elevated CO2 and heat wave facilitated A.
Artemisiifolia growth; further, A. artemisiifolia accumulated large
amounts of defensive secondary metabolites. Being fed on A.
artemisiifolia grown under elevated CO2 and heat wave conditions
resulted in the poor performance of O. communa (high mortality, long
development period, low reproduction). Overall, under elevated CO2, heat
wave strengthened the defensive ability of A. artemisiifolia to
herbivores. Super adaptability to climatic changes may aggravate
invasive plant distribution, posing a challenge to the control of
invasive plants in the future.