Elevated temperature reduces wheat grain yield by increasing pests and decreasing soil mutualists.

BACKGROUND: Climate warming is known to affect species' phenology, abundance, and their interactions with other species. Understanding how cultivated plants, their associated community members (including pest insects, natural enemies, soil microbes), and their interactions respond to warming to influence crop yields is critical to current and future food security. We conducted a two-year field study on the effects of elevated temperature on winter wheat growth and grain quality, insect pests, natural enemies, ground arthropods, weeds, and arbuscular mycorrhizal fungi (AMF).

RESULTS: Elevated temperature shortened the period of wheat growth, decreased grain yield, and reduced grain quality by increasing fiber and decreasing wet gluten, protein, total soluble sugars, and starch. Elevated temperature also increased aphid abundance while decreasing AMF colonization rates. Structural equation modeling indicated that the direct negative effect of warming on wheat yield was augmented by indirect negative effects via increased aphid and weed abundances along with decreased AMF colonization.

CONCLUSION: Climate change can potentially affect crop production and quality both directly and indirectly by modifying interactions with aboveground and belowground organisms. Future studies on the effects of climate change on crops should consider the responses of aboveground and belowground biotic community members and their interactions with crop plants. © 2018 Society of Chemical Industry.