Climate change-driven competition between C4 weeds and crops: Ecological mechanisms, evolution and management strategies.

Global climate change is profoundly reshaping the competitive landscape between C4 weeds and crops. This review focuses on the unique CO2-concentrating mechanism of C4 weeds, elucidating the physiological and biochemical basis for their photosynthetic advantage under high-temperature and drought conditions, and systematically explaining how this advantage drives the restructuring of weed communities and the expansion of their geographical distribution. On this basis, it analyzes the regulatory pathways through which elevated CO2 concentration, temperature changes, and water stress affect the photosynthetic efficiency of C4 weeds, as well as the resulting shifts in aboveground and belowground resource competition patterns. In response to the limitations of current control strategies, a multidimensional management framework integrating agronomic, chemical, and biotechnological approaches is proposed. Finally, key directions for future research are identified, including the molecular dissection of the C4 photosynthetic regulatory network, the development of predictive models for climate-weed-crop interactions, and the development of targeted control technologies, thereby providing a forward-looking framework for addressing climate-driven weed risks.