Location: Rangeland Resources & Systems ResearchTitle: Understanding the combined impacts of weeds and climate change on crops
|VILA, MONTSERRAT - Doñana Biological Station|
|BEAURY, EVELYN - University Of Massachusetts|
|BRADLEY, BETHANY - University Of Massachusetts|
|EARLY, REGAN - University Of Exeter|
|LAGINHAS, BRITTANY - University Of Massachusetts|
|TRILLO, ALEJANDRO - Doñana Biological Station|
|DUKES, JEFFREY - Purdue University|
|SORTE, CASCADE - University Of California|
|IBANEZ, INES - University Of Michigan|
Submitted to: Environmental Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2021
Publication Date: 3/1/2021
Citation: Vila, M., Beaury, E., Blumenthal, D.M., Bradley, B.A., Early, R., Laginhas, B.E., Trillo, A., Dukes, J.S., Sorte, C.J., Ibanez, I. 2021. Understanding the combined impacts of weeds and climate change on crops. Environmental Research. 16(3). Article e034043. https://doi.org/10.1088/1748-9326/abe14b.
Interpretive Summary: Weeds are a major constraint to crop production, being weed control the costliest element of crop protection worldwide. As climate changes, future food production may be further impacted by elevated CO2, warmer temperatures, and drought. Even though it is increasingly clear that climate change and competition from weeds could interact, existing assessments of potential changes in crop yield do not account for the combined effects of these threats. Our global meta-analysis found that the impacts of climate change and weeds are predictable such that the magnitude and impact of weeds on crops is more variable, but no different under current or future climate.
Technical Abstract: Crops worldwide are simultaneously affected by weeds, which reduce yield, and by climate change, which can negatively or positively affect both crop and weed species. While the individual effects of climate change and weeds on crop yield has been assessed, it is unknown whether their combined effects will lead to better or worse outcomes for crops. To understand the simultaneous impacts of weeds and climate change on future food production, we conducted a meta-analysis of 164 experimental studies measuring the individual and combined effects of weeds and climate change (i.e., elevated CO2, drought or warming) on 23 crop species. The combined effect of weeds and climate change tended to be additive. The magnitude of the impact of weeds on crops was more variable with climate change but not different than under current climate. The negative effect of weeds counteracted the positive effects of CO2 and warming on crop yield, but added to the negative effect of drought. The impact of weeds with climate change was dependent on the photosynthetic pathway of the weed/crop pair and on the climate treatment under consideration. Native and non-native weeds had similar negative effects on yield, with or without climate change. Weed impact with climate change was also independent of whether the crop was infested with a single or multiple weed species. The impact of weeds under climate change was highly variable across crop species. However, since weed impacts remain negative under climate change, increased weed management will be necessary to ensure adequate food production.