(Davis, CA) — A study out of UC Davis reveals that smoke from large wildfires in 2020 and 2021 harmed the nut harvest in California’s Central Valley, potentially indicating broader environmental issues and issues with production.

Researchers examined data from over 400 farms to see if wildfire smoke affected crops like pistachios, walnuts, and almonds. They found that smoke and ash blocked about 20-percent of sunlight needed by the trees, while harmful ozone from the fires made photosynthesis harder, significantly impacting nut production.

Experts suggest that smoke could impact not only nut trees but also forests and crops like grapevines, which bear fruit during fire season.