Land used for pasture is at risk of becoming a breeding ground for weeds that invade natural areas.

Roughly 30% of land worldwide is devoted to growing forage plants for livestock, and as demand for meat rises, farmers are moving towards more-productive and hardier plants. Don Driscoll at the Australian National University in Canberra and his colleagues looked at data on pasture species promoted by 17 agribusinesses and government agriculture agencies on six continents, and found that 91% of the plants were classified as potentially invasive weeds — often in the same country in which they were developed and marketed. Only one of the 17 institutions had a formal process for identifying possible weeds.

The researchers suggest solutions for this problem, including making the organization that promotes the pasture species financially liable for controlling it if it becomes invasive.

Proc. Natl Acad. Sci. USA http://doi.org/wxq (2014)

For a video on the research, see go.nature.com/gqxoed