Invasive plants often flourish in areas that have been disturbed by fire, outcompeting native plants and disrupting ecosystems. A new study led by researchers at the University of California, Davis, has uncovered how invasive plants gain this head start after fire.

The study, published in the journal "Ecology Letters," found that invasive plants are able to germinate and grow more quickly after fire because they have higher levels of a hormone called abscisic acid (ABA). ABA helps plants to tolerate drought and other stresses, and it also promotes seed germination.

"We found that invasive plants have higher levels of ABA in their seeds than native plants," said lead author Dr. Erica Spotswood, a postdoctoral researcher at UC Davis. "This allows them to germinate and grow more quickly after fire, when conditions are harsh and water is scarce."

The researchers also found that invasive plants are able to produce more ABA in response to fire cues, such as smoke and heat. This means that they can quickly ramp up their ABA production after a fire, giving them a further advantage over native plants.

"Our findings suggest that invasive plants have evolved to take advantage of the conditions that occur after fire," said senior author Dr. David Ackerly, a professor of ecology and evolutionary biology at UC Davis. "This gives them a head start in the race to colonize burned areas, and it can help them to become dominant in these ecosystems."

The study has implications for managing invasive plants and restoring ecosystems after fire. By understanding how invasive plants gain a head start after fire, land managers can develop more effective strategies for controlling them and promoting the recovery of native plant communities.

"Our work provides new insights into the mechanisms that allow invasive plants to succeed after fire," said Spotswood. "This information can be used to develop more targeted and effective management strategies to protect native plant communities and restore fire-affected ecosystems."