In California, we have Tumbleweed, and it’s actually really useful for stabilizing/fertilizing loose, disturbed soils and making shelter for native grasses and plants to start growing near. They also love to fuck with cars by jumping out in front of them at every opportunity.
Increases fire hazard (though may be a hazard primarily to human landscapes).
In other words, it doesn’t meaningfully contribute to the overall ecological fire hazard, you’re mostly talking highway veg fires and stuff, which happen with or without tumbleweeds.
JAPANESE KNOTWEED (mander.xyz)