[unsrsly]

Fire burning through grass and vineyards has been a feature of the latest fire season in northern CA. Given how dry and hot the climate is, only dirt is a sure thing. However with high enough winds, embers can carry long distances and cross fire breaks. For example in 2017, the Tubbs fire crossed highway 101. But I still agree that living close to trees is worse.

[dredmorbius]

Grass burns, yes, but quickly and generally not in conflagrations. Trees are often (though not always, and increasingly less so) largely untouched by grass fire. Back-burning is highly effective on grassfire.

Scrub burns ferociously, far more violently than one might expect, thanks to the volatile oils. For much of Southern California, this is a poorly-manageable threat.

An entrenched crown fire is a true fury, not to be trifled with. The main fire can burn in a location for hours (rather than minutes), and individual trees or roots for days, even months.

The heat from even a modest forest fire is ferocious. I found myself a 1/2--1/4 mile or so from a relatively small burn (an acre or so), and could feel the radiant heat from inside a car.

A hillside on fire, or a fire-front overtaking a position, is like a blast furnace, with temps over 1,500°F. Plus choking, blinding smoke, poisonous fumes, low oxygen, and flying and falling flaming debris.

A 1km deforested buffer might help, along with building codes.