This campesino is selling leña (firewood) and abono (compost) door-to-door.
The leña is fallen, salvaged mesquite. Far better to use this stuff than firewood from cutting live plants. Like the hotels and restaurants do. New wood looks better in the fireplace, but the cost is very high: deforestation and erosion of Central Mexico.
Better still would be not to burn firewood at all. But for many of us, fireplaces provide our only source of heat during the cold nights of December and January. Stone houses become uncomfortably chilly without at least a little supplemental heat.
Our house uses unvented gas logs; nice ones supplied by Chiapas's dad, Clint. This fireplace is in Jean's quilting studio.
Run it for just a few minutes, and the place gets toasty warm.
The abono isn't really compost. It's vegetable matter from the forest floor, raked up and bagged. It works pretty well for improving the garden. When the campesino sells you a bag or two, he asks for his bags back, so you have to have something to put it in. He operates a low-margin business.
In US national and state parks, we have policies that prohibit the collecting of humus and fallen firewood. Dead matter left to decompose returns nutrients to the trees. Removing it diminishes the heath of the forest.
I often wonder: Are campesinos delivering wood and compost by burro simply doing their business in a traditional and cost-effective way? Or are they pandering to gringos charmed by the romance of Old Mexico?
I don't really want to know.