Another problem is the slash-and-burn agriculture practiced by the
Lacandon for centuries. Rain forest topsoil is very thin; new immigrants as
well as the Lacandon slash the rain forest, burn it, farm it for a few years,
deplete the soil, move on to another plot, and then begin the process again.
The Lacandon rain forest is the last vestige of a great rain forest that once
covered most of southern Mexico