The basic sample was based on lines or transects of 200 m each, for a total of 30 lines, on each of which six parcels were disposed, separated by a distance of 40 m or transects each, adding up to 180 parcels: 13 in an oak forest, 10 in a subtropical shrubland, and seven in induced grasslands.
El muestreo base se hizo sobre líneas o transectos de 200 m cada uno, para un total de 30 líneas, y en cada una se colocaron seis parcelas, separadas 40 m una de otra para sumar 180 parcelas: 13 en bosque de encino, 10 en matorral subtropical y siete en pastizal inducido.