Structural analysis of an agroforestry area in a portion of the xeric shrubland of northeast of Mexico Autores: Alanis Rodriguez, Eduardo, Valdecantos Dema, Alejandro, Canizales Velázquez, Pamela Anabel, Collantes Chavez-Acosta, Alejandro, Rubio Camacho, Ernesto, Mora Olivo, Arturo