Vanishing of the mighty tunales of central Mexico: A 5-century history of landscape change

Before the 16th century, tunales, majestic forests of arborescent nopales (Opuntia spp.), were a signature of the southern part of the Mexican Plateau. They were crucial for nonagricultural humans and wildlife and created the cultural identity of the region. Notwithstanding this, they have been drastically reduced and disparaged into modern times. We aimed at reconstructing the history of the disappearance of these tunales and elaborate on the ecological and cultural impacts of such disappearance. The historicizing of such processes is critical to establish restoration objectives concordant with ecological timeframes, rather than by human memory. To fulfill our objective, we reviewed published formal and gray literature (i.e., publications with limited circulation, theses), and unpublished archival documents, complementing this information and interpreting it with our own >25-year research experience each in the region. Despite some differing opinions, most 15th-century tunales were natural. Agricultural development in the 17th–19th centuries affected mostly tunales in humid bottomlands. Those on hills and slopes apparently escaped this initial transformation. After the Mexican Revolution (1910–1921), the plowing of hills and slopes destroyed many remaining tunales. Some persisted into the 21th century, but their felling has continued. Our study exemplifies how natural iconic communities once widely distributed can vanish almost inadvertently. With the loss of the tunales, the region has lost a unique, iconic plant community which harbored several plant species endemic to Mexico. Arborescent nopales are hardy, but to avoid the complete disappearance of the tunales, their ecological and biocultural importance and significance must be revaluated, and strong lobbying efforts and management actions developed.