The Premature Mortality of Sabinos or Montezuma Bald Cypress ( Taxodium mucronatum Ten.) in the State of Durango, Mexico

The juniper ( Taxodium mucronatum Ten. of the Cupressaceae family) is a long-lived species that forms gallery forests. Dozens of dead junipers > 100 years old have been identified in the San Pedro Mezquital watershed in Durango, Mexico. This work determines the causes of death of these specimens. The work was carried out in the field and in the laboratory, where in the former the surface of the damaged trees was identified, together with the changes observed in the watercourses. In the latter, sabino seedlings were transported to the work center and exposed for 7 days in containers with gravel to five types of wastewater generated in the region. With the above, the conditions experienced by the adult trees in the field were studied, as well as the sensitivity of the young specimens to the types of water quality, and the differences were validated with ANOVA tests. Five sites with dead junipers were found, ranging in size from 0.5 to 4 ha, with ages between 200 and 400 years. It was found that during the dry season, water is diverted to irrigated areas, leaving some areas without water for several months. The shoots survived in most of the water qualities, except the one with high salinity (3.34 mS/cm). It is concluded that the lack of water in the rivers had a stronger influence than the water quality and is the probable cause of the death of the sabino.