Four Methods for Partial Overstory Removal in Tropical Forests in Mexico

A study was carried out to identify an efficient and low-cost method to kill seven tropical tree species as a means of achieving overstory removal. Four methods were tested: two chemical injection techniques (Banvel CST Herbicide and Esteron 47 M) and two physical treatments (girdling bands 20 cm and 40 cm wide). Overall, there was a substantial difference among the four treatments. Esteron 47 M was the most effective treatment, with 68% mortality. Banvel and girding 20-cm bands and 40-cm bands resulted in 57, 57 and 53% mortality, respectively. Mortality varied considerably among the species. Although girding is more time-consuming than using chemicals, it is recommended, when possible, because, of low application cost and avoidance of chemical pollution and danger to workers. Safety equipment is not readily available in tropical areas. Even if it were, it is not comfortable to use under tropical conditions. People living in the tropics are usually accustomed to the use of machete and hatchet, and accidents very seldom occur.