Taxus globosa Schltdl.

Taxaceae

Distribution

Taxus globosa is sporadically distributed from northern Mexico (Tamaulipas and Nuevo León) to Honduras and El Salvador in Central America. In Mexico it is known from the states of Hidalgo, Querétaro, Puebla, Oaxaca, Veracruz, Chiapas, Nuevo León, San Luis Potosí and Tamaulipas. In Guatemala, it is restricted to the Sierra de Cuchumatanes and central Guatemala (Departments Baja Verapaz, El Progreso, Zacapa and Huehuetenango. In Honduras it is recorded from the Departments of Ocotepeque, Lempira and Santa Barbara. In El Salvador it is only known from Cerro el Pittla, the highest mountain in the country. Its total extent of occurrence is well in excess of 20,000 km² and it is known from more than 10 locations. Due to its limited habitat and sporadic distribution, the area of occupancy is likely to be less than 2,000 km². It is found at altitudes ranging from 1,000 to 3,300 m a.s.l.

Throughout its range, populations are usually small and disjunct. In El Salvador there are as few as six trees in a single location (F. Tobar pers. comm. March 2012).

Habitat and Ecology

Taxus globosa is almost always found in the low and middle tree layers of montane forest, oak forest, and pine-oak forest and is considered as a indicator species for cloud forest. It shows a strong preference for moist and shaded ravines.

Human Uses

Locally used for fence posts. As with most other Taxus species, T. globosa is a potential source of anti-cancer drugs. However, its subpopulations are likely to be too small and scattered to make harvesting of wild plants commercially viable. Plantation cultivation would be the only viable and sustainable option.

Conservation Status

Global Conservation Status and Rationale: Endangered A2c

The extent of occurrence is well in excess of 20,000 km². The area of occupancy (AOO) is unknown but is likely to be less than 2,000 km²; while it is known from many localities it is never common and does not form large stands. Past and current exploitation and deforestation of montane cloud forests is likely to have led to a reduction in the total population size; this is likely to continue. Recent research on the Mexican subpopulations that represent the major proportion of the global population, indicate that as much as 80% of its potential habitat has been lost since 1970 (Contreras-Medina et al. 2010). Montane cloud forests have also been heavily exploited in other parts of its range. An overall reduction of at least 50% within the last three generations is probably a conservative estimate. Consequently an assessment of Endangered under the A2 criterion is warranted.

National Conservation Status

In Guatemala it has been assessed as nationally VU under the B2 criterion (Vivero 2006). In Mexico it has been assessed as Endangered under the A criterion (Espinosa et al. 2011).

Conservation Actions

Although it is known from several protected areas that span most of its range, the vast majority of known localities are outside of such areas (Contreras-Medina et al. 2011). It is necessary to develop management plans to recover and conserve this species both within and outside protected areas.