The northern variety of Pinus greggii is restricted to a few areas of northeast Mexico. Continued deforestation may lead to this taxon being listed as threatened in the near future.
Distribution
Endemic to northeast Mexico: Coahuila, Nuevo Leon, and San Luis Potosi. The extent of occurrence (EOO) estimated on the basis of recorded herbarium specimens is 37,912 km². The area of occupancy is estimated to be 320 km2. There are four locations and the subpopulations are severely fragmented.
The size of subpopulations of this variety is generally smaller than of the southern variety australis with the majority covering less than 1,000 ha.
Habitat and Ecology
This northern variety is mainly found on alkaline soils (pH 7-8) derived from limestone. It is most commonly found scattered in mixed pine-oak forest.
Human Uses
Not specifically targeted for timber, but cut with other trees for general use. Rare in cultivation.
Conservation Status
Global Status
Near Threatened
Global Rationale
Unlike the southern variety, this northern variety occurs in areas which are less intensively affected by land clearance for agriculture. Some decline may occur, but it is possibly balanced by regeneration elsewhere as this pine also establishes in secondary forest. Its area of occupancy (AOO) is very likely within the threshold for an Endangered listing, and the population is certainly fragmented, but it does not meet the continuing decline criterion under B which is needed to be listed as threatened. It is therefore listed as Near Threatened.
Conservation Actions
No collections were recorded from protected areas. These should be established to include this taxon.
References and further reading
Donahue, K. and J. Lopez Upton. 1999. A new variety of Pinus gregii. Sida 18(4): 1083-1093.
Farjon, A. and Styles, B. 1997. Pinus (Pinaceae). Flora Neotropica. Monograph 75. The New York Botanical Garden, New York
Ramírez-Herrera, C., Vargas-Hernández, J.J. and López-Upton, J. 2005. Distribución y conservación de las poblaciones naturales de Pinus greggii. Acta Bot. Mex. 72: 1-16