EARLY GROWTH IN SEEDLINGS FROM TWELVE PROVENANCES OF Pinus hartwegii Lindl. IN NURSERY CONDITIONS

Abstract

Pinus hartwegii is widely distributed in Mexico and even reach the Republic of El Salvador in Central America. The populations of this species in the central region of Mexico are located in the highest zones of the mountain ranges, commonly designated as natural protected areas, important generators of ecosystemic services to the society. Studies related to variation among provenances of P. hartwegii had been developed, especially in cones and leaves morphology, as well as seed characteristics. Variation in the initial growth among seedlings of different provenances growing in nursery conditions has never been determined. This response was evaluated in 12 provenances from the mountain range named Eje Neovolcánico that cross Mexico from east to west and an experimental design of random blocks with 56 repetitions from each provenance was used. The parameters measured in the seedlings were basal diameter and height, in addition to the growing rates of these variables in a period of 10 months. Seedlings from the population of Cofre de Perote showed the most extreme values among provenances in these variables and were significantly different. However, the groups defined after the statistical analysis do not allow the identification of any geographic pattern related to a latitudinal or longitudinal gradient, and the variation found among the provenances of this species could be related to local conditions in which the populations developed and drive the selection process in those individuals.