The Altitudinal Belts of the Vegetation in the Central Mexican Highlands and Their Climatic Conditions

Abstract

The vegetation belts at high altitudes in the Central Mexican Highlands are not exclusively tropical in character. This is especially true of the tierra fria. Even the main part of the tierra templada contains a considerable variety of holarctic floristic elements. The timberline in the Mexican Highlands (approximately 4,000 m) is formed by one species of pine (Pinus hartwegii), and the slopes to the Caribbean side are characterized down to an altitude of 1,200 m by a number of boreal species among them many oaks and a Mexican beech species (Fagus mexicana). The climatic conditions suggest that this region should be considered rim-tropical. Using the three-dimensional weather system classifica