Vegetation Structure, Classification and Climatic Characteristics in Temperate-like Mountain Forests Dominated by Abies jaliscana in Western Mexico

Abstract

Aim
 of study:
 Examine patterns in woody species composition, vegetation structure,
 precipitation and temperature parameters over two fir forest elevation ranges
 and to discuss some biome-climate characteristics.
 
 Area
 of Study:
 Field sampling was conducted in 20 Abies
 forest sites over two elevation ranges (Laguna Juanacatlan and Cerro La Bufa)
 in western Jalisco, Mexico.
 
 Material
 and Methods: Using linear regressions, relationships between climate and
 fir forest structure were inferred. We examined vegetation structure
 complemented by cluster and indicator species analyses.
 
 Main
 results: A
 total of 2378 stems belonging to 67 species were recorded, species richness and
 Shannon index were not different between localities. Cluster analysis suggest
 three forest types: upper montane cloud forest (UMCF), mixed fir-UMCF and fir
 forest. Fir basal area and abundance showed differences between localities.
 Reverse J-shaped size distribution pattern was found, except in the Cerro La
 Bufa lower belt, where a J-shaped pattern indicates low recruitment and high
 number of canopy individuals. 
 
 Highlights: The
 lower temperatures and increase in winter rainfall along the elevational
 gradient, enable an auspicious habitat for western Mexican fir forests.