Vegetation patch dynamics and tree diversity in a diverse conifer and oak forest in central Mexico

Abstract

Mexican conifer and oak forests are very diverse, and represent the vegetation type with the highest timber production in Mexico. Yet, there is little knowledge about the relationship of forest recovery and tree diversity in this type of vegetation. In this study, we analyzed the dynamics of vegetation patches over three time periods covering five decades, within an area in central Mexico dominated by conifer and oak forest. We identified vegetation patches, and evaluated their number and changes in patch size and vegetation cover. We also evaluated the composition and structure of the plant canopy in vegetation plots representing different canopy cover classes. Over the three periods studied, the number and total area of patches remained relatively constant, but an increase in canopy vegetation cover occurred in most vegetation patches. Patch canopies were dominated by the long-lived pioneer tree species Juniperus deppeana and the shrub Arctostaphylos pungens . We suggest that forest management in our study region should focus on facilitating the dominance of pines and oaks in sites that have recovered their canopy cover, and to identify the factors inhibiting succession in patches with less than 10 % vegetation cover.