Recent dynamics of pine and oak forests in Mexico

Temperate forests worldwide are dominated by two families, Pinaceae and Fagaceae. In the last decades, temperate forests are experiencing rapid changes and, in some regions, a directional increase in Fagaceae abundance at the expense of Pinaceae has been detected. Here, we analyze the recent forest dynamics of Pinaceae and Fagaceae in Mexican forests to assess whether there is a directional change in the relative abundance of these two families and identify the environmental factors that are determining their recent growth dynamics. We take advantage of repeated surveys data from the Mexican National Forest and Soil Inventory, obtained in 2004–2007 and 2009–2014. Our results show that, at present, there is no overall directional trend in the changes of the relative abundance of Pinaceae and Fagaceae in the temperate forests of Mexico, which likely reflects a complex mixture of forest dynamics, locally dominated by different types of disturbance or successional dynamics. At the same time, however, we find evidence that the growth of Fagaceae species is responding more favorably than that of Pinaceae to currently rising temperatures in Mexico. Although these results need to be confirmed by longer-term studies, the resulting changes in composition could potentially have strong impacts on forest ecosystem function in the midterm.