Environmental and spatial processes shaping Quercus‐dominated forest communities in the Neotropics

Abstract

Quercus‐dominated forests in the Neotropics compose one of the broadest distributed ecosystems of mountainous zones whose species distribution has been explained by climate change adaptation over an abrupt physiography. This study aims to comprehend the contribution of environmental and spatial processes influential in species composition of Quercus‐dominated forests. A database of 86 plots, randomly located in a highly diverse spot of the Mexican Neotropics, was examined; it involved vegetation, environment, and spatial data. Local spatial variables were derived from distance‐based Moran's eigenvector maps, while regional spatial variables were obtained from geographical coordinates (latitude/longitude). Redundancy analysis and variance partitioning were run to reveal the relative importance of environmental and spatial processes explaining plant species composition of Quercus‐dominated forests and ascertain the environmental variables controlling the species composition at the different spatial scales (local and regional). Results showed that both local and regional spatial variables significantly control species composition in Quercus‐dominated forests, with the regional scale accounting for a higher explained variance than the local scale. At the regional scale, elevation, aspect, litter, maturity, and Mg were significant in explaining species community composition; elevation variance was twofold higher than variance for aspect and litter. At the local scale, elevation accounted for the highest variation followed by maturity, P, N, and Mg. The analysis also tested the variation of species community composition over environmental gradients mainly determined by elevation. This study indicated the importance of elevation at both local and regional spatial scales as an important driver in Quercus‐dominated forests distribution, probably related to Quercus species adaptation to temperature and precipitation. Finally, evidence from this research emphasizes the significance and necessity of a multiscale analysis to discern the spatial structured environment responsible for the high species diversity and broad distribution of forests dominated by Quercus genus in the Neotropics.