The different occurrence conditions of Quercus robur L. and Quercus petraea (Mattuschka) Liebl. on current habitat in Galicia, NW Iberian Peninsula

Abstract

The aim of this study was to characterize the current habitats of Galician Atlantic deciduous oaks, Quercus robur L. and Quercus petraea (Mattuschka) Liebl. Description of site variability is required to aid management as regards future actions for preserving them. Ninety-two rectangular sampling plots of variable dimensions were installed to include at least 50 trees of diameter larger than the minimum inventory size (5 cm). Physiographical, dendrometric and profile data were obtained and managed with climatic data to calculate some habitat-related parameters. The results indicate the differences in site conditions for both species; the Q. petraea habitat was characterized by higher precipitation, more variable soil properties and a higher degree of humidification than in Q. robur. The most important parameters for classifying the Q. robur habitat were altitude, slope, soil depth, distance to sea, total precipitation, mean temperature, mean maximum and mean minimum temperature. Regard to Q. petraea, they were altitude, pH, soil K, organic matter and Ca. The habitat model provided a good fit to the Q. robur although there was a large error associated with the final prediction, indicated by the linear trend of the residuals. The model performed better for Q. petraea because the error was smaller.