Characterization and phytoclimatic potentialities of Quercus petraea (Matt.) Liebl. and Quercus robur L. forests in Spain

Abstract

This paper presents some contributions to the phytoclimatic characterization of stands of Quercus petraea (Matt.) Liebl. and Quercus robur L. in España. For the phytoclimatic characterization, 577 sampling points from the 2nd National Forest Inventory of actual vegetation in which Quercus petraea was the principle especies in the forest were considered and 1,780 sampling points for Quercus robur. The phytoclimatic diagnosis followed the phytoclimatic models of Allué-Andrade. Phytoclimatic territorial models were constructed in digital format on the basis of preliminary territorial factorial estimations, wich were used to determine climatic factors and phytoclimatic terns. The potential phytoclimatic area and the factorial ambits for the existence of oak stands was performed in five phases of increasing strictness, based on factorial comparison (convex hull), phytoclimatic terns comparison, phytoclimatic suitability and evaluation of competitor forest species. Quercus petraea stands are found in the phytoclimatic subtypes VI(IV)2, VI(IV)4, VI(V), VI(VII), VI and VIII(VI). Subtype VI is both the most prevalent of the species and the one with the highest index of phytoclimatic suitability. The highest phytoclimatic suitability is found in the phytoclimatic terns with genuine subtype in VI and first analogous subtype in VI(V). In the strictest phase this calculation determined potential areas of high phytoclimatic viability for Quercus petraea totalling 1,969,000 ha in the north of Spain. Quercus robur stands are found in the phytoclimatic subtypes VI(IV)2, VI(IV)3, VI(IV)4, VI(V) and VI. Subtype VI(V) is both the most prevalent of the species and the one with the highest index of phytoclimatic suitability. In the strictest phase this calculation determined potential areas of high phytoclimatic viability for Quercus robur totalling 2,989,000 ha.