A study was made of the genus Quercus in territories in the centre-south of the Iberian Peninsula and southern Italy. Samples were taken from various trees in homogeneous populations selected at each cardinal point: 110 samples were obtained for Spain, 34 for Portugal and 53 for Italy, with a total of 48 sampling points. Sampling was done in areas where there was complete certainty of the existence of a particular taxon, and even of the type, as well as in places where there was some doubt as to the presence of a taxon. In view of the controversy with regard to some species/subspecies of the genus Quercus in the mentioned territories, we used fractal analysis to discriminate the species, a technique that has been little used to the present in Botany, although it is widespread in Medicine. To calculate the fractal dimension we opted for the “box-counting” method integrated in the software Harfa v.5.4.38, as it allows the evaluation of the fractal dimension of structures which are not totally self-similar. Once the fractal values have been obtained, the differences are analysed in order to obtain the minimum value for species for which there is no discrepancy among authors. In the first place, the fractal dimension of all the sclerophyllous Quercus is lower than 1.6, whereas for marcescent and deciduous Quercus it is over 1.6. The first group includes Q. ilex, Q. rotundifolia, Q. suber, Q. rivas-martinezii, Q. coccifera, Q. estremadurensis, Q. crenata. In this case the difference in the fractal analysis between Q. rotundifolia and Q. coccifera is 0.165647; between Q. coccifera and Q. rivas-martinezii, 0.03631; and between Quercus ilex (Italy) and Q. rotundifolia (Spain), 0.0555751. The inclusion of Q. crenata in the sclerophyllous group confirms its hybridogenous character, as established in Conte et al. (2007). The second group includes the marcescent and deciduous Quercus; within this group there are clear differences between Q. faginea and Q. alpestris, which could provide greater support for maintaining the subsp. alpestris. The comparative fractal analysis between Q. alpestris in the Sierra de las Nieves and Q. gaditana in the Portuguese Algarve reveals significant differences, while the fractal difference between Q. faginea (Guadalajara) and Q. canariensis (Aljibe) is 0.062454. The separate study of deciduous species gives a fractal difference of 0.054552 between the populations of Q. x andegavensis nothosubps, enriquesii in Portugal (north) and Q. pyrenaica in Spain (Sierra Morena). This is due to the hybridisation between Q. pyrenaica and Q. robur subsp. broteroana. In conclusion, the value of the fractal difference highlights the closeness of the kinship between the species.
Fractal analysis: a new method for the taxonomical study of the genus Quercus L. / Análisis fractal: nuevo método para el estudio taxonómico del género Quercus L / Musarella, Cm; Cano-Ortiz, A.; Piñar Fuentes, J. C.; Navas, J.; Vila-Vicoça, C.; Pinto Gomes, C. J.; Vázquez, F. M.; Spampinato, G.; Cano, E.. - (2013), pp. 85-88. (Intervento presentato al convegno VII International Seminar Biodiversity Management and Conservation - “Planning and management of agricultural and forestry resources” tenutosi a Gambarie d‟Aspromonte – RC (Italy) nel 2013, June 2-7).
Fractal analysis: a new method for the taxonomical study of the genus Quercus L. / Análisis fractal: nuevo método para el estudio taxonómico del género Quercus L.
Musarella CM
;Spampinato G.;
2013-01-01
Abstract
A study was made of the genus Quercus in territories in the centre-south of the Iberian Peninsula and southern Italy. Samples were taken from various trees in homogeneous populations selected at each cardinal point: 110 samples were obtained for Spain, 34 for Portugal and 53 for Italy, with a total of 48 sampling points. Sampling was done in areas where there was complete certainty of the existence of a particular taxon, and even of the type, as well as in places where there was some doubt as to the presence of a taxon. In view of the controversy with regard to some species/subspecies of the genus Quercus in the mentioned territories, we used fractal analysis to discriminate the species, a technique that has been little used to the present in Botany, although it is widespread in Medicine. To calculate the fractal dimension we opted for the “box-counting” method integrated in the software Harfa v.5.4.38, as it allows the evaluation of the fractal dimension of structures which are not totally self-similar. Once the fractal values have been obtained, the differences are analysed in order to obtain the minimum value for species for which there is no discrepancy among authors. In the first place, the fractal dimension of all the sclerophyllous Quercus is lower than 1.6, whereas for marcescent and deciduous Quercus it is over 1.6. The first group includes Q. ilex, Q. rotundifolia, Q. suber, Q. rivas-martinezii, Q. coccifera, Q. estremadurensis, Q. crenata. In this case the difference in the fractal analysis between Q. rotundifolia and Q. coccifera is 0.165647; between Q. coccifera and Q. rivas-martinezii, 0.03631; and between Quercus ilex (Italy) and Q. rotundifolia (Spain), 0.0555751. The inclusion of Q. crenata in the sclerophyllous group confirms its hybridogenous character, as established in Conte et al. (2007). The second group includes the marcescent and deciduous Quercus; within this group there are clear differences between Q. faginea and Q. alpestris, which could provide greater support for maintaining the subsp. alpestris. The comparative fractal analysis between Q. alpestris in the Sierra de las Nieves and Q. gaditana in the Portuguese Algarve reveals significant differences, while the fractal difference between Q. faginea (Guadalajara) and Q. canariensis (Aljibe) is 0.062454. The separate study of deciduous species gives a fractal difference of 0.054552 between the populations of Q. x andegavensis nothosubps, enriquesii in Portugal (north) and Q. pyrenaica in Spain (Sierra Morena). This is due to the hybridisation between Q. pyrenaica and Q. robur subsp. broteroana. In conclusion, the value of the fractal difference highlights the closeness of the kinship between the species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
