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
;
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.
2013
978-88-89367-87-2
Se afronta el estudio del género Quercus en territorios del centro-sur de la Península Ibérica y sur de Italia. Para ello se seleccionaron poblaciones homogéneas y se tomaron muestras de cada punto cardinal de diferentes árboles, obteniéndose 110 muestras en España, 34 en Portugal y 53 en Italia, con un total de 48 puntos de muestreo. Los muestreos fueron realizados en áreas donde se tiene la plena seguridad de la existencia de un determinado taxón, e incluso del tipo, así como en aquellos lugares a los que se les adjudicó la existencia de un taxón de manera dudosa. Ante la controversia existente respecto a algunas especies/subespecies del género Quercus en los territorios mencionados, empleamos para discriminar las especies el análisis fractal, poco utilizado hasta el momento en Botánica, pero suficientemente en Medicina. Hemos optado, para el cálculo de la dimensión fractal, del método “box-counting”, integrado en el software Harfa v.5.4.38, ya que ofrece la posibilidad de evaluar la dimensión fractal de estructuras que no son totalmente autosimilares. Una vez obtenidos los valores fractales se analizan las diferencias, con el objetivo de obtener el valor mínimo para especies en las que no existe controversia entre los autores. En primer lugar la dimensión fractal de todos los Quercus esclerófilos es inferior a 1.6, mientras que los Quercus marcescentes y caducifolios es superior a 1.6. En el primer grupo se incluyen: Q. ilex, Q. rotundifolia, Q. suber, Q. rivas-martinezii, Q. coccifera, Q. estremadurensis, Q. crenata. En este caso la diferencia en cuanto al análisis fractal entre Q. rotundifolia y Q. coccifera es de 0.165647, entre Q. coccifera y Q. rivas-martinezii es de 0.03631, y entre Quercus ilex (Italia) y Q. rotundifolia (España) es de 0.0555751. La inclusión de Q. crenata en el grupo de los esclerófilos confirma su carácter hibridógeno establecido en Conte et al. (2007). En el segundo grupo se incluyen los Quercus marcescentes y caducifolios; dentro de este grupo se observan claras diferencias entre Q. faginea y Q. alpestris, lo que podría ahondar en la idea de mantener la subsp. alpestris. En el análisis fractal comparativo entre Q. alpestris de Sierra de las Nieves y Q. gaditana del Algarve portugués se observan fuertes diferencias. Mientras Que la diferencia fractal entre Q. faginea (Guadalajara) y Q. canariensis (Aljibe) es de 0.062454. Al estudiar por separado las especies de caducifolios, observamos una diferencia fractal de 0.054552 entre las poblaciones de Q. x andegavensis nothosubps, enriquesii Portugal (norte) y Q. pyrenaica de España (S. Morena). Este hecho es debido a la hibridación entre Q. pyrenaica y Q. robur subsp. broteroana. En conclusión el valor de la diferencia fractal pone de manifiesto el grado de parentesco entre las especies.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12318/62593
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