ABSTRACT
Nitrophilous communities dominated by Glebionis coronaria and Glebionis discolor in the European Mediterranean area were studied. The nomenclature was corrected according to the current taxonomy, following the International Code of Phytosociological Nomenclature (ICPN). The statistical analysis revealed six new associations and one subassociation, with four in Spain, one in Greece, and one in Italy. Additionally, a subassociation of high relevance due to its endemic character was identified. These grasslands exhibit requirements for organic matter and other edaphic nutrients that are closer to those of Malva neglecta communities than to those of Hordeum murinum subsp. leporinum. We confirmed the published syntaxon with the rank of Resedo albae-Glebionenion coronariae suballiance and its subordination to the Malvion neglectae alliance, and we established the type association for this suballiance. Sisimbrietalia officinalis J. Tüxen in Lohmeyer et al. 1962 em. Rivas-Martínez, Báscones, T. E. Díaz, Fernández-González & Loidi 1991. Stellarietea mediae Tüxen, Lohmeyer & Preising ex von Rochow 1951.
ABSTRACT
The study of the forest in rainy environments of the Dominican Republic reveals the presence of four types of vegetation formations, clearly differentiated from each other in terms of their floristic and biogeographical composition, and also significantly different from the rainforests of Cuba. This leads us to propose two new alliances and four plant associations located in northern mountain areas exposed to moisture-laden winds from the Atlantic: All. Rondeletio ochraceae-Clusion roseae (Ass. Cyatheo furfuracei-Prestoetum motanae; Ass. Ormosio krugii-Prestoetum montanae); and All. Rondeletio ochraceae-Didymopanion tremuli (Ass. Hyeronimo montanae-Magnolietum pallescentis; Hyeronimo dominguensis-Magnolietum hamorii). We pay special attention to the description of cloud forest types, since they have a high rate of endemic species, and therefore there are endemic habitats, which need special protective actions. Therefore, we apply the Shannon diversity index to characteristic, companion, non-endemic, and endemic species. As result, the association Ormosio krugii-Prestoetum montanae has a Shannon_T = 2.4 and a value of Shannon_E = 0, whereas the other 3 associations have a better conservation status with Shannon values in all cases > 0: This is due to a worse conservation status of the Eastern Cordillera, in comparison with the Central Cordillera and Sierra de Bhaoruco. Due to human activity, some areas are very poorly conserved, as evidenced by the diversity index and the presence of endemic tree and plant elements. The worst conserved in terms of the relationship between characteristic plants vegetation (cloud forest) in areas with high rainfall are in the Dominican Republic, along with its floristic diversity and state of conservation. This study has made it possible to significantly increase the botanical knowledge of this important habitat.
ABSTRACT
The fractal dimension (FD) is calculated for seven species of the genus Quercus L. in Calabria region (southern Italy), five of which have a marcescent-deciduous and two a sclerophyllous character. The fractal analysis applied to the leaves reveals different FD values for the two groups. The difference between the means and medians is very small in the case of the marcescent-deciduous group and very large when these differences are established between both groups: all this highlights the distance between the two groups in terms of similarity. Specifically, Q.crenata, which is hybridogenic in origin and whose parental species are Q.cerris and Q.suber, is more closely related to Q.cerris than to Q.suber, as also expressed in the molecular analysis. We consider that, in combination with other morphological, physiological and genetic parameters, the fractal dimension is a useful tool for studying similarities amongst species.
