Anatomia ecológica e dendrologia de Eugenia sonderiana O. Berg e Eucalyptus saligna sm. na Serra do Cipó MG

Abstract

Studies of the wood are valuable for many areas of botany, such as systematic and anatomy, being this last one, the focus of this work. The wood is able to record the environmental variations expressed through the cambium activity, allowing the retrievement of climate data of earlier times. Individuals from a plantation of Eucalyptus saligna located in the Parque Nacional da Serra do Cipó (PARNA Serra do Cipó), and native species Eugenia sonderiana, located in the vicinity of this plantation had their wood sampled and prepared for histological slides. Transverse, longitudinal tangential and radial sections, besides macerated material were observed. The length, wall thickness, lumen diameter and width of the vessel elements and fibers were measured and the density of these cells and ray parenchyma was calculated. Discs of wood were polished in order to view and count the growth rings, which were related to the climatological data of the last 10 years in the region. The anatomical structure of Eucalyptus saligna is different from that of individuals from populations native to Australia and introduced in the state of São Paulo. Long-term drought is believed to be the variable responsible for these differences. Eugenia sonderiana characters shows that it is better suited to the environment of Serra do Cipó than Eucalyptus saligna, because it has diagnostic features of the environment. The spatial disorganization of individuals in the plantation of Eucalyptus saligna was explained by the presence of resprouting from cuts, falls and lignotuber, besides seed propagation. After polishing the samples, we observed that both species recorded growth rings. The circumference of individuals of Eugenia sonderiana is equivalent to the circumference of the youngest Eucalyptus saligna individuals, although they age-match the individuals with greater circumference, indicating that the native species develops slower than the exotic one