Banca de DEFESA: ANDREZZA GOMES ALVES

THE CONSTRUCTION OF A FOREST: ANALYSIS OF THE EVOLUTION OF THE LANDSCAPE OF THE FLONA MÁRIO XAVIER - SEROPÉDICA, RJ

Biogeography; Conservation Units; Anthropogenic ecosystems; Landscape Evolution.  

Landscape, a fundamental category of geographical studies, is the materialization of the relationship of interdependence established between human beings and nature. The intense transformations of so-called natural ecosystems by human action are the result of the evolution of techniques. In this sense, it is possible to observe the multiplication of ecosystems that have been intensely altered by anthropogenic actions and that evolve with characteristics that are very different from the original ones. In the field of Biogeography and Ecology, the novel ecosystems emerge as a theme that addresses the creation, evolution and consolidation of these ecosystems. The objective of this dissertation is to analyze the evolution of the landscape of the area that today comprises the Mário Xavier National Forest (Flona MX), since the creation of the Santa Cruz Forestry Garden in the 1940s to the current context, considering the history of land use and occupation, the restructuring of vegetation through natural and anthropic processes and the contemporary pressures that directly affect the structure and composition of this environment. The specific objectives sought to identify the phytogeographic characteristics of the landscape over the years; identify the agents and processes involved in the changes that occurred in the landscapes over the years; and discuss the possibility of characterizing Flona MX as a novel ecosystem based on the current environmental panorama. Flona MX is a sustainable use conservation unit, with an area of 496 hectares, located in the municipality of Seropédica, in the metropolitan region of Rio de Janeiro. It is one of the few forested fragments in the municipality, home to several species of fauna and flora, including endemic and endangered species. The research was carried out in two methodological stages. The first consisted of analyzing the evolution of the landscape using historical photographs from the 1940s and 1950s, part of the conservation unit's collection, which were identified in the landscape (through fieldwork) and compared to current photographs. The second stage was the preparation of land use and land cover maps for the years 1990, 2000, 2010 and 2020. The land use and land cover classes defined were: forest, non-forest natural formation, urban, non-vegetated area, pasture, agricultural and pasture mosaic and water. The cartographic products were prepared using the QGIS software using data from the MapBiomas platform, collection 7.1. The cartographic analysis aimed to understand the transformations observed in the landscapes over the years. In both stages, fieldwork and bibliographical research were fundamental to understanding the agents and processes responsible for the transformations of the landscape. The discussions of Flona MX as a new ecosystem considered the conceptual structure proposed by Morse et al. (2014) and the examination of the necessary elements after the proposed analyses. The results of the photographic comparison indicated an increase in vegetation cover at the selected points due to natural and anthropogenic processes, making it possible to identify tree individuals in the landscape at different stages of ecological succession. Cartographic resources indicated a 41% increase in the “forest” class between 1990 and 2020, currently representing 39.8% of the total area of the UC. The “agriculture and pasture mosaic” and “pasture” classes also represent a significant part of the land cover, with a total area of 39.4% and 14.4%, respectively. The anthropogenic pressures identified as being of greatest significance are the burning and the suppression of vegetation due to the fragmentation of the UC by the BR-493 and BR-116 highways. The characterization of the area as a new ecosystem has as a future challenge the proof of the functional sustainability of this fragment without anthropogenic action.