Banca de DEFESA: ÍCARO GUEDES DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ÍCARO GUEDES DA SILVA
DATE: 27/02/2026
TIME: 09:00
LOCAL: Google Meet
TITLE:

Soil-relief-vegetation relationship in altitudinal gradients in a mountainous environment in the Brazilian semi-arid region.

KEY WORDS:

Escarpments; morphogenesis; pedogenesis; dryland vegetation; dissolution basins.

PAGES: 96
BIG AREA: Ciências Humanas
AREA: Geografia
SUMMARY:

The Caatinga is a biome characterized by semi-arid climatic conditions, marked by irregular rainfall, high temperatures, and prolonged dry periods, which impose strong constraints on the development of vegetation cover. However, the spatial organization and physiognomic diversity of vegetation within this domain cannot be explained solely by climate, since local geoenvironmental controls—such as relief, soils, and lithology—play a fundamental role in landscape differentiation. In this context, this dissertation aimed to analyze soil–relief–vegetation interactions along altitudinal gradients in the Brazilian semi-arid region, using the Serra do Lima, located in the municipality of Patu, Rio Grande do Norte State, as the study area. Serra do Lima is a granitic residual relief of the inselberg type, developed on Neoproterozoic rocks of the Itaporanga Suite and inserted within the geomorphological context of the Northern Sertaneja Depression. The research was based on an integrated geoenvironmental approach, combining bibliographic review, 

analysis of cartographic databases, and the production of thematic maps of geology, geomorphology, soils, vegetation, and land use and occupation within a Geographic Information System (GIS) environment, using QGIS software. Fieldwork was also conducted, including geomorphological reconnaissance, vegetation surveys, and morphological description of soil profiles across different landscape compartments.

The results indicate that relief compartmentalization and pedogenetic dynamics exert strong control over the distribution and structure of vegetation. In summit areas and sectors with extensive rock outcrops, morphogenetic processes predominate, resulting in shallow, discontinuous soils frequently associated with lithic contact, which favor the development of shrub, grass–woody formations, and rupestrian fields composed of species adapted to water stress and edaphic limitations. Conversely, on slopes and areas with lower gradients, where flow convergence and material accumulation occur, deeper and more evolved soils were identified, allowing the establishment of vegetation with greater structural complexity, dominated by arboreal and subarboreal physiognomies. From a pedological perspective, the identification of relatively deep soils with high clay contents in some landscape sectors reveals the significant action of chemical weathering processes, even under semi-arid conditions and over granitic parent material. These findings contrast with the expectation of the exclusive predominance of shallow and poorly developed soils in semi-arid mountainous environments, highlighting the importance of geomorphological and structural controls on soil genesis. Vegetation analysis showed that the official classification of the Caatinga based on the savanna–steppe concept, although relevant at regional scales, has limitations in explaining the physiognomic variability observed in mountainous areas. The integrated approach adopted in this study allowed the recognition of distinct vegetation typologies closely linked to physical substrate conditions, reinforcing the need to incorporate geoenvironmental controls in landscape interpretation. It is concluded that Serra do Lima exhibits high environmental complexity and functions as an ecological refuge within the Brazilian semi-arid region. Understanding soil–relief–vegetation interactions proved essential for interpreting local landscape dynamics and provides important support for environmental planning, biodiversity conservation, and the sustainable use of mountainous environments in the Caatinga domain.

COMMITTEE MEMBERS:
Presidente - 1997952 - DAVI DO VALE LOPES
Interno - 3289864 - ABNER MONTEIRO NUNES CORDEIRO
Interno - 3342435 - ANTONIO RODRIGUES XIMENES NETO
Externo à Instituição - DEMETRIO ANGELO LAMA ISMINO
Externo à Instituição - FREDERICO DE HOLANDA BASTOS