Hydrological causes and consequences of environmental changes in wetlands in the Federal Distric

Abstract

The integrity of the Cerrado is essential for national and continental ecohydrological functioning. The campos limpos, especially of wetlands, are formations of extreme priority for conservation of the water functioning of the Cerrado. The phenomenon of densification of woody plants, shrubs, or trees, has been frequently observed in Cerrado grassland physiognomies. However, the possible environmental conditions that cause the densification of woody plants, as well as the probable consequences of this phenomenon are still poorly understood. The study model that the present work proposes will be the colonization and densification of the shrubby species Baccharis retusa BC. (Asteraceae) and Trembleya parviflora (D.Don) Cogn. (Melastomataceae) in wetlands of conservation units in the Federal District (DF). B. retusa and T. parviflora are native Cerrado species, but their growth and densification have visibly altered the landscape, especially the grassland formations. T. parviflora has been reported as a species widely present in wetlands that have undergone some type of degradation. While congeneric species of B. retusa are considered invasive species in the North American and European continents, indicating the need to investigate ways of early detection and management of this species here in Brazil. Remote sensing has become increasingly important for ecological monitoring, both in understanding the factors, processes, and detection of invasive plants and in assessing the impacts on ecosystem functioning. Therefore, the present work proposes to evaluate the colonization of wetland areas by B. retusa and T. parviflora, as well as the changes in the hydrology of these areas, using orbital and airborne remote sensing techniques. The study has the following specific objectives: i) To develop a methodology for remote detection and monitoring of these species to make it available to managers of conservation units in the Federal District; ii) To investigate which environmental factors and disturbances (topography, fire history, adjacent urban occupation, and climatic anomalies) may be related to the colonization and establishment of these species in wetlands of conservation units in the Federal District; iii) To evaluate possible physical and chemical changes in the soil resulting from the invasion of B. retusa and T. parviflora. In methodological terms, the analyses will be based on field data collection and on the survey of aerial images with an Unmanned Aerial Vehicle (UAV), embarked with a multispectral camera. Among the expected results, we highlight the generation of vegetation indices and the mapping of invasive species, as well as a better understanding of the human, ecological and hydrological factors responsible for this landscape. (AU)