Banca de QUALIFICAÇÃO: REGINA LÚCIA GUIMARÃES NOBRE

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : REGINA LÚCIA GUIMARÃES NOBRE
DATA : 24/05/2019
HORA: 18:00
LOCAL: Sala de reuniões - DECOL
TÍTULO:

 

EXTERNAL AND INTERNAL NUTRIENT SOURCES CAN AFFECT FRESHWATER QUALITY AND BIODIVERSITY

PALAVRAS-CHAVES:

Nutrient cycles, land use, subsidy, nonpoint source polution, carcass

PÁGINAS: 86
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

Nutrient cycling is a fundamental ecosystem service as it provides an adequate balance of elements that are necessary for life. In freshwaters, the balance of nitrogen (N) and phosphorus (P) are of special interest as they often limit or control primary production and biomass formation. While the availability of these nutrients is fundamental for the maintenance of productivity and fertility of freshwaters, their excess can lead to eutrophic conditions that are associated with impaired water quality. Furthermore, changes in nutrient concentrations are usually associated with changes in structure and composition of pelagic communities. The nutrient balance in freshwaters can potentially be affected by a variety of biotic and abiotic, external and internal pathways. In this thesis, two frameworks were explored, a spatial framework focused on external processes, where we investigated the effects that different aspects of land use (i.e. type, extent) have on biotic and abiotic properties of freshwater systems and how such effects may interact with climate and lake and watershed geomorphology. The second approach was a temporal framework focused on internal processes related to nutrient cycling where we assessed whether a fish population with high biomass and growth rate is a source or sink of nitrogen and phosphorus to the pelagic zone of a temperate eutrophic lake, at various time scales ranging from days to years. More specifically, on chapters one to three of this thesis, we evaluated the effects of land use and its interactions with climate, lake and catchment area physical traits, and local habitats on: 1) the concentrations of nutrients on water; 2) the abundance and dominance of total cyanophyceae as well as some of its components such as N-fixing and potentially toxic species to total phytoplankton biomass and 3)  the patterns of diversity of phytoplankton and zooplankton communities. To understand the role of internal processes on nutrient availability within freshwater bodies, on the chapter four of this thesis, the part of fish as nutrient sources or sinks of nutrients is explored.

MEMBROS DA BANCA:
Interno - 1714892 - ADRIANO CALIMAN FERREIRA DA SILVA
Presidente - 1434166 - LUCIANA SILVA CARNEIRO
Interna - 1914239 - MIRIAM PLAZA PINTO
Externo à Instituição - RAFAEL DETTOGNI GUARIENTO - UFMS