Banca de DEFESA: FERNANDA JUCÁ DE MEDEIROS ARAÚJO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FERNANDA JUCÁ DE MEDEIROS ARAÚJO
DATE: 29/05/2020
TIME: 09:00
LOCAL: Sala 213 do CTEC/UFRN
TITLE:

SIMULATION OF A TROPHIC WEB IN A SEMI-ARID RESERVOIR IN VARYING SETS OF NUTRIENT SUPPLY AND FISHING EFFORT

KEY WORDS:

Trophic web. Ecopath. Ecological modeling. Ecosystem approach.

PAGES: 41
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUMMARY:

Reservoirs are essential aquatic ecosystems, especially in semiarid tropical regions, with a high scarcity of water resources for human consumption. These environments are subject to anthropic disturbances (fishing, pollution, consumption) or naturally caused by climate characteristics, such as rising temperatures and long periods of drought. These disturbances could lead to changes in the structure and functioning of these ecosystems, as well as in the degradation of the water quality. Understanding the control mechanisms of the food webs can support management decisions aimed at improving water quality. This work aimed to quantify the trophic web of a small reservoir in the Brazilian semiarid to describe the main mechanisms (drivers) that act in the structure and dynamics of this ecosystem. We used the Ecopath with Ecosim software to quantify the trophic web of the reservoir located at the Seridó Ecological Station (ESEC) in the semiarid region of Northeast Brazil. We made three models with the same data set (May 2012 to April 2014): a classic annual model and two monthly models with some differences between them. Time simulations were performed on the two monthly models to mimic the dynamics of nutrients and plankton compartments. The simulations were tested with two forcing functions  (phosphorus and radiation) and under different impact scenarios (changes in the nutrient load and removal of fishes species). The modeling results indicated that the ESEC reservoir is an ecosystem dependent most of the detritus chain, with high primary productivity, and low resilience. Although the key species are top predators, they do not seem to influence much the dynamics of plankton, and bottom-up forces are controlling the food web, corroborating outputs of a biomanipulation experiment carried out in the reservoir at the same time as the data set collection.

BANKING MEMBERS:
Externo à Instituição - LUIS ARTUR VALÕES BEZERRA
Presidente - 1177742 - RONALDO ANGELINI
Interna - 1764855 - VANESSA BECKER