Banca de DEFESA: AMANDA DOMINGUES MARTINS FREITAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : AMANDA DOMINGUES MARTINS FREITAS
DATA : 23/01/2020
HORA: 09:00
LOCAL: Salão Nobre
TÍTULO:

ECOLOGICAL FUNCTIONS OF POLYCHETES (ANNELIDA; POLYCHAETA) ALONG TROPICAL ESTUARIES

PALAVRAS-CHAVES:

Ecosystem functioning, Functional traits, Estuarine, Macroinvertebrates

PÁGINAS: 71
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

Ecological functions are important for maintaining ecosystems and can be defined as

the roles that organisms played in the environment. The functional approach allows a

better understanding on ecosystem functioning over other approaches (e.g. taxonomic

classification). Functions can be studied through the functional traits of individuals and

ecosystem properties (e.g. resilience) depend on their distribution and abundance over

time and space. However, several studies have used arbitrary functional traits that are

not necessarily associated with the functioning of ecosystems. Many studies in estuarine

ecosystems investigate the distribution of benthic macrofauna and spatial and / or

temporal patterns. However, the distribution of the functions performed by macrofauna

throughout this system is still little known. In the present work, our hypothesis is that

the functional composition of benthic macrofauna does not change significantly over

gradients and at different periods, although the taxonomic composition changes, since

taxa may have similar sets of characteristics to perform a given function. We used a lot

of data from 3 estuaries of Todos os Santos Bay along a salinity gradient with 10 or 11

sampling stations in the least 4 different times for each estuary. First, the important

ecological functions for the estuarine environments and the combinations of functional

traits directly related to the ecological functions were surveyed. Subsequently, potential

differences in the distribution of functions between estuarine salinity zones were tested

over the years. The ecological functions considered important for the estuaries were

bioturbation, fragmentation of organic matter, stabilization of sediment, nutrient cycling

and secondary production. A total of 11 categories of traits were used to describe the

ecological functions mentioned above, including: mobility, type of movement, feeding

mode, food deliver mode, presence of jaw, sedimentary compartment, body size,

reproduction mode, age of first reproduction, life span and fecundity rate. In general,

functional redundancy was identified for the traits associated with sediment bioturbation

and nutrient cycling in the finer-grained marine regions, while in the upstream estuaries

with coarse-grained sediment it was identified traits mainly associated with

fragmentation function of organic matter. The abundance of organisms with traits

associated with sediment stabilization was low and the feature sets associated with

secondary production appear to increase as salinity decreases. Not all functions were

maintained along the estuarine gradient, due to the absence of similar traits capable of

compensating for the loss of polychetes in certain regions. The ecological functions

performed by polychetes showed significative differences between salinity zones (i.e.,

Jaguaripe estuary), as well as interactions between sampling years and salinity zones

(i.e., Paraguaçu estuary), and years (i.e.,Subaé estuary). The results of this study

contribute to understand the functioning and management of estuarine ecosystems.

Empirical studies are necessary to test the relationship of the described functional traits

with the mentioned ecological functions in order to measure the real potential of the

functional traits of organisms in the functioning of ecosystems.

MEMBROS DA BANCA:
Presidente - 1522389 - FRANCISCO CARLOS ROCHA DE BARROS JUNIOR
Interno - 2997144 - IGOR CRISTINO SILVA CRUZ
Externo ao Programa - 361.032.948-35 - JOÃO BOSCO LEITE GUSMÃO JUNIOR - UFPR