Banca de DEFESA: VIVIANE VASCONCELOS CORREA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : VIVIANE VASCONCELOS CORREA
DATA : 22/02/2019
HORA: 14:00
LOCAL: Auditório do NTB
TÍTULO:

Influence of Fire on Vegetation Structure and Dynamics tree shrub in Mancha de Savana Isolated in the Amazon Eastern

PALAVRAS-CHAVES:

Amazon Savannahs. Shrub-tree vegetation. Structure. Dynamics.

PÁGINAS: 65
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

The isolated savanna in Alter do Chão is part of the Amazon Savannah typology and is the Amazon savannah area where some studies has been done. Overall, fire has caused changes in the populations and communities of savannas in Alter do Chão, through direct or indirect effects. However, it is not yet clear how the shrub-tree vegetation is affected, because monitoring studies had not been carried out until then. The objective of this study was to evaluate the influence of fire on the structure of shrub-tree vegetation in an isolated Amazon Savanna in Alter do Chão - PA. Simultaneously, to analyze the variations that occurred in this vegetation in the interval of ten years, considering the fire as main agent of change. The study area is located between the city of Santarém and the district of Alter do Chão, in the State of Pará. In 2008, two permanent plots of 1 ha each were located in areas with distinct fire occurrences, defined as SF (Savannah with fire) and SSF (Savannah without fire). Floristic
inventory of shrub-tree individuals with DAP ≥ 10 cm was performed, and these plots were evaluated again in 2018 providing information on structural changes and vegetation dynamics. Another 12 plots of (0.25 ha) were installed and all shrub-tree individuals with height from 2 meters high and diameter (D30) 5 cm were measured. In these plots considering an area of 1 m x 250 m, individuals with 5 cm ≤ D30 ≥ 2 cm were sampled. The fire regime significantly influenced the current structure of shrub-tree vegetation, reducing density and basal area of
individuals. The diversity of species, density and basal area are higher in the savanna area with lower incidence of fire. Mortality rates exceeded recruitment rates in the Alter do Chão savannah, both in SF and SSF. The negative balance between these rates did not change the occurrence of species with high density and good survival, which can stand out and dominate the environment. In SF the species Salvertia convallariodora, Himatanthus drasticus and Anacardium occidentale are the most important, while in SSF the species Salvertia convallariodora, Qualea grandiflora and Pouteria ramiflora are the most important. During 10 years, despite the changes, the savanna presented high stability, maintaining its structure and diversity of species, independent of the frequency of fire.

MEMBROS DA BANCA:
Externo ao Programa - 1520271 - JOAO RICARDO VASCONCELLOS GAMA
Presidente - 1794276 - JOSE MAURO SOUSA DE MOURA
Externo à Instituição - SUSAN ARAGÓN - UFOPA
Externo à Instituição - TOMAS FERREIRA DOMINGUES - USP