Banca de DEFESA: ANE CAROLINE CANDIDO FIRMO DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANE CAROLINE CANDIDO FIRMO DE OLIVEIRA
DATE: 17/12/2025
TIME: 09:00
LOCAL: meet.google.com/ahh-ahzg-csv
TITLE:

PRECIPITATION PULSES AND CO₂ BALANCE IN A CAATINGA AREA: A CASE STUDY

KEY WORDS:

Eddy Covariance, Ecosystem services, Semi-arid

PAGES: 39
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SPECIALTY: Micrometeorologia
SUMMARY:

This study investigated the influence of precipitation pulses on the carbon balance in a preserved Caatinga area located in the Açu National Forest (RN). The measurements, carried out between July 2023 and June 2024, used the eddy covariance technique to estimate the net CO₂ exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (Reco). Two rainfall events were identified during the dry period, one in November (P1) and the other in December 2023 (P2). The results demonstrated that the greatest carbon sequestration fluxes occurred immediately after rainfall events, especially after the second pulse, when NEE went from -1.26 to -1.40 g C m⁻² d⁻¹ and GPP increased from 2.04 to 2.29 g C m⁻² d⁻¹. These variations were accompanied by an increase in relative humidity and a reduction in vapor pressure deficit (VPD), favoring an increase in photosynthetic efficiency. In contrast, Reco showed a marked increase immediately after P2, indicating reactivation of biological processes in the soil and vegetation. These results highlight the strong dependence of Caatinga metabolism on intraseasonal water availability, reinforcing that rainfall pulses, even in isolation, are crucial in ecophysiological reactivation and in the regulation of carbon exchange in semi-arid ecosystems. It is concluded that the inclusion of rainfall variability in carbon balance models is essential to improve projections on the resilience of the Caatinga biome in the face of climate change.

COMMITTEE MEMBERS:
Presidente - ***.400.082-** - GABRIEL BRITO COSTA - UFOPA
Interno - 2086472 - BERGSON GUEDES BEZERRA
Interno - 1752417 - CLAUDIO MOISES SANTOS E SILVA
Interna - ***.425.702-** - KEILA RÊGO MENDES - UFPE
Externo à Instituição - RAONI AQUINO SILVA DE SANTANA - UFOPA