Banca de QUALIFICAÇÃO: ANA LUIZA BEZERRA DA COSTA SARAIVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANA LUIZA BEZERRA DA COSTA SARAIVA
DATE: 23/05/2024
TIME: 14:00
LOCAL: Link - https://meet.google.com/ixs-rwsu-hdj
TITLE:

Carbon flow and the mitigating potential of the regulatory ecosystem service in caatinga areas

KEY WORDS:

Carbon cycle; caatinga; semiarid; regulatory service in caatinga; mitigation.

PAGES: 89
BIG AREA: Ciências Humanas
AREA: Geografia
SUMMARY:

This study examines carbon flux in preserved caatinga areas at the Ecological Station of Seridó in Serra Negra do Norte/RN during 2014 and 2015. Understanding the biogeochemical carbon cycle is crucial in the face of global climate changes, as it facilitates the development of effective mitigation actions. Identifying the potential of ecosystem regulation services requires an integrated view of the landscape, considering the complex interaction between atmosphere, water, soil, biodiversity, and society in the Caatinga areas. This work employed a micrometeorological tower to measure gross primary production, respiration, and net primary production, in addition to climate data provided by the National Observatory of Water and Carbon Dynamics in the Caatinga Biome. Precipitation data were collected by the National Water Agency and the Agricultural Research Company of RN. Based on the annual total precipitation, the years 2014 and 2015 were classified as rainy and normal, respectively. January 2014 recorded 3 mm of rain distributed over two days, with a daily average of net primary production at -2.1 gCm-2, acting as a significant carbon sink. In 2013, 59 mm in November and 74.2 mm in December were registered, totaling 133.2 mm distributed over 6 days in 3 weeks, which boosted leaf production and the gradual increase of photosynthesis in the early months of 2024. However, January 2015, despite receiving 65.2 mm of rain, the absence of rain in December 2014 negatively impacted the photosynthesis process. It becomes evident that the annual carbon flux cycle in the semiarid region of Potiguar begins in December and continues into January, a warm period with sporadic rains, which is little explored in the literature on carbon balance in Rio Grande do Norte. During the rainy season, from February to May, with the foliage partly reestablished, the water volume in the system, which influences the carbon flux, is determined by the rains of the month. Despite variations in the total days, weeks, and accumulated precipitation over the months, with intense biological activity leading to increased respiration, the rainy season of the two study years proved to be a robust carbon sink. It is concluded that the studied caatinga fragment in the Potiguar semiarid is an annual CO2 sink, with the highest stock values occurring in months with the best relation between total volume and daily and weekly distribution, highlighting the importance of the warm period with sporadic rains for the annual carbon cycle. Therefore, annual carbon flux studies for areas in the Potiguar semiarid should consider the annual climatic cycle that starts in December and influences photosynthesis production in January of the following year. The annual seasonality is directly linked to the annual carbon balance and the phenological dynamics of the caatinga. As a CO2 sink, even under different annual climatic conditions, the caatinga offers a crucial ecosystem service of atmospheric regulation that can contribute to climate change mitigation strategies and the conservation of this unique ecosystem, which must be preserved and have degraded areas restored and protected. This important ecosystem service can boost local development through projects and programs for payment for environmental services, allowing preserved caatinga areas to help Brazil achieve its national and international carbon stock targets, as well as participation in the international carbon market. For this, Brazil needs to make caatinga areas a priority in combating global climate changes.

COMMITTEE MEMBERS:
Presidente - 2966354 - DIOGENES FELIX DA SILVA COSTA
Interno - 1503011 - LUTIANE QUEIROZ DE ALMEIDA
Externo ao Programa - 2086472 - BERGSON GUEDES BEZERRA - UFRNExterno ao Programa - 1752417 - CLAUDIO MOISES SANTOS E SILVA - UFRNExterno ao Programa - 3357734 - MAX WENDELL BATISTA DOS ANJOS - UFRN