Banca de QUALIFICAÇÃO: DANILO GOMES DE OLIVEIRA
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : DANILO GOMES DE OLIVEIRA
DATE: 28/03/2024
TIME: 08:00
LOCAL: Videoconferência - https://meet.google.com/ypb-znjq-ppo
TITLE:
Greenhouse gas emission flows due to land use change in the Atlantic Forest Biome
KEY WORDS:
Agroforestry system. Cocoa monoculture. Cover crops. Carbon dioxide. Methane. Nitrous oxide.
PAGES: 35
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:
Greenhouse gas (GHG) emissions from land use change represent a significant source of environmental pollution. The conversion of conservation areas, such as native Atlantic Forest, in agricultural production areas increases GHG emissions. On the other hand, agriculture when carried out under conservation pillars is considered a GHG drain. In this way, soil management has an important role in the carbon and GHG cycle and must be contracted to increase carbon in the soil and reduce emissions of these gases into the atmosphere. In this sense, the study was developed with the objective of evaluating GHG flows as a function of land use change and the relationship with the physical and chemical attributes of the soil. The study was carried out in the experimental area of CEPLAC in Ilhéus, BA. The treatments consisted of cocoa cultivation systems that include land use change: agroforestry system with 40 years of implementation (cocoa trees with rubber trees and cocoa trees with caja trees) and a full-sun cocoa cultivation system with four years of implementation, intercropped with cover crops (brachiaria; spontaneous vegetation, forage peanuts and uncovered soil). Flux monitoring was carried out during two seasons, dry and rainy, with semi-annual sampling considering periods of higher and lower rainfall incidence. Gas collection occurred every three days, completing readings over fifteen days. Precipitation, average air temperature, soil temperature, and soil samples from the 0-10 cm layer for ammonium (NH4+), nitrate (NO3-), pH, and water-filled porosity (WFP) analysis were recorded. The dry period had low precipitation, totaling 65.5 mm, with temperatures ranging from 17.6°C to 27.3°C, averaging 21.9°C. The rainy period had high precipitation, reaching 252.1 mm, and temperatures between 20.4°C and 29.5°C, averaging 24.1°C. The difference between the averages of the rainy and dry periods was 2.2°C. CO2-C flux varied between -0.10 and 4.76 g m-2 h-1 during the experiment, ranging from -0.10 to 4.76 g m-2 h-1 in the rainy period and -0.059 to 3.46 g m-2 h-1 in the dry period. CH4-C flux ranged from -36.14 mg m-2 h-1 to 39.92 mg m-2 h-1 during the research. In the dry season, monthly CH4-C flux was -72.56 to 20.81 mg m-2 h-1, and in the rainy season, it was -36.14 to 39.92 mg m-2 h-1. Monthly N2O-N flux varied between -0.58 ng m-2 h-1 and 27.83 ng m-2 h-1 during the research. In the dry season, monthly N2O-N flux was 0.31 to 27.83 ng m-2 h-1, and in the rainy season, it was -0.58 to 19.96 ng m-2 h-1. In the full sun cacao system with forage peanuts showed the highest average negative methane flux, with values of -8.14 mg m-2 h-1. For treatments with brachiaria, spontaneous vegetation, and cocoa SAF with rubber trees, negative values -2.35, -1.47 and -2.291 mg m-2 h-1 of methane were observed, respectively. Only the native Atlantic Forest fragment had a positive flux, with a value of 0.300 mg m-2 h-1. For nitrous oxide, the full-sun system with brachiaria presented the highest average value, 10,856 ng m-2 h-1, followed by the treatment with forage peanuts and spontaneous vegetation, with 10,473 and 8,630 ng m-2 h-1, of nitrous oxide, respectively. The Atlantic Forest fragment had a positive flow with a value of 7,562 ng m-2 h-1. In relation to CO2, the SAF of cocoa with erythrina and the native forest fragment presented the highest average values, 0.951 and 0.733 g m-2 h-1, respectively, while the SAF of cocoa with rubber tree and cocoa in full-sun with forage peanuts presented the lowest values, 0.343 and 0.459 g m-2 h-1, of CO2, respectively.
COMMITTEE MEMBERS:
Presidente - 1099329 - JOAO CARLOS MEDEIROS
Interno - 3026285 - RAFAEL HENRIQUE DE FREITAS NORONHA
Interna - 3025873 - KHETRIN SILVA MACIEL
Externo à Instituição - CASSIO JARDIM TAVARES - IFGO
Externa à Instituição - MARCIA THAIS DE MELO CARVALHO
Externo à Instituição - BRUNO JOSE RODRIGUES ALVES - UFRRJ
Externo à Instituição - PAULO CESAR LIMA MARROCOS - UESC-BA
Externo à Instituição - LUCAS FELISBERTO PEREIRA - IFGO