Banca de DEFESA: ALEXANDRE DOS SANTOS MEDEIROS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ALEXANDRE DOS SANTOS MEDEIROS
DATA : 24/09/2019
HORA: 13:00
LOCAL: Sala Waldemar Mendes, n°39, Departamento de Solos
TÍTULO:

Influence of land use on the pattern of soil organic matter and carbon stock, Itatiaia National

Park, RJ

PALAVRAS-CHAVES:

Ecological Succession. Phytomass. Organic matter. Phytosociology.

PÁGINAS: 262
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
RESUMO:

In Brazil, the conversion of natural areas to agricultural areas corresponds to 75% of CO2 emissions. Currently, the Amazon and Cerrado Biomes have the highest conversion rate because they are the current Brazilian agricultural frontier. However, little is known about the impacts and resilience of ecosystems belonging to the Atlantic Forest Biome, which was profoundly altered during the first productive cycles of the country. To clarify such issues, areas were selected in the Itatiaia National Park (PNI), in the State of Rio de Janeiro, as the PNI shelters, besides numerous preserved ecosystems, secondary forest fragments in different stages of ecological succession, as well as unmanaged pasture areas, a landscape commonly observed in the Middle Valley region of Paraíba do Sul. Given this scenario of profound degradation, reduction of environmental services and ignorance of ecological processes, studies are urgently needed to enable such understanding, allowing interventions capable of reestablishing the environmental services of these communities, especially the sequestration and storage of C. Therefore, soil samples were collected from different successional stages of forest and in unmanaged pasture, being determined the natural fertility, the chemical and particle size fractionation of the organic matter (MOS), stock and origin of C. In addition to the edaphic variables, samples of pasture and different phytomass were also collected. forest compartments, being used non-destructive methods to quantify the phytomass and the stock of C in the tree forest layer. In order to obtain ecological data regarding the structure of forest communities, permanent plots were installed at different successional stages, and a floristic study and structural characterization of the communities were carried out. As a general result we found that: local soils have low natural fertility; MOS has greater stability as advanced successional stages; carbon stocks in early-stage soils and phytomass are lower than advanced stages; pastures have higher values of C stock in the soil, but predominates C from forest origin from the depth of 10 cm; forest structure and diversity are similar to those generally observed in the biome; The use of multivariate statistical techniques allowed the construction of discriminant functions capable of qualitatively classifying similar communities according to carbon stock capacity. These results allowed us to conclude that: secondary forests are more efficient in carbon storage than pastures, indicating the importance of preservation and recovery of these formations in the Paraíba do Sul Middle Valley, and discriminating functions are important tools for classification of priority areas.

MEMBROS DA BANCA:
Externo à Instituição - ALEXANDER SILVA DE RESENDE
Interno - 2213075 - EVERALDO ZONTA
Externo à Instituição - FABIANO DE CARVALHO BALIEIRO
Externo ao Programa - 1855169 - MARCELO DA COSTA SOUZA
Presidente - 1060711 - MARCOS GERVASIO PEREIRA