Nitrogênio e produção primária líquida da Floresta Amazônica utilizando o modelo IBIS

• Ano de defesa: 2012
• Autor(a) principal: Pinto, Luciana Barros
• Orientador(a): Costa, Marcos Heil
• Banca de defesa: Lima, Francisca Zenaide de , Hamakawa, Paulo José , Cuadra, Santiago Vianna
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Meteorologia Agrícola
• Departamento: Agrometeorologia; Climatologia; Micrometeorologia
• País: BR
• Palavras-chave em Português: Climatologia; Hidroclimatologia; Nitrogênio; Floresta amazônica; Modelo IBIS
• Palavras-chave em Inglês: Climatology; Hydroclimatology; Nitrogen; Amazon Forest; IBIS Model
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::METEOROLOGIA::CLIMATOLOGIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1511

Nitrogen availability in terrestrial ecosystem has an important effect on the global carbon cycle and may influence the accumulation of carbon in ecosystems, since these depend on the availability of nutrients such as nitrogen to support the growth of vegetation. A variety of dynamic ecosystem models have been used to gain a better understanding of the relationship between nutrient availability, the C cycle and possible climate change. These models differ significantly in their conceptualization, formulation, parameterization and input data. In this work we used the ecosystem dynamics model IBIS to investigate the influence of nitrogen stress on photosynthesis. The model simulates the cycling of N in soil and plants, allowing the estimation of the values of stocks of this nutrient in each of the compartments of the plant and the assessment of the influence of N deficiency in growth. A comparison of simulated and observed data confirms that IBIS robustly simulates the behavior of net primary production (NPP), biomass, foliar N and soil N. When the vegetation is exposed to nitrogen stress by a reduction of N-leaf fraction, NPP decreases. When atmospheric carbon dioxide was increased, N stress limited the plant s capacity to respond by stimulating photosynthesis in response to the increased concentration of atmospheric CO2. This indicates that inclusion of the relationship between C and N in surface models produces a better simulation of ecosystem behavior. We also observed that there is an increase in N leaf concentration with the age of the forest, which serves as an indicator of increased availability of N for the growth of secondary forest.