Fotossínteses em cenários de mudanças climáticas: adaptação de modelo para a produtividade potencial da cana-de-açúcar

• Autor(a) principal: Renato, Natalia dos Santos
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5228
• topic: Mudanças climáticas; Modelagem; Cana-de-açúcar; Climate change; Modeling; Sugar cane; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::AGROMETEOROLOGIA

It has been observed in the last years an increasing concern about agriculture crop s responses due to the higher temperature and CO2 concentration in the atmosphere. What made this job even harder were the photosynthesis models which weren t developed considering a higher CO2 concentration effect on the crop productivity. In order to simulate potential productivity of future scenarios, a model was analyzed with adjustments to the climate change, which sticks out for including biochemical reactions with details on processes such as carboxylation and electron transports, besides having the average temperature and CO2 concentration, important variables in the future scenario. It was used in this research daily meteorological informations, photosynthesis rate values and productivity as well, were obtained in a experiment in SP(Souza, 2007), and also air temperature data and CO2 projected by the model ECHAM5/MPI-OM ( scenario A1B) in simulations between 2005-2020. The results confirm the models answers well the CO2 and the air temperature increasing. The potential productivity projection of sugar cane was studied in the cities of Ribeirão Preto and Piracicaba. Two methodologies were made, the first one considering day degrees, the temperature increasing reduced the crop cycle and due to that, a smaller productivity. Ribeirão Preto had the biggest differences with 49% productivity reduction in 2012 when compared to 2005. The second methodology considering a constant sugar cane cycle, shows the temperature and CO2 increasing will cause a bigger productivity on the crop. The biggest productivity values were found in both cities in 2011 and 2012, the highest average temperature period and hottest winters in the series. The estimative of these periods, the potential productivity can reach values up to 66% higher than 2005 values. The results confirm that the studied model presented as an alternative to conventional models, warning about the differences between the two methodologies.