Ecofisiologia de Millettia stuhlmannii Taub em diferentes demandas atmosféricas e disponibilidade hídricas no solo

• Autor(a) principal: Ferreira, Elias Secretário Armando
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/5076
• topic: Gas exchange; Microclimate; Panga-panga; Trocas gasosas; Microclima; Recursos Florestais e Engenharia Florestal; 630

The Mozambican forest setting several native species has shown potential for silvicultural expansion. Among the species there is the Millettia stuhlmannii (commonly known by panga-panga) with high commercial value and that has contributed to the country's economy. However, there are few studies on the ecophysiological behavior of this kind across the soil and weather conditions, which could compromise the success of new projects. The present study aimed to investigate the physiological ecology of Millettia stuhlmannii in different atmospheric demand and water availability in the soil. The study was carried out in airconditioned greenhouses, located in the experimental area of the Department of Forest Science and Madeira in the Agricultural Sciences Center of the Federal University of Espírito Santo, located in the town of Jerônimo Monteiro - ES, using completely randomized design in a 2x4 factorial design, and the atmospheric demand factor on two levels (high and low) and the water availability factor on the ground on four levels of available water (100, 80, 60 and 40%), with five repetitions. The following morphological variables at the end of the experiment were assessed: total dry weight, shoot dry weight, root dry weight, leaf area, specific leaf area, leaf mass fraction, root mass fraction, mass fraction of the shoot, reason leaf area, root dry mass ratio by dry weight of shoot and efficient use of water productivity; physiological variables: net photosynthesis, stomatal conductance, internal CO2 concentration and transpiration and contents of photosynthetic pigments: chlorophyll a, chlorophyll b, chlorophyll a+b, carotenoids, chlorophyll ratio a/chlorophyll b and chlorophyll a+b carotenoids. Data were compared using the regression model by modeling identity test according to Chow (1960) for growth. For gaseous and photosynthetic pigments exchanges, it was held Tukey test (p = 0.05) using software SISVAR 5.1 Furtado (2011). The species exhibited reduced total dry weight, shoot dry mass, leaf area, leaf mass fraction, leaf area ratio, shoot mass fraction with the reduction of water availability in the soil independent of atmospheric demand; and increased root dry weight, root dry weight ratio by dry weight of shoot, specific leaf area, root mass fraction, use efficiency of water productivity by reducing water availability in the soil independent of atmospheric demand. However, the biggest accumulation of total dry matter, leaf area and most efficient use of water productivity was observed in high atmospheric demand. For gas exchange, net photosynthetic rate, stomatal conductance and transpiration were higher under high atmospheric demand and the opposite was observed for the internal CO2 concentration. In photosynthetic pigments, there was a decrease in strength with a reduction in water availability in soil, independently of atmospheric demand in chlorophyll b, chlorophyll a+b, carotenoids, chlorophyll a/b, chlorophyll a+b/Carot. Thus, the species had higher performance in high atmospheric demand, which reveals suit the tropical weather conditions.