Ecofisiologia de Tabebuia heptaphylla (Vellozo) Toledo em ambientes contrastantes de luz

Abstract

Tabebuia heptaphylla (Vellozo) Toledo, popularly known as ipê-roxo or ipê-roxo-de-sete-folhas, is a plant of Bignoniaceae family, native from the Atlantic Forest. These plants are applied in economic, medicinal, ecological and urban landscape use. However, there is no sufficient ecophysiological information about this specie. In order to provide information about propagation and conservation of this specie, this study evaluated emergence, biomass accumulation and leaf anatomy and physiology of the species in contrasting light regimes. We carried out two independent field experiments. One was located in a remnant of Atlantic Forest, with treatments gap and understory. The other was made under controlled conditions, with two treatments: 70% shade and full sun. The results showed that: the species has ability to form seedlings at different light intensities, with emergency above 50% in all treatments; plants under full sun showed higher growth rates and biomass accumulation, however photoinhibitory damage occurred in this condition; in the understory, was slow growth, however the plants survived in this environment; plants grown in the gap had better photosynthetic performance; anatomical and physiological adjustments according to the light regimes were recorded. We found that this species has plasticity in intermediate conditions of light and they are sensitive to high irradiance during early growth.