Emergência e crescimento inicial de Tabebuia heptaphylla (Vell.) Toledo em ambientes contrastantes de luz

摘要

Tabebuia heptaphylla (Vell.) Toledo, known as "ipê-roxo" or" ipê-roxo-de sete-folhas", is a native species of Atlantic Forest, with an economic, medicinal and ornamental role, suitable for reforestation. However, ecophysiological information about it is scarce. In order to provide information about propagation and conservation for this specie, the present study evaluated emergence and early growth of this species in different light exposure. We lead two independent trials. In the first we considered controlled conditions, with two treatments: 70% shade and full sun. The second was developed in a natural environment, with two treatments: gap and understory environments. From the total parameters used to evaluate the emergence of the species under influence of light intensities, only the emergence percentage was statistically different from the natural environment, with high values observed at gap treatment. Significant differences were observed in controlled environment, considering the emergence speed. This variable was higher in plants grown under full sun. Slower initial growth was observed for plants regenerated in the understory, compared to the plants growing in gaps, except for following characteristics: leaf area ration and specific leaf area. In controlled conditions, the results with higher significant differences were observed for plants under full sun. The study shows that the species has the capacity to germinate in different light conditions, even under strong natural shading. However, this condition reduces significantly its initial growth, which is favored by higher light intensities.