Ecological and physiological aspects of C. guianensis, collaborating with conservation and management of andiroba

Abstract

Mercidito Oliveira and Erique V.E. and Anderson Roberto

The neotropical tree Carapa guianensis has several economic and medicinal applications, and is valued for both the high-quality oil extracted from its seeds and its mahogany-like wood. Recruitment and expansion of C. guianensis depend mainly on sexual reproduction. However, germination conditions for C. guianensis are poorly studied. This makes the understanding of its germination requirements vital for conservation and management. Laboratory studies were conducted to investigate the effects of three environmental variables (temperature, substratum and light quality) on the seed germination of C. guianensis. Our results showed that for seed germination, a temperature range of 30 to 40°C was the most favorable, and fertilized soil and water were more favorable than sand. Seeds in the dark germinated in higher percentages and in a shorter time. Removal of the seed coat accelerated the germination process for all conditions tested, except for green and red light, and darkness. Green and blue light retarded and red light stimulated seed germination. Plants under green light always grew taller than in the other treatments. Plants grown under blue light and in the dark showed the same profile after four weeks. Compared with sand and water, fertilized soil was the best substrate for epicotyl development. It was suggested that measurement of light quality can be used to estimate forest stand density, impact of silvicultural treatment and structural impact of anthropogenic effects on tropicalforest diversity.