Since 1978, 43,000 ha of plantations have been set up on the savannah around Pointe Noire. They have been found to be well suited to the conditions and, given an adequate silviculture of maintenance and fertilization, they perform well (20-25 m3/ha/year). However, little is known about the durability of production concerning the nutrient needs of the plantations, nor about the effect this intensive culture has on the variation in soil fertility. This question is particularly relevant to the 25,000 ha on their second and third rotation and those planted on sandy, acidic and chemically very poor soil. The sustainability of the plantations has therefore been identified as a priority for research