Comportamento silvicultural e dinâmica de serapilheira em plantios de duas espécies florestais na Amazônia oriental brasileira

Abstract

The deforestation in the Brazilian Amazonia has already altered about 750 million hectares and of this total, 20% are found with some level of degradation. The reincorporation to the productive process of the areas altered with the reforestation of tropical species of commercial value, it is an alternative to minimize the environmental impacts, with ecological benefits, increase of the wood offer and decrease of the pressure on the remaining natural forests. However, one of the great difficulties for the reforestation is the lack of scientific knowledge on the growth of native and exotic species. This work had as objective evaluates the efficiency of different systems of plantings with native and exotic forest species for recovery of altered land. The work was accomplished in Dom Eliseu city, state of the Pará, in three systems of land use: pure planting (Schizolobium parahyba var. amazonicum and Khaya ivorensis), mix of two forests species (S. parahyba var. amazonicum and K. ivorensis) and agroforestry system (S. amazonicum and Musa sp). To The forty months of age, in planting pure, S. parahyba var. amazonicum showed larger growth in height and dbh in the spacing 4 m x 3 m and K. ivorensis in the spacing 4 m x 4 m. However, the S. parahyba var. amazonicum presented better performance in the system mixed planting and agroforest system. The best performance of K. ivorensis was in the mixed system of species. Among the planting systems studied (mix of species and agroforest system), the litterfall was more in the mix of species with 3.737,5 kg ha-1, and the largest contribution of biomass was of the S. parahyba var. amazonicum. The largest biomass reduction was observed in the agroforest systems. Was evidence correlation negative between litterfall and rainfall to S. parahyba var. amazonicum and positive for K. ivorensis. The obtained results showed that the forest model of consortium of species was shown promising and it can be an alternative for recovery of altered areas, in way to offer different wood options and at the same time, to join positive factors in relation to biomass production and physicchemistry aspects of the soil.